Conforming heat sink assembly

• US 4,974,119 A
• Filed: 05/29/1990
• Issued: 11/27/1990
• Est. Priority Date: 09/14/1988
• Status: Expired due to Fees

• Current Assignee: Charles Stark Draper Laboratory Incorporated
• Original Assignee: Charles Stark Draper Laboratory Incorporated
• Inventors: Martin, Jacob H.
• Primary Examiner(s): Tolin, Gerald P.
• Application Number:
  US07/533,957
• Time in Patent Office: 182 Days
• Field of Search: 357/81, 174/16.3, 174/252, 165/80.3, 165/185, 361/386, 361/387, 361/388, 361/400, 361/405, 361/410
• US Class Current: 361/720
• CPC Class Codes: H05K 1/0272 Adaptations for fluid transport, e.g. channels, holes
• CPC Class Codes: H05K 2201/0133 Elastomeric or compliant polymer elastomeric conductor H05K2201/0314
• CPC Class Codes: H05K 2201/10598 Means for fastening a component, a casing or a heat sink whereby a pressure is exerted on the component towards the PCB
• CPC Class Codes: H05K 3/0061 onto a metallic substrate, e.g. a heat sink heat sinks for electric apparatus H05K7/20
• CPC Class Codes: H05K 3/3447 Lead-in-hole components H05K3/3415 takes precedence
• CPC Class Codes: H05K 7/205 Heat-dissipating body thermally connected to heat generating element via thermal paths through printed circuit board [PCB] details of PCBs relating to heat transfer H05K1/0201
• CPC Class Codes: H05K 7/20509 Multiple-component heat spreaders; Multi-component heat-conducting support plates; Multi-component non-closed heat-conducting structures

Abstract

A conforming heat sink assembly including a heat dispersive element is mounted in spaced relationship to a surface from which heat is to be conducted. A thermal interface is provided for coupling the heat dispersive element to the surface from which heat is to be conducted. The thermal interface includes an elastomeric member which occupies only a portion of a volume defined by mounting the heat dispersive element proximate the surface from which heat is to be conducted. The unoccupied volume allows the elastomeric member to easily conform to the irregular surface from which heat is to be conducted to enhance thermal conductivity from the surface to the heat dispersive member.

Claims

1. A heat sink assembly comprising:

a heat dispersing member;

an elastomeric member disposed between said heat dispersing member and an irregular surface to be cooled having protrusions, which physically contacts said heat dispersing member and said irregular surface;

at least one of said heat dispersing member and said elastomeric member defining a plurality of voids at a junction thereof, each of said voids disposed along the junction between said elastomeric member and said heat dispersing member and said voids spaced with respect to each other and are aligned with same protrusions, to enable said protrusions to displace said elastomeric member into said voids, to increase the amount of surface area of said elastomeric member that is in contact with said irregular surface and enhance thermal conductivity from said irregular surface to said heat dispersing member.

2. The heat sink assembly of claim 1 in which said elastomeric member is thermally conductive and electrically insulative.

3. The heat sink assembly of claim 1 in which said voids are established by periodic channels or holes.

4. The heat sink assembly of claim 1 in which said elastomeric member exhibits a periodic undulating shape.

5. A heat sink assembly comprising:

a heat dispersing member;

means mounting said dispersing member in spaced relationship to a device to be cooled having protrusions, to establish a first volume between said heat dispersing member and the device and for establishing a clamping force; and

an elastomeric, thermally conductive member disposed in said first volume, at least one of said elastomeric member and said heat dispersing member defining a plurality of voids at a junction thereof, each of said voids disposed along the junction between said elastomeric member and said heat dispersing member and said voids spaced with respect to each other and are aligned with said protrusions, to enable said elastomeric member to be deformed and displaced by said protrusions into at least a portion of the unoccupied portion of said first volume to relieve stress generated by the clamping force of said means mounting between said heat dispersing member and said device to be cooled.

