KR101952997B1 - Graphite plate and method for manufacturing thereof - Google Patents

Abstract

[PROBLEMS] To provide a graphite plate having a small contact resistance without using a heat conduction paste and a method of manufacturing the same.
[MEANS FOR SOLVING PROBLEMS] A surface roughness (Ra) of a graphite plate is 10 μm or more and less than 40 μm, and a rate of change of surface irregularities with respect to a distance of 80 mm is 0.01% or more and 0.135% or less A graphite plate is used. The present invention also provides a method for producing a graphite plate in which a polymer film is heat-treated in an inert gas. The heat treatment performed on the polymer film is performed at a temperature of 2400 DEG C or higher and 3200 DEG C or lower in the atmosphere of the inert gas, cm < ² > and not more than 100 kg / cm < ² >.

Description

TECHNICAL FIELD [0001] The present invention relates to a graphite plate and a method of manufacturing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphite plate used as a heat conduction material and a manufacturing method thereof.

As a conventional method of obtaining a graphite plate excellent in thermal conductivity, there is known a polymer graphitization method (see, for example, Patent Documents 1 and 2) in which a polymer film is heat-treated in an inert gas atmosphere such as nitrogen, argon or helium.

As a method of obtaining a graphite material to be used for a gasket, a sliding material, a crucible, a heating element and the like, although the thermal conductivity is lowered, a kneaded material composed of a carbon material powder such as coke and a binder such as tar or pitch is sintered, (See, for example, Patent Document 3) is known as a graphite material.

The conventional graphite plate was smooth with a glossy surface or an opaque glass-like non-glossy surface. Therefore, when heat is to be transmitted to another member, the contact area becomes small, and the contact resistance loss becomes inevitable. Thus, the surface of the graphite plate is coated with, for example, a heat-conducting paste to improve adhesion.

Japanese Patent No. 2057739 Japanese Patent No. 2975098 Japanese Patent No. 5033325

However, in the above method, since the thermal conductivity of the heat conductive paste is lower than that of the graphite, there is a problem that the overall thermal conductivity is poor.

Separately, the use of a heat-conductive paste has also posed problems such as an increase in the number of members used, an increase in the process and manufacturing time, scattering of the paste at the time of repair, deterioration in quality due to the passage of time and environment.

Accordingly, an object of the present invention is to provide a graphite plate having a small contact resistance without using a heat conduction paste and a method of manufacturing the same.

In order to achieve the above object, the surface roughness (Ra) of the graphite plate is 10 탆 or more and less than 40 탆, and the rate of change of the surface irregularities with respect to a distance of 80 mm is 0.01% A graphite plate of 0.135% or less is used. The present invention also provides a method of producing a graphite plate in which a polymer film is heat-treated in an inert gas, wherein the heat treatment performed on the polymer film is performed at a temperature of 2400 DEG C or higher and 3200 DEG C or lower in the atmosphere of the inert gas, cm < ² > to 100 kg / cm < ² > or less.

As described above, according to the graphite plate of the crepe-shaped surface of the embodiment, the contact resistance loss can be reduced without using the heat conduction paste.

1 is a cross-sectional view of a heat-resistant container in which a polymer film is placed.
2 is a cross-sectional view of a heat-resistant container in which a plurality of polymer films are placed in multiple stages.
3 is a view showing the surface photograph of the crepe-shaped graphite plate and the laser shape measurement result.
4 is a view showing a method of measuring the flatness.
5 is a diagram showing an experiment for comparing heat transfer.
6 is a diagram showing the relationship between the flatness and the surface roughness of the example and the comparative example.
Fig. 7 is a diagram showing the relationship between the thermal conductivity and the contact thermal resistance in Examples and Comparative Examples. Fig.

Hereinafter, embodiments will be described with reference to the drawings.

The graphite plate of the embodiment is a graphite crystal having surface roughness (crepe roughness) at a certain level on the surface. In addition, the production method is to graphitize one polymer film or a plurality of polymer films in a superposed state.

