Nano-composite materials for thermal management applications

• US 20050116336A1
• Filed: 09/16/2004
• Published: 06/02/2005
• Est. Priority Date: 09/16/2003
• Status: Abandoned Application

• Current Assignee: Koila, Inc., Nasreen Chopra
• Original Assignee: Koila, Inc.
• Inventors: Banerjee, Shilajeet, Chopra, Nasreen G.
• Application Number:
  US10/944,472
• Publication Number:
  US 20050116336A1
• Time in Patent Office: Days
• US Class Current: 257/720
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: C09K 5/14 Solid materials, e.g. powdery or granular
• CPC Class Codes: H01L 23/373 Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
• 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

Nano-composite materials with enhanced thermal performance that can be used for thermal management in a wide range of applications, including heat sinks, device packaging, semiconductor device layers, printed circuit boards and other components of electronic, optical and/or mechanical systems. One type of nano-composite material has a base material and nanostructures (e.g., nanotubes) dispersed in the base material. Another type of nano-composite material has layers of a base material with nanotube films disposed thereon.

Claims

1. A nano-composite material comprising:

a metal base material having a base thermal conductivity; and

a plurality of nanostructures dispersed in said metal base material,

wherein said nano-composite material has a higher thermal conductivity than the base thermal conductivity.

2. The nano-composite material of claim 1 wherein said nanostructures include nanotubes.

3. The nano-composite material of claim 2 wherein said nanotubes are randomly oriented with respect to each other.

4. The nano-composite material of claim 2 wherein said nanotubes are generally aligned with each other so as to define a thermal path through at least a portion of the nano-composite material.

5. The nano-composite material of claim 2 wherein said nanotubes include boron nitride nanotubes.

6. The nano-composite material of claim 2 wherein said nanotubes include carbon nanotubes.

7. The nano-composite material of claim 1 wherein said metal base material includes at least one metal selected from a group consisting of aluminum, copper, indium, nickel, aluminum alloys, copper alloys, indium alloys, and nickel alloys.

8. The nano-composite material of claim 1 wherein the concentration of said nanostructures is between about 1% and about 25% by weight.

9. The nano-composite material of claim 1 wherein the concentration of said nanostructures is between about 1% and about 25% by volume.

10. The nano-composite material of claim 1 wherein the thermal conductivity of said nano-composite material is higher than the base thermal conductivity by a factor of at least about two.

11. The nano-composite material of claim 1 wherein said nanostructures are substantially uniformly dispersed in said metal base material.

12. The nano-composite material of claim 1 wherein said nanostructures include one or more nanostructures selected from the group consisting of nanotubes, fullerenes, nanorods, nanofibers, and nanocrystals.

13. A nano-composite material comprising:

a first base layer of a first base material;

a second base layer of a second base material; and

a film layer including a plurality of nanotubes, said film layer being disposed between and in thermal contact with each of said first and second base layers.

14. The nano-composite material of claim 13 wherein said first base material has a base thermal conductivity and said nano-composite material has a higher thermal conductivity than the base thermal conductivity.

15. The nano-composite material of claim 13 wherein said first base material and said second base material are of substantially the same composition.

16. The nano-composite material of claim 13 wherein said first base material and said second base material are of substantially different compositions.

17. The nano-composite material of claim 16 wherein one of said first and second base materials includes copper and wherein the other of said first and second base materials includes aluminum.

18. The nano-composite material of claim 13 wherein said nanotubes in said film layer are arranged with spaces between at least some of said nanotubes and others of said nanotubes.

19. The nano-composite material of claim 18 wherein the film layer further comprises an interstitial material substantially filling said spaces between said nanotubes.

20. The nano-composite material of claim 18 wherein said interstitial material is made of the base material.

21. The nano-composite material of claim 18 wherein said interstitial material is a viscous fluid material.

22. The nano-composite material of claim 18 wherein said interstitial material is a deposited film that substantially conforms to said spaces.

23. The nano-composite material of claim 13 wherein said nanotubes in said film layer are densely packed.

24. The nano-composite material of claim 13 wherein said film layer further includes a gap region characterized by an absence of nanotubes and wherein said second layer extends into said gap region.

25. The nano-composite material of claim 13 wherein said nanotubes are generally aligned with each other.

26. The nano-composite material of claim 25 wherein said nanotubes are further generally aligned at substantially right angles to the first layer.

27. The nano-composite material of claim 13 wherein said film layer further includes a first region comprising nanotubes that are generally aligned to a first axis and a second region comprising nanotubes that are generally aligned to a second axis, wherein the first axis and the second axis define different directions.

