Heatsink with embedded heat pipe for thermal management of CPU

• US 6,424,528 B1
• Filed: 06/20/1997
• Issued: 07/23/2002
• Est. Priority Date: 06/20/1997
• Status: Expired due to Term

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Chao, Shun-lung
• Primary Examiner(s): TOLIN, GERALD P
• Application Number:
  US08/879,592
• Time in Patent Office: 1,859 Days
• Field of Search: 361/687, 361/699, 361/700, 361/702, 361/703, 361/717-719, 174/15.2, 165/80.3, 165/80.4, 165/104.33, 622/592, 257/714, 257/715, 257/722
• US Class Current: 361/700
• CPC Class Codes: F28D 15/0233 the conduits having a particular shape, e.g. non-circular cross-section, annular F28D15/0241, F28D15/0266 take precedence
• CPC Class Codes: F28D 15/0275 Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores
• CPC Class Codes: H01L 23/427 Cooling by change of state, e.g. use of heat pipes by liquefied gas H01L23/445
• 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 heatsink for dissipating thermal energy generated by a microprocessor and neighboring peripheral components. The heatsink is affixed to a printed circuit board within a computer housing. The heatsink includes a thermally conductive base, a plurality of thermally conductive fins, and a heat pipe. The thermally conductive base includes substantially planar upper and lower surfaces displaced from each other by a thickness of the base. The base defines a first channel, proximal to the lower surface, extending from a first end of the base to a second end. The plurality of conductive fins extends substantially perpendicularly from the upper surface of the base. Each of the plurality of fins includes substantially planar proximal and distal major surfaces displaced from each other by a thickness of the fin. The heat pipe is contained within the first channel. The heat pipe includes an elongated casing containing a heat transfer medium and a wick. The wick is immersed in the medium extending along a major access of the heat pipe. The heatsink is configured to be affixed to the printed circuit board with the heat pipe aligned over the center of the microprocessor and the lower surface of the heatsink in close proximity with an upper surface of the microprocessor.

Claims

1. A heatsink for dissipating thermal energy generated by an integrated circuit, said heatsink comprising:

a thermally conductive base including a substantially planar lower surface for abutting against the integrated circuit, wherein said base defines a first channel, proximal to said lower surface extending from a first side of said base to a second side of said base;

a plurality of thermally conductive fins extending from an opposite upper surface of said base; and

a heat pipe contained within said first channel, wherein said heat pipe comprises an elongated casing containing a heat transfer-medium and a wick immersed in said medium and extending along a major axis of said heat pipe, and wherein one end of said heat pipe terminates within said base proximate to the first side and a second end of said heat pipe terminates within said base proximate to the second side.

2. The heatsink of claim 1, wherein said thermally conductive base comprises a material selected from the group comprising aluminum, copper, silver, tungsten and appropriate alloys thereof.

3. The heatsink of claim 1, wherein said base is substantially rectangular and wherein a thickness of said base is in the range of approximately 2 to 20 mm.

4. The heatsink of claim 3, wherein a length of said base is in the range of approximately 100 to 155 mm.

5. The heatsink of claim 3, wherein a width of said base is in the range of approximately 50 to 100 mm.

6. The heatsink of claim 1, wherein each of said plurality of thermally conductive fins is similarly sized and wherein each of said major surfaces is substantially rectangular.

7. The heatsink of claim 6, wherein said plurality of fins are arranged upon said base upper surface in a fin array comprised of a plurality of rows and columns, wherein said major surfaces of said fins are oriented perpendicular to a direction of said columns.

8. The heatsink of claim 7, wherein a height above said base upper surface to which said fins extend is greater than a gap between adjacent rows within said array by a factor in the range of approximately 10 to 20.

9. The heatsink of claim 8, wherein said height is in the range of approximately 30 to 40 mm and said gap between adjacent rows is in the range of approximately 1.5 to 4.0 mm.

10. The heatsink of claim 1, wherein said plurality of fins are integral with said conductive base.

11. The heatsink of claim 1, wherein said heat pipe casing comprises a material selected from the group consisting of copper and aluminum.

12. The heatsink of claim 1, wherein said heat pipe casing is substantially rectangular in cross section and wherein said first channel comprises a rectangularly shaped trench formed into said lower surface of said conductive base.

13. The heatsink of claim 1, wherein said heat pipe casing is substantially circular in cross section and further wherein said first channel comprises a circular tunnel.

14. The heatsink of claim 1, wherein said the pipe medium comprises a fluid selected from the group consisting of water, acetone, methanol, and ethanol.

15. The heatsink of claim 1, wherein said conductive base further defines a second channel, said second channel extending substantially perpendicularly to said first channel and wherein said heatsink further includes a second heat pipe contained within said second channel.

16. The heatsink of claim 15, wherein said conductive base further defines first and second diagonal channels, said diagonal channels extending between respective corners of said base and wherein said heatsink further includes first and second diagonal heat pipes contained respectively within said first and second diagonal channels.

17. The heatsink of claim 1, wherein said heatsink is configured to be affixed to a printed circuit board with said heat pipe aligned over a center of said integrated circuit and said lower surface of said heatsink in close proximity with an upper surface of said integrated circuit.

18. A motherboard for use in a computing system, said motherboard comprising:

a printed circuit board;

a central processing unit affixed to said printed circuit board;

at least one random access memory device affixed to said circuit board and interfaced to said central processing unit; and

a heatsink according to the heatsink of claim 1, wherein said heatsink is affixed to said printed circuit board with said heat pipe aligned over a center of said central processing unit and said lower surface of said heatsink in close proximity with an upper surface of said central processing unit.