Creep-resistant performance of two lead-free solders and comparison with Sn60Pb40 solder

The creep and fracture behaviors of the joints soldered by two lead-free solders, Sn-Ag-Cu-Bi and Sn-Ag-Sb, were studied, and a comparison to the traditional Sn60Pb40 solder was also researched.The results show that the two lead-free solders have much better creep resistant performance than that of the Sn60Pb40 solder, in terms of longer creep rupture lifetime and lower creep rate.The SEM inspection and analysis of the creep fractured joints show that creep fracture of the joints soldered by two lead-free solders presents obviously intergranular fracture mechanism, while creep fracture of the Sn60Pb40 soldered joint presents dominantly transgranular sliding.