Heat spreader for display panel

• US 7,666,270 B1
• Filed: 07/07/2005
• Issued: 02/23/2010
• Est. Priority Date: 10/14/2003
• Status: Expired due to Term

• Current Assignee: NeoGraf Solutions, LLC
• Original Assignee: Graftech International Holdings Inc (Graftech International Limited)
• Inventors: Smalc, Martin David, Clovesko, Timothy, Norley, Julian, Capp, Joseph Paul
• Primary Examiner(s): Tucker; Philip C
• Assistant Examiner(s): Chan; Sing P
• Application Number:
  US11/176,959
• Time in Patent Office: 1,692 Days
• Field of Search: 156/247, 156/249, 156/289, 428/40.1, 428/141, 428/323, 428/408, 428/143, 313/40, 313/45, 313/46, 313/493, 313/581, 313/582, 313/587, 313/634
• US Class Current: 156/249
• CPC Class Codes: B32B 43/006 Delaminating
• CPC Class Codes: B32B 5/16 characterised by features of a layer formed of particles, e.g. chips, powder or granules layer formed of natural mineral particles B32B19/00; layer being formed of wood fibres, chips or particles B32B21/02
• CPC Class Codes: B32B 9/00 Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
• CPC Class Codes: H01J 2217/492 Details
• CPC Class Codes: H05K 7/20963 Heat transfer by conduction from internal heat source to heat radiating structure H05K7/20972 takes precedence

Abstract

The invention presented is a method for applying heat spreaders to a plurality of display panels, including (a) providing a plurality of heat spreader composites, each of which comprises a heat spreader material having an adhesive thereon and a release material positioned such that the adhesive is sandwiched between the heat spreader material and the release material; (b) removing the release material from a plurality of the composites; and (c) applying at least one of the composites to each of the plurality of display panels each such that the adhesive adheres the heat spreader material to the display panel.

Claims

1. A method for cooling a collection of light-emitting heat sources in a liquid crystal display panel by applying a heat spreader thereto, the method comprising (a) providing an anisotropic heat spreader composite having two major surfaces and a thickness between the major surfaces, which comprises a heat spreader material comprising at least one sheet of compressed particles of exfoliated graphite, each heat spreader composite having an adhesive thereon and a release material positioned such that the adhesive is sandwiched between the heat spreader material and the release material, wherein the adhesive achieves a minimum lap shear adhesion strength of at least about 125 grams per square centimeter;

(b) removing the release material from the composite; and

(c) applying the composite to a liquid crystal display panel such that the adhesive adheres the heat spreader composite to the panel ensuring direct thermal contact between the heat spreader and the collection of light-emitting heat sources in the panel while the panel assumes any of a variety of orientations, wherein the heat spreader cools the collection of light-emitting heat sources in the liquid crystal display panel.

2. The method of claim 1 wherein the adhesive and release material provide an average release load of no greater than about 40 grams per centimeter at a release speed of one meter per second.

3. The method of claim 2 wherein the average release load is no greater than about 10 grams per centimeter at a release speed of one meter per second.

4. The method of claim 1 wherein the adhesive achieves an average lap shear adhesion strength of at least about 700 grams per square centimeter.

5. The method of claim 1 wherein the adhesive results in an increase in through thickness thermal resistance of the adhesive/heat spreader material of not more than about 35% as compared to the heat spreader material itself.

6. The method of claim 5 wherein the thickness of the adhesive is no greater than about 0.5 mils.

7. The method of claim 6 wherein the thickness of the adhesive is not greater than about 0.25 mils.

8. The method of claim 1 wherein the heat spreader material comprises a laminate comprising a plurality of sheets of compressed particles of exfoliated graphite.

9. A method for applying heat spreaders to a plurality of liquid crystal display panels which comprise a collection of light-emitting heat sources, the method comprising (a) providing a plurality of anisotropic heat spreader composites, each of which comprises a heat spreader material comprising at least one sheet of compressed particles of exfoliated graphite, the heat spreader composites each having an adhesive thereon and a release material positioned such that the adhesive is sandwiched between the heat spreader material and the release material, wherein the adhesive achieves a minimum lap shear adhesion strength of at least about 125 grams per square centimeter and no primer coating is required for adhesion of the adhesive to the heat spreader material;

(b) removing the release material from a plurality of the composites; and

(c) applying at least one of the composites to each of the plurality of liquid crystal display panels each such that the adhesive adheres the heat spreader composite to the liquid crystal display panel such that the heat spreader composite is in direct thermal contact with the collection of light-emitting heat sources in the liquid crystal display panel and cools and ameliorates the effects of hot spots generated by the panel.

10. The method of claim 9 wherein the release material and adhesive are selected to permit a predetermined rate of release of the release material without causing undesirable damage to the heat spreader material.

11. The method of claim 10 wherein the adhesive and release material provide an average release load of no greater than about 40 grams per centimeter at a release speed of one meter per second.

12. The method of claim 11 wherein the average release load is no greater than about 10 grams per centimeter at a release speed of one meter per second.

13. The method of claim 9 wherein the adhesive achieves an average lap shear adhesion strength of at least about 700 grams per square centimeter.

14. The method of claim 9 wherein the adhesive results in an increase in through thickness thermal resistance of the adhesive/heat spreader material of not more than about 35% as compared to the heat spreader material itself.

15. The method of claim 14 wherein the thickness of the adhesive is no greater than about 0.5 mils.

16. The method of claim 15 wherein the thickness of the adhesive is no greater than about 0.25 mils.

17. The method of claim 9 wherein the heat spreader material comprises a laminate comprising a plurality of sheets of compressed particles of exfoliated graphite.