Infrared detector

Abstract

An infrared detector wherein an infrared detecting device can be cooled efficiently without increasing thermal stresses generated in the device body owing to cooling during the operation of the detector, and intrusion of ambient light can be prevented. A container for the infrared detecting device, which includes a bottom plate having a projection formed in the center thereof, is provided on an inner end portion of an inner cylinder constituting a dewar, and the infrared detecting device is placed on and secured to the projection of the bottom plate. The container bottom plate is made of an Invar, while the end portion of the inner cylinder is made of a Kovar or an Invar.

What is claimed is: 
     
       1. An infrared detector including: a dewar having an outer cylinder with a window for transmitting incident infrared radiation, and an inner cylinder united with said outer cylinder so as to form a space for inserting cooling means, an   an infrared detecting device accommodated in said dewar and driven while being cooled to a cryogenic temperature by said cooling means from the outside of said dewar,   wherein the improvement comprises a container for accommodating said infrared detecting device, said container including a bottom plate having a projection projecting inwardly of said container from an inner surface thereof, so that said infrared detecting device is secured to said projection of said bottom plate, said bottom plate being secured to an end portion of said inner cylinder which is disposed in said dewar, thereby disposing said container in said dewar.   
     
     
       2. An infrared detector according to claim 1, wherein said bottom plate of said container for said infrared detecting device is made of .[.an Invar.]. .Iadd.a nickel-iron alloy.Iaddend.. 
     
     
       3. An infrared detector according to claim 1, wherein said container for said infrared detecting device comprises said bottom plate, a frame secured to said bottom plate to constitute a part of said container, and a cold shield secured to said frame to constitute a part of said container, and an upper surface of said infrared detecting device is secured to said frame. 
     
     
       4. An infrared detector according to claim 1, 2, or 3, wherein said infrared detecting device comprises a semiconductor substrate having a first major surface and a second major surface. 
     
     
       5. An infrared detector according to claim 3, wherein said infrared detecting device comprises a semiconductor substrate having a first major surface and a second major surface, said first major surface being connected to said frame through metallic conductors, said frame being provided with terminals, which are connected through metallic conductors to dewar internal conductors attached to a side surface of said inner cylinder inside said dewar, and said dewar internal conductors being connected through metallic conductors to external terminals provided on said outer cylinder of said dewar. 
     
     
       6. An infrared detector according to claim 1, wherein said end portion of said inner cylinder of said dewar is made of .[.Kovar.]. .Iadd.a nickel-cobalt-iron alloy.Iaddend.. 
     
     
       7. An infrared detector according to claim 3, wherein said infrared detecting device comprises a semiconductor substrate having a first major surface and a second major surface, said first major surface being secured to said projection of said bottom plate, and said second major surface being bonded at a peripheral edge thereof to said frame. 
     
     
       8. An infrared detector according to claim 2, wherein said .[.Invar.]. .Iadd.nickel-iron alloy .Iaddend.contains 36% Ni and 64% Fe. 
     
     
       9. An infrared detector according to claim 6, wherein said .[.Kovar.]. .Iadd.nickel-cobalt-iron alloy .Iaddend.contains 29% Ni, 17% Co, and 54% Fe. 
     
     
       10. An infrared detector including; a dewar having an outer cylinder with a window for transmitting incident infrared radiation, and an inner cylinder united with said outer cylinder so as to form a space for inserting cooling means, and   an infrared detecting device accommodated in said dewar and driven while being cooled to a cryogenic temperature by said cooling means from the outside of said dewar,   characterized in that said infrared detecting device is a silicon infrared detecting device, and an end portion of said inner cylinder which is disposed inside said dewar is made of .[.a Kovar or an Invar.]. .Iadd.one of a nickel-iron alloy and a nickel-cobalt-iron alloy .Iaddend.said silicon infrared detecting device being accommodated in a container, said container including a bottom plate made of a .[.Invar.]. .Iadd.nickel-iron alloy .Iaddend.and having a projection projecting inwardly of said container from an inner surface thereof, so that said silicon infrared detecting device is secured to said projection of said bottom plate, said bottom plate being secured to said end portion of said inner cylinder of said dewar, thereby disposing said container in said dewar.