TW201920592A - 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

   Thermally conductive composite material and manufacturing method thereof   

The present invention relates to a case, a case box, or a mobile digital medical cassette as an information terminal device represented by a smart phone, an input board, a portable computer, or the like, or other electrical machine cases that require thermal measures. A thermally conductive composite material with high rigidity (high elasticity) and high heat dissipation characteristics, such as thermal conductivity, which is used for a reinforcing plate such as a body, and a manufacturing method thereof.

At present, for example, in information terminal devices such as smart phones, input boards, and portable computers, a case, a case, a battery, a circuit board, and the like, a case surface material, a top plate, etc. integrally mounted on the case, etc. In order to reduce weight, a method of forming and manufacturing a plastic-based material has become mainstream. For example, as shown in FIG. 1, a smart phone 100 having a schematic configuration generally includes a thin box-shaped case (or case box) 101 on which a battery, a circuit board, and the like are mounted, and the case (or case box) 101 is mounted on the case. It has a cover body 102 including a display and a touch panel.

In recent years, in the above-mentioned information terminal devices, as the processing performance of the CPU and the like has increased, the increase in the battery size and the increase in heat generation caused by the increase in power consumption of semiconductor devices and the like have been unavoidable. The rigidity of the body (or case box) and heat dissipation (thermal conductivity).

Conventionally, graphite sheets and the like generally used as heat-radiating members have amazing thermal conductivity, but they are extremely expensive and have problems in terms of rigidity.

Therefore, Patent Document 1 proposes a heat sink composed of a carbon fiber composite material for cooling a heating element such as a semiconductor used in an integrated circuit. The thermal conductivity of the carbon fiber composite material of the heat sink is anisotropic, so it is formed by joining a highly thermally conductive metal around the carbon fiber composite body equipped with heating elements such as semiconductors. The carbon fiber of the carbon fiber composite body is perpendicular to the surface on which the heating element is mounted. Ground uniaxial alignment.

In addition, Patent Document 2 proposes a thermally conductive composite molded product in which an aluminum flat plate is adhered to a bottom surface portion of a carbon fiber reinforced plastic molded product using an adhesive as a housing of a computer having a high-performance CPU. The carbon fiber reinforced plastic molded product has a box shape. Long fiber particles.

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

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

It is also understood from the description of the above-mentioned patent documents that carbon fibers, which are reinforcing fibers used in carbon fiber reinforced composite materials, transmit heat well in the direction of the fiber axis, but hardly transmit heat in a direction perpendicular to the fiber axis. Therefore, the carbon fibers near the surface of the carbon fiber-reinforced composite material contribute to heat diffusion to some extent, but the thermal conductivity is poor relative to the thickness direction of the carbon fiber-reinforced composite material, so the carbon fibers far away from the surface hardly diffuse the heat. Helpful. That is, for example, the pitch-based carbon fiber has a very high thermal conductivity of 100 to 600 W / mK, but it has the following problems: it exhibits anisotropy only by exerting its ability in the direction of the fiber axis, and it is difficult to make it. In the case of a carbon fiber-reinforced composite material prepared by impregnating a carbon fiber with a resin, the poor thermal conductivity of the resin affects the desired thermal conductivity characteristics and the like.

In addition, the hybrid heat sink using a carbon fiber composite material described in the above-mentioned Patent Document 1 is configured, for example, as follows: a carbon fiber composite body having a thickness of 2 mm is embedded in a central portion of a copper sheet having a thickness of 30 mm square and 2 mm thick, and the carbon fiber composite body Equipped with heating elements. The carbon fiber-reinforced plastic molded product described in Patent Document 2 has, for example, a thickness of the carbon fiber-reinforced plastic molded product of 1.4 mm, a weight average fiber length of long fiber particles of 0.38 mm, and a thickness of an aluminum flat plate of 0.6 mm.

The mixed heat sink or the carbon fiber reinforced plastic molded product described in Patent Documents 1 and 2 cannot be used as a case cover of a smartphone or the like or a reinforcing plate for reinforcing the case.

Therefore, the present inventors carried out a large number of research experiments in order to improve the above-mentioned problems of the heat sink or the carbon fiber reinforced plastic molded product using the conventional carbon fiber composite material, and found that the contact portion with the heat radiation body will be The surface is made of metal, and a fiber-reinforced composite material, such as a carbon fiber reinforced composite material, is arranged on the inside. The thickness and the thickness of the fiber-reinforced composite material are optimally designed so that the thermal conductivity of the metal, which is an isotropic material, can be used to promote heat diffusion in an in-plane direction other than the fiber axis direction of the fiber-reinforced composite material in the in-plane direction and thickness. Good heat dissipation (thermal conductivity) is maintained in all directions, and high rigidity is ensured.

