Validated Solder Coverage for Tin Whisker Mitigation of 0402 Ceramic Capacitors: An Exercise in Technically Sound Cost Reduction
Author: Bruce M. Misner Company: Orbital ATK, Defense Electronic Systems Division Date Published: 9/1/2016
Abstract: Most Department of Defense (DoD) programs demand tin-whisker mitigation to enhance long-term reliability. This typically necessitates tin-lead (Sn/Pb) solder dipping of tin plated components to combine the tin with at least 3% lead. This technique has been proven throughout the industry to mitigate tin-whisker growth [1,2,3]. As a cost saving measure, a project was designed for 0402 capacitors to validate Sn/Pb solder coverage from conventional SMT soldering operations is equivalent to solder dipping. This paper presents the micro-sectioning, extensive X-Ray Florescence (XRF) testing and supporting analysis to demonstrate a cost-effective, 5 sigma process to mitigate tin whiskers can be achieved in lieu of solder dipping.
Tin Whisker, Validated Solder Coverage, Mitigation, XRF, Micro-section, Variability