TWI246879B - Thermal interface material and method for making same - Google Patents

Abstract

A thermal interface material includes a macromolecule material having a first surface and a second surface opposite to the first surface, and an array of carbon nanotubes incorporated in the macromolecule material wherein the carbon nanotubes are opened in both ends and extending from the first surface to the second surface. Further, the carbon nanotubes are extending out from the both surfaces of the thermal interface material to form bendings. A preferred method for making the thermal interface material includes the steps of: (a) forming an array of carbon nanotubes; (b) immersing and spreading the array of carbon nanotubes in a melted macromolecule material; (c) curing the macromolecule material; (d) cutting the solidified macromolecule at a predetermined height to obtain a thermal interface material having the array of carbon nanotubes secured therein.

Description

1246879 Case No. 93110604

V. INSTRUCTION DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a thermal interface material and a method for producing the same, and particularly to a thermal interface material using a carbon nanotube heat conduction and a method for producing the same. [Prior Art] In recent years, with the rapid development of semiconductor device integration processes, the degree of integration of semiconductor devices has become higher and higher. However, as devices become smaller and smaller, and their demand for heat dissipation is increasing, it has become an increasingly important question. In order to meet this need, various heat dissipation methods such as fan heat dissipation, water cooling auxiliary heating and heat pipe heat are widely used, and the brigade obtains a certain heat dissipation effect, but the contact interface between the heat sink and the semiconductor integrated device is not flat, and generally the contact area is not uniform. 2%, there is no ideal contact interface, which fundamentally affects the effect of heat transfer from the semiconductor device to the heat sink. Therefore, a higher thermal transfer coefficient interface material is added between the heat sink and the semiconductor device to increase interface contact. The degree is really necessary. ... 曰The traditional thermal interface material is a high-heat-conducting particle-dispersing matrix to form a composite material, such as graphite, boron nitride, oxidized stone, oxygen, rubber S, and its 丄: the thermal conductivity of this f material depends on When the silver gum base is used, the composite material with the liquid phase change material as the matrix is less in contact with the original surface due to its ^^ it m & ^... / original surface infiltration, & The composite of the carrier is 、,], and the general defect of the material is relatively large. The material is 1仏κ, which has become more and more accurate. The typical value of the thermoacoustic system is small, and the typical value is the demand for heat dissipation. The increase of the degree of integration of the silver conductor is as close as possible to the particles. The hot particle content makes the number of particles, such as some special interface materials #: " a composite material of the guide family, a material can therefore reach 4, / mK, only, silver 1246879 case number 93110604 94. 23 years Lunar Amendment V. Description of the invention (2) When the content of the thermal conductive particles of the rubber matrix is increased to a certain extent, the silver gel matrix loses its original properties. Hard, thus losing the flexibility it deserves, will greatly degrade the performance of the thermal interface material. Recently, there is a thermal interface material in which an aligned carbon fiber having a thermal conductivity of about 1100 W/mK is fixed at one end or entirely by a polymer, thereby forming an aligned carbon fiber array in the vertical direction of the thermal interface material to make each carbon fiber. A heat conduction channel can be formed, which can effectively improve the thermal conductivity of the thermal interface material to reach 50-90 W/mK. However, one of the disadvantages of this type of material is that the thickness must be greater than 4 μm, and the thermal conductivity of the entire thermal interface material is inversely proportional to the thickness of the film. Therefore, when the thermal resistance is reduced to a certain extent, the space for further reduction is rather limited. In order to improve the performance of the thermal interface material and increase its heat transfer coefficient, various materials have been extensively tested. Savas Berber et al. published an article entitled "Unusually High Thermal Conductivity of Carbon Nanotube" at the American Physical Society in 2000. The ''Z'f-shaped 10) carbon nanotubes conduct heat at room temperature. The coefficient can reach 6 6 〇〇W/mK, with

See Phys· Rev. Lett ( 20 0 0 ), Vol· 84, P for physical content.

