Online IGBT Temperature Measurement via Leakage Current in HTRB Test

Abstract

To evaluate the reliability of endure high voltage when IGBT is turned off and eliminate the defective devices, HTRB (High Temperature Reverse Bias) test is one of the necessary tests for IGBT before it’s produced. According to the IEC standard, DUTs (Device Under Test) are usually blocked, and bear forward bias voltage, which is preferably 80% of VCESmax. During the HTRB test, DUT junction temperature should be set at maximum virtual junction temperature Tvj(max) which is usually between 125°C to 150°C. Due to high voltage, even though the leakage current is very low, high-power semiconductor devices generate dissipated power during HTRB test, which lead to junction temperature increase. And to access the reliability accurately, the rise of temperature cannot be neglected. To insure the test is carry out at standard temperature, this paper monitors DUTs junction temperature by using leakage current as a TSEP (Temperature Sensitive Electrical Parameter),. The experiment proofs that higher the junction temperature is, the more accurate the measure results will be, in the operating temperature range. In this paper, thermal resistance measurement is used to evaluate the validity of this method.