A technique for the in-situ experimental extraction of the thermal impedance of power devices

In this letter, an innovative technique is presented, which allows the experimental extraction of the junction-to-ambient thermal impedance (ZTH) of power devices operating in their application environment (in situ). The technique draws inspiration from the thermal characterization of RF transistors, and is based on simple measurements of electrical signals, while not requiring a thermochuck, the calibration of a thermometer, as well as temperature sensors or IR cameras. The validation of the technique is unambiguously performed by applying the "simulated experiments" strategy on an SiC-based multichip power module.