Page 8 4613. It is an important direction to study how to use carbon nanotubes for thermal interface materials and to give full play to their excellent thermal conductivity. U.S. Patent No. 6,407,9 22 discloses a heat transfer utilizing carbon nanotubes. The interface material is obtained by incorporating a carbon nanotube into a silver matrix to form a thermal interface material by a main mold method. The two thermal conduction materials of the thermal interface material 2 = the area is different, and the area of the surface contacting the heat sink is larger than the area of the two surfaces, which is beneficial to the heat dissipation of the heat sink. However, the party, the = 1246879 case number five, the invention description (3) the thickness of the thermal interface material obtained is incompatible with the body of the thermal interface material, and the advantage of the heat transfer in the matrix material is not sufficient. This small, soft blade is good [content] In order to solve the problem of the first thin and thermally conductive thermal interface material. In order to achieve the inclusion of a high score; the second surface of the thermal interface, the distribution and the formation of the heat-extracting surfaces to convert the nanocarbon tube array into a solid phase ^U〇6〇 £ The material is large, although the product is not used in the order of the heat transfer, the 'providing' thermal conductivity before the technical coefficient is insufficient to increase the heat, the uniformity of the surface material affects a uniform question, the connection, the interface material The lack of a device material, which is also subject to the thinness of the thickness of the thermal interface, is another object of providing the two-bending invention of the sub-material material of the invention, which is infiltrated and generated. The purpose is that the first and the plurality of nanometers have a first surface opening at both ends of the first tube, and the main mode is used to make the guiding system of the sputum system to the miniaturized square, but the flexibility; the complex development The trend of the United States to do eight # one, the carbon nanotubes of the plastic knife a uniformity is more difficult to determine the heat transfer coefficient of the double-tube longitudinal thermal conductivity. The surface material is t: the purpose of contact with the thermal resistance is to provide a thermal interface material with good flexibility and uniformity of thermal conductivity. A thermal interface material is provided, and the rabbit tube is distributed on the surface of the polymer material and relative to The first surface is uniformly extended to the second surface in the polymer material and extends separately to form a liquid distribution. The present invention provides a thermal interface material under the step of the first embodiment of the carbon nanotube array; a polymer composite material that makes a liquid phase polymer - 1 ^ 5;

Page 9 1246879 Yu·yp _ Case No. 93110604_年月日日_ί±ί-_ V. Description of invention (4) At a predetermined height of the carbon nanotube array, and cut along the axial direction of the vertical carbon nanotube array The polymer composite material removes the polymer material at the top of the carbon nanotube array and opens the tip of the carbon nanotube; the polymer composite material is cut according to a predetermined thickness to form a thermal interface material.

Compared with the thermal interface material of the prior art, the thermal interface material based on the thermal conductivity of the carbon nanotube array has the following advantages: First, the thermal interface material prepared by the invention has a uniform and super-inorganic carbon nanotube array. The advantages of the cis-aligning and aligning arrangement, each of the carbon nanotubes of the thermal interface material forms a heat-conducting channel in the direction of the vertical thermal interface material, so that the longitudinal heat conduction characteristics of the carbon nanotubes are utilized to the utmost extent, thereby obtaining heat conduction. The thermal interface material with high coefficient and uniform heat conduction; secondly, the thermal interface material prepared by the method is not limited by the growth height of the carbon nanotube array, and the thin interface can be obtained by cutting. The material can improve the thermal conductivity of the thermal interface material on the one hand, and increase the softness of the thermal interface material on the other hand, and reduce the volume and weight of the thermal interface material, which is beneficial to the development of electronic devices in the direction of miniaturization. Thirdly, the carbon nanotubes distributed in the thermal interface material of the present invention are open at both ends, and extend through the entire thermal interface material and expose both ends, the two ends The curved portion is substantially parallel to the surface of the thermal interface material. When applied, the curved portion at the end of the carbon nanotube can increase the direct contact area between the thermal interface material and the heat source or the heat sink, thereby facilitating better use of the carbon nanotubes. Thermal conductivity. [Embodiment] The present invention will be described in detail below with reference to the drawings and specific embodiments. Please refer to the first figure and the second figure, firstly forming uniformly on a substrate 11.

