February 2006 Digital Edition of Circuits Assembly

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FEBRUARY 2006 circuitsassembly.com

X-Ray FluorescenceFluorescence LEAD-FREE WATCH 5 months Wafer-Level CSPCSP Countdown to July 1, 2006 Solder Joints Outsourcing RoHS-Compliant Production

Pb-FreePb-Free StencilStencil RequirementsRequirements

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©2005 EMA Design Automation, Inc. All rights reserved in the U.S. and other countries. EMA Design Automation, the EMA logo, and "Lead-Free by Design" are trademarks of EMA Design Automation. Cadence and the Cadence logo are registered trademarks of Cadence Design Systems, Inc.

Apex Show Issue

FEBRUARY 2006 circuitsassembly.com

X-Ray Fluorescence LEAD-FREE WATCH 5 months Wafer-Levelfer-Level CSP Countdown to July 1, 2006 Solder Joints Outsourcing RoHS-Compliant Production

Pb-Free Stencil Requirements FEBRUARY 2006 – Vol. 17 No. 2 Cover photo courtesy of DEK. Inset courtesy of ERSA.

AOI and Selective Soldering FIRST PERSON FEATURES Get Integrated, p. 50 ON THE COVER: The influence of 6 Caveat Lector Materials Declaration aperture designs on Pb-free assembly. Cookson gets reworked. 40 Full Disclosure Mike Buetow What are your parts made out of? It’s not so easy to know. 22 Talking Heads Michael Kirschner Valor’s Chuck Feingold and David Bengal. Pb-Free Printing Parameters Mike Buetow 44 Understanding Pb-Free Stencil Requirements This study of what happens when the process window is intentionally violated finds engineers should worry more about the effects of stencil geometries than a centered Pb-free print process. MONEY MATTERS Clive Ashmore 26 Focus on Business Technology Innovations Sustaining profitability through services. 50 Integrating AOI and Selective Soldering Dr. Jonathon Linton A breakthrough machine for PTH mass soldering combines AOI and selective soldering in a single inline unit. How it works, and the business case behind it. 30 Global Sourcing Mark Cannon, Bob Klenke and Phil Zarrow How to kill business by not even trying. EMS RoHS Models Greg Papandrew 56 Outsourcing RoHS-Compliant Production at a Distance TECH TALK How Beyonics tackled the Pb-free transition, and auditing advice for overseas customers. Eric Liew, Fadzol Zaman and Sivakumar Thanupillai 32 On the Forefront The “magic mix.” Supply Chain Solutions Dr. Ken Gilleo 60 The Supply Excellence Project at Ericsson and 34 Screen Printing Solectron Blending Lean and Agile concepts cut lead times by 75% on a complex, custom telecom product. Z-axis support options. Ylva Andersson, Jan Melin, Rolf Broström, Lindsay Ballantyne, Dave Cooper and Lennart Ivarsson Joe Belmonte Procurement 36 Better Manufacturing 64 The Future of PCB Procurement When profiling is a good thing. The battle for supply-chain ownership pits distributors vs. EMS firms. Phil Zarrow Mike Buetow 84 Soldering Tips Solder Joint Reliability A primer on x-ray fluorescence. 68 Crack Growth Rate Measurement and Analysis American Competitiveness Institute for WLCSP SnAgCu Solder Joints 86 Wave Soldering Using FEM, cracking is correlated with average inelastic strain and strain energy density. Mitigating common Pb-free defects. Paresh Limaye, Bart Vandevelde, Dirk Vandepitte and Bert Verlinden Gerjan Diepstraten Pb-Free Wave Soldering 88 Countdown to Pb-Free 76 Dynamics in Pb-Free Wave Soldering Don’t bank on an RoHS extension. A five-phase study of fluxes and convection preheating related to three Pb-free alloys revealed a few unexpected twists. Steven Andrews R.A. Szymanowski, D. Casati, E. Saglia, P. Lotosky, K. Howell and G. Hueste 90 Process Doctor Are your cleaning processes in control? Terry Munson DEPARTMENTS 92 Equipment Advances 8 Industry News 66 Ad Index Juki’s selective soldering series. 18 Market Watch 94 Product Spotlight 96 Technical Abstracts 57 Assembly Insider There’s No Time to Lose Don’t let lead-free leave you behind

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Henkel Americas: +1 949 789 2500 Henkel Europe: +44 1442 278 000 Henkel Asia: +852 2233 0000 electronics.henkel.com circuitsassembly.com Editorial Office (678) 589-8800 UP Media Group will relocate effective in March. Please visit circuitsassembly.com for the new address.

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Subscription Policy Circuits Assembly (ISSN 1054-0407/GST124513185/Agreement #1419676) is distributed without charge to qualified subscribers. To all others in the USA and Canada: US$80 per year. Other countries: US$145 per year (air service included, payment required in advance). Single copies US$8.50. Send requests for qualification forms and changes of address (include old label) to: CIRCUITS ASSEMBLY, P.O. Box 35646, Tulsa, OK 74153-0646, email: [email protected], fax (918) 496-9465. Periodicals postage paid at Atlanta, GA 30339 and additional mailing offices. Reproduction of text and illustrations is not allowed without express written permission. Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is grant- ed by UP Media Group, Inc. for libraries and other users registered with the Copyright Clearance Center (CCC) Transactional Reporting Service, provided that the base fee of $2.00 per copy, plus $0.25 per page is paid directly to CCC, 21 Congress St., Salem, MA 01970. 0009-7306/86, $2.00 + $0.25. 16mm microfilm, 35mm microfilm, 105mm microfiche and article and issue photocopies are available from University Microfilms International, 300 N. Zeeb Rd., Ann Arbor, MI 48106 (313) 761-4700. Canadian GST Permit 124513185. Opinions expressed by authors are not necessarily those of the publisher, and this publication can accept no responsibility in connection with any liability that might develop as a result of articles published. Circuits Assembly is published monthly by UP Media Group, Inc., 2018 Powers Ferry Road, Suite 600, Atlanta, GA 30339. POSTMASTER: Please send changes of address to CIRCUITS ASSEMBLY, P.O. Box 35646, Tulsa, OK 74153-0646.

circuitsassembly.com Circuits Assembly FEBRUARY 2006 5 Caveat Lector Cooking Up a New Look hat was quick. against that. First, Assembly Materials is the largest sin- In little more than the blink of an eye, Cookson gle unit within Cookson Electronics, and its return on T Electronics has reworked itself, selling off a pair of sales is consistently north of 8%. Second, Alpha’s sales divisions to fulfill a previously announced attempt to and distribution channels are tightly intertwined with concentrate on its higher growth businesses. those of other Cookson Electronics units; undoing that The chemicals conglomerate said Jan. 3 that it would be no simple task. And last, as Assembly Materi- would sell its conformal coating business unit, Special- als president David Zerfoss says, “Cookson is 150% ty Coating Systems, to an investment group (see News, committed” to the business. page 16). The news came just two weeks after Cookson Marketing aside, are these the right moves? They announced the long-anticipated sale of certainly weren’t unexpected. Upon assuming the top Polyclad Technologies, to Isola Group. job, Corbett alluded to CIRCUITS ASSEMBLY the possibility Cookson will garner an estimated $147 that changes were coming. The one-stop shopping million from the sales, once they go approach was “not a common thread” among Cook- through. son’s customers, he said. Of his predecessor’s strategy, So the remaking of Cookson continues. he said, “I’m not going to push it where it doesn’t fit … Under chief executive Steve Corbett, Cook- That’s probably the difference in our philosophies.” son Electronics has further splintered the But the reason for shedding various units is likely all-in-one strategy it followed under his more monetary than philosophical. Polyclad’s return predecessor. Beginning with the sale of on sales, a meager 0.6% in 2004, swung to a loss of Speedline Technologies, finalized in 3.4% through the first six months of 2005. Globally, November 2003, the company that once laminates are hampered by massive overcapacity and boasted of near end-to-end solutions in painful pricing pressure. Polyclad’s new owner, Isola semiconductor and printed circuit board (which is run by Sharpe), will likely have to take a buz- materials plus electronics assembly equip- zsaw to its workforce and footprint. By selling, Cook- ment now has a center of gravity rooted firmly in son avoided the chaos and public relations hit inherent chemistries and joining materials. in a shutdown. Under former CEO Ray Sharpe, Cookson Electronics As for SCS, it is smaller but by my guess more prof- spent 10 years gathering a slew of businesses under its itable than Polyclad. However, its focus is diverging umbrella, and Sharpe looked prescient when the tech rapidly: the unit’s growth is coming in medical devices, markets took off in the late 1990s. The bursting of the not electronics. bubble in 2001 was followed by the sale of then-hemor- Cookson these days is looking more and more like rhaging Speedline, which was jettisoned (given away, 3M and DuPont – diverse materials companies with some jest) to an investor group after losing $69.2 million legs in several industries. Insiders would insist they’ve on $197.6 million in sales (converted from pounds at always been that way, public perception notwithstand- today’s values) through the previous 21 months. That ing. Whatever the case, the once long shadow it cast business has since recovered and is looking very strong as over the electronics manufacturing world is shrinking, 2006 opens. and it’s unlikely that we’ll see another company quite In hindsight, 2000 marked a turning point in sever- like it anytime soon. al ways. Within parent company Cookson PLC, the EAB changes. It works behind the scenes, but the Electronics Group’s percentage of sales has been dwin- CIRCUITS ASSEMBLY editorial advisory board performs a dling over the past five years. Electronics made up 54% central role in shaping the content of the magazine. A of the company’s sales and 56% of its profits in 2000. warm welcome to this year’s members: Rich Breault, By fiscal 2004, the unit’s contribution to the company’s Sue Mucha, Chrys Shea and holdover John Borneman. revenue and profits had fallen to 39% and 45.9%, Also, a hearty “thank you” to outgoing members Bill respectively. Coker, Glenn Robertson, Mark Schwartz and Dick The falloff has had ramifications to Cookson’s pub- Vaughn for their contributions. lic persona as well. In public statements, the company Finally, CIRCUITS ASSEMBLY is exhibiting at Apex this has downplayed its once-hyped technology holdings, month. Please stop by booth 485 and say hello. instead choosing to position itself as an industrial materials science concern. Less sexy, sure, but also less Mike Buetow, Editor-in-Chief cyclical, which plays better with today’s analysts. [email protected] Is the selloff complete? I would think so. If not, given the staunch competition and contracting margins of the solder world, it would seem that Alpha Met- UP Media Group will relocate next month; visit circuitsassembly. als would be next on the block. Two factors argue com for the new address.

6 Circuits Assembly FEBRUARY 2006 circuitsassembly.com You’ve got months.

Contact our Pb-Free Process Experts Now: [email protected]

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INDI-1408CA.indd 1 12/20/05 2:03:10 PM Industry NEWS

Celestica Added to Xbox Supplier List Data I/O, Toyo Corp. Las Vegas – In an effort to cope with heavy demand for its Xbox 360, Partner in Japan Microsoft Corp. (microsoft.com) in January said it would outsource new production to Celestica (celestica.com). Redmond, WA – Data I/O (data-io.com) The Toronto-based contract manufacturer is the third EMS firm contracted to signed a multi-year distribution agree- build the video game console. Flextronics (flextronics.com) and Wistron ment with Toyo Corp. (toyo.co.jp). Toyo (wistron.com) already build the popular unit. will provide system installation, service Microsoft is on track to meet its goal of shipping 4.5 million to 5.5 million and device support updates for Data I/O consoles by the end of June. Founder Bill Gates said, “We think by the time we programming systems in Japan. get to the 4.5 million to 5.5 million unit level that the backlog won’t be all that According to a press release, Data I/O’s substantial.” programming solutions enable high-qual- He added that several new peripherals are expected by mid-year, including ity results in volume production of con- cameras and communications connections to allow text messaging between sumer electronics, wireless devices and the Xbox and PCs. automotive electronics assemblies. The Gates also said the company would have at least 50 high-definition games solutions program flash memory, micro- on the market by mid year. controller and DSP devices from device IN THE GAME: manufacturers such as Fujitsu, Samsung, Celestica added to Toshiba, Renesas, Microchip Technologies, IPC Puts Forth Board Slate Microsoft Xbox TI and others. – Robin Norvell Bannockburn, IL – Jim Herring, president and CEO of EMS firm Circuit Ser- 360 lineup. vice, has been nominated as the next chairman of IPC, the trade group announced. In all, IPC (ipc.org) announced nine candidates for its board, including all three officer Ft. Collins: The New positions. Silicon Valley? Herring was a commercial banker for 30 years before taking over Circuit Service in 1996. He has been on the IPC board since 2001, and is currently vice chairman. Per IPC bylaws, the slate of candi- Ft. Collins, CO – Once a site of a major dates will be approved by voice vote of select attendees at the trade group’s annual meeting this Hewlett-Packard manufacturing plant, Ft. month. If elected, candidates would serve a two-year term effective Jan. 1, 2006. Collins is becoming attractive to major Assembléon America president Mike Buscher was nominated as vice chairman. Buscher is a past chipmakers. Intel (intel.com), which chairman of the IPC SMEMA Council and has spent 30 years in electronics automation. Buscher has already employs about 300 on the former been on the board since 2001 and is a member of the Government Relations committee. Coretec chief H-P campus, will relocate its offices to a executive Paul Langston was nominated for secretary/treasurer. Langston, a second-generation PCB nearby 200,000 sq. ft. site recently pur- shop executive, has been a director since 2003. chased from Celestica (celestica.com). Current directors who are re-nominated include IMI president Peter Bigelow, a director for six of the Also, Intel competitor AMD (amd.com) past eight years; Electrochemicals vice president of marketing and strategic development Mike Cara- plans to bring as many as 200 electrical no, a director since 2004; Nu Visions Manufacturing president and CEO Steve Pudles, a director since design engineering jobs to Fort Collins, 2001; OneSource Group CEO Nilesh Naik, a director since 2002. reported the Coloradoan, a local online First-time nominees include Micro Dynamics CEO Michael Brown; Hunter Technology president Joe news source. The news source said AMD’s O’Neil; CTS Electronics Manufacturing Solutions president Don Schroeder; Dover Technologies presi- decision depends on the company’s abili- dent and chief executive Dave Van Loan; Parlex Corp., Shanghai president and CEO Alan Wong. ty “to find enough workers to staff a Nominees were chosen by current directors Peter Murphy, Herring, Bob Ferguson, Gerhard Meese, satellite office.” Steve Wohlgemuth, and IPC president Denny McGuirk. The new Intel site is located on 30 acres Directors who will remain on the board include Murphy, investment banker Jack Calderon, Speedline and was purchased for $13 million last president Pierre de Villemejane, TTM COO Shane Whiteside and Flextronics vice president Sammy Yi. year. According to various reports, Intel Former chairs Jim Donaghy and Ron Underwood remain as ex officio directors. could reap several incentives from the The makeup of the board continues to change. The current slate, excluding ex officio, is comprised county and state in exchange for locating of six candidates from EMS companies, five from fabricators, five from suppliers, and two (Calderon, in Ft. Collins. McGuirk) from “other.” When Celestica decided last year to In 2001, by comparison, the board was made up of four EMS representatives, 10 fabricators and two shut down its manufacturing operations suppliers, plus McGuirk. there, the site employed 800 workers. Through October, IPC membership was made up of 18.3% EMS companies, 13.6% PCB fabricators, 33.6% OEMs and 25.9% suppliers. The remainder were “other.”

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In Brief Congress Proposes Innovation Funding Washington, D.C. – The U.S. Congress, led by Senators John Ensign (R-NV) and Joe Lieberman (D- Ericsson (ericsson.com) purchased three CT), in December unveiled a proposal calling for a boost in R&D funding for basic and advanced sci- Orbotech (orbotech.com) Symbion P36 ence, in an effort to spearhead nationwide attention toward developing domestic engineering talent post-print AOI systems for its Kumla, Swe- and ideas. den, factory. Ericsson also selected Valor In a letter to colleagues, the senators said the bill “aims to make the necessary improvements in Computerized Systems’ (valor.com) Trilo- research, education of science and technology talent and innovation infrastructure to allow the Unit- gy 5000 Optimization software to increase ed States to maintain the global leadership it achieved in the last productivity of its Swedish site. century.” The bill responds to the recommendations made in the National Innovation Initiative report, “Innovate America,” issued AOI systems manufacturer Landrex Tech- late last year by the Council on Competitiveness. nologies (landrex-us.com) and ZD Test The National Innovation Act of 2005 calls for a national com- (zdefects.com) will jointly market, sell, man- mitment to basic research, and would nearly double the Nation- ufacture and distribute electrical test fixtures, including backplane and PCBA fix- al Science Foundation’s research funding from 2007 through tures for MDA, ICT and functional test. Also, 2011. Landrex named Ascentech as sales rep for In a Dec. 16 statement, the Semiconductor Industry Association the six-state New England territory. (sia.org) pledged its support for the bill. The proposal also calls on each executive agency that currently funds R&D in science, mathematics, EMS provider Synchronized Manufac- engineering and technology to commit at least 3% of its existing annual R&D budget to this program. turing Technologies (synchmfg.com) has The Department of Defense would be urged to allocate at least 20% of this amount toward basic achieved ISO-9001:2000 certification. research in science and technology. A total of $300 million between 2007 and 2011 would go to the National Institute of Standards and Kyzen Corp. (kyzen.com) appointed CCR Technology (nist.gov) to support R&D in the industrial sector to develop innovative, state-of-the-art as its manufacturing representative for manufacturing practices. Among the targets: improving advanced distributed and desktop manufac- Canada. Headquartered in Ontario, CCR turing capabilities, developing small lot manufacturing processes compatible with volume production (ccrkanata.com) will represent Kyzen’s full and applying nanotechnology to manufacturing. line of cleaning materials. Kyzen also named More than $475 million would be committed to graduate fellowships and other education support Creyr Innovation LLC (creyr.net). as its rep within the DoD. Another $111 million would go to universities and government agencies to fund grad- in New England. uate fellowships and training. The National Academy would receive $1 million for a yearlong study of potential barriers to private Zuken (zuken.com) signed an eight-year, sector innovation. $1.2 million contract to provide its CR-5000 The proposal includes a provision to make permanent the research credit of the Internal Revenue PCB design environment to Siemens AG’s Code. The credit, originally enacted in 1981, has been extended 11 times and was scheduled to expire Rail Automation Division (siemens.com/ Dec. 31. The tax credit should permit companies to engage more easily in long-term research projects. transportation). The proposal also calls for U.S. patent law reform to enhance the quality of patents, to leverage patent databases as innovation tools and to create best practices for global collaborative standard-setting. Aegis Industrial Software Corp. (ais Under the proposed act, the President would create a Council on Innovation comprised of heads of corp.com) will provide NPI and MES soft- executive agencies including Commerce, Defense, Education, Energy and others. The Council, chaired ware solutions for Variosystems’ (variosys- by the Secretary of Commerce, will have oversight over legislative proposals and executive branch ini- tems.com) facilities worldwide. tiatives for promoting innovation. The bill came shortly after a high level summit (usinnovation.org) on innovation and competitiveness. Production Testing Systems Ltd. On Dec. 6, more than 55 corporate CEOs, university presidents and scientists participated in a day-long (ptestsyst.com.cn), headquartered in Shen- summit during which they pressed cabinet secretaries and members of Congress for more R&D fund- zhen, will offer Geopel’s boundary scan ing; a greater emphasis on science, math and engineering education; immigration reform for highly products to the Asian market. PTS is the educated, high-skill foreign nationals; and support for development of advanced technologies. eleventh Goepel (goepel.com) Center of Commerce Secretary Carlos Gutierrez, Energy Secretary Samuel Bodman, Labor Secretary Elaine Expertise. Chao, Education Secretary Margaret Spellings and Deputy Commerce Secretary David Sampson were among those who discussed policy prescriptions for future economic success. Photocircuits Corp. (photocircuits.com) Shortly after the proposal was announced, the SIA released a statement announcing its “strong sup- has qualified to MIL-PRF-31032 and MIL- port.” “U.S. leadership in technology has been the cornerstone of America’s strategies for driving eco- PRF-55110. Also, the company’s managers nomic growth and ensuring national security,” said SIA president George Scalise. “The National Inno- are reportedly reviewing bids for a potential buyer. vation Act of 2005 addresses a number of the most critical issues involving technology leadership, especially those related to federal support for basic research.”

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In Brief Solder Vendors: Voiding Doesn’t Affect Joint Reliability Bannockburn, IL – A group of leading solder vendors in December issued a statement asserting “no Novatec (novatec-eap.com) appointed evidence” exists demonstrating voiding has “any significant impact” on solder joint reliability. Process Support Products Ltd. (process- In a statement, Karl Seelig, chair of the subcommittee that issued the report, stressed its findings on support-products.com)asits U.K. distributor Pb-free voids. “Based on the comparison of the number and size of solder joint voids to thermal cycle for VacuNest shape memory tooling. SMT interconnection failure date, there is no evidence that solder joint voiding has any significant impact Kompetenz (smt-kompetenz.de)was tapped on solder joint reliability.” to distribute in Germany. The report was issued over five months ago by the Solder Products Value Council, a group of vendors organized under IPC (ipc.org). The research is based on results of a three-year, $1 million test pro- Jabil Circuit (jabil.com) acquired the gram that studied the reliability of SnAgCu alloys. Texas operations of Incline Global Tech- The research further determined no difference in reliability between the SAC alloy family. In the nology Services (incline-gts.com), a flat- report, an alloy comprised of SnAg3.0Cu0.5 was recommended. panel display repair services company. The Seelig said the group compiled “excellent data” on the effects of solder joint voids on solder joint acquisition will expand Jabil’s offerings in reliability for SAC alloys. the LCD and plasma display services market. The group is making a public statement now because significant details over the much-debated Pb- free voiding might have been lost in the overall scope of the report, Seelig said. “That’s the reason the DownStream Technologies (down council has published a special report specifically on solder joint voids for Pb-free solder. We have the streamtech.com) opened its new corporate data and it was only a matter of reformatting it for easier analysis.” headquarters in Marlborough, MA. The report is available to IPC members and can be obtained through the SPVC technical subcommittee. The SVPC is made up of AIM, Kester, Advanced Metals Technology, Avantec, Cookson Electronics, EMS provider Nortech Systems EFD, Henkel, Heraeus, Koki, Metallic Resources, Nihon Superior, P. Kay Metal Supply, Qualitek, Mitsui (nortechsys.com) will purchase Telex Com- Comtek, Shenmao Technology, Thai Solder Industry Corp. and Indium. munications‘ (telex.com) 140,000-sq. ft. manufacturing facility in Blue Earth, MN, to UK DTI Puts WEEE under Review bolster its aerospace systems business. London – The U.K.’s top energy official suggested on Dec. 15 that the deadline for implementation Terms were not announced. of the Waste Electrical and Electronic Equipment directive would be pushed back. In a statement, Energy Minister Malcolm Wicks said progress on the implementation of WEEE is to Barric Ltd. (barric.co.uk), a contract man- be reviewed immediately. “We have listened to the concerns expressed by both the business commu- ufacturer, selected XJTAG (xjtag.com) as its nity and other stakeholders over the implementation process and have decided that more time is need- boundary scan test partner at Barric’s pro- ed to get the implementation right. Although any further delay is regrettable, this will ultimately deliv- duction facility in Norfolk, England. er far greater environmental benefits.” The announcement is contrary to an article written by Steven Andrews, head of the Department of Dow Corning Compound Semicon- Trade and Industry’s Eco-design and Product Policy Unit, and published in this issue. ductor Solutions (dowcorning.com) was In his statement Wicks did not place a new date for domestic compliance to WEEE, and reiterated awarded a $3.6 million contract from the the U.K. government’s support for the directive. He noted, however, the struggle many companies are U.S. Office of Naval Research (onr.navy.mil) encountering in implementing the new recycling law. “This government is firmly committed to sus- to develop semiconductor silicon carbide tainable development and recognizes that effective implementation of the WEEE directive has a key (SiC) materials technology. role to play in achieving this goal. “The directive is challenging and effective implementation of its obligations requires a lot of plan- AGS Pte. Ltd. (ags.com.sg) will embed ning and preparation. It is vital that the producers, retailers and the waste industry together with gov- Cogiscan’s (cogiscan.com) RFID Smart ernment have the appropriate plans, infrastructure and regulations in place.” Feeders in its refurbished placement Recovery targets were due to go into effect Aug. 13, 2005. CIRCUITS ASSEMBLY reported on its Web- machines. site in December that the government is considering a proposal to delay the legislation until June, with producer responsibility commencing next January. Data I/O (data-io.com) and Microchip The WEEE directive requires producers to pay for treatment and recycling or recovery of all WEEE Technology (microchip.com) will cooperate products. Under the law, retailers are obligated to offer takeback services to householders and will be to develop their customer bases. Microchip providing a network of collection facilities where consumers can take back their WEEE for it to be col- provides microcontroller and analog semi- lected separately from other municipal waste. conductors; Data I/O makes device program- Wicks said Energy officials would work with Defra and the Environment Agency to provide guidance ming systems. on draft regulations and guidance this spring. Defra handles certain aspects of domestic implementation, including drawing up guidance on how CTS Corp. (ctscorp.com) won a $32 mil- WEEE must be treated, waste permitting, assessing producers’ compliance with the collection, recy- lion deal to build an electronic throttle con- cling and recovery targets. The Environment Agency is responsible for enforcement. trol accelerator pedal module for a major Liz Parkes, head of waste regulation at the Environment Agency, said: “While we are keen to see pro- Japanese automobile manufacturer. Produc- ducer responsibility implemented for WEEE, we want to be confident that it will deliver real benefits tion is scheduled to start in July 2007. for the environment. We welcome DTI’s announcement and will be supporting the policy review to ensure that implementation imposes the minimum regulatory burden for all concerned.”

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People Report: Further M&A Among Distys Expected San Francisco – 2005 was a year for consolidation among distributors, and market conditions will Paul Barsley was named Celestica vice drive further merger activity in 2006, an analyst said in December. president, design and engineering services. In 2005, Avnet bought Memec, Arrow acquired Ultra Source, and World Peace teamed with SAC and He was founder and COO of Vocera Com- RichPower. Also, Yosun acquired two smaller Asia-based distributors for Texas Instruments. munications. He also spent 13 years at IDEO “Look for more of the same in 2006,” wrote Carter Shoop, an analyst at Deutsche Bank (db.com), in Product Development consultancy as COO a Dec. 9 research note. Shoop said that lack of growth in North America and Europe, “coupled with and VP of engineering. incentives from suppliers to develop a more comprehensive Asian footprint and pressure from customers to offer a broader line card, are driving consolidation in the fragmented Asian distribution market.” James Ying was promoted to vice president of operations at WKK Distribution Ltd., Automotive Could Drive Jabil Growth, CEO Says a new post. He was previously vice president St. Petersburg, FL – The automotive electronics market is primed for outsourcing, Jabil Circuit CEO in Southeast Asia. Tim Main said in an interview published in late December. Main told Forbes.com that the combination of higher elec- Bliss Industries promoted Mike Prieb tronics content in vehicles and “an intense need” for auto mak- (right) to sales manager. He ers and their suppliers to cut costs bodes well for “great long- joined the company in term growth.” According to Main, less than 10% of automotive 2002 as account manager. electronics are currently outsourced. The value of the captive The com- market is about $50 billion, Main estimates. pany hired He declined to offer a growth estimate but said he would not FAST LANE: Jabil sees big gains Alfredo be surprised if the segment showed double-digit returns in the in auto electronics. Grulich (left) as account near term. manager. Grulich previously He added that consumer electronics makes up $2 billion in sales for Jabil (jabil.com) and is the EMS worked as account execu- firm’s largest segment, yet its vertical nature suggests “tremendous” opportunities for outsourcers. tive at Teleset Inc. Separately, Jabil reported its fiscal first quarter profit climbed 38% on strong demand for consumer electronics and telecom gear. For the November quarter, Jabil earned $76.9 million, up from $55.9 million a year ago. Revenue rose 31% to $2.4 billion from $1.83 billion last year. Jeff Winzeler will fill the new position of chief operating officer at IDW. He remains the company’s chief financial officer. Simclar Acquires Litton Interconnect Technologies Hialeah, FL – EMS provider Simclar Inc. will buy Northrop Grumman’s Litton Interconnect Technolo- Interconnect Devices Inc., a maker of ATE gies assembly business in the U.S. for $28 million. Simclar’s (simclar.com) parent company has agreed spring probes, promoted Karen Bock to to acquire certain assets of the Litton assembly businesses in the U.K. and China through its subsidiary vice president of marketing. She was for- Simclar Interconnect Technologies Ltd. merly quality control manager and applica- Simclar will pay $16 million for Litton’s business (littoninterconnect.com) in Springfield, MO. The unit tion engineer. will be renamed Simclar Interconnect Technologies Inc. As the transaction includes the acquisition of a Chinese company, it is conditional upon approval by the China government. Viscom AG named Gerd Litton Interconnect Technologies supplies backplane interconnects. Simclar Inc., a unit of Simclar Rademann general direc- Group Ltd., has six North American manufacturing locations. tor of sales. He was previously in sales at Panasonic’s Sanmina to Acquire Adaptec’s Singapore Ops Assembly Machines divi- San Jose – Sanmina-SCI has signed a multi-year deal to build PC peripherals for Adaptec Inc. As part sion for 14 years. of the deal, Sanmina-SCI (sanminasci.com) will also take over certain Singapore manufacturing assets and inventory from Adaptec (adaptec.com). The deal was expected to close in January; no financial EMS firm Winland Electronics promoted terms were announced. Greg Burneske to vice president of engi- Under the agreement, Sanmina-SCI will build data protection, connectivity and storage products for neering, from director of engineering ser- Adaptec. Adaptec will take charges of up to $6 million to cover severance to its Singapore employees. vices. Burneske has 18 years of new product In a press release,Adaptec president and CEO S. “Sundi” Sundaresh said, “As we continue our analy- development experience and is a former sis of Adaptec businesses and operations, we are identifying areas where associating with strategic manager of analog and RF systems group at partners will allow Adaptec to focus on our core value of delivering advanced RAID data protection Plexus Corp. technology to our OEM and channel customers worldwide. Manufacturing is one of those areas where a partner like Sanmina-SCI can bring additional expertise and efficiencies to the table.”