6. The heat sink assembly of claim 5 in which said elastomeric member is electrically insulative.

7. The heat sink assembly of claim 5 in which said elastomeric member includes a silicone material.

8. The heat sink assembly of claim 5 in which said elastomeric member contains one or more thermally conductive fillers.

9. The heat sink assembly of claim 8 in which said filler is selected from the group including boron nitride, aluminum oxide, silicon carbide, aluminum nitride, magnesium oxide, and beryllium oxide.

10. The heat sink assembly of claim 5 in which said elastomeric member defines a plurality of voids.

11. The heat sink assembly of claim 10 in which said voids are located on a surface of said elastomeric member.

12. The heat sink assembly of claim 11 in which said voids are established by a plurality of generally parallel channels which extend substantially in a first direction and are generally parallel in a second direction transverse to said first direction.

13. The heat sink assembly of claim 12 in which said voids are further established by a second plurality of channels which extend substantially in said second direction and are generally parallel in said first direction.

14. The heat sink assembly of claim 5 in which said elastomeric member exhibits a periodic undulating shape.

15. The heat sink assembly of claim 5 in which said heat dispersing member defines a plurality of voids.

16. The heat sink assembly of claim 15 in which said voids are located on the surface of said heat dispersing member.

17. The heat sink assembly of claim 15 in which said voids are established by a plurality of generally parallel.

18. A thermal interface comprising:

a thermally conductive and electrically insulative elastomeric member having first and second sides, a plurality of recesses defined by said elastomeric member on said first side, said elastomeric member disposed between an irregular surface to be cooled having protrusions and a heat dispersing member with said second side toward said irregular surface, said recesses spaced with respect to each other and are aligned with said protrusions, to enable said elastomeric member to be displaced into said recesses by said protrusions, to increase the surface area of said elastomeric member that is in contact with said irregular surface and enhance thermal conductivity from said irregular surface to said heat dispersing member.

19. The thermal interface of claim 18 in which said recesses are established by periodic channels or holes.

20. The thermal interface of claim 19 in which said recesses are established by periodic undulations.

21. The thermal interface of claim 18 in which said elastomeric member includes a silicone material.

22. The thermal interface of claim 18 in which said elastomeric member contains one or more thermally conductive fillers.

23. The thermal interface of claim 22 in which said filler is selected from the group including boron nitride, aluminum oxide, silicon carbide, aluminum nitride, magnesium oxide, and beryllium oxide.

24. A heat sink assembly comprising:

a printed circuit board including a first surface having at least one heat generating source, and a second, irregular surface having a plurality of protrusions from which heat is to be conducted;

a heat dispersing member;

means mounting said heat dispersing member proximate to said second surface of said printed circuit board;

an elastomeric member disposed between said second surface and said heat dispersing member; and

at least one of said heat dispersing member and said elastomeric member defining a plurality of voids at a junction thereof, each of said voids disposed along the junction between said elastomeric member and said heat dispersing member and said voids spaced with respect to each other and are aligned with said protrusions, said elastomeric member deformed by said protrusions and conformed to said irregular surface to enable said elastomeric member to be displaced into said voids by said irregular surface, to increase surface area of said elastomeric member that is in contact with said irregular surface and enhance thermal conductivity from said irregular surface to said heat dispersing member.

25. The heat sink assembly claim 24 in which said heat generating source includes at least one electronic component and said irregularities of said second surface include a plurality of leads of a said electronic component.

26. The heat sink assembly of claim 24 in which said voids are recesses established by periodic channels.

27. The heat sink assembly of claim 24 in which said elastomeric member is electrically insulative and thermally conductive.

28. The heat sink assembly of claim 27 in which said elastomeric member includes a silicone material and a thermally conductive filler from the group consisting of boron nitride, aluminum oxide, silicon carbide, aluminum nitride, magnesium oxide, and beryllium oxide.