(Production method of graphite plate)

A method for producing a graphite plate using a polymer film as a raw material will be described in detail. The polymer film 3 shown below is used in the raw material and held in a heat-resistant container 1 having a heat resistance of 3200 占 폚 or more as shown in Fig. 1, and the container is heated. 1 is a cross-sectional view of a heat-resistant container 1 which is placed in a furnace.

The polymer film (3) as a raw material is placed on the bottom of the heat-resistant container (1). The polymer film (3) is pressed into the block (2) during heating. The heating method may be resistance heating heating, induction heating heating, or the like. The atmosphere is inert gas (argon, helium, nitrogen, etc.). As a result, the polymer film 3 becomes the graphite plate 5.

(Graphite plate 5)

Since the graphite plate 5 of the embodiment is a structure in which the hexagonal mesh-shaped two-dimensional crystals of the graphite are superimposed on the layer, the thermal conductivity in the plane direction differs from that in the thickness direction.

(1) Thermal conductivity in the plane direction

Since the heat is conducted by vibration, if the covalent bonds of the hexagonal mesh structure are destroyed, the heat conductivity is not higher than 700 W / mK. When all the covalent bonds of the hexagonal mesh structure are connected, the thermal conductivity is 1500 W / mK. Therefore, as the graphite plate 5 of the embodiment in which the two-dimensional crystal of the hexagonal mesh shape of the graphite is layered, a graphite plate 5 having a thermal conductivity of 700 W / mK or more and 1500 W / mK or less in the plane direction is used.

(2) Thermal conductivity in the thickness direction

The thickness direction of the graphite crystal is connected by a van der Waals force, and since it is not as strong as a covalent bond, its thermal conductivity is also small. When van der Waals forces are all destroyed, they do not have a thermal conductivity greater than 2 W / mK. When they are all connected, the thermal conductivity is 20 W / mK. Therefore, the graphite plate of the embodiment in which the layered structure is superimposed has a thermal conductivity of 2 W / mK or more and 20 W / mK or less in the thickness direction.

(3) The thermal conductivity of the graphite plate 5 of the embodiment

As a result, the thermal conductivity of the graphite plate 5 of the embodiment in the plane direction is 700 W / mK or more and 1500 W / mK or less, and the thermal conductivity in the thickness direction is 2 W / mK or more and 20 W / m or less.

(4) Density of graphite plate (5)

The density of the graphite plate 5 is determined according to the destruction method of the crystal structure, and the apparent density at the state where the covalent bond and the van der Waals force are connected is 2.2 g / cm ³ . Even when the covalent bond and van der Waals force are destroyed, the density is 1.0 g / cm < ³ > When this layered structure is destroyed, the density becomes smaller than 1.0 g / cm < ³ >. Thus, the density of the graphite crystals in the embodiment of the graphite plate 5 is used is not more than, 1.0g / cm ³ at least 2.2g / cm ^3.

(5) Thickness of the graphite plate 5

The thickness of the graphite plate 5 in the embodiment is 25 占 퐉 or more and 2 mm or less. If the thickness of the graphite plate 5 is less than 25 占 퐉, the pressure can not be uniformly applied to the graphite plate 5, and the surface can not be controlled. As a result, the surface of the graphite plate 5 can not be formed into a crepe shape.

If the thickness of the graphite plate 5 is made thicker than 2 mm, it is difficult to remove the gas at the central portion, and the surface can not be formed into a crepe shape while maintaining high crystallinity as a whole.

The graphite plate 5 of the embodiment has a crepe shape on its surface. As a result, the loss of contact thermal resistance with other members can be reduced. Therefore, it is not necessary to use a heat-conductive paste or the like as a light-shielding material for contact resistance, so that it can be used in a high-temperature industrial instrument field where the heat-conductive paste is deteriorated.