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People IEC Bails on RoHS Marking Specs Geneva – The International Electrotechnical Commission (iec.ch) has decided not to publish a stan- The ESD Association certified the following dard covering the marking and labeling of products designated as Pb-free or RoHS compliant. persons as ESD Program Managers: Kevin According to a news report from a European Pb-free observer called ELFNET, the trade group report- Duncan and Robert Perry, Seagate Tech- edly said it would instead produce a technical specification with proposals for marking presence or nology; Carl Newberg,River’s Edge Tech- non-presence of substances. In doing so, the report said, IEC turned down a proposal from IPC nical Service; Douglas Miller, Sandia (ipc.org), which has pending standards for marking and labeling. National Laboratories; Thomas Larson, Ironically, IEC TC91, the committee responsible for such standards, is chaired by Dieter Bergman of IPC. Trek Inc.; Timothy Prass, Raytheon. At its September meeting, the committee decided to drop the standard on the basis that the number of labeling formats in place would make consensus unlikely. In April, TC91 will instead take up VJ Electronix appointed Raymond drafting a general technical specification, using a Japanese proposal as a starting point, the announce- LeFleur as manager of its new Asian sup- ment said. port center. LeFleur has 18 years’ experience ELFNET,a Website for Pb-free news in Europe, reported TC91 committee member Walter Huck as say- in x-ray and rework systems at Teradyne, ing, “An RoHS-compliant label cannot be standardized” because 1) no mandate by the EU Commis- GenRad, Nicolet X-Ray Systems and SRT. sion exists; 2) the speed with which RoHS compliance changes renders any mark or label meaningless; 3) labeling PCBs or equipment manufactured “under the scope and consideration of RoHS” is not the DiagnoSYS named Dave Miller Eastern same as detailing compliance information. region sales director. His previous employers include GenRad, Analog Devices, Teradyne, Solectron Adds Design Center in Europe Mantech, IMS and Eagle Test Systems. Timisoara, Romania – Solectron (solectron.com) has opened a design and engineering services center in Timisoara, its largest European facility. The added capabilities will enable electrical and mechan- Photo Stencil hired Mike Burgess as ical design, advanced process technology, leading edge test development and failure analysis. stencil product manager for North America. Solectron is the largest private employer in the Timisoara region. The site serves major OEMs in com- He has 20 years experience in manufactur- puter, telecommunications, digital consumer and industrial markets. “We’re seeing a definite increase ing, sales and marketing and was previously in customer demand for … product design and engineering,” said Dave Purvis, executive vice presi- senior district sales manager at Cookson dent and CTO. Electronics Assembly Materials. According to the company, creating a competitive design execution center in Europe is a core element of the company’s global strategy. “The proximity to our customer base, highly competitive cost structure and strong local pool of technical talent all point to Timisoara,” said Purvis. Separately, on Dec. 12 Solectron opened a dedicated medical products manufacturing plant. The Sin- Kemet to Acquire Epcos gapore Medical Center of Excellence is sited in Chai Chee, Singapore’s Techno Park, and will build high- Tantalum Caps Unit performance liquid chromatographs and fluidics subassemblies. The center will also refurbish medical and diagnostic medical equipment and devices for resale in China. – Robin Norvell and Mike Buetow Greenville, SC– Kemet Corp. (kemet. com) has announced a definitive agreement to purchase the tantalum capacitor SCS Sold to Investment Group business of Epcos AG for $101.9 million. Jersey City, NJ – New year, new owner. On Jan. 4, Cookson Group PLC announced the sale of its con- The deal is expected to close this spring, formal coating business unit to an investment bank for $55.5 million in cash. subject to standard closing conditions and Bunker Hill Capital purchased Specialty Coating Systems (scscoatings.com) for an immediate cash receipt of required regulatory approvals. payment of $54 million, with the balance due upon closing of the sale of the SCS China business in For the fiscal year ended Sept. 30, the early 2006. Epcos business (epcos.com) had revenue of In a statement, SCS president and CEO John Fry said, “The acquisition of SCS represents a seamless about 88 million euros ($103.7 million). and exciting change for our company and customers. While our visual brand will be updated over the The purchase includes the Epcos manu- next few months, our core focus will continue to be an unyielding commitment to the needs of our facturing operation in Evora, Portugal, and customers and markets. SCS remains committed to delivering the highest quality of services and prod- certain R&D, marketing and sales func- ucts to our worldwide customers.” Cookson’s sale of SCS was its second major divestiture in two weeks. The company announced the tions in various German locations. sale of its laminates division, Polyclad Technologies, in mid December. Kemet said the deal does not cover “SCS is an excellent business with both strong financial and product technology foundations, how- Epcos’ Heidenheim, Germany, manufac- ever its future growth is not strategically aligned with Assembly Materials Group’s markets,” said turing plant, but that Epcos will continue Cookson Assembly Materials Group president David Zerfoss. to supply product from the plant to Kemet SCS includes a group of companies, including its Parylene conformal coating used in medical, elec- until later in 2006. At that time, Kemet tronics and automotive applications, and an equipment business. Sales to major medical OEMs have will purchase and relocate the equipment overtaken electronics, which makes up about 25% of SCS’ revenues. in Heidenheim to China. The company, headquartered in Indianapolis, will continue to do business as Specialty Coating Sys- tems. It operates 10 coating facilities throughout the Americas, Europe and Asia.

16 Circuits Assembly FEBRUARY 2006 circuitsassembly.com

Market WATCH

Military Products Marching On Trends in the U.S. electronics equipment market (shipments only). Japan’s Electronics ------% Change ------Production to Rebound Sept. Oct.r Nov.* YTD % Tokyo – Electronics production in Japan Computers and electronics products -1.7 0.8 -0.8 9.9 fell in 2005 but will rebound in 2006. Computers -8.2 8.7 -0.2 34.8 That’s according to the Japan Electronics Storage devices 7.9 -9.6 1.2 7.7 and Information Technology Industries Other peripheral equipment -0.7 1.2 -2.8 -4.8 Association (jeita.or.jp). Nondefense communications equipment 1.3 -2.2 -5.3 4.8 JEITA forecast domestic production of Defense communications equipment -7.3 8.2 -3.6 9.9 $161.4 billion for 2005, down 3.5% from A/V equipment 0.0 1.7 0.1 6.5 revised 2004 figures. The trade group had Semiconductors -2.9 -1.8 3.9 5.1 previously guided for a 2.8% gain. Components1 3.4 -3.0 -2.9 18.8 In a report issued Dec. 22, JEITA blamed Nondefense search and navigation equipment -10.8 -3.2 3.8 7.5 a lingering inventory adjustment that began during the second half of 2004 and Defense search and navigation equipment -2.9 3.0 -4.9 8.8 lasted about a year. Medical, measurement and control 0.8 2.7 -0.1 0.1 Production in 2006 is expected to grow r 1 Revised. *Preliminary. Includes semiconductors. Seasonally adjusted. Source: U.S. Department of Commerce Census Bureau, Jan. 4, 2006 2.3% but will not match 2004’s results. Next year’s gains will be driven by digital No December Freeze for U.S. Production consumer electronics, flat-panel TVs and Tempe, AZ – The PMI index of U.S. manufacturing dipped in December but grew overall for the 31st car navigation systems. JEITA forecasted straight month. The December mobile phones to grow 7% and radio com- PMI was 54.2%,down 3.9 points Aug. Sept. Oct. Nov. Dec. munications systems to rise 6.9%. Overall from November, according to the PMI 53.6 59.4 59.1 58.1 54.2 sales of consumer electronics will rise 2.5% latest Institute for Supply Man- New orders 56.4 63.8 61.7 59.8 55.5 to 2.6 trillion yen, JEITA says. agement (ism.ws) poll. A score Production 55.9 63.1 62.0 60.6 57.0 over 50% shows expansion. The December PMI indicates Inventories 45.7 49.6 48.1 49.3 47.2 Connector Prices that both the overall economy Customer inventories 46.5 44.5 41.0 43.5 48.0 and the manufacturing sector Backlogs 50.5 55.0 55.5 53.0 49.5 Stabilizing are growing, ISM said. Chairman Source: Institute for Supply Management, January 2006 St. Charles, IL – Price erosion of surface- Nobert Ore said, “In December, mount connectors during the past five we saw a decline in the rate of growth of both new orders and production, but both indexes are at levels years has been significant and painful, that support economic growth.We saw a significant slowing in the upward pricing spiral that has been a says Bishop and Associates (connector source of continuing concern for manufacturers.A strong fourth quarter should carry significant momentum forward into 2006.” industry.com). For the month, new orders slid 4.3 The research firm cites as the main rea- IDC: More Growth in Store for Global PC Market points to 55.5%, while production son the migration of manufacturing to 2004 2005* 2006* 2006 % Change fell 3.6 points to 60.6%. Backlogs China. “There is no doubt that connector U.S. were down 3.5 points. Inventories at prices have been significantly influenced Consumer 21.8 23.6 25.6 8.7% manufacturers and customers by the lower costs [of China]. The lower increased 4.5 points. Employment Business 36.5 40.6 43.8 8.1% prices are a function of the lower manu- dipped 3.9 points, to 52.7%. Total 58.3 64.2 69.5 8.3% facturing costs.” The categories of electronic com- Once the manufacturing migration to World ponents and equipment, and indus- China has “run its course” and China Consumer 64.3 77.5 86.0 11.0% trial and commercial equipment prices are fully implemented, connector Business 115.1 130.2 143.5 10.2% and computers both reported growth during the month. prices will stabilize, Bishop said. “In effect, Total 179.4 207.7 229.5 10.5% The December PMI corresponds the China influence on lower prices is a In millions of units. *Estimated. Source: IDC, December 2005 to a 4.2% increase in real GDP. one-time occurrence. That is, once China pricing is in the marketplace, connector Industry Market Snapshot prices stabilize and stop declining. Once the lower costs are passed along, it’s over. Book-to-bills of various components/equipment. There is no more to give the OEMs.” July August Sept. Oct. Nov. Prices have begun to level, Bishop 1 Semiconductor equipment 0.93 0.97 0.90 0.95 0.92 wrote, saying industry feedback “suggests 2 Semiconductors 0.3% 3.2% 5.2% 6.75% 7.2% that the 7 to 10% price erosion of the Rigid PCBs3 (North America) 0.99 1.01 1.07 1.14 1.12 past few years has slowed to the histori- Flexible PCBs3 (North America) 1.71 1.62 1.52 1.10 1.16 cal norm of 3 to 4%.” Sources: 1SEMI, 2SIA (3-month moving average growth), 3IPC

18 Circuits Assembly FEBRUARY 2006 circuitsassembly.com (UMI3EAL!DFORPRINTPDF0- Perhaps you’ve heard a lot of

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Tokyo Shanghai Shenzhen Beijing Singapore Raleigh Sa work is going to China lately?

The Lowest Cost of Ownership - Period n Jose Sao Paolo Buenos Aires Nuremberg Nurnburg London Switzerland Talking Heads Stepping Aside, But Not Out

hen Valor Computerized Systems Ltd. (valor. implementation of best practices will be key for Valor’s com) was launched in 1992 (the North Amer- growth. W ican arm, Valor Inc., came online in 1993), the As a board member I look to contribute toward company had one product – a data vaulting system – Valor’s stated objective to exceed the $100 million rev- and a vision to be “partner to the electronic industry’s enue mark while becoming the premier software solu- quest for a truly efficient design-to-manufacture tions provider for engineering and manufacturing solu- process.”So said Chuck Feingold, president and founder tions to the electronics assembly market. It is my of Valor Inc., in a press statement in December 1999. expectation that it will be a “hands on” approach, as I Today, the software company has become a vibrant have always been a strong believer that the rubber meets and vital link in the manufacturing chain. In October, the road where our products come in contact with our Valor Ltd. posted its 10th straight quarter of customers. The board needs to be in touch with reality. growth. Its boasts a line of products includ- Valor board members will continue to travel globally to ing ODB++, the data exchange format, plus see what is happening in the field. tools for designers, fabrication, assembly and test. It has two JVs under its belt, including a CA: Looking back on your career so far, what successful partnership with TraceXpert, stands out as your greatest achievement? whose eponymous tool was Valor’s hottest CF: I do not see it as a personal achievement but I am item last year. very proud to have been part of a company that has After 13 years at the helm, Feingold is contributed so much in bridging the gap between the stepping down from day-to-day manage- electronics design and manufacturing worlds. Starting a ment of the U.S. operations and becoming a company in one’s living room (my kids were restricted director of company. (At to the pool for the first summer – press time, a successor had tough love), and seeing a vision come Outgoing Valor Inc. president not been named.) There will be a to fruition are nothing short of a Chuck Feingold Meanwhile, with a dream come true. dominant share of the market for "niche revival of assembly software, Valor has set its CA: If there were something you sights on tackling the next big need the vertically could do over, what would it be? for manufacturing engineers: getting CF: There are many things that the myriad equipment sets to feed integrated OEM." could have been done better, but reports into a common database. And weighted by importance I would while no one would confuse Valor with Oracle, the data- probably set a better balance between family and work. base giant, the former has one huge advantage: its pene- There is no rewind button on life. Notably, the family is tration and knowledge of the electronics manufacturing still fully intact (thanks gang). market. In separate interviews, CIRCUITS ASSEMBLY spoke with Feingold and Valor Europe president David Bengal CA: We’ve had many conversations over the years on the company’s future. about data transfer formats. What’s your take on how the industry is handling that bugaboo today? CA: What advice do you have for your successor, CF: Interestingly enough, the long debates that and what type of role do you plan to assume? brought ODB++’s emergence as an industry standard CF: In advising my successor I believe that it is (today, IPC-2581) elevated an awareness that change was important to help Valor Inc. adapt to the changes in the amust, ultimately driving toward a solution. Today the North American and Latin American marketplaces, industry is united behind IPC’s work, which is expanding while recognizing these markets’ influence in the global IPC-2581, and I believe it will emerge as a strong vehicle market scheme. This has several distinctions. North for data transfer from design not only to manufacturing America is still a major driver of technology as the but through test and box-build.I’d like to take this oppor- largest consumer market. Latin America is making a tunity to note Jim McElroy and iNEMI’s part in acting as good comeback, competing effectively with the Pacific a catalyst between Valor and IPC on this project. Rim. Valor tools play a significant part in helping OEMs as well as EMS companies move products from concept CA: Valor has set its sights on gaining traction in to market more efficiently in time and profit. We need the MES space with the mid- and small-tier players. to help the industry embrace best practices, whether What do you foresee for this group? vertically integrated or through outsourcing. Taking an CF: Although this is not in any way our growth active role with our customers in the execution and market – which is the large OEM and EMS suppliers

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See us at APEX, Booth #2635 Talking Heads –here is a prediction for the North American mar- CA: You also have some thoughts on the future of ket. The same way that 20 years ago the bare-board vertical integration that run counter to conventional PCB manufacturers took off with Diceon, Sanmina, thinking. Hadco, Zycon, etc., there will be a similar exponential CF: I forecast the niche revival of the vertically inte- growth of Tier III EMS companies that are able to grated OEMs, represented by companies such as Bose, support major OEM groups in ways the Tier I can- Symbol, General Dynamics and others, some of which not, in terms of flexibility and responsiveness. Valor have hired ex-EMS patriots to manufacture in-house. is in a unique position to help this tier deliver the These companies will most likely not be in the high vol- highest level of concurrent engineering and manufac- ume consumer market but rather hold strong market turing technology in support of their customers. I positions in their respective niches, where they want to believe Tier II EMS companies will either become control and maintain product IP.With the strengthening Tier I and cross the $2 billion revenue mark or cease of global economies, I believe they feel more in control of to exist. their destiny with some manufacturing in-house. ■

The ‘Manufacturing Dashboard’

alor Europe president David Bengal talks about small for Oracle. The customer would drive whether product traceability, automation and the com- RFID, bar code, etc. was used. V pany’s vision of ERP/MES tools. Machine vendors are scared of third-party MES tools because they allow the manufacturer to use mul- CA: With lead-free looming, there’s more empha- tiple equipment sets. Today, Genesis, the Valor tool for sis on traceability. How has the market reception PCB fabricators, has about an 80% share of the market been for Valor’s MES tool, TraceXpert? for assembly. Yet fabrication is an untapped market; the DB: TraceExpert has been by far the best- machines do not communicate to ERP systems and selling product for Valor this year. And the fabricators are blind to what’s going on at the machine merged cultures of Valor and TraceXpert A/S level. To measure cost, material management is needed. [now Valor Denmark] have worked well. And that means a real-time ERP system. Without an accurate timeline for ERP, the system cannot properly CA: What does Valor have in store? manage material control. DB: Valor’s vision does not call for This also encompasses resource allocation. This expanding our solutions down the supply means putting the right people in the right place on the chain. Our focus is more on assembly and floor, and redistributing the number of people on the manufacturing. We are expanding vertically floor. Without a good monitoring system, people in those markets first. become the monitoring system. That costs money. Our Valor has the ability to monitor informa- goal is to help our assembly customers automate their Valor’s David Bengal tion on the SMT line. Our goals are to processes. expand into manual assembly and box build, and help Our customers differentiate themselves on cost and customers turn SPC and other databases into knowl- quality. Customers try to achieve lower DPMO rates, edge to create meaningful data for the customer. By hence, we are aligning ourselves with Quality tools. this, we believe reporting tools aren’t scratching the surface of what the database could provide. We want to CA: Where does TraceXpert fit in to this? create a “dashboard” for the manufacturing manager DB: TraceXpert helps control an already optimized who sits outside the factory floor and helps decision- process. making based on real-time and historical data. Also, we want to extend quoting to include known operating CA: How would you characterize Valor’s penetra- expenditures of the line. A third goal is to develop a tion in Asia? higher level ERP/MES. DB: Our greatest challenge is making sales in China. We are putting more focus on this market. We are CA: Manual assembly would be a new area. How building relationships with Chinese companies as well do you add automation there? as leveraging our relationships with global companies DB: For manual assembly, we are looking at feeding that operate in mainland China. ■ information from scanned kits, staff and so on. It is aimed at small- to mid-tier companies, companies too

24 Circuits Assembly FEBRUARY 2006 circuitsassembly.com For RoHS-compliant solder products, AMTECH has We’ve all the answers. made

Everyone has questions regarding pending deadlines for compliance with the European Union’s new RoHS lead-free directive. Fortunately, AMTECH has all the answers, including a complete line of environmentally friendly lead-free solder products. AMTECH offers: lead- • Solder paste • Solder spheres • Solder powder • Solder preforms • Core wire • NVOC liquid flux AMTECH lead-free solder pastes are made from world class AMT Unisphere™ powder for enhanced solderability, which contains <200 ppm of lead, guaranteed. AMTECH is also your exclusive source for SynTECH-LF, a unique lead-free, no-clean solder paste formula made with proprietary synthetic poly-adduct free components. SynTECH-LF has been proven to increase process line yields with less beading, scrap and rework. For sensible answers to all your lead-free questions, call the experts at AMTECH. easy. It’s that easy. AMTECH www.amtechsolder.com 75 School Ground Rd., Branford, CT 06405 USA (800) 435-0317 • (203) 481-0362 • Fax (203) 481-5033

FILLING THE VOID

See us at APEX, booth #812 Focus on Business The Value of Services Services are the key to sustaining profitability in manufacturing.

ome of the most profitable firms during the 1990s tion at the time that they managed the sale of their man- were companies that used their position as a manufactured goods from a service perspective.5 In an envi- S ufacturer to offer high-margin services that lever- ronment that prevented free market forces and compe- age product-related skills and competencies.1 These firms tition, firms were in a position to charge higher prices. It have moved downstream into services that closely relate to would be a mistake, however, to suggest that the provi- their products. For example, Boeing provides parts sion of services is related to firms with monopoly pow- replacement contracts that supply customers – airlines – ers and that product purchase is related to firms operat- needed parts at desired locations. A number of airlines ing in either free or competitive markets. contract with Boeing for parts provision at the same air- Services often produce superior value for customers. ports.These airlines save money because they reduce their This creates the opportunity for greater profitability. cost of maintaining repair parts, and Boeing is able to Supplying services to customers facilitates a better charge a high margin on this service. General Electric not understanding of a physical product’s value proposition only sells locomotives, but provides financing and main- to an individual customer. By gaining a better under- tenance services. Finally, automotive companies have standing of the differences in relative value and the basis rediscovered that the sale of an automobile is not a one- of the value of a product for each customer, the manu- time event, but an opportunity for the initiation of a long facturer can customize a goods and services package series of relationships. Whether a lease or sale, tremen- and price it in such a way that both the customer and dous opportunities exist in financing, maintenance ser- seller obtain great value. Not only is there a tendency for vices, extended warranties and replacement parts. higher profits for the manufacturer, but customer loyal- Wise and Baumgartner estimate the purchase price ty increases since the manufacturer provides a customer of a product to be from 1/5 to 1/20 of the total product- with what they want. related expenditures for many large purchases. Few The tremendous potential of value-added services firms pursue the potential multiplier effect that services for the manufacturer is effectively a call for: can have on sales and overall profit, however. In many •Development of services that leverage the manufac- cases a firm may reluctantly move into the provision of turer’s knowledge of its product. a service at the request of a customer.2 For example, •Development of services that can assist/be sold to Caterpillar3 initially did not want to enter into remanu- the existing customer base. facturing. Over time, however, remanufacturing opera- •Actions or activities to bring the business closer to tions have been recognized as an important and prof- customers and end-users of the product. itable part of its business. •Further consideration and study of the develop- Even if product volumes and margins were not on ment and management of services related to manu- the decline in many traditional manufacturing business- facturing.6 es, the sales and profit multiplying potential of related Examples of value-added services that can add to the services are exceedingly attractive. It may seem that bottom line include: Jonathan Linton, moving downstream or integrating product-related ser- Training. It is unlikely that any organization has a professor at vices to the sale of products is not widely pursued greater knowledge and expertise than the OEM. Conse- Rensselaer Polytechnic because the concept is new. But in fact the utility of ser- quently, the OEM is in a superior position to offer this Institute (rpi.edu), vices were forgotten for a while and have recently been high margin service. Plus, the OEM already has an researches technology rediscovered. Many successful firms in the past have existing relationship with all the purchasers of the and operations approached their products from a service perspective. equipment. management; Years ago AT&T did not sell telephones. Telephones were Financing. In some cases a customer may prefer to [email protected]. His provided for a monthly fee. Similarly Xerox charged pay for a product at the time of purchase. But many column will appear firms for the service of having a photocopier.4 And IBM customers must finance the purchase of a product and four times a year. has a long history of providing equipment for a month- prefer suppliers to manage financing. Financing can ly fee. Equipment that provided a higher level of service, also be exceedingly profitable as shown by GE Capital for example a punch card reader with a higher process- and GMAC – the financial services business units of GE ing rate, was provided at a higher fee. These business and GM, respectively. models with a high level of service tend to offer greater Replacement parts. Replacement parts are typically revenue, and also a higher profit margin on the revenue. sold at a high margin. In some cases, the product is sold at There is, of course, a pattern between these three exam- cost or at a loss7 with the intent of profit being obtained ples: AT&T, IBM and Xerox were all in a monopoly posi- from the sale of consumable or replacement parts.

26 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Focus on Maintenance. An OEM’s expertise with equipment Other Models Business can be combined with advanced sensors and remote Design of services into the product. Sensors, computer communications to offer a variety of maintenance ser- processing power and remote communication make it vices including predictive, preventative and unsched- possible to add intelligence and flexibility into a prod- uled repair. Many organizations are prepared not only uct that permits the deskilling of tasks and improve- to draw on the expertise of the OEM, but the opportu- ment in performance, troubleshooting and mainte- nity to reduce the need for keeping specialized repair nance. For example, Bosch has placed a data-logging and maintenance skills in-house. chip into its power drills. This helps determine the Operations management. A variety of specialized skills amount of useful life left and whether the product is a may be required for the operation of the product. Some good candidate for remanufacturing. users prefer to outsource product operations to the One-stop shop. Provision of a good, and all related OEM or a third party. Product lifecycle management. Various services can be offered that address other aspects of the product life cycle. For exam- Lead-free Books ple, offering extended warranty coverage is increasingly commonplace. Other examples: trade-in arrangement, end-of-life product take back and upgrade of products. Leasing product. May be a preferred way to by finance the product. Alternatively, it might Jennie Hwang involve providing the product for a specific PhD period of time with the expectation of the ownership of the product reverting to the OEM at the end of the contract. In some cases it is not clear at the initiation of the lease whether the lease contract will end with the permanent ownership resting with the supplier or the customer. Making a Smooth Transition to Lead-Free System Leasing use. Involves the provision of the _Lead-Free Manufacturing Know-How product to a customer with ownership being _Manufacturing Approaches & Options _Real World Successful Lead-Free Production Examples retained by the supplier. However, instead of _System Reliability & Compatibility charging the customer a rate based on the _Lead-free Technology & Fundamentals amount of time the product is being leased, TO ORDER: the customer is charged on a use basis. Tech- Online: www.LeadFreeService.com Fax: 216-896-0405 nological advances in sensing, data collection, remote communication and electronic billing increase the viability of this option. Parts maintenance. Involves the supply of spare parts to the customer. With parts Publisher: Publisher: McGraw-Hill Electrochemical maintenance agreements, the supplier guar- U.S.A. Publications Great Britain antees that a group of desired parts will be 507 pages available within a given period of time. In 900 pages some cases the guarantee involves the storage of parts on or near the customer’s site. It ISBN: may also involve delivery of parts to the cus- 0 901 150 401 tomer within a set period of time – for example, parts must arrive at the customer ISBN: 007-144374-6 site within 48 hours from the time of request notification by the customer to the supplier. Customization of product. Involves the mod- Two books work in tandem. ification of product to a form that makes it “Implementing Lead-free Electronics” focuses on actual production, and “Environ- more desirable to the customer. Customiza- ment-Friendly Electronics-Lead Free Technology” covers material properties and technology. tion may involve design, prototyping, manufacturing, testing and other services. Cus- Dr. Hwang’s upcoming Lead-free lectures/seminars: tomization is seen as increasingly important Visit: www.LeadFreeService.com in mainstream manufacturing.8

circuitsassembly.com Circuits Assembly FEBRUARY 2006 27 Focus on Business services. For example, PC firms such as Dell provide benefit obtained can vary greatly from customer to cus- both product and services. Service-oriented PC manu- tomer. However, this attention to the magnitude of cus- facturers provide an array of services such as setup of tomer benefit also permits the possibility for greater prof- operating systems and software, help desk, repair and it. For example, energy service companies (ESCOs) warranty services. The concept focuses on providing provide a package of goods and services to reduce the cost not only a product, but all related and desired services. of energy consumption in large buildings. Typically, the Of special note: the provision of financing or leases by ESCO will provide a range of goods (efficient lighting, many manufacturers. digital control systems and other energy efficient equip- Offer a product as a service. Do not sell the product, ment) and associated services (design, monitoring and rather sell the benefit that the product offers.9 This maintenance). The ESCO takes payment from the sav- approach requires greater attention to pricing, since the ings in energy expenditures that result from the products provided by the ESCO. In some cases, ESCOs have been formed by proponents of the product as a service model.In other cases,firms that manufacture energy efficient equipment have moved into this business, because the model is seen as better for business. If amanufacturing business is not assessing and offering a range of product-related services, opportunities to increase sales, profitability and customer loyalty are probably being overlooked. If services are being offered to customers and the profit margins of the ser- vicesare not higher than the profit margins of associated products, then the value provided to the customer and the pricing of the service should be reevaluated.10 ■

References 1. R. Wise and P. Baumgartner, “Go Downstream: The New Profit Imperative in Manufacturing,” Harvard Busi- ness Review, 5:133-141, 1999. 2. M.R. Leenders and D.L. Blenkhorn, Reverse Marketing, New York: Free Press, 1987. 3. M. Arndt, “Cat Sinks Its Claws Into Services,” Busi- nessWeek, Dec. 5, 2005, 56-59. 4. D. Owen, Copies in Seconds: How a lone inventor and an unknown company created the greatest communication breakthrough since Gutenberg, Simon and Rework & Repair Schuster, 2004. 5. The monopoly position was a result of either patent One product line to exceed your expectations and take care of all your protection or regulated markets. lead-free rework and repair needs. 6. For example, the C-bar chart, often considered a poor cousin to the X-bar R chart, can be of great value in mea- All Chemtronics lead-free products are: suring, monitoring and controlling services that will be Engineered for high temperature lead-free considered in this column at a later date. applications 7. For example, see P. Burrows, “Ever Wonder Why Ink Specifically designed for all lead-free solder Costs So Much?” BusinessWeek, Nov. 14, 2005, 42-44. RoHS compliant 8. Customization is a topic addressed in several literatures CALL NOW! including: manufacturing flexibility, Lean manufacturing and make-to-order. Contact ITW Chemtronics today for more information about the new Lead-Free product 9. M. Michaelis and J.F. Coates, “Creating Integrated Per- line. Call our technical hotline at 770-832-4401, or formance Systems: The Business of the Future,” Tech- email us at [email protected]. nology Analysis & Strategic Management 2:245-250, 1994. 10. If there is further interest in the design of services or Nothing Cleans Like Chemtronics interplay between manufacturing and services, please Soder-Wick®,Flux-Off®, Chemask®, CircuitWorks® and Chemtronics® are advise the author to pursue the topic further in future registered trademarks of ITW Chemtronics. ©2005 All rights reserved. 800-645-5244 / 770-424-4888 • www.chemtronics.com columns. See us at APEX, Booth #1028

28 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Available from AIM SN100C Lead-Free Solder Alloy AIM is pleased to offer the best choice for lead-free wave soldering.

