Graphite composite and method for producing graphite composite

Abstract

The present invention addresses the problem of providing a graphite composite having excellent thermal diffusivity and improved ease of rupture of an anisotropic graphite laminate. This problem can be solved by a graphite composite comprising: an anisotropic graphite laminate in which a plurality of graphite flakes are laminated in the Y-axis direction with a resin layer interposed therebetween in an XYZ space, and the crystal orientation plane of the graphite layer is arranged parallel to the XZ plane; the anisotropic graphite laminate has a first main surface and a second main surface parallel to an XY plane. A first metal layer on the first main surface; a second metal layer on the second main surface; and a reinforcing layer parallel to the YZ plane. The thickness of the first metal layer and the second metal layer is 2 [mu] m to 50 [mu] m.

Description

Technical Field

[0001] The present invention relates to a graphite composite and a method for manufacturing the graphite composite. Background Art

[0002] Graphite is widely used as an element for dissipating heat by transferring heat generated from electronic devices and electronic components.

[0003] In particular, anisotropic graphite having a graphite structure in which six-membered rings of carbon atoms are connected to each other by covalent bonds and the graphite structures are combined with each other by van der Waals forces has a high thermal conductivity. Therefore, anisotropic graphite has attracted attention as an element for effectively transferring heat generated from electronic devices and electronic components to dissipate heat.

[0004] For example, Patent Document 1 discloses anisotropic graphite, an anisotropic graphite composite, and a method for manufacturing the same, which have excellent heat transfer performance and long-term reliability as heat transfer elements. In the technology described in Patent Document 1, a titanium-containing metal layer, an inorganic material layer, etc. are formed on the main surface of the anisotropic graphite.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: WO2019 / 188915A1 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] The prior art as described above is excellent. However, as anisotropic graphite, in the case of using an anisotropic graphite laminate in which sheets of a plurality of anisotropic graphites are laminated with resin layers interposed therebetween, there is room for improvement in terms of achieving both improved heat diffusion ability and ease of cracking of the anisotropic graphite laminate.

[0010] An object of one aspect of the present invention is to provide a graphite composite having excellent heat diffusion ability and improved ease of cracking of the anisotropic graphite laminate.

[0011] Means for Solving the Problems

[0012] In order to solve the above-mentioned problems, a graphite composite according to an embodiment of the present invention includes the following configuration.

[0013] A graphite composite including:

[0014] An anisotropic graphite laminate, in the case where three mutually orthogonal spatial axes are defined as the X-axis, the Y-axis orthogonal to the X-axis, and the Z-axis perpendicular to the X-Y plane, the anisotropic graphite laminate is formed by laminating a plurality of graphite sheets in the Y-axis direction with a resin layer interposed therebetween, and the crystal orientation plane of the graphite layer is arranged parallel to the X-Z plane, and has a first main surface parallel to the X-Y plane and a second main surface on the opposite side of the first main surface;

[0015] A first metal layer provided on the first main surface of the aforementioned anisotropic graphite laminate;

[0016] A second metal layer provided on the second main surface of the aforementioned anisotropic graphite laminate; and

[0017] A reinforcing layer provided on at least one surface of the surface parallel to the Y-Z plane of the aforementioned anisotropic graphite laminate,

[0018] The thicknesses of the aforementioned first metal layer and the aforementioned second metal layer are each 2 μm to 50 μm.

[0019] In addition, in order to solve the aforementioned problems, the manufacturing method of a graphite composite according to an embodiment of the present invention includes the following configuration.

[0020] A method for manufacturing a graphite composite, the graphite composite comprising: an anisotropic graphite laminate, in the case where three mutually orthogonal spatial axes are defined as the X-axis, the Y-axis orthogonal to the X-axis, and the Z-axis perpendicular to the X-Y plane, the anisotropic graphite laminate is formed by laminating a plurality of graphite sheets in the Y-axis direction with a resin layer interposed therebetween, and the crystal orientation plane of the graphite layer is arranged parallel to the X-Z plane, and has a first main surface parallel to the X-Y plane and a second main surface on the opposite side of the first main surface,

[0021] The manufacturing method includes: a reinforcing step of forming a reinforcing layer on at least one surface of the surface parallel to the Y-Z plane of the anisotropic graphite laminate; and

[0022] A metal layer forming step of forming a first metal layer and a second metal layer on the first main surface and the second main surface of the anisotropic graphite laminate on which the aforementioned reinforcing layer is formed,

[0023] The thicknesses of the aforementioned first metal layer and the aforementioned second metal layer are each 2 μm to 50 μm.

[0024] Effects of the Invention

[0025] According to an embodiment of the present invention, as the anisotropic graphite, even in the case of using an anisotropic graphite laminate formed by laminating a plurality of sheets of anisotropic graphite with a resin layer interposed therebetween, a graphite composite having excellent thermal diffusion ability and improved cracking susceptibility of the anisotropic graphite laminate can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 FIG. is a diagram showing the structure of a graphite composite according to an embodiment of the present invention.

[0027] Figure 2 FIG. is a diagram showing the steps of a method for manufacturing a graphite composite according to an embodiment of the present invention.

[0028] Figure 3 FIG. is a diagram showing the structure of a test sample and a test apparatus for an evaluation test of heat transfer performance in an example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] An embodiment of the present invention will be described below, but the present invention is not limited thereto. The present invention is not limited to the respective configurations described below, and various modifications can be made within the scope shown in the claims. In addition, embodiments or examples obtained by combining technical means separately disclosed in different embodiments or examples are also included in the technical scope of the present invention. Furthermore, by combining the technical means separately disclosed in each embodiment, new technical features can be formed. It should be noted that all the academic documents and patent documents described in this specification are incorporated herein by reference. In addition, in this specification, unless otherwise specified, "A to B" indicating a numerical range means "A or more (including A and greater than A) and B or less (including B and less than B)".

[0030] [1. Basic Principle of the Present Invention]

[0031] As described above, in the technology described in Patent Document 1, a titanium-containing metal layer, an inorganic material layer, etc. are formed on the main surface of the anisotropic graphite. The inorganic material layer disposed on the main surface of the anisotropic graphite tends to hinder the excellent heat diffusion ability of the anisotropic graphite. Furthermore, the anisotropic graphite has a property of easily breaking along the crystal orientation plane of the graphite layer. The tendency of the inorganic material layer to hinder the heat diffusion ability and the property of easily breaking along the crystal orientation plane are the same even when an anisotropic graphite laminate in which a plurality of anisotropic graphite sheets are laminated with resin layers is used as the anisotropic graphite.

[0032] Therefore, from the viewpoint of heat diffusion ability, the component provided on the main surface of the anisotropic graphite laminate is desirably only a metal layer. Here, when forming a metal layer on the main surface of the anisotropic graphite laminate, as a method thereof, there are a method of directly forming a metal layer on the main surface of the anisotropic graphite laminate by plating or the like, a method of forming a metal layer on the main surface of the anisotropic graphite laminate by means of a metal layer adhesive containing a metal-based solder, a method of forming a metal layer on the main surface of the anisotropic graphite laminate by means of an organic adhesive, and the like. The organic adhesive tends to impede the excellent heat diffusion ability of the anisotropic graphite laminate. Therefore, among these methods, a method of directly forming a metal layer on the anisotropic graphite laminate by plating or the like, a method of forming a metal layer on the main surface of the anisotropic graphite laminate by means of a metal layer adhesive containing a metal-based solder, and the like are more preferable. In addition, as the anisotropic graphite, in the case of using an anisotropic graphite laminate in which a plurality of anisotropic graphite sheets are laminated with resin layers interposed therebetween, due to the presence of the resin layer, the heat resistance of the anisotropic graphite laminate is lower than the case where there is no resin layer. Therefore, a method of forming a metal layer under high temperature conditions, such as a method of forming a metal layer by means of a metal layer adhesive containing a metal-based solder, is not preferable. Therefore, a method of directly forming a metal layer on the anisotropic graphite laminate by plating or the like is further preferable. However, in the method of directly forming a metal layer on the anisotropic graphite laminate by plating or the like, the metal layer becomes thin. Therefore, the composite body formed by forming a metal layer on the main surface of the anisotropic graphite laminate by plating or the like cannot ensure the strength of the metal layer, and thus there is a problem that it is likely to break along the crystal orientation plane of the graphite layer.

