Composite heat sink

• US 6,062,302 A
• Filed: 09/30/1997
• Issued: 05/16/2000
• Est. Priority Date: 09/30/1997
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Gossett, Keith Alan, Davis, Dwight Maclaren
• Primary Examiner(s): ATKINSON, CHRISTOPHER MARK
• Application Number:
  US08/940,754
• Time in Patent Office: 959 Days
• Field of Search: 361/700, 257/715, 165/104.26, 165/104.21, 165/104.33, 165/185, 174/15.2
• US Class Current: 165/104.26
• CPC Class Codes: F28D 15/02 in which the medium condenses and evaporates, e.g. heat pipes heat pipes used in solar heat collectors F24S10/95; in radiators F28D1/0226; in nuclear reactors G21C15/257
• 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 15/046 characterised by the material or the construction of the capillary structure
• CPC Class Codes: F28F 3/02 Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations F28F3/08 takes precedence
• 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
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]

Abstract

The present invention is a heat sink with a heat transfer medium for enhancing the heat transferring ability of the heat sink. In one embodiment, the heat sink comprises a plurality of fins with cavities, a base and a fluid heat transfer medium. The fins are in thermal contact with the base and configured to form a series of longitudinal channels through which air or a fluid medium may pass. The fluid heat transfer medium contained within each of the cavities. The fluid heat transfer medium enhances the heat sink'"'"'s ability to transfer heat without increasing its surface area, size and/or weight. This enhancement is due to the fluid heat transfer medium'"'"'s latent heat of vaporization and condensation. Specifically, a larger amount energy is required to vaporize the fluid heat transfer medium. Thus, a large amount of heat can be conducted from the base to the fluid heat transfer medium. Conversely, as the vaporized fluid heat transfer medium condenses on the upper cooler walls of the fins, a large amount of energy is conducted from the vaporized fluid heat transfer medium to the fins. Thus, a larger amount of heat can be conducted from the fluid heat transfer medium to the fins which can then dissipate the heat to lower temperature surroundings.

Claims

1. A heat sink comprising:

a plurality of fins having a plurality of cavities, each fin having one internal cavity and one orifice, each cavity of each fin being isolated from any cavity of any other fin;

a base coupled to the plurality of fins, wherein each cavity does not extend into the base;

a heat transfer medium contained within said cavities and in thermal contact with said base; and

a plurality of seal plugs for sealing the orifices.

2. The heat sink of claim 1, wherein said heat transfer medium is a conductive heat transfer medium.

3. The heat sink of claim 1, wherein said heat transfer medium is a fluid that possess a thermal resistant and a boiling point lower than thermal resistants and softening points of said base and said plurality of fins.

4. The heat sink of claim 3 further comprising:

a porous wick contained within said cavities.

5. The heat sink of claim 1, wherein said heat transfer medium comprises water.

6. The heat sink of claim 1, wherein said heat transfer medium comprises alcohol.

7. The heat sink of claim 1, wherein said heat transfer medium comprises a thermal conductive material that possess a thermal resistant lower than a thermal resistant of said base and said plurality of fins.

8. The heat sink of claim 1, wherein said plurality of fins are configured to form longitudinal channels.

9. The heat sink of claim 1, wherein each of said plurality of fins are constructed from a thermal conductive material.

10. The heat sink of claim 1, wherein said base is constructed from a thermal conductive material.

11. A heat sink comprising:

a plurality of fins having a plurality of cavities, each fin having one internal cavity and one orifice, each cavity of each fin being isolated from any cavity of any other fin;

a base coupled to the plurality of fins, wherein each cavity does not extend into the base; and

a solid heat transfer medium contained within said cavities and in thermal contact with said base, the solid heat transfer medium possessing a thermal resistant lower than thermal resistants of said base and said plurality of fins.