In Situ Diagnosis of Wire Bonding Faults for Multichip IGBT Modules Based on the Crosstalk Effect

Introducing bond wire diagnosis for multichip insulated gate bipolar transistor (IGBT) modules is key to the health monitoring of modular multilevel converters (MMCs), which allow for improved field robustness, reliability, and reduced maintenance cost. This article leverages the crosstalk phenomenon during switching transitions to detect the chip open-circuit faults caused by the bond wire lift-off using typical half-bridge IGBT modules in a multichip-parallel configuration. The cycle-controlled, nonintrusive measurement is conducted under normal operation, when the device under test is in OFF-state and its complementary switch is during switching transitions. Two specialized health-sensitive parameters arising from the dynamic gate loop waveforms are identified and evaluated, including: 1) the gate voltageVGE(t3)when the declining collector voltage reaches zero and 2) the negative peak gate voltageVGE(t4). The sensitivity and stability of these two parameters are compared through theoretical analysis, circuit simulation, and practical verification. The results show thatVGE(t4)is more suitable for online monitoring, whileVGE(t3)is more sensitive thanVGE(t4). With managed complexity in gate drives, this proposed health awareness approach is feasible in the submodules of MMC applications, but it can also be used in other power converter topologies incorporating the half-bridge structure.