28. The nano-composite material of claim 27 wherein the first axis is substantially perpendicular to the second axis.

29. The nano-composite material of claim 27 wherein the first layer is substantially planar, the first axis is substantially perpendicular to the first layer and the second axis is substantially parallel to the first layer.

30. The nano-composite material of claim 13 wherein said first layer and said second layer are substantially planar.

31. The nano-composite material of claim 13 wherein said base material comprises a metal.

32. The nano-composite material of claim 31 wherein said metal is selected from a group consisting of aluminum, copper, indium, aluminum alloys, copper alloys, and indium alloys.

33. The nano-composite material of claim 13 wherein said base material comprises a semiconductor material.

34. The nano-composite material of claim 33 wherein said semiconductor material is selected from a group consisting of silicon, germanium, and gallium arsenide.

35. The nano-composite material of claim 13 wherein said base material comprises a polymer.

36. The nano-composite material of claim 13 wherein said film layer includes interspersed nanotubes of a first film sublayer and a second film sublayer, said first film sublayer being attached to said first base layer;

and said second film sublayer being attached to said second base layer.

37. A nano-composite material comprising:

a first plurality of base layers, each base layer made of a base material; and

a second plurality of film layers, each film layer comprising nanotubes, each of said film layers being disposed between and in contact with a pair of layers in said plurality of base layers.

38. The nano-composite material of claim 37 wherein said nano-composite material has a higher thermal conductivity than any of the base layers.

39. The nano-composite material of claim 37 wherein each of the base layers is made of the same base material.

40. The nano-composite material of claim 37 wherein at least one of said film layers includes interspersed nanotubes of a first film sublayer and a second film sublayer, said first film sublayer being attached to a first one of said base layers;

and said second film sublayer being attached to a second one of said base layers.

41. An article of manufacture with enhanced thermal performance, the article comprising:

a body having a first surface and a second surface,

wherein at least a portion of said body is formed of a nano-composite material that includes a base material and nanostructures incorporated into said base material, and

wherein said nanostructures enhance thermal performance of the article, relative to a similar article made of the base material, in at least one respect.

42. The article of claim 41 wherein said enhanced thermal performance in at least one respect includes a higher thermal transfer efficiency through said portion of said body.

43. The article of claim 41 wherein said enhanced thermal performance in at least one respect includes a higher thermal conductivity.

44. The article of claim 41 wherein said first surface is adapted for convective heat transfer between the body portion and a region of fluid.

45. The article of claim 41 wherein said first surface is adapted for conductive heat transfer between the body portion and another object.

46. The article of claim 41 wherein said nanostructures have a higher thermal conductivity than said base material.

47. The article of claim 41 wherein said nanostructures include nanotubes.

48. The article of claim 47 wherein said nanotubes are randomly oriented.

49. The article of claim 47 wherein said nanotubes are generally aligned with each other.

50. The article of claim 47 wherein said nano-composite material includes a nanotube film layer disposed between two layers of said base material.

51. The article of claim 50 wherein the nanotubes in said nanotube film layer are generally aligned with each other.

52. The article of claim 51 wherein axes of the nanotubes in said nanotube film layer are substantially normal to a surface of one of said two layers of said base material.

53. The article of claim 47 wherein said nanotubes include at least one of carbon nanotubes or boron nitride nanotubes.

54. The article of claim 41 wherein said nanostructures include one or more nanostructures selected from the group consisting of nanotubes, fullerenes, nanorods, nanofibers, and nanocrystals.

55. The article of claim 41 wherein said base material includes one or more materials selected from the group consisting of copper, aluminum, steel, titanium, and polyimide.

56. The article of claim 41 wherein said body is shaped as a package for a semiconductor device.

57. The article of claim 41 wherein said body is shaped as a semiconductor device.

58. The article of claim 41 wherein said body is shaped as a printed circuit board

59. The article of claim 41 wherein said body is shaped as a heat sink.

60. The article of claim 41 wherein said body is shaped as a heat pipe.

61. The article of claim 41 wherein said body is shaped as an automobile radiator.

62. The article of claim 41 wherein said body is shaped as a plastic housing for a consumer electronic device.

63. A heat transfer device for enhancing thermal transfer between an object and a region of fluid distinct from the object, the heat transfer device comprising:

a body formed of a nano-composite material that includes a base material and nanostructures incorporated into said base material, said body having first and second surfaces,

said first surface being adapted to contact the object; and

said second surface being adapted to contact the fluid, said second surface being characterized by macroscopic protrusions to increase a surface area that is in contact with the fluid.

