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COTS Test & Screening

JEDEC standards rely on device level quali- fabrication processes, assembly processes Test & Screening fication and testing to ensure delivered 12 and package components such as mold product meets the needs of the OEM. While compounds may not be considered as TI Enhanced Product Family COTS Controversy: 10 Test-in or Build-in Quality? a good start, such practices are not in and of affecting the form, fit and function of COTS themselves adequate to ensure long-term devices and may not be disclosed by the IC In response to customer needs, TI EP package qualification compre- 8 reliability in harsh environments. 150 MHz manufacturer. Therefore, IC manufacturer Texas Instruments has released the hends performance at extended temper- Even when the manu- quality and reliability data, if available, only Enhanced Plastic (EP) product family to atures with package element concerns facturer performs additional qualification 6 reflects a one-time snapshot of the existing 200 MHz facilitate, not replace, OEM qualification such as transition temperature and Beyond Quality – Assuring the and screening for operation at extended process baseline. It is an aggregate estimate of COTS devices through baseline con- thermal expansion coefficients taken into temperatures, it only provides a means to 4 of product performance within published trol and enhanced qualification pedigree. account. Electrical testing is warranted to

facilitate—not replace—OEM qualification Product Life (years) data sheet limits based upon history. Enhanced Plastic (EP) devices are meet the data sheet over the specified 2 Reliability of Plastic of COTS devices. Instead, defense system TI catalog products comprehending temperature range. Device characteriza- must examine the IC manufacturer’s COTS Standard Qualification and devices from multiple families including tion and statistical process controls are fabrication, assembly and qualification pro- 0 Screening Digital Signal Processors (DSP), Analog used to ensure performance over the cedures for integrated circuits to ensure reli- 95 100 105 110 115 120 125 130 135 Testing and screening semiconductor Encapsulated Integrated Circuits and Mixed-Signal, Digital Logic, ASIC, specified temperature range. Assembly, able operation over extended temperatures. products is performed in accordance with Junction Temperature ( deg C) Microcontrollers and Programmable test and qualification changes require the manufacturer’s data sheet for that Logic. Enhanced Plastic (EP) devices approval of the TI Technical Review Uprating and upscreening commercial components to extended temperatures are dangerous IC Obstacles Figure 2 device. Components are processed per “best Military and commercial avionics commercial practices” to the manufacturer’s offer several advantages over standard Board (TRB). practices that can adversely affect reliability and maintainability. Instead, look closely at the Electromigration: Life versus Junction Temperature. Maintaining the proper junction COTS products: For EP devices, TI will provide OEMs currently purchase 0.5% to 1.0% of temperature prolongs device life; reducing speed is beneficial to both. internal baseline flow. Processing and IC manufacturer’s fabrication, assembly and qualification process, policies and procedures. the total number of commercial integrated screening is typically documented in the change notification via the TI electronic circuits sold. With so many commercial manufacturer’s Quality Manual. Almost all • Stand-alone data sheets parts change notification (PCN) system if a change has the potential to affect form, applications driving OEM IC designs, as and monitors based upon generic industry relative quality and reliability of semicon- semiconductor manufacturers are certified • A controlled baseline—one S. Richard Biddle, Quality and Reliability Manager fit, function or reliability. In other words, much as 30 or 40 percent of COTS devices standards. Existing industry standards for ductor devices is quite limited. Since these to ISO9001. assembly/test site and one Texas Instruments, Military and Automotive Semiconductor Products Division changes to the baseline will be communi- destined for military use require uprating or plastic encapsulated microcircuit qualifica- monitors are performed on a periodic basis To ensure a device exhibits the best wafer fabrication site upscreening, depending on the OEM and tion and reliability monitors are based on random samples of devices, they cannot quality and reliability possible when using cated prior to implementation. Distributors or more than forty years the the application. For the purposes of this upon historical data, experiments and field be considered acceptance tests on any spe- that over an extend temperature • Enhanced product change notifi- will be independently notified to facilitate Department of Defense was the discussion, uprating is defined as use experience with the use of these devices in cific group of components. range or in harsh environments, additional cation (PCN) via electronic dis- notification of their customers. Fleader in publishing guidance for beyond the environment and application commercial and industrial applications. To further compound the problem, evaluation