TW201536907A - Thermally conductive composite material, and manufacturing method therefor - Google Patents

Abstract

The purpose of the present invention is to provide a thermally conductive composite material that is low cost and achieves both high hardness and heat dissipating properties. A thermally conductive composite material (1) includes a fiber reinforced resin material (2) which is sheet shaped and contains a continuous reinforcing fiber (f), and metal foil layers (3(3a, 3b)) which are integrally joined to both surfaces of the fiber reinforced resin material (2), and the thickness (T1) of the thermally conductive composite material is 0.07-1mm. The thickness (t2) of the fiber reinforced resin material (2) is at least 0.05mm to less than 1mm, the thickness (t3a, t3b) of the metal foil layers (3(3a, 3b)) is 0.009-0.1mm, and the tensile elasticity of the thermally conductive composite material (1) is at least 80GPa.

Description

Thermal conductive composite material and method of manufacturing same

The present invention relates to a casing, a casing case or a mobile digital medical device for an information terminal machine represented by a smart phone, an input tablet, a portable computer, or the like, or as another motor case requiring heat countermeasures A thermally conductive composite material having high rigidity (high elasticity) and high heat dissipation characteristics, that is, thermal conductivity, and a method for producing the same.

In the information terminal equipment such as a smart phone, an input board, and a portable computer, a case, a case, and the like, and a case surface material, a top plate, etc. which are integrally attached to the case, etc. are mounted. A method of forming a plastic material to reduce the weight and making it has become mainstream. For example, the smart phone 100 having a schematic configuration shown in FIG. 1 is generally provided with a thin box-shaped case (or case case) 101 on which a battery, a circuit board, or the like is mounted, and is mounted on a case (or case case) 101. The cover 102 includes a display and a touch panel.

In recent years, in the above-mentioned information terminal equipment, as the processing performance of the CPU and the like are improved, the increase in the power consumption of the semiconductor device and the increase in the amount of heat generation are imperative, and therefore, the shell is further strongly required. Rigidity and heat dissipation (thermal conductivity) of the body (or case).

In the past, graphite sheets which are generally used as heat dissipating members have an amazing thermal conductivity. However, the price is extremely high and there is a problem with rigidity.

Therefore, Patent Document 1 proposes a heat dissipation plate in which a carbon fiber composite material is mixed in order to cool a heating element such as a semiconductor used in an integrated circuit. Since the carbon fiber composite material of the heat sink has an anisotropy of thermal conductivity, it is formed by joining a highly thermally conductive metal around a carbon fiber composite in which a heating element such as a semiconductor is mounted, and the carbon fiber of the carbon fiber composite is perpendicular to the surface on which the heating element is mounted. Ground single axis alignment.

Further, Patent Document 2 proposes a heat-conductive composite molded article in which an aluminum flat plate is attached to a bottom surface portion of a carbon fiber-reinforced plastic molded article as a casing of a computer incorporating a high-performance CPU, and the carbon fiber-reinforced plastic molded article has a box shape. Long fiber particles.

Patent Document 1: Japanese Patent Laid-Open Publication No. 2002-57259

Patent Document 2: Japanese Patent Laid-Open No. Hei 11-147286

As is understood from the description of the above-mentioned patent documents, carbon fibers, which are reinforcing fibers used in the carbon fiber reinforced composite material, transmit heat well in the fiber axis direction, but hardly transfer heat in a direction perpendicular to the fiber axis. Therefore, the carbon fiber near the surface of the heat source of the carbon fiber reinforced composite material contributes to heat diffusion to some extent, but the thermal conductivity is poor in the thickness direction of the carbon fiber reinforced composite material, so that the carbon fiber far from the inner side of the surface hardly diffuses heat. It helps. In other words, for example, the pitch-based carbon fiber itself has a thermal conductivity of 100 to 600 W/mK and exhibits an extremely high numerical value. However, there is a problem in that it exhibits an anisotropy only in the fiber axis direction and exhibits an anisotropy. In the case of a carbon fiber reinforced composite material produced by impregnating a resin with carbon fibers, the thermal conductivity of the resin is adversely affected, and the desired heat conduction characteristics and the like cannot be obtained.

In addition, the heat dissipating plate using the carbon fiber composite material described in the above-mentioned Patent Document 1 is configured, for example, by embedding a carbon fiber composite having a thickness of 2 mm in a central portion of a copper sheet having a thickness of 30 mm and a thickness of 2 mm, and the carbon fiber composite is bonded to the carbon fiber composite. A heating element is mounted on it. Further, in the carbon fiber reinforced plastic molded article described in Patent Document 2, for example, the thickness of the carbon fiber reinforced plastic molded article is 1.4 mm, the weight average fiber length of the long fiber particles is 0.38 mm, and the thickness of the aluminum flat plate is 0.6 mm.

The heat dissipating plate or the carbon fiber reinforced plastic molded article described in Patent Documents 1 and 2 cannot be used as a casing cover for a smart phone or the like, or a reinforcing plate for reinforcing the casing.

Therefore, the inventors of the present invention conducted a large number of research experiments in order to improve the above problems of the use of the above-described conventional carbon fiber composite material-mixed heat dissipation plate or carbon fiber reinforced plastic molded article, and as a result, it was found that the contact portion with the heat radiator was obtained. The surface is made of metal, and a fiber-reinforced composite material such as a carbon fiber reinforced composite material having a high rigidity is disposed inside, or a metal is disposed inside, and a fiber reinforced composite material such as a carbon fiber reinforced composite material is disposed on both sides thereof, and the metal is The thickness and the thickness of the fiber-reinforced composite material are optimized, whereby the thermal conductivity of the metal as the isotropic material can be promoted to the in-plane direction and thickness in the in-plane direction other than the fiber axis direction of the fiber-reinforced composite material. The direction maintains good heat dissipation characteristics (thermal conductivity) and ensures high rigidity.

