Accelerated active high-temperature cycling test for power MOSFETs

In this paper reliability test equipment is presented that allows accelerated failure tests of packaged Power MOSFETs (e.g. TO220, TO263). The failure criterion used is an increase in thermal impedance which is observed in-situ during testing. The duration of the cycles depends on the shift of the junction temperature TJ: Testing with a temperature shift of T J,min = 70°C to TJ,max = 170°C takes for 12 devices and 1 million cycles about 18 days. Thermo-mechanical Finite Element simulations and failure analysis accompany and support the experimental results. The paper gives an overview over the set-up and the measurement technique and discusses the outcome of simulation and test.