1. The Impact of Lead-free Soldering Processes on Defense Industry Electronic Assembly Practices Dave Hillman Rockwell Collins SMTA Huntsville Chapter 2011

2. The goal of Today’s Presentation/Discussion: Educate – Entertain - Engage!

3. Impact of Lead-free Soldering Processes on Defense Industry Electronic Assembly Practices Agenda: Background Specifications Lead-free Topics of Interest - in no particular order!

4. Graph Source: ELECTRONICS INDUSTRIES MARKET DATA UPDATE, Spring 2010 Whenever there is a challenge, there is an opportunity…………..

5. The Predominate Component Surface Finish Is…… Graph Courtesy of CALCE Consortium, 2009ish

6. Operational Service Life (Years) < 1% 29% 8% 62% Medical Equipment Cars Satellites Missiles Aircraft Spacecraft Industrial Products Major Home Appliances Cell Phones Desktop PCs Network Servers Harshness of Service Environment (Temperature, Vibration, Shock, Humidity) Consequence of Failure High Low 1 5 33020 10 Lead-Free Transition = Increasing Difficulty Military and Aerospace sectors have little influence on the global transition to Lead- Free (<1% Market Share)

7. Influence of Lead-free Soldering on the Defense Industry Products Military/Aerospace Electronic Products Characterization: Life Critical & Flight Critical Applications Extremely Stable Qualified Material Lists Significant Use Life ~ 20-30 Years Not Uncommon Manufacturing Mode: High Mix/Low Volume Design Cycle Mode: Deliberate and Long ~ 12 Months Customer Certification * Nothing is set in stone – and there is no guarantee that “legacy” products will have infinite exemption or exclusion status Graphic source: M. Kelly, SMTAI 2007, “Case Study: Qualification of a Lead-free Card Assembly &^ Test Process of a Server Complexity PCBA

8. Impact of Lead-free Soldering Processes on Defense Industry Electronic Assembly Practices

9. Agenda: Background Specifications Lead-free Topics of Interest (in no particular order!

10. LEAP WG Actionable Deliverables GEIA-STD-0005-1, Performance Standard for Aerospace and High Performance Electronic Systems Containing Lead- free Solder Used by aerospace electronic system “customers” to communicate requirements to aerospace electronic system “suppliers” GEIA-STD-0005-2, Standard for Mitigating the Effects of Tin Whiskers in Aerospace In High Performance Electronic Systems GEIA-STD-0005-3, Performance Testing for Aerospace and High Performance Electronic Interconnects Containing Lead-Free Solder and Finishes Used by aerospace electronic system “suppliers” to develop reliability test methods and interpret results for input to analyses GEIA-HB-0005-1, Program Management / Systems Engineering Guidelines For Managing The Transition To Lead-Free Electronics Used by program managers to address all issues related to lead-free electronics, e.g., logistics, warranty, design, production, contracts, procurement, etc. GEIA-HB-0005-2, Technical Guidelines for Aerospace and High Performance Electronic Systems Containing Lead-Free Solder and Finishes Used by aerospace electronic system “suppliers” to select and use lead-free solder alloys, other materials, and processes. It may include specific solutions, lessons learned, test results and data, etc. GEIA-HB-0005-3, Rework and Repair Handbook for Aerospace and High Performance Electronic Systems Containing Heritage SnPb and Lead-Free Solder and Finishes GEIA-HB-0005-4, Impact of Lead Free Solder on Aerospace Electronic System Reliability and Safety Analysis Used to determine, quantitatively if possible, impact of lead-free electronics on system safety and certification analyses, using results from tests performed per GEIA-STD-0005-3

11. GEIA-STD-0005-1, Performance Standard for Aerospace and High Performance Electronic Systems Containing Lead-free Solder (Published) *Used by aerospace electronic system “customers” to communicate requirements to aerospace electronic system “suppliers” – Lead-free Control Plan Influence of Lead-free Soldering on the Defense Industry Products

