Infrared camera architecture systems and methods

• US 8,743,207 B2
• Filed: 07/27/2010
• Issued: 06/03/2014
• Est. Priority Date: 07/27/2010
• Status: Active Grant

• Current Assignee: Teledyne FLIR LLC (Teledyne Technologies Incorporated)
• Original Assignee: FLIR Systems, Inc. (Teledyne Technologies Incorporated)
• Inventors: Boulanger, Pierre, Tremblay, Marcel, Goodland, Jim, Sharp, Barbara, Mirbod, Farhad, Hoelter, Theodore R.
• Primary Examiner(s): Perungavoor, Sath V
• Assistant Examiner(s): Le, Peter D
• Application Number:
  US12/844,124
• Publication Number:
  US 20120026337A1
• Time in Patent Office: 1,407 Days
• Field of Search: 348/164
• US Class Current: 348/164
• CPC Class Codes: G01J 1/0204 Compact construction
• CPC Class Codes: G01J 1/44 Electric circuits for command of an exposure part G03B7/02
• CPC Class Codes: G01J 2005/0077 Imaging
• CPC Class Codes: G01J 2005/204 prepared by semiconductor processing, e.g. VLSI
• CPC Class Codes: G01J 5/02 Constructional details
• CPC Class Codes: G01J 5/0215 Compact construction
• CPC Class Codes: G01J 5/023 Particular leg structure or construction or shape; Nanotubes
• CPC Class Codes: G01J 5/046 Materials; Selection of thermal materials
• CPC Class Codes: G01J 5/10 using electric radiation detectors
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: H01L 22/14 for electrical parameters, e.g. resistance, deep-levels, CV, diffusions by electrical means
• CPC Class Codes: H01L 22/32 Additional lead-in metallisation on a device or substrate, e.g. additional pads or pad portions, lines in the scribe line, sacrificed conductors arrangements for conducting electric current to or from the solid state body in operation H01L23/48
• CPC Class Codes: H01L 27/146 Imager structures
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/1462 Coatings
• CPC Class Codes: H01L 27/14632 Wafer-level processed structures
• CPC Class Codes: H01L 27/14636 Interconnect structures
• CPC Class Codes: H01L 27/14669 Infrared imagers
• CPC Class Codes: H01L 27/14687 Wafer level processing
• CPC Class Codes: H01L 27/14698 Post-treatment for the devices, e.g. annealing, impurity-gettering, shor-circuit elimination, recrystallisation
• CPC Class Codes: H04N 23/52 : Elements optimising image sensor operation, e.g. for electromagnetic interference [EMI] protection or temperature control by heat transfer or cooling elements
• CPC Class Codes: H04N 5/33 : Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20
• CPC Class Codes: H10N 15/10 : Thermoelectric devices using thermal change of the dielectric constant, e.g. working above and below the Curie point
• CPC Class Codes: Y10T 29/49826 : Assembling or joining

Abstract

An infrared camera architecture includes, for an embodiment, an infrared detector, a substrate, a plurality of electrical components coupled to the substrate, and a pedestal made of a thermally conductive material and having a leg coupled to the substrate. The infrared detector is supported by and thermally coupled to the pedestal, with the pedestal thermally isolating the infrared detector from the plurality of electrical components.

Claims

1. An infrared camera, comprising:

an infrared detector comprising a focal plane array adapted to capture infrared images;

a substrate;

a plurality of electrical components coupled to the substrate;

a pedestal made of a thermally conductive material and coupled to the substrate, wherein the infrared detector is supported by and thermally coupled to the pedestal, the pedestal thermally isolating the infrared detector from the plurality of electrical components and providing thermal uniformity across the focal plane array of the infrared detector; and

a core housing coupled to and in contact with the substrate and the pedestal, wherein the core housing, the infrared detector, the substrate, the pedestal, and the plurality of electrical components form an infrared camera core.

2. The infrared camera of claim 1, wherein the pedestal is made of copper, has three or more legs coupled to the substrate, and provides heat dissipation and heat spreading to maintain a substantially thermally uniform surface for coupling to the infrared detector, and wherein the infrared camera comprises:

an adhesive disposed between the infrared detector and the pedestal to couple the infrared detector to the pedestal and to reduce thermal expansion coefficient mismatch between the pedestal and the infrared detector.

3. The infrared camera of claim 1, wherein the infrared detector comprises a wafer level package vacuum package assembly electrically coupled to the substrate and/or to the plurality of electrical components, wherein the core housing comprises a hardened liquid epoxy configured to encapsulate the plurality of electrical components and at least partially the infrared detector, the substrate, and/or the pedestal, and wherein the infrared camera core comprises an uncooled infrared camera core.

4. The infrared camera of claim 1, wherein the plurality of electrical components comprises:

a die stack having a logic die and a memory die adapted to support the infrared detector; and

a power management device adapted to receive a power supply voltage external to the infrared camera core and provide all required voltages for the infrared camera core;

wherein the infrared camera core receives the power supply voltage and provides infrared image data.