is needed: tribution In the event a proposed change component reliability and maintainabili- for which the part was designed. The applicability of these standards in device and process changes that do not Reliability and electromigration • • Die revisions does affect form, fit, function or reliability, Def/Aerospace • (Defense/Aerospace) ty. But as a part of Defense Acquisition Upscreening, on the other hand, is defined determining the suitability for use and affect commercial applications could checks at maximum recommended TI will take steps to minimize the impact Reform, the responsibility has now shifted as performing additional testing and/or lot safety performance in military and aero- impact the performance or suitability of operating conditions in the target • Assembly process changes on the customer. This may include contin- Automotive to the defense original equipment manu- acceptance to use product beyond data space applications has not been established. devices for military or other high-reliability package • changes such as mold uing production of the established base- • (Automotive) facturers (OEMs) where most programs sheet conditions. Other applications, such The value of process monitors in assessing environments. Changes to die , wafer Electrical characterization over tem- • compound and lead finish line after commercial production has Government are governed by performance-based spec- as ground-based systems, perature changed, establishing a wafer bank of the COTS • (Commercial ifications. Military and aerospace OEMs are more benign and COTS components • Confirmation of package perform- • Electrical performance current die revision and/or offering a life- Comm’l Avionics Avionics) 12 using commercial off-the-shelf (COTS) may be suitable for use without additional ance over extended temperatures (for time buy on the configuration in question. 3rdParty • location Design Upscreen components must now establish their own qualification or screening. example, some mold compounds are TI’s new products will offer an alter- Homeland Security Change standards for qualification and reliability. Uprating and upscreening are prob- 10 not suitable for extended temperature) • Extended temperature up to and native to upscreening for customers who Commercial semiconductor products lematic at best. Very few, if any, manufac- Health/Safety including -55°C to +125°C believe that a plastic packaged part is System-Level are not designed for military and aerospace turers will support this effort, and few 8 The term “Qualification Pedigree” is Qual Qualification pedigree to assure suitable for their particular application. Cell Phones applications. Instead, they’re designed for upscreening test facilities have the ability to used in the aerospace industry to define the • reliable operation over specified Although the EP products receive addi- use in a wide range of applications and test complex parts. The actual process of 6 qualification and characterization per- environments that are often at odds with upscreening has the potential to degrade formed by a manufacturer. Reliability mon- temperature range tional testing and process verification over and above their commercial coun- • (Electronic Toys) defense applications (Figure 1). With mili- component reliability. For example, there is itors are usually performed on a regular Assurance from TI that the Electronic Toys 4 • terparts, they may still not be suitable for Commercial Industrial Extended- Extended-Temp Extended-Temp Mil-Temp Mil-Qualified tary and aerospace platforms, some appli- the possibility of yield loss and damage due basis and include EFR (extrinsic failure rate) device will perform to data sheet ° ° Temp * Qualification * Custom * Compliance QML all environments. For those applications

0 to 70 C -40 to 85 C Product Life (years) cations are very benign while other appli- to electrical overstress and electrostatic dis- and IFR (intrinsic failure rate) life test, tem- electrical specifications in envi- * “Robust” * Controlled Electricals * Hermetic * Hermetic 2 that require a ceramic/hermetic pack- Qualification Baseline * Special * Mil-Temp * QCI Conformance cations require careful selection of the charge. Mechanical damage can degrade perature cycle and Biased Humidity or ronments that require extended * Change * Minimize Processing Performance * Mil-Temp proper device type to ensure system relia- moisture performance, and burn-in can Highly Accelerated Stress Testing (HAST). aged , TI has an expan- Notification Obsolescence * "Ruggedized" temperatures sive product line to meet their needs. * Timely/Accurate Qual bility. Each environment has very different cause lead finish degradation. 