Comparison of Whisker Growth from Pressure-Induced and Environment-Induced Whisker Growth Test Methods

摘要

One of the remaining challenges associated with the use of lead-free materials in electronics is the potentialrnfailure risk associated with tin whiskers. Despite intense research in recent years, there are still no accelerated testrnmethods to reliably predict whisker growth in field application conditions. Semiconductor component and electronicrnsystem manufacturers rely on a set of environmental exposure conditions defined by industry standards to qualifyrnand monitor plating processes. While these test methods offer a common platform for package qualification, theirrnvalue for quantitative whisker-induced failure risk assessment is quite limited. Additionally, these tests are timeconsumingrnand labor intensive, making it difficult to use for purposes such as process improvement, control, andrnmonitoring.rnIn this paper, a mechanical indentation method is evaluated for assessing the whisker growth propensity of tin andrnselect tin alloys plated on copper, brass, and alloy 42 substrates. Indentation-induced growth results are comparedrnwith responses to standard test conditions including temperature cycling and elevated temperature and humidity.