Structural Stress Analysis of 16×16 InSb Infrared Focal Plane Array with Underfill
To reduce the fracture probability of InSb infrared detector in thermal shock from room temperature to 77K, for 16×16 mesa structure InSb infrared focal plane array detector with underfill, here ANSYS, is employed to research the impacts from both indium bump diameters and heights on both Von Mises stress and its distribution. Simulation results show that when the diameters of indium bump increases from 20µm to 36µm in step of 4µm, the maximal Von Mises stress in the InSb chip increases slowly. Besides, when the height of indium bump increases from 8μm to 24μm in step of 8μm, the maximal Von Mises stress in the InSb chip reduces from 1200MPa to 1030MPa. Von Mises stress of Si readout integrated circuits is also much smaller than that of InSb chip.
Dongye Sun, Wen-Pei Sung and Ran Chen
Q. Yu et al., "Structural Stress Analysis of 16×16 InSb Infrared Focal Plane Array with Underfill", Applied Mechanics and Materials, Vols. 121-126, pp. 4320-4324, 2012