A simple technique for measuring the thermal impedance and the thermal resistance of HBTs.

This paper presents a new and simple method for characterizing the thermal behavior ofHeterojunction Bipolar Transistors, based on DC, AC andlow frequency small signal measures of H (hybrid)parameters. Static characterization of the thermal behavioris achieved through the calculation of a thermal resistance, while a thermal impedance is used to describe thermaldynamic behavior. Validation results for the method obtained from both simulations and experimental data areincluded in the paper for a 10x2x40 µm InGaP/GaAs power HBT