Embossed heat spreader

• US 8,081,474 B1
• Filed: 09/02/2008
• Issued: 12/20/2011
• Est. Priority Date: 12/18/2007
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Smith, Michael John Sebastian, Zohni, Wael O., Schmidt, William L., Plunkett, Jeremy Matthew
• Primary Examiner(s): Thompson, Gregory
• Application Number:
  US12/203,100
• Time in Patent Office: 1,204 Days
• Field of Search: None
• US Class Current: 361/719
• CPC Class Codes: H01L 23/367 Cooling facilitated by shape of device H01L23/38, H01L23/40, H01L23/42, H01L23/44, H01L23/46 take precedence
• CPC Class Codes: H01L 23/4093 Snap-on arrangements, e.g. clips
• CPC Class Codes: H01L 23/42 Fillings or auxiliary members in containers or encapsulations selected or arranged to facilitate heating or cooling
• 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 7/20509 Multiple-component heat spreaders; Multi-component heat-conducting support plates; Multi-component non-closed heat-conducting structures

Abstract

One embodiment of the present invention sets forth a heat spreader module for dissipating thermal heat generated by electronic components. The assembly comprises a printed circuit board (PCB), electronic components disposed on the PCB, a thermal interface material (TIM) thermally coupled to the electronic components, and a heat spreader plate thermally coupled to the TIM. The heat spreader plate includes an embossed pattern. Consequently, surface area available for heat conduction between the heat spreader plate and surrounding medium may be increased relative to the prior art designs.

Claims

1. An apparatus comprising:

a printed circuit board (PCB);

electronic components disposed on the PCB;

a thermal interface material (TIM) thermally coupled to the electronic components; and

a heat spreader plate with a surface thermally coupled to the TIM, the surface of the heat spreader plate having edges and an embossed pattern with embossed segments having open ends;

wherein

a portion of the heat spreader plate extends between each open end and a closest one of the edges.

2. The apparatus of claim 1, wherein the embossed pattern comprises one or more long embossed segments that run substantially an entire length of a longitudinal one of the edges of the surface of the heat spreader plate and two or more short embossed segments such that, cumulatively, the two or more short embossed segments run substantially the entire length of the longitudinal one of the edges of the surface of the heat spreader plate.

3. The apparatus of claim 2, wherein the one or more long embossed segments and the two or more short embossed segments have open ends.

4. The apparatus of claim 1, wherein the open ends are expanded.

5. The apparatus of claim 2, wherein the two or more shorter segments are disposed so as to provide location guidance for one or more retention clips.

6. The apparatus of claim 2, wherein the two or more shorter segments comprises two or more groups of substantially parallel shorter segments, wherein each group of substantially shorter segments is separated from another one of the groups of substantially shorter segments by a part of the heat spreader plate.

7. The apparatus of claim 1, wherein each embossed segment has a concave side and a convex side, wherein the convex side faces away from the electronic components.

8. The apparatus of claim 1, wherein the embossed segments having open ends are stamped.

9. The apparatus of claim 8, wherein a surface of the heat spreader plate that has been stamped to create the embossed segments is physically in contact with the TIM.

10. The apparatus of claim 1, wherein the heat spreader plate includes a concave side and a convex side, and the convex side is facing away from the electronic components.

11. The apparatus of claim 1, wherein a shape of the heat spreader plate is substantially planar.

12. The apparatus of claim 1, wherein a shape of the heat spreader plate conforms to a contour of the electronic components.

13. The apparatus of claim 12, wherein the shape of the heat spreader plate comprises an alternating series of high planes and low planes.

14. The apparatus of claim 12, wherein the embossed pattern follows the shape of the heat spreader plate.

15. The apparatus of claim 1, further comprising a fastening mechanism adapted to clamp the PCB, the electronic components, the TIM, and the heat spreader plate.

16. The apparatus of claim 15, wherein the fastening mechanism comprises one or more C-clips.

17. The apparatus of claim 1, wherein the embossed pattern comprises one or more long embossed segments that run substantially an entire length of a longitudinal edge of the heat spreader plate.

18. The apparatus of claim 1, wherein the embossed pattern comprises two or more short embossed segments such that, cumulatively, the two or more short embossed segments run substantially an entire length of a longitudinal edge of the heat spreader plate.

19. The apparatus of claim 18, wherein the two or more short embossed segments are adapted to provide location guidance for retention clips.

20. The apparatus of claim 1, wherein the TIM comprises a lamination layer.

21. The apparatus of claim 20, wherein the lamination layer comprises at least one of a conductive particle filled silicon rubber, a foamed thermoset material, a phase change polymer, and a gap filler material.

22. The apparatus of claim 1, wherein the TIM provides an encasing for the electronic components.

23. The apparatus of claim 22, wherein the TIM comprises a phase change polymer or a material with a non-adhesive layer.

24. The apparatus of claim 23, wherein the material with a non-adhesive layer comprises a metal or a plastic film.

25. The apparatus of claim 1, wherein a thickness of the heat spreader plate is between 2 millimeters and 2.5 millimeters.

26. The apparatus of claim 1, wherein the TIM is shaped to thermally connect a first area of the PCB to a second area of the PCB, wherein the first area and the second area do not overlap.

27. The apparatus of claim 26, wherein thermal conductivity of the TIM is higher than thermal conductivity of a material comprising the PCB.

28. The apparatus of claim 1, wherein the heat spreader plate comprises openings adapted to allow interchange of a cooling fluid between inner and outer surfaces of the heat spreader plate.

29. The apparatus of claim 28, wherein the openings are disposed at specific positions relative to the embossed pattern such that air flow over the openings is accelerated relative to the average air flow velocity.

30. The apparatus of claim 1, wherein the heat spreader plate comprises a mating surface adapted to allow for heat conduction to an external heat sink or a metal structure.

31. The apparatus of claim 30, wherein the metal structure comprises a system chassis.

32. The apparatus of claim 30, wherein the apparatus is a part of a memory device comprising a motherboard, and the mating surface comprises a flat bent tab and/or machined edge designed to lie within a plane parallel to the motherboard and perpendicular to the PCB and a heat spreader plate seating plane.

33. The apparatus of claim 1, wherein the heat spreader plate comprises a flexible tape or a sticker adapted to have negligible resistance to lengthwise compressive forces acting on the heat spreader plate.

34. The apparatus of claim 1, wherein the apparatus is a part of a memory device.

35. The apparatus of claim 34, wherein the memory device is arranged in a stack with other memory devices.

36. The apparatus of claim 34, wherein the memory device comprises a dynamic random access memory chip.

37. The apparatus of claim 1, wherein the apparatus is included in a dual in-line memory module (DIMM).

38. The apparatus of claim 37, wherein:

the DIMM is mounted into a DIMM socket included in an assembly comprising multiple DIMMS and a motherboard, and the DIMM socket is electrically connected to the motherboard.

39. The apparatus of claim 1, wherein the apparatus is included within a computing device.