[0033] Accordingly, an object of an embodiment of the present invention is to provide a graphite composite body which has excellent heat diffusion ability even in the case of using a laminate in which a plurality of graphite sheets are laminated with resin layers interposed therebetween as an anisotropic graphite laminate, and in which the easiness of breakage of the anisotropic graphite laminate is improved.

[0034] The present inventors have found the following, and thus completed the present invention: (i) the easiness of breakage of the anisotropic graphite laminate can be improved by an reinforcing layer having a unique configuration; (ii) since the reinforcing layer is provided, the components (for example, metal layers such as a first metal layer and a second metal layer) covering the periphery of the anisotropic graphite laminate can be made thin, and the components covering the periphery of the anisotropic graphite laminate can be simplified (for example, the components provided on the main surface of the anisotropic graphite laminate can be simplified to only the first metal layer and the second metal layer), whereby the heat diffusion ability of the graphite composite body can be improved; and (iii) the easiness of breakage of the anisotropic graphite laminate can be further improved by the thin components (for example, metal layers such as a first metal layer and a second metal layer) covering the periphery of the anisotropic graphite laminate.

[0035] According to one aspect of the present invention, as an anisotropic graphite laminate, even in the case of a laminate formed by laminating a plurality of graphite sheets with a resin layer interposed therebetween, a graphite composite having excellent thermal diffusion ability and improved fracture susceptibility of the anisotropic graphite laminate can be provided. Such an effect of one aspect of the present invention also contributes to achieving, for example, Goal 12, "Ensure sustainable consumption and production patterns," of the Sustainable Development Goals (SDGs) advocated by the United Nations.

[0036] 〔2. Graphite composite〕

[0037] Refer to Figure 1 A graphite composite according to one embodiment of the present invention will be described. It should be noted that Figure 1 is a diagram showing the configuration of a graphite composite according to one embodiment of the present invention.

[0038] A graphite composite 103 according to one embodiment of the present invention includes: an anisotropic graphite laminate 1, in a case where three mutually orthogonal spatial axes are defined as the X-axis, the Y-axis orthogonal to the X-axis, and the Z-axis perpendicular to the X-Y plane, the anisotropic graphite laminate 1 is formed by laminating a plurality of graphite sheets with a resin layer interposed therebetween in the Y-axis direction, and the crystal orientation plane 20 of the graphite layer is arranged parallel to the X-Z plane, and has a first main surface 30 parallel to the X-Y plane and a second main surface 31 on the opposite side of the first main surface 30; a first metal layer 3 provided on the first main surface 30 of the anisotropic graphite laminate 1; a second metal layer 4 provided on the second main surface 31 of the anisotropic graphite laminate 1; and a reinforcing layer 10 provided on at least one surface parallel to the Y-Z plane of the anisotropic graphite laminate 1, and the thicknesses of the first metal layer 3 and the second metal layer 4 are each 2 μm to 50 μm.

[0039] It should be noted that in this specification, for example, "the crystal orientation plane 20 is parallel to the X-Z plane" such as "plane A is parallel to plane B" means substantially parallel. Here, substantially parallel means, for example, a state where the angle formed by the normal of plane A and the normal of plane B is -10° to 10°.

[0040] As Figure 1 shown in 101, a graphite composite according to one embodiment of the present invention includes an anisotropic graphite laminate 1, in which the crystal orientation plane 20 of the graphite layer is arranged parallel to the X-Z plane, and has a first main surface 30 parallel to the X-Y plane and a second main surface 31 on the opposite side of the first main surface 30.

[0041] The anisotropic graphite laminate 1 is a laminate formed by laminating a plurality of graphite sheets with a resin layer interposed therebetween in the Y-axis direction, and may have a block shape (for example, a cube, a cuboid) (It should be noted that inFigure 1 and the following Figure 2 (in which the resin layer is not shown). Here, the graphite sheet refers to a graphite sheet formed by laminating a plurality of layers having a graphite structure in which six-membered rings of carbon atoms are connected to each other by covalent bonds (in other words, graphite layers) into a sheet-like shape. Therefore, in the anisotropic graphite laminate 1, the plurality of graphite sheets and the resin layer are arranged in parallel with the X-Z plane, similarly to the crystal orientation plane 20 of the graphite layer.

[0042] As the resin layer, a thermosetting resin and / or a thermoplastic resin can be used. That is, the resin layer contains at least one of a thermoplastic resin and a thermosetting resin. In addition, as the material of the resin layer, a film-like material or a varnish-like material can be used.

[0043] Examples of the thermosetting resin include PU (polyurethane), phenolic resin, vinyl ester resin, unsaturated polyester, epoxy resin, PI (polyimide-based) resin, PPE (polyphenylene ether), etc., and combinations of two or more of them. Among them, epoxy resin and PU are more preferred because they have a wide range of material selection and excellent adhesion to graphite sheets.

[0044] Examples of the thermoplastic resin include acrylic resin, EVA-based (ethylene-vinyl acetate copolymer-based) resin, PMMA (polymethyl methacrylate), PVC (polyvinyl chloride), aromatic polyamide, PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PS (polystyrene), PC (polycarbonate), aromatic polyester, polyethylene naphthalate (PEN), polyester-based resin, etc., and combinations of two or more of them. As the thermoplastic resin, it is more preferable to use a material containing an aromatic group (such as aromatic polyester and polyethylene terephthalate). With this configuration, when the resin layer is laminated, the resin layer is arranged substantially parallel to the plane of the graphite sheet, and the layers of the graphite sheet are less likely to be disordered during lamination, and a graphite laminate having a thermal conductivity close to the theoretical value can be obtained.

[0045] The glass transition temperature of the above-mentioned thermoplastic resin and the above-mentioned thermosetting resin is preferably 50 °C or higher, more preferably 60 °C or higher, further preferably 70 °C or higher, and particularly preferably 80 °C or higher. When the glass transition temperature is 50 °C or higher, air can be better prevented from entering the anisotropic graphite laminate. The glass transition temperature is preferably 250 °C or lower, more preferably 150 °C or lower, and further preferably 100 °C or lower. In addition, when using materials such as an acrylic adhesive and a rubber sheet with a glass transition temperature of 50 °C or higher, the strength of the resin layer is strong, and there is a tendency that the characteristics of the resin layer are less likely to deviate, so it is preferred. As other materials having such a glass transition temperature, PET (polyethylene terephthalate), PS (polystyrene), PC (polycarbonate), etc. can be cited.

[0046] The aforementioned glass transition temperature can be confirmed by measuring the resin layer using differential scanning calorimetry.

[0047] As the thickness of the aforementioned resin layer, it is preferably 100 μm or less, more preferably 50 μm or less, most preferably 15 μm or less, and particularly preferably 5 μm or less. The lower limit is preferably 0.1 μm, more preferably 2 μm. If the thickness of the aforementioned resin layer is 100 μm or less, 50 μm or less, 15 μm or less, especially 5 μm or less, the reduction in thermal properties caused by the resin layer is less, so it is preferred. In addition, from the viewpoint of adhesiveness, it is preferred that the thickness of the above resin layer is 0.1 μm or more, further 2 μm or more.