0 Test methods should be based upon accept- Change * Custom Part # requirements that must be addressed to As part of uprating and upscreening, 95 100 105 110 115 120 125 130 135 ed JEDEC and EIA standards. In the event a • Standard Nickel-Palladium- More information on EP products is avail- Notification * Stand Alone Spec determine what type of integrated circuit OEMs typically perform some type of qual- monitor discloses a device quality or relia- or Tin-Lead lead finish able on the Texas Instruments website at can be used in that environment. ification testing at the device and Figure 3 bility issue, the manufacturer decides what http://www.ti.com/sc/ep. Figure 1 Specifications such as ISO9000 and system level to ensure safe and reliable oper- TQFP Packaged Product Gold Wire Bond Life versus Junction Temperature. As Tj corrective action is required and whether to Multiple factors cloud COTS components selection. Unfortunately, defense and aerospace AS9000 focus on the quality systems used ation in their specific application. increases, the bond degrades and device reliability decreases exponentially. issue customer notification. applications are out of the mainstream markets targeted by most IC manufacturers. to manufacture integrated circuits. Other Integrated circuit (IC) suppliers, on the This product evaluation and qualifica- specifications such as AEC Q100 and other hand, perform qualification testing tion augments the product qualification and

Reprinted from COTS Journal Reprinted from COTS Journal Test & Screening Test & Screening End-of-LifeAnnual Directory DMSMS ® reliability monitors already inherent in a Control Point Test Sample Point Sample size/Frequency Control Method Description Condition Sample Size Referenced Method device operation) do not address humidity- manufacturer’s process. These standard induced failure mechanisms or temperature Metal Visual Post etch Each lot Lot accept qualification and reliability monitors Bias Life Test 125°C/1000 hour or 116/0 JESD22-A108 * cycling-induced failure mechanisms, which should include: Thickness Post deposition Each run SPC equivalent are found in non-benign environments. Extended temperature die reliability SEM step coverage Post sinter 1 wafer/deposition system Monitor These are addressed by the HAST or • Biased Humiduty or HAST 85°C/85%/1000 hours 77/0 JESD22-A101 * Package and/or prod family/week 85C/85% RH, and temperature • or JESD22-A110 • Overall qualification and reliability 130°C/85%/96 hours cycling tests. For moisture sensitive (per policies and procedures Field oxide Phosphorus level Post metal etch or post 1 wafer/week Monitor JESD A112A) plastic surface mount devices, emitter diffusion • Wafer level reliability Autoclave 121°C @ 2 atmospheres 77/0 JESD22-A102 * preconditioning per JESD A113A is typically absolute for 96 hours • Die level reliability C-V test Finished wafer Each lot Monitor performed before the moisture and tempera- Package level reliability ture cycling tests. Therefore, life test data • Interlevel Integrity Post via etch 1 wafer/reactor/week or 1 Monitor Temperature Cycle -65°C to +150°C non- 77/0 JESD22-A104 * Oxide (ILO) wafer/ILO structure/week biased for 1000 cycles must be supplemented with other environ- Die Level Design Reliability at mental test data in determining how a plastic Extended Temperatures Thickness Post deposition 1 pilot/reactor/run SPC Solder Heat 260°C for 10 seconds 22/0 JESD22-A106 device will function in a given environment. IC manufacturers design devices in Visual Post etch Each lot Lot accept Actual reliability in field conditions is also Resistance to Solvents Ink symbol only 12/0 JESD22-A107 accordance with a formal set of design Wt % phosphorus Post deposition 3 pilots/reactor/week Monitor affected by board assembly techniques and rules. These design rules are computer (doped ILO/MLO) Solderability Condition A (steam age for 22/0 ANSI/J-STD-002-92 conditions encountered during extended verified at numerous points during die 8 hours) dormant storage. design, layout and photomask genera- Gate oxide C-V test Post oxidation 1 pilot/furnace/week Monitor Plus: Flammability Method A/Method B 5/0 UL-1964 Plus: tion. A design model is developed for a Glassivation Visual Post etch Each lot Lot accept Package Level Reliability Monitors specific technology node with a device Package related monitors are typically Thickness Post deposition Each run SPC Bond Strength 76/0 ASTM F-459 Display and Imaging reliability model driven by predeter- performed by each assembly facility as dictat- Post deposition Each run Monitor Advances Take Warfighter mined reliability goals. These goals are Die Shear 5/0 MIL-STD-883 Method 2019 ed by the complexity of the technology and typically set to meet the expectations of Integrity Post etch 1 wafer/reactor/week or Monitor major end customer requirements. End point Vision to New Level the commercial end customers. This 1wafer/deposition High Temp Storage 150°C/1000 hours 45/0 JESD22-A103-A * electrical testing is usually performed to the model defines a specific set of maximum type/week datasheet at 25°C. Table 2 is a typical new Moisture Sensitivity Surface Mount Only 12/0 J-STD-020-A design conditions required to meet the package qualification performed to JEDEC Exclusive Interview with reliability goals. Table 1 *Precondition performed. Table 2 * Precondition performed. standards. Greg Saunders, A careful evaluation of the technol- Typical Wafer Level Reliability Monitor Program. A wafer level reliability monitor program put Typical New Package Qualification. qualifications are driv- After qualification, periodic monitors are Defense Standardization ogy and the device in question is required to ensure the assembly process is in place by the manufacturer is crucial to ensuring long-term silicon reliability and reduction en by industry standards and commercial customer requirements. Program Office, OSD: