Structure for removably attaching a heat sink to surface mount packages

• US 6,219,238 B1
• Filed: 05/10/1999
• Issued: 04/17/2001
• Est. Priority Date: 05/10/1999
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Shaukatullah, Hussain, Andros, Frank E., Storr, Wayne R., Gaynes, Michael A.
• Primary Examiner(s): TOLIN, GERALD P
• Application Number:
  US09/307,890
• Time in Patent Office: 708 Days
• Field of Search: 174/16.3, 165/80.3, 165/185, 267/150, 267/158, 267/160, 244/57, 244/58, 246/25, 248/316.7, 248/505, 248/510, 361/703, 361/704, 361/707, 361/709, 361/712, 361/717-719, 361/720-722, 257/706, 257/707, 257/713, 257/718, 257/719, 257/727
• US Class Current: 361/704
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• 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 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 2224/73265 Layer and wire 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: Y10T 24/45581 having inserted end formed by oppositely biased surface segments

Abstract

A structure for removably attaching a heat sink to an electronic package. At least one heat sink engaging member engages a surface of the heat sink opposite a surface of the heat sink engaging the electronic package. At least two heat sink retaining clips extend from opposite sides of the at least one heat sink engaging member. Each retaining clip includes a first arm for extending past a side of the heat sink and a portion of the electronic package and a second arm extending from the first member for engaging the electronic package.

Claims

1. A structure for removably attaching a heat sink to a packaged electronic part, comprising:

a thermally conductive plate having opposing first and second surfaces, the second surface being mounted on a surface of the packaged electronic part and having at least two free edges extending beyond the surface of the packaged electronic part;

at least one heat sink engaging member engaging a first surface of the heat sink opposite a second surface of the heat sink engaging the first surface of the thermally conductive plate; and

at least two heat sink retaining clips extending from opposite sides of the at least sink engaging member, each retaining clip including a first arm extending past a side of the heat sink and a portion of the thermally conductive plate and a second arm extending from the first arm engaging the second surface of the thermally conductive plate on a separate edge.

2. The structure according to claim 1, wherein the heat sink engaging member includes at least one aperture formed therethrough.

3. The structure according to claim 1, wherein the heat sink engaging member includes a plurality of spaced apart apertures extending along the heat sink engaging member for receiving elements of the heat sink.

4. The structure according to claim 2, wherein the at least two heat sink retaining clips extend along substantially the entire length of two opposite sides of the heat sink engaging member.

5. The structure according to claim 1, further comprising:

at least two heat sink retaining tabs, at least one tab extending from each of at least two opposite sides of the at least one heat sink engaging member, each retaining tab extending past a side surface of the heat sink and a side surface of the thermally conductive plate other than the side surface of the heat sink and the side surface of the thermally conductive plate that the retaining clips extend past, to prevent the at least one heat sink from substantially shifting position in relation to the thermally conductive plate with the contact force exerted by one or more of the retaining tabs against the thermally conductive plate.

6. The structure according to claim 5, further comprising:

a plurality of heat sink retaining tabs extending from each of at least two opposite sides of the at least one heat sink engaging member.

7. The structure according to claim 1, further comprising:

at least two tool receiving members arranged on opposite sides of the structure for receiving a tool for attaching and removing the structure from the packaged electronic part.

8. The structure according to claim 7, wherein each tool receiving member is provided on a retaining clip.

9. The structure according to claim 7, wherein the tool receiving members each comprise an outwardly flared portion of each retaining clip.

10. An electronic package, comprising:

a packaged semiconductor chip;

a heat spreader plate that the packaged semiconductor chip is attached to;

a heat sink;

an attachment structure removably attaching the heat sink to the heat spreader plate, the attachment structure comprising at least one heat sink engaging member engaging a surface of the heat sink opposite a surface of the heat sink engaging the heat spreader plate, and at least two heat sink retaining clips extending from opposite sides of the at least one heat sink engaging member, each retaining clip including a first arm extending past a side of the heat sink and a side of the heat spreader plate and a second arm extending from the first arm engaging the heat spreader plate.

11. A method of removably attaching a heat sink to a packaged electronic part, the method comprising:

arranging the heat sink on a surface of the packaged electronic part;

providing an attachment structure removably attaching the heat sink to a heat spreader plate of the packaged electronic part, the attachment structure comprising at least one heat sink engaging member engaging a surface of the heat sink opposite a surface of the heat sink engaging the heat spreader plate, and at least two heat sink retaining clips extending from opposite sides of the at least one heat sink engaging member, each retaining clip including a first arm extending past a side of the heat sink and a side of the heat spreader plate and a second arm extending from the first arm engaging the heat spreader plate.

12. The method according to claim 11, wherein arranging the attachment structure over the heat sink comprises:

biasing the retaining clips away from each other;

arranging the attachment structure over the heat sink and a portion of the packaged electronic part; and

releasing the retaining clips.

13. The method according to claim 12, wherein biasing the retaining clips away from each other comprises:

engaging at least tool receiving members on the attachment structure with an installation and removal tool; and

causing the tool to bias the retaining clips away from each other.

14. The method according to claim 12, wherein releasing the retaining clips comprises:

causing the tool to release the retaining clips.

15. A method of attaching and removing a heat sink to a packaged electronic part, the method comprising:

arranging the heat sink on a surface of the packaged electronic part;

providing an attachment structure removably attaching the heat sink to a heat spreader plate of the packaged electronic part, the attachment structure comprising at least one heat sink engaging member engaging a surface of the heat sink opposite a surface of the heat sink engaging the heat spreader plate, and at least two heat sink retaining clips extending from opposite sides of the at least one heat sink engaging member, each retaining clip including a first arm extending past a side of the heat sink and a side of the heat spreader plate and a second arm extending from the first arm engaging the heat spreader plate.

detaching the attachment structure from the heat sink and the packaged electronic part.