A Power Cycling Test Bench Dedicated to the Test of Power Modules in a Large Range of Cycling Frequency

This paper presents new developments of a power cycling test bench targeted to perform very high numbers of cycles at low DeltaTJ (>10(exp 9) cycles, 10 to 20 deg C). This test bench is based on operation of a bridge inverter in which the power devices are the modules to be tested and induces a power cycling of the power dies in realistic conditions (switching), with a high flexibility. This apparatus makes possible carrying out power cycling conventional tests (low frequency, 0.01 Hz to 0.1 Hz) as well as fast tests by using the temperature variation induced by a medium frequency (10 Hz to 100 Hz) load current adjusted by PWM modulation. The test bench is described briefly and the power cycling modes now available are illustrated by thermal measurements carried out on 1200 V - 75 A IGBT modules with an IR camera. Finally, results of ageing tests at low temperature swing (10 deg C and 20 deg C) are presented.