12. GEIA-STD-0005-2, Standard for Mitigating the Effects of Tin Whiskers in Aerospace In High Performance Electronic Systems (Published) *Tin Whisker Protocols and Procedures Influence of Lead-free Soldering on the Defense Industry Products

13. GEIA-HB-0005-2, Technical Guidelines for Aerospace and High Performance Electronic Systems Containing Lead-Free Solder and Finishes * Used by aerospace electronic system “suppliers” to select and use lead-free solder alloys, other materials, and processes. 200 cycles: SnPb (left) and SAC (right) Influence of Lead-free Soldering on the Defense Industry Products

14. Project documents, test plans, test reports and other associated information will be available on the web:  NASA-DoD Lead-Free Electronics Project: http://www.teerm.nasa.gov/projects/NASA_DODLeadF reeElectronics_Proj2.html  Joint Test Protocol  Project Plan  Final Test Reports Super Resource

15. Influence of Lead-free Soldering on the Defense Industry Products: The Basis for Understanding Lead-free Soldering – The “One” Cell

16. Impact of Lead-free Soldering Processes on Defense Industry Electronic Assembly Practices Agenda: Background Specifications Lead-free Topics of Interest (In No Specific Order!)

17. Influence of Lead-free Soldering on the Defense Industry Products: Process Robustness: Alloy Proliferation Graph Source: W. Liu and N. C. Lee, “Novel Sacx Solders with Superior Drop Test Performance”, SMTAI 2006

18. Influence of Lead-free Soldering on the Defense Industry Products: Process Robustness: Alloy Proliferation Graph Source: G. Henshall et al, “iNEMI Pb-Free Alloy Proliferation Project” SMTAI 2008. The Material Engineers are still playing in the sandbox………

19. Influence of Lead-free Soldering on the Defense Industry Products: Process Robustness Graphic Source: The Lead Free Electronics Manhattan Project – Phase I, Contract # N00014-08-D-0758

20. Influence of Lead-free Soldering on the Defense Industry Products: Process Robustness Photos Courtesy of Celestica

21. Influence of Lead-free Soldering on the Defense Industry Products: Process Robustness Left Photos courtesy of NPL/Bob Willis

22. Equipment Issues - Wave Solder Molten Tin is Corrosive! (Photo Sources:“Lead-Free Technology and the Necessary Changes in Soldering Process and Machine Technology”, H. Schlessmann, APEX 2002 Conference Proceedings and “Real Life Tin-Silver-Copper Alloy Processing”, A. Rae et al, APEX Conference Proceedings, 2003 Corroded Solderpot HardwareCorroded Wave Solder Impeller Influence of Lead-free Soldering on the Defense Industry Products: Process Robustness

23. Equipment Issues - Soldering Irons (Photos “Under The Plating”, American Hakko Products Technical Report, July 2002) 18,000 Soldering Hits! (Sn63 Solder Alloy !) Influence of Lead-free Soldering on the Defense Industry Products: Process Robustness

24. Equipment Issues - Soldering Irons Available Temperatures Ranges Seem Useable Tip Maintenance Becomes More Critical Use of Hot Air Systems Gaining Ground (Graph Source: “Dissolution rates of iron plating on soldering iron tips in molten lead-free solders”, Takemoto et al, Soldering & Surface Mount Technology, Vol. 16, No. 3, 2004 Influence of Lead-free Soldering on the Defense Industry Products: Process Robustness

25. Influence of Lead-free Soldering on the Defense Industry Products: Mixed Metallurgy Test Results: Solder Joint Failure @ 137 Cycles for SAC BGA in SnPb Reflow Process

26. Influence of Lead-free Soldering on the Defense Industry Products: Mixed Metallurgy

27. Large AgSn Platelets

28. Influence of Lead-free Soldering on the Defense Industry Products: Mixed Metallurgy – New Physics ???

29. Influence of Lead-free Soldering on the Defense Industry Products: Mixed Metallurgy SAC BGA Reworked with SAC Solder Paste, Original Solder Joint was SnPb, Magnified View of Crack with Pb Phase Present- Failed after 822 Thermal Cycles

