Studies of tin whisker growth under high external pressure

In this study, a series of factors that may affect whisker growth on electroplated tin coatings under high external pressure were studied by an indentation method, including storage time, coating thickness, loading and ball diameter. The indentation test results showed that longer storage time, thicker coating (< 3 μm), heavier loading and smaller inert ball could accelerate whisker growth. In addition, the insertion force, retention force and whisker behavior of compliant press-fit pins inserted into the same design of plated through holes with three different types of final finishes (Immersion tin, ENIG and OSP) were investigated.