(Polymer film (3) of raw material)

The polymer film to be used as a raw material of the graphite plate 5 is a polymer having a benzene ring and is a polymer having a benzene ring and is preferably a polyimide such as polyimide, polyamide, polyoxadiazole, polybenzothiazole, polybenzobisthiazole, polybenzoxazole, Sol, polyparaphenylenevinylene, polyphenylenebenzimidazole, polyphenylenebenzobisimidazole, polythiazole, and is preferably at least one kind of polymer film selected from these. This is because the thermal conductivity of the finally obtained graphite plate 5 is high.

The thickness of the polymer film used is 2 占 퐉 or more and 150 占 퐉 or less, and preferably 12 占 퐉 or more and 125 占 퐉 or less. If it is thinner than 12 탆, wrinkles tend to be caused by static electricity. If it is thinner than 2 탆, the surface is disturbed by wrinkles. If it is thicker than 125 m, the width of the gas release control condition is small, and control becomes difficult. If it is thicker than 150 μm, the gas can not escape and the surface becomes uneven.

Particularly, the polymer film having a thickness of 25 占 퐉 or more and 75 占 퐉 or less is not easily wrinkled and the release of gas is easy to control, so that a homogeneous graphite plate 5 can be easily produced.

(Heat treatment temperature)

The two-dimensional crystal structure and the layered crystal structure of the hexagonal mesh shape of the graphite are determined according to the heat treatment temperature applied. If the heat treatment temperature is lower than 2400 占 폚, the hexagonal mesh shape of the graphite can not be two-dimensionally crystallized, and a layered structure can not be obtained. No atomic transfer occurs.

When the heat treatment temperature is 2600 DEG C or higher, the structure in which the graphite plates 5 are superimposed in layers is entirely preferable.

If the heat treatment temperature is higher than 3200 占 폚, the graphite plate 5 starts to sublimate, which is not good. As a result, the heat treatment temperature is required to be 2400 DEG C or higher, preferably, 2600 DEG C or higher and 3200 DEG C or lower.

(Pressure)

The two-dimensional (plane direction) crystallization of the graphite plate 5 is a phenomenon occurring at several hundreds of nm, and is mainly determined by the heat treatment temperature as described above.

On the other hand, pressing at the time of heat treatment causes a folding at a level of μm on the surface of the graphite plate 5. In the present embodiment, the contact thermal resistance loss is reduced by controlling the surface property at this μm level. Heat is applied to the polymer film 3 to progress the graphitization, and the surface property of the graphite plate 5 is controlled by pressing. Also, at least a heat treatment of 2400 DEG C or more is required. It is necessary to move the atoms.

In this embodiment, the surface property of the graphite plate 5 is controlled to a certain range to lower the thermal resistance of the surface. The surface properties can be known from the parts of the examples, but are as follows.

The surface roughness is not less than 10 占 퐉, less than 40 占 퐉, and the flatness is not less than 0.01% and not more than 0.135%.

In the case of the conventional graphite plate 5, no pressurization or various pressurizing methods are used. In this embodiment, at a temperature of 2400 DEG C or higher and 3200 DEG C or lower, a pressure of 10 kg / cm < ² > and 100 kg / cm < ² >

If the pressing force is lower than 10 kg / cm ² , the surface roughness becomes larger than 40 μm and the flatness becomes larger than 0.135%.

If the pressing force is higher than 100 kg / cm ² , the surface roughness becomes less than 10 μm and the flatness becomes less than 0.01%.

Among the more than 2400 ℃, the heat treatment temperature below 3200 ℃, 10kg / cm ² or more, 100kg / cm ² by the application of less than the pressure of, the surface roughness is 10μm or more, 40μm or less, the flatness of 0.01% or more and 0.135% or less It is possible to reduce the contact resistance with other members.

If the temperature is lower than 2400 占 폚, the surface of the polymer film 3 can not be controlled even if pressure is applied.

