阅读说明：本技术 碳复合构件 (Carbon composite member ) 是由 北口比吕 伊藤敏树 于 2021-05-20 设计创作，主要内容包括：本发明提供一种碳复合构件,其具有覆盖整个石墨基材且牢固的热解碳层。一种碳复合构件,其是在石墨基材(1)上形成有2层以上的热解碳层的碳复合构件,其中,在一个热解碳层即第1层(2A)和与其相邻的其他热解碳层即第2层(2B)的边界处具有存在气孔(3)的气孔区域(4)。(The invention provides a carbon composite member having a strong pyrolytic carbon layer covering the entire graphite substrate. A carbon composite member having 2 or more pyrolytic carbon layers formed on a graphite substrate (1), wherein a pore region (4) having pores (3) is provided at the boundary between a 1 st layer (2A) which is one pyrolytic carbon layer and a 2 nd layer (2B) which is another pyrolytic carbon layer adjacent thereto.)

1. A carbon composite member comprising a graphite substrate and at least 2 pyrolytic carbon layers formed thereon, wherein a pore region having pores is formed at the boundary between one pyrolytic carbon layer and another pyrolytic carbon layer adjacent thereto.

2. The carbon composite member according to claim 1,

when the pyrolytic carbon layers of 2 or more are sequentially arranged as a 1 st layer, a 2 nd layer, an (n-1) th layer and an (n) th layer from the side close to the graphite substrate,

the 1 st layer has a 1 st opening portion, the n-th layer has an n-th opening portion, and

the 1 st opening and the n-th opening are formed at different positions with respect to the graphite base material.

3. The carbon composite member according to claim 2, wherein the 2 nd layer covers the 1 st opening, and the pore region of the boundary of the 1 st layer and the 2 nd layer at the periphery of the 1 st opening extends obliquely toward the graphite base material.

4. The carbon composite member according to claim 2 or 3, wherein the pore region is provided at a boundary of the nth layer and the (n-1) th layer immediately below the nth layer, and the nth layer is gradually thinned toward the nth opening portion.

5. The carbon composite member according to any one of claims 1 to 3, wherein the pore has a maximum pore diameter of 0.5 μm to 3.0 μm.

6. The carbon composite member according to any one of claims 1 to 3, wherein the total thickness of the 2 or more pyrolytic carbon layers is 5 to 400 μm.

7. The carbon composite member according to any one of claims 1 to 3, wherein the graphite substrate is an isotropic graphite material.

Technical Field

The present invention relates to a carbon composite member.

Background

Carbon materials such as graphite are excellent in chemical stability, heat resistance, and mechanical properties, and therefore are used in many fields such as semiconductor manufacturing, chemical industry, machinery, and atomic energy. Further, since graphite itself is a porous body, gas, moisture, impurities, and the like are easily adsorbed in the pores, and thus the inside of the pores is easily contaminated. Therefore, there is known a technique of reducing the adverse effect of graphite by applying pyrolytic carbon so that these contaminants are not released from the pores again.

Pyrolytic carbon forms a hard, gas impermeable, dense film and is therefore particularly suitable for use in high purity environments.

Patent document 1 describes, as such an application, a member for a semiconductor manufacturing apparatus, which is made of a carbon material, has a pyrolytic carbon layer formed on at least a surface in contact with a raw material gas, and has a wetting tension of 62.0mN/m or more on the surface in contact with the raw material gas.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2007-12933

Disclosure of Invention

Problems to be solved by the invention

However, the above-described technology relates to a semiconductor manufacturing apparatus for a small wafer, and in order to prevent adsorption of gas, moisture, and impurities to the inside and release of these components, it is necessary to cover the entire surface of a carbon material such as a graphite substrate by blocking a support point generated at the time of coating, and in particular, in a large-sized carbon composite member, it is necessary to prevent peeling due to an increase in impact applied to a coating layer of pyrolytic carbon at the time of handling.

In view of the above problems, an object of the present invention is to provide a carbon composite member having a strong pyrolytic carbon layer covering the entire graphite substrate.

Means for solving the problems

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

(1) A carbon composite member having a pyrolytic carbon layer of 2 or more layers formed on a graphite substrate,

the carbon layer has a pore region where pores are present at a boundary between one pyrolytic carbon layer and another pyrolytic carbon layer adjacent thereto.