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

The above object is achieved by using the thermally conductive composite material of the present invention. In short, according to a first aspect of the present invention, there is provided a thermally conductive composite material having a sheet-like fiber-reinforced resin material containing continuous reinforcing fibers and metal foil layers integrally bonded to both sides of the fiber-reinforced resin material The thickness is set to 0.07 to 1 mm, which is characterized in that the thickness of the fiber-reinforced resin material is set to 0.05 mm or more and less than 1 mm, the thickness of the metal foil layer is set to 0.009 to 0.1 mm, and the thermally conductive composite material is The tensile elastic modulus is 80 GPa or more. According to a second aspect of the present invention, there is provided a thermally conductive composite material having a metal foil layer and a sheet-shaped fiber-reinforced resin material containing continuous reinforcing fibers integrally bonded to both sides of the metal foil layer, and the thickness is set to 0.12 Those with a thickness of ~ 1 mm are characterized in that the thickness of the fiber-reinforced resin material is set to 0.05 mm or more and less than 1 mm, the thickness of the metal foil layer is set to 0.009 to 0.1 mm, and the elastic modulus of the thermally conductive composite material is stretched. The number is 80 GPa or more.

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

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

According to another aspect of the first and second aspects of the present invention, the fiber-reinforced resin material is formed by drawing continuous impregnated fibers in one direction and impregnating the resin, and / or is woven in at least two directions. The resulting fabric is impregnated with resin.

According to another aspect of the first and second aspects of the present invention, the fiber-reinforced resin material is a sheet formed by continuously aligning the reinforcing fibers in one direction and impregnated with the resin, and is laminated in at least two axes. Production.

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

According to another aspect of the present invention, the thickness of the thermally conductive composite material is 0.12 to 0.5 mm.

According to a third aspect of the present invention, a method for manufacturing a thermally conductive composite material with a metal foil layer integrated on both sides of a fiber-reinforced resin material is provided. The thermally conductive composite material has a sheet-shaped fiber-reinforced resin containing continuous reinforcing fibers. Material and metal foil layers integrally bonded to both sides of the fiber-reinforced resin material, the thickness of the thermally conductive composite material is set to 0.07 to 1 mm, and the tensile modulus of elasticity is 80 GPa or more, which is characterized by: (a) ready to be continuous At least one prepreg sheet with the unit weight of the reinforcing fibers aligned in at least one direction and impregnated with resin for semi-hardening is set to 25 to 600 g / m ² and the fiber volume content rate 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 onto both sides of the prepreg sheet and laminating it integrally, (c) thereafter, hardening the prepreg sheet Fiber-reinforced resin material.

According to a fourth aspect of the present invention, a method for manufacturing a thermally conductive composite material in which a fiber-reinforced resin material is integrated on both sides of a metal foil layer is provided. The thermally conductive composite material has a metal foil layer and is integrally bonded to the metal foil layer. A sheet-shaped fiber-reinforced resin material containing continuous reinforcing fibers on both sides of the sheet. The thickness of the thermally conductive composite material is set to 0.12 to 1 mm and the tensile modulus of elasticity is 80 GPa or more. It is characterized by: (a) preparing continuous The weight per unit area of the fibers where the reinforcing fibers are aligned in at least one direction and impregnated with resin for semi-hardening is set to 25 to 600 g / m ² , and the fiber volume content rate is set to at least one prepreg sheet of 20 to 70%, And a metal foil having a thickness of 0.009 to 0.1 mm, (b) the prepreg sheet is pressed against both sides of the metal foil to be laminated integrally, and (c) the prepreg sheet is then hardened to form Fiber-reinforced resin material.

According to the present invention, it has high rigidity and heat dissipation, and can be prevented from being damaged due to deformation caused by external force of the reinforced body only by being attached to the reinforced body, and can be spread without forming hot spots.

1‧‧‧ thermally conductive composite material

2‧‧‧ fiber reinforced resin material

3‧‧‧ metal foil layer

10‧‧‧ fiber reinforced sheet

10PG‧‧‧Prepreg

101‧‧‧ Reinforced

FIG. 1 is a perspective view showing a schematic configuration of a smart phone, and shows a state in which a case or a case of a smart phone is reinforced by using the thermally conductive composite material of the present invention.

