Heat pipe and process for manufacturing the same

• US 5,694,295 A
• Filed: 04/26/1996
• Issued: 12/02/1997
• Est. Priority Date: 05/30/1995
• Status: Expired due to Term

• Current Assignee: Fujikura Limited
• Original Assignee: Fujikura Limited
• Inventors: Ono, Motoyuki, Hasegawa, Masashi, Saito, Yuji, Mochizuki, Masataka, Nagata, Masakatsu, Mashiko, Koichi
• Primary Examiner(s): Thompson, Gregory D.
• Application Number:
  US08/638,537
• Time in Patent Office: 585 Days
• Field of Search: 62/259.2, 165/80.2-80.4, 165/104.21, 165/104.22, 165/104.26, 165/104.27, 165/104.33, 174/15.2, 257/714, 257/715, 361/698, 361/699-704, 361/717-718, 361/722
• US Class Current: 361/699
• 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 15/0283 Means for filling or sealing heat pipes
• CPC Class Codes: F28F 13/06 by affecting the pattern of flow of the heat-exchange media F28F13/003 takes precedence; static flow control means in header boxes F28F9/026
• 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: F28F 3/022 the means being wires or pins

Abstract

A heat pipe for transferring heat as the latent heat of evaporation to a radiating portion at a lower temperature by heating a heating portion of a container to evaporate a working fluid and by conveying the produced vapor to the radiating portion thereby to condense the vapor. The container is formed into a flattened hollow shape by: a flat heating portion; a radiating portion opposed at a distance to the heating portion and having a larger area than that of the heating portion; and side wall portions jointing the heating portion and the radiating portion to each other along the entire peripheral edge portions of the same.

Claims

1. A heat pipe for a working fluid to transfer heat in the form of latent heat of evaporation, comprising a flattened hollow container formed generally into a hollow frustum of a quadrangular pyramid and confining said working fluid, wherein said container includes:

a flat heating portion;

a flat radiating portion opposed at a distance to said heating portion and having a larger area than that of said heating portion; and

side wall portions joining said heating portion and said radiating portion to each other, said side wall portions being tapered along substantially the entire height thereof.

2. A heat pipe according to claim 1,

wherein said heating portion is made to have the same shape as that of the surface of a heating member and held in close contact with said heating member.

3. A heat pipe according to claim 1, further comprising a heat sink having a base plate provided with a multiplicity of radiating projections and mounted on said radiating portion.

4. A heat pipe according to claim 3, wherein said radiating projections fins of thin sheet.

5. A heat pipe according to claim 4, further comprising plates mounted between said fins for controlling the flow direction of air between said fins.

6. A heat pipe according to claim 3, wherein said radiating projections have pins.

7. A heat pipe according to claim 3, further comprising a holder for holding and mounting said container and said heat sink on a circuit board.

8. A heat pipe according to claim 1, further comprising a multiplicity of projections formed on the inner face of said heating portion and the inner face of said radiating portion.

9. A heat pipe according to claim 8, wherein the projections on the inner face of said heating portion have sintered balls.

10. A heat pipe according to claim 8, wherein the projections on the inner face of said radiating portion have ribs formed between grooves.

11. The heat pipe of claim 1 wherein said flat radiating portion opposed at a distance to said heating portion has an area at least four times that of said heating portion.

12. The heat pipe of claim 11 including heat radiating fins mounted exteriorly of said heat pipe and substantially only on said radiating portion opposed at a distance to said heating portion.

13. A heat pipe for a working fluid to transfer heat in the form of latent heat of evaporation, comprising a flattened hollow container confining said working fluid, wherein said container includes:

a flat heating portion;

a flat radiating portion opposed at a distance to said heating portion and having a larger area than that of said heating portion;

side wall portions joining said heating portion and said radiating portion to each other, said side wall portions being tapered along substantially the entire height thereof; and

heat radiating fins mounted exteriorly of said heat pipe and substantially only on said radiating portion opposed at a distance to said heating portion.

14. A heat pipe for a working fluid to transfer heat in the form of latent heat of evaporation, comprising a flattened hollow container confining said working fluid, wherein said container includes:

a flat heating portion;

a flat radiating portion opposed at a distance to said heating portion and having an area at least four times that of said heating portion; and

side wall portions joining said heating portion and said radiating portion to each other, said side wall portions being tapered along substantially the entire height thereof.