Brazed wick for a heat transfer device and method of making same

• US 20050205243A1
• Filed: 05/02/2005
• Published: 09/22/2005
• Est. Priority Date: 06/26/2003
• Status: Abandoned Application

• Current Assignee: John H. Rosenfeld, Kenneth G. Minnerly
• Original Assignee: John H. Rosenfeld, Kenneth G. Minnerly
• Inventors: Rosenfeld, John H., Minnerly, Kenneth G.
• Application Number:
  US11/120,238
• Publication Number:
  US 20050205243A1
• Time in Patent Office: Days
• US Class Current: 165/104.260
• CPC Class Codes: B22F 2201/013 Hydrogen
• CPC Class Codes: B22F 2201/20 Use of vacuum
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 3/1103 with particular physical characteristics
• 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 2275/04 by brazing brazing heat exchangers B23K1/0012
• 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: Y10T 29/49353 Heat pipe device making

Abstract

A capillary structure for a heat transfer device, such as a heat pipe is provided having a plurality of particles joined together by a brazing compound such that fillets of the brazing compound are formed between adjacent ones of the plurality of particles. In this way, a network of capillary passageways are formed between the particles to aid in the transfer of working fluid by capillary action, while the plurality of fillets provide enhanced thermal transfer properties between the plurality of particles so as to greatly improve over all heat transfer efficiency of the device. A method of making the capillary structure according to the invention is also presented.

Claims

1. A capillary structure for a heat transfer device comprising:

a plurality of particles joined together by a brazing compound such that fillets of said brazing compound are formed between adjacent ones of said plurality of particles so as to form a network of capillary passageways between said particles.

2. A capillary structure according to claim 1 wherein said plurality of particles comprise a first melting temperature and said brazing compound comprises a second melting temperature that is lower than said first melting temperature.

4. A capillary structure according to claim 1 wherein said fillets are formed by capillary action of said braze compound when in a molten state.

5. A capillary structure according to claim 1 wherein said particles are selected from the group consisting of carbon, tungsten, copper, aluminum, magnesium, nickel, gold, silver, aluminum oxide, and beryllium oxide.

6. A capillary structure according to claim 1 wherein said particles comprise a shape selected from the group consisting of spherical, oblate spheroid, prolate spheroid, ellipsoid, polygonal, and filament.

7. A capillary structure according to claim 1 wherein said particles comprise at least one of copper spheres and oblate copper spheroids having a melting point of about one thousand eighty-three °

C.

12. A capillary structure according to claim 2 wherein metal particles are a constituent portion of said braze compound prior to reaching said second melting temperature and comprise a smaller size than said plurality of particles.

13. A capillary structure according to claim 1 wherein said braze compound is selected from the group consisting of nickel-based Nicrobrazes, silver/copper brazes, tin/silver, lead/tin, and polymers.

14. A capillary structure according to claim 1 wherein said plurality of particles comprise aluminum and magnesium and said brazing compound comprises an aluminum/magnesium intermetallic alloy.

21. A heat pipe according to claim 14 wherein said particles comprise at least one of copper spheres and oblate copper spheroids having a melting point of about 1083°

C.

3. (canceled)

8-11. -11. (canceled)

15. A heat pipe comprising:

a hermetically sealed and partially evacuated enclosure, said enclosure comprising internal surfaces;

a wick disposed on at least one of said internal surfaces and comprising a plurality of particles joined together by a brazing compound such that fillets of said brazing compound are formed between adjacent ones of said plurality of particles so as to form a network of capillary passageways between said particles; and

a two-phase fluid at least partially disposed within a portion of said wick.

16. A heat pipe according to claim 15 wherein said plurality of particles comprise a first melting temperature and said brazing compound comprises a second melting temperature that is lower than said first melting temperature.

18. A heat pipe according to claim 15 wherein said fillets are formed by capillary action of said braze compound when in a molten state.

19. A heat pipe according to claim 15 wherein said particles are selected from the group consisting of carbon, tungsten, copper, aluminum, magnesium, nickel, gold, silver, aluminum oxide, and beryllium oxide.

20. A heat pipe according to claim 15 wherein said particles comprise a shape selected from the group consisting of spherical, oblate spheroid, prolate spheroid, polygonal, and filament.

23. A heat pipe according to claim 16 wherein said brazing compound is present in the range from about two percent to about ten percent.

24. A heat pipe according to claim 16 wherein said particles comprise copper powder comprising particles size in a range from about twenty mesh to about two-hundred mesh.

25. A heat pipe according to claim 16 wherein said braze compound comprises particles that comprise about minus three hundred and twenty-five mesh prior to melting.

26. A heat pipe according to claim 16 wherein particles are a constituent portion of said braze compound prior to reaching said second melting temperature and comprise a smaller size than said plurality of particles.

27. A heat pipe according to claim 16 wherein said braze compound is selected from the group consisting of nickel-based Nicrobrazes, silver/copper brazes, tin/silver, lead/tin, and polymers.

28. A heat pipe according to claim 16 wherein said plurality of particles comprise aluminum and magnesium and said brazing compound comprises an aluminum/magnesium intermetallic alloy.

17. (canceled)

22. (canceled)

29-43. -43. (canceled)

44. A heat pipe comprising:

a sealed and partially evacuated enclosure having an internal surface;

a grooved brazed wick disposed upon said internal surface comprising a plurality of individual particles and a brazing compound such that fillets of said brazing compound are formed between adjacent ones of said plurality of particles, and further including at least two lands that are in fluid communication with one another wherein said particles are thermally engaged with one another by a plurality of said fillets; and

a working fluid disposed within said enclosure.

45-58. -58. (canceled)