In the course of the heat treatment, oxygen, nitrogen, and hydrogen are released from the polymer film 3, which is a combination of carbon, oxygen, nitrogen, and hydrogen. The graphite plate 5 having high crystallinity can be obtained by recrystallizing only carbon. If the crystallinity is not high, the graphite plate 5 having a thermal conductivity of 700 W / mK or more and 1500 W / mK or less can not be obtained.

The release of oxygen, nitrogen, and hydrogen is carried out in the form of a gas, so that the surface of the material is disturbed. By controlling this deviation, the surface can be formed into a crepe shape. If the pressing force is small, the surface of the material is disturbed by the gas, and when the pressing force is high, the surface of the material becomes smooth. When the pressing force is applied at 2000 DEG C or lower, the graphite plate 5 becomes not homogeneous.

Since the thermal energy acts on the surface, there is a time difference in recrystallization between the surface and the inside, whereby the surface can be formed into a crepe shape while maintaining the crystallinity as a whole.

During the heat treatment of the polymer film 3, the temperature may be once lowered to room temperature and divided into two steps between the step of releasing oxygen, nitrogen and hydrogen and the step of recrystallizing carbon.

The polymer film 3 is provided in the heat-resistant container 1. However, in order to increase the number of treatments per one time, a carbon plate 4 having a thickness of about 5 mm may be stacked on the heat-resistant container 1 shown in Fig. 2 . 2 is a sectional view of the heat-resistant container 1 placed in a furnace.

(Heat-resistant container 1 and block 2)

The heat-resistant container 1 and the block 2 are both made of a material that can withstand at least 3200 占 폚 and does not generate impurities. Further, since the polymer film 3 must have a structure capable of being pressed, it must withstand 100 kg / cm < ² >.

The shape of the heat-resistant container 1 and the block 2 is not necessarily limited to a square shape or a circular shape. It is necessary that there is no temperature variation within the heat-resistant container 1, and it is preferable that the carbon material is free of impurities.

(Inert gas)

At the time of heat treatment, an inert gas is used in order not to oxidize the heat-treated product. Helium, nitrogen, especially argon, is preferred. The gas pressure may be a positive pressure higher than the normal pressure in order to prevent the air from entering the furnace. However, if the gas pressure in the furnace is higher than 0.2 MPa, the off gas of oxygen, nitrogen and hydrogen hardly comes out. Further, if the gas pressure in the furnace is low, the discharge of the leaving gas abruptly occurs, and the surface is destroyed.

In addition, even if it is not destroyed, the generation of the leaving gas becomes uneven and the homogeneity is impaired. Further, the thicker the polymer film 3 used as the raw material, the more difficult it is for the escape gas to escape. This tendency is strong.

(Example)

Samples were prepared and evaluated. Conditions and results are shown in Table 1. However, since the fourth embodiment is merely a modification of the method of stacking the raw materials, it is not described in Table 1.

(Example 1)

30 sheets of a polyimide film (Capton 100H manufactured by DuPont-Du Pont Co., Ltd., thickness: 25 占 퐉) were cut into 100 mm ² and 30 sheets were stacked and placed in a heat- resistant container 1 shown in Fig. The temperature was raised to 1000 deg. C at 1 degree / minute. Thereafter, oxygen, nitrogen, and hydrogen were removed, and the pressure was increased to 50 ° C / cm ² while raising the temperature to 3,000 ° C at 10 ° / min in an argon gas atmosphere. Thus, a graphite plate 5 was produced. The graphite plate 5 produced by this method had a surface roughness of 16.3 占 퐉 and a flatness of 0.040%. The thermal conductivity was 1160 W / mK. However, the temperature of the thermocouple 6 was 124 占 폚, and the evaluation was?.

