Abstract
Thermal fatigue life analysis of GaN packages is an important consideration that affects the reliability and durability of electronic devices. In this paper, the fatigue life assessment of a GaN laterally conducting power packaging, including SAC305 and Sn63/Pb37 solders was conducted using the finite element analysis (FEA) method. The thermal cycling loading was chosen based on JEDEC Standard JESD22-A104D condition M. With temperature cycling from −40°C to 150°C. To simulate the viscoplastic behavior of solder materials under thermal cycling, the Anand constitutive model was adopted. Coffin-Manson, Engelmaier, and Solomon empirical models were utilized to predict the cyclic life of the package based on stress and strain distribution in the solder layers. Results showed that the critical solder joint location of the failure was in the SAC305 solder. The maximum inelastic strain range of SAC305 solder was calculated to be 0.023697. The fatigue life prediction of the module showed that the Engelmaier model was the most conservative model resulting in a fatigue life of 136 cycles.
