Method of making an electronic device

• US 8,773,856 B2
• Filed: 11/07/2011
• Issued: 07/08/2014
• Est. Priority Date: 11/08/2010
• Status: Expired due to Fees

• Current Assignee: NeoGraf Solutions, LLC
• Original Assignee: Graftech International Holdings Inc (Graftech International Limited)
• Inventors: Petroski, James T.
• Primary Examiner(s): Wilson, Adrian S
• Application Number:
  US13/290,382
• Publication Number:
  US 20120113595A1
• Time in Patent Office: 974 Days
• Field of Search: 361/688, 361/696, 361/701, 361/702, 361/704, 361/705, 361/708, 361717-722
• US Class Current: 361/705
• CPC Class Codes: B32B 2309/105 Thickness
• CPC Class Codes: B32B 2313/04 Carbon
• CPC Class Codes: B32B 2457/206 Organic displays, e.g. OLED
• CPC Class Codes: B32B 37/12 characterised by using adhesives
• CPC Class Codes: H05K 1/0201 Thermal arrangements, e.g. for cooling, heating or preventing overheating
• CPC Class Codes: H05K 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.

Abstract

An electronic device includes an electronic component with a mating surface. A thermal interface sheet is attached to the mating surface. A substrate carries the electronic device and includes a face. The electronic component is secured to the substrate with the thermal interface sheet positioned between the mating surface and the face. The mating surface is relatively less flat than the face and the mating surface is relatively smoother than the face.

Claims

1. An electronic device comprising:

an electronic component having a mating surface;

a thermal interface sheet attached to the mating surface;

a substrate having a face, the electronic component secured to said substrate and said thermal interface sheet positioned between said mating surface and said face; and

wherein the mating surface has a flatness value and the face has a surface roughness, the mating surface flatness value at least about 15% greater than the face surface roughness when measured in the same units.

2. The method of claim 1 wherein the mating surface has a concave configuration.

3. The method of claim 1 wherein the mating surface has a saddle point configuration.

4. The method of claim 1 wherein the mating surface has a generally corrugated configuration.

5. The method of claim 1 wherein an adhesive attaches the thermal interface sheet to the mating surface.

6. The method of claim 1 wherein the mating surface flatness value at least about 20% greater than the face surface roughness when measured in the same units.

7. The method of claim 1 wherein a surface area of a major surface of the thermal interface sheet not larger than about the surface of the face of the substrate.

8. The method of claim 1 wherein the electronic component comprises a PCB having an LED or an OLED.

9. The method of claim 1 wherein said thermal interface sheet comprises a compressed mass of exfoliated graphite particles.

10. The method of claim 1 wherein said thermal interface sheet comprises a graphitized polyimide sheet.

11. The method of claim 5 wherein said adhesive comprises a layer no more than about 0.0015 mm thick.

12. The method of claim 1 further including a protective coating adjacent to said thermal interface sheet.

13. The method of claim 12 wherein said protective coating not more than about 0.025 mm thick.

14. The method of claim 13 wherein said protective coating not more than about 0.005 mm thick.

15. The method of claim 1 wherein said substrate comprises a heat dissipating device.

16. The method of claim 1 wherein said substrate substantially surrounds said device.