[0048] As the thickness of the aforementioned graphite sheet, it is preferably 2 μm to 50 μm, more preferably 10 μm to 50 μm, and further preferably 20 μm to 50 μm.

[0049] The massive anisotropic graphite laminate has high thermal conductivity in the direction parallel to the crystal orientation plane 20 of the graphite layer (for example, the X-axis direction and the Z-axis direction). The "anisotropy" of the anisotropic graphite laminate 1 means that due to the orientation of the graphite layer, there is a large difference in the thermal conductivity of the anisotropic graphite laminate 1 in the direction parallel to the crystal orientation plane 20 of the graphite layer (for example, the X-axis direction and the Z-axis direction) and the perpendicular direction (for example, the Y-axis direction). For such an anisotropic graphite laminate 1, it can be suitably produced by a known method such as the method described in the above-mentioned Patent Document 1.

[0050] The thermal conductivity in the X-axis direction and the Z-axis direction of the anisotropic graphite laminate 1 can be, for example, 1000 W / mK or more. The upper limit of the thermal conductivity in the X-axis direction and the Z-axis direction of the anisotropic graphite laminate 1 is not particularly limited and can be 2000 W / mK or less. On the other hand, the thermal conductivity in the Y-axis direction of the anisotropic graphite laminate 1 can be, for example, 0.3 W / mK or more and 20 W / mK or less.

[0051] The first main surface 30 is a surface parallel to the X-Y plane, and the second main surface 31 is a surface on the opposite side of the first main surface 30 parallel to the X-Y plane (in other words, a surface parallel to the X-Y plane). Therefore, in the anisotropic graphite laminate 1, heat can be efficiently transported along the Z-axis direction (for example, from the first main surface 30 toward the second main surface 31) and / or along the X-axis direction.

[0052] The thickness of the anisotropic graphite laminate 1 (the thickness in the Z-axis direction) is not limited, preferably 0.30 mm to 5.0 mm, more preferably 0.50 mm to 3.0 mm, and most preferably 0.70 mm to 2.0 mm. With such a configuration, a heat transfer element that is thin and can efficiently transport heat can be realized.

[0053] The thickness of the anisotropic graphite laminate 1 in the X-axis direction and the thickness in the Y-axis direction are not limited and can be appropriately set according to the intended use. The thickness of the anisotropic graphite laminate 1 in the X-axis direction and the thickness in the Y-axis direction can be, for example, 10 mm to 80 mm and 10 mm to 50 mm, respectively.

[0054] As Figure 1 shown, the graphite composite 103 according to one embodiment of the present invention includes a first metal layer 3 provided on the first main surface 30 of the anisotropic graphite laminate 1 and a second metal layer 4 provided on the second main surface 31 of the anisotropic graphite laminate 1.

[0055] As described above, in the anisotropic graphite laminate 1, since heat is efficiently transported along the Z-axis direction, heat of the anisotropic graphite laminate 1 can be efficiently transferred to other components through the first metal layer 3 and the second metal layer 4.

[0056] In addition, since at least a part of the surface of the anisotropic graphite laminate 1 is covered by the first metal layer 3 and the second metal layer 4, graphite powder can be prevented from falling off the anisotropic graphite laminate 1. If graphite powder can be prevented from falling off the anisotropic graphite laminate 1, for example, when the graphite composite according to one embodiment of the present invention is disposed in an electronic device, a short circuit of an electronic circuit caused by the graphite powder can be prevented.

[0057] In addition, through the first metal layer 3 and the second metal layer 4, the ease of cracking of the anisotropic graphite laminate 1 can be further improved.

[0058] The first metal layer 3 and the second metal layer 4 can be arranged to be in direct contact with the anisotropic graphite laminate 1, or can be arranged not to be in direct contact with the anisotropic graphite laminate 1, but it is more preferably arranged to be in direct contact with the anisotropic graphite laminate 1. If such a configuration is adopted, since heat can be directly transferred between the anisotropic graphite laminate 1 and the first metal layer 3 and the second metal layer 4, a thin heat transfer element capable of efficiently conducting heat can be realized. In addition, if such a configuration is adopted, through the first metal layer 3 and the second metal layer 4, at least a part of the surface of the anisotropic graphite laminate 1 can be more reliably covered, and at the same time, the ease of cracking of the anisotropic graphite laminate 1 can be more reliably improved.

[0059] The configurations of the first metal layer 3 and the second metal layer 4 are not particularly limited, and can be a metal vapor deposition layer, a metal layer based on sputtering treatment, a metal layer based on spraying, a plating layer, or a metal layer containing a metal-based solder. If such a configuration is adopted, the first metal layer 3 and the second metal layer 4 can be formed thinner, so a thin heat transfer element capable of efficiently conducting heat can be realized. In addition, if such a configuration is adopted, the first metal layer 3 and the second metal layer 4 can be formed on the anisotropic graphite laminate 1 without relying on other configurations. Since the heat resistance of the anisotropic graphite laminate is reduced due to the presence of the resin layer compared to the case without the resin layer, the configurations of the first metal layer 3 and the second metal layer 4 are more preferably plating layers that do not require high-temperature conditions during layer formation. It should be noted that from the perspective of heat diffusion ability, the configuration provided on the main surface of the anisotropic graphite laminate is preferably only a metal layer, but the plating layer can also be a layer in which a metal layer and an inorganic material layer are integrated.

[0060] The materials of the first metal layer 3 and the second metal layer 4 are not particularly limited, and preferably contain at least one selected from copper, nickel, and gold. Therefore, the materials of the first metal layer 3 and the second metal layer 4 can all contain copper, nickel, and gold, or can contain copper and nickel, or can contain copper and gold, or can contain nickel and gold, or can contain any one of copper, nickel, and gold. Among these materials, the materials of the first metal layer 3 and the second metal layer 4 preferably contain copper, and more preferably are copper. If such a configuration is adopted, a heat transfer element that takes both cost and efficient heat transfer into account can be realized.

[0061] The thicknesses (thicknesses in the Z-axis direction) of the first metal layer 3 and the second metal layer 4 are independently 2 μm to 50 μm, preferably 3 μm to 30 μm, and more preferably 5 μm to 10 μm. If such a configuration is adopted, a heat transfer element capable of more efficiently conducting heat can be realized.

[0062] As Figure 1As shown, in one embodiment of the present invention, the graphite composite 103 preferably has a third metal layer 5 and a fourth metal layer 6 provided on two surfaces parallel to the X-Z plane in the anisotropic graphite laminate 1, respectively.

[0063] Since at least a part of the surface of the anisotropic graphite laminate 1 is covered by the third metal layer 5 and the fourth metal layer 6, graphite powder can be prevented from falling off the anisotropic graphite laminate 1.

[0064] In addition, through the third metal layer 5 and the fourth metal layer 6, the cracking susceptibility of the anisotropic graphite laminate 1 can be further improved.

[0065] The third metal layer 5 and the fourth metal layer 6 can be provided in direct contact with the anisotropic graphite laminate 1, or can be provided not in direct contact with the anisotropic graphite laminate 1, but it is more preferably provided in direct contact with the anisotropic graphite laminate 1. With this configuration, at least a part of the surface of the anisotropic graphite laminate 1 can be more reliably covered by the third metal layer 5 and the fourth metal layer 6, and at the same time, the cracking susceptibility of the anisotropic graphite laminate 1 can be more reliably improved.

