Abstract:

Defense electronics have been traditionally made with tin-lead solder, but the shift to lead-free production in the electronics industry due to government bans on the use of lead is making it difficult to maintain tin-lead solder production. As a result, the majority of electronics are produced with lead-free solder and the electronic components produced for lead-free solder assembly. To continue tin-lead solder production, the defense electronics manufacturers must assess electronic components for tin-lead assembly compatibility and potentially reprocess components. These processes can compromise component reliability and delay defense electronics production. Despite these challenges, there remains a reluctance to adopt lead-free technology due to uncertainty about its performance and the lack of widely accepted performance specifications for lead-free solder.

To address these challenges, the United States Partnership for Assured Electronics, the Solder Performance and Reliability Assurance (SPRA) project, sponsored by the Cornerstone Other Transfer Activity under CIR CS-20-1302 for Lead-Free Defense Electronics Public-Private Partnership, aims to develop a solder agnostic performance specification and handbook for approving the use of solder in printed board assembly production for defense applications. The performance specification sets forth the requirements for solder used to form packaged device terminal to printed board interconnects and provides a verification process for the requirements. To support the performance specification and support adoption of new solders, a handbook to address concerns related to solder has also been drafted. This paper will discuss details of the performance specification and handbook.

This article is available online here and to CALCE Consortium Members for personal review.