Heat spreader for emissive display device

• US 10,440,865 B2
• Filed: 10/31/2006
• Issued: 10/08/2019
• Est. Priority Date: 10/14/2003
• Status: Expired due to Term

• Current Assignee: NeoGraf Solutions, LLC
• Original Assignee: NeoGraf Solutions, LLC
• Inventors: Clovesko, Timothy, Norley, Julian, Smalc, Martin David, Capp, Joseph Paul
• Primary Examiner(s): Miller, Daniel H
• Application Number:
  US11/590,061
• Publication Number:
  US 20070042188A1
• Time in Patent Office: 4,725 Days
• Field of Search: 428408, 345 60, 185165, 423448, 4234471, 4234472, 165185
• 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: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• 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 428/24273 including aperture
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

A heat spreader for an emissive display device, such as a plasma display panel or a light emitting diode, comprising at least one sheet of compressed particles of exfoliated graphite having a surface area greater than the surface area of that part of a discharge cell facing the back surface of the device.

Claims

1. A display device comprising a display panel having a size of at least one meter, a plurality of heat sources, and a thermal stress reduction system which comprises a heat spreader including a sheet of compressed particles of exfoliated graphite having first and second major surfaces, the graphite sheet having a thickness of from about 0.25 mm to about 1.0 mm and a surface area larger than the surface area of one of the heat sources, wherein the first major surface has a pressure sensitive acrylic adhesive adhered thereon to permit substantially all of the first major surface to be in thermal contact with the plurality of heat sources in the display device wherein the adhesive has a release load of no greater than 40 g/cm at a release speed of one meter per second and achieves a minimum lap shear adhesion strength of at least about 125 grams per square centimeter, and further wherein the graphite sheet has a density of from about 1.6 g/cc, to about 1.9 g/cc and a plastic backing layer on the second major surface.

2. The display device of claim 1 which comprises a plasma display panel.

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

4. The display device of claim 1 wherein the adhesive results in an increase in through thickness thermal resistance of the heat spreader of not more than about 35% as compared to the graphite sheet.

5. The display device of claim 4 wherein the thickness of the adhesive is no greater than about 0.015 mm.

6. The display device of claim 5 wherein the thickness of the adhesive is no greater than about 0.006 mm.

7. A display device having a display panel having a size of at least one meter, a plurality of heat sources, and a thermal stress reduction system, the system consists essentially of a heat spreader which includes a sheet of compressed particles of exfoliated graphite having first and second major surfaces, the graphite sheet having a thickness of from about 0.25 to about 1.0 mm and a surface area larger than the surface area of one of the heat sources, wherein the first major surface has a pressure sensitive acrylic adhesive adhered thereon adhering the graphite sheet to the panel to permit substantially all of the first major surface to be in thermal contact with the plurality of heat sources in the display device, wherein the adhesive has a release load of no greater than 40 g/cm at a release speed of one meter per second and achieves a minimum lap shear adhesion strength of at least about 125 grams per square centimeter, and further wherein the graphite sheet has a density of from about 1.6 g/cc to about 1.9 g/cc and a plastic backing layer on the second major surface.

8. The display device of claim 7 wherein the release load comprises no greater than 20 g/cm.

9. The display device of claim 8 wherein the release load comprises about 10 g/cm.

13. The display device of claim 7 wherein in a thickness of the adhesive comprises no more than 0.015 mm.

10. A display device including a display panel having a size of at least one meter, a plurality of heat sources, and a thermal stress reduction system, the system consists of a heat spreader which includes a sheet of compressed particles of exfoliated graphite having first and second major surfaces, the graphite sheet having a thickness of from about 0.25 to about 1.0 mm, wherein the graphite sheet is anisotropic and has a surface area larger than the surface area of one of the heat sources, and wherein the first major surface has a pressure sensitive acrylic adhesive adhered thereon to permit substantially all of the first major surface to be in thermal contact with the plurality of heat sources in the display device, wherein the adhesive has a release load of no greater than 40 g/cm at a release speed of one meter per second and achieves a minimum lap shear adhesion strength of at least about 125 grams per square centimeter, and further wherein the graphite sheet has a density of from about 1.6 g/cc to about 1.9 g/cc and a plastic backing layer on the second major surface.

11. The display device of claim 10 wherein the release load comprises no greater than 20 g/cm.

12. The display device of claim 11 wherein the release load comprises about 10 g/cm.

14. The display device of claim 10 wherein in a thickness of the adhesive comprises no more than 0.015 mm.