Dual spring clip attachment mechanism for controlled pressure interface thermal solution on processor cartridges

• US 6,381,136 B1
• Filed: 04/03/2000
• Issued: 04/30/2002
• Est. Priority Date: 09/30/1996
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Topic, Lee, Thurston, Mark, Chung, Yoke, Nelson, Daryl J., Stark, Michael, Rutigliano, Michael
• Primary Examiner(s): THOMPSON, GREGORY D
• Application Number:
  US09/541,822
• Time in Patent Office: 757 Days
• Field of Search: 165/80.2, 165/185, 174/16.3, 257/718-719, 257/726-727, 361/704, 361/707, 361/709-710, 361/715, 361/716-721, 361/737, 361/753, 361/759
• US Class Current: 361/704
• CPC Class Codes: G06F 1/184 Mounting of motherboards
• CPC Class Codes: G06F 1/185 Mounting of expansion boards
• CPC Class Codes: G06F 1/186 Securing of expansion boards in correspondence to slots provided at the computer enclosure
• CPC Class Codes: G06F 1/20 Cooling means
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 23/4093 Snap-on arrangements, e.g. clips
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H05K 7/1431 Retention mechanisms for CPU modules
• CPC Class Codes: H05K 7/20 Modifications to facilitate cooling, ventilating, or heating
• CPC Class Codes: H05K 7/20418 the radiating structures being additional and fastened onto the housing

Abstract

An electronic cartridge that includes a pair of spring clips which attach a thermal element to an integrated circuit or an integrated circuit package. The integrated circuit/package is mounted to a substrate. The substrate may be a printed circuit board. The cartridge may have a plurality of pins that extend from the thermal element and through the substrate. Each spring clip may have a pair of bent portions that are attached to the pins of the thermal element. The spring clip exerts a pull force that pulls the thermal element into the integrated circuit/package. The bent ports can be deflected so that at least a minimum pull force is always exerted onto the thermal element even with dimensional variations in the parts of the cartridge. The bent portions can therefore accommodate for tolerances in the cartridge while clamping the thermal element to the integrated circuit/package.

Claims

1. An electronic cartridge, comprising:

a substrate;

an integrated circuit mounted to said substrate;

a thermal element adjacent to said integrated circuit;

a pin that extends from said thermal element and through said substrate; and

,

a spring clip attached to said pin of said thermal element.

2. The cartridge as recited in claim 1, wherein said spring clip has a bent portion which exerts a force that pulls said thermal element toward said integrated circuit.

3. The cartridge as recited in claim 1, wherein said pin is inserted through a slot of said spring clip.

4. The cartridge as recited in claim 3, wherein said pin has a head portion and a groove that capture said spring clip.

5. The cartridge as recited in claim 1, further comprising a thermal grease located between said thermal element and said integrated circuit.

6. The cartridge as recited in claim 1, wherein said pin has a stud portion that extends from a shoulder of said pin, said stud portion being inserted into said thermal element.

7. A fastener to assemble an electronic cartridge, comprising:

a shoulder to limit insertion of said fastener into a thermal plate,

a stud portion that extends from said shoulder on a first side,

a neck portion that extends from said shoulder on a second side opposite said first side,

a head portion at an end of said neck portion on said second side,

said neck portion having a groove on said second side near said head portion,

said groove to engage a spring clip such that said fastener is prevented from being pulled out there from, and

said stud portion to couple into an opening in a thermal plate.

8. The fastener as recited in claim 7, further comprising:

a plastic bushing attached to said stud portion,

said stud portion and said plastic bushing to be pressed into an opening in a thermal plate.

9. The fastener as recited in claim 7 wherein,

said head portion of said fastener to engage a slot of a spring clip.

10. The fastener as recited in claim 7 wherein,

said groove to receive a pair of opposing edges of a spring clip.

11. The fastener as recited in claim 7 wherein,

the fastener to couple to a thermal plate at one end, extend through a substrate, and couple to a spring clip at an opposite end.

12. The fastener as recited claim 7 wherein,

said stud portion includes threads suitable to screw said fastener into an opening in a thermal plate.

13. An electronic cartridge, comprising:

a substrate having an upper and a lower edge, the substrate having a first plurality of holes situated along the upper and lower edges of the substrate;

an integrated circuit package mounted to the substrate;

a thermal element adjacent to the integrated circuit package, the thermal element having a plurality of holes, at least two of the plurality of holes in the thermal element corresponding to at least two of the first plurality of holes situated along the upper and lower edges of the substrate;

a plurality of first pins having a first and second end, the second end having a plurality of threads, the plurality of first pins having the second end screwed into the plurality of holes of the thermal element and the first end inserted through a second plurality of holes of the substrate; and

,

a pair of spring clips attached to the plurality of first pins near the first end to hold the thermal element pressed against the integrated circuit package.

14. The electronic cartridge of claim 13, wherein,

the pair of spring clips each have bent portions located at opposing edges of each which are deflected such that the pair of spring clips exert a pull force which pulls the thermal element into the integrated circuit package.

15. The electronic cartridge of claim 13, wherein,

the pair of spring clips each have a pair of slots, each slot respectively engaged into a groove located on a neck portion of each of the plurality of first pins near the first end.