SN100C was developed by Nihon Superior in Japan and offers high-throughput and the lowest cost of ownership as compared to any other lead-free solder alloy. • Does not contain costly silver or bismuth. • Bridge-free and icicle-free soldering. • Smooth, bright, well-formed fillets without micro-cracks. • Low copper pad erosion. • Low drossing. • Good PTH penetration and topside fillet formation. • Does not require a nitrogen atmosphere. • Low aggressiveness to soldering equipment. • Reliable joints (no reported failures in 6 years of field service).

The Bottom Line Customer experience over several years is that the TOTAL cost of running a standard wave soldering machine with SN100C when all factors are taken into account can be up to one third the cost of running the same machine with tin-silver-copper alloys. The actual savings in each case will depend on the number of factors that apply, but the cost of running a line with SN100C is always lower than the cost of running the same line with tin-silver-copper. Please contact AIM for additional information.

Manufacturing & Distribution Worldwide USA +1-401-463-5605 Canada +1-514-494-2000 Mexico +52-656-630-0032 Asia-Pacific +852-2649-7183 [email protected]@aimsolder.com ·· www.aimsolder.comwww.aimsolder.com ·· www.leadfree.comwww.leadfree.com Global Sourcing Killing Business A post mortem of opportunities lost by internal mistakes.

tisdefinitely busy out there! Most How many future prospects do you think OEMs and EMS companies, it seems, I will refer to the companies that fail to I have been going gangbusters for the reward my efforts? Word-of-mouth refer- past six to eight months.But more business rals are priceless, but you should pay for does not necessarily mean better levels of them anyway. customer service. In fact, many companies DOA no. 3: Death by delay. Some compa- deal a death blow to their long-term nies take far too long to turn around prospects by letting service slide just as quotes, or fail to inform customers as their sales graphs start going up. early as possible about unavoidable Is your company killing business? Cus- delays. If you need to hire additional staff tomers expect their concerns to be heed- to handle the needs of your customers ed, and their problems to be solved. and prospects quickly and efficiently, do Ignoring this reality is like killing the cash not hesitate to do so. Otherwise, you may cow. Certainly, no one dies from an unre- find your company has too much time on turned phone call, a slipshod quote or a its hands. botched board delivery. But too many of DOA no. 4: Failure to follow up. Many firms those things can terminate your trade. I disregard the details that will keep a cus- am amazed at all the “bodies” I see in the tomer coming back. Does your company PCB industry, businesses destroyed by check up on prospects and customers, suicidal behavior. gauge their feelings and query them on Here are a few of the chalk-line cases quality issues? Do you have corporate Ihaveseenlately: paramedics who can be first on the scene DOA no. 1: Fumbling with the formalities. when the customer needs them? Are the The buyer at a well-known high-tech aches and pains of contract manufacturing OEM said he waited more than three diagnosed properly (via corrective actions) weeks just to get a nondisclosure agree- and an appropriate remedy carried out? ment signed from a prominent EMS firm If you recognize your own company in before he could give out an RFQ. Unwill- any of the aforementioned life-threaten- ing to wait any longer, the buyer found ing situations, the business you are killing another, more responsive, assembler. Your may be your own. company should have a rapid-response You can still revive the patient. It does process in place to send out an NDA, a not take a brain surgeon to devise a win- brochure with company information and ning bedside manner and the treatment a welcome letter to new prospects at a plan needed to keep your prospects moment’s notice. healthy and happy. It just takes a staff that DOA no. 2: Refusing to play the referral is dedicated (from the top down) to game. Occasionally I come across a pro- maintaining your company’s most impor- ject that is not a good fit for my company. tant asset – the customer. ■ In that case, I will recommend another company better suited to the job, and, having already performed the triage on this case, I will request a consulting fee. Greg Papandrew is founder The shortsighted companies will throw and president of Bare Board up a wall of bureaucracy, muttering about Group (bareboard.com), a dis- contracts and local sales reps (the same tributor of offshore-manufac- reps who have failed to contact the tured circuit boards; greg@ prospective customer). Surely, something bareboard.com. His column can be worked out that benefits everyone. appears quarterly.

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onvergence! We keep hearing about product faces to inject nanoparticles into the cells. The MEMS convergence as if it were the next big thing. chip is a nanoparticle manipulator with a water-repel- C Truth is, product convergence has been around lent diaphragm consisting of numerous micro dishes for at least a century, and probably for millennia. Many arranged in a lattice format. The cell interaction princi- products, like the clock radio, are simple combinations ple was verified in an experiment using a water droplet of two mature products. The latest cellphones can containing yeast cells and silica nanoparticles. receive Internet messages, download and play music, Toshiba is investigating combinations of various create, store, receive and send photos, and maybe even nanomaterials and physical energy levels from the tune in TV. MEMS chip, hoping to develop a novel non-chemical Although less is said about technology convergence, technique for targeting specific cells. Optimization of this is also a dynamic and exciting area. In the past, we the MEMS structure for a specific type of cell may be have combined closely allied technical areas such as possible since the mechanical drive can be miniatur- audio and video. This old tech duo continues to be the ized down to a few square microns. Nanoparticles for basis for new consumer products. Not much has been targets other than cells are also being investigated. revealed about merging dissimilar fields, however. But Applications could include biological investigative today, discoveries are made at the crossroads of diverse tools for studying the reaction of cells to physical scientific fields and products are born at the intersects effects and examining their detailed functions. Bio- of technology. nano-MEMS should find medical applications in the Microelectromechanical systems (MEMS) and nan- future. Perhaps cancer cells will selectively absorb cer- otechnology are certainly two of the top 10 technologies tain nanoparticles, “or nano bullets,” manipulated by for 2006 and biotech is advancing at an accelerating the appropriate MEMS vibrations. pace to gain recognition, as the secrets of DNA are We may safely assume that bio-nano-MEMS repre- unraveled through genome projects and related studies. sents an emerging technological area that will bring These three important areas are ripe for technology important breakthroughs. But moving these devices convergence. MEMS chips can be made at just the right from the lab into the realm of commercial development scale for interaction with biological systems, especially will present a new set of challenges. The first issue: cells, and devices have been built to manipulate and packaging. We have become so accustomed to the rela- even “operate” on cells. Nanoparticles are small enough tively simple requirements for the electronic package to be handled and even pumped by MEMS chips mak- that it is difficult to imagine dealing with more than just ing bio-nano-MEMS a natural combination. The merg- piping electrons and shutting out the environment. But ing of bio, nano and MEMS appears to be a magic mix the new breed of chips deals with electrons, mechanics, of science and technology that can generate synergy to materials and more. yield unusual results and valuable new devices. Imagine creating a package that protects a sophis- Although many universities are deeply engaged in ticated electromechanical chip and its electrical inter- research involving biotech, nanotechnology and connects while allowing the entry of biological fluids. MEMS, several electronics giants (IBM, Philips, ST- Packaging for this field will require more complex Micro) and many Japanese powerhouses have been and precise enclosures with fluid channels. The good actively pursuing these three fields. Researchers work- news is that methods such as microinjection molding ing on combining these areas into a new technology could produce such products, but if even finer fea- Dr. Ken Gilleo is triad have provided interesting bits and pieces of news tures are required, emerging nano-imprinting might with ET-Trends LLC; over the past year or two, but a recent release from be applicable. [email protected]. Toshiba is worthy of a closer look. Will there be more tech mergers in the future? His column appears Toshiba has developed nano-manipulation technol- Absolutely! Photonics is high on the list and already part four times a year. ogy that can inject nanoparticles into living cells and of commercial optical-MEMS products. So stay tuned, ultimately induce specific reactions. These MEMS as we get closer to fabricating the world on a chip. ■ devices generate subtle vibrations that bond nanoparticles onto cellular surfaces, and the system can operate Ed.: Please see Gilleo’s new book, MEMS/MOEMS Packaging, published by on many cells simultaneously. Vibration produced by McGraw-Hill in November 2005. the MEMS diaphragm causes nanoparticles in a fluid to first attach to cell surfaces. Next, the vibration generates thermal energy that physically alters the cellular sur-

32 Circuits Assembly FEBRUARY 2006 circuitsassembly.com

Screen Printing Z-Axis PCB Support Options Custom solution or universal support system? There’s an option for everyone.

ne overlooked factor in solder paste printing side component can also damage that component. Sup- optimization is z-axis board support.This means port pins can be used for single-sided or topside support. O supporting the bottom of the board during Offline manual grid pin systems. An offline grid pin sys- printing. Customers often experience less-than-opti- temprovides pins placed in a grid pattern and is set up mumresults because they overlook z-axis board support. offline for the next board to be printed.Pins are placed on The rule of thumb for squeegee blade pressure is 0.45 the grid to provide support without contacting bottom- to 0.68 kg of pressure per 39.37 mm of squeegee blade.For side components.Again,ensure that pins are placed in the example, a 472.4 mm squeegee blade will apply 5.45 to correct location; a visual aid or instructions are required 8.18 kg of force on the board during printing. The down- for the operator. A customer will usually have at least two ward force of the squeegee blade will deflect the circuit grid pin systems, one for the board being built and the board to some degree depending on the board’s size, other being set up for the next board to be built. thickness and, most importantly, the amount of support Automatic conformal systems. These systems are usual- under the board. ly pneumatically activated 39.37 x 590.6 mm “blocks” Thinner, larger boards deflect more. The deflection with two rows of pins spaced about 39.37 mm apart. The of the PCB during the print cycle will eliminate the gas- required number of blocks are placed in the work nest keting (sealing) of the PCB pad to the stencil aperture. parallel to each other with a predetermined gap between Gasketing the board pad to the stencil aperture ensures to support the width of the board being built. When the that the paste being printed does not get under the sten- board is in position the pins are activated. They rise to cil, where it can cause wet bridges that often turn into the lowest point they contact, conforming to the topog- solder shorts after reflow. raphy of the bottom-side component layout. The sup- Anumber of options are available to support a PCB in port pins have a soft compliant cap, permitting contact the z-axis during printing. If the board is a single-sided with bottom-side mounted components. Once raised to assembly or the first side of a double-sided assembly, the board height, the pins lock into place and support each entire bottom side is available for support. Flat plates or board as it is processed. These systems can be set up magnetically mounted blocks are ideal in this instance. based on a golden board or activated for each individual When printing the second side of a double-sided board. The systems are also used for board support in assembly, consider how to support as much of the placement equipment. board as possible without disturbing or damaging bot- Gel tooling. This proprietary tooling is a soft pliable tom-side components. Several options are available: “bag” of gel material mounted in a metal housing with a Custom tooling (also called dedicated workholders). magnetic base to hold the tool in place. The gel material Custom tooling is made for a specific assembly or a conforms to the bottom-side component layout and family of very similar assemblies. The tool provides gently supports the board. Displacement is greater in the clearance for bottom-side components while providing z-axis than in the x- or y-axes, so it can support individ- support in the areas of the board that do not have com- ual components without sacrificing support for adjacent ponents mounted. Custom tooling provides maximum components. Provided sufficient gel blocks are used to support without contacting any of the bottom-side cover the area, it is virtually impossible to place them Joe Belmonte is mounted components. The issues with custom tooling incorrectly because they provide support without dam- project manager, are cost and managing board revision levels. When used aging bottom-side components. Such tooling is also advanced process in high volume operations, custom tooling is reason- used for board support in placement equipment. development, at ably cost effective. To address revision levels, customers Automatic pin placement systems. Some printers have Speedline Technologies must either replace the tooling once that assembly or patented systems that automatically place support pins (speedlinetech.com); family of assemblies is no longer built, or make com- at programmed locations. The support pins are usually jbelmonte@speedline promises in the design of the top plate to permit multi- housed in a tray or carousel and picked and placed by tech.com. His column ple revision levels to run on the same tool. the machine using data specific to the board being built. appears semimonthly. Support pins. Support pins provide a flexible board This system provides the flexibility of support pins support system. Usually, a magnetic base holds them in without the problem of misplaced support pins as the position. An operator then places them in position. Pins program controls pin location. must be placed correctly to provide maximum support Universal shape memory board support system. This sys- and also to ensure they do not contact a bottom-side tem is a 708.7 mm long “bladder” that contains solid component. If a misplaced support pin contacts a bot- particles. Once the bladder is conformed using a golden tom-side component, the board and stencil will not be board, a vacuum locks the solid particles without parallel, resulting in many defects. Contacting a bottom- shrinkage, creating a firm, precise support. ■

34 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Who Says Lead-Free Is Dull? Kester’s EnviroMark 907 Bright Solder Joints and a Whole Lot More

Kester’s EM907 No-Clean Lead-Free Solder Paste is designed to exceed customers’ expectations for high yield lead-free manufacturing. EM907 is a newly engineered product speciﬁcally for the high thermal demands of assembling with lead-free alloys such as the family of SnAgCu (SAC).

• Lead-free joints that are cosmetically bright as SnPb joints • Excellent solderability to a wide variety of board and component EM907 Solder Joint surface metallizations • Maintains excellent print quality at high print speeds up to 6 in/sec (150 mm/sec) • Extended printing downtimes and long stencil life • Anti-slumping to eliminate bridging and micro-solderball potential • Excellent printing characteristics to 16 and 20 mils pitch (0.4 and 0.5 mm) • Prints down to 0201 pad sites • Light colored residue • Designed for air reﬂow as well as nitrogen Typical Lead-Free Solder Joint • J-STD-004 Flux Classiﬁcation ROL0

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For additional information: visit www.kester.com call 800-2-KESTER fax 847-390-9338 Better Manufacturing Reflow Profiling: Do It Right Sure, it is a monotonous procedure, but no single profile can do it all.

“Fat, drunk and stupid is no way to go through life.” – Not that complex, is it? That said, it is surprising Dean Wormer, Animal House how many people do not indulge in the practice. I am not quite sure how they determine proper oven settings t amazes me how many people do not know how to without profiling (osmosis? laying hands across the profile a reflow oven. Come on, gang: we have been oven? psychic telepathy?). Some oven salespersons still I reflow soldering for over 25 years now (time flies tout the “one profile does all” line. (If you buy that, I when you are having a good time). Yet many people still have a bridge I would like to show you.) Profiling each do not have their act together. It is true: No single pro- application is necessary but not all that difficult. Of file can do it all. Trying to make do with a single profile course there is a downside: reflow profiling is a monot- is going to bite you in your assets when Pb-free manu- onous procedure. Reflowing in a convection oven is facturing comes home to roost. unexciting. With printing and component placement, at Profiling is the process of determining the proper least there are the dynamics of mechanical motion. In time/temperature durations a PCB assembly must sus- reflow, the assembly disappears down a dark tunnel and tain throughout the reflow cycle.1 These are dictated by emerges about four minutes later. One oven manufac- solder paste characteristics such as solder alloy, solder turer once experimented with cameras to observe the sphere size, metal content of the paste and chemistry. melting of the solder. And some vapor-phase machines The setpoints of the emitters and conveyor speed set- have windows in the reflow zone. Now that is entertain- ting of the oven required for reflow are affected by the ment! (Inline cleaners have windows so this exciting mass, surface geometry complexity and substrate con- process can be observed, too. What’s next, a reality tele- ductivity of a particular assembly, plus the oven’s capa- vision show on soldering?) The point is, you want to bility to impart sufficient heat energy. The oven’s heat optimize the profiling procedure to minimize the time transfer efficiency and the operator’s experience will spent on this exhilarating task. determine just how much of the profiling process is an Most important is proper attachment of thermocou- exercise in trial-and-error. ple to assembly. Do not use Kapton tape: It will not Reflow soldering is not just “the board goes in the make consistent contact with the solder joint that you oven, heats up, the solder melts, the board comes out, the think is being monitored. Instead, what is likely being solder cools.” But, it is not rocket science, either. The measured is a combination of air temperature, tape time/temperature duration information is supplied by temperature and sometimes (maybe) joint tempera- the paste manufacturer for the specific formulation being ture, with the latter highly inaccurate. The proper used and can, hopefully, be found on the datasheet.2 Typ- method is to attach TCs with either a high temperature ically, for SnPb37 or SnPb36Ag2 the full liquidus or solder alloy or a conductive epoxy. This may mean sac- reflow temperature will be a minimum of 205° to 210°C. rificing an assembly to the profile gods, but you will For the Pb-free SAC305 alloy, the minimum temperature have a tool with which periodic checks may be per- to be attained at peak is around 235°C.3 Again,look to the formed on the accuracy and repeatability of the profile Phil Zarrow is datasheet for the temperatures specified by the manufac- for that board in your oven. For very low quantities and president and SMT turer; it is their formulation in terms of metallurgy and a high mix of boards, a number of nondestructive, process consultant chemistry (flux, solvents, etc.). reusable contacting probes are available. with ITM Consulting The maximum temperature the assembly can see is Useanassembly that is populated with compo- (itmconsulting.org); dictated by the component (or material) on the assem- nents as it will be passing through the oven. Except itmconsulting@aol. bly with the lowest thermal threshold of pain. Subtract when reflow soldering a bare board, do not profile com. He still bears the a “buffer” of 5°C from this temperature to determine using an unpopulated board. TCs will be attached at scars, physical and the temperature of the most vulnerable component interconnections (lead-to-pad junctions) that repre- mental, of reflowing (MVC). The maximum gradient across the assembly is sent, at least, the warmest and coolest points on the convection/IR ovens. defined by subtracting from the MVC value the tem- board. The warmest point will typically be a low-mass perature at which the liquidicity of the molten alloy is component (such as a passive) located near a corner ideal for wetting (full liquidus temperature) which is or edge of the board. The coolest point will likely be usually 15° to 20°C above the melting point of the sol- an interconnect of a high-mass component (QFP, der alloy (which you conveniently obtained from the PLCC, BGA) near the center of the board. Place other solder paste manufacturer’s comprehensive datasheet). TCsatheat-sensitive components (i.e., the MVC) and Do not forget to attain the shortest time above liquidus other high-mass components to ensure they get suffi- temperature, too. cient heat.

36 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Better Manufacturing

When using a previously soldered M.O.L.E., Datapaq) that travels through assembly, remove the solder from inter- the oven with the test assembly and connects to which TCs will be attached. records the temperature from multiple As the board was likely soldered with TCsatprogrammable time intervals. SnPb37 and you will be using, perhaps, These systems are offered as “run-down- SnPb12, if you simply solder the thermo- load-read” or as transmitting units that couple with the latter, you would wind up permit observation of the profile in real- with a “mystery” alloy – one that will not time. Over the past few years, these sys- sustain multiple thermal excursions tems have improved in accuracy and ease required of the test board. Regardless of of use, with more sophisticated software. what is covering it, the underlying Capable, accurate profile prediction SnPb37 will reflow at its usual tempera- capability has taken almost all the guess- ture and undermine the durability of the work out of profiling for most applica- attachment. It is therefore mandatory that tions. This feature saves time in a way the existing solder be removed using sol- that is nothing short of miraculous. der-wick. This should also be done if con- Another excuse for not profiling every ductive adhesive is used to attach the TC. application eradicated. Otherwise, the SnPb37 will reflow under- Today’s ovens are powerful in terms of neath the adhesive. heat transfer efficiency; this translates to Profiling is tedious; nothing is worse greater ease of profiling and less profiles than losing a TC during a run and having required among similar boards. Just ask to do it over again. Hence, removing some grizzled veteran from the infrared excess solder is very important. I have an and convection/infrared reflow days (the assembly that I use for evaluating reflow pre-convection-dominant era) about the systems that was instrumented in this tedium of endeavor profiling. A relatively fashion. This assembly has seen at least easy assembly might have taken five pass- 150 reflow cycles and has never lost a TC es while a moderately complex applica- attachment. The rest of the board does tion could take a day to profile. Today, it is not look too hot but the TCs are intact. fun and easy – well, it is not really fun. But After removing old solder, apply a small it is relatively straightforward. Care in the amount of flux and then, using a solder- profiling process can save time and ing iron, add a small but sufficient improve accuracy. All that time saved can amount of the high-temperature solder. be spent on your RoHS compliance While SnPb12 will work when profiling efforts. Are we having fun yet? Pb-free alloys, consider the conductive Remember, we’re all in this together. ■ epoxy route for attaching TCs to Pb-free applications. End Notes Use Type K, 30 AWG TC wires, preferably pre-welded. After attachment, route 1. Not to be confused with efforts by airlines or the FBI. the TC leads toward the rear (in terms of 2. Some manufacturers do supply peak reflow tempera- direction of travel) of the assembly. Some ture (full liquidus temperature) and preflow soak tem- people prefer to terminate the TC lead at perature and maximum duration information on prod- the trailing edge of the PCB with a con- uct data sheets. Otherwise, a call should be made to nector. The lead from the measuring the manufacturer. If a person who can supply this info device can then be quickly connected cannot be located at the solder paste vendor, it is time and disconnected. Use Kapton tape to to find a new supplier. provide hold-down and strain relief to 3. There is active experimentation underway to determine the TC leads at appropriate locations on if a lower full liquidus temperature might be feasible. the PCB. Stay tuned. Most reflow machines are equipped with on-board profiling software. This permits TC leads to be plugged into ports on the oven and tracked in real- time on the system monitor. Many people prefer a data-recorder device (KIC,

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Full Disclosure

Michael Kirschner

substances, including oxides and other com- It’s not just about the ‘RoHS Six’; it’s the pounds for the four metals. PBBs and PBDEs are classes of brominated flame-retardants, each con- compounds that contain them. taining many specific compounds. You are not looking for just the RoHS Six; you are looking for hat do you make parts out of? Getting a compounds that contain them. Exemptions are quick and straight answer to this seem- available for certain uses of some of these materi- W ingly simple question continues to be a als, including the use of Pb in glass or ceramic. critical and complicated step in the race to com- Dozens of Pb-based compounds are used in elec- ply with RoHS and WEEE. A lack of standards tronics, as well as several cadmium- or mercury- and understanding among all parties including based compounds, and a few hexavalent chromi- OEMs, service providers, distributors and com- um compounds as well. The actual number of ponent manufacturers, coupled with a blizzard of materials to look for is closer to 100. requests in a multitude of formats, is conspiring Second, material compliance is not the end. to change the landscape of material declaration, While many manufacturers are successfully just months before the European Union’s RoHS reflowing SAC alloys at 240°C or so, this is still laws go into effect. higher than the 230°C many electronics are How is an OEM supposed to accomplish due designed to withstand. This really becomes an diligence in this environment? Many pitfalls exist, issue with connectors, LEDs, optocouplers and not the least of which is understanding what to other devices that use plastics that can melt at the ask for and why. Here, we answer that question. elevated temperatures SAC alloys require. Major issues in assessing component compli- Third, many OEMs and service providers are ance include: so focused on the RoHS directive that they, as well •Material compliance with RoHS. as the component manufacturers and suppliers, •Thermal compliance with higher reflow and forget the material requirements spelled out in wave solder temperatures where SAC (tin-sil- WEEE. In particular, Annex II calls out several ver-copper) alloys replace SnPb. material classes and substances not defined else- •Collecting the right data to enable compliance where – and often overlooked. Combined with with the various EU states’ implementation of Article 11, paragraph 1, there is a reporting the WEEE directive. requirement that goes beyond the RoHS Six for •Supporting the OEM customer’s additional WEEE. Several EU member states, such as Austria material restrictions and requirements. and the U.K., further define “dangerous sub- •The “virtue” of standardization. stances and preparations” to include those defined Let’s address each of these issues. First, there in Annex 1 of directive 67/548/EEC (as updated by are six classes of materials defined in RoHS. Not 2001/59/EC). Service providers that do not collect six substances; six classes. Each class has multiple these materials (which include and go well beyond

40 Circuits Assembly FEBRUARY 2006 circuitsassembly.com ADVERTISEMENT /HDG)UHH 1HZ3UREOHPV1HZ6ROXWLRQV

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JIG-101’s requirements) on behalf of OEM customers are doing Also, make sure the CofC is signed by a corporate executive, them a serious disservice. When using a service provider to collect preferably with fiduciary responsibility. Finally, be sure you data, make sure they know what they are doing and know what understand why you are getting a CofC rather than direct evi- you need better than you … not all do. dence that your supplier knows what their product is composed Furthermore, make sure that any supplier that provides a of. The answers may surprise and scare you. “Certificate of Compliance” (CofC) is also covering the specific Fourth, what if you cannot get material data from your sup- information WEEE and the various EU countries require, such as pliers? What do you do? Lots of companies are screening using any brominated flame retardant, not just PBBs and PBDEs, in all products like handheld x-ray fluorescence (XRF) technology plastics including IC mold compounds or connector bodies. and thinking that is enough due diligence. It will not be. Run as fast as you can from those suppliers and find new ones. If they cannot tell you what their product is made of and how those materials are controlled lot-to-lot, then youdonot want them as a supplier. Some people have forgotten the past 20 years of supplier management best practices: trust through verification, not screening. We have been through screening hell and successfully pushed the responsibility for quality back on the supply base. Is this any different? Yes, RoHS is a new requirement; but why would we think that it is therefore out of control? The industry is now at the “guarantee,” not “test,” level of supplier management. Drive that level of expectation with your supply base. XRF does have its place, but only in very Aqueous Technologies has received more prestigious limited circumstances. Those are mainly industry awards than all other cleaning equipment inventory management for distribution, companies combined. and contract manufacturing, where the For post-reflow defluxing, stencil cleaning, and cleanliness testing products, choose the winner... Choose Aqueous Technologies. ability to tell quickly whether a part has lead on the termination (rather than precise, Aqueous Technologies SMT Series accurate knowledge of its ppm level) is automatic de-fluxing systems are the important. Outside these applications, industry s most popular batch-format handheld XRF lacks accuracy and requires cleaners. Wash, rinse, cleanliness test, too much sample preparation (and exper- and dry functions are conducted auto- tise in that preparation) and expertise in matically, without operator interaction. operation and interpretation to be a useful Simply enter a few parameters including due diligence tool for the majority of electronics OEMs or even component suppli- desired cleanliness level and the machine ers. Using it as a defense strategy could be does the rest. A built-in recycler filters shot down in a court of law – and fast – if and reuses wash solution for maximum this is not well understood. efficiency and environmental safety. Fifth, there are additional requirements The patent pending Focus-Wash spray technology ensures cleanliness from the likes of IBM, HP, Nokia, the big even on ultra-dense SMT assemblies. Nine models to choose from Japanese OEMs that subscribe to the Japan- including the SMT1000 Series Lead-Free De-Fluxing Systems. ese Green Procurement Survey Standard- ization Initiative, and the attempt at unify- www.AqueousTechnologies.com ing them all, the Joint Industry Guide: JIG-101. If you collect only JIG-101 data, you risk not collecting data your specific customer needs as well as information for future needs. Ensure that you and your data Aqueous Technologies Corporation 9055 Rancho Park Court Rancho Cucamonga, CA 91730 USA services provider understand exactly what +1 909.944.7771 Fax +1 909.944.7775 [email protected] requirements are supposed to be met.

