Low-profile socketed packaging system with land-grid array and thermally conductive slug

• US 5,805,419 A
• Filed: 11/26/1996
• Issued: 09/08/1998
• Est. Priority Date: 05/12/1995
• Status: Expired due to Term

• Current Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: Hundt, Michael J., Chiu, Anthony M.
• Primary Examiner(s): Tolin, Gerald P.
• Application Number:
  US08/756,460
• Time in Patent Office: 651 Days
• Field of Search: 248/505, 248/510, 174/16.3, 174/52.2, 174/52.4, 267/150, 267/160, 24/295, 24/455, 24/457, 24/458, 24/625, 165/80.3, 165/185, 257/706, 257/707, 257/713, 257/727, 257/718-720, 439/485, 439/487, 439/18, 439/86, 439/70-73, 361/761, 361/764, 361/785, 361/787, 361/704-707, 361/709, 361/712, 361/717-719, 361/722
• US Class Current: 361/719
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 23/4093 Snap-on arrangements, e.g. clips
• CPC Class Codes: H01L 24/48 of an individual wire connector
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01087 Francium [Fr]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/207 Diameter ranges
• CPC Class Codes: H05K 7/1069 with spring contact pieces

Abstract

A socketed integrated circuit packaging system, including a packaged integrated circuit and a socket therefor, is disclosed. The integrated circuit package includes a device circuit board to which a thermally conductive slug is mounted; the underside of the device circuit board has a plurality of lands arranged in an array. The integrated circuit chip is mounted to the slug, through a hole in the device circuit board, and is wire-bonded to the device circuit board and thus to the lands on the underside. The socket is a molded frame, having a hole therethrough to receive the conductive slug of the integrated circuit package; the socket may also have its own thermally conductive slug disposed within the hole of the frame. The socket has spring contact members at locations matching the location of the lands on the device circuit board. The integrated circuit package may be inserted into the socket frame, held there by a metal or molded clip. A low profile, low cost, and high thermal conductivity package and socket combination, is thus produced.

Claims

1. An integrated circuit package disposed in a socket, comprising:

an integrated circuit package, comprising;

a first thermally conductive slug;

an integrated circuit chip mounted on said first thermally conductive slug;

a device substrate attached to said first thermally conductive slug, said device substrate having a plurality of plated lands disposed on a bottom surface thereof;

a plurality of electrical connections between said integrated circuit chip and said device substrate, and

a socket comprising;

a frame having a first surface and a second surface, and having an opening therethrough;

a plurality of spring contact elements disposed proximate to the opening in said frame, each of said spring contact elements extending through said frame from said first surface to said second surface, and each of said spring contact elements being held in contact with a corresponding one of said plated lands; and

a releasable holding means holding said integrated circuit package proximate to said frame.

2. The integrated circuit package of claim 1 wherein said releasable holding means is formed integrally with said frame.

3. The integrated circuit package of claim 2 wherein said releasable holding means comprises a plurality of snap lips extending from said first surface of said frame.

4. The integrated circuit package of claim 1 wherein said releasable holding means comprises a spring clip.

5. The integrated circuit package of claim 1 wherein each of said spring contact elements is comprised of a precious metal.

6. The integrated circuit package of claim 1 further comprising a plurality of holes formed through said frame, one of said spring contact elements being disposed in each of said holes.

7. The integrated circuit package of claim 6, further comprising a plurality of protrusions, each protrusion being located within one of said holes and being in contact with a respective one of said spring contact elements to hold said spring contact element in said hole.

8. The integrated circuit package of claim 1 wherein each of said spring contact elements further comprises a dimple extending above said first surface of said frame and being in contact with a corresponding one of said plated lands.

9. The integrated circuit package of claim 1, further comprising:

a second thermally conductive slug disposed within the opening in said frame, said second thermally conductive slug being in contact with said first thermally conductive slug.

10. The integrated circuit package of claim 1, further comprising:

a layer of thermally conductive grease disposed on a bottom side of said first thermally conductive slug;

an encapsulant material disposed over said integrated circuit chip; and

wherein said device substrate is a device circuit board.

11. The integrated circuit package of claim 1 wherein said spring contact elements are comprised of coil springs.

12. An integrated circuit package disposed in a socket, comprising:

an integrated circuit package, comprising;

a thermally conductive slug;

an integrated circuit chip mounted on said thermally conductive slug;

a device substrate attached to said thermally conductive slug, said device substrate having a plurality of plated lands disposed on a bottom surface thereof;

a plurality of electrical connections between said integrated circuit chip and said device substrate; and

a socket comprising;

a frame having a first surface and a second surface, and having an opening therethrough;

a plurality of spring contact elements disposed proximate to the opening in said frame, each of said spring contact elements being held in contact with a corresponding one of said plated lands; and

a releasable holding means holding said integrated circuit package proximate to said frame.