That is, an object of the present invention is to provide a thermally conductive composite material which is low in cost and which can simultaneously achieve high rigidity and heat dissipation.

The above object is achieved by using the thermally conductive composite of the present invention. Briefly stated, in accordance with a first aspect of the present invention, there is provided a thermally conductive composite material having a continuous The sheet-like fiber-reinforced resin material of the reinforced fiber and the metal foil layer integrally bonded to both surfaces of the fiber-reinforced resin material have a thickness of 0.07 to 1 mm, and the thickness of the fiber-reinforced resin material is set to 0.05 mm or more. When the thickness is less than 1 mm, the thickness of the metal foil layer is set to 0.009 to 0.1 mm, and the tensile modulus of the thermally conductive composite material is 80 GPa or more.

According to a second aspect of the present invention, there is provided a thermally conductive composite material comprising a metal foil layer and a sheet-like fiber-reinforced resin material comprising continuous reinforcing fibers integrally bonded to both sides of the metal foil layer, the thickness being set to 0.12 The thickness of the fiber-reinforced resin material is set to 0.05 mm or more and less than 1 mm, and the thickness of the metal foil layer is set to 0.009 to 0.1 mm. The tensile elastic modulus of the thermally conductive composite material is less than 1 mm. The number is 80 GPa or more.

According to the first aspect of the present invention, the fiber-reinforced resin material contains 20% or more of the pitch-based carbon fiber having a thermal conductivity of the reinforcing fiber of 100 W/mK or more and 400 GPa or more in terms of fiber volume content. The tensile modulus of elasticity.

According to another aspect of the invention, the reinforced fiber of the fiber-reinforced resin material is a pitch-based carbon fiber, a PAN (polyacrylonitrile)-based carbon fiber or a glass fiber, or a mixture of two or more kinds of the fibers.

According to another embodiment of the first and second aspects of the present invention, the fiber-reinforced resin material is formed by continuously drawing the reinforcing fibers in one direction and impregnating the resin, and/or woven at least in the two-axis direction. The finished fabric is formed by impregnating a resin.

According to another embodiment of the first and second aspects of the present invention, the fiber-reinforced resin material is a sheet formed by continuously drawing the reinforcing fibers in one direction and impregnating the resin. The material is produced by laminating at least in the two-axis direction.

According to another embodiment of the first and second aspects of the invention, the metal foil layer is made of a metal having a thermal conductivity of 50 W/mK or more.

According to another embodiment of the invention described above, the thermally conductive composite material has a thickness of 0.12 to 0.5 mm.

According to a third aspect of the present invention, there is provided a method for producing a thermally conductive composite material having a metal foil layer integrated on both sides of a fiber-reinforced resin material, wherein the thermally conductive composite material has a sheet-like fiber reinforced resin containing continuous reinforcing fibers a material and a metal foil layer integrally bonded to both surfaces of the fiber-reinforced resin material, wherein the thickness of the thermally conductive composite material is set to 0.07 to 1 mm, and the tensile elastic modulus is 80 GPa or more, characterized in that: (a) preparation is continuous At least one prepreg sheet in which the reinforcing fibers are aligned at least in one direction and the resin is semi-hardened by impregnation of the resin to have a basis weight of 25 to 600 g/m ² and the fiber volume fraction is set to 20 to 70%. And a metal foil having a thickness of 0.009 to 0.1 mm, (b) pressing the metal foil on both sides of the prepreg sheet to integrally laminate the layer, and (c) thereafter curing the prepreg sheet Fiber-reinforced resin material.

According to a fourth aspect of the present invention, there is provided a method of producing a thermally conductive composite material having a fiber-reinforced resin material integrated on both sides of a metal foil layer, the thermally conductive composite material having a metal foil layer and integrally bonded to the metal foil layer a sheet-like fiber-reinforced resin material comprising continuous reinforcing fibers on both sides, the thickness of the thermally conductive composite material being 0.12 to 1 mm, and a tensile elastic modulus of 80 GPa or more, characterized in that: (a) preparation is continuous At least one prepreg sheet in which the reinforcing fibers are aligned in at least one direction and impregnated with resin to semi-harden the fiber basis weight is set to 25 to 600 g/m ² and the fiber volume fraction is set to 20 to 70%. And the metal foil having a thickness of 0.009 to 0.1 mm, (b) pressing the prepreg sheet on both surfaces of the metal foil to form a layer, and (c) thereafter, curing the prepreg sheet Fiber reinforced resin material.

According to the present invention, it is possible to prevent the internal damage of the device by preventing deformation due to a force other than the reinforcing body by attaching to the reinforcing body, and to diffuse without forming hot spots.

1‧‧‧ Thermally conductive composites

2‧‧‧Fiber reinforced resin materials

3‧‧‧metal foil layer

10‧‧‧Fiber-reinforced sheet

10PG‧‧‧Prepreg tablets

101‧‧‧Reinforced body

Fig. 1 is a perspective view showing a schematic configuration of a smart phone, showing a state in which a casing or a casing of a smart phone is reinforced by the thermally conductive composite material of the present invention.

2(a) is a schematic cross-sectional view showing a casing or a casing of a smart phone made of a reinforcing body reinforced by the thermally conductive composite material of the present invention, and FIG. 2(b) is a thermal composite of the present invention. A schematic cross-sectional view of an embodiment of a material. 2(c) is an enlarged cross-sectional view showing a schematic configuration of another embodiment of the thermally conductive composite material of the present invention.