Page 10 Case No. 93110604 1246879 Month Amendment 曰 V. Description of Invention (5) A layer of catalyst film 12, which can be formed by thermal deposition, electron beam deposition or sputtering. The material of the substrate can be made of glass, quartz, enamel or alumina. This embodiment employs a porous crucible having a porous layer on its surface, and the diameter of the pores is extremely small, generally less than 3 nm. The material of the catalyst film 丨2 may be selected from other materials such as gallium nitride, cobalt, nickel and i alloy materials.氧化 Oxidation catalyst film 12, forming catalyst particles (not shown), and then placing the substrate 11 on which the catalyst particles are distributed in a reaction furnace (not shown), and introducing carbon source gas at 700 to 1000 degrees Celsius to grow A carbon nanotube array, wherein the carbon source gas can be a gas such as acetylene or ethylene, and the height of the carbon nanotube array can be controlled by controlling the growth time. The method for the growth of the carbon nanotube array 2 2 has been relatively mature, and can be found in the literature Science, 1 9 99, νο1·283, ρ· 512-414 and the literature: LAm.Chem.soc, 2〇〇1, ν〇 ι· 123, ρ· 1 1 5 02- 1 1 503, and a method of growing a large-area carbon nanotube array is also disclosed in U.S. Patent No. 6,350,488. Referring to the third figure, the molten polymer 32 is packed into a container 30, and the aligned aligned carbon nanotube array 2 2 is simultaneously introduced into the molten polymer 3 2 together with the substrate. Until the molten state polymer 3 2 completely infiltrate the carbon nanotube array 2 2 , the time at which the molten polymer 3 2 is completely wetted is related to the height and density of the carbon nanotube array 22 and the area of the entire nanotube array 22 . In order to completely infiltrate the carbon nanotube array 2 2 in the molten state polymer 3 2, the viscosity of the molten polymer 32 is 20 or less. The molten state polymer 32 of the present invention can also be replaced by a polymer solution or a polymer monomer solution. The molten polymer 3 2 used in this embodiment is a molten rocky soil material. Please refer to the fourth and fifth figures to completely dip the molten polymer 32.

1246879 94) 23⁄4 ----- Case No. 93110604 曰 ________ V. OBJECT DESCRIPTION (β) Runner carbon nanotube array 2 2 is taken out from vessel 30 together with substrate 11 and cooled to make the molten state high The molecule 3 2 is solidified to form a polymer material 34. Then, at a predetermined height of the carbon nanotube array 2 2, the polymer material 34 is cut perpendicular to the axial direction of the carbon nanotube array 2 2 by a microtome (not shown) to form a thermal interface material 40. The polymer material 34 after curing may be further removed from the substrate 11 and then cut to form a thermal interface material 40. In the method for manufacturing the thermal interface material 40 of the present invention, the molten polymer 32 may be cooled and solidified, and the cured molecular material 34 is taken out from the container 30 together with the substrate 11 and then directly used by a microtome. The carbon nanotube array 22 is axially cut to form the thermal interface material 40. The cast polymer material 34 is shaped according to the carbon nanotube array 2 2 the polymer material 34 is removed along the vertical 'carbon nanotube array nanometer The tip end of the carbon tube is cut in the same direction. The material 40 in the surface material 40 is exposed and the curved portion is substantially flat. The carbon nanotube end 24 is in contact with the poor thermal conductivity of the carbon nanotube. 1~1000 microns, the growth of this is straight to the upper mouth of Nai Li 22; then cut, that is, the end of the carbon tube end 2 4, in the bending of the heat 'increasing the thermal performance height will be obtained after the carbon nanotubes are redundant The two ends of the interface material are required to avoid direct contact. Thermal medium surface material of the embodiment of the invention

