1. PERM 28 27-28 July 2016 SERDP ESTCP update and Tin whiskers users group: 8-81H Stephan Meschter PERM 29 Web Conference July 27-28, 2016 stephan.j.meschter@baesystems.com

2. PERM 28 27-28 July 2016 SERDP/ESTCP Lead-free Projects Update U.S. Department of Defense’s (DoDs) Strategic Environmental Research and Development Projects (SERDP) Environmental Security Technology Certification Program (ESTCP) https://www.serdp-estcp.org/Program-Areas/Weapons-Systems-and- Platforms/Lead-Free-Electronics 2

3. PERM 28 27-28 July 2016 SERDP WP2213  Complete: Nanoparticle enhanced coating formulation ○Conventional moisture cure urethane ○Dual cure UV-moisture cure acrylic-urethane Properties testing Coverage evaluation and whisker testing ○Traditional spray coat ○Sequential dip/cure/spray/cure/spray/cure layered coating  In-process Binghamton University: Layered coating coupon 4000 hour 85C/85RH inspection Celestica: Rework evaluation – planned completion 3Q2016 Celestica: Extended whisker testing – planned completion 1Q2017 ○6000 cycles total of simulated power cycling +50 to +85C thermal cycling BAE Systems: Final report – planned completion 2Q2017 3

4. PERM 28 27-28 July 2016 ESTCP WP201573-T2  Project Title: Enabling Lead-Free Interconnects in DoD Weapon Systems Principle Investigator: Dr. Stephan Meschter Team: Dr. Peter Borgesen, Dr. Indranath Dutta, Dr. Michael Osterman  OBJECTIVE: Transfer the SERDP lead-free technology to the DoD acquisition community program managers and systems engineers. Focus will be knowledge transfer in the areas of lead-free solder microstructure and fatigue behavior, tin whisker growth and tin whisker mitigation. Through development of a better informed acquisition community, the aim is to motivate appropriate lead-free materials control requirement flow down in systems management plans to lower implementation and sustainment risks associated with lead- free assembly adoption.  TECHNOLOGY DESCRIPTION: Three knowledge transfer methods will be used (1) webinars, (2) transfer of the tin whisker risk calculator to the University of Maryland Center for Advanced Life Cycle Engineering (CALCE), and (3) providing proposed updates to industry standards being developed and maintained by the IPC Lead(Pb)-free Electronics Risk Management Council (IPC-PERM).  EXPECTED BENEFIT: The transfer to the DoD industrial base is expected to be rapid and robust through IPC-PERM council and the CALCE membership ranks. The team will reach out to the DoD personnel participating in the IPC-PERM before severe travel and budget restrictions were encountered. We also have the opportunity to work directly with interested program managers and systems engineers to capitalize on the lead-free research findings in order to benefit the product lines for the Warfighter. 4

5. PERM 28 27-28 July 2016 ESTCP WP201573-T2  Knowledge transfer Webinars for the DoD acquisition community ○Overview ○Solder ○Tin Whiskers IPC-PERM Document Updates from WP1751 testing ○GEIA-HB-0005-2 ○GEIA-STD-0005-3 Update to CALCE Tin whisker risk calculator from WP1752 testing and modeling 5

6. PERM 28 27-28 July 2016 Help welcome  The product will be better with more inputs  Let me know if you are interested in helping Webinars ○PM webinar ○Solder webinar ○Tin whisker webinar SAE GEIA Doc update CALCE risk tool 6

7. PERM 28 27-28 July 2016 ESTCP WEBINAR OUTLINES 7

8. PERM 28 27-28 July 2016 Enabling Lead-free in the DoD through Risk Mitigation An Overview for Program Management and Systems Engineering

9. PERM 28 27-28 July 2016 Lead-free electronics overview  Lead-free materials  Global supply chain  Lead-free impacts Lead-free solder microstructure versus heritage tin-lead Lead-free susceptible to brittle fractures Tin whiskers  Configuration control and sustainment  Lead-free control plans requirements flow down  Resources Electronics assembly is impossible without solder Electronic support Warfighter Brittle fracture Lead-free solder fracture Tin whiskers Tin-lead solder

10. PERM 28 27-28 July 2016 Mission success depends on reliable electronics Source: PDUSD-Approved-TDS_AS_Outline-04-20-2011.pdf Electronics assembly is impossible without solder Risks: Push a button and it doesn’t go! In storage, but its already armed! DoD situation: High Mishap Severity (MIL-STD-882) System Failures Unacceptable Biggest concern: Undocumented or unmitigated Lead-free materials used in the wrong place at the wrong time.