required to ascertain if a candidate of lot-to-lot variations. under control. Typically Biased Humidity (or Program Office, OSD: device will be reliable over extended qualification would differ from the release and gate/storage dielectrics HAST), Autoclave (or unbiased HAST), temperatures. Arbitrary derating of thermomechanical stress of the die, high when evaluating bond life. Candidate of a qualified die into an existing package. parameters. The specifics vary depending Temperature Cycling and Bake tests are per- Can COTS Reliability such a device could result in extreme temperature performance and moisture devices must be evaluated for Au/Al bond After initial qualification, various on process technology, such as bipolar or formed as monitors. Monitor sample sizes Be Tested In? degradation of operating life. Figure 2 performance. Since a single encapsulant intermetallic life based upon the die junc- quality and reliability monitors are per- MOS. Table 1 is a typical wafer level relia- are derived based upon total volume of pro- shows the operating life of a high com- cannot meet all requirements, designers tion temperature at maximum recom- formed. In the wafer fabrication facilities, bility monitor program for a TI wafer fab. duction and the maturity of the package fam- plexity device versus junction tempera- must consider the trade-offs. In some mended operating conditions. Failure to wafer level reliability monitors are per- ily. Sample sizes and actual testing performed ture, both at the specified operating cases, the designer will select a mold com- consider these factors can have a drastic formed to ensure that the wafer fab Die Level Reliability Monitors are subject to change. speed of 200 MHz and a reduced operat- pound for optimal performance and con- effect on product life. Figure 3 depicts processes are in control and producing die Periodic extrinsic failure rate and ing speed of 150 MHz. In some cases, sider only the commercial or industrial intermetallic related product life of gold to the wafer fabrication baseline. In the intrinsic failure rate life test monitors different recommended operating condi- temperature ranges. wire bonds in a 144-pin thin-quad-flat- assembly sites, package-related testing is should be performed for each technology tions are required at maximum tempera- Encapsulants consist of multiple com- pack (TQFP) versus junction temperature. performed to ensure that the assembly from each wafer fab. This typically con- TI ture. In other cases, a thermally ponents including resins, fillers, flame- process is in control and producing reli- sists of steady state life test for 1,000 hours Military and Automotive Products Division enhanced package is used for extended retardants and mold release agents. Of par- Standard Qualification and able devices. Periodic extrinsic failure rate at 125°C or equivalent. End point electri- Sherman, Texas. temperatures where a standard package ticular interest with respect to device relia- Reliability Monitors (EFR) and intrinsic failure rate (IFR) life cal testing is performed to the data sheet (800) 477-8924. will suffice for the commercial part. bility, are the flame-retardants. Bromated Qualification and reliability monitor- test monitors are performed. Monitors for conditions but typically only at 25°C. [www.ti.com]. will release bromine when heated. ing is usually performed at several levels. leading edge are more exten- Extensive testing is performed for a new Package Materials Design Bromine has the effect of accelerating In general, any new process or device sive than those performed for mature tech- technology. For periodic monitors of Considerations intermetallic formation between the gold technology is extensively qualified as a nologies. high-volume products, sample sizes range With plastic encapsulated integrated bond wires and the aluminum die bond stand-alone entity. Variations of existing upward to thousands of devices each quar- circuits, a critical consideration when pads (Kirkendall voiding or “purple processes or technologies receive a less Wafer Level Reliability Monitors ter per technology—inclusive of all wafer contemplating extended temperature plague”). extensive qualification. For example, the Most wafer fabrication facilities have fabs. For high-complexity devices, the operation is the physical properties of the When a device is in use the actual tem- release of a new family of digital signal established controlled specifications to sample sizes may range upward of several package itself. Multiple factors dictate perature of the mold compound is higher processors using a new wafer fabrication define wafer level reliability controls pro- hundred devices. the type of encapsulant used. These than ambient due to internal heating of the process would receive a different level of cedures and testing. In general, these Conditions found during life test include the flow properties during the die. Therefore the junction temperature of qualification than an existing product die procedures address metallization, protec- (that is, constant high temperature, low or mold process, cure characteristics, the device must be taken into consideration revision. A new package technology tive overcoat, multilevel/interlevel no ambient humidity, and continuous

Reprinted from COTS Journal