According to the carbon composite member of the present invention, since the pyrolytic carbon layer is composed of a plurality of layers, the effect of preventing adsorption and desorption of gas, moisture, and impurities in the graphite base material can be enhanced.

On the other hand, the pyrolytic carbon layer is a material having high anisotropy in which crystals of graphite are spread in the plane direction, and the graphite having carbon strongly bonded to each other is spread in the a-axis direction and extends in the c-axis direction of the graphite weakly bonded by van der waals force in the thickness direction. Therefore, in the multi-layered pyrolytic carbon layer, the boundary between one pyrolytic carbon layer and a pyrolytic carbon layer adjacent thereto is weak, and peeling is likely to occur. On the other hand, in the carbon composite member of the present invention, since the pore region having pores is provided at the boundary between one pyrolytic carbon layer and another pyrolytic carbon layer adjacent thereto, the crystal direction of the pyrolytic carbon is disturbed around the pores, the anchor effect can be enhanced, and the interlayer peeling can be prevented.

In addition, the carbon composite member of the present invention for solving the above problems is preferably the following embodiment.

(2) The carbon composite structural member according to (1),

when the pyrolytic carbon layers of 2 or more are sequentially arranged as the 1 st layer, the 2 nd layer, the (n-1) th layer and the (n) th layer from the side close to the graphite substrate,

the 1 st layer has a 1 st opening, the n-th layer has an n-th opening, and

the 1 st opening and the n-th opening are formed at different positions with respect to the graphite base material.

In the carbon composite member according to the preferred embodiment of the present invention, the 1 st opening of the 1 st layer located on the side close to the graphite substrate and the n-th opening of the n-th layer located on the outermost side are located at different positions with respect to the graphite substrate, and therefore, the 1 st opening can be closed, and release of gas, moisture, impurities, and the like from the graphite substrate and adsorption of gas, moisture, impurities, and the like from the outside can be prevented.

(3) The carbon composite member according to (2), wherein the 2 nd layer covers the 1 st opening, and the pore region at the boundary between the 1 st layer and the 2 nd layer in the periphery of the 1 st opening extends obliquely toward the graphite base material.

In the carbon composite member according to the preferred embodiment of the present invention, the 2 nd layer covers the 1 st opening located in the 1 st layer, whereby the effects of preventing the release of gas, moisture, and impurities in the graphite base material and the adsorption from the outside can be improved. Further, since the pore region at the boundary between the 1 st layer and the 2 nd layer in the periphery of the 1 st opening extends obliquely toward the graphite base material, the reinforcing effect of the boundary portion of the 1 st opening, at which stress concentration is likely to occur, can be improved.

(4) The carbon composite structural member according to (2) or (3),

the n-th layer has the pore region at a boundary with the (n-1) -th layer immediately below the n-th layer, and the n-th layer gradually becomes thinner toward the n-th opening.

In the carbon composite member according to the preferred embodiment of the present invention, since the pore region is provided at the boundary between the nth layer and the (n-1) th layer immediately below the nth layer, and the nth layer becomes gradually thinner toward the nth opening, stress concentration can be alleviated, and the effect of reinforcing the boundary portion of the nth opening, which is thinner than other portions, can be improved.

(5) The carbon composite member according to any one of (1) to (4), wherein the pore has a maximum pore diameter of 0.5 to 3.0 μm.

In the carbon composite member according to the preferred embodiment of the present invention, the maximum pore diameter of the pores is 0.5 μm or more, so that pyrolytic carbon components having different orientations formed around the pores can be sufficiently ensured, and the anchor effect can be sufficiently exhibited by the formation of the pores.

Further, by setting the maximum pore diameter of the pores to 3.0 μm or less, stress concentration around the pores can be reduced, and strength reduction due to the presence of the pores can be prevented.

(6) The carbon composite member according to any one of (1) to (5), wherein the pyrolytic carbon layer has a total thickness of 5 to 400 μm.

In the carbon composite member according to the preferred embodiment of the present invention, the total thickness of the pyrolytic carbon layers is 5 μm or more, so that the unevenness of the graphite base material as the porous body can be sufficiently covered, and gas impermeability can be ensured. Further, by setting the total thickness of the pyrolytic carbon layer to 400 μm or less, warping or peeling due to thermal strain of the graphite substrate and the pyrolytic carbon layer can be prevented.

