Study of Gate Bias Voltage for Preventing Threshold Shift of SiC–MOSFET Body Diode during Transient Temperature Measurements

In this paper, a method for determining gate bias voltage condition in transient temperature measurement using SiC-MOSFET body diode is reported. The Vg–Vsd characteristic of the device is investigated and there is a plateau portion where the Vsd did not change against the change of Vg. Transient temperature measurement using the body diode become possible under the gate bias condition of the plateau portion. This method was applied to three devices with different characteristics, and it was confirmed that transient temperature measurement is possible by selecting appropriate Vg according to each device characteristics. The transient temperature of each module in which these three devices were mounted in the same structure package was measured. The three transient temperature graphs agree well, and the three structure function graphs also agree well. By using this method, it is possible to quickly determine parameters of transient thermal resistance analysis for an unknown device.