Influence of Dopant on IMC Growth and Mechanical Properties of Sn-3.5Ag-0.7Cu Solder Joints

This work investigates the effects of Sb on IMC formation and mechanical properties of Sn-3.5Ag-0.7Cu lead-free solder joints. In this work, SEM is used to measure the thickness of intermetallic layer and observe the microstructural evolution of solder joint. The IMC phases are identified by EDX and XRD. Results show that there is a significant drop in IMC thickness when Sb is about 0.8 wt%. The tensile strength of the solder joints can be slightly improved by adding a small amount of Sb in Sn-Ag-Cu alloy system.