JP5986534B2 - Silicon casting mold - Google Patents

Description

    The present invention relates to a silicon casting mold.

  Conventionally, in a semiconductor substrate manufacturing process or the like, polycrystalline silicon is formed by injecting a molten silicon melt into a mold and then solidifying it. Alternatively, the silicon raw material filled in the mold is melted at a high temperature and then solidified to form polycrystalline silicon (see, for example, Patent Document 1).

JP 2005-104743 A

    The silicon casting mold of Patent Document 1 is composed of one bottom member and four side members. However, when the silicon melt is injected into the mold, the silicon melt may leak from between the bottom surface member and the side member or between the plurality of side members.

  An object of the present invention is to provide a silicon casting mold in which leakage of silicon melt is prevented.

  (1) A mold according to the present invention is a mold for silicon casting, and includes a plurality of mold members formed of a carbon fiber reinforced carbon composite material and a leakage preventing member, and a plurality of mold members are combined. Thus, an accommodation space for accommodating the silicon raw material is formed, and the leakage preventing member is provided so as to cover the contact portions of the plurality of mold members.

  In this mold, a housing space is formed by combining a plurality of mold members. By injecting a molten silicon raw material (silicon solution) into the mold accommodating space, the silicon solution is accommodated in the accommodating space. Alternatively, the solid silicon material housed in the mold housing space is heated, so that the silicon material in the housing space becomes a silicon melt. Here, the contact portions between the plurality of mold members are covered with the leakage preventing member. Thereby, it is possible to prevent the silicon melt in the mold accommodating space from leaking out between the plurality of mold members.

  (2) The plurality of mold members include a bottom member positioned at the bottom of the storage space and a plurality of side wall members positioned at the side of the storage space, and the plurality of side wall members abut on the bottom member and the plurality of side walls. The housing space may be configured by the members abutting each other, and the leakage preventing member may be provided so as to close the side abutting portion that is the abutting portion between the plurality of side wall members from the outside.

  In this case, the accommodation space is configured by a plurality of side wall members coming into contact with the bottom member and a plurality of side wall members coming into contact with each other. Thereby, the structure of a casting_mold | template can be simplified. Moreover, the side contact part which is a contact part of several side wall members is obstruct | occluded from the outer side by the leakage prevention member. Thereby, it can prevent reliably that the silicon melt in the accommodation space of a casting_mold | template leaks outside from the side contact part of a some side wall member.

  (3) The leakage preventing member includes a first member that closes the side contact portions of the plurality of side wall members from the outside, and a second member that closes the contact portions of the plurality of side wall members and the first member from the outside. And a member.

  In this case, the side contact portions of the plurality of side wall members are closed from the outside by the first member, and the contact portions of the plurality of side wall members and the first member are closed from the outside by the second member. Thereby, the leakage of the silicon melt from the side contact portions of the plurality of side wall members adjacent to each other can be reliably prevented.

  (4) The first and second members may be integrally formed in an L shape.

  In this case, since the first and second members are integrally formed, the strength of the leakage preventing member is improved. Further, since there is no joining portion between the first member and the second member, leakage of the silicon melt from between the first member and the second member can be reliably prevented.

  (5) The mold may further include an integral reinforcing member provided so as to surround the outer peripheral edges of the plurality of side wall members and the leakage preventing member.

  According to this configuration, when the silicon solution is accommodated in the mold accommodating space, or when the silicon raw material in the mold accommodating space is melted, the side wall member or the leakage preventing member is not increased without increasing the thickness of the plurality of sidewall members and the leakage preventing member. It is possible to prevent the member from bending outward.

  (6) The reinforcing member is a planar body formed by laminating a plurality of planar woven fabrics, and the plurality of planar woven fabrics are planar woven fabrics and / or a plurality of planar woven fabrics. The one-dimensional woven fabric includes a planar woven fabric formed by repeatedly orthogonally crossing, and the plurality of planar woven fabrics constituting the planar body are orthogonal to the outer side surfaces of the plurality of side wall members and the leakage preventing member. In this way, a reinforcing member may be arranged.