(7) The carbon composite member according to any one of (1) to (6), wherein the graphite substrate is an isotropic graphite material.

In the carbon composite member according to the preferred embodiment of the present invention, since the graphite substrate is an isotropic graphite material and the isotropic graphite has a small anisotropy of characteristics and high uniformity, the difference in thermal expansion coefficient from the pyrolytic carbon layer is small depending on the difference in position and direction, and peeling can be made difficult.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the carbon composite member of the present invention, since the pyrolytic carbon layer is composed of a plurality of layers, the effect of preventing adsorption and desorption of gas, moisture, and impurities in the graphite base material can be enhanced.

On the other hand, the pyrolytic carbon layer is a material having high anisotropy in which crystals of graphite are spread in the plane direction, and the graphite having carbon strongly bonded to each other is spread in the a-axis direction and extends in the c-axis direction of the graphite weakly bonded by van der waals force in the thickness direction. Therefore, in the multi-layered pyrolytic carbon layer, the boundary between one pyrolytic carbon layer and a pyrolytic carbon layer adjacent thereto is weak, and peeling is likely to occur. On the other hand, in the carbon composite member of the present invention, since the pore region having pores is provided at the boundary between one pyrolytic carbon layer and another pyrolytic carbon layer adjacent thereto, the crystal direction of the pyrolytic carbon is disturbed around the pores, the anchor effect can be enhanced, and the interlayer peeling can be prevented.

Drawings

Fig. 1 is an enlarged view of a cross section of a carbon composite member according to embodiment 1 of the present invention.

Fig. 2 is a view showing a manufacturing process of a carbon composite member according to embodiment 1 of the present invention.

Fig. 3 is a sectional view of a carbon composite member according to embodiment 2 of the present invention.

Fig. 4 is an enlarged view of a section a of the carbon composite member according to embodiment 2 of the present invention.

Fig. 5 is an enlarged view of a B-section of the carbon composite member according to embodiment 2 of the present invention.

Fig. 6 is a view showing a manufacturing process of a carbon composite member according to embodiment 2 of the present invention.

Fig. 7 is an enlarged view showing each layer formed in the step (C), (D), and (E) in the manufacturing step shown in fig. 6.

Detailed Description

< embodiment 1>

First, embodiment 1 of the present invention will be explained. Fig. 1 is a view showing a carbon composite member according to embodiment 1 of the present invention, and specifically, is an enlarged view of a cross section in the vicinity of the surface of the carbon composite member.

On the graphite substrate 1, a 1 st layer 2A as one pyrolytic carbon layer and a 2 nd layer 2B as the other pyrolytic carbon layer are laminated. Further, a large number of pores 3 are formed at the boundary between the 1 st layer 2A and the 2 nd layer 2B so as to extend in a layered manner. The region in which the pores 3 are present in a layered state is a pore region 4.

The pyrolytic carbon layers to be the 1 st layer 2A and the 2 nd layer 2B can be formed by a CVD method. In the main part of the pyrolytic carbon layer, the a-axis direction spreads in the plane direction of the graphite substrate 1, and the c-axis direction extends in the perpendicular direction. Therefore, in the case of a member in which 2 or more pyrolytic carbon layers are laminated, peeling is likely to occur from the boundary region where thermal strain or the like occurs. Therefore, in the carbon composite member of the present embodiment, the pore region 4 having the pores 3 is formed at the boundary between the 1 st layer 2A and the 2 nd layer 2B adjacent to each other, and thus the arrangement of the pyrolytic carbon layers is disturbed and peeling is not easily caused.

Such a pore region 4 can be obtained as follows.

Fig. 2 is a view illustrating a manufacturing process of the carbon composite member shown in fig. 1. First, a graphite substrate 1 having a desired shape is prepared. Since the thickness of the pyrolytic carbon layer formed on the graphite substrate 1 increases accordingly, it is preferable to make the thickness smaller according to the size of the carbon composite member or the thickness of the pyrolytic carbon layer formed. In addition, the surface of the graphite substrate 1 may be roughened to improve adhesion to the pyrolytic carbon layer.

