LEAD-FREE SOLDER (Continuation of an FY08 Task) Description:FY09 Plans: -Reliability data on lead-free solder applications for various part lead finishes and board finishes -Update lead-free solder risks and risk mitigation strategies for NASA -Evaluate lead-free alloy/lead-free finish reliability in design application -Status CAVE project on Pb-free solder aging effects Costs: Deliverables: NASA/DoD lead-free solder follow-on project status MSFC Lead-free lessons learned report Report on lead-free alloy/lead-free finish reliability Lead Center/PI: MSFC/Mark Strickland/Jim Blanche Co-Is: Center Funding Split: NASA and Non-NASA Organizations/Procurements: Support the responsible NASA official for lead-free solder evaluation Serve as the NASA technical liaison to the NASA/DoD Pb- free Project Assure NASA areas of interest are included in JG-PP follow- on work Support NASA/DoD telcons and face-to-face meetings Publish a comprehensive MSFC lead-free solder lessons learned report

LEAD-FREE SOLDER (Continuation of an FY08 Task) Lead-free Technology Experiment in a Space Environment (LTESE) Procurements funded by MSFC/ES from exchange sale funds (NEPP used for FTE support) Configuration: One Im-Ag board with Pb-free parts using Pb-free solder One SnPb board with Pb-free parts using SnPb solder One SnPb/SnPb control board One data acquisition board Pb-free test parts are: PBGA256's with a SAC405 finish CSP100's with a SAC405 finish 0805 zero ohm resistors with a SAC305 finish QFP100's with 100% Sn finish PDIP14's with 100% Sn finish Sn 63 with an Sn 63 profile has been used to solder the Pb-free parts into the SnPb boards SAC305 solder (Kester EN 907) has been used for the Pb-free boards 7”7” 4.25” 0.93” Expected Results: Intermetallic Compound (IMC) formation under near zero gravity and various temperatures depending on where package is located. Evaluate solder joint life under temperature extremes. Effects of launch and reentry dynamics. Tin whisker growth under known space conditions. Possibly the formation of tin pest

LEAD-FREE SOLDER (Continuation of an FY08 Task) NASA/DoD Lead-Free Solder Project This testing project will build on the results from the JCAA/JGPP LFS Project focusing on the rework (Rwk.) of SnPb and lead-free solder alloys and will include the mixing of SnPb and lead-free solder alloys. GOALS: Generate reliability data for circuit cards manufactured and reworked with SnPb and lead-free solders and subjected to rigorous environmental exposure conditions. Provide baseline data for aerospace and defense (high-performance) applications. Key Question Being Addressed To what extent do rework procedures, including SnPb and lead-free mixed solder joints, affect solder joint

LEAD-FREE SOLDER (Continuation of an FY08 Task) EFFECT OF AGING ON LEAD FREE RELIABILITY CAVE, Auburn University The Electronics in NASA missions and Other Applications are Often Subjected to Long Term Exposures at Extreme High and/or Low Temperatures Extreme Degradation of the Mechanical Behavior of Lead Free Alloys Subjected to Isothermal Aging has been Demonstrated –Reductions in Strength up to 50% –Increased in Creep Rate up to 5000X –Effects Much Stronger Than Seen in Sn-Pb Alloys, and is Present for both Elevated Temperature and Room Temperature Aging Project Concept: Explore Aging Effects on Reliability –Subject Samples to Aging Prior to Accelerated Life Testing (ALT) Multiple Aging Temperatures (Cold and Hot), e.g C, -200 C, -100 C, +25 C, +100 C, +125 C, +150 C, etc. Multiple Aging Durations, e.g months –Compare ALT Reliability Data for Aged and Non-Aged Samples –Understand New Failure Modes for Aged Samples –Develop Degradation Models for Aging