Overmolded LED light assembly and method of manufacture

• US 8,827,508 B2
• Filed: 10/22/2010
• Issued: 09/09/2014
• Est. Priority Date: 10/22/2009
• Status: Active Grant

• Current Assignee: Thermal Solution Resources, LLC
• Original Assignee: Thermal Solution Resources, LLC
• Inventors: Sagal, E. Mikhail
• Primary Examiner(s): Guharay, Karabi
• Application Number:
  US12/910,340
• Publication Number:
  US 20110095690A1
• Time in Patent Office: 1,418 Days
• Field of Search: 313/46, 362/249.02, 362/373, 362/294
• US Class Current: 362/373
• CPC Class Codes: B29C 45/0013 using fillers dispersed in the moulding material, e.g. metal particles
• CPC Class Codes: B29C 45/14 incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles B29C45/1671 takes precedence
• CPC Class Codes: B29K 2995/0013 Conductive
• CPC Class Codes: F21K 9/233 specially adapted for generating a spot light distribution, e.g. for substitution of reflector lamps
• CPC Class Codes: F21V 17/164 the parts being subjected to bending, e.g. snap joints
• CPC Class Codes: F21V 19/005 by permanent fixing means, e.g. gluing, riveting or embedding in a potting compound
• CPC Class Codes: F21V 29/507 of means for protecting lighting devices from damage, e.g. housings
• CPC Class Codes: F21V 29/773 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 29/87 Organic material, e.g. filled polymer composites; Thermo-conductive additives or coatings therefor
• CPC Class Codes: F21V 29/89 Metals
• CPC Class Codes: F21V 31/04 Provision of filling media
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

In one aspect, an LED lighting apparatus includes an electronic circuit board having a peripheral portion and a central portion that is radially inward of said peripheral portion, said electronic circuit board having an exterior side for optically interfacing with ambient environment during operation and an interior side opposite the exterior side. At least one LED is mounted on the exterior side of the electronic circuit board central portion and a thermally conductive housing encloses said electronic circuit board, said thermally conductive housing formed of a moldable thermally conductive material. The thermally conductive housing defines a first cavity adjacent the central portion of the electronic circuit board exterior side and a second cavity adjacent the central portion of the electronic circuit board interior side, wherein a portion of said thermally conductive housing being overmolded onto said peripheral portion. In a further aspect, a method of manufacturing an LED lighting apparatus is provided.

Claims

1. An LED lighting apparatus, comprising:

an electronic circuit board having a peripheral portion and a central portion that is radially inward of said peripheral portion, said electronic circuit board having an exterior side for optically interfacing with ambient environment during operation and an interior side opposite the exterior side;

at least one LED mounted on the exterior side of the electronic circuit board central portion;

a thermally conductive housing enclosing said electronic circuit board, said thermally conductive housing formed of a moldable thermally conductive material;

said thermally conductive housing together with the exterior side of the electronic circuit board cooperating to define a first cavity, said first cavity proximate adjacent the central portion of the electronic circuit board exterior side; and

said thermally conductive housing together with the interior side of the electronic circuit board cooperating to define a second cavity, said second cavity proximate the central portion of the electronic circuit board interior side, a portion of said thermally conductive housing being overmolded onto said peripheral portion.

2. The LED lighting apparatus of claim 1, wherein said moldable thermally conductive material is a thermally conductive plastic.

3. The LED lighting apparatus of claim 1, further comprising:

an LED driver received within said second cavity.

4. The LED lighting apparatus of claim 3, further comprising:

an electrical connector on said electronic circuit board for mating with a complimentary electrical connector on said LED driver to electrically couple said LED driver to said at least one LED.

5. The LED lighting apparatus of claim 3, wherein said LED driver includes an LED driver housing enclosing an LED driver circuit board, said LED driver housing formed of a thermally conductive, electrically insulating plastic.

6. The LED lighting apparatus of claim 1, further comprising:

said first cavity defining an opening; and

a lens affixed about said opening.

7. The LED lighting apparatus of claim 6, wherein said lens is selected from a transparent plate, an optical diffuser, and an optical beam shaper.

8. The LED lighting apparatus of claim 6, wherein said lens has a coating on the surface comprised of quantum dots which allow the lens to convert white LED light to warm LED light.

9. The LED lighting apparatus of claim 1, wherein said electronic circuit board is a printed circuit board.

10. The LED lighting apparatus of claim 9, wherein said printed circuit board is a metal core printed circuit board.

11. The LED lighting apparatus of claim 10, further comprising:

a thermal slug mounted on the exterior side of said electronic circuit board and adjacent each of said at least one LED and in thermal communication with said metal core printed circuit board.

12. The LED lighting apparatus of claim 9, wherein said printed circuit board is a non-metallic printed circuit board.

13. The LED lighting apparatus of claim 12, further comprising:

a heat spreader plate adjacent the interior side of the electronic circuit board, said heat spreader plate in thermal communication with said at least one LED, wherein a portion of said thermally conductive housing is overmolded onto a peripheral portion of said heat spreader plate.

14. The LED lighting apparatus of claim 13, further comprising:

a thermal slug mounted on the exterior side of said electronic circuit board and adjacent each of said at least one LED and in thermal communication with said heat spreader plate.

15. The LED lighting apparatus of claim 1, wherein the moldable thermally conductive material comprises a polymer matrix material and a thermally conductive filler.

16. The LED lighting apparatus of claim 15, wherein the thermally conductive filler is selected from the group consisting of natural and synthetic graphite, carbon fiber, carbon black, boron nitride, aluminum nitride, silicon nitride, silicon oxide, metal oxides, and combinations thereof.

17. The LED lighting apparatus of claim 15, wherein the moldable thermally conductive material is electrically conductive.

18. The LED lighting apparatus of claim 15, wherein said moldable thermally conductive material is electrically insulating.

19. A method of manufacture, comprising:

providing an electronic circuit board having a peripheral portion and a central portion that is radially inward of said peripheral portion, said electronic circuit board having an exterior side for optically interfacing with ambient environment during operation and an interior side opposite the exterior side;

mounting at least one LED mounted on said exterior side of the electronic circuit board central portion; and

overmolding said electronic circuit board peripheral portion with a moldable thermally conductive material to form an overmolded thermally conductive housing enclosing said electronic circuit board, said thermally conductive housing together with the exterior side of the circuit board cooperating to define a first cavity, the first cavity proximate the central portion of the electronic circuit board exterior side and said thermally conductive housing together with the interior side of the electronic circuit board cooperating to define a second cavity, the second cavity proximate the central portion of the electronic circuit board interior side.

20. The method of manufacture of claim 19, wherein said moldable thermally conductive material comprises a polymer matrix material and a thermally conductive filler.

21. The method of manufacture of claim 20, wherein said moldable thermally conductive material is electrically conductive.

22. The method of manufacture of claim 20, wherein said moldable thermally conductive material is electrically insulative.

23. The method of manufacture of claim 19, wherein said overmolding is an injection overmolding.

24. The method of claim 19, wherein said step of mounting said at least one LED on said exterior side of the electronic circuit board central portion is performed prior to said step of overmolding said electronic circuit board peripheral portion with a moldable thermally conductive material.

25. The method of claim 19, further comprising:

attaching an optically transparent cover over said circuit board exterior side using a fastener integrally formed on said overmolded thermally conductive housing.

26. The method of claim 19, further comprising:

electrically coupling an LED driver electronics module to said electronic circuit board.

27. The method of claim 26, wherein the LED driver electronics module is attached to the overmolded thermally conductive housing a fastener integrally formed on said overmolded thermally conductive housing.