NASA-DoD Lead-Free Electronics Project

1. NASA-DoD Lead-Free Electronics Project

2. NASA-DoD Lead-Free Electronics Project • The primary technical objective of the project is to undertake comprehensive testing to generate information on failure modes/criteria to better understand the reliability of: • Packages (e.g., Thin Small Outline Package [TSOP], Ball Grid Array [BGA], Plastic Dual In-line Package [PDIP]) assembled and reworked with lead-free alloys • Packages (e.g., TSOP, BGA, PDIP) assembled and reworked with mixed (lead/lead-free) alloys. Web Link: NASA-DoD Lead-Free Electronics Project: http://www.teerm.nasa.gov/projects/NASA_DODLeadFreeElectronics_Proj2.html

3. Comparison of NASA-DOD LFE Project to predecessor JCAA/JG-PP Project • Similarities • - Virtually identical test vehicle • - Procedures identical for most tests • - Same facility for assembly • - SN100C being used for wave soldering • Differences • - Test articles will be thermally aged after assembly • - Increased rework • - Increased solder mixing • - Mechanical shock test procedure • - Drop testing • - Immersion Ag surface finish for all test vehicles • - SAC305 being used for reflow soldering • - SN100C being used for reflow soldering

4. NASA-DoD Lead-Free Electronics Project Stakeholders

5. NASA-DoD Lead-Free Electronics Project Stakeholders

6. Project Flow

7. Lead-Free Solder Alloys • SAC305 (Sn3.0Ag0.5Cu) • Surface mount assembly • This alloy was chosen for reflow soldering because this particular solder alloy has shown the most promise as a primary replacement for tin-lead solder. The team decided that they wanted to select at least one “general purpose” alloy to be evaluated and it was determined that the SnAgCu solder alloy would best serve this purpose. • SN100C (Sn0.7Cu0.05Ni+Ge) • Plated through hole • Surface mount assembly • This alloy is commercially available and the general trend in industry has been switching to the nickel stabilized tin-copper alloy over standard tin- copper due to superior performance. In addition, this nickel-stabilized alloy does not require special solder pots and has shown no joint failures in specimens with over 4 years of service.

8. Test Vehicle Assemblies 4 Main Categories • SnPb Manufactured • Lead-Free Manufactured • SnPb Rework • Lead-Free Rework

9. Assembly Profiles

10. Assembly Profiles

11. Assembly Profiles

12. Assembly Profiles

13. U64 Test Vehicle

14. Component Finish/Solder Combinations Manufactured Test Vehicles Thermal Cycle & Combined Environments Testing

15. Component Finish/Solder Combinations Manufactured Test Vehicles Thermal Cycle & Combined Environments Testing

16. Component Finish/Solder Combinations Manufactured Test Vehicles Vibration, Mechanical Shock and Drop Testing

17. Component Finish/Solder Combinations Manufactured Test Vehicles Vibration, Mechanical Shock and Drop Testing

18. U64 Components to be Reworked

19. Component Finish/Solder Combinations Rework Test Vehicles Thermal Cycle & Combined Environments Testing

20. Component Finish/Solder Combinations Rework Test Vehicles Thermal Cycle & Combined Environments Testing

21. Component Finish/Solder Combinations Rework Test Vehicles Vibration, Mechanical Shock and Drop Testing

22. Component Finish/Solder Combinations Rework Test Vehicles Vibration, Mechanical Shock and Drop Testing

23. Board Numbers

24. Project Activities

25. NASA-DoD LFE Project Schedule

26. Contributions to the NASA-DoD Lead-Free Electronics Project

27. Still running -20/+80C Thermal Cycle Test Testing will continue until all LF/LF BGA components fail ~ 17,037 cycles completed (April 23, 2007) Lead-Free Projects Schedule

28. Tim Kalt Mark Stibitz Scott Harris Scott Newland Charles Mitchell Thank You Lety Campuzano-Contreras Linda Woody Tom Woodrow Gary Latta Andy Ganster Mick Miller Mike Osterman Jeff Bradford Polina Snugovsky Jeff Kennedy Dave Hillman Jelena Bradic Doug Romm Vance Anderson Marcus Wheeler Jim Blanche Reza Ghaffarian Tetsuro Nishimura Keith Sweatman Marji Baumann

