KR102406281B1 - Carbon composite material - Google Patents

Abstract

A carbon composite member 1 in which a thermally decomposed carbon layer 3 is formed on a graphite substrate 2, wherein a plurality of thermally decomposed carbon clusters 4 are formed on at least a part of the surface of the thermally decomposed carbon layer 3 .

Description

Carbon Composite Member {CARBON COMPOSITE MATERIAL}

The present invention relates to a carbon composite member.

BACKGROUND ART Carbon materials such as graphite have excellent chemical stability, heat resistance, and mechanical properties, and are therefore used in many fields such as semiconductor manufacturing, chemical industry, machinery, and nuclear power. Moreover, since graphite itself is a porous body, since it is easy to adsorb|suck gas, moisture, an impurity, etc. inside a pore, it is easy to contaminate the inside of a pore. Therefore, there is known a technique for reducing the adverse effect of graphite by coating the pyrolytic carbon so that these contaminants are not re-emitted from the pores.

The pyrolytic carbon is hard and forms a dense film with gas impermeability, so it is particularly suitable for use in a high-purity environment. Moreover, in recent years, the semiconductor manufacturing apparatus is enlarged, and the components for apparatuses are also enlarged. Here, in Patent Document 1, a large-sized graphite material coated with pyrolytic carbon is liable to fall during handling. As a countermeasure, a pyrolytic carbon layer is formed on a carbon substrate, and a carbon-based powder is formed on the surface. A carbon composite member has been proposed in which a plurality of protrusions obtained by crystal growth of pyrolytic carbon are formed around the nuclei to prevent slipping by performing an anti-slip process and improve workability.

Japanese Patent Laid-Open No. 2008-222456

However, since the carbon composite member described in Patent Document 1 forms projections obtained by crystal growth of pyrolytic carbon by using the carbon-based powder as the nucleus, when an impact is applied to the carbon composite member and the projections are damaged, the carbon-based powder as the nucleus cracks are more likely to reach In addition, since the carbon-based powder is placed on the substrate, the cracks penetrate the pyrolytic carbon layer and cause leakage.

In the present invention, in view of the above problems, a carbon composite member in which a pyrolytic carbon layer is formed on a graphite substrate, has an anti-slip function, and a carbon composite member in which cracks are difficult to penetrate through the pyrolytic carbon layer even when an impact is applied. intended to provide

The carbon composite member according to the present invention for solving the above problems is as follows.

(1) a carbon composite member in which a pyrolytic carbon layer is formed on a graphite substrate,

A carbon composite member characterized in that a plurality of clusters of pyrolytic carbon are formed on at least a part of the surface of the pyrolytic carbon layer.

According to the carbon composite member according to the present invention, a plurality of clusters of pyrolytic carbon are formed on at least a part of the surface of the pyrolytic carbon layer, and the presence of the clusters forms protrusions on the surface of the pyrolytic carbon layer, Therefore, there is a high anti-slip effect. In addition, since the pyrolytic carbon clusters only adhere to the surface of the pyrolytic carbon layer, cracks penetrating the pyrolytic carbon layer are unlikely to occur even if the clusters are peeled off.

Further, even if the carbon composite member according to the present invention is adhered to other members during use thereof, only clusters of pyrolytic carbon on the surface of the pyrolytic carbon layer are adhered, so that it is easily separable from other members, and the pyrolytic carbon is adhered to. The damage to the layer is reduced.

Further, the carbon composite member according to the present invention preferably has the following aspects (2) to (5).

(2) The cluster is a deposit obtained by the CVD method.

When the cluster of pyrolytic carbon is a deposit obtained by the CVD method, since it is the same material as the pyrolytic carbon layer, internal stress is unlikely to occur and it is difficult to become a source of cracks.

(3) The cluster has a maximum diameter of 10 to 50 µm.

When the maximum diameter of the cluster of pyrolytic carbon is within the above range, the dimensional accuracy of the carbon composite member is high, and the anti-sticking and anti-slip effects are favorably exhibited.

(4) The arithmetic mean roughness Ra on the surface of the pyrolytic carbon layer is 1 to 3 µm.

