Aging monitoring method for bond wires in IGBT modules based on combined TSEPs
摘要
The condition monitoring of bond wires within insulated gate bipolar transistor (IGBT) is critical to ensuring long-term reliability in power converters. However, existing electrical parameter-based monitoring methods are inherently susceptible to junction temperature variations, leading to significant challenges in the accurate aging state assessment of bond wires. Considering that junction temperature estimation using turn-off delay time (tdoff) is affected by bond wire aging, whereas the peak collector-emitter voltage during turn-off transient (VCE_M) provides aging-insensitive thermal characterization, this paper systematically investigates the temperature dependence of both VCE_M and tdoff in IGBT modules, along with their underlying interaction mechanisms with bond wire aging. An aging monitoring method of bond wires is proposed by utilizing the junction temperature difference estimated through these two temperature sensitive electrical parameters (TSEPs). Experimental results show that the proposed method effectively decouples the influence of junction temperature on aging assessment while exhibiting high stability, sensitivity, and accuracy, providing a viable solution for the reliable evaluation of IGBT modules.