64. The heat transfer device of claim 63 wherein said protrusions on said second surface are in the form of fins having generally rectangular cross-sectional profiles.

65. The heat transfer device of claim 63 wherein said nanostructures have a higher thermal conductivity than said base material.

66. The heat transfer device of claim 63 wherein said nanostructures include nanotubes.

67. The heat transfer device of claim 66 wherein said nanotubes are randomly oriented.

68. The heat transfer device of claim 66 wherein said nanotubes are generally aligned with each other.

69. The heat transfer device of claim 66 wherein said nano-composite material includes a nanotube film layer disposed between two layers of said base material.

70. The heat transfer device of claim 69 wherein the nanotubes in said nanotube film layer are generally aligned with each other.

71. The heat transfer device of claim 70 wherein axes of the nanotubes in said nanotube film layer are substantially normal to a surface of one of said two layers of said base material.

72. The heat transfer device of claim 66 wherein said nano-composite material includes a plurality of layers of said base material, each of said layers having a nanotube film layer disposed on at least one side thereof.

73. The heat transfer device of claim 66 wherein said nanotubes include at least one of carbon nanotubes or boron nitride nanotubes.

74. The heat transfer device of claim 63 wherein said nanostructures include one or more nanostructures selected from the group consisting of nanotubes, fullerenes, nanorods, nanofibers, and nanocrystals.

75. The heat transfer device of claim 63 wherein said base material includes a metal.

76. The heat transfer device of claim 75 wherein said metal is selected from the group consisting of aluminum, copper, indium, aluminum alloys, copper alloys, and indium alloys.

77. A heat sink for enhancing thermal transfer between an object and a region of fluid distinct from the object, the heat sink comprising:

a body having a bottom contact surface adapted to contact the object and a top contact surface adapted to contact the fluid,

wherein said body is formed of a plurality of fin elements extending generally upward from said bottom contact surface, each fin element having first and second side surfaces,

each fin element further having a plurality of nanotubes disposed on at least one of the first and second side surfaces of that fin element.

78. The heat sink of claim 77 wherein different ones of said fin elements extend upward from said bottom contact surface by different heights.

79. The heat sink of claim 78 wherein shorter ones of said fin elements are disposed between taller ones of said fin elements.

80. The heat sink of claim 77 wherein said first and second side surfaces of each of said fin elements extend upward from said bottom contact surface in a direction substantially normal to said bottom contact surface.

81. The heat sink of claim 77 wherein said first and second side surfaces of each of said fin elements are substantially planar.

82. The heat sink of claim 77 wherein said body further includes:

a bottom layer disposed below said fin elements and oriented substantially parallel to said bottom contact surface; and

a plurality of nanotubes disposed on at least one surface of said bottom layer.

83. The heat sink of claim 77 wherein at least one of said fin elements has nanotubes disposed on both of the first and second side surfaces of that fin element.

84. The heat sink of claim 77 further comprising a fastener disposed at or near said bottom contact surface and adapted to fixedly hold said fin elements in position.

85. The heat sink of claim 84 wherein said fastener is a bolt or a rivet.

86. The heat sink of claim 84 wherein said fastener is a mechanical band.

87. The heat sink of claim 84 wherein said fastener includes an adhesive material.

88. The heat sink of claim 84 wherein said fin elements are edge-bonded together at or near said bottom contact surface.

89. The heat sink of claim 77 wherein said nanotubes include carbon nanotubes and/or boron nitride nanotubes.

90. The heat sink of claim 77 wherein said nanotubes form a substantially continuous film on the base layers.

91. The heat sink of claim 77 wherein said nanotubes are arranged in spaced-apart bundles, each bundle including one or more nanotubes.

92. The heat sink of claim 77 wherein said nanotubes on one of said fin elements are generally aligned along a common axis.

93. The heat sink of claim 92 wherein said common axis is substantially normal to a surface of said one of said fin elements.

94. The heat sink of claim 77 wherein different ones of said fin elements are made of different materials.

95. The heat sink of claim 77 wherein one or more of said fin elements is made at least in part of a material selected from a group consisting of aluminum, copper, and indium.

96. A printed circuit board made of a nano-composite material that includes:

an electrically insulating base material; and

nanostructures incorporated into said base material,

wherein said nanostructures enhance thermal performance of the printed circuit board, relative to a printed circuit board made of the base material, in at least one respect but do not substantially enhance an electrical conductivity of the printed circuit board.

97. The printed circuit board of claim 96 wherein said enhanced thermal performance in said at least one respect includes a higher thermal conductivity.

