A technology for assembling large-format infrared photodetector modules on indium microposts

摘要

The initial plane-parallel position of a photodetector array (PDA) and a silicon multiplexer (MUX) is brought about when the tops of the indium microposts are in contact under the action of only the force of gravity on the PDA. We orient the crystals (along xy) in visible light, and we use offset reference marks on the PDAs. We bring chains of laser microholes in the polyimide of the offset reference marks into coincidence with the reference marks on the MUX. We take into account the initial errors of all the axial lines; the alignment error reaches +/- 0.4 mu m (along xy). At all stages of the assembly, the MUX is connected, and we observe the touching and the welding of the microposts. To avoid warping the planar transistors (along z), we use stops of suitable height, placed along the perimeter of the PDA.