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QUARTERLY TECHNICAL PROGRESS REVIEW

TASK TITLE: Reliability of Pb-free solder alloy studySUBTITLE: Hand soldering process of Sn/Ag alloyQUARTER: 4 FY02 CENTER: GSFCPROGRAM AREA: NEPP/EPAC TASK MANAGER at GSFC: Harry Shaw and Jong KadeschFY02 FUNDING: $40K

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TASK DESCRIPTIONReliability of Board Level Pb-free Solder joints

Compare reliability of interconnection between the conventional eutectic Sn/Pb solder vs. Pb-free solder alloy. The choice of Pb-free alloy is Sn/Ag. GSFC is evaluating the solder joints using hand-soldering process. JPL is evaluating the solder joints using reflow soldering process.

Compare reliability of interconnection between the conventional eutectic Sn/Pb solder vs. Pb-free solder alloy. The choice of Pb-free alloy is Sn/Ag. GSFC is evaluating the solder joints using hand-soldering process. JPL is evaluating the solder joints using reflow soldering process.

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GOALS/OBJECTIVES Reliability of Board Level Pb-free Solder joints

• Identify a candidate of Pb-free alloys based on a literature search

• Validate Hand-soldering assembly process: soldering process, usage of flux, selection of soldering guns temp.

• Compare the solder joints between Sn/Pb solder vs. Pb-

free solder alloys: optical solder joint comparison after

cross-section.

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DELIVERABLES Reliability of Board Level Pb-free Solder joints

Presentation slides that summarize the soldering process comparison between Sn/Pb and Sn/Ag. Also include comparison of solder joint in appearance between two alloys and cross-section microstructure of solder joint.

Presentation slides that summarize the soldering process comparison between Sn/Pb and Sn/Ag. Also include comparison of solder joint in appearance between two alloys and cross-section microstructure of solder joint.

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SCHEDULE Reliability of Board Level Pb-free Solder joints

Major Milestone Q1 Q2 Q3 Q4 Identify and selection of Pb-free solder alloyProcurement of solder alloy, components, and boards

Assembly process - hand-soldering of mounting componentson the board

The assembled boards are subjected to the environmental testing and cross-section specimen.

Prepare technical report for the test result.

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BUDGET/WORKFORCE Reliability of Board Level Pb-free Solder joints

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MAJOR ACCOMPLISHMENTS THIS QUARTER Reliability of Board Level Pb-free Solder joints

Optical images of cross-sectional analysis of:

63Pb/37Sn solder on tin plated boards

97Sn/3Ag solder on ENIG boards

Preparing final presentation slides

Optical images of cross-sectional analysis of:

63Pb/37Sn solder on tin plated boards

97Sn/3Ag solder on ENIG boards

Preparing final presentation slides

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METRICSReliability of Board Level Pb-free Solder joints

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PLANS FOR NEXT QUARTER Reliability of Board Level Pb-free Solder joints

2nd board assembly for temperature cycles Selection of temperature cycle oven Starting temperature cycles between -55 °C and 125 °C

2nd board assembly for temperature cycles Selection of temperature cycle oven Starting temperature cycles between -55 °C and 125 °C

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PROBLEMS AND CONCERNS Reliability of Board Level Pb-free Solder joints

None None