Fatigue Crack Growth in Lead-free Solder Joints

Abstract

This paper investigates the fatigue crack growth behaviors of lead-free solder joints. Metallurgical interactions occur between solders and electrical pad metals in fabrication process and these intermetallic compounds continue to grow during service periods. Due to its brittle nature and lattice mismatch, the solder cracks tend to be generated near the compounds and these cracks affects the mechanical integrity of solder joints. Therefore, it is important to study the effect of intermetallic compounds development on the mechanical properties of the solder joints. In this paper, we focused on the low cycle fatigue of solder joints and investigate the effects of intermetallic compounds development on the fatigue life and the fatigue crack growth behavior of the solder joints.