Assessment of refinishing processes for electronic components in high reliability applications

Refinishing of electronics components, also known as hot solder dip (HSD), is sequence of process steps used to remove original solder alloy coatings from package terminations and replacing the finishes with different type of solder composition. Typically this transformation is from lead-free to eutectic tin-lead solder and aims primarily at mitigating the risk of tin whiskers induced failures. Hot solder dip process is the only practical solution for Aerospace, Defence and High Performance (ADHP) industries which are exempt from lead-free legislations and therefore can adopt this post-manufacturing practice as a strategy for making commercial-of-the-shelf (COTS) components usable in electronics assemblies with high reliability and critical safety requirements. Hot solder dipping has a thermal impact on processed components. Assessing the thermo-mechanical response of components to the refinishing process and their susceptibility to damage is an issue of critical importance. This paper presents the scope of a comprehensive experimental study that aimed at assessing the impact of the thermal shock induced from double dip hot solder dip process on different component types and reports on the findings in relation to their vulnerability and subsequent long-term reliability.