Integrated circuit heat pipe heat spreader with through mounting holes

• US 20050217826A1
• Filed: 05/13/2005
• Published: 10/06/2005
• Est. Priority Date: 05/12/1999
• Status: Abandoned Application

• Current Assignee: Aavid Thermalloy LLC (LTI Flexible Products Inc.)
• Original Assignee: Aavid Thermalloy LLC (LTI Flexible Products Inc.)
• Inventors: Rosenfeld, John H., Dussinger, Peter M., Myers, Thomas L., Minnerly, Kenneth L.
• Application Number:
  US11/128,453
• Publication Number:
  US 20050217826A1
• Time in Patent Office: Days
• US Class Current: 165/104.260
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/1035 Liquid phase sintering
• CPC Class Codes: B22F 3/11 Making porous workpieces or articles
• 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 23/4006 with bolts or screws
• 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 heat pipe with superior heat transfer between the heat pipe and the heat source and heat sink is provided. The heat pipe is held tightly against the heat source by mounting holes which penetrate the structure of the heat pipe but are sealed off from the vapor chamber because they each are located within a sealed structure such as a pillar or the solid layers of the casing surrounding the vapor chamber. Another feature of the heat pipe is the use of 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 so as to form a network of capillary passageways between the particles of the wick.

Claims

1-41. -41. (canceled)

42. A heat pipe for spreading heat comprising:

a boundary structure including spaced-apart first and second plates that define an enclosed vapor chamber having a capillary structure 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;

at least one opening defined by a surrounding portion of said first plate which is bonded to said second plate so that said opening is isolated from said vapor chamber.

43. A heat pipe for spreading heat according to claim 42 comprising at least one spacer positioned within said vapor chamber and extending between and contacting said first and second plates.

44. A heat pipe for spreading heat according to claim 42 wherein said spaced-apart first and second plates include confronting interior surfaces;

and

a wick positioned upon said confronting interior surfaces including that portion of the interior surface of said first plate that forms said surrounding portion.

45. A heat pipe for spreading heat according to claim 44 wherein said wick is constructed with at least two separate sections of different materials, with one section being located on said first plate interior surface and being formed of a material with higher heat conductivity than sections located on said second plate interior surface.

46. A heat pipe for spreading heat according to claim 42 wherein said first and second plates each include a peripheral lip located at an edge of said boundary structure which are bonded together.

47. A heat pipe for spreading heat according to claim 42 wherein said brazing compound comprises about sixty-five percent weight copper and thirty-five percent weight gold particles such that said fillets of said brazing compound are formed between adjacent ones of said plurality of particles so as to create a network of capillary passageways between said particles.

48. A heat pipe for spreading heat according to claim 42 wherein said fillets are formed by capillary action of said braze compound when in a molten state.

49. A heat pipe for spreading heat according to claim 42 wherein said metal particles are selected from the group consisting of carbon, tungsten, copper, aluminum, magnesium, nickel, gold, silver, aluminum oxide, and beryllium oxide.

50. A heat pipe for spreading heat according to claim 42 wherein said metal particles comprise a shape selected from the group consisting of spherical, oblate spheroid, prolate spheroid, ellipsoid, polygonal, and filament.

51. A heat pipe for spreading heat according to claim 42 wherein said metal particles comprise at least one of copper spheres and oblate copper spheroids having a melting point of about one thousand eighty-three °

C.

52. A heat pipe for spreading heat according to claim 42 wherein said brazing compound comprises six percent by weight of a finely divided copper/gold brazing compound.

53. A heat pipe for spreading heat according to claim 42 wherein said brazing compound is present in the range from about two percent to about ten percent by weight.

54. A heat pipe for spreading heat according to claim 42 wherein said braze compound is selected from the group consisting of nickel-based Nicrobrazes, silver/copper brazes, tin/silver, lead/tin, and polymers.

55. A heat pipe for spreading heat according to claim 42 wherein said plurality of particles comprise aluminum and magnesium and said brazing compound comprises an aluminum/magnesium intermetallic alloy.

56. A heat pipe for spreading heat comprising:

a boundary structure including spaced-apart first and second plates that define an enclosed vapor chamber having a capillary structure 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;

at least one opening defined by a surrounding portion of said first plate which is bonded to said second plate so that said opening is isolated from said vapor chamber; and

at least one post formed on said second plate which projects into said vapor chamber and is bonded to said first plate.

57. A heat pipe for spreading heat according to claim 56 wherein said at least one post formed on said second plate comprises a flat portion that is in contact with an inner surface of said first plate.

58. A heat pipe for spreading heat according to claim 56 wherein said spaced-apart first and second plates include confronting interior surfaces;

and

a wick positioned upon said confronting interior surfaces including that portion of the interior surface of said first plate that forms said surrounding portion.

59. A heat pipe for spreading heat according to claim 56 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.

60. A heat pipe for spreading heat according to claim 56 wherein said brazing compound comprises about sixty-five percent weight copper and thirty-five percent weight gold particles such that said fillets of said brazing compound are formed between adjacent ones of said plurality of particles so as to create a network of capillary passageways between said particles.

61. A heat pipe for spreading heat according to claim 56 wherein said fillets are formed by capillary action of said braze compound when in a molten state.

62. A heat pipe for spreading heat according to claim 56 wherein said metal particles are selected from the group consisting of carbon, tungsten, copper, aluminum, magnesium, nickel, gold, silver, aluminum oxide, and beryllium oxide.

63. A heat pipe for spreading heat according to claim 56 wherein said particles comprise a shape selected from the group consisting of spherical, oblate spheroid, prolate spheroid, ellipsoid, polygonal, and filament.

64. A heat pipe for spreading heat according to claim 56 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.

65. A heat pipe for spreading heat according to claim 60 wherein said brazing compound comprises six percent by weight of a finely divided copper/gold brazing compound.

66. A heat pipe for spreading heat according to claim 60 wherein said brazing compound is present in the range from about two percent to about ten percent by weight.

67. A heat pipe for spreading heat according to claim 60 wherein said particles comprise copper powder comprising particles sized in a range from about twenty mesh to about two-hundred mesh.

68. A heat pipe for spreading heat according to claim 56 wherein said braze compound is selected from the group consisting of nickel-based Nicrobrazes, silver/copper brazes, tin/silver, lead/tin, and polymers.

69. A heat pipe for spreading heat according to claim 56 wherein said plurality of particles comprise aluminum and magnesium and said brazing compound comprises an aluminum/magnesium intermetallic alloy.