As an important device for energy conversion and transmission, the insulated gate bipolar transistor (IGBT) modules attract much popularity in considerable applications. One of the major concerns associated with the IGBT modules is the limited heat dissipation capacity of the existing package design, which may obviously deteriorate the reliability. To address this, a new design method of IGBT module with embedded vapor chamber is proposed in this paper. In this design method, benefiting from the phase transformation process of the liquid material in the vapor chamber, an improved lateral thermal conductivity of the copper substrate is obtained, and accordingly, the junction temperature and the weight of the IGBT module are significantly reduced. Then, the finite element analysis of the proposed design method is performed and performance comparison is made between the proposed design IGBT module and the conventional copper substrate one.