Design and Development of a Measurement System Dedicated to Estimate the Junction Temperature of Insulated Gate Bipolar Transistor Modules

The damage state estimation of an Insulated Gate Bipolar Transistor (IGBT) power module requires the measurement of the junction temperature (Tj) of the active region. However, the accurate measurement of the temperature Tj is not simple to achieve and several methods have been developed to improve the accuracy of Tj measurements. Some of the well-known methods include the use of thermo-sensitive electrical parameters (TSEP). Although the TSEP methods do not provide access to the thermal mapping of the IGBT surface, they have the advantage of not affecting the physical integrity of the module. This paper aims to present a reliable programmable measurement system dedicated to estimating with great accuracy the thermal performance of the IGBT power module on the microsecond scale using the TSEP method. The advantage of this system is to provide full control of the injection of the power current and allows quick measurements of the cooling curve just after the injection of the heating power in the chip. The junction temperature calculated from the TSEP was found to be equal to 97.5 °C, which was confirmed by using the thermal camera. The accuracy of the proposed technique was found to be less than 2%. A comparison with the thermal Resistor-Capacitor (RC) network model is also carried out in this work. Experimental results demonstrate that the designed system is high efficiency and can, therefore, be used by scientific researchers and industrial engineers for predictive maintenance to monitor the performance state of IGBT power modules, which will reduce the probability of its failure or degradation.