Fig. 3(a) is a perspective view showing an embodiment of a prepreg sheet (fiber-reinforced resin material) and a reinforcing fiber sheet before joining a metal foil layer, and Fig. 3(b) is a view showing a layered state of a prepreg sheet. A diagram of an example.

4(a) and 4(b) are schematic structural views showing a method of producing a thermally conductive composite material of the present invention.

5(a) and 5(b) are respectively a plan view and a cross-sectional view for describing the dimensional shape of a test sample of a thermally conductive composite material, and FIG. 5(c) is a temperature measuring method for testing the heat dissipation property of the test sample. Figure.

Hereinafter, the thermally conductive composite material of the present invention will be described in detail based on the drawings.

Example 1

As described above, FIG. 1 shows a schematic configuration of the smart phone 100, and shows that the casing or the casing of the smart phone 100 is reinforced by the reinforcing plate formed by the thermally conductive composite material 1 of the present invention (ie, the reinforcing body is reinforced) The aspect of the bottom plate portion 101a of 101).

Fig. 2 (a) is a cross-sectional view showing a schematic configuration of a casing or a casing 101 of a smartphone made of a reinforcing body reinforced by the thermally conductive composite material 1 of the present invention, and Fig. 2 (b) is a view of the present invention. An outline configuration of an embodiment of the thermally conductive composite material 1 is an enlarged cross-sectional view. Further, unlike FIG. 1, the bottom plate portion 101a of the reinforcing body 101 in FIG. 2(a) is shown above. Fig. 2 (c) is an enlarged cross-sectional view showing a schematic configuration of another embodiment of the thermally conductive composite material 1 of the present invention which will be described later as the second embodiment.

First, referring to FIG. 2(b), in the present embodiment, the thermally conductive composite material 1 of the present invention has a sheet-like fiber-reinforced resin material 2 containing continuous reinforcing fibers and integrally bonded to the fiber-reinforced resin material 2. Two-sided metal foil layer 3 (3a, 3b). According to the present invention, referring to FIG. 3, the reinforcing fiber f of the fiber-reinforced resin material 2 is basically realized by the thermal expansion of the thermally conductive composite material 1 by the fiber-reinforced resin material 2 and the metal foil layer 3. The thermal diffusion of the fiber axis direction (XX direction in FIG. 3) and the direction of the fiber axis direction of the reinforcing fiber f (orthogonal direction) (the direction of YY in FIG. 3) are thermally diffused by the metal foil layer 3.

Moreover, the heat dissipation property of the thermal conductive composite material 1 is made of the thermal conductive composite material 1 And the thickness of each of the constituent members 2, 3 is designed to be achieved. That is, in the present invention, the heat conduction in the thickness direction (the ZZ direction in FIG. 3) of the thermally conductive composite material 1 is achieved by the following configuration: the direction orthogonal to the reinforcing fibers f of the fiber-reinforced resin material 2 (Fig. In the case of 3, the thermal conductivity of the YY direction is less likely to affect the composition of the fiber-reinforced resin material 2 and the metal foil layer 3.

That is, referring to Fig. 2(b) showing an embodiment of the present invention, the thickness (T1) of the thermally conductive composite material 1 is set to 1 mm or less, and usually 0.07 to 1 mm (0.07 mm ≦ T1 ≦ 1 mm). When the thickness (T1) exceeds 1 mm, as in the case of the present embodiment, when the thermally conductive composite material 1 is used as a reinforcing plate of a casing (or casing case) 101 of a smart phone as a reinforcing body, In order to accommodate the main components of the smart phone, the housing of the smart phone as the body 101 to be reinforced will inevitably increase, and the total weight will also increase, which will damage the miniaturization. Lightweight. In addition, when the thickness (T1) is less than 0.07 mm, it is difficult to achieve the high rigidity of the reinforcing plate which is the object of the present invention, and the fiber-reinforced resin material 2 and the metal foil layer 3 are extremely thin and cannot be used. The production of raw materials leads to higher costs. The thickness (T1) of the thermally conductive composite material 1 is preferably set to 0.12 to 0.5 mm.

Moreover, according to the results of an experimental study by the inventors of the present invention, it is understood that the thermal elastic composite material 1 needs to have a tensile elastic modulus set to obtain a desired tensile rigidity (tensile elastic modulus x cross-sectional area). It is at least 80 GPa or more larger than the tensile modulus of elasticity (70 GPa) of aluminum. If the tensile modulus of elasticity is less than 80 GPa, sufficient rigidity for reinforcement cannot be obtained.

Hereinafter, each constituent member of the thermally conductive composite material 1 of the present invention will be described in detail.

(fiber reinforced resin material)

The thickness (t2) of the sheet-like fiber-reinforced resin material 2 is set to 0.05 mm or more. When the thickness (t2) is 1 mm or more, the heat dissipation property is deteriorated. If the thickness (t2) is less than 0.05 mm, it is difficult to achieve high rigidity as a reinforcing plate. Further, the fiber-reinforced resin material 2 is extremely thin and cannot be produced by using a conventional raw material, resulting in problems such as an increase in cost. The thickness (t2) of the fiber-reinforced resin material 2 is preferably set to 0.1 to 0.46 mm.

The fiber-reinforced resin material 2 is made into a fiber-reinforced composite material containing 20% or more of pitch-based carbon fiber in terms of fiber volume fraction (Vf), and the thermal conductivity of the pitch-based carbon fiber is set to 100 W/mK or more, and the tensile elastic modulus is set. Set to 400GPa or more. The details are described below. In the present invention, the fiber volume fraction (Vf) is set to 20 to 70%, preferably 40 to 65%. In other words, in the case of using pitch-based carbon fibers, the tensile modulus of elasticity of the fiber-reinforced resin material 2 having a fiber volume fraction of 20% is set to 400 GPa × fiber volume content (Vf) 20% = 80 GPa. In other words, in the case where the pitch-based carbon fiber is used as the reinforcing fiber in the fiber-reinforced resin material 2, the maximum thermal conductivity (heat dissipation) and rigidity are obtained. By using the fiber-reinforced resin material 2 having such a constitution, the thermally conductive composite material 1 having a tensile modulus of elasticity of 80 GPa or more according to the present invention can be obtained.