FIG. 2 (a) is a schematic cross-sectional view of a casing or a case of a smart phone made of a reinforced body reinforced with a thermally conductive composite material of the present invention, and FIG. 2 (b) is a thermally conductive composite of the present invention An enlarged cross-sectional view of a schematic configuration of an example of a material. FIG. 2 (c) is an enlarged 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 example of a prepreg sheet (fiber-reinforced resin material) and a reinforced fiber sheet before the metal foil layer is bonded, and FIG. 3 (b) is a view showing a laminated state of the prepreg sheet Figure of an example.

4 (a) and 4 (b) are schematic configuration diagrams illustrating a method for producing a thermally conductive composite material according to the present invention.

Fig. 5 (a) and Fig. 5 (b) are a top view and a sectional view, respectively, for explaining the size and shape of a test sample of a thermally conductive composite material, and Fig. 5 (c) is a temperature measurement method for testing the heat dissipation of the test sample. Illustration.

Hereinafter, the thermally conductive composite material of the present invention will be described in detail with reference to the drawings.

Example 1

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

FIG. 2 (a) is a cross-sectional view showing a schematic configuration of a casing or a casing 101 of a smart phone made of a reinforced body reinforced with the thermally conductive composite material 1 of the present invention, and FIG. 2 (b) is the present invention. An enlarged sectional view showing a schematic configuration of an embodiment of the thermally conductive composite material 1. In addition, unlike FIG. 1, the bottom plate portion 101 a of the reinforced body 101 in FIG. 2 (a) is located above and illustrated. 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 Example 2.

First, referring to FIG. 2 (b), in this embodiment, the thermally conductive composite material 1 of the present invention includes a sheet-shaped fiber-reinforced resin material 2 containing continuous reinforcing fibers and a fiber-reinforced resin material 2 integrally bonded to the fiber-reinforced resin material 2. Metal foil layers 3 (3a, 3b) on both sides. According to the present invention, if also referring to FIG. 3, the thermal diffusion of the thermally conductive composite material 1 basically realizes the reinforcing fiber f of the fiber-reinforced resin material 2 by the fiber-reinforced resin material 2 and the metal foil layer 3. The thermal diffusion in the direction of the fiber axis (direction XX in FIG. 3), and the direction crossing (orthogonal) to the direction of the fiber axis of the reinforcing fiber f (direction YY in FIG. 3) are performed by the metal foil layer 3.

The heat dissipation required for the thermally conductive composite material 1 is achieved by designing the thickness of the thermally conductive composite material 1 and each of the constituent members 2 and 3. That is, in the present invention, the thermal conductivity in the thickness direction of the thermally conductive composite material 1 (ZZ direction in FIG. 3) is achieved by a structure orthogonal to the direction of the reinforcing fibers f of the fiber-reinforced resin material 2 (FIG. (3 in the YY direction). The optimum fiber-reinforced resin material 2 and the metal foil layer 3 have a poor thermal conductivity.

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). If the thickness (T1) exceeds 1 mm, as in this embodiment, when the thermally conductive composite material 1 is used as a reinforcing plate such as a casing (or casing) 101 of a smart phone, The space inside the reinforced body 101 will be excessively occupied. In order to accommodate the main components of the smart phone, the housing of the smart phone as the reinforced body 101 will inevitably increase, and the total weight will also increase, which will damage the miniaturization, Lightweight. In addition, if the thickness (T1) is less than 0.07 mm, it will be difficult to achieve the high rigidity of the reinforcing plate as the object of the invention, and the fiber-reinforced resin material 2 and the metal foil layer 3 will become 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.

From the results of experimental research by the inventors, it can be seen that the thermally conductive composite material 1 needs to have a tensile modulus of elasticity in order to obtain the required tensile rigidity (tensile modulus of elasticity × cross-sectional area). At least 80 GPa greater than the tensile elastic modulus (70 GPa) of aluminum. If the tensile elastic modulus 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 more detail.

(Fiber-reinforced resin material)

The thickness (t2) of the sheet-shaped fiber-reinforced resin material 2 is set to be 0.05 mm or more and less than 1 mm (0.05 mm ≦ t2 <1 mm). If the thickness (t2) is 1 mm or more, there is a problem that the heat dissipation property is deteriorated. (t2) If it is less than 0.05 mm, it is difficult to achieve high rigidity as a reinforcing plate, and the fiber-reinforced resin material 2 becomes extremely thin and cannot be manufactured using existing raw materials, leading to problems such as increased costs. 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 of a fiber-reinforced composite material containing 20% or more of pitch-based carbon fibers in terms of fiber volume fraction (Vf). The pitch-based carbon fibers have a thermal conductivity of 100 W / mK or more and a tensile elastic modulus. It is set to 400 GPa 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%. That is, according to this embodiment, when pitch-based carbon fibers are used, the tensile elastic modulus of the fiber-reinforced resin material 2 having a fiber volume content rate of 20% is set to 400 GPa × fiber volume content rate (Vf) 20% = 80 GPa. That is, the present situation is that when 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 this structure, a thermally conductive composite material 1 having a tensile elastic modulus of 80 GPa or more according to the present invention can be obtained.

