Innovative instrumentation for HTRB tests on semiconductor power devices

An automated system designed to perform reliability tests on power transistors is reported. An innovative non-standard procedure for High Temperature Reverse Bias complemented with Electrical Characterization Test based on the division of the total stress time in several short periods is proposed. Thanks to a purposely designed mini-heater the system controls the individual chip temperature on the device under test when testing many devices at the same time. Electrical parameters can be periodically measured to identify early warnings of failure and stopping the same test avoiding an uncontrolled thermal runaway process. When such event occurs the test was stopped only for the involved devices.