IMPACT FAILURE ANALYSIS OF SOLDER JOINT BASED ON EXPLICIT DYNAMIC METHOD

The component-level high-speed shear test is an important means of studying the reliability of an Sn-Ag-Cu solder joint in an electronic package caused by impact loading. Experimental studies show that the failure of a solder joint structure will transfer from the ductile damage of solders to the brittle fracture of interfacial intermetallic compounds (IMC) with the increase of impact velocity; at the same time, the shape of load-displacement response curve will also have a notable change. In order to better understand the impact failure of the package structure, and further improve its structural design, a new finite element simulation method was proposed. In this method, the progressive damage model was used to simulate the damage process by considering the strain-rate-dependent dynamic hardening characteristics of solders; and a mixed-mode cohesive zone model was developed and used to simulate the brittle fracture of IMC. Comparisons with the experimental results show that the proposed method can effectively characterize the failure behavior of a solder joint structure at different impact velocities.