The fiber-reinforced resin material 2 is produced by impregnating a resin R with continuous reinforcing fibers f. As the reinforcing fibers f, carbon fibers can be used optimally. As described above, pitch-based carbon fibers are preferred. According to the specifications of the required reinforcing plate, that is, the thermally conductive composite material 1, PAN-based carbon fibers that are inferior to pitch-based carbon fibers in terms of tensile elastic modulus and thermal conductivity can also be used. In addition, depending on the case, in addition to carbon fibers, glass fibers that are inferior to carbon fibers in terms of tensile elastic modulus and thermal conductivity can also be used. Of course, these fibers may be mixed and used.

Table 1 shows the tensile elastic modulus and thermal conductivity of the reinforcing fibers that can be used in the present invention.

Moreover, as shown in FIG. 3 (a), the fiber-reinforced resin material 2 that can be used in the present invention is prepared by using a prepreg sheet 10PG prepared by impregnating a resin R with a resin continuous in a fiber axis direction. The above-mentioned reinforcing fibers f are aligned in one direction to form a sheet-like reinforcing fiber sheet 10S, and are semi-hardened (B-staged).

It is preferable to use a prepreg sheet having a fiber basis weight of 25 to 600 g / m ² , and the fiber volume fraction (Vf) of the carbon fiber is set to 20% or more as described above. If necessary, a plurality of prepreg sheets 10PG are laminated and used. 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, and preferably 0.1 to 0.46 mm is formed as described above.

In the above description, the UD shape produced by pulling the reinforcing fibers f in one direction has been described, and a plurality of prepreg sheets 10PG may be laminated and used so that the reinforcing fibers f cross each other as necessary. That is, the prepreg sheet 10PG of the UD shape can be produced by laminating the reinforcing fiber f in one direction along at least 2 axes in the direction of the reinforcing fiber f and 3 axes and 4 axes depending on the situation. . For example, as shown in FIG. 3 (b), three prepreg sheets 10PG (0 °) in which the reinforcing fiber f is oriented in the direction of 0 °, and 10 prepreg sheets 10PG in which the reinforcing fiber f is oriented in the direction of 90 ° (90 °) and reinforcing fiber f were laminated with 10PG (0 °) of prepreg sheets aligned in the direction of 0 °. Furthermore, although not shown, a prepreg sheet 10PG (+ 45 °) oriented in the direction of + 45 ° using reinforcing fiber f and a prepreg sheet oriented in the direction of -45 ° using reinforcing fiber f may be used. 10PG (-45 °) replaces the 3-axis structure of 10PG (90 °) of the prepreg sheet oriented in the 90 ° direction instead of the above-mentioned reinforcing fiber f, or it may be set as a pre-aligned orientation using the above-mentioned reinforcing fiber f in the 90 ° direction. In addition to the immersion sheet 10PG (90 °), the prepreg sheet 10PG (+ 45 °) oriented in the + 45 ° direction with the reinforcing fiber f and the prepreg sheet 10PG oriented in the -45 ° direction with the reinforcing fiber f (-45 °) 4-axis configuration.

Further, the reinforcing fiber sheet 10S may be made into a fabric (cloth) such as a plain weave, a twill weave, or a satin weave formed by weaving one or more kinds of reinforcing fibers f as necessary. Furthermore, you may use the said UD shape together with cloth.

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

The reinforcing fibers f in the fiber-reinforced resin material 2 are as described above. For example, when pitch-based carbon fibers are used, it is important to include 20% or more in terms of the fiber volume fraction (Vf). Usually set to 20 ~ 70%. If 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 Mechanical properties and other issues. The fiber volume fraction (Vf) is preferably set in a range of 40 to 65%.

(Metal foil layer)

The metal foil layer 3 (3a, 3b) is made of a metal such as aluminum or copper having a thermal conductivity of 200 W / mK or more. Depending on the required degree of heat dissipation, it is also possible to use, for example, iron or nickel or brass with a thermal conductivity of 50 to 200 W / mK inferior to these metal materials. Furthermore, it can also be made from an alloy of the above-mentioned metals such as aluminum alloys having 50 to 200 W / mK. The metal foil layers 3a and 3b may be the same metal or different metals depending on the shape of the thermally conductive composite material 1.