(Example 2)

(Capton 200H thickness 50 占 퐉, made by DuPont-Toray Co., Ltd.) having a thickness of 50 占 퐉 was cut into 100 mm ² and 30 sheets were stacked and placed in a heat-resistant container 1 shown in Fig. 1 and heated in an atmosphere of nitrogen gas at 450 占 폚 or higher and 650 占 폚 or lower The temperature was raised to 1000 ° C. at 1 ° C./min to remove oxygen, nitrogen and hydrogen. Thereafter, the temperature was raised to 3000 ° C. at 10 ° C./min in an argon gas atmosphere, and the pressure was increased to 80 kg / cm ^{2 to} obtain graphite plate 5 ). The graphite plate 5 produced by this method had a surface roughness of 19.5 占 퐉 and a flatness of 0.061%. The thermal conductivity was 1030 W / mK. The temperature of the thermocouple 6 was 98 占 폚, and the evaluation was "?".

(Example 3)

30 sheets of a polyimide film (Capton 300H thickness 75 μm, manufactured by Du Pont, Toray Co., Ltd.) was cut into 100 mm ² , and 30 sheets were stacked and placed in a heat-resistant container 1 shown in FIG. 1 and heated in an atmosphere of nitrogen gas at 450 ° C. to 650 ° C. / min to the temperature was raised at the then temperature was raised to 1000 ℃ and, leaving the oxygen, nitrogen, hydrogen, argon atmosphere a 10 ° / min to 3000 ℃ subjected to the pressure of 100kg / cm ^2, to thereby prepare a graphite plate 5 . The graphite plate 5 produced by this method had a surface roughness of 24.7 占 퐉 and a flatness of 0.083%. The thermal conductivity was 900 W / mK. The temperature of the thermocouple 6 was 90 占 폚, and the evaluation was "?".

(Example 4)

3 pieces of a polyimide film (Capton 100H thickness 25 占 퐉, manufactured by DuPont-Toray Co., Ltd.) were cut to 100 mm ² and 30 sheets were stacked. Four carbon plates having a thickness of 5 mm were sandwiched therebetween and placed in a heat- (2). The temperature was raised to 1000 deg. C at 450 deg. C or higher and 650 deg. C or lower in an atmosphere of nitrogen gas using an electric furnace to remove oxygen, nitrogen, and hydrogen. The temperature was raised, and the pressure was increased to 50 kg / cm ² to prepare a graphite plate (5). The measurement was carried out to find that the thermal conductivity was 1120 W / mK, the surface roughness was 16.0 m, the flatness was 0.045%, the temperature of the thermocouple 6 was 109 deg.

(Comparative Example 1)

In the manufacturing method of Patent Document 1, a polyimide film (Capton 100H thickness 25 μm, manufactured by DuPont-Toray Co., Ltd.) having a thickness of 25 μm was cut into 100 mm ² , 30 sheets were stacked and placed in the heat resistant container 1 shown in FIG. The temperature was raised to 3000 ° C in an argon gas atmosphere, and the pressure was applied at 300 kg / cm ² to prepare a graphite plate (5). The graphite plate 5 produced by this method had a surface roughness of 1.0 占 퐉 and a flatness of 0.005%, and the surface thereof was a glossy surface. The thermal conductivity is 1360 W / mK, which is higher than in Examples 1 to 3. However, the temperature of the thermocouple 6 was 67 ° C, and the evaluation was "x".

This is considered to be because the surface is not formed in a crepe shape and the contact point to the counterpart member is small, so that the contact resistance loss is increased.

(Comparative Example 2)

In the manufacturing method of Patent Document 2, a polyimide film (Capton 200H thickness 75 μm, manufactured by DuPont-Toray Co., Ltd.) having a thickness of 75 μm was cut into 100 mm ² and 30 sheets were superimposed and placed in the heat resistant container 1 shown in FIG. Deg.] C to remove oxygen, nitrogen, and hydrogen. Thereafter, the temperature was raised to 3000 deg. C in an argon gas atmosphere at no pressure to prepare a graphite plate. The graphite plate produced by this method had a surface roughness of 40.0 占 퐉 and a flatness of 0.145%, and the surface thereof was an opaque glass-like non-glossy surface. The thermal conductivity was 780 W / mK, the temperature of the thermocouple 6 was 62 ° C, and the evaluation was "x".

