JPH10330185A - Crucible for pulling single crystal and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the molding time of a C/C (carbon fiber reinforced carbon composite) crucible as well as to obtain a C/C crucible easy to bulk-produce, and to offer a method for producing it. SOLUTION: This crucible for pulling a single crystal is made of a carbon fiber reinforced carbon composite (i.e., C/C) material, and comprises a cylindrical body 2 and a disk-like bottom part 5, where both components are formed separately from each other and can be assembled by inserting the bottom part 5 into the body 2 and then fixing at the skirt part of the bottom part 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single crystal pulling crucible used for a single crystal pulling apparatus and the like by the Czochralski method (hereinafter referred to as "CZ method") and a method for producing the same. The present invention relates to a single crystal pulling crucible made of a carbon composite material (hereinafter referred to as “C / C material”) and a method for producing the same.

[0002]

2. Description of the Related Art For example, in the production of a semiconductor single crystal by the CZ method, a quartz crucible for melting a semiconductor material such as silicon therein and a crucible for accommodating and supporting the quartz crucible have conventionally been used. Is used. Usually, graphite crucibles for supporting quartz crucibles are used (hereinafter, referred to as "graphite crucibles"). When a semiconductor single crystal is manufactured using a graphite crucible that contains the quartz crucible inside, the quartz crucible is softened by the heat of melting of the semiconductor material during use, and the outer wall surface adheres to the inner surface of the graphite crucible. It will be in the state of having done. On the other hand, graphite crucibles expand due to heat. Therefore, when the semiconductor single crystal manufacturing process is completed, and the quartz crucible and the graphite crucible are cooled, the graphite crucible having a larger coefficient of thermal expansion than the quartz crucible shrinks significantly compared to the quartz crucible, Cracks may occur.

[0003] Therefore, it has been proposed to form a single crystal pulling crucible with a C / C material that does not cause cracks due to the difference in the coefficient of thermal expansion. There is no risk of accompanying cracks because the coefficient of thermal expansion is close to that of SiO ₂ , which is a constituent material of the quartz crucible, and the mechanical strength is higher than that of the quartz crucible. Such a single crystal pulling crucible made of a C / C material is formed by various methods such as a filament winding method (hereinafter referred to as "FW method") in which carbon fibers are wound around a forming die and formed.

[0004]

However, a method for producing a single crystal pulling crucible (hereinafter referred to as "C / C crucible") made of a C / C material using the FW method is based on a method in which carbon fiber is made of resin or the like. Is a method in which the carbon fiber is wound around a mold while being impregnated with the matrix material to form a predetermined shape, so that a C / C crucible having excellent mechanical strength can be formed, but in particular, the cross section is U-shaped. However, there is a problem that it is difficult to form the curved portion of the single crystal pulling crucible having the above structure, and it takes a long time to form.

Accordingly, in the present invention, a C / C crucible which can be easily mass-produced while shortening the molding time of the C / C crucible is provided.
An object of the present invention is to provide a crucible and a method for manufacturing the same.

[0006]

