FLATTENED HEAT PIPE AND MANUFACTURING METHOD THEREOF

• US 20120118537A1
• Filed: 01/20/2012
• Published: 05/17/2012
• Est. Priority Date: 07/21/2009
• Status: Active Grant

• Current Assignee: Furukawa Electric Company Limited
• Original Assignee: Furukawa Electric Company Limited
• Inventors: Sasaki, Yasumi, Okada, Hiroshi, Furumoto, Shinichi, Yamamoto, Masaaki, KAMEOKA, Hideaki, Sugimura, Masanobu, Miura, Tatsuro
• Granted Patent: US 9,188,396 B2
• Time in Patent Office: Days
• US Class Current: 165/104.26
• 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 15/04 with tubes having a capillary structure
• CPC Class Codes: F28D 15/046 characterised by the material or the construction of the capillary structure
• 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

The invention provides a flattened heat pipe whose vapor flowing passage is not clogged and which has an excellent capillary force. The flattened heat pipe has a closed container formed by flattening a tubular container, a plurality of wick structures arrayed within the container in a longitudinal direction so as to form an acute-angled portion where a capillary force is large at least partially within the container, a hollow portion formed of an outer peripheral surface of the wick structure and an inner wall surface of the container and a working fluid sealed into the container.

Claims

1. A flattened heat pipe, comprising:

a flat and tubular closed container;

at least one wick structure; and

a working fluid sealed into the container, wherein

the wick structure consists of a sintered metal formed of sintered globular or deformed powder,

a cross-sectional shape of the wick structure in the container is formed into a semi-elliptical shape having a curved portion and a flat portion,

the flat portion of the wick structure is in contact with an inner wall of the container,

the curved portion of the wick structure is in contact with or in close proximity to the inner wall of the container by leaving a gap less than a predetermined distance,

a capillary force is generated between the curved portion and the inner wall, while a capillary force is also generated in voids formed in the sintered metal, and

vapor flowing passages are formed at least in curved areas of both sides of the container.

2. The flattened heat pipe according to claim 1, wherein the wick structure is formed of a substantially same thickness as a whole.

3. The flattened heat pipe according to claim 1, wherein a thickness of the wick structure is changed so as to be thicker in a high-temperature portion where an exothermic element is disposed than in a low-temperature portion where none of exothermic elements are disposed.

4. The flattened heat pipe according to claim 1, wherein a thickness of the container is changed so as to be thinner in a high-temperature portion where an exothermic element is disposed than in a low-temperature portion where none of exothermic elements are disposed.

5. The flattened heat pipe according to claim 1, wherein a distance from an apex of the curved portion of the wick structure to the inner wall of the container is equal to 1.0 mm or less than 1.0 mm.

6. The flattened heat pipe according to claim 2, wherein a distance from an apex of the curved portion of the wick structure to the inner wall of the container is equal to 1.0 mm or less than 1.0 mm.

7. The flattened heat pipe according to claim 1, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

8. The flattened heat pipe according to claim 2, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

9. The flattened heat pipe according to claim 3, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

10. The flattened heat pipe according to claim 4, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

11. The flattened heat pipe according to claim 5, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

12. The flattened heat pipe according to claim 6, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

13. A flattened heat pipe, comprising:

a flat and tubular closed container;

a plurality of wick structures; and

a working fluid sealed into the container, wherein

the wick structures consist of sintered metals formed of sintered globular or deformed powder,

cross-sectional shapes of the wick structures in the container are respectively formed into semi-elliptical shapes having curved portions and flat portions,

the flat portions of the wick structures are in contact with an inner wall of the container,

the curved portions of neighboring wick structures are in contact with or in close proximity to each other by leaving a gap less than a predetermined distance,

a capillary force is generated between neighboring curved portions, while a capillary force is also generated in voids formed in the sintered metals, and

vapor flowing passages are formed at least in curved areas of both sides of the container.

14. The flattened heat pipe according to claim 13, wherein the wick structure is formed of a substantially same thickness as a whole.

15. The flattened heat pipe according to claim 13, wherein a thickness of the wick structure is changed so as to be thicker in a high-temperature portion where an exothermic element is disposed than in a low-temperature portion where none of exothermic elements are disposed.

16. The flattened heat pipe according to claim 13, wherein a thickness of the container is changed so as to be thinner in a high-temperature portion where an exothermic element is disposed than in a low-temperature portion where none of exothermic elements are disposed.

17. The flattened heat pipe according to claim 13, wherein a distance between neighboring curved portions of the wick structures is equal to 1.0 mm or less than 1.0 mm.

18. The flattened heat pipe according to claim 14, wherein a distance between neighboring curved portions of the wick structures is equal to 1.0 mm or less than 1.0 mm.

19. The flattened heat pipe according to claim 17, wherein the plurality of wick structures are disposed respectively on parts opposite each other of the inner wall of the container.

20. The flattened heat pipe according to claim 18, wherein the plurality of wick structures are disposed respectively on parts opposite each other of the inner wall of the container.

21. The flattened heat pipe according to claim 13, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

22. The flattened heat pipe according to claim 14, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

23. The flattened heat pipe according to claim 15, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

24. The flattened heat pipe according to claim 16, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

25. The flattened heat pipe according to claim 17, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

26. The flattened heat pipe according to claim 18, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

27. The flattened heat pipe according to claim 19, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

28. The flattened heat pipe according to claim 20, wherein a concavo-convex portion is formed on the inner wall in a longitudinal direction of the container and the container itself creates a capillary force.

29. A manufacturing method of a flattened heat pipe, comprising steps of:

inserting a core rod, having a cross sectional shape in which one part is cut from a substantially circular shape so as to form a flat cutaway portion, into a tubular contoured object of which one end is concealed or having a narrower diameter;

filling metal powder into a space formed by the cutaway portion and an inner wall of the tubular contoured object;

heating the tubular contoured object in a state in which the core rod is inserted to prepare a sintered metal in contact with the inner wall;

pulling the core rod out of the tubular contoured object; and

pressing and deforming the tubular contoured object to form a deformed container so that the sintered metal is in contact with the inner wall or in close proximity to the inner wall with a gap less than a predetermined distance.

30. The manufacturing method of the flattened heat pipe according to claim 29, wherein the core rod has a substantially same cross-sectional shape from one end of the core rod to another end of the core rod.

31. The manufacturing method of the flattened heat pipe according to claim 29, wherein the flat cutaway portion is smaller in one end of the core than in another end of the core rod.

32. A manufacturing method of a flattened heat pipe, comprising steps of:

inserting a core rod, having a cross sectional shape in which a plurality of parts are cut from a substantially circular shape so as to form flat cutaway portions, into a tubular contoured object of which one end is concealed or having a narrower diameter;

filling metal powder into spaces formed by the cutaway portions and an inner wall of the tubular contoured object;

heating the tubular contoured object in a state in which the core rod is inserted to prepare sintered metals in contact with the inner wall;

pulling the core rod out of the tubular contoured object; and

pressing and deforming the tubular contoured object to form a deformed container so that the sintered metals are in contact with each other or in close proximity to each other with a gap less than a predetermined distance.

33. The manufacturing method of the flattened heat pipe according to claim 32, wherein the core rod has a substantially same cross-sectional shape from one end of the core rod to another end of the core rod.

34. The manufacturing method of the flattened heat pipe according to claim 32, wherein the flat cutaway portion is smaller in one end of the core than in another end of the core rod.