Accuracy Comparison of Temperature Sensors for the Thermal Characterization of GaN Transistors

Increasing the power density of electronic systems requires improved thermal management to ensure reliability, which in turn requires accurate thermal measurements to evaluate and optimize systems. This paper compares temperature sensors for thermal characterization of gallium nitride transistors, using methods like infrared cameras, fiber-optic sensors, thermocouples, temperature-sensitive electrical parameters, and 3D thermal simulations. The results reveal significant variations in thermal impedance curves, with thermal resistance varying by up to 43% depending on the sensor and thus the measurement point. The most accurate and responsive measurements were provided by the fiber-optic sensor and electrical parameters, while the thermocouple and infrared camera lacked sufficient temporal resolution.