Effect of interfacial intermetallic compounds morphology on mechanical properties of solder joint with finite element simulation

The morphology of interfacial intermetallic compounds (IMCs) can have serious impact on the reliability of solder joints. This paper investigated the effect of interfacial IMC (Intermetallic Compound) morphology on mechanical properties of solder joint by finite-element method. The joint model is consisted of copper, Cu 6 Sn 5 interfacial IMC and Sn-3.0Ag-0.5Cu solder alloy. The surface of interfacial IMC was simplified into a cyclical one. In finite-element analysis, these joints with different interfacial IMC morphology were extruded to fracture. The results show that there are three stages for load-displacement curve of every kind of joint including quasi-elastic deformation stage, plastic deformation stage, and damage stage. Ultimate tensile load, fracture energy and interfacial crack length are influenced by the surface morphology of interfacial IMC.