Effect of Ni barrier on the tin whisker formation of electroplating Sn on lead-frame alloy

Electroplating matte Sn has attracted much attention in the lead-free age. To prevent a growth of tin whiskers from lead-frame supported matte tin films, various mitigation methods have been reported. In this work, pure matte Sn was electroplated onto C194 alloy, and electroplating Ni film was used as barrier between matte Sn and lead-frame alloy. The microstructures of the Ni/Sn depositions and tin whisker growth were investigated through using scanning electron microscope (SEM). It was found that the Ni barrier layer played an important role in suppressing the growth of tin whiskers.