Spring clamp assembly for improving thermal contact between stacked electronic components

• US 5,771,155 A
• Filed: 09/03/1996
• Issued: 06/23/1998
• Est. Priority Date: 09/03/1996
• Status: Expired due to Fees

• Current Assignee: Aavid Thermal Products Incorporated (Ansys Incorporated)
• Original Assignee: Aavid Thermal Products Incorporated (Ansys Incorporated)
• Inventors: Cook, Randolph H.
• Primary Examiner(s): Thompson, Gregory D.
• Application Number:
  US08/707,225
• Time in Patent Office: 658 Days
• Field of Search: 24/458, 24/510, 24/518, 165/80.2, 165/80.3, 165/185, 174/16.3, 248/510, 257/707, 257/713, 257/718-719, 257/726-727, 361/704, 361/707, 361/709-710, 361/715-722
• US Class Current: 361/710
• 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 spring clamp device providing a compressive stress to a stack of components includes a spring member and a bracket having attachment structure for engaging mating structure near the bottom of the stack. The bracket is first engaged with the mating structure such that it straddles the stack. The spring member is then latched to the bracket under tension in an assembled configuration, thereby applying an upward reaction on the mating structure with the attachment structure of the bracket and applying a downward reaction force to the top of the stack with the spring member. The oppositely directed forces apply a compressive stress to the stack, which improves thermal contact between the components.

Claims

1. A spring clamp device for clamping together a stack of electronic components, comprising:

a spring member including at least one torsion spring coil;

a first component of said stack having peripheral sides;

coupling means including structure for latching to said peripheral sides of said first component of said stack, said spring member further including a first connecting member for operatively connecting said spring coil to said coupling means at one of said peripheral sides and a second connecting member for operatively connecting said spring coil to said coupling means at another of said peripheral sides for tensioning said at least one coil in a clamped configuration such that a peripheral edge of said at least one coil urges a second component of said stack against said first component.

2. The spring clamp device of claim 1, wherein said said first connecting member and said second connecting member comprise a pair of arms extending from ends of said at least one coil, and wherein said coupling means includes a bracket comprising a cross member, legs depending from respective ends of said cross member, each leg including a surface for latching to one of said peripheral sides, and spring engaging members coupled to respective ends of said cross member for engaging one of said arms in said clamped configuration.

3. The spring clamp device of claim 2, wherein said spring engaging members are coupled to said respective ends of said cross member by respective upright arms extending up from said legs.

4. The spring clamp device of claim 2, wherein said surface for latching of each leg comprises an edge of an aperture formed in said leg, said apertures being structured for placement over respective bosses projecting from peripheral sides of the first component.

5. The spring clamp device of claim 4, wherein each leg includes an outwardly flared end.

6. The spring clamp device of claim 2, wherein said cross member comprises a central portion positioned such that said at least one coil bears against said central portion in said clamped configuration.

7. The spring clamp device of claim 6, wherein said central portion is wider than portions adjacent said central portion.

8. The spring clamp device of claim 6, wherein said central portion is laterally offset from an adjacent portion of said cross member.

9. The spring clamp device of claim 6, wherein said central portion includes structure for stabilizing said at least one coil in said clamped configuration.

10. The spring clamp device of claim 5, wherein said cross member is structured such that in said clamped configuration said at least one coil bears directly against said second component.

11. The spring clamp device of claim 10, wherein said cross member includes a central portion relieved under said at least one coil in said clamped configuration.

12. The spring clamp device of claim 10, wherein said cross member is positioned over said at least one coil distal said second component in said clamped configuration.

13. The spring clamp device of claim 12, wherein said cross member includes a narrowed portion and a widened portion, wherein said spring engaging members are formed on said legs.

14. The spring clamp device of claim 8, wherein one of said spring engaging members comprises a hooked member for releasably engaging one of said arms of said spring member.

15. The spring clamp device of claim 14, wherein the other of said spring engaging members comprises a hinge rotatably engaging the other of said arms of said spring member.

16. The spring clamp device of claim 1, wherein said spring member and said coupling means are formed of a single length of wire.

17. A spring clamp device for improving thermal contact between members of a stack of electronic components in an clamped configuration with the stack, comprising:

a torsion spring, including;

a coil having a central axis transverse to the direction of the compressive stress in the assembled configuration; and

a pair of spring arms extending outward from ends of the coil and defining an obtuse included angle; and

a bracket having an approximately H-shaped profile, including;

a cross member structured to span across a top component of the stack in the clamped configuration;

a leg depending downward from each end of the cross member and next to a side of the stacked components when spanned by the cross member, each leg comprising a surface for engaging a lower component of the stack below the top component; and

an upright arm extending upward from each end of the cross member, an upper end of each arm forming a spring engaging member for engaging a respective one of the spring arms, configured such that the spring is tensioned in the clamped configuration, in which the bracket spans the stacked components, the legs engage with the lower component and both spring arms engage with the spring engaging members, and such that a peripheral edge of the coil urges the top component toward the lower component to produce a compressive stress in the stack, whereby thermal contact between the components is improved.

18. The assembly of claim 17, wherein one of the spring engaging members forms a hinge with one of the spring arms.

19. The assembly of claim 17, wherein the bracket comprises a metal stamping and the spring comprises music wire.

20. A heat dissipating assembly, comprising:

an electronic device generating thermal energy during operation;

a heat sink mounted on top of the electronic device;

a spring clamp device including a torsion spring member comprising at least one coil and coupling means comprising structure for latching to peripheral sides of one of the electronic device and a socket in which the electronic device is mounted and for tensioning the at least one coil in a clamped configuration such that a peripheral edge of the at least one coil urges the heat sink against the electronic device.

21. The heat dissipating assembly of claim 20, wherein the latching structure latches to bosses projecting from the peripheral sides of the one of the electronic device and the socket.