In addition, the thicknesses (t3a, t3b) of the metal foil layers 3 (3a, 3b) are set to 0.009 to 0.1mm (0.009mm ≦ t3a, t3b ≦ 0.1mm), respectively. If the thickness (t3a, t3b) exceeds 0.1mm, 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 is not generated, which is disadvantageous in terms of rigidity. In addition, since the density of the metal foil layer 3 is generally higher than that of the fiber-reinforced resin material 2, as the thickness (t3a, t3b) increases, the weight of the thermally conductive composite material 1 increases. If the thickness (t3a, t3b) is less than 0.009 mm, a problem arises that the existing raw materials cannot be used and the cost increases. Furthermore, since the material is too thin, it may be bent or broken, which makes handling extremely difficult. Preferably, the thicknesses (t3a, t3b) of the metal foil layers 3 (3a, 3b) are 0.01 to 0.05 mm. Furthermore, depending on the shape of the thermally conductive composite material 1, the thicknesses (t3a, t3b) of the metal foil layers 3a, 3b may be the same or different.

(Production method)

According to the present invention, the metal foil layer 3 (3a, 3b) must be integrally formed with the fiber-reinforced resin material 2. That is, as shown in FIG. 4 (a), for example, the metal foil layer 3 (3a, 3b) is pressed onto both sides of a so-called prepreg sheet 10PG impregnated with the resin R impregnated with the reinforcing fiber sheet 10S, and a volume layer is formed. Heating is required to harden the resin R.

If the metal foil layer 3 (3a, 3b) is adhered to the prepreg sheet 10PG using the adhesive, the resin R is completely hardened, that is, the fiber-reinforced resin material 2 is integrated into one body. Depending on the thickness of the adhesive, the heat dissipation property or rigidity of the adhesive layer is reduced. In addition, it is difficult to perform pre-substrate treatment before the metal foil layer 3 or to ensure uniformity of the amount of adhesive applied, or the pre-substrate treatment itself is complicated. In addition, a step of attaching is generated, and the cost increases accordingly.

(Reinforcement method)

The thermally conductive composite material 1 produced as described above is, for example, integrally bonded to a smartphone case or a case box (reinforced body) 101 (see FIG. 1).

A jig or the like is prepared for easy operation. For example, it is integrally bonded to a top plate that becomes a top surface of a pre-molded case box or casing with an adhesive or a double-sided tape as appropriate. In this case, by appropriately setting the thickness and material of the adhesive, there is no reduction in heat dissipation or rigidity. In addition, it can also be integrally joined to the reinforced body 101 because it is set in a molding die during the molding of the smartphone case or the case box 101 and press-molded at the same time.

As the reinforced body 101 of the fiber-reinforced plastic product obtained as described above, the reinforced body having high rigidity and heat dissipation is set as described above with a thickness (T1) of 0.07 to 1 mm and a tensile elastic modulus of 80 GPa or more. (That is, the thermally conductive composite material 1), thereby effectively preventing deformation due to external forces and preventing damage to the inside of the device, and it can spread without forming a hot spot caused by a heat radiation source housed inside the device.

(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 made, and performance tests were performed on mechanical strength and heat dissipation. Tables 2 and 4 show the materials, structures, dimensions, etc. of the test samples used in this experimental example, and Tables 3 and 5 show the test results.

(1) Experimental examples 1 to 4

(Test sample)

In Experimental Example 1, a thin plate-shaped aluminum (A5052) simple substance (metal simple substance) was used. In Experimental Example 2, a carbon fiber-reinforced resin (CFRP cloth) impregnated with a resin was used in a cloth (fabric) of pitch-based carbon fiber. In Experimental Example 3, a glass fiber reinforced resin (GFRP cloth) impregnated with a resin in a glass fiber cloth (fabric) and a resin impregnated in a unidirectional carbon fiber sheet in which pitch-based carbon fibers are aligned in one direction are used. Carbon fiber reinforced resin (CFRP unidirectional) laminated glass-carbon fiber bonded composite material (GFRP cloth-CFRP unidirectional). In Experimental Example 4, according to the structure of the present invention, a fiber-reinforced composite material (metal foil surface layer-CFRP unidirectional core) produced by the following method was used: copper foil was integrally molded to align the pitch-based carbon fibers in one direction The unidirectional carbon fiber sheet is impregnated with both sides of a carbon fiber reinforced resin (CFRP unidirectional) resin.