Thereafter, the graphite substrate 1 is placed in a CVD furnace, and after being raised to a film formation temperature, a raw material gas is introduced. The film forming temperature is not particularly limited, and may be, for example, 800 to 2000 ℃. The raw material gas for obtaining the pyrolytic carbon layer is not particularly limited as long as it is a hydrocarbon. For example, an alkane such as methane, ethane, propane, or butane, an alkene such as ethylene or propylene, an alkyne such as acetylene, or an aromatic raw material gas such as benzene or toluene can be used.

Thereafter, by maintaining the film formation temperature and introducing the raw material gas for a certain period of time, a pyrolytic carbon layer as the 1 st layer 2A is formed on the surface of the graphite substrate 1. As the carrier gas, an inert gas such as Ar may be used.

Next, at a stage when the 1 st layer 2A as a pyrolytic carbon layer reaches a predetermined thickness, the pore region 4 is formed on the surface of the 1 st layer 2A by a method described in detail below. After the formation of the pore region 4, the pyrolytic carbon is kept constant under CVD conditions for film formation, and another pyrolytic carbon layer as the 2 nd layer 2B is continuously formed on the pyrolytic carbon layer on which the pore region 4 is formed.

When the pyrolytic carbon layer is in a stable film-formed state, the pyrolytic carbon layer is formed in a state of being aligned in a direction such that the a-axis direction extends in the horizontal direction (the left-right direction in the figure) with respect to the graphite substrate 1 and the c-axis direction extends in the vertical direction (the up-down direction in the figure) with respect to the graphite substrate 1; in an unstable film formation state, the raw material gas is pyrolyzed above the graphite substrate 1 to form particles and accumulate the particles on the graphite substrate 1, thereby disturbing the alignment of the pyrolytic carbon layer. Such alignment disorder causes a decrease in the function of the pyrolytic carbon layer, such as deterioration in airtightness, when the pyrolytic carbon layer is formed in a main portion of the pyrolytic carbon layer.

However, in the carbon composite member of the present embodiment, the pore region 4 is generated at the boundary between the 1 st layer 2A and the 2 nd layer 2B, and therefore, it does not cause deterioration in performance of the carbon composite member, but acts to enhance the bonding force between the 1 st layer 2A and the 2 nd layer 2B, which are 2 or more pyrolytic carbon layers, and has an effect that peeling is not easily generated.

The pore region 4 can be formed at any time of the completion of the film formation of the 1 st layer 2A or the start of the film formation of the 2 nd layer 2B. For example, when the formation of the 2 nd layer 2B is started, the formation of the pyrolytic carbon layer as the 2 nd layer 2B is performed under stable conditions after particles are generated on the surface of the 1 st layer 2A under a temporary unstable condition such as a rise in the partial pressure of gas or a rise in the temperature at the start. In the case of formation of the 1 st layer 2A at the time of completion of film formation, the gas partial pressure or temperature increase at the time of completion is temporarily unstable, and after the particles are generated, the formation of the pyrolytic carbon layer as the 2 nd layer 2B is performed under stable conditions. Since particles are scattered and accumulated on the surface of the 1 st layer 2A, pores 3 are formed around the particles when the pyrolytic carbon layer as the 2 nd layer 2B is formed thereon. The pores 3 are spread in a layer shape at the boundary between the 1 st layer 2A and the 2 nd layer 2B to form a pore region 4.

As an example of the conditions for forming and depositing the particles of pyrolytic carbon, the pressure in a CVD furnace is set to 10 to 10000Pa and the temperature is set to 800 to 2000 ℃.

Further, in order to deposit more particles of pyrolytic carbon on the surface of the 1 st layer 2A and to form more pores 3, the upper space of the pyrolytic carbon layer may be enlarged in the CVD furnace. When the upper space is enlarged, the amount of the produced pyrolytic carbon particles is increased, and more pyrolytic carbon particles can be deposited on the surface of the 1 st layer 2A.

In the above description, the case where the pyrolytic carbon layer has a 2-layer structure of the 1 st layer 2A and the 2 nd layer 2B is shown as an example, but the pyrolytic carbon layer of the present embodiment may be a multilayer of 3 or more. In this case, the formation of the pore region 4 may be performed at the start of film formation of each layer or at the end of film formation. In addition, when the pyrolytic carbon layer is 3 or more, the effect of the present invention can be exerted if the above-mentioned pore region 4 is provided at the boundary between at least 1 group of adjacent pyrolytic carbon layers, but in order to sufficiently exert the effect of preventing interlayer peeling, it is preferable that the entire boundary between 1 group of adjacent pyrolytic carbon layers has the pore region 4.