According to the first aspect of the present invention,
A single crystal pulling crucible formed of carbon fiber reinforced carbon composite material, comprising a cylindrical body and a disc-shaped bottom, wherein the body and the bottom are formed separately, and the disc-shaped Is inserted into the cylindrical body and fixed at the end so as to be assembled. With this structure, the shape of the body becomes a simple cylindrical shape, and the shape of the bottom becomes a simple disk shape.
By separately forming the body and the bottom, the C / C crucible can be easily formed. Further, the body and the bottom can be formed simultaneously. By these, C /
The molding period of the C crucible is shortened, and the C / C crucible can be easily mass-produced. In addition, since the body and the bottom are formed separately, thermal stress can easily escape, and a C / C crucible resistant to thermal stress can be formed.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, an inner side surface of the cylindrical body is formed by:
A cloth made of carbon fiber entangled with a matrix material is wound around a cylindrical mold, and the cloth made of carbon fiber and a matrix material are combined to form a carbon fiber reinforced carbon composite material. The outer side of the torso is
A carbon fiber entangled with a matrix material is wound around the cylindrical molding die, and is formed of a carbon fiber reinforced carbon composite material in which the carbon fiber and the matrix material are combined. Since the body is cylindrical, FW
In the case of molding by an apparatus, a cylindrical mold having a simple shape can be used, and a cloth made of carbon fibers and winding of carbon fibers can be easily performed. Accordingly, the molding period of the body can be shortened, so that the molding period of the entire C / C crucible can be shortened, and the C / C crucible can be easily mass-produced. Also, even if a quartz crucible is inserted into the inside of the body, the inner side surface of the body is formed including a carbon fiber reinforced carbon composite material obtained by combining a cloth made of carbon fiber and a matrix material. In addition, the reaction with SiO ₂ contained in the quartz crucible can be suppressed, and damage to the C / C crucible can be suppressed. In addition, the outer side of the torso
Since it is formed by winding carbon fibers, a C / C crucible having excellent mechanical strength against radial stress can be formed.

According to a third aspect of the present invention, there is provided a method of manufacturing a single crystal pulling crucible formed of a carbon fiber reinforced carbon composite material, wherein a step of forming a cylindrical body is provided. In parallel with the step of forming, a step of forming a disc-shaped bottom, and an assembling step of inserting the disc-shaped bottom into the cylindrical body and fixing it at an end of the cylindrical body. It is characterized by including. By forming the shape of the body portion into a simple cylindrical shape, the forming process of the body portion can be simplified. In addition, by forming the shape of the bottom portion into a simple disk shape, the process of forming the bottom portion can be simplified. Further, by separately performing the step of forming the body and the step of forming the bottom, the body and the bottom can be formed at the same time. Therefore, the molding period of the C / C crucible can be shortened, and the C / C crucible can be shortened. C crucibles can be easily mass-produced.

According to a fourth aspect of the present invention, in addition to the configuration of the third aspect of the invention, the step of forming the cylindrical body portion includes forming a cylindrical inner side surface of the body portion. Winding the matrix material on the cloth made of carbon fiber in the forming die, and winding the matrix material on the cylindrical forming die in order to form the outer side surface of the body, And a step of winding. Since the molding die is cylindrical, the process of winding the carbon fiber cloth and the carbon fiber can be easily performed. Accordingly, the molding period of the body can be shortened, so that the molding period of the entire C / C crucible can be shortened, and the C / C crucible can be easily mass-produced. Even if a quartz crucible is inserted inside the body, the inner side surface of the body is formed including a step of winding the matrix material around a cloth made of carbon fiber while winding the matrix material.
By suppressing the reaction with SiO ₂ contained in the quartz crucible, it is possible to form a C / C crucible in which the inside of the body is hardly damaged. In addition, since the outer side surface of the trunk portion is formed including the step of winding the carbon fiber, a C / C crucible having excellent mechanical strength against radial stress can be formed.

[0010]

1 and 2 show an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of a C / C crucible. FIG. 2 is an enlarged partial cross-sectional view of FIG. 1 and illustrates a fixing structure between a trunk and a bottom.

In FIG. 1, reference numeral 1 denotes a C / C crucible,
Reference numeral 2 denotes a body portion, reference numeral 5 denotes a bottom portion, reference numeral 6 denotes a fixed portion,
Reference numeral 16 indicates a support. The C / C crucible 1 is formed from a body 2, a bottom 5, and a fixing part 6. The C / C crucible 1 is formed in a bottomed cylindrical shape, and a space for accommodating a quartz crucible (not shown) is formed therein. The C / C crucible 1 is provided on a support 16.

