Real-time Bond Wire Lift-off Monitoring via Module Integrated Current Sensors

Giant magnetoresistive (GMR) detectors were integrated in power modules for high-bandwidth current sensing in energy conversion applications. This work proposes methodologies for utilizing the already integrated current sensors for simultaneous monitoring of bond wire lift-offs. No additional hardware is needed. The magnetic field variations caused by the lift-offs are detected by the GMRs in the vicinity of the lifted bond wire. This information is separated from the current sensing signals by two methods. The methods work in real time and have a response as soon as one bond wire is lifted. The methods can also determine which bond wire is lifted. FEAs and experiments are carried out to evaluate the proposed methodologies in a 6-in-1 IGBT.