振动环境下功率模块的应力形变响应分析与寿命预测

Stress Deformation Response Analysis and Life Prediction for Power Modules Under Vibration Environment

针对功率模块在振动环境中的可靠性问题,建立了4组分别采用铝、铜、金、银材料键合线的功率模块模型,并采用有限元仿真软件对4组模型进行了模态分析、谐响应分析以及随机振动分析。分析结果表明,键合线的材料对模块前4阶固有频率的影响很小,但是对功率模块在振动环境下的可靠性有明显影响,4组模块的共振频率基本相同。在安装位置为“发动机架”的随机振动载荷下,键合线是最容易失效的部位。同时运用基于Steinberg模型的疲劳寿命理论对4组功率模块进行了寿命预测。计算结果表明,在4种材料的键合线中,银键合线的振动疲劳寿命最长。

Aiming at the reliability issue of the power module under the vibration environment,four groups of power module models with aluminum,copper,gold and silver bonding wires were established.Modal analysis,harmonic response analysis and random vibration analysis were carried out on the four groups of models by finite element simulation software.The analysis results show that the bonding wire materials have little effect on the first four natural frequencies of the modules,while have a significant effect on the reliability of the power modules under the vibration environment.The resonant frequencies of the four groups of modules are basically equal.Bonding wires are the most prone to failure in the application scenario of"engine-mounted parts"random vibration loads.Meanwhile,the fatigue life theory based on the Steinberg model was used to predict the life of the four groups of power modules.The calculation results show that the vibration fatigue life of the silver bonding wire is the longest among the four materials.