The pyrolytic carbon layer may be formed on both surfaces of the graphite substrate 1, and after the pyrolytic carbon layer is formed on one surface of the graphite substrate 1, the other surface of the graphite substrate 1 may be turned upside down to form a top surface. Alternatively, the pyrolytic carbon layer may be formed so as to cover the entire surface of the graphite substrate 1. The pore region 4 may be formed at the start of film formation or at the end of film formation of each layer in the same manner.

The maximum pore diameter of the pores 3 is preferably 0.5 to 3.0 μm. By setting the maximum pore diameter of the pores 3 to 0.5 μm or more, pyrolytic carbon components having different orientations formed around the pores 3 can be sufficiently ensured, and the anchor effect can be sufficiently exerted by the formation of the pores 3. Further, by setting the maximum pore diameter of the pores 3 to 3.0 μm or less, the concentration of stress around the pores 3 can be reduced, and the strength can be prevented from being lowered by the presence of the pores 3. The maximum pore diameter of the pores 3 is more preferably 1 to 2 μm.

If the pore region 4 is too thick, peeling easily occurs from the pores 3 as a starting point; if the pore region 4 is too thin, the effect of disturbing the orientation of the pyrolytic carbon is reduced, and the effect of enhancing the bonding force between the upper and lower pyrolytic carbon layers is not obtained. Therefore, the thickness of the pore region 4 is preferably 0.5 to 20 μm, more preferably 1 to 5 μm.

The total thickness of the pyrolytic carbon layer is preferably 5 to 400 μm. By setting the total thickness of the pyrolytic carbon layers to 5 μm or more, the unevenness of the graphite substrate 1 as the porous body can be sufficiently covered, and gas impermeability can be ensured. Further, by setting the total thickness of the pyrolytic carbon layer to 400 μm or less, warping and peeling due to thermal strain of the graphite substrate 1 and the pyrolytic carbon layer can be prevented. The pyrolytic carbon layer preferably has a total thickness of 10 to 200 μm.

Here, the thickness of the pyrolytic carbon layer is a thickness other than the pore region 4, for example, the thickness of the 1 st layer 2A formed on the graphite substrate 1 is the thickness of the 1 st layer 2A, and the thickness of the pyrolytic carbon layer deposited by changing the film forming conditions for producing particles is not included. The thickness of the 2 nd layer 2B is the thickness of the pyrolytic carbon layer when the film is formed after the particles are produced.

The graphite material forming the graphite substrate 1 is preferably an isotropic graphite material. In isotropic graphite, since anisotropy of properties is small and uniformity is high, a difference in thermal expansion coefficient from a pyrolytic carbon layer is small depending on a difference in position and direction, and exfoliation can be made difficult.

< embodiment 2>

Next, embodiment 2 of the present invention will be explained. Fig. 3 is a sectional view of a carbon composite member according to embodiment 2 of the present invention.

The carbon composite member shown in fig. 3, that is, the carbon composite member in which 2 or more pyrolytic carbon layers are formed on the entire surface of the graphite substrate 1 can be produced by a production method using a specific support tool shown in fig. 1 of japanese patent application laid-open No. 2016-169422 (details of the production method will be described later). In this case, the 1 st opening 10 and the 2 nd opening 11 are formed in a part of the pyrolytic carbon layer.

As shown in fig. 3, in the carbon composite member of the present embodiment, the graphite substrate 1 is covered with the 1 st layer 2A and the 2 nd layer 2B, and the 1 st layer 2A has the 1 st opening 10 (at 2 in fig. 3) on one surface (upper surface in the figure) of the graphite substrate 1, and the 2 nd layer 2B covers the 1 st opening 10. Therefore, the 2 nd layer 2B ensures airtightness from the 1 st opening 10 to the graphite substrate 1. On the other hand, the graphite substrate 1 has no 1 st opening 10 on the other surface (lower surface in the figure), the entire surface thereof is covered with the 1 st layer 2A, and the 2 nd layer 2B has a 2 nd opening 11 (at 2 in fig. 3). Therefore, the 1 st layer 2A ensures airtightness from the 2 nd openings 11 to the graphite substrate 1.