The bottom portion 5 is formed in a disk shape, and serves as a pedestal surface of the quartz crucible (hereinafter, referred to as a “pedestal surface”) 5.
a and a notch 5e. The disk-shaped bottom portion 5 is formed to have a smaller diameter than the inner diameter of the body portion 2.
The length in the axial direction is shorter than the length in the axial direction of the body 2, and is formed so as to be inserted into the body 2. The bottom 5 has a depression formed in the upper surface thereof on the paper surface, and supports a quartz crucible having a U-shaped cross section. Further, the bottom part 5 is formed horizontally with respect to the upper surface of the support base 16 so that the lower surface 5 k is provided on the support base 16.

The pedestal surface 5a is formed on the bottom 5 so as to be curved.
Is formed along the lower surface of the quartz crucible. The pedestal surface 5a only needs to be formed so as to support the quartz crucible, and is not limited to a curved surface, and may be formed on a horizontal flat surface.

The bottom 5 is formed to have a predetermined thickness 5b below the pedestal surface 5a. The predetermined thickness 5b is a length from the lowest point 5c of the pedestal surface 5a to the vertical lower end 5d of the bottom 5. The predetermined thickness 5b is formed to have a thickness that can withstand expansion and contraction due to heat of the quartz crucible from the viewpoint of mechanical strength.

The notch 5e is provided at each position where the circumference of the bottom 5 is divided into six equal parts, and has a surface 5f parallel to the lower surface 5k of the bottom 5 and a surface 5g parallel to the side surface of the bottom 5. , Face 5f
2 and a surface 5l and a surface 5m which intersect perpendicularly with the surface 5g (FIG. 2).
(See (b)). As described above, the notch 5 e is provided by cutting the side surface of the bottom 5, and is fitted to the fixing portion 6 when the bottom 5 is inserted into the body 2.

The body 2 is composed of an inner body 3 and an outer body 4. As shown in FIG. 1, the inner trunk portion 3 is formed in a cylindrical shape, and has a fixing portion 6 to be fitted to the bottom portion 5. The inner trunk 3 has an inner diameter larger than the outer diameter of the quartz crucible so that the quartz crucible can be inserted into the inner trunk 3. The axial end face 3 b of the inner trunk 3 in the axial direction is formed horizontally with respect to the upper surface of the support base 16 so as to be stably fixed on the support base 16.

The inner body 3 is formed by a manufacturing method described later.
It is formed by a layer of C / C material including cloth made of carbon fiber. Since the cloth made of carbon fibers is made by weaving carbon fibers, gaps between the bundles of carbon fibers are reduced. By using a cloth made of carbon fiber as described above, even if a quartz crucible is
Reaction with SiO ₂ contained in the quartz crucible can be suppressed.

The outer body 4 is formed in a cylindrical shape.
The inner body 3 is formed to have the same length as both ends. The outer trunk 4 has an inner diameter larger than the outer diameter of the inner trunk 3, and is formed so that the inner trunk 3 can be inserted into the outer trunk 4. This outer trunk 4
Is formed of a C / C material containing carbon fibers wound in the radial direction by a manufacturing method described later. For this reason, the quartz crucible has excellent mechanical strength against radial stress due to thermal expansion.

The fixing part 6 is formed of a C / C material.
The fixing portion 6 is provided so as to protrude inward from the inner side surface 3 a of the inner trunk portion 3, and fits with the cutout portion 5 e of the bottom portion 5. The lower surface of the fixing portion 6 coincides with the shaft end surface 3b at the lower end of the inner trunk portion 3, and the lower ends of the fixing portion 6 and the inner trunk portion 3 form a flat surface. Further, the fixing portion 6 and the inner trunk portion 3 are connected to each other in FIG.
As shown in (a), two bolts 7 are passed through a position where the inner side surface 3a of the inner trunk portion 3 and the side surface of the fixing portion 6 overlap. Further, as shown in FIG. 2B, the fixing portion 6
It is provided at each position which divides the circumference of the inner trunk 3 into six equal parts. The bolt 7 is made of a C / C material in consideration of thermal expansion, but may be made of graphite.