5. The infrared camera of claim 4, wherein the die stack and the power management device are wire bonded to the substrate, wherein the substrate comprises a bismaleimide triazine substrate having a ball grid array, and wherein the pedestal is made of copper and comprises a black oxide and/or a nickel coated finish.

6. The infrared camera of claim 5, wherein the logic die is coupled to the substrate using flip chip technology.

7. The infrared camera of claim 1, comprising:

a camera housing;

a lens within the camera housing; and

the infrared camera core within the camera housing;

wherein the pedestal comprises an alignment feature, formed in, on, or of a top surface of the pedestal, corresponding to an alignment feature within the camera housing to provide optical alignment of the infrared detector with the lens.

8. The infrared camera of claim 7, wherein the alignment features provide X, Y, and Z alignment positioning.

9. The infrared camera of claim 1, comprising:

a camera housing;

a lens within the camera housing; and

the infrared camera core within the camera housing;

wherein the pedestal is configured to provide a first thermal path between the infrared detector, the camera housing, and the lens.

10. The infrared camera of claim 9, comprising a rear cover coupled to the camera housing and having an electrical interface connector, wherein the substrate is configured to provide a second thermal path from the plurality of electrical components to the rear cover, wherein the rear cover is configured to thermally couple the second thermal path to the camera housing.

11. An infrared camera, comprising:

an infrared detector comprising a focal plane array adapted to capture infrared images;

a pedestal thermally coupled to the infrared detector and providing thermal uniformity across the focal plane array of the infrared detector, the pedestal having an infrared detector alignment feature formed in, on, or of a top surface of the pedestal;

a substrate coupled to the pedestal;

a die stack coupled to the substrate, wherein the pedestal is configured to thermally protect the infrared detector from the die stack;

an infrared camera core housing configured to at least partially house the infrared detector, the pedestal, the substrate, and the die stack to form an infrared camera core;

a camera housing having an optical alignment feature within the camera housing and at least partially enclosing the infrared camera core; and

a lens within the camera housing;

wherein the optical alignment feature and the infrared detector alignment feature are coupled to provide optical alignment of the infrared detector with the lens.

12. The infrared camera of claim 11, wherein the pedestal is made of a thermally conductive material and is coupled to the infrared detector with an adhesive to reduce thermal expansion coefficient mismatch between the pedestal and the infrared detector, the pedestal adapted to provide heat dissipation and heat spreading to maintain a substantially thermally uniform surface for coupling to the infrared detector, and wherein the infrared detector is electrically coupled to the die stack and/or the substrate.

13. The infrared camera of claim 11, wherein the infrared detector comprises a wafer level package vacuum package assembly, wherein the infrared camera core housing comprises a hardened liquid epoxy that encapsulates the die stack and leaves unobstructed the infrared detector alignment feature and an opening through which the infrared detector receives infrared energy via the lens, and wherein the infrared camera core comprises an uncooled infrared camera core.

14. The infrared camera of claim 11, comprising a power management circuit coupled to the substrate, wherein the pedestal is configured to thermally protect the infrared detector from the power management circuit, the power management circuit adapted to receive a power supply voltage and provide one or more voltages for the infrared camera core, and wherein the infrared camera core provides infrared image data.

15. The infrared camera of claim 11, wherein the pedestal is configured to provide a first thermal path between the infrared detector, the camera housing, and the lens, and wherein the substrate and the camera housing are configured to form a second thermal path between the die stack and the camera housing.

16. The infrared camera of claim 15, wherein the camera housing has a rear cover thermally coupled to the substrate to form the second thermal path, the rear cover having an electrical interface connector to provide infrared image data based on the captured infrared images and receive a power supply voltage.

17. A method of assembling an infrared camera, the method comprising:

mounting a die stack to a substrate;

securing a pedestal to the substrate and above the die stack, the pedestal made of a thermally conductive material;

adhering an infrared detector to the pedestal, wherein the infrared detector comprises a focal plane array adapted to capture infrared images and is supported by and thermally coupled to the pedestal, and wherein the pedestal is configured to thermally isolate the infrared detector from the die stack and provide thermal uniformity across the focal plane array of the infrared detector; and

encapsulating at least partially the substrate and the die stack and/or further encapsulating at least partially the pedestal and the infrared detector as part of or within a core housing to form an infrared camera core.

18. The method of claim 17, comprising:

installing an optics housing having at least one lens into an infrared camera housing;

aligning the infrared camera core within the infrared camera housing by matching a first alignment feature formed in, on, or of a top surface of the pedestal with a second alignment feature within the infrared camera housing to position the infrared detector relative to the at least one lens; and

securing the infrared camera core within the infrared camera housing.

19. The method of claim 17, wherein the adhering reduces thermal expansion coefficient mismatch between the pedestal and the infrared detector, the pedestal adapted to provide heat dissipation and heat spreading to maintain a substantially thermally uniform surface for coupling to the infrared detector, and wherein the infrared camera core comprises an uncooled infrared camera core.

20. The method of claim 18,

comprising electrically coupling the infrared detector to the substrate, and wherein the pedestal is configured to provide a first thermal path between the infrared detector, the infrared camera housing, and the at least one lens, and wherein the substrate and the camera housing are configured to form a second thermal path between the die stack and the camera housing.