That is, since the 1 st opening 10 of the 1 st layer 2A located on the side close to the graphite substrate and the 2 nd opening 11 of the 2 nd layer 2B located on the outer side are located at different positions with respect to the graphite substrate 1 (positions where the 1 st opening 10 and the 2 nd opening 11 do not overlap in the direction in which the pyrolytic carbon layers are laminated), the 1 st opening 10 can be closed, and release of gas, moisture, impurities, and the like from the graphite substrate 1 and adsorption of gas, moisture, impurities, and the like from the outside can be prevented. The 1 st opening 10 and the 2 nd opening 11 may be formed in 1 st layer 2A and 2 nd layer 2B, respectively, or may be formed in a plurality of portions.

In fig. 3, the case of 2 layers, i.e., the 1 st layer 2A and the 2 nd layer 2B, has been described as the pyrolytic carbon layer having 2 or more layers, but for example, when the pyrolytic carbon layer having 2 or more layers is the 1 st layer, the 2 nd layer, · · · n-1 st layer, and the n-th layer in this order from the side close to the graphite substrate 1, the 1 st layer has the 1 st opening, the n-th layer has the n-th opening, and the 1 st opening and the n-th opening are formed at different positions with respect to the graphite substrate 1 (positions where the 1 st opening and the n-th opening do not overlap in the stacking direction of the pyrolytic carbon layer), the same effects as described above can be exhibited. N is an integer of 2 or more.

Fig. 4 is an enlarged view of the section a of fig. 3, showing in detail the periphery of the 1 st opening 10 (region C in the figure) formed in the 1 st layer 2A.

As shown in fig. 4, the 2 nd layer 2B covers the 1 st opening 10, and the pore region 4 at the boundary between the 1 st layer 2A and the 2 nd layer 2B in the 1 st opening periphery (C region) extends obliquely toward the graphite substrate 1. That is, since the 2 nd layer 2B covers the 1 st opening 10 located in the 1 st layer 2A, the effect of preventing the release of gas, moisture, and impurities in the graphite base material 1 and the adsorption from the outside can be improved. Further, since the pore region 4 at the boundary between the 1 st layer 2A and the 2 nd layer 2B in the periphery (C region) of the 1 st opening extends obliquely toward the graphite substrate 1, the reinforcing effect of the boundary portion of the 1 st opening 10, which is likely to cause stress concentration, can be improved.

Fig. 5 is an enlarged view of the section B of fig. 3, showing in detail the periphery (region D) of the 2 nd opening 11 formed in the 2 nd layer 2B.

As shown in fig. 5, the 1 st layer 2A has no opening, and the 2 nd layer 2B is formed by stacking on the upper surface (lower side in the figure) of the 1 st layer 2A, and has the 2 nd opening 11 in the 2 nd layer 2B. Further, since the pore region 4 is provided at the boundary between the 2 nd layer 2B and the 1 st layer 2A immediately below the 2 nd layer 2B, the 2 nd layer 2B becomes gradually thinner toward the 2 nd opening 11 as shown by the region D in the drawing, stress concentration can be alleviated, and the effect of reinforcing the boundary portion of the 2 nd opening having a smaller thickness can be improved as compared with other portions.

In fig. 5, the case of 2 layers, i.e., the 1 st layer 2A and the 2 nd layer 2B, has been described as the pyrolytic carbon layer having 2 or more layers, but as in the case described in fig. 3, the same effects as described above can be exerted as long as the pore region 4 is provided at the boundary between the n-th layer and the n-1 th layer immediately below the n-th layer, and the n-th layer is gradually thinned toward the n-th opening. N is an integer of 2 or more.

Next, a method for producing a carbon composite member according to embodiment 2 of the present invention will be described in detail. In the production of such a carbon composite member, the steps shown in fig. 6, for example, may be performed.

Fig. 6 (a) shows the graphite substrate 1, (B) shows the step of forming the 1 st layer 2A, (C) shows the step of forming the pore region 4 on the 1 st surface 1a side of the graphite substrate 1, (D) shows the step of forming the pore region 4 on the 2 nd surface 1B side (i.e., on the side where the 1 st opening 10 is formed) of the graphite substrate 1, and (E) shows the step of forming the 2 nd layer 2B. As shown in fig. a, one surface (upper surface in the figure) of the graphite substrate 1 is referred to as a 1 st surface 1a, and the other surface (lower surface in the figure) is referred to as a 2 nd surface 1 b. Fig. 7 is an enlarged view of the respective layers formed in the step (C), the step (D), and the step (E) of fig. 6.