[0066] The configurations of the third metal layer 5 and the fourth metal layer 6 can be the same as those of the first metal layer 3 and the second metal layer 4. In addition, since heat transfer mainly occurs efficiently along the X-axis and the Z-axis and there is little heat transfer along the Y-axis, the third metal layer 5 and the fourth metal layer 6 can also be formed as metal layers with the aid of an organic binder.

[0067] The thicknesses (thicknesses in the Y-axis direction) of the third metal layer 5 and the fourth metal layer 6 are not particularly limited, and are each independently preferably 2 μm to 50 μm, more preferably 3 μm to 30 μm, and most preferably 5 μm to 10 μm. With this configuration, not only can the falling of graphite powder from the anisotropic graphite laminate 1 be prevented, but also a thin heat transfer element can be realized.

[0068] As Figure 1 shown, the graphite composite 103 according to one embodiment of the present invention includes a reinforcing layer 10 provided on at least one surface in the surface parallel to the Y-Z plane of the anisotropic graphite laminate 1. In the graphite composite 103 according to one embodiment of the present invention, the reinforcing layer 10 is more preferably provided on two surfaces parallel to the Y-Z plane of the anisotropic graphite laminate 1. Figure 1 102 schematically shows a configuration in which the first metal layer 3, the second metal layer 4, the third metal layer 5, and the fourth metal layer 6 are not provided.

[0069] The anisotropic graphite laminate has the property of being easily broken along the X-Z plane (crystalline orientation plane 20). Therefore, by providing the reinforcing layer 10 on at least one surface in the surface parallel to the Y-Z plane, the breakage susceptibility of the anisotropic graphite laminate 1 can be improved.

[0070] The thickness of the reinforcing layer 10 (thickness in the X-axis direction) is not limited, and is preferably 50 μm to 500 μm, more preferably 100 μm to 400 μm, and most preferably 150 μm to 300 μm, respectively independently. With such a configuration, not only can the breakage susceptibility of the anisotropic graphite laminate 1 be improved, but also a thin heat transfer element can be realized.

[0071] The thickness of the reinforcing layer 10 in the Y-axis direction and the thickness in the Z-axis direction are not limited, and can be appropriately set according to the size of the anisotropic graphite laminate 1.

[0072] The material of the reinforcing layer 10 is not particularly limited, and preferably contains at least one selected from the group consisting of resins (such as polypropylene, polyethylene, polyethylene terephthalate, polycarbonate, modified resins added with various additives, elastomers), metals (such as gold, silver, copper, nickel, aluminum, molybdenum, tungsten, alloys containing them, and metal-based solders), and ceramics (such as alumina, zirconia, silicon carbide, silicon nitride, boron nitride, and aluminum nitride). With such a configuration, the breakage susceptibility of the anisotropic graphite laminate 1 can be suppressed. From the viewpoint of better obtaining this advantage, among the above resins, polycarbonate and polyethylene terephthalate are further preferred, among the above metals, copper and aluminum are further preferred, and among the above ceramics, alumina and silicon carbide are further preferred.

[0073] As Figure 1 shown, the graphite composite of one embodiment of the present invention may include an adhesive layer 11 between the anisotropic graphite laminate 1 and the reinforcing layer 10. With such a configuration, the anisotropic graphite laminate 1 and the reinforcing layer 10 can be bonded by means of the adhesive layer 11.

[0074] The adhesive layer 11 only needs to be able to bond the anisotropic graphite laminate 1 and the reinforcing layer 10, and its configuration is not limited. As the material of the adhesive layer 11, for example, metal-based solders, acrylic adhesives, epoxy adhesives, solders, adhesives, and various adhesive tapes can be cited. Among them, due to the presence of the resin layer, the heat resistance of the anisotropic graphite laminate is lower than that in the case where there is no resin layer. Therefore, as the material of the adhesive layer 11, acrylic adhesives, epoxy adhesives, adhesives, and various adhesive tapes that do not require high-temperature conditions are more preferred.

[0075] In addition, examples of the adhesive tape described above include acrylic resin adhesive tapes, epoxy resin adhesive tapes, fluororesin adhesive tapes, silicone-based adhesive tapes, polyimide adhesive tapes, etc. From the perspective of heat resistance, silicone-based adhesive tapes and polyimide adhesive tapes are more preferred.

[0076] When using an adhesive tape as the adhesive layer 11, it can be cut into any size according to a known method to bond the reinforcing layer 10 to the anisotropic graphite laminate 1. In order to achieve a good bonding state between the reinforcing layer 10 and the anisotropic graphite laminate 1, a load can be applied from the reinforcing layer 10 to the anisotropic graphite laminate 1 during attachment.

[0077] The thickness of the adhesive layer 11 (thickness in the X-axis direction) is not limited, and each is independently preferably 5 μm to 500 μm, more preferably 8 μm to 100 μm, and most preferably 8 μm to 50 μm. With this structure, not only can the anisotropic graphite laminate 1 and the reinforcing layer 10 be firmly bonded, but also a thin heat transfer element can be realized.

[0078] The thickness of the adhesive layer 11 in the Y-axis direction and the thickness in the Z-axis direction are not limited and can be appropriately set according to the size of the anisotropic graphite laminate 1.

[0079] The graphite composite 103 according to one embodiment of the present invention may include a fifth metal layer 7 on the outer side of the reinforcing layer 10 (in other words, on the side of the reinforcing layer 10 opposite to the adhesive layer 11).

[0080] Since at least a part of the surface of the reinforcing layer 10 (in other words, at least a part of the surface of the anisotropic graphite laminate 1) is covered by the fifth metal layer 7, it is possible to better prevent graphite powder from falling off the anisotropic graphite laminate 1.

[0081] In addition, through the fifth metal layer 7, the ease of cracking of the anisotropic graphite laminate 1 can be further improved.

[0082] The composition of the fifth metal layer 7 is not particularly limited and can be the same as that of the first metal layer 3 and the second metal layer 4.

[0083] The thickness of the fifth metal layer 7 (thickness in the X-axis direction) is not particularly limited, and each is independently preferably 2 μm to 50 μm, more preferably 3 μm to 30 μm, and most preferably 5 μm to 10 μm. With this configuration, not only can the falling of graphite powder from the anisotropic graphite laminate 1 be prevented, but also a thin heat transfer element can be realized.

[0084] The thickness of the fifth metal layer 7 in the Y-axis direction and the thickness in the Z-axis direction are not restricted and can be appropriately set according to the size of the anisotropic graphite laminate 1.

[0085] In addition, the reinforcing layer may be formed on a surface parallel to the XZ plane. That is, the graphite composite of one embodiment of the present invention may have a reinforcing layer provided on at least one surface parallel to the XZ plane of the anisotropic graphite stack (or both surfaces parallel to the XZ plane).

[0086] The structure outside the surface parallel to the XZ plane of the anisotropic graphite stack can be the same structure as the structure outside the surface parallel to the YZ plane of the anisotropic graphite stack (for example, a structure including the reinforcing layer 10, a structure including the reinforcing layer 10 and the adhesive layer 11, or a structure including the reinforcing layer 10, the adhesive layer 11 and the seventh metal layer).

[0087] [2. Method for producing graphite composite]

[0088] Reference Figure 1 and Figure 2 , a method for producing a graphite composite 103 according to an embodiment of the present invention will be described. It should be noted that the contents already described in the above-mentioned [1. Graphite composite] will be omitted here.