When the arithmetic surface roughness Ra on the surface of the pyrolytic carbon layer is within the above range, it is difficult for the clusters to be buried in the pyrolytic carbon layer, and the prevention of sticking and the anti-slip effect are likely to be exhibited. Moreover, the influence on the dimensions of the carbon composite member is small, and it can be used as a carbon composite member with high dimensional accuracy.

(5) The thickness of the pyrolytic carbon layer is 5 to 200 µm.

When the thickness of the pyrolytic carbon layer is 5 µm or more, the unevenness of the graphite substrate, which is a porous body, can be sufficiently covered, and the gas impermeability can be ensured. In addition, when the thickness of the pyrolytic carbon layer is 200 μm or less, warpage or peeling due to thermal deformation between the graphite substrate and the pyrolytic carbon layer can be prevented.

According to the carbon composite member according to the present invention, a plurality of clusters of pyrolytic carbon are formed on at least a part of the surface of the pyrolytic carbon layer, and the presence of the clusters forms protrusions on the surface of the pyrolytic carbon layer, Therefore, there is a high anti-slip effect. In addition, since the pyrolytic carbon clusters only adhere to the surface of the pyrolytic carbon layer, cracks penetrating the pyrolytic carbon layer are unlikely to occur even if the clusters are peeled off.

Further, even if the carbon composite member according to the present invention is adhered to other members during use thereof, only clusters of pyrolytic carbon on the surface of the pyrolytic carbon layer are adhered, so that it is easily separable from other members, and the pyrolytic carbon is adhered to. The damage to the layer is reduced.

1 is a schematic cross-sectional view of a carbon composite member according to an embodiment of the present invention.
2 is a scanning electron microscope photograph of the surface of the carbon composite member obtained in Example 1. FIG.
3 is a scanning electron microscope photograph of the surface of the carbon composite member obtained in Comparative Example 1. FIG.

(Detailed Description of the Invention)

1 is a schematic cross-sectional view of a carbon composite member according to an embodiment of the present invention. In the carbon composite member 1 according to the present embodiment, a thermally decomposed carbon layer 3 is formed on a graphite substrate 2 , and clusters of thermally decomposed carbon are formed on at least a part of the surface of the thermally decomposed carbon layer 3 . (4) That is, a plurality of deposits of particles using pyrolytic carbon as a raw material are formed.

Therefore, in the outermost surface of the carbon composite member 1 according to the present embodiment, protrusions are formed on the surface of the pyrolytic carbon layer 3 due to the presence of the clusters 4 of pyrolytic carbon, and thus the surface becomes rough. It has an anti-slip effect. Further, since the pyrolytic carbon clusters 4 are only attached to the surface of the pyrolytic carbon layer 3, cracks penetrating the pyrolytic carbon layer 3 are less likely to occur even if the clusters 4 are peeled off.

Furthermore, even if the carbon composite member 1 according to the present embodiment is adhered to other members during its use, only the clusters 4 of pyrolytic carbon on the surface of the pyrolytic carbon layer 3 are adhered. , can be easily separated from other members, and damage to the pyrolytic carbon layer 3 is reduced.

The cluster 4 of pyrolytic carbon is preferably a deposit obtained by the CVD method. As the pyrolytic carbon cluster 4 is a deposit obtained by the CVD method, since it is the same material as the pyrolytic carbon layer 3, internal stress is unlikely to occur and it is unlikely to become a source of cracks.

The cluster 4 of pyrolytic carbon preferably has a maximum diameter of 10 to 50 µm. If the maximum diameter of the cluster 4 of pyrolytic carbon is 10 µm or more, the cluster 4 is less likely to be buried in the pyrolytic carbon layer 3, and the prevention of sticking and the anti-slip effect are likely to be exhibited. On the other hand, when the maximum diameter of the cluster 4 of pyrolytic carbon is 50 µm or less, the influence on the dimensions of the carbon composite member 1 is small, and it can be used as a member with high dimensional accuracy.

For this reason, when the maximum diameter of the cluster 4 of pyrolytic carbon is 10-50 micrometers, the dimensional accuracy is high and the carbon composite member 1 which exhibits the anti-sticking and anti-slip effect favorably can be provided. Moreover, in order to exhibit these effects more favorably, it is more preferable that the maximum diameter of the cluster 4 of pyrolysis carbon is 20-40 micrometers.

In addition, the magnitude|size (size) of the cluster 4 of pyrolysis carbon can be measured as follows.

