Finite Element Analysis on Structural Stress of 8x8 Infrared Focal Plane Array integrating with microlens arrays

Based on finite element analysis, the structural stress of 8x8 InSb Infrared Focal Plane Array integrating with microlens arrays dependent on indium bump sizes is systemically researched. Simulation results show that as the diameters of indium bump increase from 16 mu m to 38 mu m in step of 2 mu m, the maximum stress existing in InSb chip first reduces, then increases, and reaches minimum with indium bump diameter 32 mu m. Yet the maximum stress in the indium bump array is almost unchangeable and keeps at 16.5MPa. The maximum stress in Si readout integrated circuit almost half stress in InSb chip. Besides, the stress appearing on those regions situating just on microlens array is much smaller than its surrounding regions, and the stress distribution is uniform at contacting areas between InSb chip and indium bump.