The fiber-reinforced resin material 2 is produced by impregnating the resin R with the continuous reinforcing fiber f, and the carbon fiber can be optimally used as the reinforcing fiber f. In particular, as described above, the pitch-based carbon fiber is preferable. According to the required reinforcing plate, that is, the thermal conductive composite material 1, the PAN-based carbon fiber which is inferior to the pitch-based carbon fiber in terms of tensile modulus and thermal conductivity can be used. Further, depending on the case, in addition to the use of carbon fibers, it is also possible to use glass fibers which are inferior to carbon fibers in terms of tensile modulus and thermal conductivity. Of course, these fibers can also be used in combination.

Here, the tensile elastic modulus of the reinforcing fiber which can be used in the present invention is shown. And thermal conductivity, as shown in Table 1.

Further, as shown in Fig. 3 (a), the fiber-reinforced resin material 2 which can be used in the present invention is produced by using the prepreg sheet 10PG produced by the method of impregnating the resin R in the direction of the fiber axis. The reinforced fiber f as described above is drawn in one direction and formed into a sheet-like reinforcing fiber sheet 10S, and is semi-cured (B-staged).

When the fiber basis weight of the prepreg sheet 10PG is preferably 25 to 600 g/m ² , the fiber volume fraction (Vf) of the carbon fiber is set to 20% or more as described above. The prepreg sheet 10PG may be laminated in a plurality of sheets as needed. After the prepreg sheet 10PG is cured, the fiber-reinforced resin material 2 having a thickness (t2) of 0.05 mm or more and less than 1 mm, preferably 0.1 to 0.46 mm is formed as described above.

In the above description, the UD shape prepared by aligning the reinforcing fibers f in one direction has been described. Alternatively, a plurality of prepreg sheets 10PG may be laminated so that the reinforcing fibers f cross each other. In other words, the UD-shaped prepreg sheet 10PG produced by laminating the reinforcing fibers f in one direction can be laminated in at least two axial directions in the direction of the reinforcing fibers f and, if necessary, in the three-axis and four-axis directions. . For example, as shown in Fig. 3(b), the prepreg sheet 10PG (0°) in which the three reinforcing fibers f are aligned in the 0° direction and the prepreg sheet 10PG in which the reinforcing fibers f are aligned in the 90° direction can be used. (90°) and the prepreg sheet 10PG of the reinforcing fiber f aligned in the 0° direction (0°) produced by lamination. Further, although not shown, a prepreg sheet in which the reinforcing fiber f is aligned in the +45° direction and the prepreg sheet 10PG (+45°) and the reinforcing fiber f are aligned in the -45° direction may be used. 10PG (-45°) is formed in place of the three-axis of the prepreg sheet 10PG (90°) in which the reinforcing fibers f are aligned in the 90° direction, or may be used in the direction in which the reinforcing fibers f are aligned in the 90° direction. In addition to the impregnated sheet 10PG (90°), the prepreg sheet 10PG (+45°) in which the reinforcing fibers f are aligned in the +45° direction and the prepreg sheet 10PG in which the reinforcing fibers f are aligned in the -45° direction are used. 4-axis configuration of (-45°).

Further, the reinforcing fiber sheet 10S may be formed into a woven fabric (cloth) such as a plain weave, a twill weave, or a satin weave, which is formed by weaving one or more reinforcing fibers f. Further, the UD shape may be used in combination with the cloth.

As the impregnating resin (matrix resin) R, any of an epoxy resin, a vinyl ester resin, an MMA resin, an unsaturated polyester resin or a phenol resin is preferably used.

As described above, in the case of using pitch-based carbon fibers, the reinforcing fibers f in the fiber-reinforced resin material 2 are preferably contained in an amount of 20% or more in terms of fiber volume fraction (Vf). Usually set to 20~70%. When the fiber volume fraction (Vf) of the reinforcing fiber f is less than 20%, there is a problem that the amount of fiber is small and the required rigidity and heat dissipation property cannot be obtained. If it exceeds 70%, the resin is insufficient and the original resin cannot be obtained. Mechanical properties and other issues. The fiber volume fraction (Vf) is preferably in the range of 40 to 65%.

(metal foil layer)

The metal foil layer 3 (3a, 3b) is made of a metal having a thermal conductivity of 200 W/mK or more like aluminum or copper. Depending on the degree of heat dissipation required, for example, iron or nickel or brass having a thermal conductivity of 50 to 200 W/mK which is inferior to the metal materials may be used. Further, it may be made of an alloy of each of the above metals having an aluminum alloy of 50 to 200 W/mK. Metal foil The layers 3a and 3b may be made of the same metal depending on the shape of the thermally conductive composite material 1, and may be made of different metals.

