关键词: 功率器件, 空洞, 结温, 应力, 有限元分析

Abstract: The voids in the solder layer will lead to the increase of junction temperature and stress during the application of power device, so as to reduce the reliability and service life of the device. The influence of voids varies by size and position. The junction temperature and stress of voids with different sizes at different positions are calculated by Ansys. At the same time, the three-dimensional relationship diagram between junction temperature / stress and the size and position of voids is established, which provides guiding significance for not only evaluating the quality of existing technology by voids regulation but also reducing the influence of voids on junction temperature and stress. The results show that the larger the void size is, and when the void is located at the center or edge of the solder layer, the greater the influence on the device will be.

Key words: power devices, voids, junctio ntemperature, stress, finite element analysis