30. Influence of Lead-free Soldering on the Defense Industry Products: Mixed Metallurgy

31. Mixed Metallurgy Interaction of lead and bismuth in a bismuth containing LF solder alloy: Joint Council on Aging Aircraft (JCAA)/ Joint Group on Pollution Prevention (JGPP) LF Solder program. Solder Alloy Included in Test Program: –Sn3.4Ag1.0Cu3.3Bi With SnCu and SnPb TSOP Component –Weblink: http://acqp2.nasa.gov/JTR.htm)

32. What is HOP – incomplete coalescence of the BGA solderball and the solder paste deposit Head On Pillow (HOP)

33. Graph Source: P. Su, “Effects Of Component Warpage On Board Assembly Defects And Effective Mitigation Measures”, SMTAI 2010

34. Head On Pillow (HOP)

35. Graph Source: P. Su, “Effects Of Component Warpage On Board Assembly Defects And Effective Mitigation Measures”, SMTAI 2010

36. Head On Pillow (HOP) – Component Warpage

37. Incorrect Solder Paste Deposit Head On Pillow (HOP)

38. Head On Pillow (HOP) – Incorrect Reflow

39. Pad Cratering Graphic Courtesy of B. Roggeman, Unovis Consortium

40. Pad Cratering

41. Fillet Lifting and Shrinkage Voids Fillet Lifting and Shrinkage Voids Are An Inspection Issue, Not A Reliability Issue

42. Conformal Coating –Silicone Conformal Coat Photo Shown Here. –NOT a Cure-All, Lower Risk. –Conformal Coating Only Captures and Does Not Eliminate. Tin Whiskers Photo Courtesy of Bob Ogden

43. Tin Whiskers Chart Courtesy of Dr. Tom Woodrow, “CALCE Part Reprocessing, Tin Whisker Mitigation and Assembly Rework Symposium”, 2008 Conformal Coating Thickness Plays a Role Have You Characterized Your Coverage Consistency?

44. References You Should Read: 2010 CALCE 4 th Tin Whisker Symposium, Hunt/Wickham Tin Whiskers

45. Soldering Process –Assembly Processes Will Cover Pure Tin on Small Parts with Solder –There Are Geometry Limitations Dependent on Component Construction –Where Is Your Process Data??? Tin Whiskers

46. The Concept of a System of Risk Mitigation Chart Courtesy of CALCE Consortium

47. An Example: Automotive Industry segment: Unintended Consequences of Pure Tin Surface Finishes Photo Source: NASA Engineering and Safety Center Technical Assessment Report, TI-10-00618, “Technical Support to the National Highway Traffic Safety Administration (NHTSA) on the Reported Toyota Motor Corporation (TMC) Unintended Acceleration (UA) Investigation”, January, 2011.

48. Rules Of a Tin Whisker Mitigation Plan Graphic Courtesy of D. Pinsky, Reference: “Controlling Tin Whisker Risk: Implementation of Appropriate Mitigations”, IPC Tin Whisker Conference 2010

49. (Data courtesy of Nihon Superior/K. Sweatman Influence of Lead-free Soldering on the Defense Industry Products: Copper Dissolution

50. ENIG – 1.5mil Copper – 60 SecImSn – 1.5mil Copper – 60 Sec Influence of Lead-free Soldering on the Defense Industry Products: Copper Dissolution

51. Impact of Lead-free Soldering Processes on Defense Industry Electronic Assembly Practices: Conclusions * The implementation of lead-free soldering technology is achievable if conducted in a measured, controlled, methodical manner. * We need significant coordination and collaboration within the military/aerospace industry segment to avoid non-value added efforts

52. Questions ?