First, as shown in step (B), the graphite substrate 1 is placed on the support tool 20. The support tool 20 is mounted on a substrate holder (not shown) of the CVD apparatus. The supporting device 20 has, for example, a cylindrical supporting device body 21 and a supporting portion 22 protruding from a central portion of the supporting device body 21, and is formed integrally. For example, the supporting device body 21 and the supporting portion 22 may be processed to obtain the supporting device body 21 and the supporting portion 22, and the supporting device body 21 and the supporting portion 22 may be bonded to each other with an adhesive or the like to integrate them.

The support portion 22 has a truncated cone shape as a whole, and has a shape having an inclined surface whose diameter is gradually increased from the top surface 23 toward the support device body 21 in a cross section along the axis. The top surface 23 may have a shape (conical shape) with a sharp tip, in addition to the illustrated flat surface. The 2 nd surface 1b of the graphite substrate 1 is in contact with and supported by the support portion 22.

In this state, a stable CVD method is performed to form a pyrolytic carbon layer. As a result, as shown in the figure, the 1 st layer 2A is formed so as to cover the graphite base material 1 except for the periphery of the support portion 22 of the support jig 20. At this time, the 1 st opening 10 is formed in the 1 st layer 2A in a shape along the outer shape of the support portion 22.

Next, as shown in step (C), unstable CVD is performed to form a pore region 4 on the entire surface of the 1 st surface 1a of the graphite substrate 1 of the 1 st layer 2A. It is considered that the number of the pore regions 4 is not small on the 2 nd surface 1b side of the graphite substrate 1, but is smaller than on the 1 st surface 1a side of the graphite substrate 1.

Next, as shown in the step (D), the front and back surfaces of the graphite substrate 1 are turned over (turned upside down), and the 1 st surface 1a is placed on the support 20. Accordingly, the 1 st opening 10 of the 1 st layer 2A faces upward in the drawing. After which unstable CVD is performed again. The pore region 4 is formed on the entire surface of the graphite substrate 1 on the 2 nd surface 1b side (i.e., on the side where the 1 st opening 10 is formed). At this time, since particles of pyrolytic carbon are also deposited on the 1 st opening 10, the pore region 4 is also formed on the 1 st opening 10 (see fig. 4).

Subsequently, as shown in the step (E), stable CVD is performed to form the 2 nd layer 2B. Through the above steps, the 1 st opening 10 is closed by the 2 nd layer 2B to be in the state shown in fig. 4, and the 2 nd opening 11 is also formed with the pore region 4 to be in the state shown in fig. 5. That is, the carbon composite member in which the 1 st opening 10 is covered with the 2 nd layer 2B, the pore region 4 at the boundary between the 1 st layer 2A and the 2 nd layer 2B in the periphery of the 1 st opening (C region) extends obliquely toward the graphite substrate 1, and the 2 nd layer 2B gradually becomes thinner toward the 2 nd opening 11 can be manufactured by the above manufacturing method.

As described above, since the 1 st layer 2A and the 2 nd layer 2B are formed using, for example, the columnar support tool body 21 and the truncated cone-shaped support portion 22 protruding from the central portion of the support tool body 21 as the support tool 20, the pyrolytic carbon layers gradually thinner toward the openings (the 1 st opening 10 and the 2 nd opening 11) of each layer can be formed.

The present invention has been described above with reference to embodiments 1 and 2, but the present invention is not limited to these embodiments, and modifications, improvements, changes, and the like can be appropriately made.

Industrial applicability

In the carbon composite member of the present invention, the graphite substrate is coated with the plurality of pyrolytic carbon layers, whereby the carbon composite member exhibits higher performance as a whole, and further suppresses separation between the pyrolytic carbon layers, and is excellent in durability. And thus is effective in many fields such as semiconductor fabrication, chemical industry, machinery, atomic energy, and the like.

Description of the symbols

1 graphite substrate

2A layer 1 (a pyrolytic carbon layer)

2B layer 2 (other pyrolytic carbon layer)

3 air holes

4 pore area

10 st opening part

11 nd 2 nd opening part

20 support device

21 supporting device body

22 support part

23 top surface of