This is considered to be because the graphite plate destroyed the two-dimensional crystal structure of the hexagonal mesh shape. This is also shown in the lowering of the thermal conductivity. Further, it is considered that breaking the two-dimensional crystal structure makes it impossible to have elasticity and contact with the counterpart member.

(Comparative Example 3)

In the manufacturing method of Patent Document 2, a polyimide film (Capton 300H thickness 75 μm, manufactured by DuPont-Toray Co., Ltd.) having a thickness of 75 μm was cut into 100 mm ² and 30 sheets were superimposed and placed in a heat resistant container 1 shown in FIG. Deg.] C to remove oxygen, nitrogen, and hydrogen. Thereafter, the temperature was raised to 3000 deg. C in an argon gas atmosphere at no pressure to prepare a graphite plate. The graphite plate produced by this method had a surface roughness of 60.5 占 퐉 and a flatness of 0.18%, and the surface thereof was an opaque glass-like non-glossy surface. The thermal conductivity is 650 W / mK, which is lower than those of Examples 1 to 3. The temperature of the thermocouple 6 was 59 占 폚, and the evaluation was "占".

This is considered to be because the graphite plate destroyed the two-dimensional crystal structure of the hexagonal mesh shape. This is also shown in the lowering of the thermal conductivity. Further, it is considered that breaking the two-dimensional crystal structure makes it impossible to have elasticity and contact with the counterpart member.

(Comparative Example 4)

In the manufacturing method of Patent Document 2, a polyimide film (Capton 300H thickness 75 μm, manufactured by DuPont-Toray Co., Ltd.) having a thickness of 75 μm was cut into 100 mm ² and 30 sheets were superimposed and placed in a heat resistant container 1 shown in FIG. Deg.] C to remove oxygen, nitrogen, and hydrogen. Thereafter, the temperature was raised to 3000 deg. C in an argon gas atmosphere at no pressure to prepare a graphite plate. The graphite plate produced by this method had a surface roughness of 73.0 占 퐉 and a flatness of 0.195%, and the surface thereof was an opaque glass-like non-glossy surface. The thermal conductivity is 500 W / mK, which is lower than those of Examples 1 to 3. The temperature of the thermocouple 6 was 50 占 폚, and the evaluation was "占".

This is considered to be because the graphite plate destroyed the two-dimensional crystal structure of the hexagonal mesh shape. This is also shown in the lowering of the thermal conductivity. Further, it is considered that breaking the two-dimensional crystal structure makes it impossible to have elasticity and contact with the counterpart member.

(Evaluation of graphite plate 5)

3 shows the surface photograph of the graphite plate 5 and the laser shape measurement. The surface roughness is evaluated by the following (1) surface roughness, (2) flatness and (3) contact resistance. That is, evaluation is made based on (1) surface roughness with regularity, (2) flatness with irregular unevenness, and (3) contact resistance as a result of thermal characteristics. (1) (2) Both surface properties are required to lower the contact resistance 3 of the surface heat.

(1) Evaluation of surface roughness

And evaluated by Ra (arithmetic mean roughness) of JIS standard.

(2) Definition of flatness

Fig. 4 shows a cross section of the graphite plate 5. Fig. Percentage of the difference between the maximum height and the minimum height (Amm) divided by 80 mm within a distance of 80 mm represents the flatness.

(3) Evaluation of contact thermal resistance

The cross-sectional structure shown in Fig. 5 is used in order to see the effect of heat transfer by the reduction in contact thermal resistance. A thermocouple 6 is attached to the end of a 100 mm x 30 mm graphite plate 5 is prepared. The copper block 7 of 30 mm ² heated to 300 캜 was placed at the opposite position to the thermocouple 6 and the temperature was measured at the thermocouple 6 after 5 seconds. If the contact thermal resistance is small, the heat transfer is accelerated, and the measured temperature at the thermocouple 6 rises quickly. The evaluation was made such that the temperature of the thermocouple 6 was 110 DEG C or higher, "?&Quot;, 90 DEG C or more and less than 110 DEG C or less, " DELTA "

<Result>

The results of Examples 1 to 3 and Comparative Examples 1 to 4 are summarized in the graph of Fig. 6 shows the surface roughness on the vertical axis and the flatness on the horizontal axis. The surface roughness is the average unevenness, and the flatness is the unevenness of the portion where the change is most intense. Therefore, the surface roughness and the flatness are not directly related to each other.

