Case Study on the Validation of SAC305 and Sncu-Based Solders in SMT, Wave and Hand Soldering at the Contract Assembler Level
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
'Pin in Paste' Reflow Process with Combination of Solder Preforms To
As originally published in the IPC Printed Circuit Expo, APEX & Designer Summit Proceedings. Investigation for Use of ‘Pin in Paste’ Reflow Process with Combination of Solder Preforms to Eliminate Wave Soldering Guhan Subbarayan, Scott Priore Assembly Sciences and Technology, Cisco Systems, Inc. San Jose, California [email protected] Paul Koep, Scott Lewin*, Rahul Raut Cookson Electronics - Assembly Materials South Plainfield, NJ; *Elgin, IL Sundar Sethuraman Jabil Circuits San Jose, California ABSTRACT The Pin in Paste (PiP) technology is the process of soldering Pin through hole (PTH) components using the Surface Mount Technology (SMT) reflow process. The use of PiP process offers several advantages compared to the traditional wave soldering process. One of the primary advantages is lowering of cost due to the elimination of the wave soldering process and its associated tooling cost and potential handling damage. Another advantage is that with the wave soldering process, it is extremely difficult to achieve adequate holefill on thermally challenging thick Printed Circuit Boards (PCBs). However, by using PiP process with combination of solder preforms, it is possible to achieve adequate holefill and reliable solder joints for soldering PTH components. The objective of this study is to investigate the use and limitations of machine-placed solid solder preforms during the top- side SMT reflow process for PTH components. An experiment was designed to investigate the following problems: 1) How much additional volume is provided by the combination -
1.5 Repair and Re-Balling Stencils for SMD Components
Repair and Re-balling stencils 1.5 for SMD components Application Manufacturing in the laser cut and laser Stencil post-processing welding process With the introduction of SMD-technology All laser cut stencils from LaserJob are subjected and the constant drive toward miniaturization LaserJob stencils are produced in temperature- to an automated post-cut brushing process. of components, new procedures and repair controlled production rooms with a fiber laser. The CNC-controlled brushing system removes all processes are constantly being developed in Our custom fiber laser platform produces a exposed burrs on the laser exit side. The brush order to provide reliable repair materials and significantly better beam quality then commonly head travels across the entire stencil surface in safe repair procedures. Despite the low failure used laser systems. The distinct lower cutting horizontal and vertical directions. rates of many of the new integrated circuits, opening (20 µm instead of the commonplace the high cost of these devices, and the subse- 40 µm), with equal depth of focus sharpness, Advantages of this process quent cost of the populated PCB require a allows for reduced heat input into the material. – no enlargement of pad openings reliable repair solution. The high precision of the moderately conical – lowest material removal < 2 µm It is very rare for a new product to achieve a first- apertures increases the process window in the – consistent thickness of stainless steel pass yield of 100 %. Increased component pick and place operation and allows for more material geometries and component leads, particularly efficient solder paste release. with area array components, create the need As a standard feature, the repair stencils are for tighter tolerances and accuracy from rework offered in sizes from 10 mm x 10 mm to systems and rework stencils. -
Soldering Guidelines for Land Grid Array Packages Application Note 61
Soldering Guidelines for Land Grid Array Packages Application Note 61 Summary The objective of this application note is to provide Peregrine Semiconductor customers with general guidelines for the soldering and assembly of land grid array (LGA) packages. Precise process development and designed experimentation are needed to optimize specific appli- cation/performance. Introduction LGAs are grid array packages with terminal pads on the bottom surface. These are leadless packages with electrical connections made via lands on the bottom side of the component to the surface of the connecting substrate (PCB, ceramic, LTCC, etc.). The LGA is typically made with organic laminate or PC board as substrate with nickel-gold (NiAu)-plated termina- tions. Other component termination plating or substrate might be used based on application. The LGA solder interconnect is formed solely by solder paste applied at board assembly because there are no spheres attached to the LGA. This results in a lower standoff height of approximately 0.06 mm to 0.10 mm, which is favored for portable product applications. The lower standoff height also allows more space above the package for heatsink solution or for thin form factor application. LGA eliminates the risk that customers receive packages with damaged or missing solder spheres due to shipping and handling. Reflow soldering of LGA assemblies provides mechanical, thermal and electrical connections between the component leads or terminations and the substrate surface mount land pattern. Solder paste may be applied to the surface mount lands by various methods, such as screen printing and stencil printing. Peregrine Semiconductor LGA packages are categorized as surface mount components (SMCs). -