In addition, the pitch-based carbon fibers used in Experimental Examples 2, 3, and 4 used fiber bundles having an average diameter of a single filament of 9 μm, a number of bundles of 3000, 6000, or 12,000, that is, pitch-based carbon fiber stocks (Japan Graphite Fiber Co., Ltd. Co., Ltd. (trade name: GRANAC XN-80), and impregnated epoxy resin with fibers to obtain a prepreg.

The glass fiber cloth prepreg system used in Experimental Example 3 was manufactured by Mitsubishi Rayon Corporation (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 harden the resin to prepare a test sample. Further, in Experimental Example 4, copper foil was pressed onto both surfaces of the unidirectional carbon fiber sheet prepreg to be laminated, and the resin was cured by heating to produce a 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 elastic modulus: 70GPa Thermal conductivity: 138W / mK

Copper: Tensile elastic modulus: 110 ~ 130GPa Thermal conductivity: 398W / mK

Glass fiber: tensile elastic modulus: 70GPa thermal conductivity: 0.5W / mK

Asphalt-based carbon fiber: Tensile elastic modulus: 780GPa Thermal conductivity: 320W / mK

As shown in Figures 5 (a) and (b), the test sample S used in Experimental Examples 1 to 4 was set to a length × width of 100 mm × 50 mm. The thickness of each sample S (total thickness T1, metal foil layer thickness) t3, the thickness t2 of the fiber-reinforced resin material is shown in Table 2.

(Heat dissipation)

The heat radiation properties of each test sample S were measured as follows.

As shown in FIG. 5 (c), a heater (H) is provided at the center in the width direction of the test sample, that is, the one end in the long-side direction of the test piece S (the left end in FIG. 5 (c)), and the temperature is sensed. The device (TS) measures the temperature of at least the heater installation position of the test piece and the temperature measurement point opposite to the side on which the heater (H) is provided (the right end in FIG. 5 (c)). Measure the temperature at the beginning of the temperature test and when it reaches equilibrium. Judgment of heat dissipation based on the results of temperature measurement is as follows. That is, if the temperature at the point immediately below the heater is high, it is determined that the temperature is not dispersed to the surroundings, and therefore, the heat dissipation is poor. In addition, when the temperature at the measurement point on the other end (the right end in Fig. 5 (c)) of the test piece far from the heater rises, it is determined that the heat is dispersed far away, so the heat dissipation is good.

The measurement results of heat dissipation are shown in Table 3. The temperature directly under the heater of the sample of Experimental Example 1 was the lowest among Experimental Examples 1 to 4, and it was seen that heat spread to the whole ((: Very good heat dissipation). The sample of Experimental Example 2 is the third among Experimental Examples 1 to 4. Although the heat spreads to the entire body like the sample of Experimental Example 1, it is inferior to the sample of Experimental Example 1 (△). The temperature directly under the heater of the sample of Experimental Example 3 was the highest among Experimental Examples 1 to 4, and the heat was stored and the heat was diffused only in one direction (×: Poor heat dissipation). The temperature directly 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 spread to the whole and heat spread 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 obtained by calculation. The tensile rigidity is the product of the tensile elastic modulus (E) of the sample and the cross-sectional area (A) of the sample (in this embodiment, A = 50mm × T1).

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

(2) Experimental examples 5 to 9

In order to further confirm the function and effect of the thermally conductive composite material 1 of the present invention, in addition to the experimental examples 1 to 4 described previously, the thickness (T1) of the thermally conductive composite material 1 was changed, and the thickness test was performed as uniformly as possible. As described above, Table 4 shows the materials, composition, dimensions, etc. of the test samples used in this experimental example, and Table 5 shows the test results.

(Test sample)

