Authored By:
Bob Klenke
ITM Consulting
Coeur d'Alene, ID, USA
Summary
In 1983 the Department of Defense (DoD) determined that over 40% of military electronics system field failures were electrical in nature and some 50% of these failures were due to poor solder connections. Plated finishes, usually nickel or tin, were found to be porous and non-intermetallic allowing oxide penetration to the base metal which led to poor solder joint integrity and therefore resulted infield failures. As a result the MIL-STD-883 solderability testing standard was instituted to assure that all components in high-reliability applications were indeed solderable and plated finishes gave way in favor of a hot solder dip finish which provides a fused SnPb homogeneous tin-lead finish.
This paper addresses several testing protocols and methods to enhance solderability including: component solderability test methodologies, gold embrittlement and removal of gold plating, component re-tinning, component refurbishing, and QFN coplanarity.
Conclusions
Solderability is no longer an option for many high-reliability segments of the world's electronics assembly industry. With implementation of the latest Rev F of J-STD-001, solderability testing, gold removal and component retinning have become prerequisites for doing business and remaining competitive in the global electronics marketplace.
Initially Published in the SMTA Proceedings
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