Medalist Bead Probe Technology
Keysight Technologies Medalist Bead Probe Technology Technical Overview An Ingenious, Yet Simple Method for Dramatically Improving Test Access The Keysight Technologies, Inc. Medalist Bead Probe Technology is the industry’s first, fully researched, documented and proven technology for placing test targets directly on printed circuit board (PCB) signal traces. These beads then serve as highly reliable test points for use during in-circuit testing. This new technique dramatically improves in-circuit test access on high density and gigabit-speed boards, resulting in excellent fault coverage. And best of all, plac- ing bead probes on a PCB requires no changes to your existing SMT process. Today’s Test Challenge: Smaller, Faster As PCB’s get increasingly smaller, the ability to provide test points for “Over 1.5 million in-circuit test becomes more difficult. Designs with high-speed buses also data points lead limit where test targets can be placed us to believe that on board layouts. Workarounds for these issues can often be time solder-bead consuming and costly, and sometimes simply not possible. probing is not only feasible in a high Unprecedented Access No access? No problem. Keysight volume production Bead probes are easily placed on has the solution. Test engineers can parallel traces with no re-routing environment, but now get the access they need for superior test coverage, even on the can be successfully most densely populated boards. In Use your current fact, numerous bead probes can be SMT processes implemented placed on multiple traces. Sit back and let your Keysight ICT tester select You can get started immediately without any the optimal bead locations for probing. -
Recommendations for Assembly of Infineon to Packages
Additional Information, DS1, March 2008 Recommendations for Assembly of Infineon TO Packages Edition 2008-03 Published by Infineon Technologies AG 81726 München, Germany © 2008 Infineon Technologies AG All Rights Reserved. Legal Disclaimer The information given in this document shall in no event be regarded as a guarantee of conditions or characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights of any third party. Information For further information on technology, delivery terms and conditions and prices, please contact the nearest Infineon Technologies Office (www.infineon.com). Warnings Due to technical requirements, components may contain dangerous substances. For information on the types in question, please contact the nearest Infineon Technologies Office. Infineon Technologies components may be used in life-support devices or systems only with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered. Assembly & Interconnect Technology Table of Contents 1 Package Description and Thermal Performance . -
Fundamentals of Solder Paste Technology Fundamentalsfundamentals Ofof Soldersolder Pastepaste Technologytechnology
Fundamentals of Solder Paste Technology FundamentalsFundamentals ofof soldersolder pastepaste technologytechnology Solder pastes are key materials Background water and nitrogen that also interfere with in surface mount technology Almost all electronics equipment contains soldering. (SMT) for assembly of printed circuit boards (PCBs), which are So, effective soldering requires that metal printed circuit boards (PCBs). critically important for satisfactory functioning surfaces are clean of passivating surface chemical Introduction of lead-free has placed new demands of the equipment. PCBs have patterns of layers through the use of a technique called on materials and processes electrically conducting copper tracks to which fluxing, which involves the application of a in SMT, requiring materials electronic components are joined. The joints chemical cream to the metal surface. The flux and process engineers to between the tracks and the components are must have the right chemistry to destroy surface adopt to lead free whilst made by soldering the components to the copper passivation layers. Fluxes for soldering electronic ensuring process yields stay tracks, generally by using a material known as PCBs require several features: at the highest possible levels. Key is the solder paste, a solder paste. 1. To remove the passivation layers and make material of great complexity Solder pastes are made by mixing a metal the metal surfaces active and wettable by the involving engineering sciences, alloy powder (around 90% by weight) with a solder alloy. metallurgy, chemistry cream-like material made of organic chemicals 2. To protect cleaned surfaces with a layer of and physics. This article (around 10% by weight). The organic chemicals some substance, usually rosin, which prevents helps those working with cream is referred to as ‘flux’ and is generally contact with air prior to application of the solder pastes improve their understanding of this key a trade secret and/or covered by patents. -