42 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Material Declaration

And finally, can we standardize this mess? Will IPC-1752’s from component manufacturers, go after what we know and definition of an XML standard help? Will the PDF form that apply our best technical guess as to what is intended based on all implements it help? Answer: probably. But it is no panacea. the definitions and hints issued over the past few years. The best The GIGO principle is in full effect here: garbage in, garbage we can do for the future is get in front of this as an industry, and out. If the level of understanding at either the requestor or get deeply immersed in discussions and development of this sort component manufacturer is inaccurate, the data will likely be of legislation with governments around the world. There are inadequate. plenty of good reasons to design products in an environmental- Plenty of consternation remains about just what is a ly sound manner; if the industry involves itself in the process, it “homogeneous material,” for instance. The EU has failed to will also be done more easily, sensibly, profitably and to greater come up with a definition that will satisfy everyone. Neverthe- effect than if legislators and NGOs do it alone. ■ less, what the EU is trying to achieve is clear: elimination of these materials from electronics. So whether a mold compound Michael Kirschner is president of Design Chain Associates LLC (design- for a PLCC device is actually a truly homogeneous material or chainassociates.com), a consulting firm focused on helping electronics OEMs not (most of the time it is not), and whether it is possible – comply with RoHS/WEEE requirements; [email protected]. even for a really tiny person with a really tiny file – to scrape back each of thousands of layers of ceramic and thousands of layers of conductor to separate the materials in a multilayer ceramic capacitor, is not the point. We view this definition as a theoretical thought experiment: it is not intended to define a practical way to determine what materials comprise a component. It defines a practical way to identify excessive concentra- tions of banned materials. Reporting requirements will only become more extensive. At this stage, the best we can do is insist on full disclosure (to the extent feasible that also stays clear of proprietary information)

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circuitsassembly.com Circuits Assembly FEBRUARY 2006 43 Pb-Free Printing Parameters

Understanding Pb-Free Stencil Requirements

Clive Ashmore

so, we manually programmed the automatic Overprinting the pad aids the assembly stencil printer with offset values, which moves the alignment of stencil to board by the pre- process, and could balance wetting scribed amount; this value can be adjusted in 1 µm steps. To understand the influence aperture forces during reflow. designs and offsets have on Pb-free assembly, we have included a stencil which has many aperture b-free materials differ from Pb-rich mate- geometries. rials in aspects such as self-centering capa- Astencil was fabricated from a Ni-formed P bility and wetting characteristics. These blank. (Nickel was chosen due to benefits estab- differences beg more questions regarding aperture lished from earlier work.) Apertures were cut design and assembly defects. This article address- viaaYAG laser. The stencil had a full range of es those, and examines what happens when the aperture designs fabricated into the artwork process window is intentionally violated. (Table 1). Process window. The experiment focuses on The purpose of varying the apertures within violating the print process window and measur- the stencil was to determine if certain apertures ing the response. This was achieved by including would influence the quality of SMT production. x and y offsets to the solder paste deposits. To do In addition, we could determine if aperture geometry would increase the process window for Table 1. Key of Aperture Designs Pb-free assembly. Aperture Design Color Code Shape Icon Solder paste printing for the experiment was A Standard rectangular conducted using a 125 µm-thick nickel laser-cut stencil. A thinner 100-µm stencil would provide

BRounded corner better solder paste release for smaller devices, but would inherently reduce the solder paste volume available for larger component types. A 150 µm- CRounded corner thick stencil would have unacceptable solder paste transfer for smaller apertures. D Home plate The apertures were neither microetched nor surface finished. The metal mask was mounted in

E Inverted “V” a center-justified configuration. One stencil was designed for the experiment; the passive component artwork on this stencil was broken into sub FOffset designs, which provided a total of 67 designs. Breakdowns of these designs are shown in Figure

44 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Pb-Free Printing Parameters

Table 2. Key of Aperture Measurements X (1:1) Component Aperture Aperture Aperture Type Width (A) Space (B) Length (C) 1206 1.778 1.397 4.191 805 1.397 0.889 2.921 604 0.889 0.762 2.286 402 0.558 0.508 1.676 201 0.381 0.228 0.838 0.65 mm QFP 2.54 0.65 0.394 PLCC 2.07 1.27 0.8 0.65 SOIC 1.905 0.65 0.381

Y (Standard specification) Component Aperture Aperture Aperture Type Width (A) Space (B) Length (C) 1206 1.678 1.397 4.091 805 1.297 0.889 2.821 604 0.789 0.762 2.186 402 0.458 0.508 1.576 201 0.281 0.228 0.738 0.65 mm QFP 2.44 0.65 0.294 PLCC 1.97 1.27 0.7 0.65 SOIC 1.805 0.65 0.281

Z (Overprint) Component Aperture Aperture Aperture Type Width (A) Space (B) Length (C) 1206 1.878 1.397 4.291 805 1.497 0.889 3.021 604 0.989 0.762 2.386 402 0.658 0.508 1.776 201 0.481 0.228 0.938 0.65 mm QFP 2.64 0.65 0.494 PLCC 2.17 1.27 0.9 0.65 SOIC 2.005 0.65 0.481

1 and Table 2,with the board split into sections A and B. Aper- FIGURE 1: Map of aperture designs (top), with Section A (middle) and ture designs are labeled A to F and aperture sizes X to Z to help Section B (bottom) enlarged. tabulate the results. Test board. The test vehicle (Figure 3) was a double-sided panel measuring 140 x 204 mm. Attachment pad metallurgy was Chip component orientation Reference offset movement bare copper covered by Entek+ (OSP). Passive components included 0201, 0402, 0603, 0805 and 1206. Pad widths, lengths A + Y and spacing are documented in Table 3. Print platform. The study was conducted using a DEK Europa platform that was calibrated mechanically. Using the manufacturer’s defined procedure, Cp and Cpk values were verified to C B pass the minimum 1.6 values. To reduce statistical noise, the -X + X same machine, interface and transfer heads were used throughout the experiment. The same batch of substrates was also used for measurement purposes. These printer process parameters were used throughout the -Y experiment: •Print speed = 80 mm/s. •Print head = 300 mm cassette. FIGURE 2: Attachment pad dimensioning.

circuitsassembly.com Circuits Assembly FEBRUARY 2006 45 TM CoolCap

Introducing ALPHA® CoolCap™ and CoolShield™ ® Devices – The most effective solution for preventing partial reflow and damage to adjacent components during rework. You work hard to ensure all rework procedures minimize problems with adjacent components. Let CoolCap™ and CoolShield™ devices work hard for you. Keep BGAs, QFPs, and other heat sensitive devices well below reflow temperatures, for both Tin-Lead and Lead-Free rework. ALPHA CoolCap Rework Kit Applications: • ALPHA CoolCaps™ fit completely over standard size BGA and QFP packages. • ALPHA CoolShields™ fit beside heat sensitive components like electrolytics and small passives. Availability: • BGA Rework Kit – 30 CoolCap™ devices fit common size BGA devices. Nine CoolShield™ devices in three standard lengths. • QFP Rework KIT – 33 CoolCap™ devices fit common size QFP alpha devices. Six CoolShield™ devices in three standard lengths. GO TO www.newalphaproducts.com for more information Or, contact your Cookson Electronics representative.

Worldwide Headquarters • 600 Route 440 • Jersey City, NJ 07304 • USA • +1-800-367-5460 • www.alphametals.com European Headquarters • Forsyth Road • Sheerwater • Woking GU215RZ • United Kingdom • +44-1483-758-400 Asia-Pacific Headquarters • 1/F, Block A • 21 Tung Yuen Street • Yau Tong Bay • Kowloon, Hong Kong • +852-3190-3100 Pb-Free Printing Parameters Cookson Electronics SMT Material

•Paste pressure = 1.8 bar. were tombstones. Figure 7 illustrates Technologies •Print gap = 0 mm. results from this setup. •Separation speed = 10 mm/sec. The next step in the experiment was to Both x and y print offsets were includ- maintain the 140 µm y offset without ed, to give insight to the robustness of a nitrogen and permit the reflow process to Pb-free print process. (Table 4 lists the run in air. The result was remarkable; level of offsets for all the runs.) defects were noticeably reduced to 279. Solder paste. The solder paste sample Figure 8 shows these results. used is shown in Table 5. The material was The final batch of tests increased the suspended in a no-clean flux medium. offsets to 280 µm. Again the y offset shift Reflow. The boards were reflowed was more responsive and gave a total of using a standard 10-zone oven. The board 1,505 defects. Figure 9 illustrates the was profiled to ensure a correct preheat, results observed during this setup. This soak and peak setup. Figure 4 shows the set of photographs shows the reasonably Our SMT material technologies are reflow profile used; additional informa- good reflow results, which were obtained part of the world’s most complete tion about the oven setup is below: from the bottom row of 0201 compo- line of lead-free solutions. Their •Oven model: Vitronics-Soltec XPM2 nents (the aperture design which corre- proven compatibility helps you •No. of heating zones: 8 sponds to this row was AZ). The other transition to lead-free processes •No. of cooling zones: 2 two rows were the same shape but differ- seamlessly. •Convection fan speed: 3500 rpm ent aperture size; the poorer response can •Oxygen level when nitrogen active: be seen clearly. • ALPHA® OM-338 Solder Paste – <50 ppm The 280 µm offset in the x axis was not excellent print consistency, •Conveyer speed: 53 cm/min. as responsive, but this test did result in wide process window, low •Peak temp.: 240°C 300 defects. Figure 10 illustrates the voiding ® Nitrogen was used for a selected num- results of this setup. • ALPHA OM-325 Solder Paste – ber of runs (Table 4). As seen in Figure 5, print processes µ fine feature printing down to 0402mm components, ultra in which the offsets do not deviate high soak up to 180-190°C Results could be guaranteed, “no change” to • ALPHA® Stencils – lead-free A recap of the factors included within stencil architecture is required. But we optimized design rules for this experiment: know that FR-4 has a dimensional sta- accuracy and consistency • 67 individual aperture designs for each bility of no greater than 0.08%, which • ALPHA® Telecore Plus Cored passive component. would in the case of this test vehicle Wire – complete lead-free • Offset shift in both x and y. have potential excess of 200 µm offset. compatibility, activated rosin, •Atmosphere of air and nitrogen. Therefore, tests conducted at 140 µm halide-free flux core, non- The first setup focused on the effects will be further analyzed because these corrosive residues of a standard process. During this setup results reflect real life. no adjustments such as offsets were Figure 11 shows a breakdown of the GO TO included, and the reflow atmosphere was defects by aperture design. We focus only www.newalphaproducts.com nitrogen-enriched. The results from this on the runs in which the 140 µm offsets for more information batch of experiments showed that with a were included. It is interesting to observe Or, contact your Cookson centered print process the assembly was the effects of 280 µm offset (but when Electronics representative. extremely robust. The next batch of running with this amount of alignment results shows the assembly yield when x offset Pb-free implementation would be Americas + 1-800-367-5460 and y offsets are included. the least of your worries). Figure 11 also Europe + 44-1483-758-400 Figure 5 shows that a shift of +ve 140 shows that adding nitrogen has a detri- Asia + 852-3190-3100 µm in the x axis with nitrogen does not mental effect on the process. www.cooksonelectronics.com cause a large number of defects (four). The results, which used air within the The photographs show the top left corner reflow process, show superior capability, of the 0201 chips, this includes aperture but certain aperture designs still show designs A at 1:1 (x), standard spec (y) and issues when 140 µm offsets are used. overprint (z). Figure 6 illustrates results Aperture design AZ shows good capabili- observed during this setup. ty and is interdependent of the reflow When the same +ve 140 µm offset is atmosphere (AZ, a standard rectangle and added to the y axis, 576 defects were overprint). This would be the preferred observed. The majority of these defects design for all passive components, as it alpha

circuitsassembly.com Pb-Free Printing Parameters

Table 4. Log of Print Offsets from Each Run Print Material Side D / B Print Print Reflow Direction Offset Atmos. Part A

1A OTHC Dummy Fwd 0 N2

2A OTHC Dummy Rev 0 N2

3A OTHC Build Fwd 0 N2

4A OTHC Dummy Fwd 0 N2

5A OTHC Dummy Rev 0 N2

6A OTHC Build Fwd 0 N2

7A OTHC Dummy Rev 0 N2

8A OTHC Dummy Fwd 0 N2

9A OTHC Build Rev +140 µm (x) N2

10 A OTHC Dummy Fwd +140 µm (x) N2 11 A OTHC Dummy Rev +140 µm (x) N FIGURE 3: Photograph of test board. 2

12 A OTHC Build Fwd +280 µm (x) N2

Table 3. Pad Geometries 13 A OTHC Dummy Rev +280 µm (x) N2

Component Type Pad Width (A) Pad Space (B) Pad Length (C) 14 A OTHC Dummy Fwd +280 µm (x) N2

1206 1.778 1.397 4.191 15 A OTHC Build Rev +140 um (y) N2

0805 1.397 0.889 2.921 16 A OTHC Dummy Fwd +140 µm (y) N2

0604 0.889 0.762 2.286 17 A OTHC Dummy Rev +140 µm (y) N2

0402 0.558 0.508 1.676 18 A OTHC Build Fwd +280 µm (y) N2

0201 0.381 0.228 0.838 19 A OTHC Dummy Rev +280 µm (y) N2

20 A OTHC Dummy Fwd +280 µm (y) N2 Table 5. Solder Paste 21 A OTHC Build Rev +140 µm (y) Air Material Label Alloy Type Metal Content (%) A Sn96.5Ag3.0Cu0.5 89 can cope with the “normal” offset shifts that occur in SMT assembly.

Conclusions During this experiment several points have been discovered: One of the most important is that a centered Pb-free print process should not cause concern for process engineers. Ensure that the repeatability and accuracy of the deposit is under control. As past investigations show, enclosed print heads and nickel/laser cut stencils enable deposition stability. But, of course, a utopian process does not exist within an assembly facility, therefore, these statements are true only when manufacturing within a laboratory facility. Therefore, we need to fully appreciate the influence that stencil geometries can have on FIGURE 4: Reflow oven profile. a real-life Pb-free process. Figure 12 shows the combinations of aperture designs and

1600 size. Some designs were extremely detrimental to the process, but 1505 design AZ (standard rectangle with 50 µm added per side) 1400 showed significant benefit for all passive components that exhib- 1200 it standard assembly offset creep. It would seem that this slight 1000 increase of solder paste volume aids the assembly process, partic- 800 ularly once the solder paste placement accuracy is breached. This 576 600 increased capability could be explained by the fact that the over-

400 print not only gives a “larger slop” area of placement for both 279 300

200 “paste on pad” and “component to pad” alignment, but the addi- 414 tional solder paste material balances the wetting forces during 0 0 Offset N2 0 Offset N2 140 micron X 140 micron Y 140 micron Y 280 micron Y 280 micron X reflow. A further benefit to this aperture design was that the OSP Offset N2 Offset Air Offset N2 Offset N2 Offset N2 pad was tinned, which is more a cosmetic feature but one that is FIGURE 5: Total number of assembly defects by process setup. ever present in the discussion of Pb-free assemblies.

48 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Pb-Free Printing Parameters

FIGURE 6: Photograph showing the complete 0201 process flow (140 FIGURE 7: Photograph of the complete 0201 process flow (140 µm µm +ve x with nitrogen). +ve y with nitrogen).

FIGURE 8: Photograph of the complete 0201 process flow (140 µm FIGURE 9: Photograph ofthe complete 0201 process flow (280 µm +ve y with air). +ve y with nitrogen).

The addition of nitrogen clearly increased the number of defects. This could be due to increasing the wetting forces and reduced wetting time of the solder during reflow. Longer thermal reflow profiles could reduce the number of assembly defects observed with nitrogen. One important observation is the different response FIGURE 10: Photograph of the complete 0201 process flow (280 µm between resistor and capacitor packages. The capacitor package +ve x with nitrogen). accounted for approximately 80% of the defects recorded. This defect rate was more noticeable on 0201 and 0402 capacitor packages once the solder paste was shifted in the y axis. These AX 50 packages both have a high height-to-width ratio, which sug- FZ AY 40 gests that the balance of total downward forces pulling down FY AZ 30 on the component is only slightly more than the surface ten- FX BX sion of the end faces; therefore when paste is misaligned, the 20 end face, which is not fully contacted with the solder paste, EZ 10 BY 140 micron X Offset N2 does not have sufficient surface tension to equal the pulling 0 140 micron Y Offset Air EY BZ 140 micron Y Offset N2 force of the opposite side. When this happens the chip component flips up due to imbalance of forces. This is not seen on EX CX larger chip components because the mass of these is greater than the end surface force. DZ CY DY CZ

Final conclusions: DX •Apertures that were rectangular in profile, and include an additional 50 µm on the east and west edge (assuming the FIGURE 11: Assembly defects by aperture design (140 µm offsets only). chip component is mounted vertically), display a greater assembly yield rate. •Using nitrogen within the reflow process is detrimental to the 60

assembly process window. 50 •Using the correct aperture designs can deliver a high yield 40 rate even when “paste to pad” or “component to pad” offsets creep into an assembly process. ■ 30 Defects

20 Clive Ashmore is manager, global applied process engineering group, DEK 10 (dek.com); [email protected]. 0 AX AY AZ BX BY BZ CX CY CZ DX DY DZ EX EY EZ FX FY FZ Aperture Design

0 Offset N2 0 Offset N2 140 micron X Offset N2 140 micron Y Offset Air 140 micron Y Offset N2 280 micron Y Offset N2 280 micron X Offset N2

FIGURE 12: Assembly defects by aperture design (all offsets shown).

circuitsassembly.com Circuits Assembly FEBRUARY 2006 49 Technology Innovations

Integrating AOI and Selective Soldering

Mark Cannon, Bob Klenke and Phil Zarrow

ever, as is lack of repeatability (due to operator A breakthrough machine for PTH mass variability) and lack of product traceability. Increased use of tiny surface-mount packages soldering combines AOI and selective such as µBGA, CSP and flip chip, together with expanded use of area-array SMT components, soldering in a single inline unit. continues to challenge board-level assembly. At the same time, packaging roadmaps forecast that ave soldering remains the most preva- PTH components will continue in power devices lent, efficient method for mass solder- and connector applications for the foreseeable W ing plated-through-hole (PTH) com- future, albeit at diminished volumes. This contin- ponents. Although mass soldering of PTH ued convergence of SMT and through-hole com- components, either by wave or dip soldering, has ponents means more mixed-technology assem- improved dramatically, the process generates one blies, which in turns means greater attention of the highest defect per million opportunities needs to be paid to PTH solder joint quality. (DPMO) rates in electronics assembly. Inherent Due to the physics involved with an unlimited characteristics of the process render it far from supply of flowing liquidous solder, all forms of perfect. Thus, post-wave manual inspection and PTH mass soldering – including wave, dip and hand touch-up have been common practices. aperture pallet soldering – result in various solder Pb-free implementation will not only make defects. Most common are bridging, insufficient this situation more severe, but will also aggravate solder, opens and miscellaneous solder-related the quality risks associated with manual touch- defects. Wave solder defects can result from insuf- up. The tighter process window and higher ficient wetting force, component shadowing, process temperatures for Pb-free soldering great- excessive lead protrusion or solder splashes. ly increase the risk of overheating adjacent com- While dip soldering can closely equal wave sol- ponents or damaging the board during manual dering throughput rates, solder defects can result touch-up and repair. from inadequate keepout area, board warpage or Meanwhile, AOI has gained acceptance in restricted solder peel-off. SMT as a technology that provides objective A method that has gained popularity for sol- results, enhances first-pass yield and enables dering mixed-technology assemblies is the use of traceability. However, AOI has not been com- masking, or aperture wave pallets. PCBs are monly used for PTH inspection in mass-solder- mounted in pallets that have cutouts to direct the ing lines where it is most needed because an flow of liquidous solder to the individual sites of operator is typically required to perform manual PTH interconnections. The pallets are run touch-up. The highly subjective nature of manu- through a wave solder machine so that the wave al inspection and repair is accepted practice, how- only makes contact with the PTH interconnec-

50 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Technology Innovations tions and not the SMT components that have been previously PCBs with area-array SMT packages and PTH components in reflow soldered. While this method substantially reduces bridg- particular will create significant challenges for Pb-free rework ing of SMT components, increased PTH solder defects can occur and repair. due to pallet design confines such as limited adjacent component While Pb-free solder alloys require higher processing temper- clearance, pallet thickness and draft angle resulting in shadow- atures due to the nature of their wetting properties, many PTH ing, inadequate solder contact and limited vertical hole fill. components can be damaged if their internal threshold temperature is exceeded by either rapid or excessive heating of the PCB Manual Inspection and Repair during soldering or manual touch-up. This is especially true in Manual touch-up with a soldering iron has always been a Pb-free repair since the process temperatures are typically 30° to risky undertaking at best. Hand soldering quality is completely determined by operator skill level and the efficiency of the soldering iron. From a repeatability standpoint, all solder joints should be made with the 'BTU&BTZ3P)4$PNQMJBODF4DSFFOJOH same temperature with dwell time regulated for variations in component thermal mass. The variable human factors associated with manual PTH inspection and repair generally result in inconsistent solder quality and unpredictable throughput. Problems t 3FBMUJNFOPOEFTUSVDUJWFDIFNJDBM associated with manual touch-up include lack of repeatability, operator dependant BOBMZTJT subjective inspection criteria, operator t 2VBOUJmFTUPUBM1C $E )H $SBOE#SJO fatigue, non-traceable results, risk of board TFDPOET damage and scrap, high cost for solder wire and replacement solder iron tips, operator t 5FTUTPMEFST DPNQPOFOUT QBDLBHJOH training, high labor costs, large floor space BOENPSF and low productivity. t -JUUMFUPOPTBNQMFQSFQSFRVJSFE One common shortcoming of manual inspection and repair is that repetitive t )BOEIFMEPSCFODIUPQPQFSBUJPOWJB touch-up is often carried out on a continual XJSFMFTT1$JOUFSGBDF basis without providing feedback for resolu- tion of wave soldering problems. The subjective nature of manual inspection and repair conducted concurrently by several operators rarely results in statistical process control (SPC) monitoring of solder defects. Repetitive touch-up data should be continuously tracked and a root cause analysis conducted to determine if the wave soldering process is in control, or if a specific component or pallet design is causing quality problems. Post-wave repetitive touch-up has a direct correlation to improper pallet design, poor wave optimization or inadequate thermal profiling. /*50/"OBMZ[FST #JMMFSJDB ."64" Impact of Pb-Free 4BMFT4FSWJDF8PSMEXJEF The higher process temperatures OJUPO!UIFSNPDPN XXXUIFSNPDPNOJUPO required for Pb-free soldering greatly impact assembly, especially in manual touch-up and repair processes. The higher thermal excursions required for rework increase the potential for damage to com- "OBMZ[Ft%FUFDUt.FBTVSFt$POUSPM ponents and boards. High thermal mass

circuitsassembly.com Circuits Assembly FEBRUARY 2006 51 Technology Innovations

40°C higher than the SnPb temperatures for which most PTH components were designed. When using a soldering iron, it is critical that the tip temperature remain constant. Because a soldering iron generally does not recover heat loss fast enough, however, touch-up and repair operators attempt to compensate by using higher set temperatures, typically 380° to 440°C. These already high solder iron temperatures will be even higher for Pb-free. The problem: a soldering iron tip – with a relatively low mass – is heated by a heating element – with relatively low power – and as heat is transferred to each consecutive joint, the tip temperature decreases (Figure 1).How well a soldering iron puts back the heat lost at the tip and how long the tip remains on the joint ultimately determines the actual joint temperature. Although manufacturers are developing better irons, accurate, repeatable results are impossible to achieve manually. In addition, traceability is nearly impossible. Finally, skilled hand-soldering operators will need to be retrained and re-equipped when implementing a Pb-free process. Factors challenging manual inspection and touch-up in a Pb- FIGURE 1: Typical solder iron temperature degradation. free environment include: •Changes in visual inspection criteria. •Soldering iron design limitations. • 100% operator dependence. •Higher working temperatures. •Operator fatigue. •Operator skill retraining requirements. •Potential false calls. •Greater tendency for lifted pads and board damage. •Higher direct labor costs. •Higher costs of additional factory floor space. The new products, technologies •Higher running costs (solder tip wear, solder wire, scrapped and ideas to help you boards, etc.). •Lack of repeatability or traceability. The philosophy behind in-process inspection is that it catch- build it smaller, es a defect at the process center that produced the error, where it costs less to correct the error in terms of time, labor and materi- faster, better. al in the assembly process. In-process inspection also facilitates The NEPCON family of events root cause analysis with regard to the source of the defect so that for 2006 the offending process can be immediately rectified before more defects are generated. When inspection is not integrated into an assembly line, it is often supplanted by offline manual inspection and repair that is decoupled into “islands of inspection,” resulting in longer reaction time to correct an offending upstream process, such as wave soldering. Using AOI for in-process inspection can detect defects (with the exception of faulty components), thereby providing high value-add at low cost to improve and maintain process yields, and functioning as a feedback tool for immediate process improvement. AOI provides inspection coverage for defects such MAY 10 -11, 2006 as solder bridging, missing or displaced components, and wrong Boston, MA, USA components, so that all defects that occur during assembly are For more information, visit: detected. To this extent, AOI affords several advantages over in- www.nepconeast.com circuit test (ICT) in that programming time is generally hours versus days, plus the use of dedicated fixtures is eliminated. One of the pitfalls of AOI is false calls, or pseudo errors, Produced and Managed by including false alarms or bogus defects that typically occur as a result of the behavior of the software algorithms in combination with the imaging process. For AOI to function as a meaningful

52 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Technology Innovations

uidous solder. The wettable solder nozzle is ideal for PTH repair since peel-off parameters are fully programmable and can precisely remove a solder bridge, or re-solder an insufficient or open solder joint (Figure 2).Italso maintains the lowest possible working temperature – maximum of 285°C for Pb- free – which replaces the hand soldering working temperatures of 380° to 440°C. An added advantage of the wettable solder nozzle is that the keep-out area around the nozzle is significantly less than the adjacent component clearance of aperture wave pallets or the keep-out area of dip soldering. The wettable solder nozzle can repair PTH solder joints as close as 0.5 to 1.0 mm between aPTH pad and an adjacent SMT pad, equal to hand soldering and significantly less than typical aperture pallet clearances of 2.5 to 3.0 mm and dip soldering keep-out areas of 3.0 to 5.0 mm. FIGURE 2: Wettable selective soldering nozzle with constant temperature. Automated Inspection and Repair tool, the frequency of false calls must be reduced to an acceptable The best that most standalone AOI systems can do is inspect minimum while maintaining maximum system throughput. defects out of a process rather than preventing them, which con- A 99.5 to 99.7% first-pass yield for AOI inspection can result tradicts Six Sigma quality principles. A proprietary new system in as many as 15 to 25 pseudo defects for a board containing combines AOI technology with an automatic selective soldering 5,000 SMT solder interconnections. This relatively high frequen- system that has the ability to inspect, correct and verify solder- cy of false calls is caused by the difficulty in discriminating between the considerable number of different SMT component US AT APEX sizes, shapes and interconnect configurations. Through-hole sol- BOOTH #2433SEE der joints, on the contrary, always look similar regardless of the component type when viewed from the solder source side of the Place More board. This results in a false call rate for repairable PTH soldering defects such as bridges, insufficient solder and opens, that is 10 times lower than typical SMT pseudo defects. Flexible. Approximately 99% of all AOI installations are used for SMT applications such as post-print, post-placement or post-reflow while PTH applications account for less than 1%. This is some- what of a revelation as world-class, in-process quality for SMT assembly typically ranges between 50 to 200 DPMO while PTH assembly is considerably higher (2,000 to 3,500 DPMO). While it is uncommon to use AOI for PTH inspection in mass soldering lines, that is where it is most needed due to higher DPMO rates.

