A Novel Approach to Model and Analyze Uneven Temperature Distribution among Multichip High-Power Modules and Corresponding Method to Respecify Device SOA

As the most widely used power semiconductor devices, insulated gate bipolar transistor (IGBT) modules are normally composed of parallel IGBT chips to achieve the desired current capability. However, the electrothermal behavior of each chip is significantly different due to the asymmetric layout, increasing the overheating risk of single chip. Therefore, this article proposes a novel approach to describe the thermal safe operation area of multichip IGBT modules in the inverter application, considering the uneven temperature distribution among parallel chips. The novelty of the approach is that it applied the proposed analytical model describing the uneven electrothermal behavior, thus avoiding the traditional averaging process. Comprehensive investigation has been made to reveal the deep mechanism of the inconsistent temperature distribution, which are the uneven dynamic current sharing and thermal cross-coupling effects. Correspondingly, the analytical model of the uneven switching loss and the standard form of thermal resistance matrix related to cooling performance are proposed and further verified, respectively. Based on the proposed approach, the recommended operation area of different rated devices is fully described. The contribution of this article enables more well-founded device selection to achieve a safe and cost-efficient design for the inverter application.