The specific method of cutting the slicer according to the present invention is as follows: firstly, the carbon material array 34 is cut in the axial direction of the carbon nanotube array 2 2, and the heat of the desired thickness of the interface material 40 is made at the same time. The interface material 40, the hot port, and the surface of the bend 40 are formed through the entire thermal interface 24. In application, the carbon nanotubes and the heat source or the scattered area, so as to better play the thickness of the thermal interface material 40 can be 1246879 ___ case number 93110604___年月日日正··· 5, invention description (7) The thickness of 40 is 20 microns. By controlling the position at which the slicer performs the cutting, the thickness of the thermal interface material 40 can be directly controlled by the slice as required, and the method is simple & easy to control. Further, depending on the cutting direction of the microtome, the carbon nanotube tips 24 may be formed to have different directions of curvature, and most of them will be substantially parallel to the surface of the thermal interface material 40. The thermal interface material 4 〇 of the present invention, the carbon nanotube array 2 2 is consolidated by the polymer material 34, so that the carbon nanotube array 22 has the characteristics of uniform distribution and vertical alignment in the polymer material 34, and is vertical. The direction of the film forms a heat conduction channel, and the formed thermal interface material 4 has the characteristics of high thermal conductivity and uniform heat conduction. In the thermal interface material prepared by the method, the morphology of the carbon nanotube array 2 2 distributed in the thermal interface material 40 is substantially unchanged, that is, the carbon nanotube array in the carbon nanotube array 2 2 The pitch is unchanged, and the carbon nanotube array 2 2 is not gathered into a bundle, maintaining the original aligned state, and the thermal interface material 4 has good flexibility. The two ends 24 of the carbon nanotubes extend out of the thermal interface material 4〇 and are parallel to the surface of the thermal interface material 40, which also exerts two in the application; the contact area of the source or the heat sink is more resistant to water and stone. Excellent thermal conductivity of the official. The carbon nanotube array thermal interface material _), power \ 曰 体 body heat can be widely used to include the central processing unit ^ ^ t Λ; 80 / Λ ^ ^ /, JaBa ^ (VGA) ^ ^ heat Between the devices 60, *提#: the two-sided material 40 is placed in contact with the electronic device 80, the thermal interface material 4 〇 , , , , , , , , , , , , , , , , , , , , , , , , , , , , Surface of device 80

Page 13 1246879 ___93110604 曰 曰 Revision 5, Invention Description (8) (not shown) contact, the second surface 44 of the thermal interface material 4 corresponding to the first surface 42 and the bottom surface of the heat sink 60 (not labeled) contact. Since the carbon nanotube array thermal interface material 4 〇 prepared by the present invention can control its thickness to a micron level, it has better flexibility, and thus, even in the case where the surface of the electronic device is jagged, the present invention The thermal interface material can also provide a good thermal contact between the electronic device 80 and the heat sink 60. In addition, since the carbon nanotubes in the thermal interface material 40 of the present invention are both open at both ends, and extend along the first surface 42 of the thermal interface material toward the second surface 44 and respectively protrude from the two surfaces 42, 44 form two bends. a surface 42 and a second table substantially parallel to the thermal interface material

Face 44. Therefore, it is better to ensure the direct contact between the carbon nanotubes and the electronic device 8〇 and the heat sink 60, so that the longitudinal thermal conductivity of the carbon nanotubes is utilized to the utmost extent, and the thermal interface material 4〇 has a high thermal conductivity and The characteristics of uniform heat conduction. As stated on the silk, the invention complies with the requirements of the invention patent and submits a patent application according to law. However, the above description is only the preferred embodiment of the present invention, and those skilled in the art, which are skilled in the art, are equivalently modified or changed in the present invention, and are included in the following claims.

1246879 _ Case No. 93110604_年月日日__ BRIEF DESCRIPTION OF THE DRAWINGS [Brief Description] The first figure is a schematic view of a substrate on which a catalyst film is formed in the present invention. The second figure is a schematic diagram of an array of aligned carbon nanotubes grown on a substrate as shown in the first figure. The third figure is a schematic diagram of the carbon nanotube array shown in the second figure together with the substrate soaked in the molten polymer. The fourth drawing is a schematic view showing the solidification of the carbon nanotube array in which the molten polymer is impregnated in the present invention. , -.

The fifth drawing is a schematic view of a thermal interface material comprising a carbon nanotube array in the present invention. The sixth drawing is a schematic diagram of the application of the thermal interface material of the present invention. [Main component symbol description]

Substrate 11 Catalyst layer 12 Carbon nanotube array 22 End 24 Container 30 Molten polymer 32 Polymer material 34 Thermal interface material 40 First surface 42 Second surface 44 Heat sink 60 Electronics 80

Page 15

Claims (1)

