Optimization and Analysis of Thermal Conductivity Structure for IGBT Module Embedded With the Vapor Chamber

As an important device for energy conversion, insulated-gate bipolar transistor (IGBT) modules are widely used in various applications. Generally, IGBT power modules work in a harsh environment, and their reliable operation is of high importance. However, most of the existing package design methods fail to provide sufficient reliability for IGBT modules. To address this, an optimal package design method for IGBT modules is proposed in this article. In the proposed design method, the vapor chamber is embedded in the copper substrate. Based on this, a satisfactory performance of spreading heat is accordingly achieved. Moreover, a thermal stress analysis of the IGBT power module with the proposed design method is then provided. The analysis under the high load working state reveals the proposed design method can reduce the chip junction temperature by 12 °C. The optimized structure brings lower thermal stress and a more uniform temperature and consequently maintains the reliability of the IGBT power modules. Experimental tests have verified the performance of the proposed optimization design method.

I. Introduction

Features, such as high-voltage resistance and low turn-on voltage drop, make insulated-gate bipolar transistors (IGBTs) power modules widely used in many applications, e.g., renewable energy generation, high-speed train electric traction drive, and high-voltage dc power transmission [1], [2], [3], [4]. However, as one of the components most prone to failure, it has been reported that the failure rate of IGBT has accounted for 37% of the total failure rate of components [5], [6]. Therefore, the reliability analysis of IGBT attracts much attention.