Selective Soldering Selective soldering permits the user to optimize the soldering process to the pin level versus the compromise techniques in flux application and contact time with mass soldering. Since flux deposition, nozzle height, solder dwell time and peel-off parameters are fully programmable and can be optimized for individual components, it is an ideal method for repairing PTH solder interconnections. The ideal system for Pb-free repair should provide uniform ESSEMT EC heat distribution and incorporate features to prevent the repaired PRODUCTION EQUIPMENT FOR ELECTRONICS component, and adjacent components, from overheating. Selec- www.bemoreflexible.com tive soldering meets this requirement by delivering constant, local- 1-888 ESSEMTEC ized temperature via an unlimited supply of recirculating liq-

circuitsassembly.com Circuits Assembly FEBRUARY 2006 53 Technology Innovations

Table 1. Conventional Manual Post-Wave Inspection and Touch-Up Table 2. Automated Post-Wave Inspection and Repair Function Manual Operations Function AOI+R Operations Manual inspection time per solder joint 1.5 sec. AOI+R inspection time per board 12.0 sec. Touch-up hand soldering time per defect 5.0 sec. AOI+R repair time per defect 1.5 sec. Total number of PTH joints per board 80 Total number of PTH joints per board 80 Total time to inspect board 2.00 min. Total time to process board 28.8 sec. Average defect rate from wave solder process 1.00% Average defect rate from wave solder process 1.00% Number of joints requiring touch-up/board 0.80 Number of joints requiring touch-up/board 0.80 Total time per board 2.07 min. Total time per board 0.48 min. Total boards per shift per operator 232 Total boards per shift per AOI+R 1000 ing. Called AOI+R, it is a fully automated optical inspection and iron. After repair, the PCB can be either selectively rescanned to repair system for PTH and mixed-technology assemblies in a sin- confirm defect correction or sent for further post-wave process- gle machine. The system is automatic and closed-loop, reducing ing. Repaired boards exit the system only when a “pass” condi- the problem of human subjectivity and error. tion is guaranteed and are transported back to the inline work- Immediately following mass soldering, boards are inserted flow process for near “zero defect” mass soldering. All process into the system, where each PCB is automatically scanned. When data for the inspection and repair processes are documented for a defect is found, an automatic command is sent to the selective quality control and traceability. soldering module where the board containing defects is auto- When multiple mass soldering lines are in operation, inspec- matically programmed and immediately repaired. No additional tion can be performed on each line using an inline AOI+ scan- programming or operator intervention is required. The exact ning module (AOI+iL), after which boards that pass inspection position and defect type determines the automatic repair pro- continue through the module and move down the line. Mean- gram. A wettable selective nozzle that is covered with a nitrogen while, boards containing defects are transferred to a centrally blanket completes the repair process. The temperature and qual- located AOI+R machine for repair. When a repairable defect is ity of the repaired joint is superior to that of a hand soldering detected, the appropriate repair command is generated and net-

54 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Technology Innovations

Table 3. Comparison of Throughput and Cost Savings insufficient destination side vertical hole fill. Yet over 85% of Function Justification post-wave defects are repairable such as solder bridges, excess sol- Production goal/day 3000 boards der or bulbous joint, insufficient solder and solder splash. Average direct hourly rate $9.00 Finally, an AOI+R module can be integrated as a subsystem Burden rate 35% within a wave solder machine. This forms a new concept in mass Burdened hourly rate $12.15 soldering, “progressive wave technology,”consisting of chip wave, Hours per shift 8 finishing wave and selective wave, all in one machine. This three- Days per month 21 wave process permits boards to be processed within a true closed- Operators required for manual operation 13 loop system before exiting the machine. In line with Six Sigma Direct labor cost per month – manual operation $26,535.60 principles, progressive wave technology does not repair boards but Operators required for AOI+R operation 1 rather corrects defects internal to the process center and eliminates Direct labor cost per month – AOI+R operation $6123.60 non-value-added end-of-line inspection and touch-up. ■ Annual direct labor savings $207,944.00 Breakeven point 10 months References

International Electronics Manufacturing Initiative, "2004 iNEMI Board Assembly Roadmap," worked via data transfer to the AOI+R machine. Boards contain- June 2005. ing defects are then transferred to the offline machine, which Bob Klenke, "Lead-Free Selective Soldering: The Wave of the Future," SMTA International functions as a centralized repair cell requiring only one operator. Proceedings, September 2002. Defective boards are scanned via bar code and manually loaded Reinhard Klein Wassink, "Soldering in Electronics," Electrochemical Publications, 2nd edi- into the machine. The defect and repair command is sent to the tion, pp. 107, 1989. selective repair module that conducts the repair. Immediately Ron Daniels and Bob Klenke, internal ITM Consulting document, May 2003. following repair, the board is automatically rescanned for correction validation. Boards that have a non-repairable defect are Mark Cannon is president and COO, ERSA GmbH (ersa.de); mark.cannon@ identified and stacked separately for manual unloading. ersa.de. Bob Klenke is a principal consultant at ITM Consulting (itmconsulting. This closed-loop system provides full product traceability and org). Phil Zarrow is president and principal consultant, ITM Consulting. board tracking throughout inspection and repair processes. Unlike manual inspection and touch-up, the need for segregated US AT APEX board handling and traceability concerns are eliminated. BOOTH #2433SEE The operational differences between manual inspection and touch-up and the new machine can be illustrated by evaluating a Solder typical PTH assembly in terms of cost, throughput and defect rates (Table 1). Only the manual inspection and touch-up time are reviewed as the wavesolder system and secondary operations prior More Flexible. to wave soldering are non-limiting operations. Subjective inspection criteria will often generate false calls, leading operators to overcorrect by touching up good solder joints, which substantially increases the potential damage to components or the board. In this example, five operators are required to manually inspect and touch-up 1,000 boards per 8 hr. shift. To process a larger volume of boards, such as 3,000 per 24 hr. workday, several more operators are required resulting in additional floor space, added cost, longer process times and increased variation in process quality. By implementing AOI+R, the nonuniform demand condition is eliminated from post-wave inspection and repair and work-in- process inventory is reduced (Table 2).Upstream process response and wave-soldering corrective action are effectively speeded, thereby enhancing process yields, improving quality and reducing scrap (Table 3).

Conclusion ESSEMT EC Mainstream in-process quality rates that are historically 2,000 PRODUCTION EQUIPMENT FOR ELECTRONICS to 3,500 DPMO after wave soldering can be reduced to below 200 www.bemoreflexible.com DPMO using the new system. The remaining defects that cannot 1-888 ESSEMTEC be repaired by the machine: missing or skewed components or

circuitsassembly.com Circuits Assembly FEBRUARY 2006 55 EMS RoHS Models

Outsourcing RoHS-Compliant Production at a Distance

Eric Liew, Fadzol Zaman and Sivakumar Thanupillai

In migrating to Pb-free processes, Beyonics An Asian EMS provider’s perspective on Technology Ltd. (beyonics.com) encountered a number of issues. These included: challenges and potential solutions. •Upgrading reflow and solder wave equipment to meet higher melting temperature process utsourcing electronics production off- specifications. shore has always been a more complex •Formulating suitable operating procedures to O process than localized manufacturing identify and segregate Pb-free materials to strategies. RoHS compliance adds product re- prevent contamination. design, supply base requalification, process quali- •Changing incoming part inspection practices fication and the learning curve issues associated to identify part integrity for consigned and with a standard that is still in development to the direct purchase material. prior complexity of communicating at a distance •Re-optimizing process parameters and process across multiple time zones. design standards to meet different alloy behav- This article discusses one Asia-headquartered ior characteristics. EMS provider’s Pb-free process implementation •Evaluating issues related to components’ heat strategy and some typical challenges associated sensitivity, terminal finishes and molding with managing RoHS-compliant process transi- compounds. tion at a distance. It also discusses the issues that •Higher indirect material costs. arise as the result of cultural differences in cus- In addressing these challenges, Beyonics tomer business models across multiple regions. focused on five areas: 1. Collaboration with customers to ensure compliance with their internal Pb-free initiatives. 2. Employee training on Pb-free processes and control. 3. Development of internal processes through use of a pilot line. 4. Collaboration with customers and suppliers to ensure access to RoHS-compliant material in line with process parameters. 5. Implementation of new process monitoring equipment to manage tighter process windows and monitor contamination. FIGURE 1: A Pb-Free SMT line in Beyonics Technology’s Kulai, Malaysia In the transition to Pb-free and RoHS compli- campus. ance, the company did not embark on process

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circuitsassembly.com Circuits Assembly FEBRUARY 2006 57 EMS RoHS Models alone. Materials suppliers, equipment suppliers and technical organizations were all great resources in developing and validat- ing acceptable processes.

Two Business Models Beyonics began implementing its Pb-free process in 2003 to support a Japanese customer. Japanese manufacturers were strongly advocating elimination of hazardous materials in their processes while the RoHS directive was still in development. The Japanese standards closely followed RoHS compliance. In April 2005, Beyonics’ processes were enhanced to comply with the RoHS directive. Currently, the company supports volume RoHS- compliant production for a range of customers from multiple regions in the disk drive, wireless applications and consumer electronics industries in Singapore, Indonesia and Malaysia. In FIGURE 2: An operator verifies machine programming prior to produc- addition, the company has two business models to support the tion start in a Pb-free line in Beyonics’ Kota Tinggi, Malaysia facility. preferred business framework of its Japanese customers and U.S./European customers. This may affect the accuracy of the printing equipment to The key difference in the two models is degree of control. In the align stencil apertures to PCB pads. Concerns include varia- Japanese model, the supply base, inventory management and tion of positional accuracy of PCB, variation of alignment process choices are controlled by the OEM. In the U.S./European capability of printer and variation in the stencil itself. model, the EMS provider is responsible for material procurement, • Design of experiments conducted to study stencil aperture, inventory management, DfM recommendations and process con- paste volume, PCB pad size, printer parameters are important trol. In both cases, the EMS provider is expected to use its manu- in developing a manufacturable product. facturing expertise to improve efficiency where possible and the • PCB layout design. PCB pad size and shape may change; how- OEM and EMS provider team in continuous improvement efforts. ever, design guidelines in this area can vary based on product The differences in business models drive differences in EMS complexity. provider responsibility for RoHS transition issues. • Component selection. The component’s temperature toler- Beyonics uses a SAC 305 alloy in its manufacturing process. It ances or maximum ramp rate (degrees/sec.) have always been was chosen through internal process studies, though it is consis- important for Pb-free processing. Evaluate each component’s tent with the recommendation of IPC Solder Products Value ability to withstand heat, and understand the compatibility of Council. This alloy melts at 217°C. As tin is the major element, its lead finish and moisture sensitivity level (MSL) with the reflow temperature is high. The higher temperature increases the Pb-free process parameters. oxidation rate and tin has a higher oxygen affinity. Since the oxi- Supply Base Management and Inventory Control. Material integrity dation rate is enhanced even further, an inert nitrogen atmos- is as much of a challenge within the Asian supply base as it is in the phere is used in the reflow process for most products. U.S. Within the Japanese OEM model, customers test all material Also, the effective process window is narrower because these prior to consigning it. Within the U.S./European model, the stan- solders have a higher liquidus temperature, and materials present dard practice of combining incoming inspection and preferred in the PCB limit the maximum temperature they can sustain for suppliers willing to certify material as RoHS compliant is used. a given amount of time. Nitrogen reflow supports these narrow- Incoming quality assurance practices include a verification er process windows because it contributes to improved wetting, process which checks the RoHS identification list from each sup- shinier appearance, fewer voids in BGA and QFP joints, and plier and the latest threshold value information of the RoHS-rel- more consistency in BGA balls. As there is less flux residue in a evant substances. Invoices and analysis/inspection data is also nitrogen atmosphere, in-circuit test yield is enhanced, because checked for each delivery batch. Finally, the inspection report test probes easily penetrate the flux to the test point. must contain a visible RoHS stamp, shipment date and lot/batch number information to support traceability should contamina- Typical Project Transition Issues tion issues subsequently be detected. Product Redesign. While each project may have unique RoHS-compliant material is physically segregated from mate- redesign needs, Beyonics’ basic DfM guidelines identify the fol- rial used in SnPb product. Employee training includes material lowing as areas of focus: on RoHS-compliant packaging markings and appropriate stor- • Stencil design. In stencil printing some factors will change, age procedures. others will not. Solder paste printability depends heavily on Process Control and Product Compliance. Strict internal proce- flux formulation but not on alloy type. Because Pb-free alloys dures regulate storage of material on the production floor; oper- do not spread or wet as well as lead alloys, any solder paste ators follow a material integrity verification procedure. Solder printed on the PCB will remain close to where it was printed. purity in production areas is monitored daily using a Malcom

58 Circuits Assembly FEBRUARY 2006 circuitsassembly.com EMS RoHS Models

STA-2 impurity checker. Solder joint quality testing includes should also focus on analyzing the contractor’s preferred busi- cross-sectional and structural inspection. ness model, range of internal RoHS transition expertise/support Some projects include third-party audits of sample lots of fin- capabilities, past track record with projects of similar size and ished boards by the solder supplier to verify RoHS compliance of scope, and team communication methodology. ■ materials. In addition, customers may also have incoming inspection procedures. Eric Liew, Fadzol Zaman and Sivakumar Thanupillai are in technical When unacceptable levels of defects are detected, joint management positions at Beyonics (beyonics.com) in Indonesia and Malaysia. process studies are initiated. For questions related to this article contact Raymond Yee; raymondyee@sg. Pb-free compliance is implemented in stages. On one cordless beyonics.com. phone product, allowable Pb contamination (impurity) level in wave solder was reduced from an initial control limit of below 3000 ppm at process initiation in 2002 to a level below 800 ppm in 2005 to comply with RoHS.

Areas to Audit Areas to be audited prior to transitioning Pb-free projects to an offshore contract include: •Compatibility of contractor support infrastructure with services needed. •Ability of contractor to support redesign efforts and component sourcing changes. •Internal supplier processes for material integrity and traceability. •Internal and third-party audit procedures to monitor contamination. •Internal procedures related to monitoring changes in the RoHS directive requirements and ensuring smooth implementation and appropriate customer notification/approvals for any resultant process or materials changes. •Track record of supporting customer quality and process improvement initiatives. •Communication processes between customer, contractor program and engineering teams. •Ability to support evolving process requirements. Implementing RoHS-compliant projects is complex because there are many variables to consider. Distance increases that complexity. Understand both a contractor’s internal processes and the business models it uses for customer interface. While offshore sourcing does complicate communication, in some cases it also provides access to a greater base of knowledge. For instance, contractors with Japanese customers may have several years of volume Pb-free production experience. Initial screening of offshore sourcing options should include onsite evaluation of each contractor’s internal systems. Audits

circuitsassembly.com Circuits Assembly FEBRUARY 2006 59 Supply Chain Solutions

The Supply Excellence Project at Ericsson and Solectron

Ylva Andersson, Jan Melin, Rolf Broström, Lindsay Ballantyne, Dave Cooper and Lennart Ivarsson

of a number of cabinets, each about the size of a How a major OEM and EMS firm teamed large refrigerator, linked to a central processor. Each cabinet is packed full of electronics and is to cut lead time by 75% on a complex, linked to others via a vast array of custom configured custom cabling. A node can consist of custom telecom product. one cabinet or 10 depending on the customer order. No two nodes are the same and the final o meet customer orders for just-in-time configuration is unknown until the customer deliveries, Ericsson and Solectron collabo- places the order. T rated to design a more effective supply Therefore, the production system is a config- chain that reduced manufacturing lead-times ure-to-order (CTO) environment. PCB assem- drastically. The two companies worked together blies are built-in and then configured into maga- to develop a streamlined process, blending ele- zines; the magazines are then configured into ments from both Lean and Agile manufacturing. cabinets. Each node has approximately 450 As a result, the delivery performance to commit assemblies. Finally, the deliverable product is reached an average of 99% for a highly complex completed when all the required cabinets are “node” telephone switching system. The acknowl- cabled together and tested as a complete node. edged lead-time was reduced by 75% – including Final system test takes a maximum of three days a full available to promise (ATP) check. of continuous testing, depending on the com- Ericsson, the largest global supplier of mobile plexity of the node. wireless communication systems, faced increas- The resulting supply chain is extremely coming demands from its customers to cope with plex. The chain starts with components for increased volatility and to reduce lead times. assemblies, which are built in Europe and China, Solectron was under pressure from Ericsson to adapt supply-chain processes to produce both higher Manufacturing product quantities and quicker Lead-Time delivery response time. ATP PCBA Fab Subassembly Systems Ship The product was 100% build- (Available to Integration to-order, with zero finished goods Promise) and a complicated integration. The Solectron siteinEurope Inventory supplied Ericsson with large, very complex telephone switching sys- FIGURE 1: Under the preexisting business model, manufacturing and tems called nodes. A node consists fulfillment were joined.

60 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Supply Chain Solutions various items of metalwork and mechanics, CPUs and literally the KPIs were continuously communicated and accessible to all miles of cables. One order consists of approximately 2,000 dif- employees (Figure 3).A steering committee met every second ferent parts from 150 suppliers. week and sub-project managers were brought together each Even in a stable environment with a predictable demand fore- week to formally review the progress of each sub-project plan. cast, many variables can prevent a smooth flow of the supply Primary focus was on delivery performance for which the target chain and detract from delivery performance (Figure 1).Add the was set at 98%. ever-growing expectations of Ericsson’s customers and excel- The initial sub-projects addressed the full scope of the supply lence in supply performance becomes challenging indeed. chain, from improvements in component sourcing to faster To balance increasing volatility for a highly complex product completion of the final product. A key element was decoupling with shorter lead-time expectations, Erics- son and Solectron initiated what the companies called the Supply Excellence Project. The project aimed to optimize the supply chain to speed Solectron’s delivery performance. The short-term focus was to improve deliveries, and the long-term vision was to position Solectron to meet the demands of Ericsson’s end-customers. After Solectron and Ericsson agreed to a formal project structure, the joint steering team tracked the progress of the project every two weeks during review meetings. The project was divided into sub-projects, each with a formalized and well-documented scope. The five sub-projects were defined as: • ATP project. The goal was to redesign the processes and supporting IT so ATP happened in hours, automatically. • Buffer inventory. The project strategically built inventory to support demand variability in CTO environment. • Systems integration (NPC) project. Reduced manufacturing/test times, CTO, to achieve lead-time of less than three days. • Pick and pack project. Enabled short lead- times for selected products without any value-add. • Supply chain project. Focused on decoupling of supply center and fulfillment center, PCBA inventory buffering, tacti- cal supply chain improvements and manufacturing lead-time reduction (Figure 2). Sub-project managers were appointed from various functions within the Europe site. Reporting lines were clear, as were the targets. Key performance indicators (KPIs) were identified,each with aggressive quarterly targets for the remainder of the year with longer targets set for subsequent years. Weekly publication of the KPIs com- menced immediately, giving high visibility of progress to executive management at both Solectron and Ericsson. In addition,

circuitsassembly.com Circuits Assembly FEBRUARY 2006 61 Supply Chain Solutions node manufacturing from assembly manufacturing, whereby the internal supply chain of completed boards was to Supply Center Fulfillment Center be redeveloped to match the way external Manufacturing Lead-Time suppliers were managed. Order Commit Other key indicators included: creating a strategic buffer of material to Board Fab Auto System Ship absorb short-term fluctuations in Subassemblies-MTS Integration demand, automate the ATP process to Inventory Inventory reduce the time for Solectron to con- (5) (3) firm order fulfillment and reduce node Pull Signal manufacturing lead-time. Additionally, the team concentrated on differentiating the process for dealing with orders for FIGURE 2: The new model added buffer inventory but reduced lead time by 60% in manufactur- “simple” product from the way complex ing and 75% overall. node orders were handled. A KPI was established to measure how quickly reduction in the Node MLT (Lean think- Solectron could Pick and Pack simple ing) means that product throughput is products. much quicker than in the past. The third reason for success was the focus of the Lean Meets Agile combined management team of the two During the past few years, Solectron partners. Last, Solectron and Ericsson has been driving the transformation collaborated to identify where expert toward Lean manufacturing and Six resources would offer the most benefit. Sigma. In an effort to increase efficiency, These factors, combined with the man- techniques have included reducing work- agement team’s daily focus on the KPIs, in-process (WIP), moving toward single generated a “success culture.” piece flow, implementing “lightning” changeovers and removing non-value- Results added tasks from all processes. Solectron reached a high delivery Ericsson, on the other hand, follows performance rate. The supply chain had the principles of Agile manufacturing. stabilized: the delivery performance The principles of Agile are designed to reached an average of 99% for the previ- address unpredictability in an environ- ous quarter and acknowlegded lead-time ment of constant change, which explains was reduced by 75% – including a full the use of buffer inventory. Agile manu- FIGURE 3: Large overhead monitors kept run- ATP check. facturing focuses on the ability to accom- ning score on Solectron’s performance. Solectron and Ericsson created a win- plish rapid changeover between the man- ning concept by working collaboratively ufacture of different assemblies. Lean is about taking things that and blending elements from both Lean and Agile manufactur- can be controlled, such as the manufacturing process, and con- ing. The next step is a more robust supply chain that will have tinuously improving them. When Solectron and Ericsson agreed world class performance on delivery precision to requested deliv- that the main KPI was delivery precision to the requested delivery date. The average lead-time should realistically be cut by ery date it was easy to see how to use the Lean concept to get an another 50%. ■ Agile supply chain that could fulfill customers requirements. Combining the forces of Lean with the Supply Excellence Ylva Andersson is director of supply chain, Solectron (solectron.com). Jan Project was key and progress toward meeting the KPIs set by Melin is VP, operations sourcing and supply business unit systems, Ericsson Ericsson accelerated. The NPC lead-time project also gained (ericsson.com). Rolf Broström is director of operations excellence, operations momentum and manufacturing lead-time (MLT) for nodes sourcing and supply, business unit systems, Ericsson. Lindsay Ballantyne is reduced significantly. Very quickly, the delivery performance to supply project manager, Solectron. Dave Cooper is VP, supply chain solutions, commit reached, and stayed above, the 98% target and within a Solectron. Lennart Ivarsson is VP of global program management, Solectron. few months the MLT was cut by more than 60%. At a high level, probably four major factors explain the success of the supply project. First, the successful implementation of the inventory buffer (Agile thinking) permitted the integration site to absorb week-to-week demand variances. Second, the huge

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® Procurement

The Future of PCB Procurement

Mike Buetow

ers, didn’t pan out. … [W]ho needs a broker Will component distributors take on PCB when most of the North American companies are either in Asia manufacturing boards themselves, sales? or well acquainted with the Asian fabricators independent of M-Wave?” omeone recently emailed to me a column Calling the problems at M-Wave symbolic of written ostensibly on the “demise” of M- the entire board distribution industry requires a S Wave (mwave.com). M-Wave, you may huge leap in logic. It is a faulty assumption; recall, was once riding high, with a stock whose indeed, the PCB distribution market is growing price bolted from about $1 to over $15 in under by leaps and bounds. 24 months. The company had dreams of hitting Another flaw in this logic: M-Wave’s net sales $100 million in sales using a model that com- were $16.6 million by September 2005, an bined traditional PCB manufacturing and increase of 22.1% year-to-date. Gross profits were board-brokering services. up 34% to $3.2 million. That does not sound like Like so many others, the company did not a company in a market on life support. In fact, quite live up to its promise. Sales crashed. The most of M-Wave’s problems can be tied to past board shop and other assets were sold. Bankrupt- financial mistakes, not a poorly conceived busi- cy and delisting ensued. Little remained, except ness model. for the brokerage business. Howisthe board distribution market shaping All of which prompted the submitted column, up these days? And what will it look like in the which read in part: “[I]t appears that M-Wave’s future? To understand where PCB distribution business model, that of a board broker between may be headed, we need to look at the broader North American customers and Asian PCB mak- components distribution market. That sector today is characterized bytwo Table 1. Top 10 Distributors, 2004 groups: franchises and indepen------Calendar 2004 ------% Revenue ------dents. Franchises are the larger of Co. Revenue ($m) % Change 03-04 N. America Passives the two. The top 10 franchised dis- Arrow Electronics 10,646.1 23 57.5 N/A tributors had global sales of $37 1 Avnet 10,766.0 13 52 9 billion in 2004, up 20% from $30 Future Electronics 3,381.7 N/A 70 N/A billion in 2003.1 Combined sales of Bell Microproducts 2,827.8 27 40 8 the two largest, Arrow and Avnet, 1 Memec 2,172.6 N/A 44 0 made up 54% of the total.1 2 TTI 877.0 35 75 100 Independents, meanwhile, are Smith & Associates 513.0 61 100 N/A smaller but no less successful. Newark InOne 521.5 12 98 56 Revenue at the top 10 indepen- Digi-Key 530.5 33 93 61 dents was $2.4 billion in 2004, up All American 410.0 30 100 8 nearly 15%.1 The largest, Smith & 1 2 Merged; Includes Mouser. Source: Reed Research Group, March 2005 Associates, grew 60%.

64 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Procurement

Catalog distributors grew faster than the broader distribution Tier three is PCB fabricators that also offer brokered boards. industry in North America in 2004, according to the National Just how many fabs in North America do this is widely debated. Electronic Distributors Association (neda.org).2 Catalog distrib- However, by most accounts the number is large. One source utors, whose ranks include Digi-Key, Mouser, Allied and Newark says that when the question was posed to 40 or so company rep- InOne, cater to engineers who buy low volumes of components, resentatives at the IPC PWB Presidents Meeting last year, more often for prototyping. Broad-line and specialist distributors, on than 30 raised their hands. According to an IPC poll (ipc.org), the other hand, focus on large accounts. 33% of the revenues from PCBs sold in North America by Overall, the distribution market is doing just fine. 2004 was domestic fabricators in October came from boards produced the industry’s best year since 2000 (Table 1).When the final offshore.4 numbers for 2005 are in, year-on-year growth high in the single digits is expected. The bulk of component distributors follow one of two models: pure play (passive and active components only), or dual distribution/EMS services. Eight of the top 25 worldwide distributors offer EMS services. For the top tier, the trend since the late AOI and X-Ray 1990s has been away from combining the services; Reptron (reptronmfg.com) is among the notables who have split. Among See what you´ve been missing! lower tiers, however, a number serve dual roles; examples include World Micro (worldmicro.com) and Sarco (sarco.org). Optical and X-Ray What the distributors have not seized upon are PCBs. According to research firm Inspection Systems Henderson Ventures, PCBs were a $42 bil- For Every Step in Your lion worldwide industry in 2005.3 Yet component distributors have stayed away, in Assembly Process large part because the smaller volumes and custom nature of PCBs make a poor fit with the catalog-style line cards offered by distributors. In the absence of the bigger players, a large (and growing) group of small firms Dont Compromise have filled the void. The PCB distribution On Defect Detection industry can be segmented into two or three tiers. Tier one distributors, such as M- Viscom's comprehensive 4M Inspec- Wave, are characterized by dozens of clients tion LibraryTM, which meets IPC and multiple PCB suppliers (Table 2).They Class 2 and 3 requirements, along with have sales in excess of $1 million per Viscom's Integrated VerificationTM, month. assures you of 100% defect detection Tier two is the broadest category. Firms with the lowest possible false-reject TM may have a handful of clients and suppliers, rates. Plus, Viscoms EasyPro user- or dozens of clients but a single PCB sup- friendly interface makes programming plier, or no dedicated PCB broker. Electron- quick and easy. All Viscom systems are completely ready for lead-free ic Components Marketing Group (the inspection, with no modifications neces- ecmg.com), which reps Circatex in the U.K. sary. and Ellington in China, is run by Bob Mills, son of Viasystems founder James Mills. www.viscom.com Westwood (westwoodpcb.com) and Nypac E-mail: [email protected] Tel.: (678) 966-9835 (nypac.com) sell for Nanya. Staci (stacilc. com) in Florida and U.S. Tech in Ohio bro- See us at: ker more than just PCBs. Same goes for San Hall C-2363 Jose-based Addison Labs, which is very secretive.

circuitsassembly.com Circuits Assembly FEBRUARY 2006 65 Ad Index ADVERTISER INFORMATION: To learn about the Procurement advertisers in this issue, go to circuitsassembly.com and select “Advertiser Information” in the Magazine section of the home page menu. This will provide you with direct links to the home or product pages of each adver- Distribution Trends Table 2. Some Tier One Distributors tiser in this index. For distributors, “[a]dding the service M-Wave (mwave.com) Company Page No. part of their business is helping them take PD Circuits (pdcircuits.com) Aim Products, www.aimsolder.com...... 29 margins higher,” says Tucker Anthony Bare Board Group (bareboard.com) AMTECH, www.solderproducts.com...... 25 Sutro Capital Markets analyst Robert Epec (epecpcb.com) Aqueous Technologies, www.aqueoustech.com ...... 42 5 Asahi Chemical & Solders, www.asahisolder.com ...... 9, 27, 67 Damron. Among the offerings: Bare Board Group, www.bareboard.com ...... 57 •Design services. to be lower, with more component vari- BP Microsystems, www.bpmicro.com ...... 33 •Assembly, other procurement services. ability, and programs are heavy on new Cookson Electronics Assembly Materials ...... 46, 47 www.alphametals.com •RoHS component guidance. product introduction and engineering. Delta F, www.delta-f.com...... 57 •BoM scrubbing. This plays into the hands of catalog dis- Digi-Key Corporation, www.digikey.com ...... 2 EFD, Inc., www.efdsolder.com ...... 61 •Component kitting. tributors. Electronic Interconnect, www.eiconnect.com ...... 5 •Tracking/IT. “I think certain segments of the distri- Electronics Group of Henkel, www.electronics.henkel.com . . . . . 4 The underlying reason for distributors bution and EMS industries will converge EMA Design Automation, www.ema-eda.com ...... 1 to move into more value-added services is slowly over the next 20 years,”says Carter EMC Global Technologies, www.emcgti.com ...... 43 ERSA, www.ersa.net ...... 37 clear: Slim margins. In the fiscal year Shoop, an EMS analyst at Deutsche Bank Essemtec USA, www.essemtec.com ...... 53, 55 ended July 2005, Arrow reported a gross (db.com). Some have started. In July Eunil, www.eunil.com ...... 79 margin of 4% and net margin of 2.1%. 2005, RAD Electronics Inc. (rad-tech. Hover Davis, www.hoverdavis.com ...... 31 HumiSeal, www.humiseal.com ...... 19 During the same period, Avnet reported a net), an EMS firm, purchased the assets I&J Fisnar, www.ijfisnar.com ...... 77 gross margin of 2.9% and a net margin of of Astrex Inc., an electronics distributor. Indium Corporation of America, www.indium.com ...... 7 just 1.5%. In a statement, RAD said it expects 2006 IPC, www.goipcshows.org ...... 75 7 ITW Chemtronics, www.chemtronics.com ...... 28 For many of these companies, profits sales to exceed $100 million (up from $3 8 JUKI Automation Systems, www.jas-smt.com...... 20, 21 are generated from high inventory turns. million in 2001 ). Nor did it see any Kester Solder Company, www.kester.com ...... 13, 35 Still, expect distributors to add services to inherent conflicts. Asserted CEO Charles KIC, www.kicthermal.com ...... 41 build margins. Engaging in such pro- W. Mann: “We see substantial cross-sell- Kyzen Corporation, www.kyzen.com ...... 54 Machine Vision Products, www.machinevisionproducts.com . . . . 73 grams will put them head-to-head with ing opportunities to our mix of OEM, NEPCON China, www.nepconchina.com ...... 87 their EMS customers, who are also mov- contract manufacturer and reseller cus- NEPCON East, www.nepconeast.com ...... 52 ing into supply-chain management terri- tomers.”7 NITON Analyzers, www.niton.com ...... 51 OK International, www.okinternational.com...... C4 tory to remedy horrendous margins. The counter argument, consultant P. Kay Metal, Inc., www.pkaymetal.com ...... 23 Moreover, from the flank come so- Susan Mucha notes, is that the pure EMS PBR Seminars, www.pbrseminars.com ...... 91 called third-party logistics providers model is very service-focused and doesn’t PCB Design Conference West, www.pcbwest.com ...... 81 Qualitek International, Inc., www.qualitek.com...... 17 (3PLs), including DHL, FedEx and UPS. lend itself well to the same level of com- Ray Prasad Consultancy Group, www.rayprasad.com ...... 57 The top 100 3PLs control almost 33% of moditization found in distribution. Samsung Techwin Co., Ltd., www.dynatechsmt.com ...... C3 the estimated $270 billion in outsourced Companies entering the EMS model SEHO Seitz & Hohnerleing GmbH, www.sehousa.com ...... 30 value-added logistics services, says Arm- from distribution may underestimate the Siemens Logistics & Assembly Systems, Inc...... C2 www.siplace.com strong Associates, an industry research scope of support services required by Sierra Proto Express, www.protoexpress.com ...... 71 firm. The top 25 have annual revenues of that tailored service package element or SIMCO, www.simco-static.com...... 59 SMT/Hybrid/Packaging 2006, www.smt-exhibition.com ...... 93 about $79.5 billion and are growing at a 6 find that their component purchasing Speedline Technologies, www.speedlinetech.com ...... 11 to 8% annual clip.6 requirements extend far beyond the lines Tamura Corporation, www.tamuracorp.com ...... 69 Large EMS firms such as Celestica, they cover. Plus a big challenge is that Tyco Electronics, www.automation.tycoelectronics.com . . . . 38, 39 Virtual Industries, www.virtual-ii.com ...... 57 Sanmina-SCI and Solectron are using EMS providers make up a large portion VISCOM, Inc., www.viscomusa.com ...... 65 distributors less than before. Their of the total available market for compo- ViTechnology, www.vitechnology.com ...... 63 smaller counterparts – EMS firms below nent purchasing. Vitronics Soltec, www.vitronics-soltec.com ...... 15 $200 million – tend to use a combina- “Many manufacturers reps won’t rep- tion of distributors and direct suppliers. resent EMS providers because they are Advertising Sales OEMs under $50 million are tending afraid of the impact it would have on North UP Media Group, Inc. America: 2018 Powers Ferry Road, Suite 600 toward distributors, including for circuit their sales to EMS providers. Some dis- Atlanta, GA 30339 National Sales Manager: boards. Reason: It does not make sense tributors who dabble in EMS activity to Susan Jones, (404) 822-8900 email: [email protected] for smaller OEMs to spend time buying support some key customers keep that Sales Associate: boards in Asia. very quiet to minimize the fallout from Kamden Robb, (678) 589-8843 email: [email protected] Typical designs built by North Amer- EMS customers. Companies that become Europe: Tony Hill, Lansdowne Media Services Ltd., +44 (0)1442 877777 ican assemblers today are high-end visibly successful as both EMS provider email: [email protected] computers, medical equipment, indus- and distributor may find distribution Asia: Jan Vardaman, TechSearch International Inc., 512-372-8887 trial controls and some automotive sys- sales drying up from EMS customers email: [email protected] Korea: Young Media, 82 2 756 4819 tems. Such products have large and who start to view them as competitors,” email: [email protected] complex bills of materials. Volumes tend says Mucha, founder of Powell-Mucha

