Method for determining critical pressure in assembling hybrid MCT focal plane arrays

A simple method is proposed for determining the critical pressure that does not destroy CdxHg1−xTe diodes in hybrid assembling. The method allows obtaining a set of data that reliably define the critical parameter (the value of force) of the flip-chip hybrid FPA process. The method was tested on CdxHg1−xTe samples (x = 0.21). It is found that the abrupt change in the electrophysical properties of the material occurs when the diameter of indium bumps increases 2 times and more during compression at a pressure of about 3 kg/mm2. The obtained gage load/bump deformation dependences show that this pressure corresponds to the beginning of the region of indium strengthening on the deformation curve.