However, in the case of this material, only a certain range is proportional to the surface roughness and flatness. The characteristics of the contact thermal resistance within the range are also good.

From this graph, the range of the surface roughness is 10 μm or more, less than 40 μm, the flatness, the range of 0.010% or more and 0.135% or less is discontinuous (specific range, critical range) with other areas. Further, it is preferable that the range is 16.3 占 퐉 or more, 24.7 占 퐉 or less, and the flatness is 0.04% or more and 0.09% or less in the range of the embodiment and the surface roughness.

7 shows the relationship between the contact thermal resistance and the thermal conductivity. In the comparative example, when the thermal conductivity is high, the contact thermal resistance is not increased to some extent. This is presumably because the crystallinity of the graphite is increased to improve the heat transfer rate, but the contactability is deteriorated. On the other hand, in the embodiment, as a result of surface roughness and flatness in the range shown in Fig. 6, the thermal conductivity has a certain height and the contact thermal resistance has also increased. As a result, the performance of transferring heat from the object is high. The surface roughness and the flatness of the surface were found to be more critical than those of the comparative example. This phenomenon can not be predicted.

This is not related to the thickness of the graphite plate 5.

[Industrial Availability]

It is used as a heat conduction material inside a device due to high performance and miniaturization of electronic devices, particularly in notebook computers, tablets, smart phones, mobile phones, wearable devices, digital cameras, and digital movie cameras. Also, it is used for industrial equipment exceeding the heat resistance limit of the heat conduction paste used for reducing contact thermal resistance loss, outdoor use equipment including ultraviolet rays, and the like.

1: heat-resistant container 2: block
3: polymer film 4: carbon plate
5: graphite plate 6: thermocouple
7: Copper block

Claims (6)

The surface roughness (Ra) of the graphite plate is 10 占 퐉 or more and less than 40 占 퐉,
Wherein a rate of change of surface irregularities with respect to a distance of 80 mm is not less than 0.01% and not more than 0.135%, within an arbitrary distance of 80 mm in the surface of said graphite plate. The method according to claim 1,
A graphite plate having a thickness of 25 占 퐉 or more and 2 mm or less, obtained by heat-treating one or more polymer films having a thickness of 25 占 퐉 or more and 150 占 퐉 or less. The method according to claim 1,
The thermal conductivity of the surface direction, is less than 700W / mK or more, 1500W / mK,, graphite plate density of 1.0g / cm ³ or more, 2.2g / cm ³ or less. The method according to claim 1,
The thermal conductivity in the thickness direction, 2W / mK or more, 20W / mK or less and a density of 1.0g / cm ³ or more, 2.2g / cm ³ or less, a graphite plate. A process for producing a graphite plate in which a polymer film is heat-treated in an inert gas,
Heat treatment is performed on the polymer film, in an atmosphere of the inert gas, and the temperature is less than 2400 ℃, 3200 ℃, the temperature is at least 2000 ℃ to a pressure of 10kg / cm ² or more, 100kg / cm ² or less, a graphite plate &Lt; / RTI &gt; The method of claim 5,
The raw material polymer may be at least one selected from the group consisting of polyimide, polyamide, polyoxadiazole, polybenzothiazole, polybenzobisthiazole, polybenzoxazole, polybenzobisoxazole, polyparaphenylene vinylene, Wherein the polymer film is a condensation polymer film such as polydimethylsiloxane, diol, polyphenylenebenzobisimidazole, polythiazole, and the like.

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