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In the article, a new thermal resistance measurement method for GaN high electron mobility transistor (HEMTs) is proposed based on temperature sensitive electrical parameter (TSEP) with the use of MOS switches to connect the drain–source at the beginning of the measurement processes. Compared with traditional methods, the connection of the source and drain reduces the delay caused by the matching circuit. In our experiments, we measured a GaN HEMT at 48 V with a power consumption of 5.28 W. The delay time was less than 2~μs , and the thermal resistance was 9.85 °C/W. We also measured the thermal resistance at the same current-different voltages and different voltages-same power. The results show that the thermal resistance of the GaN HEMT increases with the increase of the power and voltage. Furthermore, the results have been verified by infrared (IR) and simulation methods. Compared with Raman thermography and IR, this method can conveniently measure the thermal resistance of GaN HEMTs without breaking the package, and the temperature accuracy was ±2 °C or better. And the thermal resistance information of each layer of structure, such as the chip-solder-carrier, can be extracted by structural function method to improve the thermal design of GaN HEMTs. [ABSTRACT FROM AUTHOR]

This paper proposes an electrical method for estimation of the vertical junction temperature of silicon carbide bipolar junction transistors (SiC BJTs). This measurement method is based on measurement of the base–collector voltage (VBC) drop at a low current (VBC(low)) during the turn-off process. This voltage shows both good sensitivity and linearity with respect to temperature. The traditional temperature-sensitive electrical parameter VBE(low) (i.e., the base-emitter voltage at a low current) and an infrared camera are used to compare the characteristics of VBC(low). The results show that use of VBC(low) provides more accurate junction temperature and thermal resistance measurement results, which can then be used to extract the vertical junction temperature of the SiC BJT under test. [ABSTRACT FROM AUTHOR]