In Experimental Example 5, a thin plate-shaped aluminum A5052 simple substance (metal simple substance) was used. The thickness is set to 0.48 mm. In Experimental Example 6, a carbon fiber-reinforced resin (CFRP unidirectional) obtained by laminating a prepreg impregnated with resin in a unidirectional carbon fiber sheet in which pitch-based carbon fibers are aligned in one direction was used. 0 ° / 90 ° plate). In Experimental Example 7, according to the structure of the present invention, a fiber-reinforced composite material (metal foil surface layer—asphalt-based CFRP unidirectional 0 ° / 90 °) produced by integrally molding copper foil on both sides of a carbon fiber reinforced resin was used. The carbon fiber-reinforced resin is obtained by laminating pitch-based carbon fibers in one direction with a unidirectional carbon fiber sheet impregnated with resin in the X direction and the Y direction. In Experimental Example 8, a carbon fiber reinforced resin (PAN-based CFRP unidirectional 0 ° / 90 ° plate) was used. The carbon fiber-reinforced resin was impregnated with resin in a unidirectional carbon fiber sheet in which PAN-based carbon fibers were aligned in one direction. The prepreg is obtained by laminating 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) produced by integrally molding copper foil on both sides of a carbon fiber reinforced resin was used. The carbon fiber-reinforced resin is obtained by laminating prepregs impregnated with resin in a unidirectional carbon fiber sheet in which PAN-based carbon fibers are aligned in one direction in the X and Y directions.

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

The test samples used in Experimental Examples 5 to 9 were the same as in Examples 1 to 4. The length × width was set to 100 mm × 50 mm. The thickness of each sample (total thickness T1, metal foil layer thickness t3, and fiber-reinforced resin material thickness). t2) As shown in Table 4.

(Heat dissipation)

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

The measurement results of heat dissipation are shown in Table 5. The temperature directly under the heater of the sample of Experimental Example 5 was 38.8 ° C, which was the lowest among Experimental Examples 5-9. It can be seen that the heat has spread to the whole (◎: Heat dissipation very good). The temperature of the sample directly under the heater of Experimental Example 6 is 40 ° C and is the same as that of Aluminum of Experimental Example 5. Although the signs of heat diffusion are diffused to the whole, it is inferior to that of Aluminum of Experimental Example 5 (○: heat dissipation is slightly it is good). The temperature directly under the heater of the sample of Experimental Example 7 was 39.8 ° C, and the signs of heat diffusion due to the effect of the copper foil were the same as that of Aluminum of Experimental Example 5 (：: Very good heat dissipation). The temperature directly below the heater of the sample of Experimental Example 8 was 93.4 ° C, and significant heat was accumulated, and the heat was hardly diffused (×: poor heat dissipation). In the sample of Experimental Example 9, the heat storage temperature is about 50 ° C under the heater, but compared with the sample of Experimental Example 8, the heat storage is suppressed by the effect of the copper foil, and the heat is slightly diffused. △: The heat dissipation is slightly inferior).

(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 4. Table 5 shows the results of the tensile elastic modulus, tensile rigidity, and weight. According to Table 5, the test sample of Experimental Example 7 constituted according to the present invention is excellent in terms of heat dissipation and rigidity, and is also light in weight in terms of the aluminum element of Experimental Example 5 which is larger in weight and has the same thickness.

Example 2

FIG. 2 (c) shows a second embodiment of the thermally conductive composite material 1 of the present invention. According to this embodiment, the thermally conductive composite material 1 includes a metal foil layer 3 and a sheet-shaped fiber-reinforced resin material 2 (2 a, 2 b) integrally bonded to both surfaces of the metal foil layer 3.

If the thermally conductive composite material 1 of this embodiment is compared with the thermally conductive composite material 1 of Example 1, the fiber-reinforced resin material 2 (2a, 2b) having a high tensile elastic modulus is arranged in The structure of both surfaces of the metal foil layer 3 is more rigid than the heat dissipation.

The thermally conductive composite material 1 of this embodiment is different from the case of Example 1 in that the sheet-shaped fiber-reinforced resin material 2 (2a, 2b) is integrally bonded to both sides of the metal foil layer 3, and the metal foil layer 3 as a constituent member is different. The sheet-like fiber-reinforced resin material 2 (2a, 2b) has the same material configuration as that of Example 1. Therefore, the description of the metal foil layer 3 and the sheet-shaped fiber-reinforced resin material 2 (2a, 2b) is referred to the description of Example 1 and detailed description is omitted.

In this embodiment, the thickness (T2) of the thermally conductive composite material 1 is set to 1 mm or less as in the case of the above-mentioned embodiment 1. Generally, it is set to 0.12 to 1 mm (0.12 mm ≦ T2 ≦ 1 mm) in this embodiment. . The thickness (T2) of the thermally conductive composite material is preferably set to 0.12 to 0.5 mm.

(Production method)

In this embodiment, the metal foil layer 3 must also be formed integrally with the fiber-reinforced resin material 2 (2a, 2b). That is, for example, as shown in FIG. 4 (b), the reinforcing fiber sheet 10Sa, 10Sb is impregnated with the resin R, and the reinforcing fiber sheet (prepreg sheet) 10PG (10PGa, 10PGb) in a so-called prepreg state that has not yet been completely hardened. The resin R is laminated by pressing on both surfaces of the metal foil layer 3 and integrally laminating it, and heating it as necessary.

