"Implementation Of A Hybridization Station For Mating Grumman Z-Plane Modules With HgCdTe Arrays"

Abstract

This paper discusses the hybridization,electrical interconnection via indium bump bonds, of Rockwell designed and fabricated infrared detector arrays onto three dimensional Grumman (Z-Plane) ceramic signal processing modules. The hybridization of detector arrays to the Z-Plane module provides the basic building block for large two dimensional focal plane arrays. This unique Z-Plane module provides on-focal plane data processing which decreases the requirement for interconnect wiring between the focal plane and data processing electronics. This effort implements a modified bonder mating station for use in hybridizing Grumman ceramic multi-layered Z-Plane modules and Rockwell HgCdTe photovoltaic detector arrays. The work involves the hybridization of large aspect ratio detector arrays (16:1). Two detector arrays are mounted end to end on a Z-Plane module for a total length of over one inch. The mating station features a visible viewing system which displays both the detector array and module indium bumps prior to mating. The detector array has electro-plated indium bumps with a typical height of 10-12 microns and the Z-Plane module has vacuum deposited indium pads typically 3 microns high. Hybrid mating tolerances on the order of two tenths of a mil accuracy are routinely held. The hybrid mating station will be reviewed through initial modification, engineering evaluation, semi-manual operation, optimization of mating parameters, resultant bond pull strength and effect on photodiodes. Current yield for this mating system will also be presented. The system will be further refined to increase ease of operation and throughput with the addition of software and microprocessor control. The commitment to achieving good mechanical and electrical indium bonds in this Z-Plane technology has resulted in successful hybrids using both short wave (SWIR) and medium wave (MWIR) infrared HgCdTe detector arrays.