Multiple thermal path packaging for solid state light emitting apparatus and associated assembling methods

• US 7,625,103 B2
• Filed: 04/21/2006
• Issued: 12/01/2009
• Est. Priority Date: 04/21/2006
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Villard, Russell George
• Primary Examiner(s): Sawhney; Hargobind S
• Application Number:
  US11/408,767
• Publication Number:
  US 20070262337A1
• Time in Patent Office: 1,320 Days
• Field of Search: 362/227, 362/294, 362/310, 362/373, 362543-547, 362/800, 257/712, 257/714, 257/717, 257/720, 257/721, 257/723, 165/65, 165/66, 174/252, 174/255, 174/256, 174/261, 174/266, 361687-699
• US Class Current: 362/294
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21V 29/503 of light sources cooling arrangements structurally associated with gas-discharge or vapour-discharge lamps H01J61/52; cooling arrangements structurally associated with electric incandescent lamps H01K1/58; cooling arrangements structurally associated with light-emitting diodes H01L33/64
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 33/642 characterized by the shape

Abstract

A mounting substrate includes a peripheral portion and a central portion. Solid state light emitting elements are provided on the mounting substrate. A housing is configured to thermally couple to the peripheral portion of the mounting substrate, so as to provide a first thermal conduction path for at least some heat generated by the solid state light emitting elements. A thermal conduction member is configured to thermally couple the central portion of the mounting substrate to the housing, so as to provide a second thermal conduction path that is different from the first thermal conduction path, for at least some heat generated by the solid state light emitting elements. Related assembling methods are also described.

Claims

1. A light emitting apparatus comprising:

a mounting substrate that includes a peripheral portion and a central portion;

a plurality of solid state light emitting elements on the mounting substrate;

a housing that provides a first thermal conduction path for at least some heat generated by the solid state light emitting elements;

by being in contact with the peripheral portion of the mounting substrate

a first thermal conduction apparatus that provides a second thermal conduction path that is different than the first thermal conduction path to the housing for at least some heat generated by the solid state light emitting elements;

by being in contact with the central portion of the mounting substrate and

a second thermal conduction apparatus that provides a third thermal conduction path to the housing that is different than the first and second thermal conduction paths for at least some heat generated by the solid state light emitting elements by being in contact with an intermediate portion of the mounting substrate that is between the central portion and the peripheral portion.

2. A light emitting apparatus according to claim 1 wherein the housing provides the first thermal conduction path through the peripheral portion of the mounting substrate to the housing.

3. A light emitting apparatus according to claim 1 wherein the mounting substrate includes first and second opposing faces, wherein the solid state light emitting devices are on the first face and wherein the first thermal conduction apparatus provides the second thermal conduction path to the housing by being in contact with the central portion of the second face.

4. A light emitting apparatus according to claim 1 wherein the mounting substrate includes first and second opposing faces, wherein the solid state light emitting devices are on the first face, wherein the first thermal conduction apparatus provides the second thermal conduction path to the housing by being in contact with the central portion of the second face and wherein the second thermal conduction apparatus provides the third thermal conduction path to the housing by being in contact with the intermediate portion of the second face.

5. A light emitting apparatus according to claim 4 wherein the second thermal conduction apparatus is a ring-shaped member including a face that is in contact with the intermediate portion of the second face of the mounting substrate and including an aperture therein, and wherein the first thermal conduction apparatus extends through the aperture to the central portion of the second face of the mounting substrate.

6. A light emitting apparatus according to claim 1 wherein the housing comprises a cylinder and wherein the mounting substrate comprises a disk that is mounted coaxially within the cylinder.

7. A light emitting apparatus according to claim 1 wherein the first thermal conduction apparatus comprises at least one thermally conductive beam that extends between the central portion of the mounting substrate and the housing.

8. A light emitting apparatus according to claim 7 wherein the at least one thermally conductive beam is fixedly attached to both the mounting substrate and the housing.

9. A light emitting apparatus according to claim 7 wherein the at least one thermally conductive beam is fixedly attached to only one of the mounting substrate or the housing.

10. A light emitting apparatus according to claim 1 wherein the housing comprises a cylinder, wherein the mounting substrate comprises a disk, wherein the second thermal conduction apparatus comprises a ring-shaped member including a face that is in contact with a face of the mounting substrate at the intermediate portion and includes an aperture therein, and wherein the first thermal conduction apparatus comprises at least one thermally conductive beam that extends from the face of the mounting substrate at the central portion, through the aperture to the housing.

11. A light emitting apparatus according to claim 1 wherein the first thermal conduction apparatus comprises a thermally conductive fibrous pad that extends between the central portion of the mounting substrate and the housing.

12. A light emitting apparatus according to claim 11 wherein the thermally conductive fibrous pad comprises a copper scouring pad.

13. A light emitting apparatus according to claim 1 wherein the plurality of solid state light emitting elements comprise a plurality of light emitting diodes.

14. A light emitting apparatus according to claim 1 wherein the housing comprises a metal cylinder.

15. A light emitting apparatus according to claim 1 wherein:

the housing provides the first thermal conduction path by being in contact with the peripheral portion of the mounting substrate at a first portion of the housing;

the first thermal conduction apparatus provides the second thermal conduction path by being in contact with the central portion of the mounting substrate and a second portion of the housing that is spaced apart from the first portion; and

the second thermal conduction apparatus provides the third thermal conduction path by being in contact with the intermediate portion of the mounting substrate and a third portion of the housing, wherein the third portion of the housing is located between the first and second portions of the housing.

