Clip on heat sink

• US 20080310119A1
• Filed: 06/13/2007
• Published: 12/18/2008
• Est. Priority Date: 06/13/2007
• Status: Abandoned Application

• Current Assignee: Tellabs Bedford, Inc. (Infinera Corp.)
• Original Assignee: Tellabs Bedford, Inc. (Infinera Corp.)
• Inventors: Giacoma, Lawrence M.
• Application Number:
  US11/818,160
• Publication Number:
  US 20080310119A1
• Time in Patent Office: Days
• 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 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

Abstract

A heat sink according to an embodiment of the present invention can be attached to any device without printed circuit board (PCB) modification. The heat sink may clamp on device edges, which does not stress solder balls between the device and heat sink. The heat sink may be configured to be installed to or removed from the device without special tools. The heat sink may be extruded, machined, or die cast aluminum or other material to reduce part and tooling cost, and may be black anodized to be electrically non-conductive. A single-piece embodiment eliminates a need for a separate clip, thereby increasing heat transfer by as much as twenty-five percent or more over heat sinks employing clips. Further, wavy fins or other heat dissipation configurations may increase heat transfer by at least eleven percent, for a total heat transfer improvement of at least thirty-six percent over a two-part heat sink.

Claims

1. A heat sink comprising:

a contact plate with a conduction side and a convection side, the conduction side configured to be in thermal communication with a heat generating device;

a plurality of thermally conductive elements extending outward from the convection side of the contact plate;

spring clips extending outward from the contact plate and returning toward and below the contact plate, the spring clips having elasticity to enable bending outward from the contact plate and self-restoring inward toward the contact plate to self-couple with the heat generating device.

2. The heat sink of claim 1 wherein the spring clips are configured to bend substantially laterally outward from the contact plate.

3. The heat sink of claim 1 wherein the spring clips extend outward from the convection side of the contact plate.

4. The heat sink of claim 3 wherein the spring clips extend outward from the convection side of the contact plate at respective edges of the contact plate and return toward and below the respective edges of the contact plate.

5. The heat sink of claim 1 wherein the spring clips further include tabs at least partially extending under the heat generating device.

6. The heat sink of claim 5 wherein the tabs are angled relative to the conduction side of the contact plate.

7. The heat sink of claim 5 wherein the tabs are substantially parallel to the conduction side of the contact plate.

8. The heat sink of claim 1 wherein the spring clips further include:

a central portion; and

legs separated by the central portion by respective slits, the central portion configured to contact the heat generating device in a clamped state and the legs configured to be in an unclamped state while the central portion is in the clamped state.

9. The heat sink of claim 1 wherein a combination of the spring clips and the contact plate exerts forces on the heat generating device in a manner that does not affect a mechanical arrangement between the heat generating device and a member to which the heat generating device is coupled.

10. The heat sink of claim 9 wherein the spring clips exert at least some forces laterally inward on the heat generating device.

11. The heat sink of claim 9 wherein the spring clips exert at least some forces diagonally upward on the heat generating device.

12. The heat sink of claim 9 wherein the spring clips exert forces vertically upward and downward on the heat generating device.

13. The heat sink of claim 1 wherein the thermally conductive elements provide more convection surface area than if plate elements with flat surfaces.

14. The heat sink of claim 1 wherein the thermally conductive elements are configured to increase airflow across them.

15. The heat sink of claim 1 wherein the spring clips define slots to provide openings for a tool to bend the clips at a bend between extending outward and returning toward and below the contact plate.

16. A method of removably securing a heat sink comprising:

applying a restorative force to self-couple a heat sink to a heat generating device.

17. The method of claim 16 further comprising:

countering the restorative force to remove the heat sink from the heat generating device.

18. The method of claim 16 wherein applying the restorative force includes applying the restorative force from a convection side of the heat sink.

19. The method of claim 18 wherein applying the restorative force includes applying the restorative force from the edges of the convection side of heat sink.

20. The method of claim 16 wherein applying the restorative force includes applying a securing force to the underside of the heat generating device to minimize or prevent vertical movement of the heat sink on the heat generating device.

21. The method of claim 20 wherein applying the securing force includes applying the securing force at an angle relative to the underside of the heat generating device.

22. The method of claim 20 wherein applying the securing force includes applying the securing force substantially perpendicular to the underside of the heat generating device.

23. The method of claim 16 wherein applying the restorative force includes applying a securing force to an edge of the heat generating device to minimize or prevent horizontal movement of the heat sink on the heat generating device.

24. The method of claim 16 wherein applying the restorative force to the heat generating device is performed in a manner that does not affect a mechanical arrangement between the heat generating device and a member to which the heat generating device is coupled.

25. The method of claim 24 wherein applying the restorative force includes applying at least some restorative force laterally inward on the heat generating device.

26. The method of claim 24 wherein applying the restorative force includes applying at least some restorative force diagonally upward on the heat generating device.

27. The method of claim 24 wherein applying the restorative force includes applying restorative forces vertically upward and downward on the heat generating device.

28. The method of claim 17 wherein applying the restorative force includes resisting bending forces produced by a tool acting upon the heat sink to counter the restorative force.

29. A heat sink comprising:

means for dissipating heat from a heat generating device; and

means for self-coupling the heat dissipating means to the heat generating device.