Next, the assembly structure of the inner trunk 3, the outer trunk 4, and the bottom 5 will be described with reference to FIG. The inner trunk 3 is inserted into the outer trunk 4 to form a C / C crucible having a double structure. Note that the inner trunk 3 may be bonded to the inside of the outer trunk 4. The bottom 5 is inserted into the inner body 3 so that when the quartz crucible is inserted into the inside of the inner body 3, the pedestal surface 5 a of the bottom 5 becomes a pedestal for the quartz crucible. Are fixed to the inside of the inner trunk 3 by fitting a notch 5e provided by notching the side surface of the inner trunk 3 with a fixing portion 6 protruding inside the inner side surface 3a of the inner trunk 3. At this time, when the bottom 5 is fixed at the end of the inner trunk 3 (a position where a flat plane is formed by the shaft end face 3b of the inner trunk 3, the lower surface 5k of the bottom 5, and the lower surface of the fixing portion 6), The stability of the entire C / C crucible 1 is improved.

The fixing structure between the inner trunk 3 and the bottom 5 is as follows.
The present invention is not limited to the above-described structure, and can be fixed without using the bolts 7 by processing the lower ends of the inner trunk portion 3 and the bottom portion 5. In this case, the inner trunk 3 and the outer trunk 4 may be formed integrally instead of being separate members. When the inner trunk portion 3 and the outer trunk portion 4 are integrated, the inner side surface of the trunk portion 2 is formed by wrapping a cloth made of carbon fibers, and the outer side surface of the trunk portion 2 is formed by wrapping carbon fibers. Is done.

FIG. 3 is a view for explaining another fixing structure of the body 2 and the bottom 5. In FIG. 3A, reference numeral 2 denotes a trunk, reference numeral 2a denotes a shoulder, and reference numeral 5n denotes an annular cutout.
The shoulder 2 a is formed by reducing the inner diameter of the body 2, and includes a surface 2 c parallel to the inner surface 2 e of the body 2 and a surface 2 b perpendicular to the inner surface 2 e of the body 2. Have been. The notch 5n is provided at the lower end of the side surface of the bottom 5. The notch 5n is formed by reducing the diameter of the bottom 5 and includes a surface 5o parallel to the lower surface 5k of the bottom 5 and a surface 5p parallel to the side surface of the bottom 5. By forming the notch 5n on the side surface of the bottom portion 5, the shoulder 2a is fitted into the notch 5n so that the surface 5o of the notch 5n coincides with the surface 2b of the shoulder 2a. The bottom 5 can be fixed.

In FIG. 3B, reference numeral 5h denotes a shoulder of the bottom 5. The shoulder 5h is provided at the lower end of the side surface of the bottom 5. The shoulder 5h is formed so as to increase in diameter until the diameter of the lower portion of the bottom 5 becomes substantially the same as the outer diameter of the body 2, and a surface 5j that is horizontal to the lower surface 5k of the bottom 5; The bottom 5 has a surface 5i parallel to the side surface 5q.
Forming the shoulder 5h on the bottom 5 allows the lower end 2d of the body 2 to coincide with the surface 5j of the bottom 5 so that the body 2 and the bottom 5 can be fitted and fixed.

As shown in FIG. 3C, for example, the bottom 5
After the body 5 and the bottom 5 are inserted into the body 2 without processing the end, the inside diameter of the body 2 and the diameter of the bottom 5 are substantially the same size, and the side of the bottom 5 is The body 2 is formed so as to be fitted by the surface frictional force with the inner side surface 2 e and the tightening force of the body 2.

In any of the above cases, it is desirable to fix the bottom 5 so that the entire lower surface of the C / C crucible 1 is flat.

As described above, the body 2 and the bottom 5 are separately molded so that the body 2 has a simple cylindrical shape and the bottom 5 has a simple disk shape. / C
The crucible 1 can be easily formed.