Further, the thicknesses (t3a, t3b) of the metal foil layers 3 (3a, 3b) are respectively 0.009 to 0.1 mm (0.009 mm ≦ t3a, t3b ≦ 0.1 mm), and if the thickness (t3a, t3b) exceeds 0.1 mm, the metal The thickness (t3a, t3b) of the foil layer 3 (3a, 3b) is too thick, and the tensile elastic modulus of the fiber-reinforced resin material 2 does not occur, which is disadvantageous in terms of rigidity. Further, since the density of the metal foil layer 3 is generally higher than that of the fiber-reinforced resin material 2, the weight of the thermally conductive composite material 1 increases as the thickness (t3a, t3b) increases. If the thickness (t3a, t3b) is less than 0.009 mm, there is a problem that the cost cannot be increased by using existing raw materials. Further, since the material is too thin, it may be bent or broken, and the operation becomes extremely difficult. The thickness (t3a, t3b) of the preferred metal foil layer 3 (3a, 3b) is 0.01 to 0.05 mm, respectively. Further, depending on the shape of the thermally conductive composite material 1, the thicknesses (t3a, t3b) of the metal foil layers 3a and 3b may be the same or different.

(Production method)

According to the invention, the metal foil layer 3 (3a, 3b) must be integrally formed with respect to the fiber-reinforced resin material 2. That is, for example, as shown in Fig. 4(a), the metal foil layer 3 (3a, 3b) is pressed to the both sides of the so-called prepreg sheet 10PG which is impregnated with the reinforcing fiber sheet 10S and is not completely cured, and is formed by a volume layer. Heating is required to harden the resin R.

If the metal foil layer 3 (3a, 3b) is subsequently completely cured with the impregnating resin R of the prepreg sheet 10PG, that is, the fiber-reinforced resin material 2 is integrally formed by using an adhesive, it is worried. The heat dissipation or rigidity of the subsequent layer is lowered depending on the thickness of the adhesive. Further, it is difficult to perform the pre-substrate treatment of the metal foil layer 3 or to ensure the uniformity of the amount of the adhesive applied, or the front substrate treatment itself is complicated. In addition, the step of attaching is additionally generated and the cost is increased.

(reinforcing method)

The thermally conductive composite material 1 produced as described above is integrally joined to, for example, a smart phone case or a case (reinforcing body) 101 or the like (see FIG. 1).

In order to facilitate the work, a jig or the like is prepared, for example, by an adhesive, a double-sided tape or the like as a case, and is integrally joined to a top plate which is a preformed casing case or a top surface of the outer casing. In this case, heat dissipation or rigidity reduction does not occur by appropriately setting the thickness and material of the adhesive. Further, the smart body case or the case case 101 may be placed on the molding die at the time of molding, and may be integrally joined to the to-be-reinforced body 101 by press molding.

The reinforcing body 101 of the fiber-reinforced plastic product obtained as described above has a high rigidity and heat dissipation property as a thickness (T1) of 0.07 to 1 mm and a tensile modulus of elasticity of 80 GPa or more as described above. The heat-conductive composite material 1 is reinforced, whereby deformation due to an external force can be effectively prevented, and internal damage of the device can be prevented, and the hot spot caused by the heat radiation source housed inside the device can be prevented from being diffused.

(Explanation of experimental examples)

Then, in order to confirm the effect of the thermally conductive composite material 1 of the present invention, various test samples were prepared, and the mechanical strength and heat dissipation were tested for performance. The materials, compositions, and dimensions of the test samples used in the present experimental examples are shown in Tables 2 and 4, and the test results are shown in Tables 3 and 5.

(1) Experimental examples 1 to 4

(test sample)

In Experimental Example 1, a sheet-like aluminum (A5052) elemental substance (metal element) was used. In Experimental Example 2, a carbon fiber impregnated with resin in a cloth (fabric) of pitch-based carbon fiber Reinforced resin (CFRP cloth). In Experimental Example 3, a glass fiber reinforced resin (GFRP cloth) impregnated with a resin in a glass cloth (woven fabric) and a unidirectional carbon fiber sheet in which the pitch-based carbon fiber was aligned in one direction were impregnated with a resin. Carbon fiber reinforced resin (CFRP unidirectional) laminated glass-carbon fiber bonded composite (GFRP cloth - CFRP unidirectional). In Experimental Example 4, according to the constitution of the present invention, a fiber-reinforced composite material (metal foil surface layer-CFRP unidirectional core) produced by the following method was used: the copper foil was integrally molded to pull the pitch-based carbon fiber in one direction The unidirectional carbon fiber sheet is impregnated with both sides of a resin-coated carbon fiber reinforced resin (CFRP unidirectional).

Further, the pitch-based carbon fibers used in Experimental Examples 2, 3, and 4 used fiber bundles having an average diameter of 9 μm for monofilaments, 3,000, 6000, or 12,000 bundles, that is, pitch-based carbon fiber strands (Japan Graphite Fiber Co., Ltd.) Manufactured by the company (trade name: GRANOC XN-80), and impregnated with epoxy resin to obtain a prepreg.

The glass fiber cloth prepreg system used in Experimental Example 3 was manufactured using Mitsubishi Rayon Co., Ltd. (trade name: GHO250-381IM). The fiber basis weight is shown in Table 2.

In Experimental Example 3, a glass fiber cloth prepreg and a unidirectional carbon fiber sheet prepreg were laminated to form a single body, and then heated to cure the resin to prepare a test sample. Further, in Experimental Example 4, the copper foil was pressed onto both surfaces of the unidirectional carbon fiber sheet prepreg to form a laminate, and the resin was cured by heating to prepare the thermally conductive composite material 1.

The mechanical properties and thermal conductivity of the aluminum, copper, glass fiber, and pitch-based carbon fibers used are as follows.

Aluminum (A5052): Tensile modulus: 70GPa

Thermal conductivity: 138W/mK

Copper: Tensile modulus: 110~130GPa

Thermal conductivity: 398W/mK

Glass fiber: tensile modulus: 70GPa

Thermal conductivity: 0.5W/mK

Asphalt-based carbon fiber: tensile modulus: 780GPa

Thermal conductivity: 320W/mK

The test sample S used in Experimental Examples 1 to 4 has a length × width of 100 mm × 50 mm as shown in Figs. 5 (a) and (b), and a thickness dimension of each sample S (total thickness T1, thickness of the metal foil layer) T3, fiber reinforced resin material thickness t2) is shown in Table 2.