[0089] A method for producing a graphite composite 103 according to an embodiment of the present invention is a method for producing a graphite composite 103, wherein the graphite composite 103 comprises: an anisotropic graphite laminate 1, wherein, when three mutually orthogonal spatial axes are defined as an X-axis, a Y-axis orthogonal to the X-axis, and a Z-axis perpendicular to the XY plane, the anisotropic graphite laminate 1 is formed by laminating a plurality of graphite sheets in the Y-axis direction via a resin layer, and a crystal orientation plane 20 of the graphite layer is arranged parallel to the XZ plane, and has a The first main surface 30 and the second main surface 31 on the opposite side of the first main surface 30, the manufacturing method of the graphite composite 103 includes: a reinforcement process, forming a reinforcement layer 10 on at least one of the surfaces parallel to the YZ plane of the anisotropic graphite stack 1; and a metal layer forming process, forming a first metal layer 3 and a second metal layer 4 on the first main surface 30 and the second main surface 31 of the anisotropic graphite stack 1 formed with the reinforcement layer 10, respectively, and the thickness of the first metal layer 3 and the second metal layer 4 is 2μm to 50μm.

[0090] The reinforcing step is a step of forming a reinforcing layer 10 on at least one of the surfaces parallel to the YZ plane of the anisotropic graphite laminate 1 (or on both of the surfaces parallel to the YZ plane of the anisotropic graphite laminate 1) (see Figure 2 Process 1).

[0091] The specific configuration of the reinforcement process is not particularly limited. For example, (i) the reinforcement layer 10 can be directly bonded to the anisotropic graphite laminate 1, or (ii) the anisotropic graphite laminate 1 and the reinforcement layer 10 can be bonded with the aid of an adhesive layer 11. It should be noted that as a method of bonding the anisotropic graphite laminate 1 and the reinforcement layer 10 with the aid of the adhesive layer 11, a known method can be appropriately used according to the raw material of the adhesive layer 11.

[0092] In the case where an adhesive tape is used as the adhesive layer 11, the adhesive tape can be cut into any size according to a known method, and the reinforcement layer 10 can be bonded to the anisotropic graphite laminate 1 using the adhesive tape. In order to obtain a good bonding state between the reinforcement layer 10 and the anisotropic graphite laminate 1, a load can be applied from the reinforcement layer 10 to the anisotropic graphite laminate 1 during attachment.

[0093] The manufacturing method of the graphite composite 103 according to an embodiment of the present invention preferably includes a cutting process of cutting the reinforcement layer 10 and the anisotropic graphite laminate 1 (in other words, the composite of the reinforcement layer 10 and the anisotropic graphite laminate 1) after the above-mentioned reinforcement process.

[0094] In the cutting process, for example, the composite of the reinforcement layer 10 and the anisotropic graphite laminate 1 can be cut along a cutting plane 50 parallel to the X-Y plane (refer to Figure 2 Processes 2 to 3). According to this structure, a plurality of precursors of the graphite composite 103 can be obtained from a large block. Furthermore, a plurality of graphite composites 103 can be efficiently manufactured from the precursor.

[0095] The specific process of the cutting process is not particularly limited. For example, cutting using a wire saw, cutting using a die, and cutting using a laser can be cited. From the advantages of obtaining productivity, among them, cutting using a wire saw is more preferable.

[0096] The metal layer forming process is a process of forming a first metal layer 3 and a second metal layer 4 on the first main surface 30 and the second main surface 31 of the anisotropic graphite laminate 1 on which the reinforcement layer 10 is formed (refer to Figure 2 Process 4).

[0097] In the above-mentioned metal layer forming process, it is preferable to form the first metal layer 3 and the second metal layer 4 simultaneously. According to this configuration, a graphite composite can be efficiently manufactured.

[0098] In the foregoing metal layer forming step, the first metal layer 3, the second metal layer 4, the third metal layer 5, and the fourth metal layer 6 can be formed simultaneously. Further, in the foregoing metal layer forming step, in addition to the first metal layer 3 to the fourth metal layer 6, the fifth metal layer 7 can also be formed simultaneously. According to this configuration, a graphite composite that can better prevent graphite powder from peeling off from the anisotropic graphite laminate 1 can be manufactured efficiently.

[0099] The method for forming the first metal layer 3, the second metal layer 4, the third metal layer 5, the fourth metal layer 6, and the fifth metal layer 7 is not particularly limited, and known methods can be appropriately used according to the raw materials of these metal layers. As such a method, for example, plating treatment, pasting of a metal thin film with an adhesive, metal evaporation plating, and sputtering treatment can be cited. According to this configuration, on the structure of the anisotropic graphite laminate 1 and the like, metal layers such as the first metal layer 3 and the second metal layer 4 can be directly formed.

[0100] When a metal layer (for example, the first metal layer 3, the second metal layer 4, the third metal layer 5, the fourth metal layer 6, the fifth metal layer 7) is formed on the anisotropic graphite laminate 1 by plating treatment or the like and then the reinforcing layer 10 is provided on the anisotropic graphite laminate 1, when the anisotropic graphite laminate 1 is subjected to plating treatment, it needs to be placed in an electroplating bath in a state of being held by a holding tool. At this time, at the portion of the surface of the anisotropic graphite laminate 1 that contacts the holding member, a portion where the metal layer is not formed easily occurs. In this case, the graphite powder easily peels off from the anisotropic graphite laminate 1. Further, due to vibrations generated during the formation of the metal layer, the anisotropic graphite laminate 1 is easily broken.

[0101] By performing the metal layer forming step after the reinforcing step, the above problems can be solved.

[0102] The manufacturing method of the graphite composite 103 according to an embodiment of the present invention may further include an anisotropic graphite laminate manufacturing step of manufacturing the anisotropic graphite laminate 1.

[0103] The anisotropic graphite laminate manufacturing step may include a laminating step of alternately laminating graphite sheets and resin layers to form a laminate. The foregoing laminating step is as follows: When the crystal orientation plane of the graphite layer of the graphite sheet is arranged parallel to the X-Z plane, the graphite sheet and the resin layer are alternately laminated in a state where their surfaces overlap in a direction perpendicular to the foregoing surface and intersecting the Y axis to form a laminate.

[0104] As a specific method of the laminating step, the following can be cited: (i) a method of alternately laminating graphite sheets and resin layers; (ii) a method of forming a graphite adhesive sheet by disposing a resin layer on at least one surface of a graphite sheet and then laminating a plurality of such graphite adhesive sheets.

[0105] The manufacturing process of the anisotropic graphite laminate preferably further includes an adhesion process of forming the anisotropic graphite laminate 1 by thermally fusing the graphite sheets and the resin layer by heating the laminate.

[0106] <Summary>

[0107] One embodiment of the present invention includes the following components.

[0108] 〔1〕A graphite composite, comprising:

[0109] An anisotropic graphite laminate, in the case where three mutually orthogonal spatial axes are set as the X-axis, the Y-axis orthogonal to the X-axis, and the Z-axis perpendicular to the X-Y plane, the anisotropic graphite laminate is formed by laminating a plurality of graphite sheets in the Y-axis direction with a resin layer interposed therebetween, and the crystal orientation plane of the graphite layer is arranged parallel to the X-Z plane, having a first main surface parallel to the X-Y plane and a second main surface on the opposite side of the first main surface;

[0110] A first metal layer provided on the first main surface of the aforementioned anisotropic graphite laminate;

[0111] A second metal layer provided on the second main surface of the aforementioned anisotropic graphite laminate; and

[0112] A reinforcing layer provided on at least one surface of the surface parallel to the Y-Z plane of the aforementioned anisotropic graphite laminate,

[0113] The thicknesses of the aforementioned first metal layer and the aforementioned second metal layer are respectively 2 μm to 50 μm.

[0114] 〔2〕The graphite composite according to 〔1〕, wherein the thickness of the aforementioned reinforcing layer is respectively 50 μm to 500 μm.

[0115] 〔3〕The graphite composite according to 〔1〕 or 〔2〕, wherein the aforementioned first metal layer and the aforementioned second metal layer are in direct contact with the aforementioned anisotropic graphite laminate.

