Flexible heat transfer device and method

• US 6,131,651 A
• Filed: 09/16/1998
• Issued: 10/17/2000
• Est. Priority Date: 09/16/1998
• Status: Expired due to Term

• Current Assignee: Momentive Performance Materials Incorporated (Momentive Performance Materials Holdings LLC)
• Original Assignee: Advanced Ceramics Corporation (General Electric Company)
• Inventors: Richey, Joseph B. III
• Primary Examiner(s): Lazarus, Ira S.
• Assistant Examiner(s): MCKINNON, TERRELL L
• Application Number:
  US09/154,253
• Time in Patent Office: 762 Days
• Field of Search: 165/80.2, 165/185, 165/104.33, 165/46, 174/16.3, 361/386, 428/112, 428/320.2, 428/117, 428/118, 428/131, 252/511
• US Class Current: 165/185
• CPC Class Codes: F28F 13/00 Arrangements for modifying heat-transfer, e.g. increasing, decreasing F28F1/00 - F28F11/00 take precedence
• CPC Class Codes: H01L 23/36 Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks H01L23/28, H01L23/40, H01L23/42, H01L23/44, H01L23/46 take precedence; heating H01L23/345
• CPC Class Codes: H01L 23/3733 having a heterogeneous or anisotropic structure, e.g. powder or fibres in a matrix, wire mesh, porous structures H01L23/3732, H01L23/3737 take precedence
• 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: Y10T 428/24157 Filled honeycomb cells [e.g., solid substance in cavities, etc.]
• CPC Class Codes: Y10T 428/249994 Composite having a component wherein a constituent is liquid or is contained within preformed walls [e.g., impregnant-filled, previously void containing component, etc.]

Abstract

A thin flexible heat transfer device for transferring heat from a heat source to a heat sink which may be located a substantial distance apart from each other. The heat transfer device includes a thin sheet of a non-structural, high thermal conductivity core material consisting of pyrolytic graphite or highly ordered pyrolytic graphite of a thickness between 2 microns and 2 mm and a pair of flexible face sheets each of a metallic composition having a maximum thickness of less than 25 mils disposed upon opposing surfaces of said core material to form a sandwich construction in cross section with the sheet of core material having a width smaller than the width of said face sheets such that the face sheets overlap the width of said core material around the perimeter of the device for enclosing and sealing the core material there within.

Claims

1. A thin flexible heat transfer device of indefinite length for transferring heat from a heat source to a heat sink which may be located a substantial distance apart from one another comprising:

a thin sheet of a non-structural, high thermal conductivity core material consisting of pyrolytic graphite or highly ordered pyrolytic graphite having an in-plane thermal conductivity of greater than 200 W/mK and a thickness of between 2 microns and 2 mm;

a pair of flexible face sheets each of a metallic composition having a maximum thickness of less than 25 mils disposed upon opposing surfaces of said core material to form a sandwich construction in cross section with the sheet of core material having a width smaller than the width of said face sheets such that the face sheets overlap the width of said core material and with said face sheets being bonded to one another at least around the perimeter of said device for enclosing and sealing said core material there within.

2. A heat transfer device as defined in claim 1 further comprising via holes in said core material.

3. A heat transfer device as defined in claim 2 wherein said face sheets are bonded by means of an adhesive agent selected from the group consisting of an organic adhesive, an inorganic adhesive, a solder, a brazing alloy and eutectic mixtures of two or more metals.

4. A heat transfer device as defined in claim 3 wherein said via holes are filled with said bonding agent.

5. A heat transfer device as defined in claim 4 wherein said bonding agent is of a thickness between 0.5 and 1 millimeter.

6. A heat transfer device as defined in claim 5 wherein the volume ratio of core material to face sheet plus bonding agent is between about 5 and 95%.

7. A heat transfer device as defined in claim 2 wherein the metallic composition of each face sheet is selected from the group consisting of aluminum, copper, silver, gold, nickel, beryllium, tin, lead, steel, Kovar, copper-tungsten composites, copper-molybdenum composites and tin-lead composites.

8. A heat transfer device as defined in claim 7 wherein the in-plane thermal conductivity of the core material is greater than 200 W/mK.

9. A heat transfer device as defined in claim 4 wherein said bonding agent is an organic adhesive selected from the group consisting of thermoset, acrylics and thermoplastics.