11. PERM 28 27-28 July 2016 Lead-free Impacts  Commercial Lead-free electronics directives impact Department of Defense (DoD) electronics in many ways Multiple new failure modes have been identified and there are others to be discovered There is a return of old tin whisker failure modes, previously resolved with the addition of lead to tin Unless changes are made to procurement, we could be qualifying lead-free electronics to historical tin- lead solder databases that are not applicable There are early indications of problems that will manifest themselves eventually  DoD program managers, systems engineers, item managers, on down to bench technicians must be aware of certain directive impacts  A clear understanding of how to avoid these serious risks will help DoD assure Electronics products reliability Continued system readiness Maximize support to the warfighter Team awareness is key Program Managers Must be aware of soldering issues, incompatibility, intermetallics, schedule and cost impacts for part reprocessing as a result of lead-free replacements Systems Engineers Must be aware of soldering issues, incompatibility, intermetallics, alloy mixing issues, intermetallics, and reliability issues that could result in potential field failures. They will define material control requirements flow down, environmental testing, and tin whisker mitigation to mitigate risks.

12. PERM 28 27-28 July 2016 Pb-Free Electronics – New Failure Modes Electromagnetic Relay Short Circuit Cracked Solder Joint Open Circuit Photo Source: NASA Space Shuttle Program “Tin Whiskers” –Electrically conductive shorts –Metal shards, contamination –Arc flash leaves metal vapor Environmental Effects –Fractures in high shock & vibration environments –Higher melting temps –Incompatibilities with SnPb Solder –Less-repairable assemblies Configuration control problems - Mixed Pb and Pb-free inventory - Unidentified components

13. PERM 28 27-28 July 2016 Three distinct Pb-free problems  Escalation of acquisition and sustainment cost due to the major global reduction in the availability of leaded electronics materials;  Risk of failure due to tin whiskers is exacerbated by increased use of pure tin (or majority tin) finishes on components and printed circuit boards; and  Development of a clear understanding of the system performance and reliability of new Pb-free material sets (e.g. Pb-free solder interconnects, board laminates, part finishes, board finishes, coatings) and the test protocols needed to validate their performance. Source: 2014 AIA Joint Government and Industry Executive Forum on Lead(Pb) –free Electronics

14. PERM 28 27-28 July 2016 It is a DoD issue because:  DoD is using lead-free Mitigations vary with suppliers perceived need of systems criticality COTs to meets cost objectives and rapid prototype delivery schedules  DoD has always flowed down reliability requirements But, they are based on 30 years of tin-lead electronics use Need added DoD lead-free risk management requirements flow down  Want a DoD supply chain change to ensure it is going to get the reliability it wants with the lead-free materials Ask for the right requirements Definition of mission/use environments much more important than ever Utilize lead-free COTs with mitigations where there are benefits ○Lots of DoD systems have 0-100 C operating ranges and benign vibration/shock ○Maybe use 5/10 year tech refresh - Programmatic risk management for 20 year life  Open item “Objective evidence for reliability” Industry consensus still lacking Lead-free materials need analysis beyond the heritage tin-lead  Sustainment DoD owns equipment longer than some companies exist Needs to know what materials are used where DoD needs to be a well informed customer

15. PERM 28 27-28 July 2016  Establish team knowledge Accurate review of reliability analysis and test Tin whisker mitigation validation Informed lead-free control plan review  Ensure materiel will function as required in intended operational environments Tin-lead is increasingly costly or not available Some applications can likely use Lead-free with analysis and mitigations Flow down Lead-free Control Plan Requirements Data Item: DI-MGMT- 81772  Leverage Resources SERDP Research IPC-PERM Industry Consortia Defense Acquisition University Training ○DAU CLL007 Lead-free Electronics Impact on DoD Programs Programs Lead-free Action Plan

