Performance of Solder Bond on Thermal Mismatch Stresses in Electronic Packaging Assembly

Abstract

Thermo-mechanical stresses have been considered one of the major concerns in electronic Packaging assembly structural failure. The interfacial stresses are often caused by the thermal mismatch stresses induced by the coefficient of thermal expansion (CTE) difference between materials, typically during the high temperature change in the bonding process. This research work examined the effect of bond layer on thermal mismatch interfacial stresses in a bi-layered assembly. The paper verified the existing thermal mismatch solder bonded bi-layered analytical model using finite element method (FEM) simulation. The parametric studies were carried out on the effect of change of bond layer properties in order to provide useful references for interfacial stress evaluation and the electronic packaging assembly design. These parameters included CTE, temperature, thickness, and stiffness (compliant and stiff bond) of the bond layer. The recent development on lead free bonding material was being reviewed and found to have enormous potential and key role to address the future electronic packaging assembly reliability.