Measuring Temperature Swing with Optical Fibers during Power Cycling of Power Components

Power semiconductor components play an important role in the power electronics field and their reliability and lifetime have been attracting more and more attention recently. The power cycling test method has been widely used to accelerate the degradation of the device and evaluate its reliability and lifetime. This paper presents a power cycling setup based on optical fibers to measure the power module’s chip junction temperature during operation under different loading conditions. The setup has been used to conduct both the DC- and AC-power cycling tests, and the junction temperature measured by the optical fibers during the tests can help to evaluate the thermal stress during operation, indicate the health status of the device under test (DUT) and record its degradation process. Experimental results verified that implementing optical fibers is an effective way of measuring the junction temperature while conducting the accelerating test.