The lifecycles of vehicular resistor lead in random vibration environment were analyzed in this technical note and the finite element model of a vehicular printed circuit board (PCB) was established. It is with two short edges of PCB fixed for boundary condition to simulate the actual working conditions of the vehicle driving on the road, the constrained modal analysis was simulated and experimental verification were carried out. Both the PCB and the vehicular resistor which soldered on PCB were excited vertically according to Standard GJB150. Based on simulated vibration excitation environment, the power spectral density (PSD) stress value of the resistor lead was calculated. The lifecycles of the resistor lead were calculated theoretically and were verified by following failure-oriented accelerated testing (FOAT). Finally, in order to extend the lifecycles of resistor lead, an improved solution for PCB is put forward.

本文分析了随机振动环境下车载电阻引线的生命周期，并建立了车载印刷电路板（PCB）的有限元模型。以PCB的两个短边固定为边界条件，模拟车辆在道路上行驶的实际工况，进行约束模态分析并进行实验验证。PCB和焊接在PCB上的车载电阻均按GJB150标准垂直励磁。基于模拟振动激励环境，计算电阻引线的功率谱密度（PSD）应力值。电阻器引线的生命周期从理论上进行了计算，并通过以下面向故障的加速测试（FOAT）进行了验证。最后，为了延长电阻引线的使用寿命，提出了PCB的改进解决方案。