[0116] 〔4〕The graphite composite according to claim 3, wherein the aforementioned first metal layer and the aforementioned second metal layer contain at least one selected from the group consisting of copper, nickel, and gold.

[0117] 〔5〕The graphite composite according to any one of 〔1〕 to 〔4〕, wherein the thickness of the aforementioned anisotropic graphite laminate in the Z-axis direction is 0.30 mm to 5.0 mm.

[0118] 〔6〕The graphite composite according to any one of 〔1〕 to 〔5〕, wherein the aforementioned reinforcing layer contains at least one selected from the group consisting of resin, metal, and ceramic.

[0119] 〔7〕The graphite composite according to any one of 〔1〕to 〔6〕, wherein the reinforcing layer is provided on two surfaces parallel to the Y-Z plane of the anisotropic graphite laminate.

[0120] 〔8〕The graphite composite according to 〔7〕, wherein a fifth metal layer is respectively provided on the reinforcing layer, and the reinforcing layer is provided on two surfaces parallel to the Y-Z plane of the anisotropic graphite laminate.

[0121] 〔9〕The graphite composite according to any one of 〔1〕to 〔8〕, wherein a third metal layer and a fourth metal layer are respectively provided on two surfaces parallel to the X-Z plane of the anisotropic graphite laminate.

[0122] 〔10〕The graphite composite according to claim 9, wherein the third metal layer and the fourth metal layer are in direct contact with the anisotropic graphite laminate.

[0123] 〔11〕The graphite composite according to any one of 〔1〕to 〔10〕, wherein the resin layer contains at least one of a thermoplastic resin and a thermosetting resin, and the glass transition temperature of the resin layer is 50 °C or higher.

[0124] 〔12〕A method for manufacturing a graphite composite, the graphite composite comprising: an anisotropic graphite laminate, in a case where three mutually orthogonal space axes are set as the X axis, the Y axis orthogonal to the X axis, and the Z axis perpendicular to the X-Y plane, the anisotropic graphite laminate is formed by laminating a plurality of graphite sheets in the Y-axis direction with a resin layer interposed therebetween, and the crystal orientation plane of the graphite layer is arranged parallel to the X-Z plane, and having a first main surface parallel to the X-Y plane and a second main surface opposite to the first main surface,

[0125] The method for manufacturing the graphite composite includes:

[0126] A reinforcing step of forming a reinforcing layer on at least one surface of the surfaces parallel to the Y-Z plane of the anisotropic graphite laminate; and

[0127] A metal layer forming step of forming a first metal layer and a second metal layer on the first main surface and the second main surface of the anisotropic graphite laminate on which the reinforcing layer is formed,

[0128] The thicknesses of the first metal layer and the second metal layer are respectively 2 μm to 50 μm.

[0129] 〔13〕The method for manufacturing a graphite composite according to 〔12〕, which includes, after the reinforcing step and before the metal layer forming step: a cutting step of cutting the reinforcing layer and the anisotropic graphite laminate.

[0130] 〔14〕The manufacturing method of the graphite composite according to 〔12〕or 〔13〕, wherein in the aforementioned metal layer forming step, the aforementioned first metal layer and the aforementioned second metal layer are formed simultaneously.

[0131] 〔15〕The manufacturing method of the graphite composite according to any one of 〔12〕to 〔14〕, wherein the aforementioned resin layer contains at least any one of a thermoplastic resin and a thermosetting resin, and the glass transition temperature of the aforementioned resin layer is 50°C or higher.

[0132] 〔16〕The graphite composite according to any one of 〔1〕to 〔11〕, wherein the thicknesses of the aforementioned resin layers are each 100 μm or less.

[0133] 〔17〕The graphite composite according to any one of 〔1〕to 〔11〕, wherein the thickness of the aforementioned graphite sheet is 2 μm to 50 μm.

[0134] 〔18〕The graphite composite according to any one of 〔1〕to 〔11〕, wherein the thermal conductivities in the X-axis direction and the Z-axis direction of the aforementioned anisotropic graphite laminate are 1000 W / mK or higher.

[0135] 〔19〕The graphite composite according to 〔9〕or 〔10〕, wherein the thicknesses of the third metal layer and the fourth metal layer are each 2 μm to 50 μm.

[0136] 〔20〕The graphite composite according to any one of 〔1〕to 〔11〕, wherein an adhesive layer is provided between the aforementioned anisotropic graphite laminate and the aforementioned reinforcing layer.

[0137] 〔21〕The graphite composite according to 〔20〕, wherein the thicknesses of the aforementioned adhesive layers are each 5 μm to 500 μm.

[0138] 〔22〕The graphite composite according to any one of 〔1〕to 〔11〕, which has a reinforcing layer provided on at least one surface of the surfaces parallel to the X-Z plane of the aforementioned anisotropic graphite laminate.

[0139] 〔23〕The graphite composite according to 〔8〕, wherein the thickness of the fifth metal layer is 2 μm to 50 μm.

[0140] Examples

[0141] Hereinafter, one embodiment of the present invention will be described in more detail by way of examples and comparative examples, but the present invention is not limited to these.

[0142] <Manufacture of Anisotropic Graphite Laminate and Graphite Composite>

[0143] (Graphite Composite (A-1): Example 1)

[0144] A graphite sheet (referred to as GS1) with a thickness of 36 μm, a thermal conductivity in the plane direction of 1650 W / mK, and a density of 2.0 g / cm 2 obtained by heat-treating a polyimide film.

[0145] GS1 with a size of 100 mm × 100 mm and a polyester film (thickness 5 μm, dielectric constant 3.2, melting point 260 °C) were alternately laminated in such a way that the number of GS1 sheets became 1097. For the obtained laminate, a pressure of 0.5 MPa was applied for 1 minute using a press heated to 250 °C to produce a graphite laminate block (100 mm × 100 mm, thickness 45 mm). In addition, the laminate was performed in such a way that the uppermost and lowermost layers of the graphite laminate block were graphite sheets.

[0146] The obtained graphite laminate block (100 mm × 100 mm, thickness 45 mm) was cut with a wire saw to obtain an anisotropic graphite laminate 1. For the size of the anisotropic graphite laminate 1, when the crystal orientation plane of the anisotropic graphite laminate 1 was arranged parallel to the X-Z plane, the length of the side parallel to the X-axis was 39.53 mm, the length of the side parallel to the Y-axis was 29.99 mm, and the length of the side parallel to the Z-axis was 80 mm.

[0147] Next, on two surfaces of the anisotropic graphite laminate 1 parallel to the Y-Z plane, an oxygen-free copper with a size of 29.99 mm × 80 mm × 150 μm as the reinforcing layer 10 was bonded by means of a bonding tape of 29.99 mm × 80 mm × 85 μm as the bonding layer 11 (using a heat-resistant double-sided tape API214A-50X10 manufactured by CHUKOH CHEMICAL INDUSTRIES, LTD. cut to an appropriate size).

[0148] Then, the composite was cut parallel to the X-Y plane with a wire saw to obtain a composite of any thickness. The obtained composite was subjected to a plating treatment to deposit 5 μm thick nickel on the surface, thereby obtaining a graphite composite (A-1) with a metal coating (corresponding to the first metal layer 3 and the second metal layer 4).