(heat dissipation)

The heat dissipation of each test sample S was measured as follows.

As shown in Fig. 5(c), a heater (H) is placed in the center portion in the width direction of the test sample, that is, the one end in the longitudinal direction of the test piece S (the left end in Fig. 5(c)), and temperature sensing is performed. The device (TS) measures at least the heater setting position of the test piece and the temperature measurement point on the opposite side (the right end in Fig. 5(c)) from the side on which the heater (H) is disposed. The temperature at the beginning of the temperature test and at the equilibrium state is measured. The judgment of the heat dissipation according to the result of the temperature measurement is as follows. That is, if the temperature of the point immediately below the heater is high, it is determined that the temperature is not dispersed to the surroundings, and thus the heat dissipation property is poor. Further, when the temperature of the measurement point at the other end of the test piece away from the heater (the right end in Fig. 5(c)) is raised, it is judged that the heat is dispersed to a distant place, so that the heat dissipation property is good.

The measurement results of the heat dissipation were as shown in Table 3. The temperature immediately below the heater of the sample of Experimental Example 1 was the lowest among Experimental Examples 1 to 4, and there was evidence that heat was diffused to the whole (◎: heat dissipation was very good). The sample of Experimental Example 2 was the third among Experimental Examples 1 to 4, although with Experimental Example 1. The sample was similarly diffused to the whole heat, but inferior to the sample of Example 1 (Δ). The temperature immediately below the heater of the sample of Experimental Example 3 was the highest among Experimental Examples 1 to 4, and heat was accumulated and heat was diffused only in one direction (×: poor heat dissipation). The temperature immediately below the heater of the sample of Experimental Example 4 was the second lowest among Experimental Examples 1 to 4, and it was seen that heat was diffused to the whole and the heat was diffused to the end of the test sample (◎~○: good heat dissipation).

(tensile elastic modulus, tensile rigidity)

The tensile elastic modulus (E), tensile rigidity, and weight were determined by calculation. The product of the tensile elastic modulus (E) of the tensile rigid sample and the cross-sectional area (A) of the sample (in the present embodiment, A = 50 mm × T1).

The results of tensile modulus, tensile rigidity and weight are shown in Table 3. According to Table 3, the test sample of Experimental Example 4 constituted by the present invention was excellent in heat dissipation and rigidity, and was also lighter in weight than the aluminum element of Experimental Example 1.

(2) Experimental example 5~9

In order to further confirm the effect of the thermally conductive composite material 1 of the present invention, the thickness (T1) of the thermally conductive composite material 1 was changed except for the experimental examples 1 to 4 described above, and the performance was tested by making the thickness uniform as much as possible. As described above, the materials, constitution, and dimensions of the test samples used in the experimental examples are shown in Table 4, and the test results are shown in Table 5.

(test sample)

In Experimental Example 5, a sheet-like aluminum A5052 elemental substance (metal element) was used. The thickness was set to 0.48 mm. In Experimental Example 6, a carbon fiber reinforced resin (CFRP unidirectional) obtained by laminating a prepreg impregnated with a resin in a unidirectional carbon fiber sheet in which the pitch-based carbon fibers were drawn in one direction in the X direction and the Y direction was used. 0°/90° plate). In Experimental Example 7, according to the configuration of the present invention, a fiber-reinforced composite material (metal foil surface layer-asphalt-based CFRP unidirectional 0°/90°) formed by integrally molding a copper foil on both surfaces of a carbon fiber-reinforced resin is used. The carbon fiber reinforced resin is impregnated with a resin in a unidirectional carbon fiber sheet in which the pitch-based carbon fibers are aligned in one direction. The dip is obtained by laminating layers in the X direction and the Y direction. In Experimental Example 8, a carbon fiber reinforced resin (PAN-based CFRP unidirectional 0°/90° plate) which was impregnated with a resin in a unidirectional carbon fiber sheet in which PAN-based carbon fibers were aligned in one direction was used. The prepreg is obtained by laminating layers in the X direction and the Y direction. In Experimental Example 9, according to the constitution of the present invention, a fiber-reinforced composite material (metal foil surface layer-PAN-based CFRP unidirectional 0°/90° plate) which is formed by integrally molding a copper foil on both surfaces of a carbon fiber reinforced resin is used. This carbon fiber reinforced resin is obtained by laminating a prepreg impregnated with a resin in a unidirectional carbon fiber sheet in which PAN-based carbon fibers are aligned in one direction in the X direction and the Y direction.

Further, the pitch-based carbon fibers, aluminum, and copper used in Experimental Examples 5 to 9 were the same as those in Experimental Examples 1 to 4. The PAN-based carbon fibers used in Experimental Examples 8 and 9 were manufactured by Mitsubishi Rayon Co., Ltd. (TR380G125, etc.). The total fiber basis weight used was set as shown in Table 4.

The test samples used in Experimental Examples 5 to 9 were set to have a length × width of 100 mm × 50 mm in the same manner as in Examples 1 to 4, and the thickness of each sample (total thickness T1, metal foil layer thickness t3, fiber reinforced resin material thickness) T2) is shown in Table 4.

(heat dissipation)

The heat dissipation of each test sample was measured by the same method as Experimental Examples 1 to 4.