66 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Procurement

Consulting Inc. (powell-muchaconsulting.com) and a CIRCUITS Third-Party Logistics Providers Extend Their Global Reach,” Supplychain- ASSEMBLY columnist. brain.com, May 2004. And while the distribution business is characterized by low 7. Rad-Tech company press release, April 2005. margins, some mid-tier EMS companies still have gross margins 8. Rad-Tech company press release, May 2005. of 10% or more. It would be unlikely for companies in such a 9. ELFA company press release, Feb. 7, 2005. position to water those down. With distributors under pressure to grow margins and rev- Mike Buetow is editor in chief of CIRCUITS ASSEMBLY magazine. This article is enues, and with large hurdles (not to mention a poor track adapted from a presentation he gave in September 2004. record) to adding EMS services, it would make sense that they would at least look to the as yet untapped $40 billion PCB market as an area in which to expand. One possible scenario has catalog distributors teaming with a small number of PCB shops (or bare-board brokers) to fill out their line cards. This would put them in position to supply complete BoMs to OEMs. We may have caught a glimpse of this synergy last February, when a Swedish components distributor named ELFA (elfa. se) announced a deal with Elprint (elprint. com), a Norwegian PCB supplier, to offer a single source for components and PCBs. ELFA will sell boards for production of prototypes and ramps, enableing buyers to “use one purchase channel for both components and PCBs.”9 The battleground is coming into focus. Distributors are moving toward more value- added services; EMS firms are doing the same. War – or convergence – is inevitable between the two groups over who wins the OEM’s supply-chain management. Going forward, we can expect EMS firms to remain buyers of PCBs, and some EMS companies will try distribution – and fail. We can expect distributors to retain some in-house EMS work. Mean- while, distributors – mainly catalog types –looking to improve margins and value- added services are a potential customer for PCBs. Some, like ELFA, will get into PCB sales. No doubt, America’s board brokers willbeready. ■

References

1. “Top 35 Global Distributors,” Electronics Supply & Manufacture, May 2005. 2. National Electronic Distributors Association, neda.org. 3. Henderson Ventures, June 2005. 4. IPC October book-to-bill, November 2005. 5. Arik Hesseldahl, ”Stock Focus: Electronics Distribu- tors,” Forbes.com, March 21, 2001. APEX Booth #1898 6. Thomas A. Foster and Richard Armstrong, “Top 25

circuitsassembly.com Circuits Assembly FEBRUARY 2006 67 Solder Joint Reliability

SERIES

Crack Growth Rate Measurement and Analysis for WLCSP SnAgCu Solder Joints

Paresh Limaye, Bart Vandevelde, Dirk Vandepitte and Bert Verlinden

the crack behavior of solder joints as a function of Using FEM, cracking is correlated the imposed strain. Darveaux has provided an extensive range of data for SnPb-based alloys and with average inelastic strain and strain for SnAg.10 This work focuses on crack growth rate measurements of SnAg4Cu0.5. energy density. Test sample. The test sample was a 14 x 7 x 0.68 mm wafer-level chip scale package (WLCSP) redictive models for fatigue life estimation device designed at IMEC. The footprint of the of solder joints are empirical in nature device consists of two 16 x 3 arrays (Figure 1).The P and usually involve a relation between a die was a dummy DRAM memory die manufac- certain damage parameter, for instance, strain tured with IMEC’s Thin Film technology. The energy density or inelastic strain to the experi- structure consists of a 5 µm thick copper layer pat- mentally measured characteristic life. The most terned to form a daisy chain when mounted on common approach averages the damage parame- the PCB. BCB was used as a passivation layer and ter accumulated in the region of the solder joint soldermask, and is opened over the pads to create with the highest likelihood of failure. A variety of soldermask-defined pads. The solder pad pitch is such models exist for SnPb solder joints and to a 0.8 mm and the opening is 0.25 mm. The device lesser degree for Pb-free solder joints.1-4,6,9 What was bumped with 0.3 mm diameter solder spheres has been missing from the picture is an interme- of SnAg4Cu0.5 composition from Umicore Corp. diate set of data, which, although not necessary The bumping process involved applying tacky flux for all empirical models, may shed some light into to the device pad followed by ball placement and

Remove Chip

Remove and Bake

Dip in DyeDip in Liq. Nitrogen

FIGURE 1: Test sample (16 x 6 WLCSP). FIGURE 2: Dye penetration procedure and sample.

68 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Solder Joint Reliability

Table 1. Thermal Cycle Conditions All materials were assumed to be linear elastic in nature Cycle Ramp Up/ Measured Dwell Time Measured except the solder, for which we used the creep behavior model as Down Time Ramp Up/ Setting Dwell Time described by Wiese et al.3 All simulations were performed with 3- Setting Down Time D nonlinear elements. Syed evaluated the use of different solder 0° - 100°C 15 min. 9 min. 15 min. 21 min. creep models and found that most of these models lie within a -40° - 125°C 15 min. 9 min. 15 min. 21 min. narrow band.2 It is further concluded that the models that use -65° - 100°C 15 min. 9 min. 15 min. 21 min. creep only (no plastic flow) can be used with a reasonable corre- solder reflow. The devices were then assembled onto a 1.6 mm lation to the experimental fatigue life. thick FR-4 board with standard surface-mount processes of The measurement of assemblies indicates a variation in the screen print, placement and reflow. The test board consists of 19 devices and can be monitored in-situ in the thermal cycling chamber. The final mount height of all samples was measured and the solder joint standoff estimated from these measurements. A few sam- Flow with the Wave ples were cross-sectioned at various intervals for microstructural evaluation and to mea- Tamura’s Lead Free sure the joint diameter. X-ray image analysis was performed on some samples and the joint Soldering Technology diameter extracted from these images. On average, the joints were 205 µm tall with a standard deviation of 16 µm. Solder joint diameter was 317 µm with a standard deviation of 17 µm. These data sets were used as an input for the finite element modeling. N2 Wave Solder & Spray Fluxer Test procedure. The board was subjected to thermal cycling and two units taken out at Motor-less different intervals, depending on the cycling solder bath, condition and the expected characteristic no moving parts in solder life based on previous experiments. The N2 Reflow Oven bath and 40% less dross interval was approximately 1/6 of the esti- FLIP (Flat Linear Induction Pump) solder mated time to the last failure. Thermal bath technology from cycling conditions are described in Table 1. Tamura makes your wave and selective The cycled device was then placed in a red soldering more reliable dye (Steel Red Dye from Dykem). This dye and cost effective. has sufficiently low viscosity to penetrate the In-line N2 Selective Solder cracks that may have been generated in the Lead-free Wave joint due to thermal cycling. To aid dye flow, Lead-free Reflow • Dross-less Wave Solder in N2 • Independently adjustable air blow speed • Convection air pre-heater the sample is cleaned with acetone and dried • Heater Temp ~= Blow air temp • Built in rapid cooler completely by hot air. The dye was dropped • Best ∆t performance in its class • Lead-free conveyor fingers onto one of the corners and permitted to fill • Lowest N2 consumption end run cost • Easy wave nozzle angle adjustment feature • Catalyst flux separator • Reliable and Repeatable Lead-free Process the region under the device with capillary • Reliable and Repeatable Lead-free Process • Solder bath with patented SP coating action along with an externally applied vacuum (to ensure complete removal of all air). The excess dye was then removed and the sample baked at 90°C for 6 hrs. to cure the dye. Once the dye was cured, the chip was removed from the assembly by means of a Tamura H.A. Machinery, Inc., quick dip in liquid nitrogen and a gentle 9465 Customhouse Plaza, Suite B – San Diego, CA 92154 push on the edge. This ensures easy removal Phone: (619) 661-8275 – Fax: (619) 661-1122 of the chip without damaging the solder Email: [email protected] joint shape (Figure 2). www.Tamura-HA.com Modeling. All the modeling work was performed with MSC Marc Finite Element software. Figure 3 shows the 3-D model.

circuitsassembly.com Circuits Assembly FEBRUARY 2006 69 Solder Joint Reliability

Table 2. Crack Growth Rate Data ------Crack Growth Rate (µm2/Cycle) ------Joint No. 0° - 100°C -40° - 125°C -65° - 100°C 1 117.4 285.3 283.5 2 114.9 248.5 204.9 3 100.7 263.2 195.5 489.5 237.9 166.6 590.1 256.2 190.6 667.5 202.3 186.3 780.3 219.7 156.1 874.8 205.0 152.6 957.3 169.7 158.4 10 76.3 191.6 142.7 11 71.7 172.7 145.9 12 55.3 149.6 124.1

and counts the number of pixels. The pixel count is calibrated FIGURE 3: FE model – quarter symmetry. against images of samples of known lengths taken at the same mag- nification as that of the images of cracked area. Figure 5 shows a solder joint standoff, hence simulations were performed for representative image of the cracked solder joints. three different standoff heights (170, 205 and 240 µm) to estab- Discussion of the crack area of the solder joint specifically refers lish a range of inelastic strain energy densities and strains accu- to the projected area of the actual cracked area onto two dimen- mulated in the critical region of the joint. Figure 3 shows the sions. All measurements in this paper refer to this 2-D projected region from which the inelastic strain accumulated has been area and not the true crack area (Figure 5). True crack surface is a extracted. The mesh density for this region has been also varied very complex 3-D surface and as such difficult to measure. with element thicknesses of 25, 12.5 and 8.3 µm by changing the Darveaux has published the relations between inelastic number of layers in the damage volume. The strain/strain energy density as function region of the solder joint to a distance of 25 µm of crack length. 9,10 An idealized crack from the solder pad is used as the damage vol- area based on this crack length mea- ume. More details regarding the setting up of the surement is used to estimate the crack FE Model with MSC Marc for similar devices are 123 area and relations between strain/strain described by Vandevelde et al.6 456 energy density and crack have also been 789 established. Darveaux also distinguish- Results 10 11 12 es between the primary and secondary Table 2 lists the crack growth rates measured for crack growth rates. In our work, we the outer 12 joints in each quarter of the device focused on measuring the total crack (Figure 4).Based on data collected from the sam- area and have not separated the prima- ples at specific intervals for the different cycling ry and secondary cracks. We believe conditions (a total of 2000 joints were examined: 8 that this approach is valid as both the joints per strain condition x 5 cycle intervals x 12 primary and secondary cracks grow imposed strain values per temp. profile x 3 thermal during the different parts of the thermal profiles), the measured data for crack growth rates cycle and at the end this total crack area were plotted against the estimated inelastic strain will be correlated to the accumulated and strain energy density values (for simulations FIGURE 4: Location key for joint numbers. inelastic strain energy density/ strain using the mean standoff and two layers of elements within a single cycle. in the damage region). The crack growth rates are Each joint is at a different distance from the measured by fitting a linear trend between the mea- neutral point and has a different strain imposed sured area and the number of cycles the sample was per cycle on it. During cycling, the cracking of each subjected to. The linear fit consistently gives the joint is governed by the damage induced, which is best R2 (>0.85) value of all the possible fits. The a function of the strain imposed. Thus, if we can slope of this line is the crack growth rate. This rate estimate the strain imposed on each joint and mea- is estimated for each different strain condition. sure the crack growth rate for each corresponding To measure the crack area on the device pad, joint, we will then have a larger data set for a wider image analysis software UTSCSA Image Tools is FIGURE 5: Typical cracked range of strain ranges/strain energy densities accu- used. This software marks out an area of the image surface. mulated in the joints per cycle. This is precisely

70 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Solder Joint Reliability what has been done in this work. The device has quarter symmetry fixed intervals during the cycling. The time from the first failure and thus there are 24 joints with different strains imposed on to last can occupy as much as 50% of the total fatigue life in the them. By measuring the crack growth rates in all the joints, we can case of the WLCSP (due to the high strains). As samples are theoretically obtain the correlation for a wide range of strains. randomly chosen, there is a probability of choosing a sample However, this approach implicitly assumes that the strain each which may well be at the end of its life or may be only halfway joint experiences remains constant throughout the duration of through its life. Incorporation of this variation in our crack test. In reality, with every temperature excursion, the crack in the growth model is unresolved at the moment but it is easy to see joints grows and the change in assembly stiffness results in contin- that this can give an additional variation in the crack area mea- ual strain redistribution. When one or more joints fail completely, surements. this redistribution increases the strain on the remaining joints by as much as 40%, depending on the proximity to the failed joints and the distance to neutral point. In this study, the measurement was done only to the point where a few outer joints fail and hence we estimate (based of FE simulations of subsequent 4-Layers joint failures) that the imposed strain change lies in the range of 10 to 15%. For inner joints, the total duration of testing may occupy only 10% of the expected At $51 Each, fatigue life of these joints.Given the high standard deviation, especially for the lower crack We Don’t Make areas, it can be concluded that fitting a line for these data points and extrapolating it out- “ wards has the potential for giving erroneous Cheap PCBs, results.In the data presented here,we have not used the measurements for the joints whose total cracked area at the last measurement is We Make less than 30% of the total solder pad area.This reduces the number of usable joints to half. Figure 6 shows a representative plot of the Excellent PCBs— crack growth data for a few joints from the three cycling conditions. Cheap! Variation in measurements. Figure 7 plots the normalized standard deviation vs. the ” measured crack area of the solder joints. The standard deviation is in the range of 0.8 to 1 for the smaller crack areas and decreases with the increasing crack area. This has also been observed by Darveaux for SnPb alloy.10 In general, beyond the crack area of 50% of the total area, the standard deviation drops to 0.2 to 0.3. While this is a rather high value in general, it reflects the reality in a typical assembly. Causes for this variation are Sierra Proto Express numerous but we believe the three main reasons in these particular assemblies are: 1-800-763-7503 Variation in standoff. As reported, the average standoff of the solder joint is 205 µm with www.4LayerPCB.com anormalized standard deviation of 0.06. This translates to an estimated normalized deviation of 0.15 to 0.2 in the estimation of the Buy On-Line NOW! strain and strain energy density values. Sample selection. In the experimental procedure, two samples are taken out at

circuitsassembly.com Circuits Assembly FEBRUARY 2006 71 Solder Joint Reliability

1 1 0.9 0.9

0.8 0.8

0.7 0.7 0.6 0.6 -65+100 Joint 1 0.5 0.5 -65 +100 Joint7 0 +100 Joint 1 ack Area 0.4 0.4 0 +100 Joint 7 Cr 0.3 -40 +125 Joint 1 0.3 -40 +125 Joint 7 0.2 0.2 0.1 Lognormal Standard Deviation of Deviation Standard Lognormal 0.1

Fraction of Cracked Joint Area Joint Cracked of Fraction 0 0 00.20.40.6 0.8 1 0 100 200 300 400 500 600 Fraction of the Joint Area Number of Cycles FIGURE 7: Normalized standard deviation in area measurements vs. FIGURE 6: Crack growth rate plot. fraction of fractured area.

Measurement accuracy. We estimate that although the analysis 1.E+03 software permits pixel measurements and thus can potentially give a linear accuracy of ~5 µm, the area measurement accuracy is around 1000 sq. µm. /Cycle) 2

Crack growth rate analysis. The relation between the crack m growth rate and the inelastic strain/strain energy density is typi- µ cally described with a power law 1.E+02

dA/dN = C1( )n1 (I) k Growth Rate( dA/dN = C2(∆W)n2 (II) Crac 2 where dA/dN is the crack area growth rate expressed in mm , 1.E+01 C1,C2 are constants, n1,n2 are exponents fitted to the data, is the 1.E-02Inelastic Strain (/) 1.E-01 average accumulated inelastic strain in damage volume over a sin- FIGURE 8: Inelastic strain vs. crack growth rate. gle cycle and ∆Wisthe accumulated inelastic strain energy density in damage volume over a single cycle.10 Figures 8 and 9 are the plots of the crack growth rate vs. inelastic strain and strain energy between 1.1 to 1.25 for strain correlation. The correlation factor density respectively for the standoff height of 205 µm and for two (R2)for all the cases lies in the range of 0.85 to 0.9. layers of elements in the damage volume.Table 3 lists the constants Fordevices with such high strain values, crack initiation occurs for different element thicknesses/mesh densities used in the finite early on in the cycling. Zhang et al11 have shown that for WLCSP element simulations. In all cases, the exponent values lie in the devices, the crack initiation occupies a very small part of the total range of 0.95 to 1.05 for strain energy density correlation and fatigue life.Time zero analysis of the devices does not show any ini-

1.E+03 /Cycle) 2

1.E+02 Crack Growth Rate (µm Rate Growth Crack

1.E+01 1.E+00 1.E+01 Inelastic Strain Energy Density(MPa)

FIGURE 9: Inelastic strain energy density vs. crack growth rate. FIGURE 10: Cross-section of a partially failed joint.

72 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Solder Joint Reliability tial cracking but if the crack growth rate plots are extrapolated •The normalized standard deviation for measured crack area is backward, one can see that this initiation takes place within the high (0.8 to 1.0) for the lower crack areas, drops with increasing first few cycles. Hence in this study, we have not provided any cor- crack area and settles down to a value in the range of 0.2 to 0.3. relation for the number of cycles to crack initiation. •Power law fitting with the inelastic strain and strain energy den- Microstructural evaluation. Thermally cycled samples were cross- sity provide a reasonable goodness of fit (R2~0.8 and higher). sectioned and analyzed with the aid of polarized light. Figure 10 The estimated strain and strain energy density values for the shows a cross-sectioned joint after 480 cycles of 0° to 100°C. Look- joints depend on the solder material model used and also on the ing closely in the region of the fracture crack, the most striking fea- element mesh size. We have provided these correlations for a ture is the average grain size. Significant recrystallization has taken certain range of element sizes. place in the region around the crack and also in front of the crack tip (Figure 11).This recrystallized zone extends to a region of 25 to 30 µm from the die pad. The average grain size in the recrystallized zone is around 10 µm. This has also been observed by Henderson7 and Reinikainen.8 Figure 11 shows SEM images of a device cycled in –40 to 125°C for 100 thermal cycles. Note that this sample was MVP AOI not opened by dipping in liquid nitrogen but was simply sheared off, thus the images are performance solutions... representative of the actual fracture conditions. The fatigue crack zone is readily distin- One Platform guishable with the recrystallized grains (Fig- ure 12).Fatigue crack striations can also be Multiple Capabilities seen on the individual grains (Figure 13). Henderson8 et al have explained this crack True Flexibility growth mechanism as a combination of recrystallization of the grains enhancing the grain boundary sliding resulting in intergran- ular fracture. This has also been reported in the literature for high strain loading conditions.12 Intermetallic separation is seen in Continuous Innovation some fractured samples but these occurrences Industry Leading are random and form a small portion of the Flexible Solutions overall measurements. Performance Leader Conclusions MVP continues to lead performance Ease of use We have attempted to measure the crack in the AOI industry with it’s growth rate in SnAgCu solder alloy. We mea- innovative and flexible range of Flying Color Technology sured these data for a wide range of strains new products which include metrology focused inspection Multiple Capabilities from a single device. These assemblies were platforms, providing additional subjected to three different thermal cycles. capability for wirebond and Wirebond •The crack growth data in the strain range die-placement as well as their Die-Placement of 0.02 to 0.1 (volume averaged) and a new Flying Color technology. strain energy density range of 1 to 5 MPa Precision Metrology has been presented here. Due to the vari- MVP also introduces it’s iPro Dynamic Process Control ation in solder joint height in the assem- interface which brings the ease of bly, these data have been correlated to a use and set up of image comparison range of strain values with a probabilistic systems to the rules based, distribution. performance leading marketplace. •For a vast majority of the joints examined, the fatigue crack was ductile. In www.machinevisionproducts.com ® Visit us at APEX booth some instances intermetallic separation ® number 2493 1-800-260-4MVP occurred, but their extent and frequency and the DESIGNERS SUMMIT was low.

circuitsassembly.com Circuits Assembly FEBRUARY 2006 73 Solder Joint Reliability

•Microstructural analysis reveals that the region under highest Table 3: Fitted Constants for Crack Growth Rate Correlation strain shows severe recrystallization. This recrystallization Strain ( avg) occurs ahead of the crack front. The damage volume used to Element Average C1(10-3 mm2/n1 extract data from the FE Models is taken to be the zone where Thickness Element Cycle/(mm/mm)n) (mm) Volume recrystallization is seen, in the range of 25 to 30 µm. (mm3) The correlation data published here should be used with 2.50E-02 4.38E-05 4.3±1.2 1.10 some caution because they are generated from a creep-only sol- 1.25E-02 2.19E-05 4.58± 0.9 1.22 der material model. Moreover, the strain ranges are on the high- 8.33E-03 1.46E-05 4.45± 0.9 1.23 er end of typical applications and the validity of extrapolating Strain Energy Density (∆Wavg) -5 2 2 this to lower strain values is unknown. Given the nature of the Element Average C2(10 mm /n test device, loading the solder joints takes place in more or less Thickness Element Cycle/MPan) Volume pure shear condition. These data may be used for devices that 2.50E-02 4.38E-05 6.14± 0.48 0.96 operate in high strain ranges and with the use of appropriate 1.25E-02 2.19E-05 4.3±0.18 1.05 damage volume. The damage volume chosen should be the 8.33E-03 1.46E-05 4.06±0.18 1.05 recrystallization zone in the solder joint, as has been done in this work.In future, more measurements will be conducted on spe- 6. B. Vandevelde, M. Gonzalez, P. Limaye, P. Ratchev and E. Beyne, “Thermal Cycling cially designed test vehicles and also for lower imposed strain Reliability of SnAgCu and SnPb Solder Joints: A Comparison for Several IC-Packages,” values and the data presented here will be updated. ■ EuroSimE 5th International Conference, pp. 565-570, May 2004. 7. D. W. Henderson, et al, “The Microstructure of Sn in Near-Eutectic SnAgCu Alloy Sol- der Joints and Its Role in Thermomechanical Fatigue,” J. Mater. Res., vol. 19, pp.1608- Acknowledgments 1612, June 2004. The authors would like to acknowledge the valuable assistance of Peter Ratchev 8. T. O. Reinikainen, et al “Deformation Characteristics and Microstructural Evolution of and Nele Van Steenberge for the analysis of samples and Prof. Dr. Jozef Van Dyck SnAgCu Solder Joints,” EuroSIME 6th International Conference, May 2005. 9. R. Darveaux, “Effect of Simulation Methodology on Solder Joint Crack Growth Cor- for interesting discussions regarding statistical analysis. We would also like to relation,” Electronic Components and Technology Conference, pp. 1048-1063, 2000. acknowledge the support of the ALSHIRA Project sponsored by IWT Flanders, Bel- 10. R. Darveaux, “Crack Initiation and Growth in Surface Mount Solder Joints,” ISHM gium (imec.be/ALSHIRA), Olivier Hutin and Stefan Merlau of Umicore Corp. for International Symposium on Microelectronics, pp. 86-97, November 1993. providing SAC solder spheres and Alcatel Bell, Geel for assembly support. 11. L. Zhang, R. Sitaraman, V. Patwardhan, L. Nguyen, N. Kelkar, “Solder Joint Reliability Model Vath Modified Darveaux’s Equations for the Micro SMD Wafer Level-Chip Scale Package Family,” Electronic Components and Technology Conference, pp. 572-577, References May 2003. 1. R. Darveaux, K. Banerji, A Mawer and G. Dody, “Reliability of Plastic Ball Grid Array 12. A.R. Syed, “Thermal Fatigue Reliability Enhancement of Plastic Ball Grid Array (PBGA) Assembly,” Ball Grid Array Technology, McGraw-Hill, 1995. Packages,” Electronic Components and Technology Conference, pp. 1211-1216, May 2. A. Syed, “Accumulated Creep Strain and Energy Density Based Thermal Fatigue Life 1996. Prediction Models for SnAgCu Solder Joints,” Electronic Components and Technolo- gy Conference, pp. 737-746, June 2004. This article was presented at SMTA International in September 2005 and is used 3. S. Wiese, et al, “Microstructural Dependendence of Constitutive Properties of Eutec- with permission of the SMTA (smta.org). tic SnAg and SnAgCu Solders,” Electronic Components and Technology Conference, pp. 197-206, May 2003. 4. A. Schubert, et al, “Fatigue Life Models of SnAgCu and SnPb Solder Joints Evaluated Paresh Limaye is a researcher at IMEC (imec.be); [email protected]. by Experiments and Simulations,” Electronic Components and Technology Confer- ence, pp. 603-610, May 2003. Bart Vandevelde is section leader and senior scientist at IMEC. Dirk Vande- 5. Q. Zhang, et al, “Viscoplastic Constitutive Properties and Energy-Partioning Model of pitte and Bert Verlinden are professors of engineering at Katholieke Univer- Pb-free Sn3.9AgCl.6Cu Solder Alloy,” Electronic Components and Technology Con- siteit (kuleuven.ac.be). ference, pp. 1862-1868, May 2003.

FIGURE 13: SEM analysis of fractured region, showing fracture striations on grains.

FIGURE 11: SEM analysis of fractured region. FIGURE 12: SEM analysis of fractured region.

74 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Perfectly READY

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® Pb-Free Wave Soldering

Dynamics in Pb-Free Wave Soldering

R.A. Szymanowski, D. Casati, E. Saglia, P. Lotosky, K. Howell and G. Hueste

always been affected by numerous variables. An in-depth study of how three Pb-free When solutions address the complete process, rather than a single point, the corrective action alloys performed. Also evaluated: flux can be most effective. The primary goal of this work was to bring the selection and convection preheat. Pb-free wave solder process to a higher level of performance, to meet demands of boards that are Ed.: For the full article, please visit circuitsassembly.com/cms/ bigger, thicker, heavier, with more thermal chal- content/view/2710/ lenge, more density and demanding a no-clean process. s we consider the rapid improvements in Our work focused on wave solder challenges SMT and the perception that wave solder anticipated in heavier boards, looking at the A has not shown the same rate of improve- process attributes of flux, preheat and alloy. If the ment, note the following three considerations: study focused on thinner product, existing mate- •Resource focus was initially directed to SMT rials and processes were seen as adequate. primary attach, not wave solder. The strategy was to begin with the confirma- •Wave solder is significantly more complicated tion of a flux. Because preheat was identified as a and subject to more variability than reflow, significant factor in soldering thick, thermally complicating straight-forward, universal solu- challenging boards, a test of preheat performance tions. was planned. Alloy characteristics would then be •Beneficial design changes to wave solder studied, primarily by using designed experiment process equipment lags the reflow process methods, followed by small confirmation runs. equipment. Current knowledge would focus efforts and opti- Logical and accurate studies of wave soldering mize the design of experiments. are now being pursued. Wave soldering has The approach came from considering the following known conditions: •While alloys may change, the fundamental rules of soldering do not. To form a solder joint requires surfaces that are prepared for the solder process and meet some time-to- temperature relationship. •The wetting speeds and forces of Pb-free alloys are identified; compared to SnPb, it takes longer to make the same solder joint. •Considering the components used in the manufacture of a flux, there will be thermal degradation if their time-temperature balance is FIGURE 1: Final wetting angle. exceeded.

