Heat spreader for emissive display device

• US 20070077434A1
• Filed: 12/18/2006
• Published: 04/05/2007
• Est. Priority Date: 10/14/2003
• Status: Active Grant

• Current Assignee: NeoGraf Solutions, LLC
• Original Assignee: Graftech International Holdings Inc (Graftech International Limited)
• Inventors: Clovesko, Timothy, Norley, Julian, Smalc, Martin, Capp, Joseph
• Granted Patent: US 7,658,999 B2
• Time in Patent Office: Days
• US Class Current: 428/408
• CPC Class Codes: B32B 43/006 Delaminating
• 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 2211/66 Cooling arrangements cooling or supporting means not being part of the tube H05K
• CPC Class Codes: H01J 2217/492 Details
• CPC Class Codes: H01J 7/24 Cooling arrangements; Heating arrangements; Means for circulating gas or vapour within the discharge space
• CPC Class Codes: H01J 9/20 Manufacture of screens on or from which an image or pattern is formed, picked up, converted or stored; Applying coatings to the vessel
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 7/20963 Heat transfer by conduction from internal heat source to heat radiating structure H05K7/20972 takes precedence
• CPC Class Codes: Y10T 428/1314 Contains fabric, fiber particle, or filament made of glass, ceramic, or sintered, fused, fired, or calcined metal oxide, or metal carbide or other inorganic compound [e.g., fiber glass, mineral fiber, sand, etc.]
• CPC Class Codes: Y10T 428/14 Layer or component removable to expose adhesive
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

A heat spreader for a display device, such as a plasma display panel, a light emitting diode or a liquid crystal display, comprising at least one sheet of compressed particles of exfoliated graphite having a surface area greater than the surface area of that part of the back surface of the display device where a localized region of higher temperature is generated.

Claims

1. A heat spreader for a display device, comprising at least one sheet of compressed particles of exfoliated graphite having a surface area greater than the surface area of that part of the back surface of the display device where a localized region of higher temperature is generated.

2. The heat spreader of claim 1, wherein the display device is an emissive display device, and the at least one sheet of compressed particles of exfoliated graphite has a surface area greater than the surface area of that part of a discharge cell facing the back surface of the emissive display device.

3. The heat spreader of claim 2 wherein the emissive display device comprises a plasma display panel.

4. The heat spreader of claim 3 wherein the at least one sheet of compressed particles of exfoliated graphite has a surface area greater than the surface area of that part of a plurality of discharge cells facing the back surface of the plasma display panel

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

6. The heat spreader of claim 5 wherein the laminate comprises layers of a non-graphitic material.

7. The heat spreader of claim 1 wherein the heat spreader comprises an adhesive thereon and a release material positioned such that the adhesive is sandwiched between the heat spreader and the release material.

8. The heat spreader of claim 7 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.

9. The heat spreader of claim 8 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.

10. The heat spreader of claim 9 wherein the adhesive achieves a minimum lap shear adhesion strength of at least about 125 grams per square centimeter.

11. The heat spreader of claim 10 wherein the adhesive achieves an average lap shear adhesion strength of at least about 700 grams per square centimeter.

12. The heat spreader of claim 11 wherein the thickness of the adhesive is no greater than about 0.015 mm.

13. The heat spreader of claim 1 wherein at least one of the major surfaces is coated with a protective coating sufficient to inhibit flaking of particles of graphite.

14. The heat spreader of claim 13 wherein the protective coating comprises a metal or a thermoplastic material.

15. The heat spreader of claim 14 wherein the protective coating is no more than about 0.025 mm in thickness.

16. The heat spreader of claim 15 wherein the protective coating is effective to electrically isolate the coated major surface of the at least one sheet of compressed particles of exfoliated graphite.

17. The heat spreader of claim 12 wherein the at least one sheet of compressed particles of exfoliated graphite has edge surfaces, and at least one edge surface is coated with a protective coating sufficient to inhibit flaking of the particles of graphite.

18. The heat spreader of claim 12 which further comprises a layer of adhesive interposed between the protective coating and the at least one sheet of compressed particles of exfoliated graphite.

19. The heat spreader of claim 1 which further comprises a facing layer adhered to a surface thereof for being interposed between the sheet of compressed particles of exfoliated graphite and the display device.

20. The heat spreader of claim 19 wherein the facing layer comprises a metal.