The size of the clusters 4 of pyrolytic carbon may be measured as it is by measuring the clusters 4 attached to the surface of the pyrolytic carbon layer 3, or when the number of clusters 4 is large and individual clusters 4 cannot be discriminated, the clusters ( 4) Remove and check. When checking by peeling off the cluster 4, it can fix to the surface of an adhesive tape, enlarge it with an electron microscope, and can measure a size.

When measuring by fixing the peeled cluster 4 to the surface of the adhesive tape, a clear image can be obtained by using a conductive double-sided tape or by depositing gold to ensure the conductivity of the sample.

In addition, since the pyrolytic carbon cluster 4 grows in a flat plate shape, it adheres to the surface of the pyrolytic carbon layer 3 in a planar shape. Therefore, the peeled off clusters 4 of pyrolytic carbon are adhered to the surface of the conductive tape in a planar shape. In addition, when measuring the size of the cluster 4 of pyrolysis carbon, if it is the size of the longest direction, for example, if it is an ellipse, let the long axis be the largest diameter.

Subsequently, as an index indicating a state in which a plurality of clusters 4 of pyrolytic carbon are formed, that is, a state in which the clusters 4 are dotted, expressed by the arithmetic mean roughness Ra on the surface of the pyrolytic carbon layer 3 . can In the carbon composite member 1 according to the present embodiment, it is preferable that the arithmetic mean roughness Ra = 1 to 3 µm.

When the arithmetic surface roughness Ra is 1 µm or more, the cluster 4 is less likely to be buried in the pyrolytic carbon layer 3, and the prevention of sticking and the anti-slip effect are likely to be exhibited. On the other hand, when the arithmetic mean roughness Ra is 3 µm or less, the influence on the dimensions of the carbon composite member 1 is small, and it can be used as a member with high dimensional accuracy.

In addition, arithmetic mean roughness Ra can be measured based on JISB0031.

In addition, in this embodiment, when calculating|requiring the said arithmetic mean roughness Ra, let the reference length be 0.5 mm, and the average value of the arithmetic mean roughness Ra measured at 3 arbitrary places in the surface of the pyrolysis carbon layer 3 to judge with

It is preferable that the thickness of the thermal decomposition carbon layer 3 is 5-200 micrometers. When the thickness of the pyrolytic carbon layer 3 is 5 μm or more, the unevenness of the graphite substrate 2 as a porous body can be sufficiently covered, and it becomes difficult to adsorb gas, moisture, impurities, etc. inside the pores, and the fire of these gases and impurities penetration can be ensured. On the other hand, when the thickness of the pyrolytic carbon layer 3 is 200 μm or less, warpage and peeling due to thermal deformation of the pyrolytic carbon layer 3 can be prevented.

In order to exhibit these effects more favorably, as for the thickness of the thermally decomposed carbon layer 3, 10-100 micrometers is more preferable, and its 20-50 micrometers are still more preferable.

In addition, the thickness of the thermally decomposed carbon layer 3 can be measured using a polarization microscope, a scanning electron microscope, etc. from comparison with a standard scale. When a standard scale is already displayed with a scanning electron microscope or the like, it can be used to calculate the thickness.

Moreover, as the graphite base material 2 in the carbon composite member 1 which concerns on this embodiment, it is preferable that it is an isotropic graphite material. Since isotropic graphite has small anisotropy in properties, the difference in the coefficient of thermal expansion with the pyrolytic carbon layer 3 is small depending on location and direction, so that it is difficult to peel off.

Subsequently, the carbon composite member 1 according to the present embodiment can be obtained, for example, as follows.

First, the graphite base material 2 of the target shape is prepared. When the pyrolytic carbon layer 3 is formed on the graphite substrate 2, it becomes larger by the thickness, so that it is relatively thinly processed according to the final thickness as the carbon composite member 1 or the thickness of the pyrolytic carbon layer 3 to be formed. desirable. In addition, in order to improve adhesiveness with the pyrolytic carbon layer 3, you may process the surface of the graphite base material 2 to a rough surface.

