Growth behaviors of tin whisker in RE-doped Sn-Zn-Ga solder

摘要

Purpose - The purpose of this paper is to investigate the growth behavior and mechanism of Sn whisker induced by RE addition in Sn-Zn-Ga-Pr solder at ambient condition. Design/methodology/approach - By means of aging treatment, FIB and SEM microstructure analysis, the whisker growth behavior was investigated. Findings - It was found that the morphologies of tin whisker are changed during air exposure. After 60 days aging, the average length of the longest whiskers could reach up to 70μm, some whiskers even can grow to a length of 100μm. It was discussed that the oxidation of Pr-Sn intermetallics provides driving force for whisker growth. Originality/value - Tin whisker growth is a complex reliability issue for lead-free solder. The current research can be helpful in re-understanding the issue of tin whisker growth as well as an enriched understanding on the effects of REs on lead-free solders.