目的 为了评估就地化保护装置跌落冲击载荷下的失效情况。方法 基于显式动力学理论，采用有限元法对就地化保护装置进行跌落冲击的建模仿真。分析PCB板变形与焊点失效之间的关系，探讨元件封装方式对产品抗跌落冲击性能的影响，提出以Von Mises准则得到的焊点最大应力联合跌落寿命模型，进行元件封装可靠性评估的分析方法。针对元件不同封装方式的装置进行跌落验证试验。结果 就地化保护装置跌落冲击仿真结果与试验结果基本吻合。结论 验证了评估元件封装失效分析方法的准确性，为推断产品可靠性提供了理论支撑。

The paper aims to explore the reliability of in-situ protective devices under drop impact load. Based on explicit dynamics theory, the finite element method (FEM) was used to simulate the drop impact of in-situ protective devices. The relationship between PCB plate deformation and solder joint failure was analyzed, and the influence of component encapsulation on drop impact resistance of products was discussed. An analytical method for evaluating component encapsulation failure was proposed based on maximum stress on Von Mises and life prediction model. Drop tests were carried out for different encapsulation modes of components. The results show that the simulation results of drop impact of in-situ protective devices were basically consistent with the experimental data. The accuracy of failure analysis method for component encapsulation is verified, providing theoretical support for inferring product reliability.