Influences of intermetallic compounds morphologies on fracture behaviors of Sn-3Ag-0.5Cu/Cu solder joint

In this study, the influences of intermetallic compounds Cu6Sn5at interface between solder and Cu substrate and Ag3Sn inside solder with different morphologies on the fracture behaviors of Sn-3Ag-0.5Cu/Cu solder joint were investigated. Cu6Sn5grains became large in size with the increase of reflow time and aging procedure. Ag3Sn compounds appeared particle-like or branch-like morphologies as reflowed. However, some Ag3Sn compounds evolved into big rod-like shape after aging. The tensile results suggested that the strength of solder joint decreased with these evolvements of intermetallic compounds.