Experimental Behavior of Single-Chip IGBT and COOLMOS Devices Under Repetitive Short-Circuit Conditions

This paper presents the behavior of single chip IGBT (Insulated Gate Bipolar Transistors) devices under repetitive short-circuit operations. 600V and 1200V NPT (Non Punch Through) IGBTs as well as 600V COOLMOS T M have been tested. The repetition of these severe working conditions is responsible for devices ageing and results unavoidably in the components failures. A serial of experimental tests was made in order to determine the number of short circuit operations the devices can support before failure for different dissipated energies. The temperature influence has been also investigated. Results show two distinct failure modes depending on the dissipated energy during the tests. A critical value of short-circuit energy has been pointed out which separates these failure modes. Experimental and numerical investigations have been carried out in order to analyse these failure modes. A detailed analysis of the physical mechanisms occurring during the short-circuit failures for dissipated energies equal or lightly higher than the critical value is presented.