LAUSR

Bonding wires fatigue is a common fatigued mode of power modules, and in situ monitoring of bonding wires fatigue in insulate-gate bipolar transistor (IGBT) modules is highly efficient and economical for improving reliability. In this article, we innovatively propose a monitoring method based on the dual-current probe method to extract the differential mode (DM) impedance of IGBTs and realize the online monitoring of bonding wires with dual-current probe technology for the first time. Taking the Buck converter built by IGBT module as an object, we analyze the influence of parasitic parameters on DM interference signal and investigate the correlation between DM impedance and bonding wires fatigue. A dual current probe is used to measure the changes of DM interference signal in real time to monitor the health status of the bonding wires. The experimental results show that the method does not need to destroy the package, and the fatigue can be evaluated in real time in the frequency band (18–21 MHz), where the DM interference signal changes significantly, with a sensitivity of about $3~\Omega $ /root. Due to the parasitic inductive and capacitive coupling effects in this band, it is sensitive to DM the electromagnetic interference (EMI) signal variations with low noise and attenuation. This method identifies potential faults in a nonintrusive way, improving the reliability and safety of IGBT modules.