Junction temperature estimation of IGBT module via a bond wires lift‐off independent parameter V gE‐np

Abstract

An electrical method for junction temperature estimation of insulated-gate bipolar transistors (IGBTs) is presented in this study. Owing to the parasitic inductance between bond wire and main emitter terminal L E . The temperature-dependent falling collector current during turn-off transition would cause a negative voltage drop in the gate-main emitter voltage waveform v gE . Therefore, this negative voltage drop V gE-np is proportional to the junction temperature. A double-pulse test circuit is developed to verify the accuracy and feasibility of the proposed method. The impacts of collector-emitter voltage V ce , collector current I c and bond-wires cut-off are also be discussed theoretically and experimentally. The experimental results show that the proposed V gE-np has a linear relationship with junction temperature as theoretical analysis and it is a bond-wires cut-off independent parameter in some special test point, which offers an effective way to estimate junction temperature without package destruction. The advantages of the proposed method include good linearity, bond-wires failure immunity and adequate sensitivity with junction temperature.