Abstract
This paper discusses the issues of tin whisker growth on discrete electronic components. It presents both a critical analysis of existing published documents on tin whisker nucleation and growth and a summary of very recent experiments that provide further understanding of the potential means of whisker formation mitigation. Many of the proposed techniques for reducing the likelihood of whisker formation are inadequate, including control of the immediate underplating material, use of conformal coating, regulating the thickness of the tin coating, use of matte tin electroplating, and annealing or fusing of the tin layer. They likely reduce the incidence of nucleation or growth but do not provide guaranteed protection from lack of whisker formation. The first report of tin whiskers on electronic components dates back to 1946 [16]. Since that time whisker-related problems have been reported consistently. Today the concern is for the of increased number of whisker-related problems due to circuit geometry reductions, lower application voltages and the probability of more suppliers (rapidly) introducing pure tin plated alternatives to comply with pending Pb-free legislation.
