Research on the Oscillation Mechanism of Insulated-Gate Bipolar Transistor in Short-Circuit Test

The oscillation of gate <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$V_{GE}$</tex>, collector-emitter VCE and short circuit current is caused in the process of parallel short circuit desaturation from the start to the short circuit pulse of IGBT module. In this paper, the oscillation mechanism of parallel devices <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$V_{CE}$</tex>, V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GE</inf> and Isc is analyzed based on the resonant circuit composed of nonlinear capacitance and loop inductor in IGBT short-circuit depletion region. Secondly, the short-circuit test platform of IGBT module is set up to analyze the short-circuit test results of single and parallel modules. The results show that the chip carrier concentration and loop parasitic inductance are the main problems causing IGBT parallel oscillation. Finally, the front and back processing conditions of the power device are optimized to solve the oscillation problem of the IGBT device.