Physics-based Modeling of Packaging-related Degradation of IGBT Modules

Abstract

This paper proposes an analytical model to fit degradation data of insulated gate bipolar transistor (IGBT), based on physics understandings. Different from the empirical and data-driven modeling, the revealed failure mechanism, crack propagation and metallization reconstruction leading to the smaller bond contact area and the increased resistivity respectively, have been fully considered. With the help of elaborate geometry equivalence for topside interconnection, an analytical equation is established to quantify the contact resistance, and its variation corresponds to the change of on-state voltage. Consequently, the equation build the bridge between these directly degradation-related indicators (crack, resistivity) and accessible data (on-state voltage, current). Moreover, a concise equation is formulated to analyze the crack propagation while fully considering the existing fracture mechanics theory. And another flexible equation is tailored to quantify the influence of the evolution of metallization reconstruction on resistivity. Finally, power cycling testings are conducted with different test conditions, these data verify the improved performance of the proposed model compared to the existing ones.