液氮冲击中InSb 焦平面探测器的局部分层、局部碎裂制约着其成品率的提高。为分析液氮冲击中发生在InSb 焦平面探测器中的潜在失效模式，我们借助C. H. Hsueh 提出的适用于弹性多层体系热应力计算理论，结合InSb 焦平面探测器的典型结构，忽略铟柱阵列的影响，得到了InSb 焦平面探测器中心区域热应变和热应力沿厚度方向的分布。依据热应变和热应力分布，我们认为液氮冲击中InSb 芯片和底充胶均处于拉应力状态，硅读出电路上边2/3 部分处于压应力状态，下边1/3 部分处于拉应力状态。整个探测器四角往上翘曲，中心区域往下凸起。这些计算结果为后续探测器组件封装中平衡复合物结构的设计提供了理论参考。

Local delamination and local fractures appearing in InSb focal plane arrays detector (InSb IRFPAs) under liquid nitrogen shock tests restrict its final yield. We analyze the major failure modes appearing in InSb IRFPAs under liquid nitrogen shock tests using the typical structure of InSb IRFPAs, employing the theory proposed by C. H. Hsueh for calculating the thermal stress in the elastic multi-layer system, and neglecting the effect from indium bump arrays. As a result, we obtain the thermal strain and thermal stress distributions along the normal direction of InSb IRFPAs in its central region. The following conclusions can be drawn according to the thermal strain and thermal stress distributions: in the liquid nitrogen shock tests, both the InSb chip and the under fill are in the tensile stress state; for the silicon readout integrated circuits (ROIC), 2/3^rd of its upper part is in the compressive stress state, and 1/3^rd of its lower part is in the tensile stress state. The four corners of InSb IRFPAs bend upwards, and its central region is convex downwards. These calculation results provide a theoretical reference for designing a balanced composite structure in the assembly of IRFPAs.