Indirect In-Situ Junction Temperature Measurement for Condition Monitoring of GaN HEMT Devices during Application Related Reliability Testing

This paper presents an indirect method to estimate the junction temperature Tj of a GaN HEMT device during reliability testing. The method is based on a thermal resistance network and a thermal sensor. The main advantage of the proposed method is that the thermal sensor is not directly attached to the device, which allows the reliability test to run without disturbance or interruption. Furthermore the accuracy of this method is demonstrated by comparing the estimated values and measurements of the junction temperature Tj.