Effects of impurities on void formation at the interface between Sn-3.0Ag-0.5Cu and Cu electroplated films

Void formation is a critical reliability concern for solder joints in electronic packaging. The control of microstructures and the quantity impurities Cu electroplated films significantly affect void at joint interface, but studies investigating these factors are rare. In this study, three (denoted as A, B, C) fabricated using an electroplating process. A film has faceted grain texture embedded with twin boundaries, while B C have similar columnar textures. After thermal aging 200 °C 1000 h, SAC 305 (Sn-3.0Ag-0.5Cu) exhibit robust interfacial structures without voids. However, microstructural collapse observed 305/Cu C, where many crevices formed parallel to interface. Based on microanalysis, concentration higher than B. Moreover, discrete voids rather continuous present SAC305/Cu system when impurity reduced. findings demonstrate that void/crevice joints.