Further, since the body portion 2 and the bottom portion 5 are separate members, thermal stress is easily released, so that the structure is strong against thermal stress. Further, since the body 2 can be removed from the bottom 5, even if the body 2 is damaged,
By replacing only the bottom part 5, the bottom part 5 can be used continuously. Furthermore, residues such as silicon remaining on the bottom 5 after the single crystal is pulled can be easily removed.

The bottom 5 is inserted into the body 2 and the bottom 5
Is fixed to the end of the body 2 on the side of
There is no substantial connecting portion connecting the body and the body 2 on the pedestal surface 5a or the like to which the stress due to the thermal expansion of the quartz crucible is directly applied, so that the structure is strong against the stress due to the thermal expansion of the quartz crucible.

A method suitable for manufacturing the C / C crucible 1 according to the present invention will be described with reference to FIGS. FIG.
FIG. 3 is a view for explaining a molding die. FIG. 5 is a diagram illustrating a molding die for molding the bottom. FIG. 6 is a diagram for explaining a process of assembling the body and the bottom.

According to the method of manufacturing the C / C crucible 1 of the present invention, a step of forming the body 2, a step of forming the bottom 5 performed in parallel with the step of forming the body 2, 2 and a step of assembling the bottom 5. This C / C
In the method for manufacturing the crucible 1, the step of forming the body 2 and the step of forming the bottom 5 can be performed in parallel.
The production period of the C / C crucible 1 can be shortened comprehensively, which is suitable for mass production. Hereinafter, each step will be described in detail.

A method of manufacturing the body 2 will be described with reference to FIG. FIG. 4 is a diagram illustrating a molding die. In FIG. 4, reference numerals 8 and 10 denote molding dies, and reference numeral 9 denotes a rotating shaft.

The first molding die 8 and the second molding die 10 are shown in FIG.
As shown in (a) and (b), it is formed in a hollow cylindrical shape. The rotating shaft 9 penetrates in the axial direction of the first forming die 8 and the second forming die 10. Thereby, the first molding die 8 and the second molding die 10 are supported by the rotating shaft 9,
It is adapted to be rotated by a rotating shaft 9. And
Filament winding device (hereinafter "FW device")
That. ) And the like rotate the rotation shaft 9,
The molding die 8 and the second molding die 10 are rotated to wind the carbon fiber and the cloth made of the carbon fiber.

As described above, unlike the conventional molds for integrally molding a C / C crucible, the first and second molds 8 and 10 having a hollow columnar shape do not include a hemispherical portion.
Even in the case of the FW method, the winding of the carbon fiber or the cloth made of the carbon fiber can be easily performed, and the molding period is shortened. Also, the first
By forming both ends of the molding die 8 and the second molding die 10 to be long, a plurality of body parts 2 can be molded at one time.

The process of forming the body 2 using the first and second molding dies 8 and 10 will be described. First, the first molding die 8 is wound around a carbon fiber entangled with a matrix material by the FW method (molding of the outer body portion 4). At the same time, a cloth made of carbon fiber entangled with a matrix material is wound around the second mold 10 (forming the inner body 3). Next, pressure is applied to the molded body of the inner body 3 and the molded body of the outer body 4 to harden them, and then carbonized by firing. Also, the fixing portion 6 is formed in parallel with the above-described forming process of the body portion 2.
Is molded.

As described above, the inner trunk 3, the outer trunk 4, and the fixing part 6 are formed in parallel, and after the molding, the inner trunk 3 and the fixing part 6 are fixed by bolts 7. And the inner trunk 3
Is inserted into the outer body 4 to form the body 2. In addition, the step of inserting the inner body 3 into the outer body 4 is performed in the following manner.
It may be carried out after the step of fixing the and the fixing portion 6.

As the matrix material, any material which is carbonized by heat treatment, for example, a thermosetting resin such as a phenol resin, a furan resin, a furfuryl alcohol resin, or a pitch-based material may be used.

