芯片封装参数对功率模块热特性影响的研究

由于温度分布不均匀以及封装中各层材料之间的热膨胀系数不同,使功率模块在工作中产生交变的热应力,造成焊层疲劳、键合线脱落等失效形式,因此研究模块的热特性尤为重要。热的测量是电力电子系统中最困难的工作之一,对封装结构进行电-热-力精确的仿真分析,能够准确了解对器件不同部位的温度、应力分布。采用基于电-热-力多物理场的有限元仿真,研究了封装材料、封装参数和封装结构对功率器件的温度、热阻、热应力这些热特性的影响,为优化封装设计,最终提高功率模块可靠性提供了一定的参考。

Influences of Chip Packaging Parameters on Thermal Characteristics of Power Modules

It is particularly important to study the thermal characteristics of power modules because alternating thermal stresses, which caused by different coefficients of thermal expansion of different package material layers in power module, can lead to solder layers fatigue, bonding wires off and other failure modes. Heat measurement is one of the most difficult tasks in power electronic systems. The accurate simulation analysis which aimed at the electric-thermal-mechanical performances of the module package structure can accurately obtain the temperature and stress distribution in different parts of the device. In this paper, the impact of package materials, package parameters and package structure on the thermal characteristics such as the temperature of the power devices, the thermal resistance and the thermal stress is studied based on electric-thermal-mechanical multi-physics finite element simulation, which can provide references to improve the reliability of power modules by optimizing the package design.