Abstract: A focal plane array uses non-contact electrical interconnects instead of indium bumps. The interconnect bump comprises one or more vacuum microelectronics devices. The non-contact interconnect provides no themally conductive path between the detector and readout. For thermal detectors, the detector is not thermally connected to the readout and thus undergoes larger temperature changes in response to infrared radiation. For cryogenically cooled detectors, the detector and readout each have separate heat sinks with separate temperature controls. The readout may thus be operated at a higher temperature than the detector. The non-contact interconnect eliminates heat leakage from the readout to the detector enabling a thermal gradient to be maintained simultaneously with a net savings in refrigerator power. The non-contact interconnect also allows for differences in thermal expansion between the detector and the readout and thus increases the reliability of the focal plane array.

Abstract: A focal plane array having an interconnect bump that has high thermal resistivity, and which may be used to interconnect the detector and readout of the array. The detector and readout each have separate heat sinks with separate temperature controls. The readout may thus be operated at a higher temperature than the detector. A high thermal resistance interconnect bump is employed to limit heat leakage from the readout to the detector to an acceptable level, and to enable a thermal gradient to be maintained simultaneously with a net savings in refrigerator power. The heat sink for the detector is made in such a way as to not obscure the active area of the detector, that is, it is annular in shape so as to surround the active area of the detector. The interconnect bump comprises a thermally insulating pedestal comprising a material such as polyimide, for example, with an over-the-edge metallization employed as an electrical contact.