[0149] In Figure 3 the central figure of the three figures shown in 301, a schematic of the structure of the graphite composite (A-1) is shown, and the dimensions of the graphite composite (A-1) are described below:

[0150] · The size of the X-Y plane of the anisotropic graphite laminate 1: 39.53 mm × 29.99 mm,

[0151] · The thickness of the anisotropic graphite laminate 1 in the Z-axis direction: 0.99 mm,

[0152] · Thickness of the first metal layer 3 and the second metal layer 4 in the Z-axis direction: 5 μm,

[0153] · Thickness of the adhesive layer 11 in the X-axis direction: 85 μm,

[0154] · Thickness of the adhesive layer 11 in the Z-axis direction: 0.99 mm,

[0155] · Thermal conductivity of the adhesive layer 11: 0.2 W / mK,

[0156] · Thickness of the reinforcing layer 10 in the X-axis direction: 150 μm,

[0157] · Thickness of the reinforcing layer 10 in the Z-axis direction: 0.99 mm.

[0158] (Graphite composite (A-2): Example 2)

[0159] Similar to the above graphite composite (A-1), a graphite sheet (GS1) with a thickness of 36 μm, a in-plane thermal conductivity of 1650 W / mK, and a density of 2.0 g / cm 2 obtained by heat-treating a polyimide film was used. A bonding sheet (manufactured by DIC Corporation, #8602TNW-05, thickness 5 μm) was laminated on one side of the GS1 with a size of 100 mm × 100 mm, and 1097 laminated GS1s were stacked in such a way that the GS1 surface was in contact with the bonding surface of the bonding sheet. A pressure of 0.5 MPa was applied to the obtained laminate for 1 minute to produce a graphite laminate block (100 mm × 100 mm, thickness 45 mm). It should be noted that only the uppermost 1 piece of GS1 without the laminated bonding sheet was used. Then, the obtained graphite laminate block was cut with a wire saw to obtain a graphite laminate 2. For the dimensions of the anisotropic graphite laminate 2, when the crystal orientation plane of the anisotropic graphite laminate 2 was arranged parallel to the X-Z plane, the length of the side parallel to the X-axis was 39.53 mm, the length of the side parallel to the Y-axis was 29.99 mm, and the length of the side parallel to the Z-axis was 80 mm.

[0160] Next, on the two surfaces of the anisotropic graphite laminate 2 parallel to the Y-Z plane, an oxygen-free copper with a size of 29.99 mm × 80 mm × thickness 150 μm as the reinforcing layer 10 was bonded by means of a bonding tape of 29.99 mm × 80 mm × 85 μm as the adhesive layer 11 (using a heat-resistant double-sided tape API214A-50X10 manufactured by CHUKOH CHEMICAL INDUSTRIES, LTD. cut to an appropriate size).

[0161] The obtained composite is subjected to a plating treatment to deposit nickel with a thickness of 5 μm on the surface, thereby obtaining a graphite composite (A-2) with a metal coating (corresponding to the first metal layer 3 and the second metal layer 4).

[0162] The structure and dimensions of the graphite composite (A-2) are the same as those of the graphite composite (A-1).

[0163] (Graphite composite (B): Comparative Example 1)

[0164] The graphite laminate (90 mm × 90 mm, thickness 45 mm) produced in the above-mentioned "Graphite composite (A-1)" column is cut with a wire saw to obtain an anisotropic graphite laminate 3. For the dimensions of the anisotropic graphite laminate 3, when the crystal orientation plane of the anisotropic graphite laminate 3 is arranged parallel to the X-Z plane, the length of the side parallel to the X-axis is 40 mm, the length of the side parallel to the Y-axis is 30 mm, and the length of the side parallel to the Z-axis is 0.68 mm. It should be noted that the length of the side parallel to the Y-axis can be adjusted arbitrarily during cutting, and from the perspective of ease of cracking, it is preferably 0.5 mm or more.

[0165] Next, on the upper and lower surfaces (both surfaces parallel to the X-Y plane) of the anisotropic graphite laminate 1 arranged parallel to the X-Z plane as described above, an acrylic adhesive with a size of 40 mm × 30 mm × 10 μm as the adhesive layer 11 is overlapped, and then, outside each adhesive layer 11, oxygen-free copper with a size of 40 mm × 30 mm × a thickness of 150 μm as the reinforcing layer 10 is overlapped. By this method, a composite (B) with a length of the side parallel to the X-axis of 40 mm, a length of the side parallel to the Y-axis of 30 mm, and a length of the side parallel to the Z-axis of 1 mm is obtained.

[0166] Figure 3 The left figure among the three figures shown in 301 represents a schematic of the structure of the graphite composite (B), and the dimensions of the graphite composite (B) are described below:

[0167] · Dimensions of the X-Y plane of the anisotropic graphite laminate 1: 40 mm × 30 mm,

[0168] · Thickness of the anisotropic graphite laminate 1 in the Z-axis direction: 0.68 mm,

[0169] · Thickness of the adhesive layer 11 in the Z-axis direction: 10 μm,

[0170] · Thermal conductivity of the adhesive layer 11: 0.2 W / mK,

[0171] · Thickness of the reinforcing layer 10 in the Z-axis direction: 150 μm.

[0172] (Copper plate (C): Comparative Example 2)

[0173] Figure 3 The right - hand side of the three figures shown in 301 shows a schematic of the structure of the copper plate (C) (copper plate 15), and the dimensions of the copper plate (C) are described below:

[0174] · Thickness of the copper plate (C) in the X - axis direction: 40 mm,

[0175] · Thickness of the copper plate (C) in the Z - axis direction: 1.0 mm,

[0176] · Thickness of the copper plate (C) in the Y - axis direction: 30 mm.

[0177] <Evaluation of heat transfer performance>

[0178] The heat transfer performance of the above - mentioned graphite composites (A - 1), graphite composites (A - 2), graphite composite (B), and copper plate (C) was evaluated.

[0179] It should be noted that for the thermal conductivity of the anisotropic graphite laminate, the value in the direction parallel to the crystal orientation plane is 1450 W / mK, and the value in the direction perpendicular to the crystal orientation plane is 1 W / mK.

[0180] In addition, it was confirmed that the glass transition temperature of the resin layer of the anisotropic graphite laminate fabricated by the method described in the item "graphite composite (A - 1)" was 50 °C or higher, and the glass transition temperature of the resin layer of the anisotropic graphite laminate fabricated by the method described in the item "graphite composite (A - 2)" was 50 °C or higher. Here, the glass transition temperature was measured by DSC - 50 manufactured by Shimadzu Corporation at a heating rate of 1 °C / min.

[0181] Figure 3 302 shows a schematic of the evaluation method of the thermal conductivity. As Figure 3 shown in 302, a heat source 100 (150 W, 10 mm×20 mm), an adhesive 110 (TIM1 (t = 0.2 mm), 5 W / mK), a test sample 120 (graphite composite (A - 1), (A - 2), graphite composite (B), or copper plate (C)), a solder layer 130 (t = 0.05 mm, 40 W / mK), and a copper plate 140 (100 mm×100 mm, t = 0.5 mm) were arranged in sequence from above, and a heat transfer coefficient 150 (heat transfer coefficient: 10 KW / m 2 K, ambient temperature: 50 °C) was set on the lower side of the copper plate 140. It should be noted that here t represents the thickness.

[0182] In addition, each test sample 120 was arranged as Figure 3The two surfaces parallel to the X-Y plane shown in 301 are respectively in contact with the adhesive 110 or the solder layer 130.

[0183] In short, a thermal simulation system (using Solidworks) was fabricated in which the test sample 120 was inserted between the heat source 100 and the copper plate 140 with the aid of the adhesive 110 and the solder layer 130. The heat transfer coefficient 150 was set on the lower side of the copper plate 140 on the side opposite to the solder layer 130, and heat insulation was provided for the areas other than the lower side of the copper plate 140. The heat generation amount of the heat source 100 was 150 W, the outside air temperature was 50 °C, and the heat transfer coefficient was 10000 W / m 2 K, and the maximum temperature of the heat source 100 was measured.