Bead Probes in Practice
Bead Probes in Practice Kenneth P. Parker Agilent Technologies Loveland, CO kenneth_parker at Agilent dot com Copyright © 2005 IEEE. Reprinted from ITC International Test Conference, Paper 26.2. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Agilent Technologies' products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it. Bead Probes in Practice Kenneth P. Parker Agilent Technologies Loveland, CO kenneth_parker at agilent dot com Abstract Bead Probes, a technology for In-Circuit Test probing of high-speed and/or high-density printed circuit boards was introduced at the 2004 International Test Spring-loaded plunger shaft Conference [Park04]. Since then much experimentation has been done with Bead Probe technology, and a large, high-density board has been designed and produced that makes use of them. This paper discusses the learnings from these efforts. Fixture-base target, 1 A Short Review of Bead Probes circular flat-faced A Bead Probe is a very small hemi-ellipsoid (y-dimension not to scale) structure made of solder. This bead typically lies on top of a signal trace, aligned to its width and following the trace Error for 4 to 6 times its width. -
Guide to Solder Paste Printing Process
A Guide To Solder Paste Printing Process By Michael Keens Table of Contents Introduction 3 Considerations 3 .... 1. Squeegee Speed 4 .... 2. Squeegee Pressure 4 .... 3. Stencil Separation Speed 4 .... 4. Stencil Cleaning 5 .... 5. Stencil and Squeegee Condition 5 .... 6. PCB Support 5 .... 7. Print Stroke 6 .... 8. Solder Paste Type, Storage and Handling 6 .... 9. Solder paste inspection (2D/3D) 7 Conclusion 7 A GUIDE TO SOLDER PASTE PRINTING 2 Introduction One of the most important parts of the surface mount assembly process is the application of solder paste to the printed circuit board (PCB). The aim of this process is to accurately deposit the correct amount of solder paste onto each of the pads to be soldered. This is achieved by screen-printing the solder paste through a stencil or foil but also can be applied by jet printing. It is widely believed that this part of the process, if not controlled correctly, accounts for the majority of assembly defects. The most common method of applying solder paste to a PCB using a stencil printer is squeegee blade printing – see images below. The squeegees are the tools used to apply the necessary force required to move the solder paste across the stencil and on to the PCB. They are usually made from metal but can also be made from polyurethane. Considerations The key parameters of an effective solder paste printing process are as follows:- 1. Squeegee speed 2. Squeegee pressure 3. Stencil separation speed 4. Stencil cleaning 5. Stencil and squeegee condition 6. PCB support 7. Print stroke 8. -
SHEETMETAL FABRICATION TECHNICAL TIPS for SOLDERING Flux
SHEETMETAL FABRICATION TECHNICAL TIPS FOR SOLDERING Flux In metallurgy, a flux (derived from Latin fluxus meaning “flow”), is a chemical cleaning agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time. They are used in both metallurgy and metal joining. In high-temperature metal joining processes (welding, brazing and soldering), the primary purpose of flux is to prevent oxidation of the base and filler materials. Tin-lead solder (e.g.) attaches very well to copper, but poorly to the various oxides of copper, which form quickly at soldering temperatures. The role of a flux in joining processes is typically dual: 1. As cleaning agents, fluxes facilitate soldering by removing oxidation from the metals to be joined by dissolving the oxides on the metal surface, which facilitates wetting by molten solder. The flux also acts as an oxygen barrier by coating the hot surface, preventing further oxidation during the soldering process. 2. Additionally, flux allows solder to flow easily on the working piece rather than forming beads as it would otherwise. In some applications molten flux also serves as a heat transfer medium, facilitating heating of the joint by the soldering tool or molten solder. FLUX TYPES There are two types of fluxes used for soft soldering. These are organic (rosin based) fluxes or inorganic fluxes, usually based on halogenides and/or acids. Common fluxes are: ammonium chloride or rosin for soldering tin; hydrochloric acid and zinc chloride for soldering galvanized iron (and other zinc surfaces); and borax for brazing or braze-welding ferrous metals. -
SMTAI 2018 Accelerating the Solder Paste Selection Process