The measurement results of heat dissipation are shown in Table 5. The temperature immediately below the heater of the sample of Experimental Example 5 was 38.8 ° C and the lowest among Experimental Examples 5 to 9, and the heat was further diffused to the whole (◎: heat dissipation). very good). The temperature immediately below the heater of the sample of Experimental Example 6 was 40 ° C and was the same as that of the aluminum of Experimental Example 5, although the signs of heat diffusion were diffused to the whole, but inferior. Aluminum in Experimental Example 5 (○: slightly better heat dissipation). The temperature immediately below the heater of the sample of Experimental Example 7 was 39.8 ° C, and the sign of heat diffusion by the effect of the copper foil was the same as that of the aluminum of Experimental Example 5 (◎: heat dissipation was very good). The temperature immediately below the heater of the sample of Experimental Example 8 was 93.4 ° C, and the heat was remarkably accumulated, and the heat was hardly diffused (×: poor heat dissipation). In the sample of Experimental Example 9, the temperature immediately below the heater was about 50 ° C, and heat storage was observed. However, when compared with the sample of Experimental Example 8, the heat storage was suppressed by the effect of the copper foil, and the heat was slightly diffused ( △: The heat dissipation is slightly worse).

(tensile elastic modulus, tensile rigidity)

The tensile modulus (E), tensile rigidity, and weight were determined by calculation in the same manner as in Experimental Examples 1 to 4. The results of tensile modulus, tensile rigidity and weight are shown in Table 5. According to Table 5, the test sample of Experimental Example 7 constructed according to the present invention is excellent in heat dissipation and rigidity, and is also lightweight in the aluminum alloy of Experimental Example 5 having a larger thickness in terms of weight.

Example 2

A second embodiment of the thermally conductive composite material 1 of the present invention is shown in Fig. 2(c). According to the present embodiment, the thermally conductive composite material 1 has the metal foil layer 3 and the sheet-like fiber-reinforced resin material 2 (2a, 2b) integrally bonded to both surfaces of the metal foil layer 3.

When the thermally conductive composite material 1 of the present embodiment is compared with the thermally conductive composite material 1 of the first embodiment, the fiber-reinforced resin material 2 (2a, 2b) having a high tensile modulus of elasticity is disposed. The structure of both surfaces of the metal foil layer 3 is more important than the heat dissipation property.

The thermally conductive composite material 1 of the present embodiment is different from the case of the first embodiment in that the sheet-like fiber-reinforced resin material 2 (2a, 2b) is integrally bonded to both surfaces of the metal foil layer 3, and the metal foil layer 3 as a constituent member is different. And sheet-like fiber reinforced resin material 2 (2a, 2b), set and The composition of Example 1 is the same as that of the material. Therefore, the description of the first embodiment will be omitted for the description of the metal foil layer 3 and the sheet-like fiber-reinforced resin material 2 (2a, 2b).

In the present embodiment, the thickness (T2) of the thermally conductive composite material 1 is set to be 1 mm or less as in the case of the above-described first embodiment, and is usually set to 0.12 to 1 mm (0.12 mm ≦ T2 ≦ 1 mm) in the present embodiment. . The thickness (T2) of the thermally conductive composite material is preferably set to 0.12 to 0.5 mm.

(Production method)

In the present embodiment, the metal foil layer 3 must also be integrally molded with respect to the fiber-reinforced resin material 2 (2a, 2b). In other words, for example, as shown in Fig. 4 (b), the reinforcing fiber sheets 10Sa and 10Sb are impregnated with the resin R, and the reinforcing fiber sheet (prepreg sheet) 10PG (10PGa, 10PGb) in a so-called prepreg state which has not been completely cured. The two sides of the metal foil layer 3 are pressed and integrally laminated, and if necessary, the resin R is cured by heating.

As described in the first embodiment, the impregnated resin of the prepreg sheet 10PG (10PGa, 10PGb) on both sides of the metal foil layer 3 is completely cured, that is, the fiber-reinforced resin material 2 (2a, 2b). In the case of being integrated, there is a fear that the heat dissipation or rigidity of the adhesive layer is lowered depending on the thickness of the adhesive.

(reinforcing method)

The thermally conductive composite material 1 produced as described above is integrally joined to the to-be-reinforced body 101 in the same manner as in the first embodiment.

As described above, the reinforcing body 101 of the fiber-reinforced plastic product thus obtained has a high rigidity and heat dissipation property (thickness (T2) of 0.12 to 1 mm and a tensile modulus of elasticity of 80 GPa or more). That is, the thermally conductive composite material 1) is reinforced, whereby the deformation caused by the external force can be effectively prevented from being prevented from being damaged inside the device, and the device is not formed in the device. The hot spots caused by the internal exothermic source can be diffused.

(Explanation of experimental examples)

Then, in order to confirm the effect of the thermally conductive composite material 1 of the present invention, a test sample was prepared, and the mechanical strength and heat dissipation were tested for performance. This experimental example is shown as Experimental Example 10 in the above Tables 4 and 5. The materials, constitution, and dimensions of the test samples used in Experimental Example 10 are shown in Table 4, and the test results are shown in Table 5.

Experimental Example 10

(test sample)

In Experimental Example 10, according to the constitution of the present invention, a fiber-reinforced composite material (metal foil core-asphalt-based CFRP unidirectional 0°/90° plate) produced by the following method was used: the pitch-based carbon fiber was pulled in one direction The prepreg impregnated with the resin in the unidirectional carbon fiber sheet is laminated on both sides of the copper foil 3 in the X direction and the Y direction and integrated.

Further, the pitch-based carbon fibers and copper used in Experimental Example 10 were the same as those in Experimental Examples 1 to 9. The total fiber basis weight used was set as shown in Table 4.

The test sample used in Experimental Example 10 was set to have a length × width of 100 mm × 50 mm in the same manner as Experimental Examples 1 to 9, and the thickness of each sample (total thickness T2, metal foil layer thickness t3, fiber reinforced resin material thickness t2) As shown in Table 4.

