A Non-intrusive Study On Health Monitoring In Bond Wires Of SiC Power MOSFET Modules Based On Three-dimensional Transmitted Magnetic Field Data

Metal oxide semiconductor field effect transistor(MOSFET)is one of the most commonly used switching devices in power electronic system.As the core device,its failure may lead to the interruption of system operation,and even cause serious safety accidents and economic losses.In recent years,with the appearance of the third-generation wide band gap semiconductor represented by silicon carbide(Si C),the device performance has been greatly improved,but at the same time,it brings new challenges in reliability.Health monitoring technology can accurately reflect the health status of power devices in the process of converter operation,which is an important way to effectively solve its reliability.In this paper,the failure of bond wires in Si C power MOSFET modules is studied,and a non intrusive Si C MOSFET bond wires fracture detection method based on three-dimensional transmission magnetic field data is proposed.In theory,the change of the transmission magnetic field around the bond wires after the health problems of bond wires arise is analyzed,and the experimental platform of magnetic field detection is established.In the experiment,the change of the transmission magnetic field around the bond wires after the failure is captured,which verifies the feasibility of the method.This paper first introduces the physical characteristics and failure mode of Si C MOSFET module,and analyzes the impact of bond wire fault on Si C MOSFET module.The damage mechanism and evolution law of the bond wire are given.The positive feedback process that the bond wire resistance affects the reconstruction of the bond wire current and eventually leads to the complete loss of the bond wire is introduced.The core principle that the redistribution of the bond wire current leads to the change of the magnetic field around the bond wire is introduced in detail in the following theoretical and simulation analysis.The change process of the transmission magnetic field caused by the reconstruction of the bonding current in the aging process of the bonding wire is understood.In order to verify the feasibility of the method,an experimental platform was built to detect the magnetic field around the power module for experimental demonstration.The experimental extraction of magnetic field data in the bond wire failure positive feedback process,including the bond wire cracking to the bond wire breaking to the bond wire completely falling off,was completed,and the three-dimensional surface of the transmission magnetic field above the bond wires was established based on the data The experimental results show that the health status of the bond wires of Si C power MOSFET module can be judged according to the change of the three-dimensional surface based on the data of the module transmission magnetic field,so as to realize the non intrusive health monitoring method has high feasibility.This study proposes a new non intrusive health monitoring method for power modules from the perspective of magnetic field,which solves some problems of isolation and real-time in traditional research methods,and opens up a new research perspective for the future research of power device reliability.