Research on Wettability of Sn-3Ag-0.5Cu Alloy on Metal Cu

The effects of heating temperature and holding time on the wettability of Sn-3Ag-0.5Cu solder on Cu substrate and interfacial reaction were studied.The results show that when the holding time is 60 min, with the increase of heating temperature from 275℃ to 350℃, the stable wetting angle of Sn-3Ag-0.5Cu solder drops from 56.0% to 28.1°.It belongs to reaction wetting, Cu₃Sn and Cu₆Sn₅ phases are formed at the interface.With the increase of heating temperature and holding time, Cu element gradually diffuses to Sn-3Ag-0.5Cu alloy, and the thickness of the two phases gradually increases and becomes more uniform.