Originally published in the proceedings of SMTA International, 2018 ACCELERATING THE SOLDER PASTE EVALUATION PROCESS Chrys Shea Shea Engineering Services East Greenwich, RI, USA [email protected] ABSTRACT Solder paste can make or break the profitability of SMT mitigate defects, but if the solder paste is not a good match processes. Using the proper chemistry is critical to a to the process or board design, their opportunities for successful operation. Because solder pastes have so many improvement are severely limited. Upgrading to newer different characteristics that affect their assembly line formulations has been shown to instantly reduce paste performance, they can be cumbersome and costly to formulation-related defects.1 evaluate. As a result, many assemblers are using mature formulations that have since been improved upon, simply Why not change solder pastes? because they don’t have the resources to properly evaluate The costs of line time, test assemblies, and technical new, more process- or product-friendly materials. resources add up fast. There’s also the risk of overlooking a critical property of the paste and choosing the wrong one for This paper proposes a new solder paste evaluation regimen the job, especially because there are no accepted industry that helps engineers assess up to 25 solder paste properties test methods to determine paste performance on an actual on their assembly line in 5 hours or less. assembly line.2 KEY WORDS: solder paste, solder paste evaluation, solder The SMTA Test Kit project was developed specifically to paste qualification, SMTA test board, SMTA test vehicle, address paste-related cost concerns. -
Guide to Soldering Jigs and Pallets
Guide to Soldering Jigs and Pallets By Bob Willis Despite the advances in electronic manufacturing which drive companies to the use of reflow soldering, wave soldering will be with us for many years to come. There are still many through hole components which can not be converted to surface mount and many products which do not benefit from changing to SMT. Wave soldering is a simple process Process Guides Bob Willis for through hole parts and less demanding than alternative like intrusive pin in hole reflow techniques. The move to lead-free manufacture also has an impact on pallet and process The soldering pallet, carrier or jig has been used for many years. Initially, a carrier was needed with fixed width chain conveyors to allow different board widths to be soldered. These early carriers were made from stainless steel or titanium, and were adjustable to allow operators to load different width and different size boards. Some of these fixtures were specifically designed to protect the leading edge of the board and prevent solder flowing on to the topside of the board. The front deflectors also provided support for the board during pre-heat and wave contact to minimise warpage. Often the deflector is used to mask the edge of the board when it features a series of gold edge contacts. These are normally used for interconnection to sockets on other boards, typical examples are PC graphic cards or boards for telephone exchanges. Example of front supports Unfortunately many design engineers continue to produce layouts which do not allow the correct support for wave soldering hence the need for soldering pallets. -
Evaluation and Implementation of No-Clean Solder Paste for Surface Mount Technology
••• • -- THE MASSACHUSETTS TOXICS USE REDUCTION INSTITUTE EVALUATION AND IMPLEMENTATION OF NO-CLEAN SOLDER PASTE FOR SURFACE MOUNT TECHNOLOGY WITH A Focus ON SMALL CONTRACT MANUFACTURERS GRADUATE THESIS Technical Report No. 40 1997 University of Massachusetts Lowell Evaluation and Implementation of No-CleaQ Solder for Surface Mount Technology With a Focus on Small Contract Manufacturers Doug Sommer Prof. Sammy G. Shina Mechanical Engineering Dept. University of Massachusetts Lowell The 1996 - 1997 Toxics Use Reduction Research Fellows Program The Toxics Use Reduction Institute University of Massachusetts Lowell 1997 All rights to this report belong to the Toxics Use Reduction Institute. The TOXICS USE material may be duplicated with permission by contacting the Institute. • REDUCTION • • INSTITUTE • The Toxics Use Reduction Institute is a multi-disciplinary research, education, and policy center established by the Massachusetts Toxics Use Reduction Act of - - 1989. The Institute sponsors and conducts research, organizes education and training programs, and provides technical support to promote the reduction in the use of toxic chemicals or the generation of toxic chemical byproducts in industry and commerce. Further information can be obtained by writing the Toxics Use Reduction Institute, University of Massachusetts Lowell, One University Avenue, Lowell, Massachusetts 01854. °Toxics Use Reduction Institute, University of Massachusetts Lowell Toxics Use Reduction Institute Research Fellows Program In 1991, the Toxics Use Reduction Institute