Junction Temperature Measurement Method for SiC Bipolar Junction Transistor Using Base–Collector Voltage Drop at Low Current

Abstract

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.