[0184] It should be noted that in the case of this test, the heat of the heat source 100 dissipates to the environment with a heat transfer coefficient of 150 through the test sample 120. Therefore, the higher the heat diffusion ability of the test sample 120, the lower the maximum temperature of the heat source 100 becomes.

[0185] As a result of the measurement, in the tests using the graphite composite (A-1) (Example 1) and the graphite composite (A-2) (Example 2), the maximum temperature of the heat source 100 was 106 °C, in the test using the graphite composite (B) (Comparative Example 1), the maximum temperature of the heat source 100 was 145 °C, and in the test using the copper plate (C) (Comparative Example 2), the maximum temperature of the heat source 100 was 112 °C.

[0186] That is, it was clarified that the graphite composites (A-1) and (A-2) of the embodiments of the present invention have excellent heat diffusion ability, efficiently dissipate the heat of the heat source 100, and efficiently reduce the temperature of the heat source 100.

[0187] <Evaluation of Strength>

[0188] The following were used: (a) the structure of only the anisotropic graphite laminate 1 included in the graphite composite (A-1) manufactured in Example 1, (b) the structure of only the anisotropic graphite laminate 1, the adhesive layer 11, and the reinforcing layer 10 included in the graphite composite (A-1), and (c) the graphite composite (A-1). It should be noted that the structure of (c) above further includes a metal film (the first metal layer 3, the second metal layer 4, the third metal layer 5, the fourth metal layer 6, and the fifth metal layer 7) in addition to the structure of (b) above.

[0189] For each of the above structures (a) to (c), a three-point bending test was performed using a three-point bending device (manufactured by IMADA Co., Ltd.) at 50 mm / min, and the stress at the moment when each of (a) to (c) broke was measured.

[0190] The results of the tests were as follows. The structure of (a) fractured under a stress of approximately 3 N, the structure of (b) fractured under a stress of approximately 13 N, and the structure of (c) fractured under a stress of approximately 15 N to 16 N.

[0191] Using the structure of only the anisotropic graphite laminate 2 contained in the (a) graphite composite (A-2) manufactured in Example 2, the structure of only the anisotropic graphite laminate 2, the adhesive layer 11, and the reinforcing layer 10 contained in the (b) graphite composite (A-2), and (c) the graphite composite (A-2), in addition, a metal layer identical to the above evaluation method was formed, and a three-point bending test was conducted using the same test method to measure the stress at which each of the structures of (a) to (c) fractured.

[0192] The results of the tests were that the structure of (a) fractured under a stress of approximately 4 N, the structure of (b) fractured under a stress of approximately 13 N, and the structure of (c) fractured under a stress of approximately 16 N to 17 N.

[0193] That is, it was clarified that the fracture susceptibility of the anisotropic graphite laminate of the graphite composite of the embodiment of the present invention was improved.

[0194] Industrial Applicability

[0195] The present invention can be used for heat transfer elements, and more specifically, can be used for heat transfer elements used in electronic devices and electronic components.

[0196] Explanation of Reference Numerals

[0197] 1 Anisotropic graphite laminate

[0198] 3 First metal layer

[0199] 4 Second metal layer

[0200] 5 Third metal layer

[0201] 6 Fourth metal layer

[0202] 7 Fifth metal layer

[0203] 10 Reinforcing layer

[0204] 11 Adhesive layer

[0205] 15 Copper plate

[0206] 20 Crystal orientation plane

[0207] 30 First main surface

[0208] 31 Second main surface

[0209] 50 Cutting surface

[0210] 100 Heat source

[0211] 103 Graphite composite

[0212] 110 Adhesive

[0213] 120 Test sample

[0214] 130 Solder layer

[0215] 140 Copper plate

[0216] 150 Heat transfer coefficient

Claims

1. A graphite composite, comprising: An anisotropic graphite laminate, in a case where three mutually orthogonal spatial axes are defined as an X-axis, a Y-axis orthogonal to the X-axis, and a Z-axis perpendicular to the X-Y plane, the anisotropic graphite laminate is formed by laminating a plurality of graphite sheets in the Y-axis direction with a resin layer interposed therebetween, and the crystal orientation plane of the graphite layer is arranged parallel to the X-Z plane, having a first main surface parallel to the X-Y plane and a second main surface on the opposite side of the first main surface; A first metal layer provided on the first main surface of the anisotropic graphite laminate; A second metal layer provided on the second main surface of the anisotropic graphite laminate; and A reinforcing layer provided on at least one surface parallel to the Y-Z plane of the anisotropic graphite laminate, The thicknesses of the first metal layer and the second metal layer are each 2 μm to 50 μm.

2. The graphite composite according to claim 1, wherein, The thickness of the reinforcing layer is 50 μm to 500 μm.

3. The graphite composite according to claim 1, wherein, The first metal layer and the second metal layer are in direct contact with the anisotropic graphite laminate.

4. The graphite composite according to claim 3, wherein, The first metal layer and the second metal layer contain at least one selected from the group consisting of copper, nickel, and gold.

5. The graphite composite according to claim 1, wherein, The thickness of the anisotropic graphite laminate in the Z-axis direction is 0.30 mm to 5.0 mm.

6. The graphite composite according to claim 1, wherein, The reinforcing layer contains at least one selected from the group consisting of resin, metal, and ceramic.

7. The graphite composite according to claim 1, wherein The reinforcing layer is provided on two surfaces parallel to the Y-Z plane of the anisotropic graphite laminate.

8. The graphite composite according to claim 7, wherein, A fifth metal layer is respectively provided on the reinforcing layer, and the reinforcing layer is provided on two surfaces parallel to the Y-Z plane of the anisotropic graphite laminate.

9. The graphite composite according to claim 1, wherein, A third metal layer and a fourth metal layer are respectively provided on two surfaces parallel to the X-Z plane of the anisotropic graphite laminate.

10. The graphite composite according to claim 9, wherein, The third metal layer and the fourth metal layer are in direct contact with the anisotropic graphite laminate.

11. The graphite composite according to claim 1, wherein, The resin layer contains at least one of a thermoplastic resin and a thermosetting resin, The glass transition temperature of the resin layer is 50 °C or higher.

12. A method for manufacturing a graphite composite, the graphite composite comprising: an anisotropic graphite laminate, in a case where three mutually orthogonal spatial axes are defined as an X-axis, a Y-axis orthogonal to the X-axis, and a Z-axis perpendicular to the X-Y plane, the anisotropic graphite laminate is formed by laminating a plurality of graphite sheets in the Y-axis direction with a resin layer interposed therebetween, and the crystal orientation plane of the graphite layer is arranged parallel to the X-Z plane, having a first main surface parallel to the X-Y plane and a second main surface on the opposite side of the first main surface, The manufacturing method includes: A reinforcing step of forming a reinforcing layer on at least one surface parallel to the Y-Z plane of the anisotropic graphite laminate; And A metal layer forming step of forming a first metal layer and a second metal layer on the first main surface and the second main surface of the anisotropic graphite laminate on which the reinforcing layer is formed, The thicknesses of the first metal layer and the second metal layer are each 2 μm to 50 μm.

13. The method for manufacturing a graphite composite according to claim 12, comprising: Cutting step, after the reinforcing step and before the metal layer forming step, cutting the reinforcing layer and the anisotropic graphite laminate.

14. The method for manufacturing a graphite composite according to claim 12, wherein In the metal layer forming step, the first metal layer and the second metal layer are formed simultaneously.

15. The method for manufacturing a graphite composite according to claim 12, wherein The resin layer contains at least one of a thermoplastic resin and a thermosetting resin, The glass transition temperature of the resin layer is 50 °C or higher.

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