16. A light emitting apparatus comprising:

a cylindrical housing;

a disk-shaped mounting substrate that includes first and second opposing faces, each face including a peripheral portion and a central portion, and being mounted coaxially in the cylindrical housing;

a plurality of solid state light emitting elements on the peripheral and central portions of the first face of the mounting substrate, wherein the cylindrical housing provides a first thermal conduction path for at least some heat generated by the solid state light emitting elements;

by being in contact with the peripheral portion of the mounting substrate;

a first thermal conduction apparatus comprising at least one thermally conductive member that extends from the central portion of the second face of the mounting substrate to the cylindrical housing remote from the second face, the first thermal conduction apparatus provides a second thermal conduction path to the cylindrical housing that is different than the first thermal conduction path for at least some heat generated by the solid state light emitting elements by being in contact with the central portion of the mounting substrate; and

a second thermal conduction apparatus comprising a ring-shaped thermally conductive member having a face that is in contact with an intermediate portion of the second face of the mounting substrate that is between the central portion and the peripheral portion of the second face of the mounting substrate and including an aperture therein, the second thermal conduction apparatus providing a third thermal conduction path to the housing that is different than the first and second thermal conduction paths for at least some heat generated by the solid state light emitting elements by being in contact with the intermediate portion of the mounting substrate, wherein the at least one thermally conductive member extends from the central portion of the second face of the mounting substrate, through the aperture and to the cylindrical housing remote from the second face.

17. A light emitting apparatus according to claim 16 wherein the at least one thermally conductive member is fixedly attached to the central portion of the second face of the mounting substrate and is fixedly attached to the cylindrical housing remote from the second face.

18. A light emitting apparatus according to claim 16 wherein the plurality of solid state light emitting elements comprise a plurality of light emitting diodes.

19. A light emitting apparatus according to claim 16 wherein:

the cylindrical housing provides the first thermal conduction path by being in contact with the peripheral portion of the mounting substrate at a first portion of the cylindrical housing;

the first thermal conduction apparatus provides the second thermal conduction path by being in contact with the central portion of the mounting substrate and a second portion of the cylindrical housing that is spaced apart from the first portion; and

the second thermal conduction apparatus provides the third thermal conduction path by being in contact with; and

the intermediate portion of the mounting substrate to a third portion of the cylindrical housing, wherein the third portion of the cylindrical housing is located between the first and second portions of the cylindrical housing.

20. A light emitting apparatus according to claim 16 wherein the at least one thermally conductive member comprises a thermally conductive fibrous pad that extends from the central portion of the second face of the mounting substrate to the cylindrical housing remote from the second face.

21. A light emitting apparatus according to claim 20 wherein the thermally conductive fibrous pad comprises a copper scouring pad.

22. A method of assembling a light emitting apparatus that includes a housing that has a support lip and a mounting substrate that has a peripheral portion and a central portion, and a plurality of solid state light emitting elements on the mounting substrate, the method comprising:

inserting the mounting substrate into the housing and onto the support lip; and

mounting at least one thermally conductive fibrous pad in the housing to extend from the central portion of the mounting substrate to the housing remote from the mounting substrate.

23. A method according to claim 22 wherein the plurality of solid state light emitting elements comprise a plurality of light emitting diodes.

24. A light emitting apparatus according to claim 22 wherein the thermally conductive fibrous pad comprises a copper scouring pad.

25. A light emitting apparatus comprising:

a mounting substrate that includes a peripheral portion and a central portion;

a plurality of solid state light emitting elements on the mounting substrate, the mounting substrate configured to provide a first thermal conduction path from the central portion to the peripheral portion for at least some heat generated by the plurality of solid state light emitting elements;

a first thermal conduction apparatus that provides a second thermal conduction path that is different than the first thermal conduction path from the central portion therethrough for at least some heat generated by the plurality of solid state light emitting elements by being in contact with the central portion of the mounting substrate; and

a second thermal conduction apparatus that provides a third thermal conduction path that is different than the first and second thermal conduction paths for at least some heat generated by the plurality of light emitting elements by being in contact with an intermediate portion of the mounting substrate that is between the central portion and the peripheral portion,

wherein the first thermal conduction apparatus comprises a thermally conductive fibrous pad that is in contact with the central portion of the mounting substrate.

26. A light emitting apparatus according to claim 25 wherein the mounting substrate includes first and second opposing faces, wherein the solid state light emitting devices are on the first face and wherein the first thermal conduction apparatus is in contact with the central portion of the second face.

27. A light emitting apparatus according to claim 25 wherein the mounting substrate includes first and second opposing faces, wherein the solid state light emitting devices are on the first face, wherein the second thermal conduction apparatus is a ring-shaped member including a face that is in contact with the intermediate portion of the second face of the mounting substrate and including an aperture therein, and wherein the first thermal conduction apparatus extends through the aperture to the central portion of the second face of the mounting substrate.

28. A light emitting apparatus according to claim 25 wherein the plurality of solid state light emitting elements comprise a plurality of light emitting diodes.

29. A light emitting apparatus according to claim 25 wherein the thermally conductive fibrous pad comprises a copper scouring pad.