Evolution of Ag<inf>3</inf>Sn compounds in solidification of eutectic Sn-3.5Ag solder

Abstract

The relation between cooling rate and morphology of Ag 3 Sn IMCs was investigated in this study. The morphology of Ag 3 Sn intermetallic compounds of eutectic Sn-3.5Ag solder was investigated after solidification at different cooling rates. As the nucleation time of Ag 3 Sn depended on cooling rate, the morphology and size of Ag 3 Sn compounds were affected by cooling rate. The three types of Ag 3 Sn compound during different cooling rate solidification were found to be particle-like, needle-like, and plate-like in Sn-3.5Ag solder. The results show that as the cooling rate decreases, the morphology of Ag 3 Sn formed in Sn-3.5Ag solder transforms progressively from particle-like to plate-like.