Influence of interfacial compliance on thermomechanical stresses in multilayered microelectronic packaging

Many analytical procedures are proposed for thermomechanical analysis of layered structures, mostly based on the perfectly bonded interfacial conditions. However, in the microelectronics industry, there is a strong desire to design packages with flexible interfaces to decrease interfacial stresses and interfacial delamination. In this paper, an analytical model based on flexible interfacial compliances is presented for multilayered microelectronic structures where loading can be a thermal gradient across the layers rather than uniform temperature. Interfacial stresses and the normal stresses in the layers can be calculated very efficiently and quickly compared to time-consuming finite-element analysis and following asymptotic analysis. The influence of interfacial compliance on thermomechanical stresses is investigated for different cases.