76 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Pb-Free Wave Soldering

•Copper dissolution in the board is possible with extended Phase 4 consisted of machine testing Alloy B (SAC305), con- contact times in SAC alloys. figured to Machine B equivalent, with the same conditions as •Considering the laminate and components on soldered Phase 3. assemblies, there is also the potential for thermal degradation Phase 5 consisted of visual and production scope inspection, if a time-temperature balance is exceeded. and x-ray inspection to verify hole-fill as required. • Pb-free alloys have a smaller superheat. (Superheat is the dif- Phase 1. A solder alloy pellet was put onto a copper coupon,

ference between alloy melting point and process temperature covered with 10 micro-liters of flux, then reflowed in N2 atmos- and distinctly affects the time it takes to make any solder phere. The melting process is constantly monitored by a video joint.) The typical superheat for a SnPb process is 67° to 77°C. system that permits observation of the alloy profile. The “contact In Pb-free alloys, depending on the alloy used it can be as low as 23°C, and probably not more than 44°C. In the context of soldering thermally challenging and thick board assemblies: •Flux spread and wetting is required. •Flux performance and survival after longer solder contact times is required. •Flux performance and survival in hotter, longer preheats is an advantage. •A full solder joint will not be formed if a minimum temperature-to-time point is not reached. If a lower pot temperature is used, a higher preheat is required. If a higher pot temperature is used, preheat can be lower. If contact time can be extended, lower preheat and pot temperatures are possible. •The laminate and components impose limitations on the above. •Some characteristics of the alloy affect process yield. •There are no independent variables.

Experiment Descriptions Flux testing. Flux testing was required as a mandatory building block for the following work and had five major parts. Phase 1 consisted of testing all flux candidates in a laboratory wetting capability test, thereby reducing the number of candidates to test more extensively in machine systems. Phase 2 consisted of machine testing Alloy A (SAC405), Machine A: •Flux application rate and preheat at vendor recommendation. •Vary contact time to a maximum of 8 sec. •Vary pot temperature from 250° to 275°C. •The population of flux candidates is expected to be reduced due to Phase 1 comparisons and elimination of weaker candidates. Phase 3 consisted of machine testing Alloy B (SAC305), Machine B; flux application rate testing as before and at a lower rate; and varying contact time and temperature as above.

circuitsassembly.com Circuits Assembly FEBRUARY 2006 77 Pb-Free Wave Soldering

FIGURE 2: Wetting index data. angle” after 20 sec. from beginning of melting is considered. Ini- activator along the board surface. The IFT of VOC fluxes has tial and final situations are reported. Figure 1 shows the final been measured by Pendand drop. wetting angle of one sample. Phases 2-4. In machine testing of fluxes, the experiments were To approach a “standard surface,”coupons were treated as fol- similar in that they are searching for both flux performance and lows: flux survival. They differed in machine description and alloy. The •Degrease with Acetone (ACS grade). general customer base may chose either a SAC305 or a SAC405 •Treat in HCl solution 15% for 15 to 20 sec. alloy. Within the company, two different machines comprise the •Rinse with DI water. defined base for Pb-free work.

•Dry under compressed N2 flow. Some indications of the difference in performance due to the Surface roughness and morfology can heavily affect the alloy are addressed in the next part of the experiment, which results, thus the same type of copper-clad laminate (CCL) was looks specifically at solder alloys. used for all fluxes.The treated copper surface of the CCL used in In Phases 2, 3 and 4, the machine setup was always optimized this work was evaluated by AFM. and confirmed as good. In all cases, it was a double wave process. The wetting capability of flux is reported with a number, scale Any parameter outside the DoE was made as uniform and con- 0-100, defined here as “wetting index” (Figure 2).It is simply the trolled as possible. These phases of testing are designed to take the cosine of the “contact angle” (multiplied by 100). limited population of flux candidates and rank their performance. Table 1 (online) shows the specific structure of the Phase 2 e.g.: Contact angle = 44 ° ➔ “Wetting Index”: cos 44 x 100 DoE. Phase 2 testing was conducted with a SAC305 alloy and a standard Pb-free solder module configuration. Cos 44° = 0.72 Phase 3 testing continued to look at flux performance and 0.72 x 100 = 72 wetting index survival, but the amount of flux applied was significantly reduced to further stress the material. Table 2 (online) shows the The higher the wetting index the better the wetting. A wetting specific structure of the Phase 3 DoE. Phase 3 testing was con- index of 100 equals ideal wetting. It is possible that only the wet- ducted with a SAC305 alloy and an enhanced Pb-free solder ting angle by itself could be recorded, but another advantage in module configuration. using the cosine of the wetting angle is that it is used in formu- Phase 4 testing continued to look at flux performance and las to extact the “Work of Adhesion,” or “Wa.” survival. The amount of flux applied was significantly reduced, Surface tension or interfacial tension (IFT). IFT of liquid flux can to further stress the material. The wave forms were changed to play an important role in the soldering process. The IFT of alco- duplicate the machine in Phase 2. Table 3 (online) shows the hol-based flux is mainly dictated by alcohol; the IFT of IPA is specific structure of the Phase 4 DoE. Phase 4 testing was con- around 22 mN/m. The IFT of water is significantly higher: 72 ducted with a SAC305 alloy and the standard Pb-free solder mN/m. This high IFT would not permit flux to work properly. module configuration. Surfactants are usually added to the VOC-free flux formulation Phase 5. In the given project, questions of alloy acceptabili- to lower the IFT. ty or voiding were not a subject of investigation or discussion. The lower the flux IFT the higher its capability to spread Consequently, microstructure analysis has minimal value in through holes. Conversely, low IFT could favor the dilution of this work.

78 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Pb-Free Wave Soldering

The majority of analysis is visual inspection and inspection online).The correlation of conveyor speed to contact time was: under production scopes. Hole fill, solder balls, solder bridges, 1.75 fpm = 7.5 sec. of contact time; and 4.5 fpm=3sec.ofcon- excess solder, cosmetics and joint shape per IPC-A-610D are tact time. applied. Cosmetics are a secondary issue, compared to first-pass The confirmation run was performed at the setting of best yield, given approximately the same visual appearance. yield, based upon field inspection of the collection of DOE sam- Ed.: For space, the discussion of solder machine preheat testing ples. Confirmation runs include OSP and Pb-free HASL boards. is online. In the analysis of samples, visual inspection recorded solder shorts,excess solder,insufficient solder and hole-fill by component Alloy Impact on Process type. Solder balls were reported for the entire board. Cosmetics The consideration of different Pb-free alloys for wave soldering raises the question of how the alloy impacts the process. In a similar vein, as production moves from alloy A to alloy B, it would be valuable to know Keep it up and Keep it down: how much process knowledge is transferable between these alloys. These are the points Eunil Provides high productivity that drove this experiment section. The goals for this section were to stan- and low cost solution dardize the entire wave solder process, and manipulate only pot temperature and pre- Eunil H.A. Americas Expends its Business to AOI, heat, for three Pb-free alloys. The alloys studied were SAC405, SAC305 and a propri- Screen Printer, and Custom Automation Solutions. etary low-silver SAC alloy. After measuring the defect rates from the different DoE steps, a limited confirmation study was run. The DoE work and confirmation work data were then compared. The equipment included a wave solder HV-5000LC - Inline AOI machine (manufactured in Feb. 2005). The solder module configuration included tur- bulent and smooth wave forms. The solder module was a “roll-out” assembly permit- AOI solutions: Nexscien ting for easier alloy changes, and it was the Inline Color AOI, Desk-top only change that occurred between alloy color AOI Equipment: •Total inspection solution tests. The solder nozzle assemblies were the • Low cost solution same in all cases. They were moved to the • Ease of programming •High quality soldering joint ELM-700A alloy pots and reinstalled to exact parame- inspection with ILA (Intelligent Laser Marking system ELVD-500 Level Analysis) ters by use of hard tooling. The flux module • WYSIWYG Program concept Magazine Vacuum Loader Customized Factory (What you see is what you get) was a traversing head spray unit. The con- Automation Systems: www.nexscien.com veyormodule was a variable speed finger Eunil Americas SMT • Odd Parts Insertion Equipment Process & Inspection • PCB Depaneling Equipment conveyor. Solutions: • Label Attachment Equipment Test and analysis materials and equipment • Most cost competitive • Laser Marking Equipment •High reliability •Plasma / LCD / TV Final included an ECD Super Mole Gold; 30 AWG, • Compact design Assembly Line type K T/C; aluminum, Kapton and high- •High speed magazine changeover solution temperature solder for T/C attachment. DSP-3800V PLUS Test Vehicle A was 0.062" thick x 6" x 8" Vision Screen Printing Machine with four test components (two DIMM con- With 2D Inspection Function nectors at C3, C2; 0.100" grid at C1, with leg-stick-out under 0.050"; 0.100" grid at C4, with leg-stick-out near 0.125"); three T/C spaced uniformly across diagonal for profil- EUNIL H.A. AMERICAS, INC., ing. TVA had two internal layers of 3 oz. 9465 Customhouse Plaza, Suite B - San Diego, CA 92154 copper, with 0.5 oz. surfaces. Phone: (619) 661-8275 - Fax: (619) 661-1122 Email: [email protected] Test outline. The test matrix was a simple, www.eunil.com three variable DoE format (Table 6,

circuitsassembly.com Circuits Assembly FEBRUARY 2006 79 Pb-Free Wave Soldering

Table 7. Topside vs. Opposite Bottomside Heater Table 8. Preheater Study of Convection Bottom with Convection Top S.P. Bottom S.P. Top Actual – Bottom Actual – Top S.P. Bottom S.P. Top Actual – Bottom Actual – Top 200 100 201 128 120 60 119 200 120 200 120 120 80 120 200 140 200 138 120 100 120 200 160 200 161 120 120 120 200 180 200 180 120 140 120 200 200 200 200 120 160 120 200 220 200 217 120 180 121 200 240 201 238 120 200 124 200 260 200 260 120 220 Not a valid setting Not a valid setting 200 280 199 281 100 200 127 200 200 300 201 303 120 200 127 201 200 320 200 320 140 200 140 200 500 340 223 340 160 200 160 200 480 400 502 400 180 200 179 201 460 400 480 399 200 200 201 199 300 400 459 401 Temperatures in °C. 300 100 307 151 300 120 Skip Skip gave results measurably better than the standard configuration, 300 140 301 164 and flux residues were less obvious. 300 160 300 175 In the VOC-free, no-clean flux formulas, the resistance to 300 180 300 188 bridges was slightly less than the VOC category leader, but cos- 300 200 300 200 metics were generally better. Temperatures in °C. Preheater study. This preliminary study showed that paired convection preheaters perform better than an IR-convection pair. were noted for the assembly.A Nicolet Imaging NXR-1400I system Paired (a term used to identify a topside preheater located direct- was used for hole-fill confirmation. The reference settings: power ly above a similar bottomside heater) convection preheaters operat 30; KVA at 80-110; board held at a constant 45° angle. ated with good predictability and excellent efficiency. The indi- Results were interpreted with IPC-A-610C and IPC-A-610D; x- vidual top convection heater was superior to the individual top IR ray; main effect plots of DoE and confirmation runs; box plots as heater. When used prior to a paired set of IR preheaters, the net above; one way ANOM as above; and interaction plots as above. effect was superior to a single top-side IR preheater. Table 7 shows the influence of a topside heater vs. the oppo- Results site bottomside heater in achieving and holding set-points. Flux evaluation. A VOC no-clean formula with 6% rosin exhib- Table 8 shows the influence of top heater vs. bottom heater in ited the fewest solder defects and moderate flux residue. There achieving and holding set-points. was no discernable difference when used with either SAC305 or Figure 3, a representative profile of a top convection pre- SAC405. (The flux selection work was performed with only two heater, shows a rapid and uniform effect on the board, with a alloys.) Performance was uniform across all temperatures and minimal temperature difference across the panel. Set-point tem- contact times. The enhanced Pb-free wave solder configuration peratures were approximately 50% of IR.

FIGURE 3: Representative profile of a top convection preheater. FIGURE 4: Representative profile of a top IR preheater.

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Figure 4, a representative profile of a top IR preheater, shows a slower and nonuniform effect on the board, with a wide temperature difference across the panel. Set-point temperatures were approx. double that of the convection system. Alloy study. In the course of the study, there was a reoccurring situation with large voids, especially in a single drilled hole size. FIGURE 6: Microsection view of a void found dur- FIGURE 7: Exploded view of wall imperfection It was explored, and the following the study. causing the void shown in Figure 6. ing is presented as points for future study of bare board quality standards, MSL of bare boards Alloy Pot Temperature and process parameters. 10 In summary, a minor imperfection in a PTH, in conjunction 9 with a hydroscopic laminate, and a solder contact time over 3 8 sec., at a 265°C pot temperature, resulted in large voids. Figures 7 5 (online), 6 and 7 show the existing standard per IPC-A-610, 6 and a sample void found in the study. 1 2 3 250 265 Conveyor Speed Pre-Heat Figures 8 to 11 (and 12 to 24, online) show a statistical repre- 10 9 sentation of the alloy interaction study. Balls Solder of Number of 8

Mean 7 Conclusions 6 The flux evaluation methodology was successful for the con- 1.75 4.40 90 130 ditions applied. A large field of candidates was put under evaluation, increasing the opportunity to find the most appropriate FIGURE 8: DoE main effect plots (data means) for solder balls. candidate; the laboratory test process reduced the field of candidates quickly, with low cost, and was both impartial and repeat- lower delta t than the alternative methods; 3) convection heaters able; a minimum number of test vehicles was required for actu- are less sensitive to color or thermal mass. Given the study detail al machine work; the machine time used for the testing was and results, top convection heaters are identified as a process short; the program can be modified to suit business needs. advantage. For preheat, given the rules of solder joint formation that The alloys tested were: SAC405 (Alloy 1), SAC305 (Alloy 2) demand a time-temperature threshhold to be met, the perfor- and a proprietary, low silver SAC (Alloy 3). The ANOM charts mance improvements seen in the test are desirable. Compared to (Figures 25 to 27, online) of the excess solder data show, except other preheaters, the set-points on the convection unit are gen- for one point, the study results to generally be within the antici- erally lower. From the profiles, three attributes in convection pated range of statistical error. In effect, this supports the state- heaters were noted: 1) the assembly reacts to the thermal energy ment that there is not a significant difference in the process char- more quickly; 2) in a shorter period of time, the assembly has a acteristics of each alloy.

50 BD ID Alloy DOE Runs

20 40 15 30 10 lder Balls

5 20

of Solder Balls Solder of 1 2 3 4 5 6 7 8 9 10 1 2 3 10 Board Finish Numb e r o fS o 20 0

Pre-Heat 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 15 9 3 9 3 9 3 9 3 9 3 9 3 9 3 9 3 9 3 9 3 9 3 9 3 1 1 1 1 1 1 1 1 1 1 1 1 Conveyor Speed 5 0 5 0 5 0 5 0 5 0 5 0 Mean ofNumber .7 .4 .7 .4 .7 .4 .7 .4 .7 .4 .7 .4 10 1 4 1 4 1 4 1 4 1 4 1 4

Pot Temperature 0 5 0 5 0 5 25 26 25 26 25 26 5 Alloy 1 2 3

LF HASL OSP FIGURE 10: DoE box plot for solder balls vs. preheat, conveyor speed, FIGURE 9: Confirmation run main effect plot. pot temperatures and alloy.

82 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Pb-Free Wave Soldering

Table 9. Confirmation Run, Non-Solder Ball Defects 50 Data Alloy 1 Alloy 2 Alloy 3 Grand Total 40 Sum of Shorts Pins on C3 DIMM 0303

30 Sum of Shorts Pins on C2 DIMM 99018 lder Balls Sum of Shorts Pins on C1 26 12 16 54

20 Sum of Shorts Pins on C4 0000

Subtotal Shorts 35 24 16 75 10 Nu mb e r o f S o Sum of ES C3 DIMM 0202 0 Sum of ES C2 DIMM 1102 BD ID 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 1 1 1 1 1 Sum of ES C1 7 10 8 25 Board Finish L P L P L P S S S S S S A O A O A O H H H F F F Sum of ES C4 0101 L L L Alloy 1 2 3 Subtotal Shorts 8 14 8 30 FIGURE 11: Confirmation run box plot for solder balls based on board Sum of No. of Defect Pins C3 0000 for Hole Fill finish. Sum of No. of Defect Pins C2 0000 for Hole Fill In Figure 25, the response in OSP is the single point that does Sum of No. of Defect Pins C1 0000 not follow the trend. For those test conditions, it cannot present- for Hole Fill ly be explained. All samples were the same lot, and the same OSP. Sum of No. of Defect Pins C4 0000 for Hole Fill An extended study is suggested. Presently, a single, small study Subtotal Shorts 0000 cannot be considered a process standard. While one ANOM chart supports no statistical difference Table 10. Confirmation Run, All Defects. between alloys, the analysis of main effects and interactions for Data Alloy 1 Alloy 2 Alloy 3 Grand solder balls and hole-fill are of interest. Total •The low-silver SAC alloy generally had the best performance. Sum of No. of Solder Balls 112 320 48 480 •When the main effect plots are reviewed, the line slopes clear- Sum of Shorts Pins on C3 0303 ly suggest the stronger process set-points. As an example, for Sum of Shorts Pins on C2 99018 any given alloy, the confirmation run set points were deter- Sum of Shorts Pins on C1 26 12 16 54 mined by the best DOE set-points. Sum of Shorts Pins on C4 0000 •All alloy confirmation runs were the same set-points for pre- Sum of ES C3 0202 heat, conveyor speed and pot temperature. Sum of ES C2 1102 •For hole-fill, there were no defects in any confirmation run. Sum of ES C1 7 10 8 25 The large voids found unexpectedly in this study may be asso- Sum of ES C4 0101 ciated with bare board specifications that are not adequate for Sum of No. of Defect Pins C3 0101 Pb-free wave solder. for Hole Fill •The voids could be eliminated by holding contact time under Sum of No. of Defect Pins C2 0000 for Hole Fill 3 sec. Sum of No. of Defect Pins C1 0000 •That situation is commonly violated in current SnPb work. for Hole Fill •An industry effort will be the required corrective action on Sum of No. of Defect Pins C4 0000 this problem. for Hole Fill As unexpected as the voids were, another unexpected finding Total 155 358 72 585 was the total lack of defects on C4. C4 was a 0.100" grid pin head- er. The through-board stick-out was purposely made very long, temperature; process characterization in board thicknesses over to 0.175", to encourage solder bridges. There was never a bridge 0.135", with mixed component loading and variations in thermal on this connector, while there was often a bridge on the exact mass; a comparison of selective soldering machines, with Pb-free same part that had a stick-out of about 0.050". In another study, alloys, to the optimized Pb-free wave solders. ■ the leg stick-out was about 0.090", and bridges occurred. In discussion, there are other ways to interpret this study, and Ed.: This article was first published at IPCWorks in November 2005 and is used one is to look at all test conditions, and make an alloy selection here with permission of the authors. based on the alloy with the largest number of test runs that have few defects. This logic suggests that Pb-free HASL surface finish- Richard A. Szymanowski,senior process developing engineer, D. Casati and E. es may have a place in Pb-free wave soldering. Saglia are with Celestica Corp. (celestica.com). Paul Lotosky is global director, Future work will include a study of defects by alloy and surface technology implementation at Cookson Electronics (cooksonelectronics.com); finish, with larger sample sizes; explanation of the large voids [email protected]. Keith Howell,product marketing manager, formed after exceeding a minimum contact time and solder pot and Gregory Hueste are with Speedline Technologies (speedlinetech.com).

circuitsassembly.com Circuits Assembly FEBRUARY 2006 83 Soldering Tips XRF, Close Up X-ray fluorescence is a quick, efficient tool to ensure RoHS compliance.

ith the selection of Pb-free solder alloy XRF can be used to precisely identify and quantify the replacements for SnPb coming into focus, presence of the EU’s banned substances. It is by no W much of the recent discussion about the Pb- means limited to this function, however. A traditional free transition has been about demonstrating compli- use for XRF is the measurement of plating thickness. ance. The European WEEE and RoHS directives define XRF can efficiently and precisely measure surface finish specific amounts of toxic materials permitted for use in thicknesses. It can also be used for process control, electronics equipment. Conforming to the legislation incoming material quality control and qualification of may require quantifying the amount of the banned sub- components, assemblies and processes. Other uses stances in solder joints, components, connectors, board include measurement of metal films using plating, materials and the completed assembly. deposition, sputtering and ion plating. The need to efficiently identify banned substances in One side effect of the transition to Pb-free products plastic, ceramic and metallic materials has increased has been unexpected changes to component surface fin- interest in elemental analysis techniques such as x-ray ishes. Manufacturers will alter component finishes with- fluorescence (XRF). This non-intrusive, nondestructive out notification. In some cases, changes in component measurement method has been used in electronics man- surface finish composition were identified from one lot ufacturing for years, primarily to measure the composi- to the next. Such variations can result in changes in wet- tion and thickness of surface platings and coatings. ting performance, storage life, process efficiency and sol- Recent strides in XRF technology have improved the der joint reliability. Technical assistance from manufac- equipment’s efficiency, precision and cost of ownership, turers and distributors to identify the surface finish on a making elemental analysis by x-ray fluorescence a popu- lot-by-lot basis can be difficult to obtain. Quite often, lar tool for detecting the presence of banned metals. data sheets do not include surface finish information. Unlike the more common transmission x-ray imag- Using XRF to screen incoming lots of components for ing, XRF analyzers are used strictly for obtaining ele- surface composition can prevent the detrimental effects mental information. XRF analyzers do not use x-rays for of unknown changes to the surface finish. imaging. XRF uses the x-rays from an excitation source Some DoD and NASA contractors are using XRF to (either an x-ray tube or radioactive source) to produce mitigate tin whisker risk by mandating at least 3 wt. % an incident beam. As x-rays contact the sample surface, Pb in Sn-finished components. Studies have shown that they are either absorbed by or dispersed through the Sn-based finishes with 3% Pb or more have a signifi- surface atoms. A photoelectric effect occurs when the x- cantly reduced risk of forming tin whiskers as com- rays are absorbed into the atoms. The x-ray transfers its pared to pure tin finishes. Thus DoD contractors and energy to the inner shell electrons of each atom, thereby other companies exempt from the EU directives require ejecting the electrons and creating a vacancy in the at least 3% Pb finishes from component suppliers. XRF atom’s inner electron shell (Figure 1). Electrons from the can screen incoming product finishes for Pb levels. In atom’s outer shell then stabilize the atom by filling in the the case of one contractor, the EMPF laboratory evalu- inner shell. This electron movement results in energy ated every metallic surface on the assembly, including differences that produce x-rays. discrete components, ICs, transistors, screws, connec- XRF detectors absorb these x-rays and measure their tors, nuts, bolts and eyelets. energies. Each individual element produces x-rays with a unique set of energies. XRF spectrometers use x-ray The American Compet- detector elements [Si-PIN, Si(Li) or Ge] to create a itiveness Institute spectrograph that shows all the elements detected. This (aciusa.org) is a sci- technique is similar to energy dispersive spectroscopy entific research corpo- (EDS), an elemental identification technique com- ration dedicated to the monly coupled with scanning electron microscopy advancement of elec- (SEM). Unlike EDS, however, XRF can be performed in tronics manufacturing normal atmospheres and does not require an expensive processes and materi- vacuum pump system. als for the Department of Defense and indus- XRF Applications FIGURE 1: X-rays are produced by the movement of elec- try. This column Much like transmission x-rays, XRF has an equal trons. XRF detectors absorb these x-rays and measure their appears monthly. number of production and analytical applications. energies.

84 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Soldering As the Pb-free transition initiates the demise Tips of SnPb board finishes, it simultaneously pro- motes interest in alternative board surface finishes. Electroless nickel immersion gold, Courtesy: Fisher immersion tin, immersion silver and organic solderability preservative are market leaders for SnPb replacement. While each has its own advantages and disadvantages, none will perform properly if the thickness of the plating is not controlled. With the exception of OSP finished boards, the plating thickness of incoming lots of bare boards can be recorded prior to the first run build using XRF. Wave solder contamination is another issue FIGURE 2: A screenshot of an XRF output showing the RoHS spectrum. associated with the Pb-free conversion. Solder pots that contain high-Sn alloys such as SnAg, SnAgCu 40%. Rarely are components finished with 97% Sn and and SnNiCu must be monitored for solder pot corro- 3% Pb finishes. A standardless reading of tin and Pb over sion. This corrosion can occur due to the solder pot lin- copper may yield as low as 0.25% error; therefore, a stan- ing composition, copper dissolution from the board dardless reading that returns 5% Pb with 0.25% error has and components, or cross-contamination of Pb and Pb- sufficient precision to ensure that the risk of whisker for- free solders. The elemental analysis capability of XRF is mation is reduced.The precision of the standardless mea- suited for analyzing solid samples of wave solder alloys. surement is dependent on the quality of the equipment, Similarly, elemental analysis of through-hole and SMT consistency of the measurement parameters and the solder joints can be achieved. This is useful when inves- material being analyzed. For years, environmental agen- tigating the possibility of excessive gold in a solder joint cies have used XRF to detect Pb in soil down to the parts (which could result in gold embrittlement). per million (ppm) level. Using XRF to detect ppm levels of Pb in electronic materials such as solder, ceramics and Nondestructive and Nondamaging plastic encapsulates is best performed with the help of a One advantage XRF has over other elemental analy- certified calibration standard. sis techniques is that it is nondestructive. The relatively If excessive levels of chromium are detected by XRF, low energy x-rays do not damage electronics compo- additional analysis will confirm whether the chromium nents, circuit boards or assemblies, and components is in the hexavalent form banned by the directives. XRF can be used immediately after testing. If static-sensitive cannot account for the form in which the substance is devices are to be tested using XRF, implement special present, and the directives set limits specifically for the grounding precautions to ensure ESD protection. hexavalent form of chromium (Cr6+). Distinguishing Unlike other elemental analysis techniques, no addi- the banned substance polybrominated biphenyl (PBB) tional sample preparation is required to examine test sam- from polybrominated diphenyl ether (PBDE) presents ples. For example, EDS often requires applying a conduc- the same challenge. tive coating to the samples as part of SEM preparation. As with any other analysis technique, knowledge of Auger electron spectroscopy (AES) and atomic absorp- the sample can increase the precision of the result. XRF tion (AA), two highly precise elemental analysis tech- operators are at a severe disadvantage when attempting niques, require dissolution of the samples into a solvent. to gather quantitative data from an unknown system XRF also has a speed advantage over other tech- with multiple layers. XRF is known as a surface techniques. Analysis can be completed in 30 sec., making nique, but the XRF incident x-rays can penetrate XRF practical for the time-sensitive manufacturing through multiple layers. This can lead to imprecise, environment. The short analysis time reduces the over- exaggerated results. The EMPF laboratory has wit- all cost of analysis, particularly if samples are sent to an nessed cases where Pb in the terminal metallization outside laboratory. Cost for analysis of a sample using underneath the surface finish exhibited a false positive XRF is typically less than half the cost of analysis using Pb reading in what was a pure Sn finish. XRF is also SEM and EDS. ineffective at measuring lighter weight elements, so Most XRF analyzers create precise quantitative ele- organic contamination analysis is not possible. mental measurements without the use of expensive stan- The recent European directives have led to a surge in dards. For plating thickness measurement and general interest in XRF. XRF is a quick, efficient tool for ensur- elemental composition analysis, standardless measure- ing compliance to the legislation. However, for precise ments are sufficient. For instance, DoD manufacturers levels of Pb, Hg, Cr6+ and other banned substances, the requiring 3% Pb in Sn-based surface finishes are typical- use of standards and additional analysis techniques may ly supplied components with Pb content of 10, 15, 37 or be necessary. ■

circuitsassembly.com Circuits Assembly FEBRUARY 2006 85 Wave Soldering Pb-Free Defects and Mitigation Common problems of Pb-free soldering, and how to solve them.

b-free wave soldering has its own list of common Solder wicking. Solder flows up the lead away from soldering defects. Even the most robust process the joint area, leaving insufficient solder to form a prop- P may, from time to time, experience defects. Fol- er connection. lowing is a list of common problems and descriptions, Component damage. Some components (e.g., MELFs) and some recommendations for their mitigation. that are left too long in molten solder wave may crack. Remember: Successful wave or selective soldering In other cases, their adhesive cannot withstand the tem- means creating a good solder joint between two surfaces perature and the components may drop into the solder. or objects, with both surfaces demonstrating good wetta- Solder contamination. Some metals will dissolve into bility (also known as solderability). The connection must Pb-free solder. Temperature, flow speed of the solder be designed so that solder will remain liquid during the and alloy composition will define how fast this will soldering process and not cool occur. Continuous monitoring of below its melting point during joint the solder composition is there- formation. This is called thermal fore required. solderability. Only when the Sans a sufficient If the solder pot’s construction demands of surface solderability protective layer, materials do not have a sufficiently and thermal solderability are met protective layer, the iron in the can joints be created for which sol- iron from the solder base material (stainless steel) will der is able to fill completely the dissolve into the solder and form

holes in a through-hole or mixed- pot will dissolve FeSn2 dendrites. The melting point technology board,thus reducing the of these crystals is 510°C; thus they potential for defects. into the solder. will remain solid in the solder. Remember also that all parts These crystals usually collect in the directly adjacent to the liquid solder in wave soldering corners of the solder pot, where there is less solder flow. will rise in temperature and expand due to the heat However, if they are pumped up with the solder, they introduced into the joint by the liquid solder. The may end up in a solder joint, causing bridging. degree of thermal expansion is not the same for all materials, but overall it is higher in Pb-free soldering. Recommendations For epoxy-glass board materials, this thermal expansion A number of defects are related to board material has a variable value, depending on temperature. This quality. The solderability of boards relies on good stor- expansion will become extreme in the z axis. age conditions, well-controlled logistics and a qualified The combination of longer contact times and high- board supplier. er solder temperature is dangerous, because it can lead With wave soldering, the solder temperature should to certain defects. be as low as possible. This will prevent overheating of Blow holes. These result from gases exiting the board components, damaging materials and, most important- material due to high temperatures. These gases escape ly, re-melting of solder paste (secondary reflow). Gerjan Diepstraten through the copper barrels into the solder, creating Lower solder temperatures neutralize the corrosive is a senior process large voids in the solder. effects of molten tin on ferrous machine parts – such as engineer with Solder excess. This is due to outgassing on top of the the solder pot and impellers – and will eliminate FeSn2 Vitronics Soltec BV board; the excess solder is clearly visible. dendrite formation. (vitronics-soltec.com); Copper leaching. Copper from the pad dissolves into In wave soldering as well as in reflow, many defects gdiepstraten@nl. the solder. Extremely long contact times will result in are caused by insufficient flux activity. A good flux that vitronics-soltec.com. complete dissolution of the copper if it is too thin. is able to withstand high temperatures can prevent His column appears Secondary reflow. Surface-mount components will bridging and improve through-hole penetration. Many monthly. re-melt if the process temperatures of the wave exceed designs of experiments have proven the importance of the melting point of the paste. The solder will wick away flux for these processes. and the component’s leads may release from the pad. Greater process control will reduce defect levels. Occasionally, a small connection between lead and pad UseofSPC and Pareto techniques to monitor process will remain, making detection of this defect even more robustness and to improve the design of the assembly difficult since there is still a current flow. Placing heat is key. Sufficient process control in the reflow process sinks on the leads of vulnerable components will pre- will prevent overheating and reduce the incidence of vent re-melting. other defects. ■

86 Circuits Assembly FEBRUARY 2006 circuitsassembly.com

Countdown to Pb-Free Implementing RoHS in the U.K. Discussions over exemptions continue, but RoHS will take effect July 1.

