Heat sink assembly for solid state devices

• US 5,313,099 A
• Filed: 03/04/1993
• Issued: 05/17/1994
• Est. Priority Date: 03/04/1993
• Status: Expired due to Term

• Current Assignee: Tyco Electronics Logistics AG (TE Connectivity Limited)
• Original Assignee: Square Head Incorporated
• Inventors: Tata, Peter D., Rife, William B.
• Primary Examiner(s): Jackson, Jerome
• Assistant Examiner(s): Arroyo, T. M.
• Application Number:
  US08/026,515
• Time in Patent Office: 439 Days
• Field of Search: 257/706, 257/684, 257/718, 257/719, 257/727, 257/717
• US Class Current: 257/717
• CPC Class Codes: H01L 2023/405 heatsink to package
• CPC Class Codes: H01L 2023/4087 Mounting accessories, interposers, clamping or screwing parts
• CPC Class Codes: H01L 23/4006 with bolts or screws
• 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 assembly adapted for use with an electronic device package such as a microprocessor having a grid array is shown having, in a first embodiment, a threaded base of a finned heat sink adapted to be received in a threaded bore of an adaptor which mounts onto the electronic device package. Desired thermal coupling is achieved by screwing down the heat sink in biasing engagement with the package. An alternate embodiment shows the heat sink which has a snap on flange to attach the heat sink to the adaptor.

Claims

1. A heat sink assembly for removing heat from an electronic device package comprising

an adaptor having a top wall and having a pair of opposed side walls depending downwardly therefrom, a groove formed in each side wall extending generally parallel to the top wall in alignment with and facing each other and being capable of slidably receiving said electronic device package, first and second planes lying respectively in the top and bottom of the grooves defining a space therebetween, the groove being adapted to clampingly receive opposite marginal portions of an electronic device package when inserted therein, a bore centrally located in the top wall and extending therethrough,

a heat sink member having a cylindrical base member with a flat bottom surface adapted to be received through the bore in the top wall, the base member formed with means to engage with the periphery of the bore to secure and to attach the heat sink member to the adaptor with the flat bottom surface disposed in the space between the first and second planes whereby an electronic device package slidably inserted in the grooves will cause the top wall to bow through engagement with the flat bottom surface of the base.

2. A heat sink assembly according to claim 1 in which the means to attach the heat sink member to the adaptor comprises a circular flange extending radially outwardly from the base member, the flange having a diameter slightly larger than the bore in the top wall and having a tapered edge portion to facilitate insertion of the base member through the bore and to serve as a cam surface to force the base upwardly and concomitantly the top wall to bow when an electronic device package is inserted in the grooves;

said base member being in communication with the periphery of said bore to secure said base member to the adaptor.

3. A heat sink assembly according to claim 1 in which the means to attach the heat sink member to the adaptor comprises a male thread formed on the base member and a female thread formed in the bore of the top wall to directly threadably receive the base member.

4. A heat sink assembly according to claim 1 including a stop surface depending downwardly from the top wall to limit the sliding travel in a direction perpendicular to the longitudinal axis of said base member of an electronic device package inserted in the grooves.

5. A heat sink assembly according to claim 1 in which the heat sink comprises a plurality of generally circular fin members spaced along a generally cylindrical core and extending radially therefrom.

6. A heat sink assembly according to claim 3 in which the plane extending through the bottom of the grooves is a selected distance from the upper surface of the top wall and the thread formed on the cylindrical base member extends for a distance along the longitudinal axis of the base member a distance less than the selected distance to prevent excessive forces from being exerted on the electronic device package.

7. A heat sink assembly according to claim 3 in which the top wall is formed with a boss portion having a greater thickness than the remainder of the top wall, the threaded bore extending through the boss portion to threadably receive said base member to enable said base member to extend slightly below said top wall to provide frictional communication with said electronic device package.

12. A heat sink assembly according to claim 1 in which the heat sink comprises a continuous helically shaped fin member extending radially outwardly from a core.