  According to this configuration, the shear strength of the reinforcing member can be increased as compared with the case where the reinforcing member is disposed in a state in which the thickness direction of the reinforcing member is orthogonal to the outer side surfaces of the plurality of side wall members and the leakage preventing member. Thereby, the force which supports a some side wall member and a leak-proof member by a reinforcement member can be enlarged.

  (7) The leakage preventing member may be formed of a carbon fiber reinforced carbon composite material.

  In this case, the leakage preventing member is formed of the same material as the plurality of mold members. Therefore, the leakage preventing member can be easily joined to the plurality of mold members.

  (8) The plurality of mold members may be made of a porous material, and the matrix may be filled in the holes of the plurality of mold members in the accommodating space by chemical vapor impregnation treatment.

  In this case, the matrix (carbon material) is filled in the inner holes of the plurality of mold members formed of the porous material. Thereby, it is possible to prevent the silicon melt from leaking outside through the holes of the plurality of mold members.

  (9) A release material layer may be formed on the surfaces of the plurality of mold members in the accommodation space.

  In this case, the release material layer can prevent the silicon melt from leaking outside through the plurality of mold members. Also, the solidified silicon can be easily removed from the mold.

  According to the present invention, leakage of the silicon melt from the silicon casting mold is prevented.

It is an external appearance perspective view of the casting_mold | template which concerns on one embodiment of this invention. It is a top view of the casting_mold | template of FIG. It is a figure which shows the structure of a bottom member. It is a figure which shows the structure of a side wall member, a square member, and an auxiliary member. It is a perspective view which shows the assembly process of a casting_mold | template. It is a perspective view which shows the assembly process of a casting_mold | template. It is a perspective view which shows the assembly process of a casting_mold | template. It is a perspective view which shows the assembly process of a casting_mold | template. It is a perspective view which shows the assembly process of a casting_mold | template. It is a figure which shows the structure of a reinforcement member. It is a perspective view which shows the attachment process to the casting_mold | template of a reinforcement member. It is a perspective view which shows the attachment process to the casting_mold | template of a reinforcement member. It is a perspective view of the casting_mold | template provided with the some reinforcement member.

  Hereinafter, a silicon casting mold (hereinafter referred to as a mold) according to an embodiment of the present invention will be described with reference to the drawings.

(1) Configuration of mold FIG. 1 is an external perspective view of a mold according to an embodiment of the present invention. FIG. 2 is a plan view of the mold of FIG. As shown in FIGS. 1 and 2, the mold 100 includes a bottom member 10, two sidewall members 20 and two sidewall members 30, four corner members 40, four corner members 50, and four auxiliary members 60.

  The bottom member 10, the side wall members 20, 30, the corner members 40, 50, and the auxiliary member 60 are formed of a carbon fiber reinforced carbon composite material (C / C composite). Further, the CVI (Chemical Vapor Impregnation) process is performed on the surfaces of the bottom member 10, the side wall members 20 and 30, the corner members 40 and 50, and the auxiliary member 60. As a result, the pores of the bottom member 10, the side wall members 20 and 30, the corner members 40 and 50, and the auxiliary member 60 are filled with a carbon material (matrix) such as silicon carbide.

  The two side wall members 20 and the two side wall members 30 are arranged on the bottom member 10 so as to form a rectangular frame, whereby the main body portion 80 is configured. The corner member 40 and the corner member 50 constitute an L-shaped closing member 90. From the corner members 40, 50 to each of the four abutting portions (corner portions in this example) of the main body portion 80 comprising the side wall members 20, 30 so as to close the joint portion between the side wall member 20 and the side wall member 30. The closing member 90 is joined. The four auxiliary members 60 are joined to the upper surface of the bottom member 10 and joined to the outer side surfaces of the two side wall members 20 and the two side wall members 30, respectively.

  As described above, the bottom member 10, the two side wall members 20, and the two side wall members 30 are surrounded by the four closing members 90 and the four auxiliary members 60 from the outside of the main body 80, thereby forming the mold 100. The bottom member 10, the two side wall members 20, and the two side wall members 30 form a rectangular parallelepiped-shaped accommodation space V whose top is opened. The molten silicon raw material (silicon solution) is injected into the storage space V of the main body 80, whereby the silicon solution is stored in the storage space V. Alternatively, a solid silicon raw material is stored in the storage space V of the main body 80, and the silicon raw material in the storage space V is heated, so that the silicon raw material becomes a silicon melt.