In the case where densification is to be achieved, for example, CV
Thermal decomposition by I (Chemical Vapor Infiltration) method
Coating such as infiltration or deposition of carbon is performed by S
iO _TwoFrom the viewpoint of suppressing the reaction with aluminum and the viewpoint of mechanical strength?
Are preferred. In addition, CVD (Chemical Vapor Depositio)
n) method to infiltrate or deposit pyrolytic carbon to cover
May be applied.

The step of forming the bottom 5 will be described with reference to FIG. In FIG. 5, reference numeral 5 denotes a bottom, reference numeral 12 denotes a third molding die, reference numeral 13 denotes an upper die, reference numeral 14 denotes a lower die,
Reference numeral 15 indicates a spherical surface. The third mold 12 has an upper mold 13 and a lower mold 14, and is configured to mold the bottom 5 by applying pressure to the upper mold 13 and the lower mold 14. The lower mold 14 has a spherical surface 15 formed at the center thereof so that the pedestal surface 5a of the bottom 5 can be formed. In addition, the upper die 13 has a columnar space partially formed with a concave portion for forming the lower surface 5k and the side surface of the bottom portion 5 and the cutout portion 5e. Note that the lower mold 14 is only required to form the pedestal surface 5a along the lower surface of the quartz crucible, and is not limited to the one having the spherical surface 15 at the center thereof.

The step of forming the bottom 5 using the third mold 12 will be described. A resin is applied to a cloth made of carbon fiber, and the prepreg is cut into strips.
The material for forming the bottom 5 is not limited to the cloth made of carbon fibers, and short carbon fibers may be used.

Next, a strip-shaped prepreg is put on the spherical surface 15 of the lower mold 14 and laminated so as to have a predetermined thickness. Then, the upper mold 13 is pressed against the lower mold 14 and hot-pressed to obtain a molded body of the bottom 5. Next, firing is performed,
The compact at the bottom 5 is carbonized. Then, the compact is again impregnated with the matrix material and fired to carbonize the compact. Next, after graphitization, the molded body is machined.

The process of forming the body 2 and the bottom 5 is as described above, but was specifically performed under the following conditions.

In the step of molding the body 2, the first molding die 8
A mold made of metal having a large coefficient of thermal expansion from the viewpoint of ease of removal and having dimensions of an outer diameter φ600 mm, an inner diameter φ580 mm, and both ends 1500 mm was used. In addition, the second mold 10 is made of metal like the first mold 8, and the size thereof is
A mold having an outer diameter of 580 mm, an inner diameter of 560 mm, and a distance between both ends of 1500 mm was used. In the case of cloth made of carbon fiber, 3
K plain weave cloth was used, and 12K carbon fiber was used as the carbon fiber. The curing process is performed at 110 ° C for two and a half hours,
Further, it was performed at 160 ° C. for 5 hours. Next, primary firing was performed at 800 ° C. for 72 hours. After impregnation with a pitch-based material, firing was performed again at 1000 ° C. In addition, the baking process was repeated twice. The graphitization was performed in a halogen gas at 2000 ° C.

In the step of forming the bottom 5, a prepreg obtained by applying a phenol resin to a spun yarn (made of spun carbon fiber) plain woven cloth was used. The third mold 12 has a bottom diameter A of φ580 mm and a height H of t300.
A mold having a predetermined thickness of 40% Vf (fiber volume) in mm was used. The firing is performed at 1000 ° C.
After impregnation with the pitch-based material, firing was performed again at 1000 ° C. In addition, the baking process was repeated twice. Graphitization was performed at 2000 ° C.

The process of assembling the body 2 and the bottom 5 is shown in FIG.
This will be described with reference to FIG. When the quartz crucible is inserted into the body 2, the bottom 5 is inserted into the body 2 so that the pedestal surface 5 a of the bottom 5 serves as a base for the quartz crucible. Then, the notch 5e of the bottom portion 5 is fitted to the fixing portion 6 of the body portion 2 to fix the bottom portion 5 and the body portion 2 (see FIG. 2A).