16. PERM 28 27-28 July 2016 SOLDER AND WHISKER DETAILED WEBINARS 16

17. PERM 28 27-28 July 2016  Properties are determined by microstructure  Initial microstructure depends on design and process  Microstructure keeps changing with specific combination of storage and use conditions  This leads to surprises and greatly complicates test requirements/protocols and interpretation of results (‘best in test’ often not ‘best in service’) modeling  Overview outlines mechanistic understanding and practical recommendations – identifies sources for detailed info No-Pb Solder Reliability

18. PERM 28 27-28 July 2016  Whisker growth factors, plating and solder Materials, cleanliness and solder thickness  Failure modes Low voltage and high voltage circuits  Short circuit mitigations SAE GEIA-STD-0005-2 review with emphasis on conformal coating  Short circuit risk modeling  Overview outlines whisker growth observations, mitigation approaches, and risk modeling – identifies sources for detailed info Tin Whiskers

19. PERM 28 27-28 July 2016 PERM Tin whiskers users group: 8-81H Risk modeling 19

20. PERM 28 27-28 July 2016 Transfer of risk calculator to CALCE  Support transfer of whisker risk calculator to CALCE  Make available on CALCE web site  Leverage part geometry data from CALCE PWA 20

21. PERM 28 27-28 July 2016 Distributions  Need more data from “Close Encounters”  Feed through CALCE for non-attribution  To help other use it the database needs: Materials Environment Whisker growth duration …More detail the better 21

22. PERM 28 27-28 July 2016 SERDP WP1753 testing 85C/85%RH: Length reference distributions 22 The lognormal mean, µ, in microns is converted to millimeters by subtracting ln(1,000) which is 6.9078. The lognormal shape is dimensionless and requires no conversion. Lognormal probability plot of whisker length (microns) comparing 1,000 and 4,000 hours of 85C/85%RH. LocScaleLoc microns-LN(1000)mm 1000 hrs2.7220.3381-6.90776-4.18576 4000 hrs3.9360.2954-6.90776-2.97176

23. PERM 28 27-28 July 2016 Dunn 30.5 yr whisker data 23 Ref: CALCE Tin Whisker Symposium 2014. Additional data available from the webpage http://esmat.esa.int under Publications http://esmat.esa.int

24. PERM 28 27-28 July 2016 Whisker parameters: Some other length reference distributions 24 Tin source Thickness (microns) Substrate Environmental exposure Maximum observed whisker length (microns) Lognormal µ (ln mm) Lognormal σ Density (whiskers /mm 2 ) Plated Sn CALCE 5 to 9Copper C194 2.5 years room, 1,000 cycles -55 to 85°C, 2 months 60°C/85%RH 39-4.5710.9866 2,192 to 3,956 7 to 9 Nickel plating over Copper C194 greater than 200-4.3060.8106126 to 3,573 Plated Sn Dunn ESA 5 Copper plated brass (specimen 11) (Lognormal parameter calculation assumed 1.67% whisker length = 10 micron and the 99.8% whisker length was the max (or avg,) length Ref. McCormack SMTA ICSR Toronto 2009 ) 15.5 years: 3.5 years room temp. and humidity, 12 years in a desiccator with dry room air 1,000 maximum specimen 11 length -2.6510.9212 Not available 733, average of specimen 11 maximum lengths at various locations -2.7830.8592 30.4 years: continued desiccator with room dry air exposure to 30.4 years 1600, maximum specimen 11 length -2.45191.0152 1033, average of specimen 11 maximum lengths at various locations -2.63750.9277 Note: Lognormal µ (ln mm) = µ (ln microns) – ln(1000)

25. PERM 28 27-28 July 2016 Closing remarks  Sign up now  Develop and present case studies of interest  Collaborate and compare notes 25