Then, the graphite base material 2 is placed in the CVD furnace, and the raw material gas is introduced after raising the temperature to the film formation temperature. Although the film-forming temperature is not specifically limited, For example, it can be 800-2000 degreeC. The raw material gas for obtaining the pyrolysis carbon layer 3 will not be specifically limited if it is a hydrocarbon. For example, in addition to alkanes such as methane, ethane, propane, and butane, alkenes such as ethylene and propylene, and alkynes such as acetylene, aromatic raw material gases such as benzene and toluene may be used.

And the thermal decomposition carbon layer 3 is formed into a film on the surface of the graphite base material 2 by maintaining the film-forming temperature and introduce|transducing the source gas for a fixed period of time. In addition, as the carrier gas, an inert gas such as Ar can be used.

Subsequently, at a stage in which the pyrolysis carbon layer 3 has a predetermined thickness, clusters 4 of pyrolysis carbon are generated on the surface of the pyrolysis carbon layer 3 . The clusters 4 of pyrolytic carbon are generated when particles (small lumps) of pyrolytic carbon generated in the air settle on the surface of the pyrolytic carbon layer 3 and are deposited (that is, deposited).

Although the method of generating this cluster 4 is not specifically limited, For example, by raising the pressure in a CVD furnace, raising the temperature, or raising the partial pressure of hydrocarbon, the balance of the thermal decomposition reaction is temporarily disrupted. It is possible to form a plurality of clusters 4 of pyrolytic carbon on the surface of the pyrolytic carbon layer 3 by releasing and accelerating thermal decomposition, generating particles of pyrolytic carbon in the air, and depositing them.

In addition, since particles of pyrolytic carbon not only occur in the upper space of the pyrolysis carbon layer 3 but also grow even after falling on the surface of the pyrolysis carbon layer 3, particles of pyrolysis carbon are generated in the pyrolysis carbon layer 3 It is integrated with the pyrolysis carbon layer 3 while being deposited on the surface. That is, the pyrolytic carbon layer 3 and the cluster 4 of pyrolytic carbon formed on the surface are integrated.

As an example of the conditions for generating and depositing these pyrolytic carbon particles, the pressure in the CVD furnace is 10 to 10000 Pa, and the temperature is 800 to 2000°C.

In addition, in order to deposit more pyrolytic carbon particles on the surface of the pyrolytic carbon layer 3, in the CVD furnace, the space above the pyrolytic carbon layer 3 is made wider. If the upper space is large, the amount of generated pyrolytic carbon particles increases, so that more pyrolytic carbon particles can be deposited on the surface of the pyrolytic carbon layer 3 to be integrated.

Furthermore, by applying an electric charge to the graphite substrate 2 or inverting the graphite substrate 2 in a CVD furnace, not only the upper surface of the thermally decomposed carbon layer 3 but also the side surface and the lower surface of the graphite substrate 2 are thermally decomposed. The carbon layer 3 may be formed and the clusters 4 may be interspersed.

The clusters 4 integrated and adhered to the surface of the pyrolytic carbon layer 3 obtained in this way are attached at the end of the film formation of the pyrolytic carbon layer 3, so the disturbance in the crystal direction of the pyrolytic carbon layer 3 is extremely It is limited to the surface and does not significantly affect the internal structure. Therefore, even when a force is applied to peel the clusters 4 of pyrolytic carbon, damage to the pyrolytic carbon layer 3 is small, airtightness by the pyrolytic carbon layer 3 is secured, and the graphite substrate 2 is Adsorption and release of gases or impurities can be prevented.

(Form for implementing the invention)

Hereinafter, an Example and a comparative example are given and further demonstrated so that the characteristic of the carbon composite member which concerns on this invention may be made clear.

(Example 1)

The isotropic graphite material was processed so that it might become a size of 50x50x5 mm, and it was set as the graphite base material. The obtained graphite substrate was placed in a CVD furnace, heated to 1200° C. or higher while reducing pressure with a vacuum pump, and a raw material gas containing hydrocarbons was supplied so that the gas pressure in the CVD furnace was 1 kPa or less, and the formation of a pyrolytic carbon layer was started.

Then, when the time for which the thickness of the thermal decomposition carbon layer grows to 20 micrometers has reached|attained, supply of the source gas was stopped abruptly.

