不同固定方式下高压功率模块的抗冲击性能分析

High-voltage power module is a key component to realize stable current output. In order to improve the structural reliability of the high-voltage power module and optimize the fixed modes under high-speed impact, the impact resistance characteristics with different fixed modes are studied. Based on the one-dimensional stress wave theory, the comparison of deformation energy and kinetic energy of the module with different fixed modes are obtained by analyzing the dynamic response and energy conversion form of the module on the free Hopkinson pulse bar (FHPB). The finite element method is used to simulate the processes of motion and deformation under impact velocity of 20 m/s. The stress distributions, the deflection curves, the velocity curves, and the acceleration curves of the module under the same impact are obtained. It is found that the maximum stress (427 MPa) appears at the ceramic layer, while the maximum deflection (773.8 μm) occurs at the metal substrate layer. The magnitude of the maximum displacement speed is up to 17.68 m/s, and the magnitude of the maximum acceleration is up to 51 110.7g. By comparing the impact response results of the four fixed modes, the deformation of bottom substrate from small to large is the surface mounting, four-corner point fixing, two-point fixing on the short side and two-point fixing on the long side. The highest kinetic energy and acceleration are produced on the surface mounting modules. The results indicate that a minimum failure probability exists on surface mounting module under high impact loading. In summary, surface mounting is the most reliable fixed method among the four fixed methods. Then, the selection priorities are as following: the four-corner fixing, two-point fixing on the short side and two-point fixing on the long side. Out study results would provide an important theoretical basis of the mounting and fixing methods for semiconductor high-voltage power modules in practical application.