Ed.: For the full article, please see circuitsassembly.com/cms/content/ • Large-scale stationary industrial tools consisting of a view/2712/ combination of equipment, systems, products and/or components, each of which is designed, man- he Restriction on the Use of Hazardous Sub- ufactured and intended to be used only in fixed stances directive, adopted by the European industrial applications. T Union in 2003, bans the sale of new electrical • Spare parts for the repair of EEE placed on the market and electronic equipment in the EU by July 1, 2006, if before July 1, 2006. Following discussions in the Tech- products contain more than the permitted levels of nical Adaptation Committee, the EC and member lead, cadmium, mercury, hexavalent chromium, or states have broadened this exemption to include parts polybrominated biphenyl or that expand the capacity of and upgrade EEE placed polybrominated diphenyl ether on the market before that date, provided the EEE con- flame-retardants. The legislation cerned is not put on the market as a new product. LEAD-FREE WATCH applies across the EU; however, •The reuse of EEE placed on the EU market before 5 months each member state must enact its July 1, 2006. Countdown to July 1, 2006 own national version of the law. •Specific applications of lead, mercury, cadmium, The legal base of the RoHS direc- hexavalent chromium, PBB and PBDE as set out in tive is Article 95 of the EU Treaty, Schedule 2 of the Regulations. which means that the legislation introduced in each •The original exemptions outlined in the annex to member state will have the same impact and effect. RoHS were amended by two decisions published in In the U.K., the RoHS directive will be implemented October. Additional exemptions include ECA-BDE through The Restriction of the Use of Certain Hazardous in polymeric applications and Pb in PbBr bearing Substances in Electrical and Electronic Equipment Regula- tions 2005, introduced in Parliament last October. The Annex D regulations will be enforced by the National Weights and An example of a flow chart designed to clarify the compliance process and that Measurements Laboratory. This article reviews some key could help producers determine when analysis of components might be advisable. issues in development of this legislation, the U.K.’s approach on these issues and the efforts to harmonize Component / Material Take no further action legislation among the member states. Take no further action Yes to all 3 The RoHS directive applies to EEE falling into eight of questions the 10 broad product categories listed in Annex 1A of the No 1. From same supplier; 1 High risk of a WEEE directive. An important point to note is that what 2. Regularly checked over No Has it been Yes banned previous 3 years; and assessed in the substance being 3. Always RoHS last 12 months? present? falls within the scope of the WEEE directive (and, there- compatible? fore,the RoHS directive) is a matter of interpretation; only Yes No to any of 3 Analyse every batch questions acourt can give an authoritative ruling. In the absence of until confident risk is low Reassess

adefinitive legal ruling, member states must interpret the No

scope of provisions to implement the directive. Have previous Is it marked to Is this a high-risk Yes Yes supplier indicate component or declarations been compliance? material? The U.K. has promoted discussions among member accurate? states to develop generic criteria to help stakeholders No Request materials declaration and national enforcement authorities determine specif- certificate from Yes No Yes ically what products are covered with the aim of ensur- supplier

Yes to Analyse Steven Andrews ing a harmonized approach across the EU. The outcome Is this a new either Certificate part or from a random obtained? is head of the Eco- of these discussions is reflected in the European Com- new supplier? batches design and Product mission’s FAQ document2 and the DTI’s own guidance No No Analyse before 3 Is there any Policy Unit, Sustain- notes, published in November. (See the online version use (repeat Yes doubt over frequency based reliability of able Development of this article for further discussion of how to deter- on risk) declaration? NB Regularly check Directorate, U.K. mine whether products are within the scope of RoHS.) No accuracy of low cost screening against Department of Trade Take no more accurate further action technique and Industry Several Exemptions (dti.gov.uk); Several exemptions are listed in the annex of the FIGURE 2: This flow chart of the compliance process is steven.andrews@ RoHS directive, and additional exemptions were intended to help producers determine when analysis of com- dti.gsi.gov.uk. approved in October. 4 Exemptions include: ponents might be advisable.

88 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Countdown shells and bushes. The U.K. RoHS regulations will not contain more than the permitted level of any of the to Pb-Free soon be amended to reflect these changes. six restricted substances. In the U.K., producers are Other exemption requests are still under considera- required to keep records for up to four years after a par- tion by the EC and are likely to be put before member ticular EEE product is placed on the market. states for votes, again, in the near future. The EC has Materials declaration is an area where standardiza- published a fourth stakeholder consultation regarding tion will benefit producers and the enforcement several proposed amendments to the RoHS Directive authorities. The industry finalized the EIA-JGPSSI Joint annex.5 The consultation period ends Feb. 10. Industry Guide to Material Declarations in 2005. That guide provides the list of relevant substances that war- Maximum Concentration Values rant supply chain disclosure. IPC-1752, Materials Dec- ForRoHS regulations, a maximum concentration laration Management, was, when this article went to value (MCV) of up to 0.1% by weight in homogeneous press, expected to be released in early 2006. IPC-1752 is materials for lead, mercury, hexavalent chromium, PBB a uniform data format for supply chain material con- and PBDE and of up to 0.01% by weight in homogenous tent disclosure. materials for cadmium will be permitted in the manufac- Producer analysis. Producers of EEE to be placed on ture of new EEE. These values were established through the U.K. market may wish to undertake (or ask a third the adoption of a Commission Decision onAug.18,2005. party to undertake) their own analysis of the compo- “Homogeneous material” is nents or materials used in their material “of uniform composi- products (Figure 2).This action tion throughout,” meaning it may verify supplier declarations cannot be mechanically dis- The U.K. will accept or determine the presence of jointed into different materials. self-declaration as the any restricted substances in Examples include individual cases where no declaration is types of plastics, ceramics, glass, basis for compliance. available. It may also be under- metals, alloys, paper, board, taken if there are doubts over resins and coatings. The term the reliability of declarations. “mechanically disjointed” means that the materials can, Producers or third parties may employ any suitable in principle, be separated by mechanical actions such as analytical technique to establish that their products com- unscrewing, cutting, crushing, grinding and abrasive ply with the MCVs of the restricted substances. The crite- processes. riafor analysis will depend on the quantity of product put Using these interpretations, a plastic cover would be onto the market (less for small producers than for large a homogeneous material if it consisted exclusively of producers), the relationship with suppliers, the risk of a one type of plastic that was not coated with or had banned substance being present and the potential impact attached to it (or inside it) any other kinds of materials. of that substance on the environment. Producers must In this case, the MCV of RoHS would apply to the plas- ensure that they understand and take into account any tic. On the other hand, an electric cable consisting of limitations of the analytical technique they use. metal wires surrounded by nonmetallic insulation Enforcement. RoHS compliance in the U.K. will be materials is not homogeneous material because enforced in a variety of ways, including making test mechanical processes can separate the different materi- purchases; requesting compliance documentation, als. In this case, the maximum concentration values of inspecting processes and performing analytical tests; the RoHS regulations would apply to each of the sepa- and issuing compliance notices requiring certain rated materials individually. actions be taken. In Europe, the U.K. has been very active in attempt- No Prescribed Compliance ing to secure the adoption of a common approach. It is Producers must demonstrate compliance with the hoped that a network of member state enforcement regulations by providing the enforcement authority (on bodies will be established and that common guiding request) with relevant technical documentation of infor- principles will be agreed and adopted in advance of the mation. The U.K. intends to accept self-declaration as the July 1 deadline. basis of the compliance regime.The enforcement author- The RoHS directive has been a reality in Europe ity will carry out market surveillance to detect noncom- since January 2003, and regulations in most EU mem- pliant products and may conduct tests for this purpose. ber states are now final. Discussion on key issues, such There is no prescribed method to demonstrate com- as the exemptions, will continue for some time, but the pliance, and both materials declarations and component RoHS legislation will come into effect on July 1, both or material analysis are likely to play important roles. within the U.K. and across the EU. ■ Materials declarations. Producers of EEE should obtain assurances from their suppliers that any materi- Ed.: For a list of references and resources, please see the online version of als, components, assemblies or equipment provided do this article.

circuitsassembly.com Circuits Assembly FEBRUARY 2006 89 Process Doctor Know Your Sources When it comes to contaminants, what you do not know can hurt you.

Ed.: For the full article, please see circuits water could continue to redeposit assembly.com/cms/content/view/2711/ as the cleaner operated. We examined potential sources tisimportant to be aware of all of these harmful residues.Ion chro- potential sources for contami- matography analysis showed that I nation in an assembly process. the primary source came from the We must also understand whether fabrication process. Our evaluation cleaning equipment is doing its job FIGURE 1: Hazy, uncleaned flux residue of incoming bare boards found and if cleaning processes are in underneath a resistor. very high chloride levels. These control. A good qualification residues introduced during fabri- process and monitoring processes cation permitted board level para- will help ensure assembly of clean, sitic leakage, which caused failures. reliable products. We found several other potentially An electronics manufacturer harmful residue sources. Finger was experiencing field failures on cots and ESD gloves used by per- boards after switching to a new sonnel were high in chloride. Han- cleaning process. The previous FIGURE 2: Resistor area remedially dling circuit boards with materials process produced failures as well. cleaned at Foresite. high in residue content, especially The failures were occurring in the when wet, opens the door to trans- area of a low-standoff component. Samples sent to Fore- fer ionic species. Our consultant also examined the reflow site for localized cleanliness analysis included three good oven. Most zones were functioning properly, but the cool- working boards and three failing boards from each wash ing zone had a prolonged vapor accumulation of solder procedure, as well as five bare boards. All failing units flux residues.This accumulation can cause sporadic intro- showed very high chloride and weak organic acid flux duction onto boards as they pass through the chamber. residues in the area of the failing low standoff component. Other elements in this process such as the housings, PVC These results indicated poor and inconsistent cleaning gloves, water, stencils and incoming components were (Figure 1).Wealso looked at several reference areas on the found to be clean. finished assemblies, and the failing units showed margin- Our recommendations involved first taking the ally high chloride levels here as well. Obviously a serious cleaning equipment out of commission until full quali- cleanliness issue needed to be addressed. Boards were sent fication data could be obtained, all observed problems to Foresite for remedial cleaning,and we were able to erad- repaired and a system developed to monitor equipment icate residues that were the culprits in the field failures effectiveness and provide appropriate alarms when (Figure 2),pointing more conclusively to a weakness in zones were inoperative. Once the equipment could be this customer’s cleaning process. qualified, we suggested following the flux manufactur- To find the problem, Foresite dispatched one of its er’s guidelines for wash temperature, and to use a good process consultants to the location producing the fail- saponifier to effectively get underneath low standoff ing units. After examining the processes and equipment components and drive off ionic residues. Second, we Terry Munson is used to clean these assemblies, it was found that the recommended that the assembler to work with the fab- with Foresite Inc. equipment gave no alarms to warn if a zone was inop- ricator to obtain ionically clean bare boards. Finally, we (residues.com); erative. We found a number of issues that were critical recommended that the client begin using a localized tm_foresite@ to cleaning effectiveness, including low water levels, cleanliness monitoring protocol on its production floor residues.com. His clogged nozzles and inoperative cleaning zones. Water to track cleaning effectiveness around the sensitive low- column appears levels were low enough that the machine was unable to standoff components that were prone to residue entrap- monthly. pump water during the rinse cycle, and the operators ment. Thus, a cleaning weakness can be caught before a had no indication that this was occurring. Also, this reliability issue occurs (Table 1, online). customer did not follow the solder paste manufacturer’s This case shows that not having monitoring capabil- guidelines for wash temperature, and did not monitor ities and a qualified and controlled assembly and clean- water quality or use a saponifier. The lack of a rinse ing process can lead to major reliability problems. process contributed to the problem, as contaminated These problems may not be apparent immediately, but wash water was deposited on the cleaner curtains as happen slowly over time and are not discovered until boards passed through, and contaminants from this quality issues arise. ■

90 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Live and on-demand technical Webinars for electronics industry professionals

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To register, learn more or view the latest list of upcoming live, on-demand and technical training Webinars, visit www.pbrseminars.com now. Equipment Advances Juki’s Selective Soldering Systems The 300 and 400 series meet the range of needs for selective soldering of components following reflow.

uki 300 is a complete, economical solution for selective soldering of J conventional components. It is compatible with lead and Pb-free alloys, and is highly reliable. The system has a drop jet fluxer for smaller soldering areas, a spray fluxer for larger areas and apressurized tank that supplies flux consistently to the spray heads. Juki 300 provides a convection preheater for flux activation. Up to three different quickchange nozzles, ranging from 4 to 30 mm in diameter, are available. Special nozzles can be designed for custom

applications. An N2 management system is used to reduce consumption. The inert environment also limits dross buildup, widening the process window The Juki 400 has a three-stage batch or inline system for high-speed, auto- and reducing maintenance. mated selective soldering. The system comes equipped ready to begin production. In addition to a soldering unit with from a single-action system into a multiple-action sys- nitrogen inertion at the mini-wave, it includes: tem. The triple cycle permits the system to flux, preheat exchangeable mini-wave nozzle (one 6 mm nozzle and solder simultaneously. included), autofeeder solder roll device, machine and The system uses a patented Tenifer nitrate process to offline programming software, float sensor for main- protect from de-alloying caused by aggressive alloys. taining constant levels of solder in the pot and a Pb-free This is an actual process – not a coating that is embed- exchangeable solder pot with 25 kg capacity. ded into the steel. The same process is used in the Glock Juki 400 is a low- to mid-cost flexible machine for military and police handgun barrels. The systems fea- either batch or inline capabilities. The system offers the ture a patent-pending application that uses forced hot

functionality and features of the 300, plus a three-stage air N2 at the mini-wave to lower the temperature of the inline system for a high-speed, automated soldering solder and decrease the time of contact to help elimi- process. It can be customized to meet specific require- nate leaching and delaminating, improve flux activation ments. and reduce bridging. Juki 400 is Pb-free ready; it has multiple solder pots, Wiring systems and components are laid out in an permitting the use of leaded and Pb-free solder without efficient, visible and easy-to-read format. This com- hardware changes. This advancement provides signifi- bines with easy access to all maintenance areas, for ease cant savings. The system has multiple mini-wave noz- of service. Most options and accessories are field-retro- zles, for flexibility. Up to four are available; however, it fittable. ■ can be configured with three mini-waves in a panel, two mini-waves in a panel with different nozzles, with one mini-wave plus one full wave system or as a dip-soldering module. In addition to the mini-wave, a traditional full wave up to 400 mm can be installed and run during the same process. A key advantage of the full wave on the selective soldering machine is that users can use the same parameters to control the full wave as the mini- wave; e.g., multiple speeds, dwell, etc. This feature results in improved speed and throughput rates. Addi- tional speed/throughput improvements can be achieved through an XY Fluxer option, which changes the 400

92 Circuits Assembly FEBRUARY 2006 circuitsassembly.com wwwsmt-exhibition.com

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Exhibition & Conference Nuremberg 30 May – 1 June 2006

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Mesago Messe Frankfurt GmbH, Rotebuehlstr. 83-85, 70178 Stuttgart [email protected], phone +49 711 61946-74 Product SPOTLIGHT

Convection Reflow Oven X-100 compact reflow oven incorporates phase convection. Post-Reflow AOI Enables individual thermal profiling on a board-by-board basis Symbion S36 post-reflow AOI has a user- and thermal performance within the confines of Pb-free solder- friendly graphic wizard interface to reduce ing. Provides enhanced temperature uniformity and lower nitro- setup time and operator requirements. DPIX gen usage and power consumption. Uses SPC control with detection technology, based on specialized pyrometers. Features a self-cleaning capability. 3-D image acquisition and image processing ViTechnology brand, vitechnology.com techniques, reportedly ensures high accuracy detection and minimized false calls without compromising speed. Produces measurement and attribute data for SPC. Orbotech Ltd., orbotech.com

Inline Handling Station ENB-700 conveyorized station can sort PASS/FAIL products after AOI. It houses a DPM Identification single, removable magazine. PCBs that pass DataMan 7500 series handheld direct part mark readers read inspections are transferred to the next all printed and direct part mark (DPM) codes for manufacturers process through use of standard SMEMA. implementing part traceability. The ID readers combine IDMax PCBs that fail are transferred into a “50 code reading software with UltraLight illumination to read codes slot” removable magazine, and stored for regardless of marking method, part material, shape or surface future inspection and rework. Features texture. Includes 7500 corded and 7550 cordless models. include one-touch control panel, PCB Cognex Corp., cognex.com counter, selectable pitch (10 to 50 mm) and sliding magazine platform. Promation, pro-mation-inc.com

Mfg. Software Upgrade Visiprise Manufacturing 4.1 now includes: 1) integrated product dashboard to view work instructions, assembly components and data collection requirements through a Protective Tape single, configurable dashboard; 2) device Scapa 650 high-temperature masking tape is for low static pro- history record reports display complete tection of gold-plated finger tabs, assembly holes and compo- product history through a single view or nents during flux, preheat and soldering.Also for industrial mask- record; 3) time-based component traceabili- ing in cleanroom environments. Consists of a specially treated ty includes feeder staging for faster machine paper, single-coated with a silicone pressure sensitive adhe- changeover; 4) lightweight directory access sive. Reportedly delivers low ESD at unwind. After processing, protocol permits authentication over the removes from the surface without leaving residue. Internet; 5) enhanced data collection. Scapa Industrial, scapaindustrial.com Visiprise, visiprise.com

Portable Stencil Cleaner USC 400 ultrasonic cleaning system can be taken to the stencil printer to clean stencil apertures without resetting and calibrat- ing the printer. When offline, can be used with a bench-mounted or standalone stencil Handheld XRF Analzyer cleaner. Can be used with solder paste or Handheld x-ray fluorescence NITON analyzer has a helium SMD adhesives, is suitable for stainless and purging mechanism for direct analysis of “light elements.” Pro- plastic stencils. Cleans pick-and-place noz- vides immediate chemical analysis of alloys, electronic materials, zles, dispensing needles and probe test pins, coatings, plastics and more. XLt 898He can analyze the elements and can soften solder paste. Mg, Al, Si, and P in most alloy materials. Surface Mount Technology (SMT), Thermo Electron Corp., thermo.com [email protected]

94 Circuits Assembly FEBRUARY 2006 circuitsassembly.com Product SPOTLIGHT

PCB Depanelizer Low-Volume Selective K2000 motorized circular blade depanelizer separates prescored Soldering PCBs without dust or scrap. X-Y table permits improved board KISS 102 automated, programmable selec- handling. Has front and back blade guards, and an adjustable tive soldering system features Pb-free com- upper front blade guide. When using the X-Y table, the operator patible solder pots for low-volume assembly, places the PCB onto the table’s guide rails and brings the score- prototyping and rework, post-reflow offline line between the top and bottom blade guards. The motor driven assembly and applications such as odd-form lower blade pulls the PCB through to separate the panels.Two cut- devices. Standard and custom nozzles avail- ting speeds are available. Singulates panels up to 12.5". able. Benchtop model has optional carriage FKN Systek, fknsystek.com for standalone use. Has traveling mini-solder wave. Ascentech, ace-protech.com

Modular Cleanroom Wave Solder Fixtures Series 560 vertical flow modular hardwall Custom wave solder fixtures use customer-supplied Gerber and cleanrooms are prefabricated and easy-to- drill files for precise routing for component bottom-side pocket- assemble. Pre-engineered, freestanding ing and permit thicker, more stable fixtures. Stepped-down open- rooms require only a solid, level floor for sup- ings on the solder side prevent turbulence and component skip- port. Sections may be removed or reconfig- ping, provide a positive-locking clamp system. Accommodate ured for a process change, or for relocation densely populated boards with tall secondary side components, to another facility.A variety of sizes are avail- can solder through-hole components adjacent to SMT devices. able. Use a full HEPA filter ceiling bank and Can be supplied for boards up to 24" wide. HEPA-N-Seal double-gasket seal. Datum Dynamics USA, datumdynamics.com Clean Air Products, cleanairproducts.com

Dispense Valve Model 2200-245-125 Tip-Seal valve dispenses low- to high-viscosity flowable materi- High-Mix Chipshooter als. Also for high-speed stitching or repetitive MG-2 chipshooter is for high-speed, high-mix applications such on-off applications. Dispenses solvent-based, as automotive, memory boards and PC peripherals. Can be used moisture-curing and stringy materials such as alone, at speeds up to 40k cph, or with the MG-1 or MG-8 mul- silicones or polyurethanes. Opens and closes tifunctional machines. Features dual-gantry system carrying four its material passage at the tip of the nozzle to beams, each with six heads. Places components from 01005 to start/stop material flow. Prevents material CSP, BGA, PLCC and QFPs with 50-µm accuracy at 3 sigma for from hardening in the nozzle, oozing or drip- chips. Accepts 96 smart feeders; accommodates tape, stick and ping. Pneumatically actuated, has a carbide bulk feeders. tip, titanium-coated shaft, hardened seat and Assembléon, assembleon.com wear-resistant fluid seals. Sealant Equipment & Engineering, sealantequipment.com

PCB Prototyper Vibration Isolation Workstation ProtoMat S42 is an entry-level circuit 9600 Series Vibration Isolation Workstation is made of stainless board plotter for in-house rapid PCB proto- steel using cylindrical welded braces. Enclosed isolation module, typing. Compact system can mill and drill stainless steel valves and vented exhaust maintain Class 1 and 10 single- and double-sided board prototypes cleanroom standards. Available with electropolish or clear passi- in a single day. Has 42,000 rpm spindle vate finish. Features low natural frequencies and high isolation motor; fiducial recognition camera and vac- efficiencies. Has a dual-chamber compressed-air system for vibra- uum table are options. tion damping and a preset “zero deflection” level to compensate LPKF Laser & Electronics AG, lpkf.de for load changes. Available up to 36" deep and 60" wide. Kinetic Systems, kineticsystems.com

circuitsassembly.com Circuits Assembly FEBRUARY 2006 95 Technical Abstracts In Case You Missed It

Automated Optical Inspection received by EU member representatives and, if accept- “Getting Started with AOI – A Programmer’s View” ed, may constitute a cost-effective and reasonable Author: Ken Klima; [email protected]. approach for demonstrating RoHS compliance in the Abstract: Automated optical inspection provides a future. (SMTAI, September 2005) unique opportunity for seeing detailed views of electronics assembly. Each time an image is taken during an Solder Joint Reliability inspection, the processes of screen printers, placement “An Acceleration Model for SnAgCu Solder Joint Reliabili- machines and reflow ovens are captured and reviewed. ty Under Various Thermal Cycle Conditions” This technology draws upon existing skillsets of process Authors: N. Pan, G. A. Henshall, F. Billaut, S. Dai, M. engineers and introduces skillsets to line operators and J. Strum, R. Lewis, E. Benedetto and J. Rayner; francois. machine programmers. How these employees interact [email protected]. greatly affects the success of AOI. Identical AOI Abstract: Few quantitative models have been estab- machines have been introduced into the manufacturing lished for assessing the reliability of SAC solder joints process at two Rockwell manufacturing facilities. The under typical product service conditions. Specifically, top priority of AOI is to use the inspection results as validated models that take into account cyclic tempera- process feedback to aid in eliminating defects. AOI is ture range, maximum temperature and dwell time or also being used to measure placement machine accura- cyclic frequency are not readily available. In this study, cy, permitting closer calibration than ever before. This accelerated thermal cycle testing was performed using paper provides an AOI programmer’s view of the steps several thermal cycle profiles, in which the temperature taken to implement AOI into the manufacturing range (∆T), maximum temperature (Tmax), and dwell process. Topics include tasks to be identified when time (td) or cycle frequency (f) were systematically var- developing a plan, making best use of the training expe- ied. These various cycle profiles were used to perform rience, developing effective AOI programs, supporting solder joint reliability tests for three types of packages: programs in production and using data from the AOI 2533-CBGAs, 60-CSPs and 52-TSOPs. These Pb-free machine to reduce defects. This paper covers terminolo- packages were assembled to the PCB using SAC solder, gy unique to AOI and provides tips for efficient program producing entirely Pb-free joints. Data were analyzed development using real world examples. It also dissects using two-parameter Weibull statistics, and the charac- algorithms to examine how poor program parameters teristic life from each set of experiments determined. or a change in parts can lead to false calls. (SMTAI, Sep- These data were used to evaluate the constants in the tember 2005) well-known Norris-Landzberg acceleration model. The differences between the constants for SAC solder from RoHS Compliance those for eutectic Sn-Pb solder are discussed. (SMTAI, “Development of a ‘Systems Based’ Compliance Approach September 2005) to the European Union’s RoHS Directive” Author: Holly Evans; [email protected]. Wave Soldering Abstract: The RoHS Directive is silent as to what cor- Considerations for Lead-Free Wave Soldering porate actions will constitute legal compliance. Legal Author: Karl Seelig; [email protected]. compliance will not be easy given the lack of EU guid- Abstract: When converting to Pb-free wave soldering, ance on what products are covered and what actions several important business decisions need to be made. will be accepted by member states as evidence of com- The first decision pertains to the wave solder pot. Wave pliance. Furthermore, product producers cannot test solder pots designed specifically for Pb-free soldering CIRCUITS ASSEMBLY every product for RoHS compliance, given the cost and are resistant to tin corrosion, contain higher-grade stain- provides abstracts of destructive nature of testing. Recently, the European less steal components and typically contain lightweight papers from recent Information & Communications Technology Industry titanium hardware such as nuts and bolts designed to industry conferences Association (EICTA) proposed an “RoHS Compliance float rather than sink if dropped in the solder pot. and company white Process” to a number of EU government representa- SnAgCu alloys are aggressive toward the materials found papers. With the tives. This proposal sets forth a system-based approach in many older wave solder machines. If implementing a amount of information for demonstrating RoHS compliance and includes three SAC alloy for wave soldering, it is recommended that a increasing, our goal is key elements: 1) a producer self-declaration of confor- new wave solder machine, or at least a new solder pot, is to provide an added mance, 2) implementation of a documented system part of your expenditure. (aimsolder.com/techarticles/ opportunity for readers that demonstrates producer actions to restrict banned Considerations%20for%20Lead-Free%20Wave%20 to keep abreast of substances from the manufacturing process and 3) lim- Soldering.pdf) technology and busi- ited EU testing in cases where the system-based ness trends. approach appears insufficient. This proposal was well-

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