Study on the mitigation solder of the external stress type whisker

Abstract

External stress type whisker occurs in Sn plating surfaces by external stress. The whisker generated in connector causes short circuit issue. Although various measures are performed for inhibiting whisker, external whisker issue is not resolved completely at this time. In this paper, we found out that some doped tin alloys showed the whisker resistance corresponding to Sn-10Pb alloy. As a result of external stress test of some doped tin plating coupons, where some dopant tin solders were coated by dipping Ni plated Cu coupons into doped solder bath. In addition, we observed the cross-section of plating film in order to investigate the mechanism of whisker restraint.