98. The printed circuit board of claim 96 wherein said nanostructures have a higher thermal conductivity than said base material.

99. The printed circuit board of claim 96 wherein said nanostructures include nanotubes.

100. The printed circuit board of claim 99 wherein said nanotubes include a first group of nanotubes that are generally aligned with each other and oriented so as to define a thermal path through at least a first portion of said body.

101. The printed circuit board of claim 100 wherein said nanotubes further include a second group of nanotubes that are generally aligned with each other and oriented in a different direction from said first group of nanotubes.

102. The printed circuit board of claim 100 wherein said first group of nanotubes is arranged to underlie a device-mounting location on a first surface of said printed circuit board.

103. The printed circuit board of claim 99 wherein said nanotubes include boron nitride nanotubes.

104. The printed circuit board of claim 96 wherein said nanostructures include diamond nanocrystals.

105. The printed circuit board of claim 96 wherein said nanostructures include randomly oriented nanotubes.

106. An integrated circuit device comprising:

a device layer including a heat-generating circuit component,

wherein said device layer is formed of a nano-composite material that includes a base material and nanostructures incorporated into said base material, and

wherein said nanostructures enhance thermal performance of the integrated circuit device, relative to an integrated circuit device made of the base material, in at least one respect.

107. The integrated circuit device of claim 106 wherein said enhanced thermal performance in at least one respect includes a higher thermal conductivity.

108. The integrated circuit device of claim 106 wherein said nanostructures include nanotubes.

109. The integrated circuit device of claim 108, wherein said nanotubes include a first group of nanotubes that are generally aligned with each other and oriented so as to define a first thermal path through said portion of said device layer.

110. The integrated circuit device of claim 108 wherein said nanotubes further include a second group of nanotubes that are generally aligned with each other and oriented so as to define a second thermal path through at least a second portion of said device layer.

111. The integrated circuit device of claim 110 wherein said first group of nanotubes and said second group of nanotubes are oriented in different directions.

112. The integrated circuit device of claim 108 wherein said nanotubes include boron nitride nanotubes.

113. An integrated circuit device comprising:

a substrate layer formed of a semiconductor material;

a first film layer disposed on said substrate layer, said first film layer comprising first nanotubes; and

an active layer disposed on said first film layer, said active layer including at least one heat-generating circuit component,

wherein said first film layer provides a thermal path between said active layer and said substrate layer.

114. The integrated circuit device of claim 113 wherein said active layer is formed of a nano-composite material that includes a base semiconductor material and second nanotubes incorporated into at least one region of said base semiconductor material, and

wherein said second nanotubes are arranged to provide a thermal path through said at least one region.

115. The integrated circuit device of claim 114 wherein said second nanotubes are boron nitride nanotubes.

116. The integrated circuit device of claim 113, further comprising a second film layer disposed on a bottom surface of said substrate layer, said second film layer comprising second nanotubes.

117. A package for an integrated circuit device, the package including:

a section formed of a nano-composite material that includes a base material and nanostructures incorporated into said base material,

wherein said nanostructures enhance thermal performance of the package, relative to a package made of the base material, in at least one respect.

118. The package of claim 117 wherein said enhanced thermal performance in at least one respect includes an increased heat transfer rate between an inner surface of said package and an outer surface of said package.

119. The package of claim 117 wherein said nanostructures include nanotubes.

120. The package of claim 119 wherein said nanotubes include a group of nanotubes that are generally aligned with each other and oriented so as to define a thermal path through said section.

121. The package of claim 120, wherein said thermal path extends from an inner surface of the package toward an outer surface of the package.

122. An injection-molded plastic part, the part including:

at least one section formed of a nano-composite material that includes a plastic base material and nanostructures incorporated into said plastic base material,

wherein said nanostructures enhance thermal performance of the plastic part, relative to a plastic part made of the plastic base material, in at least one respect.

123. The plastic part of claim 122 wherein said enhanced thermal performance in at least one respect includes a higher heat dissipation rate.

124. The plastic part of claim 122 wherein said nanostructures include nanotubes.

125. The plastic part of claim 122 wherein said nanotubes include a group of nanotubes that are generally aligned with each other and oriented so as to define a thermal path through said section.

126. The package of claim 125, wherein said thermal path extends from an inner surface of the package toward an outer surface of the package.

127. The plastic part of claim 122 wherein said part is shaped as a component of a laptop computer case.

128. The plastic part of claim 122 wherein said part is shaped as a component of a housing for a telephone handset.

129. The plastic part of claim 122 wherein said part is shaped as a component of a housing for a personal digital assistant.