29. NASA-DoD Lead-Free Electronics Project Kurt Kessel ITB, Inc. NASA Technology Evaluation Principal Center (TEERM)  Kennedy Space Center, FL Phone: 321-867-8480 E-Mail: kurt.r.kessel@nasa.gov Website: www.teerm.nasa.gov • Web Links: • NASA-DoD Lead-Free Electronics Project: http://www.teerm.nasa.gov/projects/NASA_DODLeadFreeElectronics_Proj2.html • JCAA/JGPP Lead-Free Solder Testing for High Reliability: http://www.teerm.nasa.gov/projects/LeadFreeSolderTestingForHighReliability_Proj1.html

30. Back-Up Slides OTHER NASA Efforts

31. The NASA Electronic Parts and Packaging (NEPP) Technology Readiness Overview (TRO) Conclusions • We don’t understand lead-free solders nearly as well as we understand SnPb solder • For SnPb, established reliability over 30 years • Advantages of SnPb: • Fully Characterized in Space Applications and Environments • Low Melting Temperature (183 ºC) • Low to No Whiskering • Availability • Low Cost ($1.78/lb)

32. SHUTTLE ENVIRONMENTAL ASSURANCE INITIATIVE (SEA) Lead Free Solder and Electronic Components Risk Assessment and Mitigation Strategies for the Space Shuttle Program Elements The use of lead-free components is rapidly evolving and has become a major driving force in the electronics industry. SEA suggests the following steps to manage the: - Apply the most appropriate mitigation strategy - Continue to collaborate with Avionics - Continue to use SEA lead-free sub team to exchange technical methods and techniques for risk mitigation - Continue to monitor industry for lead-free alternatives - SEA also suggests that new vehicle programs begin the evaluation of lead-free electronics used in specific hardware configurations and possible lead-free alternative testing on future space exploration missions.

33. Proposed Method for Assessing Lead Free Solder Reliability In Space Materials & Processes Laboratory Report Huntington Beach Site Host Engineering

34. Proposed Method for Assessing Lead Free Solder Reliability In Space OBJECTIVE: The objective of this proposal is to describe an effort whereby lead free test articles are fabricated, packaged, and delivered by Shuttle to the Space Station Freedom. It is hoped that this description is enough to generate the Program interest required to pursue the proposed effort. MATERIALS: Materials for evaluating reliability; - Pure tin soldered circuit boards (6 required) - Tin-silver-copper soldered boards (6 required) - Lead soldered control boards (6 required) - Container for housing experimental boards Materials for evaluating whisker formation; - Brass panels plated with bright tin - Brass panels plated with matte tin - Alloy 42 (Iron – nickel) panels plated with bright tin - Alloy 42 (Iron – nickel) panels plated with matte tin

35. Proposed Method for Assessing Lead Free Solder Reliability In Space There are at least two options for locating the testing container. The first option would be to place the container on a shelf outside the Station. Upon completion of the experiment the container would be returned to the Orbiter payload bay for return on a subsequent Shuttle mission. A second placement option would be in an internal location, taking advantage of an unused storage volume. This option, however, would not provide an extreme enough environment to test the specimens Once the test specimens are returned, space exposure will be compared to similar boards left on the ground. Using a chip bond shear tester the effects of space exposure can be quantified. In this test a shear force is applied to surface mounted chips. Degradation of the solder joint causes the chip to part from the board with greater ease.

36. Proposed Method for Assessing Lead Free Solder Reliability In Space DISCUSSION: The results from this experiment will provide the first data of its kind to address the questions of space reliability of lead free solder. By relating space exposure effects to terrestrial exposure, specification requirements for lead free space hardware might be developed. The proposed experiment is not expected to be a costly one since it would utilize standard test boards designed for similar experiments performed on the ground. Use of lead free solder on space hardware, either intentional, or by accident, is an eventual reality. The Shuttle and Space Station offer perhaps the only opportunity to ensure that future hardware performs as expected.

37. There are four dedicated sites on the starboard side of the ISS truss where external payloads can be attached. There are two attach points on the nadir, or Earth-facing, side of the truss, and two on the opposite, or zenith, side. US Integrated Truss Attachments Japanese Experiment Module (JEM) There is also the un-pressurized Experiment Logistics Module-Exposed Section (ELM-ES), which is a storage and carrier module for spare external hardware and user payloads. Columbus Module An Exposed Payload Facility is planned for Columbus. It will consist of two separate support structures attached to the Columbus Pressurized Module end cone in the zenith and nadir positions.

38. US Integrated Truss Attachments Columbus Module Japanese Experiment Module (JEM)

39. Dec. 2006 The port solar arrays are seen in the far left of this picture. STS-117 will install matching solar arrays and truss segments on the starboard side of the space station. Credit: NASA