As described in Example 1, if the resin impregnated with the prepreg sheet 10PG (10PGa, 10PGb) on both sides of the metal foil layer 3 is subsequently cured, that is, the fiber-reinforced resin material 2 (2a, 2b) On the other hand, when integrated, there is a concern that the heat dissipation property or rigidity of the adhesive layer may be reduced depending on the thickness of the adhesive.

(Reinforcement method)

The thermally conductive composite material 1 produced as described above is integrally bonded to the reinforced body 101 in the same manner as in the case of Example 1.

As the reinforced body 101 of the fiber-reinforced plastic product obtained in this way, as described above, the reinforced body having high rigidity and heat dissipation properties (T2) having a thickness (T2) of 0.12 to 1 mm and a tensile elastic modulus of 80 GPa or more ( That is, it is reinforced by the thermally conductive composite material 1), which can effectively prevent deformation due to external forces and prevent internal damage to the device, and can spread without forming a hot spot caused by a heat source stored in the device.

(Explanation of experimental examples)

Next, in order to confirm the effect of the thermally conductive composite material 1 of the present invention, a test sample was made, and performance tests were performed on mechanical strength and heat dissipation. This experimental example is shown as Experimental Example 10 in Tables 4 and 5 above. Table 4 shows the materials, composition, dimensions, etc. of the test samples used in Experimental Example 10, and Table 5 shows the test results.

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 CFRP unidirectional 0 ° / 90 ° plate) produced by the following method was used: the pitch-based carbon fibers were aligned in one direction The unidirectional carbon fiber sheet impregnated with resin is laminated on both sides of the copper foil 3 in the X direction and the Y direction and integrated.

The pitch-based carbon fibers and copper used in Experimental Example 10 have the same physical properties as those of Experimental Examples 1 to 9. The total fiber basis weight used is set as shown in Table 4.

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

(Heat dissipation)

The heat dissipation properties of the test samples were measured by the same method as in Experimental Examples 1-9.

The measurement results of heat dissipation are shown in Table 5. The temperature directly under the heater of the sample of Experimental Example 10 was 39.4 ° C, and the signs of heat diffusion were slightly worse than the samples 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. Table 5 shows the results of the tensile elastic modulus, tensile rigidity, and weight. According to Table 5, the test sample of Experimental Example 10 constituted according to this example is excellent in terms of heat dissipation and rigidity, and is also relatively light in weight in terms of aluminum in the above-mentioned Experimental Example 5 having a large thickness and the same thickness.

Claims (8)

    A thermally conductive composite material having a sheet-shaped fiber-reinforced resin material containing continuous reinforcing fibers and metal foil layers integrally bonded to both sides of the fiber-reinforced resin material. The thickness is set to 0.07 to 1 mm, and the characteristics are: The thickness of the reinforced resin material is set to 0.05 mm or more and 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 having a metal foil layer and a sheet-shaped fiber-reinforced resin material containing continuous reinforcing fibers integrally bonded to both sides of the metal foil layer. The thickness is set to 0.12 to 1 mm, and the characteristics are: The thickness of the resin material is set to 0.05 mm or more and 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.         For example, the thermally conductive composite material of the scope of application for patent No. 1 or 2, wherein the fiber-reinforced resin material contains more than 20% of pitch-based carbon fibers based on the fiber volume content rate, and the pitch-based carbon fibers have a reinforcing fiber of 100 W / mK or more Thermal conductivity and tensile elastic modulus above 400GPa.         For example, the thermally conductive composite material of the scope of application for patent No. 1 or 2, wherein the reinforcing fiber of the fiber-reinforced resin material is pitch-based carbon fiber, PAN (polyacrylonitrile, polyacrylonitrile) -based carbon fiber or glass fiber, or a mixture of these two kinds of fibers All of the above.         For example, the thermally conductive composite material according to any one of claims 1 to 4, wherein the fiber-reinforced resin material is formed by drawing continuous impregnated fibers in one direction and impregnating the resin, and / or at least along The biaxially woven fabric is impregnated with resin.         For example, 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 drawing continuous impregnation of the reinforcing fibers in one direction and impregnating the resin, with a minimum of 2 Lamination is performed in the axial direction.         For example, 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.         For example, the thermal conductive composite material according to any one of claims 1 to 7, wherein the thickness of the thermal conductive composite material is 0.12 to 0.5 mm.