振动环境下焊点疲劳失效与裂纹扩展分析

采用子结构方法对振动加载条件下组装有EBGA器件的印制电路板系统进行有限元建模,研究了振动环境下焊点疲劳速率与环境温度、振动频率之间的关系;然后又利用局部/整体相结合的方法对EBGA焊点中由于热循环试验导致的微裂纹在振动试验条件下的扩展情况进行了分析,研究结论可以为HALT试验中振动试验方案的制订以及热循环与振动试验结合方式的优化提供理论指南,最后对分析结果进行了试验验证。

Analysis of fatigue failure and crack propagation of solid joints under vibration load

In this paper, the substructure technique is used to construct the finite element model of the printed circuit board（PCB） which EBGA package has been soldered onto and random vibration loading has been applied, then the influence of environment temperature and vibration frequency on the vibration fatigue life of solid joints is studied. Subsequently an advanced global/local finite element modeling tech- nique is employed to study the add-on effect of random vibration on the solid joint with pre-crack which is induced during thermal cycling test. The research result is helpful to prepare vibration test scheme and combine thermal cycling test with vibration test effectively. At last, the conclusion is validated by test.