14. A heat sink assembly according to claim 1 in which the side walls have a lower distal end portion formed with a tapered surface so that the adaptor can be pushed downwardly onto an electronic device package with the tapered surfaces camming the side walls apart to allow the electronic device package to pass by the tapered surface;

said adaptor being capable of being pushed downwardly onto an electronic device package when the heat sink member is not threaded into the bore in the top wall and when said heat sink member is partially threaded into said bore to provide pressure onto the top surface of the electronic device package to secure the assembly to the electronic device package.

8. A heat sink assembly for removing heat from an electronic device package having an outer peripheral edge and an array of pins comprising

an adaptor having a top wall and having a pair of opposed side walls depending therefrom, each side wall having a distal end portion and having an inwardly laterally extending lip, forming a groove adapted to receive between each lip and the top wall the marginal portions of an electronic device package inserted therein, a threaded bore formed through the top wall, each of said lips extend inward a distance less than the distance from the outer edge of said electronic device package to said pins;

and

a heat sink member having a threaded base portion with a substantially flat bottom surface adapted to be threadably received in the threaded bore in the top wall whereby the base of the heat sink can be screwed down through the bore in the top wall with a flat bottom surface in engagement with a top surface of the electronic device package received in the adaptor.

9. A heat sink assembly according to claim 8 in which the top wall of the adaptor has a selected thickness and the threaded base portion has a longitudinal axis, the threaded base portion of the heat sink having a length taken along the longitudinal axis greater than the selected thickness to enable it, upon being screwed down, to exert sufficient pressure on the top surface of the electronic device to secure the assembly on the electronic device package.

10. A heat sink assembly according to claim 8 in which the heat sink comprises a plurality of generally circular fin members spaced along a generally cylindrical core and extending radially therefrom.

11. A heat sink assembly according to claim 8 in which the adaptor has a stop surface to limit sliding motion in a direction perpendicular to the longitudinal axis of said base portion of an electronic device package inserted into the adaptor.

13. A heat sink assembly according to claim 8 in which the heat sink comprises a continuous helically shaped fin member extending radially outwardly from a core.

15. A heat sink assembly according to claim 8 in which a tapered surface is formed on the distal end portions of the side walls so that the adaptor can be pushed downwardly onto an electronic device package with the tapered surfaces camming the side walls apart to allow the electronic device package to pass by the tapered surface;

said adaptor being capable of being pushed downwardly onto an electronic device package when the heat sink member is not threaded into the bore in the top wall and when said heat sink member is partially threaded into said bore to provide pressure onto the top surface of the electronic device package to secure the assembly to the electronic device package.

16. A heat sink assembly for removing heat from an electronic device package comprising

an adaptor having a top wall and having a pair of opposed side walls depending downwardly therefrom to a lower distal end portion, a lip extending laterally inwardly from each lower distal end portion aligned with and facing each other, an aperture formed in the top wall extending therethrough, said adaptor being capable of slidably receiving the electronic device package;

a heat sink member having a base member with a flat bottom surface adapted to be received through the aperture in the top wall, the base member formed with means to directly engage the periphery of the aperture to secure and to attach the heat sink member to the adaptor with the flat bottom surface disposed below the top wall whereby an electronic device package held between the side walls above the lips will be disposed in heat transfer relation with the heat sink member.

17. A heat sink assembly according to claim 16 in which the base member and the aperture are generally cylindrical and the means to attach the heat sink member to the adaptor comprises a male thread formed on the base member and a female thread formed in the aperture in the top wall to threadably receive the base member.

18. A heat sink assembly according to claim 16 in which the means to attach the heat sink member to the adaptor comprises a flange extending outwardly from the base member, the flange having an outer configuration shaped to correspond to that of the aperture but being slightly larger than the aperture and having a tapered edge portion to facilitate insertion of the base member through the aperture;

whereby the base member is attached to the periphery of said aperture to secure the base member to the adaptor.

19. A heat sink assembly according to claim 16 in which the lips on the lower distal end portions of the side walls are formed with a tapered surface so that the adaptor can be pushed downwardly onto an electronic device package with the tapered surfaces camming the side walls apart to allow the electronic device package to pass by the lips;

and adaptor being capable of being pushed downwardly onto an electronic device package when the heat sink member is not threaded into the bore in the top wall and when said heat sink member is partially threaded into said bore to provide pressure onto the top surface of the electronic device package to secure the assembly to the electronic device package.