22. The heat dissipating assembly of claim 21, wherein the spring member further includes a pair of arms extending from ends of the at least one coil, and wherein the coupling means comprises a bracket, including a cross member, legs depending from respective ends of the cross member, each leg including an aperture having an edge for latching to one of the bosses, and spring engaging members coupled to respective ends of the cross member for engaging one of the arms in the clamped configuration.

23. The heat dissipating assembly of claim 21, further comprising a circuit board on which the socket is mounted.

24. The heat dissipating assembly of claim 22, wherein the cross member comprises a central portion positioned such that the at least one coil bears against the central portion in the clamped configuration.

25. The heat dissipating assembly of claim 24, wherein the central portion is wider than portions adjacent the central portion.

26. The heat dissipating assembly of claim 24, wherein the central portion is laterally offset from an adjacent portion of the cross member.

27. The heat dissipating assembly of claim 24, wherein the central portion includes structure for stabilizing the at least one coil in the assembled configuration.

28. The heat dissipating assembly of claim 22, wherein the cross member is structured such that in the clamped configuration the at least one coil bears directly against the heat sink.

29. The heat dissipating assembly of claim 28, wherein the cross member includes a central portion relieved under the at least one coil in the assembled configuration.

30. The heat dissipating assembly of claim 28, wherein said cross member is positioned over the at least one coil distal the heat sink component in the assembled configuration.

31. The heat dissipating assembly of claim 30, wherein the spring engaging members are formed on the legs.

32. The heat dissipating assembly of claim 26, wherein one of the spring engaging members comprises a hooked member for releasably engaging one of the arms of the spring member, and wherein the other of the spring engaging members comprises a hinge rotatably engaging the other of the arms of the spring member.

33. The heat dissipating assembly of claim 23, wherein the spring member and the coupling means are formed of a single length of wire.

34. A method of improving thermal contact between an electronic device and a heat sink, comprising:

positioning the heat sink on top of the electronic device;

attaching a bracket to opposite sides of the electronic device;

linking a torsional spring member to the bracket under tension, producing an upward reaction on the electronic device and producing a downward reaction on the top of the heat sink.

35. A method of improving thermal contact between an electronic device and a heat sink, comprising:

mounting the electronic device in a socket having mounting bosses projecting from opposite peripheral sides;

positioning the heat sink on top of the electronic device;

straddling the heat sink with a bracket comprising a cross member, legs depending from the cross member, and spaced apart spring engaging members at opposite ends of the cross member;

engaging the legs to the mounting bosses by pressing the bracket downwards toward a top of the heat sink; and

latching a torsion spring member to the spring engaging members under tension, to apply an upward reaction force on the socket with the legs and to apply a downward reaction force to the top of the heat sink with the spring member.

36. The method of claim 35, further comprising mounting the socket on a circuit board prior to linking the torsion spring member.

37. The method of claim 35, wherein engaging the legs comprises engaging an aperture formed in each leg with a corresponding one of the mounting bosses.

38. The method of claim 37, wherein the torsion spring member includes an arm coupled to one of the legs, and wherein latching the torsion spring member comprises engaging another arm to a hook member coupled to the other leg, such that a central portion of the torsion spring member between the arms applies the downward reaction force.

39. The method of claim 38, wherein the torsion spring member comprises a torsion spring.

40. The method of claim 38, wherein applying the downward reaction force comprises transmitting the downward reaction force from the spring member to the top of the heat sink through the cross member.

41. A spring clamp device for clamping together a stack of electronic components that includes a top component and a lower component below said top component, comprising:

a torsion spring, including a coil having a central axis and arms extending outward from respective ends of said coil, said arms being in a first angular relation when said torsion spring is in a relaxed configuration; and

coupling means including first structure for latching to opposite peripheral sides of said lower component and second structure for latching said torsion spring in an assembled configuration clamping said stack wherein said arms are in a second angular relation relatively rotated from said first angular relation, said coil in said assembled configuration urging said top component towards said lower component to thereby clamp together said stack of electronic components.

42. The spring clamp device of claim 41, wherein said coupling means comprises a bracket.

43. The spring clamp device of claim 42, wherein said bracket comprises a cross member adapted to straddle the stack, said first structure comprises a leg extending from each end of said cross member, each leg including a surface configured for engaging said peripheral side of said lower component, and said second structure comprises a spring engaging member coupled to each end of said cross member for engaging a respective one of said arms in said assembled configuration.

44. The spring clamp device of claim 43, wherein said cross member comprises a central portion positioned such that said coil bears against said central portion in said assembled configuration.

45. The spring clamp device of claim 44, wherein said central portion is wider than portions adjacent said central portion.

46. The spring clamp device of claim 44, wherein said central portion is laterally offset from an adjacent portion of said cross member.

47. The spring clamp device of claim 44, wherein said central portion includes structure for stabilizing said coil in said assembled configuration.

48. The spring clamp device of claim 43, wherein said cross member is structured such that in said assembled configuration said coil bears directly against said top component.

49. The spring clamp device of claim 48, wherein said cross member includes a central portion relieved under said coil in said assembled configuration.

50. The spring clamp device of claim 48, wherein said cross member is positioned over said coil distal said top component in said assembled configuration.

51. The spring clamp device of claim 50, wherein said cross member includes a narrowed portion and a widened portion, wherein said spring engaging members are formed on said legs.

52. The spring clamp device of claim 43 wherein each spring engaging member is formed on an upright arm extending over one of said legs, said bracket having a substantially H-shaped profile.

53. The spring clamp device of claim 43, wherein one of said arms is rotatably coupled to one of said spring engaging members.

54. The spring clamp device of claim 41, wherein said torsion spring includes more than one coil.