The C / C crucible 1 described with reference to FIG.
Then, the bottom portion 5 is inserted into the body portion 2 so that the surface 5o of the notch portion 5n coincides with the surface 2b of the shoulder portion 2a, and the shoulder portion 2a is fitted into the notch portion 5n. Is fixed. This bottom 5 is replaced with the upper die 13 of the third molding die 12 described with reference to FIG.
Is formed using an upper mold in which a cylindrical space having an annular step is formed. Furthermore, the trunk 2
Is manufactured using a fourth mold 11 having a step as shown in FIG. The stepped portion of the fourth molding die 11 is a shoulder 2 composed of a surface 2b and a surface 2c.
It is provided to form a. This shoulder 2a
It is formed by winding a matrix material around a cloth made of carbon fiber and winding it around a step. Then, by cutting at the center of the fourth molding die 11,
Two body parts 2 are formed at one time. Thereby, the bottom 5
Can be integrally formed with the body 2 so that the body 2 having high mechanical strength can be formed.

In the C / C crucible 1 described with reference to FIG. 3B, the bottom 5 is inserted into the torso 2 so that the lower end 2d of the torso 2 coincides with the surface 5j of the shoulder 5h of the bottom 5. The part 2 and the bottom part 5 are fitted and fixed. The shoulder 5h is manufactured by using a molding die having a step for molding the lower surface 5k and the side surface of the bottom 5 and the annular shoulder 5h, instead of the third molding die 12 described in FIG.

In the C / C crucible 1 described with reference to FIG. 3 (c), the body 2 and the bottom 5 are precisely molded so that the inner side 2e of the body 2 and the side of the bottom 5 are in close contact with each other. ,
The body 2 is fixed using the surface frictional force between the inner surface 2 e of the body 2 and the side surface of the bottom 5. By forming the body 2 and the bottom 5 in this manner, the shapes of the first forming die 8 and the second forming die 10 for forming the body 2 and the third forming die 1 for forming the bottom 5 are formed.
2 can be made a simple shape, and the manufacturing cost can be reduced.

According to the manufacturing method as described above, since the body 2 is formed using the first and second cylindrical molds 8 and 10, conventionally, the body has been removed from the mold having hemispherical portions at both ends. Unlike the case where the and the bottom are integrally formed, a complicated winding method is not required, so that the body 2 does not wrinkle. Further, as in the conventional case, when the body and the bottom are integrally formed by a FW device from a mold having hemispherical portions at both ends,
A hole is formed at the bottom by the rotating shaft that supports the mold, and it is necessary to fill the hole after the bottom is formed. However, according to the present invention, this need is eliminated. Further, conventionally, in order to easily form a hemispherical portion, two C / C crucibles were simultaneously formed using a molding die having hemispherical portions at both ends, and the body portion was cut. This eliminates the need for cutting. In addition, the bottom portion 5 is formed by applying a prepreg to the spherical surface 15 of the lower die 14 and pressing the upper die 13 from above, thereby forming the bottom 5 easily. Thereby, the manufacturing period of the bottom part 5 can be shortened.

[0049]

According to the first aspect of the present invention, the body and the bottom are formed separately so that the body has a simple cylindrical shape and the bottom has a simple disk shape. ,
A C / C crucible can be easily formed. Further, the body and the bottom can be formed simultaneously. As a result, the molding period of the C / C crucible is shortened and the C / C crucible is shortened.
There is an effect that the C crucible can be easily mass-produced. In addition, since the body and the bottom are formed separately, there is an effect that thermal stress can easily escape, and a C / C crucible having high thermal stress can be formed.

According to the second aspect of the present invention, since the body is cylindrical, when the FW apparatus is used for molding, a cylindrical mold can be used, and the cloth made of carbon fibers and the winding of the carbon fibers can be easily performed. I can do it. As a result, the molding period of the body can be shortened, so that the molding period of the entire C / C crucible can be shortened, and the C / C crucible can be easily mass-produced. Even if a quartz crucible is inserted inside the body, the inside of the body is formed including a carbon fiber reinforced carbon composite material obtained by combining a cloth made of carbon fiber and a matrix material. The effect of suppressing the reaction with the contained SiO ₂ and suppressing damage to the C / C crucible can be achieved. Also,
Since the outside of the body is formed by winding carbon fibers, there is an effect that a C / C crucible having excellent mechanical strength against radial stress can be formed.

