Investigation of pulse thermal resistance of a semiconductor device

Thermal resistance experiments based on electrical method were carried out on a commercial bipolar junction transistors (BJT) device. After extracting the thermal time constant, duty-cycle dependent pulse thermal resistance of the device were achieved. To verify the calculated results, both static and pulse infrared (IR) thermal imaging measurements were carried out. Good agreements were achieved between calculated and measured results. Knowing both the DC and pulse thermal resistance of a specific semiconductor device allows both the manufacturer and user to determine the junction temperature of the device under any operation state. The results in this study are extremely useful for designing switching type power supplies and improving device reliability.