Thermal Transient Tests with Programmed Powering on Wide Bandgap Power Devices of Non-Monotonous and Time-Variant Characteristics

Thermal transient testing of semiconductor devices needs a well-defined power level for heating and proper data acquisition for recording the change of a thermally sensitive device parameter. While the latter is fully solved by up-to-date thermal testers, power level setting is typically limited to forcing varying current levels on two pin devices, such as diodes. Other proposed methods need trials for setting the power and have poor stability.The paper presents a methodology for applying power in various test arrangements, on devices with three pins such as MOSFETs, IGBTs, BJTs and HEMTs. A simple analog circuitry is proposed which ensures thermally and electrically stable powering and an exact operating voltage and current.Several simulation and measurement experiments prove that a novel solution based on fast drain-source voltage change at constant current ensures optimal powering in reliability tests and short electric distortion in transient tests.