(heat dissipation)

The heat dissipation of the test samples was measured by the same method as Experimental Examples 1 to 9.

The measurement results of heat dissipation are shown in Table 5. The temperature immediately below the heater of the sample of Experimental Example 10 was 39.4 ° C, and the sign of heat diffusion was slightly worse than that of the sample of Experimental Example 7 above. (◎~○: Good heat dissipation).

(tensile elastic modulus, tensile rigidity)

The tensile elastic modulus (E), tensile rigidity, and weight were determined by calculation in the same manner as in Experimental Examples 1 to 9. The results of tensile modulus, tensile rigidity and weight are shown in Table 5. According to Table 5, the test sample of Experimental Example 10 constructed according to the present embodiment was excellent in heat dissipation and rigidity, and was also lightweight in the above-mentioned Experimental Example 5 having a large thickness in terms of weight.

1‧‧‧ Thermally conductive composites

2‧‧‧Fiber reinforced resin materials

2a‧‧‧Fiber reinforced resin materials

2b‧‧‧Fiber reinforced resin material

3‧‧‧metal foil layer

3a‧‧‧metal foil layer

3b‧‧‧metal foil layer

101‧‧‧Reinforced body

101a‧‧‧Bottom section

T1‧‧‧ thickness

T2‧‧‧ thickness

T2‧‧‧ thickness

T2a‧‧‧ thickness

T2b‧‧‧ thickness

T3‧‧‧ thickness

T3a‧‧‧ thickness

T3b‧‧‧ thickness

Claims (10)

A thermally conductive composite material comprising a sheet-like fiber-reinforced resin material containing continuous reinforcing fibers and a metal foil layer integrally bonded to both sides of the fiber-reinforced resin material, and having a thickness of 0.07 to 1 mm, characterized in that the fiber The thickness of the reinforced resin material is set to 0.05 mm or more, less than 1 mm, the thickness of the metal foil layer is set to 0.009 to 0.1 mm, and the tensile elastic modulus of the thermally conductive composite material is 80 GPa or more. A thermally conductive composite material comprising a metal foil layer and a sheet-like fiber-reinforced resin material comprising continuous reinforcing fibers integrally bonded to both sides of the metal foil layer, the thickness being set to 0.12 to 1 mm, characterized in that the fiber reinforcement The thickness of the resin material is set to 0.05 mm or more, less than 1 mm, the thickness of the metal foil layer is set to 0.009 to 0.1 mm, and the tensile elastic modulus of the thermally conductive composite material is 80 GPa or more. The thermally conductive composite material according to claim 1 or 2, wherein the fiber-reinforced resin material contains 20% or more of pitch-based carbon fiber having a reinforcing fiber of 100 W/mK or more in terms of fiber volume content. The thermal conductivity and the tensile modulus of elasticity above 400 GPa. The thermally conductive composite material according to claim 1 or 2, wherein the fiber-reinforced resin material is a reinforced fiber-based pitch-based carbon fiber, a PAN (polyacrylonitrile)-based carbon fiber or a glass fiber, or a mixture of the fiber. The above is the result. The thermally conductive composite material according to any one of claims 1 to 4, wherein the fiber-reinforced resin material is formed by continuously drawing the reinforcing fibers in one direction and impregnating the resin. Formed, and/or impregnated with a resin woven in at least two axial directions. The thermally conductive composite material according to any one of claims 1 to 4, wherein the fiber-reinforced resin material is a sheet formed by continuously stretching the reinforcing fibers in one direction and impregnating the resin, at least 2 The layer is formed in the axial direction. The thermally conductive composite material according to any one of claims 1 to 6, wherein the metal foil layer is made of a metal having a thermal conductivity of 50 W/mK or more. The thermally conductive composite material according to any one of claims 1 to 7, wherein the thermally conductive composite material has a thickness of 0.12 to 0.5 mm. A method for producing a thermally conductive composite material in which a metal foil layer is integrated on both sides of a fiber-reinforced resin material, the thermally conductive composite material having a sheet-like fiber-reinforced resin material containing continuous reinforcing fibers and integrally bonded to the fiber-reinforced resin material The metal foil layer on both sides, the thickness of the thermally conductive composite material is set to 0.07 to 1 mm, and the tensile elastic modulus is 80 GPa or more, characterized in that: (a) the continuous reinforcing fibers are prepared to be aligned at least in one direction. And the impregnated resin is semi-hardened, the fiber basis weight is set to 25 to 600 g/m ² , and the fiber volume fraction is set to 20 to 70% of at least one prepreg sheet, and the thickness is set to 0.009 to 0.1 mm. (b) The metal foil is pressed onto both surfaces of the prepreg sheet to be integrally laminated, and (c) thereafter, the prepreg sheet is cured to obtain a fiber-reinforced resin material. A method for producing a thermally conductive composite material in which a fiber-reinforced resin material is integrated on both sides of a metal foil layer, the thermally conductive composite material having a metal foil layer and a sheet containing continuous reinforcing fibers integrally bonded to both sides of the metal foil layer Fibrous reinforced resin material, the thermal conductivity The thickness of the composite material is set to 0.12 to 1 mm, and the tensile elastic modulus is 80 GPa or more, and is characterized in that: (a) a fiber unit area in which continuous reinforcing fibers are aligned at least in one direction and impregnated with a resin to perform semi-hardening The weight is set to 25 to 600 g/m2, at least one prepreg sheet having a fiber volume content of 20 to 70%, and a metal foil having a thickness of 0.009 to 0.1 mm, and (b) the prepreg The body sheet is pressed to both sides of the metal foil to be integrally laminated, and (c) thereafter, the prepreg sheet is cured to obtain a fiber-reinforced resin material.