Design and Simulation of Asymmetric Structure of Packaging Substrate in IGBT Power Module

• Published in: 2024 25th International Conference on Electronic Packaging Technology (ICEPT) pp. 1 - 5
• Main Authors: Jiying, Hou, Jie, Bao, Yunyan, Zhou, Yang, Wang, Ziheng, Li, Zhihao, Yan
• Format: Conference Proceeding
• Language: English
• Published: IEEE 07.08.2024
• Subjects: Asymmetric structure; Cogeneration; Copper; DBC; Electronic packaging thermal management; Insulated gate bipolar transistors; Multichip modules; Residual stresses; Simulation; Thermal stress; Welding
• DOI: 10.1109/ICEPT63120.2024.10668771

Insulated Gate Bipolar Transistor (IGBT) modules, as common power semiconductor devices, are widely used in fields such as wind power generation, solar power generation, electric vehicles, rail transportation, and household appliances. The operating environments for these modules often involve high voltage and high power, which imposes higher demands on the reliability of IGBT modules. This paper establishes a simulation model for a three-phase inverter power module. Initially, the heat sink undergoes reverse pre-bending treatment. Simulation results show a reduction of 77% in residual stress during the welding process, but significant residual stress still remains. In response to this situation, a novel asymmetric structure of Direct Bonded Copper (DBC) substrate is proposed. The thickness of one copper layer of the DBC substrate is fixed, while that of the other layer varies to observe the evolution of maximum stress in the solder layer. It is observed that reducing the thickness of the lower copper layer in the DBC significantly improves the thermal stress issue in the solder layer during welding, at the same time, it will not affect the heat conduction performance of the power module during operation.