16. The electronic cartridge of claim 15, wherein,

each slot has opposing edges residing in the groove of each of the plurality of first pins near the first end.

17. The electronic cartridge of claim 13, wherein,

the substrat Contains a plurality of conductive pads, the conductive pads to be inserted into a card edge electrical connector.

18. The electronic cartridge of claim 13, wherein,

each of the plurality of first pins has a stud portion extending from a shoulder, the stud portion having the plurality of threads in the second end to screw into the thermal element to a depth limited by the shoulder.

19. The electronic cartridge of claim 13, further comprising:

a heat sink that is mounted to the thermal element.

20. The electronic cartridge of claim 13, further comprising:

a cover wherein the cover and the thermal element fully enclose the integrated circuit package.

21. The electronic cartridge of claim 20, further comprising:

a plurality of second pins coupled to the thermal element at a second end and coupled to the cover at a first end.

22. The electronic cartridge of claim 21, wherein,

each of the plurality of second pins includes

a stud portion that extends from a shoulder, and

a plastic bushing pressed onto the stud portion and pressed into the thermal element to secure the thermal element to the cover.

23. The electronic cartridge of claim 22, wherein,

the shoulder of each limits insertion depth of the plurality of second pins.

24. A method to assemble an electronic cartridge comprising:

attaching an integrated circuit package to a substrate, the substrate having an upper edge and a lower edge and a first plurality of holes;

coupling a plurality of first pins to a thermal element;

sliding the plurality of first pins coupled to the thermal element through the first plurality of holes to thermally couple the thermal element to the integrated circuit package; and

snapping at least one spring clip onto a pair of the plurality of first pins to secure the thermal element to the substrate.

25. The method of claim 24 further comprising:

prior to the sliding of the plurality of first pins,

pressing plastic bushings onto a stud portion of each of a plurality of second pins,

coupling the plurality of second pins including the plastic bushings to the thermal element, and

sliding the plurality of second pins through a second plurality of holes in the substrate coincident with the sliding of the plurality of first pins, and

after the snapping of the at least one spring clip,

snapping a cover onto the plurality of second pins.

26. The method of claim 24, further comprising:

prior to the sliding of the plurality of first pins into the first plurality of holes of the substrate,

applying a thermal grease between the integrated circuit package and the thermal element.

27. The method of claim 24, wherein,

the plurality of first pins are pressed into the thermal element, and

a shoulder of each of the plurality of first pins limits insertion depth.

28. The method of claim 24, wherein,

the first plurality of pins are screwed into the thermal element, and

a shoulder of each of the plurality of first pins limits insertion depth.

29. The method of claim 24, wherein,

the thermal element includes an integral finned heat sink.

30. The method of claim 24, further comprising:

coupling a heat sink to the thermal element.

31. The method of claim 24, wherein,

the snapping of at least one spring clip includes respectively snapping a first spring clip onto a first pair of the plurality of first pins and snapping a second spring clip onto a second pair of the plurality of first pins.

32. The method of claim 24, wherein,

the snapping of the at least one spring clip includes

inserting a pair of the plurality of first pins into a corresponding pair of slots in the at least one spring clip.

33. The method of claim 32, wherein,

the snapping of at least one spring clip further includes

deflecting bent portions of each of the corresponding pair of slots in the at least one spring clip to exert a pull force and reduce thermal impedance between the thermal element and the integrated circuit package.

34. The method of claim 24, further comprising:

prior to the sliding of the plurality of first pins into the first plurality of holes in the substrate,

coupling a plurality of second pins to the thermal element;

sliding the plurality of second pins coupled to the thermal element through a second plurality of holes in the substrate coincident with the sliding of the first plurality of pins; and

after snapping the at least one spring clip onto the pair of the plurality of first pins,

snapping a cover onto the plurality of second pins to secure the cover over the substrate.

35. The method of claim 34, wherein,

the thermal element includes an integral finned heat sink.

36. The method of claim 34, further comprising:

prior to sliding the plurality of second pins coupled to the thermal element through the second plurality of holes in the substrate coincident with the sliding of the first plurality of pins,

applying a thermal grease between the integrated circuit package and the thermal element.

37. The method of claim 34, wherein,

the plurality of second pins are pressed into the thermal element, and a shoulder of each of the plurality of second pins limits insertion depth.

38. The method of claim 34, wherein,

the plurality of second pins are screwed into the thermal element, and a shoulder of each of the plurality of second pins limits insertion depth.

39. The method of claim 34, wherein,

the snapping of at least one spring clip includes respectively snapping a first spring clip onto a first pair of the plurality of first pins and snapping a second spring clip onto a second pair of the plurality of first pins.

40. The method of claim 34, wherein,

the snapping of the at least one spring clip includes

inserting a pair of the plurality of first pins into a corresponding pair of slots in the at least one spring clip.

41. The method of claim 40, wherein,

the snapping of the at least one spring clip further includes

deflecting bent portions of each of the corresponding pair of slots in the at least one spring clip to exert a pull force and reduce thermal impedance between the thermal element and the integrated circuit package.