According to the third aspect of the present invention, the process of forming the body can be simplified by forming the body into a simple cylindrical shape. In addition, by forming the shape of the bottom portion into a simple disk shape, the process of forming the bottom portion can be simplified. Further, by separately performing the step of forming the body and the step of forming the bottom, the body and the bottom can be formed simultaneously. As a result, it is possible to shorten the molding period of the C / C crucible and to easily mass-produce the C / C crucible.

According to the fourth aspect of the present invention, since the molding die is cylindrical, the process of winding the carbon fiber cloth and the carbon fiber can be easily performed. As a result, the molding period of the body can be shortened, so that the molding period of the entire C / C crucible can be shortened, and the C / C crucible can be easily mass-produced. The inside of the body is formed including a step of winding a cloth made of carbon fiber while entangled with a matrix material, so that even if a quartz crucible is inserted inside the body, SiO ₂ contained in the quartz crucible is Is suppressed, and the C / C crucible in which the inside of the body is less likely to be damaged can be formed. In addition, by forming the outside of the body including the step of winding the carbon fiber, there is an effect that a C / C crucible having excellent mechanical strength against radial stress can be formed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a C / C crucible.

FIG. 2 is an enlarged partial cross-sectional view of FIG. 1, illustrating a fixing structure of a trunk and a bottom.

FIG. 3 is a diagram for explaining another fixing structure of a trunk and a bottom.

FIG. 4 is a diagram illustrating a molding die for molding a body.

FIG. 5 is a diagram illustrating a molding die for molding a bottom.

FIG. 6 is a diagram illustrating a process of assembling the body and the bottom.

[Explanation of symbols]

 Reference Signs List 1 C / C crucible 2 trunk 3 inner trunk 4 outer trunk 5 bottom 5a pedestal surface 6 fixing part 7 bolt 8 first molding die 9 rotating shaft 10 second molding die 11 fourth molding die 12 third molding die 13 Upper mold 14 Lower mold 15 Spherical 16 Support

Claims (4)

[Claims] 1. A single crystal pulling crucible formed of a carbon fiber reinforced carbon composite material, comprising a cylindrical body and a disk-shaped bottom, wherein the body and the bottom are formed separately. A single crystal pulling carbon fiber reinforced composite material crucible characterized in that the disk-shaped bottom portion is inserted into the cylindrical body portion and fixed at an end so as to be assembled. 2. A cloth made of carbon fiber in which a matrix material is entangled is wound around a cylindrical mold, and a cloth made of the carbon fiber and a matrix material are composited. The outer side surface of the cylindrical body portion is formed by winding a carbon fiber entangled with a matrix material around the cylindrical molding die, and the carbon fiber and the carbon fiber 2. The crucible for pulling a single crystal according to claim 1, wherein the crucible is formed of a carbon fiber reinforced carbon composite material obtained by compounding with a matrix material. 3. A method for manufacturing a single crystal pulling crucible formed of a carbon fiber reinforced carbon composite material, wherein a step of forming a cylindrical body and a step of forming the cylindrical body are performed in parallel. Forming a disc-shaped bottom, and assembling the disc-shaped bottom by inserting the disc-shaped bottom into the cylindrical body and fixing it at an end of the cylindrical body. Of producing a single crystal pulling carbon fiber reinforced carbon composite crucible. 4. The step of forming the cylindrical body portion includes: winding a matrix material around a cloth made of carbon fiber around a cylindrical mold so as to form an inner side surface of the body portion. The single crystal according to claim 3, further comprising: winding a carbon fiber while forming a matrix material around the cylindrical mold to form an outer side surface of the body. Manufacturing method of crucible for lifting.