In addition, since the raw material gas is supplied from the high-pressure cylinder into the reduced-pressure furnace at the time of supplying it into the furnace, it rapidly takes heat and expands to cool the furnace. For this reason, if the supply of the raw material gas is abruptly stopped, the cooling capacity is lowered, and the atmosphere in the furnace having a small heat capacity under reduced pressure is temporarily heated to create an environment in which clusters forming projections are likely to occur. Temporarily generated clusters are deposited on the pyrolysis carbon layer.

In this way, particles of pyrolytic carbon formed in the air were deposited on the surface of the pyrolytic carbon layer. In addition, the presence or absence of such an instantaneous temperature fluctuation of such a lean atmosphere gas is difficult to detect with a thermocouple radiation thermometer, and it can be confirmed by the presence or absence of generation|occurrence|production of the cluster of pyrolysis carbon.

The surface of the carbon composite member thus obtained was confirmed with a scanning electron microscope (SEM). The photographed scanning electron micrograph (magnification: 500 times) is shown in FIG. In FIG. 2 , it can be seen that small lumps in the figure are clusters of pyrolysis carbon, and clusters of pyrolysis carbon are formed dotted with and plural on the surface of the pyrolysis carbon layer having a large-diameter hemispherical shape in the figure. In addition, it can be seen that the particles of the pyrolytic carbon are not removed by the above-described washing, but are integrated with the pyrolytic carbon layer. Also, from the same photograph (refer to the scale in the lower left), it can be read that the maximum diameter of the cluster is in the range of 10 to 50 μm.

Further, using a surface roughness meter conforming to JIS B 0031, the arithmetic mean roughness Ra was measured at three arbitrary locations on the surface of the pyrolytic carbon layer. μm.

Although the friction on the surface was confirmed by wearing dustproof gloves made of latex for this carbon composite member, it was confirmed that it could be sufficiently held even when a strong force was applied.

(Comparative Example 1)

A carbon composite member was formed in the same manner as in Example 1. However, after the formation of the pyrolytic carbon layer, the supply of the raw material gas was gradually narrowed over 10 minutes. For this reason, it is thought that the rapid temperature rise by the supply stop of the raw material gas was leveled, and generation|occurrence|production of a cluster did not occur.

The surface of the carbon composite member thus obtained was confirmed with a scanning electron microscope (SEM). The photographed scanning electron micrograph (magnification: 500 times) is shown in FIG. In Fig. 3, the surface of the carbon composite member showed a smooth growth surface that grew in a sector shape from the nucleus on the base side, and no clusters of pyrolytic carbon were observed.

In addition, when the arithmetic mean roughness Ra was measured at three arbitrary locations on the surface of the pyrolytic carbon layer using a surface roughness meter conforming to JIS B 0031, they are 0.795 µm, 1.049 µm, and 0.753 µm, respectively, and 0.87 as an average thereof. μm.

It was confirmed that this carbon composite member was slidable only by friction on the surface and could not be sufficiently held when a strong force was applied to this carbon composite member while wearing dustproof gloves made of latex and gripping the surface on which the pyrolytic carbon layer was formed.

In addition, this invention is not limited to embodiment mentioned above, A deformation|transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, etc. of each component in the above-mentioned embodiment are arbitrary, as long as this invention can be achieved, and it is not limited.

Since the carbon composite member according to the present invention has an anti-slip function, it is difficult to drop even as a large device component, has good handling properties, and furthermore, cracks hardly penetrate the thermally decomposed carbon film even when an impact is applied. , semiconductor manufacturing, chemical industry, machinery, nuclear power, etc. are effective across many fields.

1: carbon composite member
2: Graphite substrate
3: pyrolysis carbon layer
4: cluster

Claims (5)

A carbon composite member in which a pyrolytic carbon layer is formed on a graphite substrate,
A plurality of clusters of pyrolytic carbon are formed on at least a part of the surface of the pyrolytic carbon layer,
The carbon composite member characterized in that the arithmetic mean roughness Ra on the surface of the thermally decomposed carbon layer is 1 to 3 µm. The carbon composite member according to claim 1, wherein the cluster is a deposit obtained by a CVD method. The carbon composite member according to claim 1 or 2, wherein, among the clusters, the largest cluster has a size in the longest direction of 10 to 50 µm. The carbon composite member according to claim 1 or 2, wherein the pyrolytic carbon layer has a thickness of 5 to 200 µm. delete

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