Effect of Ge on Interfacial Reaction Sn-3.5Ag Alloy/Cu Interface

Effect of Ge on the interfacial reaction of Sn-3.5Ag alloy (SA)/Cu interface was investigated through adding a small amount of Ge (0.1wt%,0.3wt%) into Sn-3.5 Ag emtectic alloy.The results show that the initial phase at the SA/Cu interface without Ge addition was scallop like Cu6Sn5.A new layer,which was determined as Cu3Sn,was formed at Cu6Sn5/Cu interface and grew continously after isothermal aging,and Kirkendall voids were found at Cu3Sn/Cu interface.For SA-xGe/Cu interface,the initial phase was still Cu6Sn5.The growth rate of Cu6Sn5 was decelerated.The Cu3Sn did not form.During aging,no Kirkendall voids were found.