13. The integrated circuit package of claim 12, further comprising:

a layer of thermally conductive grease disposed on a bottom side of said thermally conductive slugs;

an encapsulant material disposed over said integrated circuit chip; and

wherein said device substrate is a device circuit board.

14. The integrated circuit package of claim 12 wherein said spring contact elements are comprised of coil springs.

15. An integrated circuit package disposed in a socket, comprising:

a first thermally conductive slug having a first surface and a second surface;

an integrated circuit chip mounted to the first surface of said first thermally conductive slug;

a device substrate having a bottom surface, said device substrate being fixed to said first thermally conductive slug, the second surface of said first thermally conductive slug extending below the bottom surface of said device substrate;

a plurality of electrical connections between said integrated circuit chip and said device substrate;

a plurality of plated lands disposed on the bottom surface of said device substrate;

a frame;

a plurality of spring contact elements disposed in said frame, each of said spring contact elements extending through said frame; and

a releasable holding means holding said device substrate proximate to said frame, each of said plated lands being in contact with a respective one of said spring contact elements.

16. The integrated circuit package of claim 15, further comprising an opening formed through said frame, said first thermally conductive slug being aligned in the opening of said frame and being received therein.

17. The integrated circuit package of claim 16, further comprising a second thermally conductive slug disposed in the opening of said frame, said second thermally conductive slug being in contact with said first thermally conductive slug.

18. An integrated circuit package mounted on a system substrate, comprising:

a first thermally conductive slug having a first surface and a second surface;

an integrated circuit chip mounted to the first surface of said first thermally conductive slug;

a device substrate having a bottom surface, said device substrate being fixed to said first thermally conductive slug, the second surface of said first thermally conductive slug extending below the bottom surface of said device substrate;

a plurality of electrical connections between said integrated circuit chip and said device substrate;

a plurality of plated lands disposed on the bottom surface of said device substrate;

a frame having a first surface and a second surface, and having a plurality of holes formed therethrough;

a plurality of spring contact elements, each spring contact element being disposed in one of said holes;

a plurality of conductive joints formed on a system substrate, each of said conductive joints being connected to a second end of a respective one of said spring contact elements such that said frame is fixed to said system substrate; and

a releasable holding means holding said device substrate proximate to said frame, each of said plated lands being in contact with a first end of a respective one of said spring contact elements such that a plurality of conductive pathways are formed, each conductive pathway comprising one of said plated lands, one of said spring contact elements, and one of said conductive joints.

19. The integrated circuit package of claim 18, further comprising an opening formed through said frame, said first thermally conductive slug being aligned in the opening of said frame and being received therein.

20. The integrated circuit package of claim 19 wherein said first thermally conductive slug is held in contact with said system substrate, and further comprising a layer of thermally conductive grease being disposed between said first thermally conductive slug and said system substrate.

21. The integrated circuit package of claim 19, further comprising a second thermally conductive slug fixed in the opening in said frame, said second thermally conductive slug being held in contact with said first thermally conductive slug and said system substrate, said second thermally conductive slug being disposed between said first thermally conductive slug and said system substrate.

22. The integrated circuit package of claim 21, further comprising:

a layer of thermally conductive grease interposed between said first thermally conductive slug and said second thermally conductive slug; and

a layer of thermally conductive grease interposed between said second thermally conductive slug and said system substrate.

23. The integrated circuit package of claim 19 wherein said conductive joints are solder joints, the second end of each of said spring contact elements being connected to one of said solder joints with a solder connection, and wherein said device substrate is a device circuit board and said system substrate is a system circuit board.

24. The integrated circuit package of claim 19, further comprising an encapsulant material disposed over said integrated circuit chip.

25. The integrated circuit package of claim 19 wherein each of said holes further comprises a protrusion, each of said spring contact elements being held in a respective one of said holes by one of said protrusions.

26. The integrated circuit package of claim 19 wherein said releasable holding means is formed integrally with said frame.

27. The integrated circuit package of claim 26 wherein said releasable holding means comprises a plurality of opposing snap lips.

28. The integrated circuit package of claim 19 wherein said releasable holding means comprises a spring clip.

29. The integrated circuit package of claim 19 wherein the second end of each of said spring contact elements extends through the second surface of said frame and the first end of each of said spring contact elements extends through the first surface of said frame.

30. The integrated circuit package of claim 19 wherein each spring contact element is comprised of a coil spring.

31. The integrated circuit package of claim 19 wherein each of the spring contact elements is comprised of a precious metal and the first end of each of said spring contact elements is formed in the shape of a dimple.