Physical Model of FS-IGBT Considering Dynamic Avalanche Electrical Characteristics and Analysis of Chip Non-uniform Stress

Dynamic avalanche is the extreme operating condition of IGBT, and it has unique electrical characteristics in the switching off transient. In order to accurately characterize the turn off characteristics of IGBT, this paper proposes an improved method of traditional IGBT turn off physical model for dynamic avalanche phenomenon based on the physical mechanism of dynamic avalanche phenomenon and the multiplier effect after dynamic avalanche formation. Finally, according to the physical model, the uneven distribution of stress on the chip surface is analyzed, which provides the basis for IGBT model establishment and reliability analysis.