1246879 _ Case No. 93110604_年月日日__ VI. Patent application scope 1. A thermal interface material comprising: a south molecular material, and a plurality of carbon nanotubes distributed in the polymer material; wherein the thermal interface material Forming a first surface and a second surface opposite to the first surface, the carbon nanotubes are open at both ends, uniformly distributed in the polymer material and extending along the first surface of the thermal interface material to the second surface and extending respectively Two curves are formed on both surfaces. 2. The thermal interface material of claim 1, wherein the plurality of carbon nanotubes are substantially parallel to each other and perpendicular to the first surface and the second surface of the thermal interface material. 3. The thermal interface material of claim 1, wherein the plurality of carbon nanotubes form an array of carbon nanotubes. 4. The thermal interface material of claim 1, wherein the first surface of the thermal interface material is in contact with a heat source that is in contact with a heat sink. 5. The thermal interface material of claim 4, wherein the first surface and the second surface of the thermal interface material are parallel to each other. 6. The thermal interface material of claim 1, wherein the thermal interface material has a thickness of from 1 to 1 micron. 7. The thermal interface material of claim 1, wherein the high molecular material is stone. 8. A method of manufacturing a thermal interface material, comprising the steps of: providing a carbon nanotube array; infiltrating the carbon nanotube array in a liquid phase polymer system; Page 16 1246879 _ Case No. 93110604_年月日日_||i_ 6. Applying for the patent scope to convert the liquid phase polymer system into a solid phase, forming a polymer composite material with a carbon nanotube distributed; Arraying a predetermined height and cutting the polymer composite material perpendicular to the axial direction of the carbon nanotube array, removing the polymer material at the top of the carbon nanotube array and opening the tip of the carbon nanotube; cutting the polymer according to a predetermined thickness Composite material to form a thermal interface material. 9. The method for producing a thermal interface material according to claim 8, wherein the liquid phase polymer system has a viscosity of less than 200 c Ps. The method for producing a thermal interface material according to claim 8, wherein the liquid phase polymer system comprises a molten polymer, a polymer solution and a polymer monomer solution. 11. The method of producing a thermal interface material according to claim 10, wherein the molten state polymer comprises a molten paraffin material. 1 2. The method of producing a thermal interface material according to claim 8, wherein the carbon nanotube array is grown on a substrate. The method of manufacturing the thermal interface material according to claim 12, wherein the cutting the polymer composite material further comprises first removing the polymer composite material having the carbon nanotubes distributed from the substrate. . The method of manufacturing the thermal interface material according to claim 8, wherein the method for forming the carbon nanotube array comprises: a thermal chemical vapor deposition method, a plasma enhanced chemical vapor deposition method. Page 17 1246879 (4) 23 曰 Amendment---Cold No. 9311_4 _Year Month Chinese April Summary (Invention Name: A Thermal Interface Material and Its Manufacturing Method) Pipe Distribution Surface and Phase II of the High Second Table for Such Nano Carbonize the solution; by material. The heat is higher than the height of the surface of the molecular material surface extension heat interface tube array, and includes a material in the molecular material of the first surface of the first surface material The manufacturing method comprises: forming a distribution of the carbon nanotube array molecules, forming the distribution of the partial polymer material and the plurality of nano-carbon interface materials to form a first table, the carbon nanotubes are open at both ends, and the thermal interface material is The first surface is formed to be curved. The invention also includes the following steps: providing a polymer composite material immersed in a molten state; a polymer composite material of a solid carbon nanotube, forming a thermal interface 5, (1), the representative figure of the case is: the sixth figure (B), the representative symbol of the representative figure in this case is a simple description: Thermal interface material 40 First surface 42 English abstracts ~· THERMAL INTERFACE MATERIAL AND METHODE FOR MAKING~ A thermal interface material includes a macromolecule material having a first surface and a second surface opposite to the first surface, and an array of carbon nanotubes incorporated in the macromolecule material, the carbon nano tubes are opened in both ends and extending from the first surface to The second surface. Further, the carbon nanotubes are extending out Page 2 1246879 SS 93110604 Rev. 4, Chinese Abstract (Invention Name: A Thermal Interface Material and Its Manufacturing Method) Second Surface Electronic Device 44 80 Heat Sink 60 V. English Abstract SAME) (Invention Name: THERMAL INTERFACE MATERIAL AND METHODE FOR MAKING from the both surfaces of the thermal interface material to form bendings. A preferred method for making the thermal interface material includes the steps of: (a) forming an array of carbon nanotubes; (b) immersing and spreading the Array of carbon nanotubes in a melted macromo1 ecu 1e material ; (c) curing the macromo1 ecu 1 e material; (d) cutting the solidified macromo1 ecu 1 e at a 1246879 23⁄4 _ Case No. 93110604_年月日日_ Six, designated representative map