Abstract:Research on the mechanism, evolution rule and condition monitoring of bonding damage of insulated gate bipolar transistor (IGBT) module is one of the important parts in the reliability research of power electronic devices and systems. Firstly, the bonding damage and its evolution trend are analyzed theoretically. It is pointed out that the bonding damage is the result of the synergistic effect of the electrodynamic force on the bonding lines and the shear stress on the bonding points. The positive feedback process of bonding damage evolution is sorted out. Then, the thermalforce field of bonding lines and bonding points of IGBT module is simulated and analyzed to quantitatively explore the bonding damage mechanism and its evolution rules. Experimental results show that both electrodynamic force on the bonding lines and the shear stress on the bonding points are not only the inducement of bonding damage and its evolution, but also obviously affected by them. Furthermore, the equivalent circuit analysis and experiment study are implemented to verify the feasibility of the bonding resistance monitoring method based on the height of miller platform and collector current. Finally, the limitations of the online monitoring method of IGBT bonding resistance in wind power are analyzed and pointed out. The solutions to key problems of online monitoring of IGBT bonding resistance in wind power are put forward, and the online monitoring program is designed. In addition, a fivelevel state assessment method of bonding damage based on percentage increment of bonding resistance is proposed.