  Here, since the matrix is filled in the pores of the upper surface of the bottom member 10 and the inner side surfaces of the side wall members 20 and 30 by the CVI treatment, the silicon melt is passed through the pores of the bottom member 10 and the side wall members 20 and 30. Leakage to the outside can be prevented. Thereafter, the silicon melt is cooled and solidified in the accommodation space V, whereby polycrystalline silicon is formed. After the polycrystalline silicon is formed, the mold 100 is disassembled to remove the polycrystalline silicon from the mold 100.

(2) Details of Bottom Member, Side Wall Member, Corner Member, and Auxiliary Member FIG. 3 is a diagram showing a configuration of the bottom member 10. FIG. 4 is a diagram showing the configuration of the side wall members 20 and 30, the corner members 40 and 50, and the auxiliary member 60. FIG. 3 shows a plan view of the bottom member 10, a side view seen from one direction, and a side view seen from the other direction.

  As shown in FIG. 3, the bottom member 10 is a substantially square or substantially rectangular plate-like member having four sides L11, L12, L13, and L14. The sides L11 and L12 face each other, and the sides L13 and L14 face each other. In the bottom member 10, three rectangular through holes 11 are formed so as to be aligned along the side L11, and three rectangular through holes 11 are formed so as to be aligned along the side L12. Further, three rectangular through holes 12 are formed in the bottom member 10 so as to be aligned along the side L13, and three rectangular through holes 12 are formed so as to be aligned along the side L14.

  Rectangular through-holes 13 are formed in the vicinity of both ends of the side L11 of the bottom member 10, and rectangular through-holes 13 are formed in the vicinity of both ends of the side L12. A rectangular through hole 14 is formed in the vicinity of both ends of the side L13 of the bottom member 10, and a rectangular through hole 14 is formed in the vicinity of both ends of the side L14. Two screw holes 15 are formed so as to be aligned along the side L11 of the bottom member 10, and two screw holes 15 are formed so as to be aligned along the side L12. Further, two screw holes 15 are formed so as to be aligned along the side L13 of the bottom member 10, and two screw holes 15 are formed so as to be aligned along the side L14.

  On the side surface along the side L <b> 11 of the bottom member 10, three circular bottomed holes 16 that respectively penetrate the three through holes 11 and extend by a predetermined distance are formed. Similarly, on the side surface along the side L12 of the bottom member 10, there are formed three circular bottomed holes 16 that respectively penetrate the three through holes 11 and extend by a predetermined distance. On the side surface along the side L <b> 13 of the bottom member 10, three circular bottomed holes 17 penetrating the three through holes 12 and extending a predetermined distance are formed. Similarly, on the side surface along the side L14 of the bottom member 10, three circular bottomed holes 17 extending through a predetermined distance through the three through holes 12 are formed.

  On the side surface of the bottom member 10 along the side L <b> 11 of the bottom member 10, two circular bottomed holes 18 that pass through the two through holes 13 and extend by a predetermined distance are formed. Similarly, two bottomed holes 18 having a circular shape extending through a predetermined distance through the two through holes 13 are formed on the side surface of the bottom member 10 along the side L12. On the side surface along the side L13 of the bottom member 10, two circular bottomed holes 19 are formed that extend through a predetermined distance through the two through holes 14, respectively. Similarly, on the side surface along the side L14 of the bottom member 10, two circular bottomed holes 19 penetrating the two through holes 14 and extending a predetermined distance are formed.

  FIG. 4A shows a plan view of the side wall member 20 and a side view seen from one direction. As shown in FIG. 4A, the side wall member 20 is a substantially rectangular plate-like member having four sides L21, L22, L23, and L24. The sides L21 and L22 face each other, and the sides L23 and L24 face each other. Three protrusions 21 are formed on the side L <b> 23 of the side wall member 20. By forming notches 23 at the corners between the sides L21 and L23 and at the corners between the sides L22 and L23, respectively, the protruding portions at the corners between the sides L21 and L24 and the corners between the sides L22 and L24, respectively. 22 is formed.

  Each of the three protrusions 21 is formed with a circular through hole 24. Each of the two protrusions 22 is formed with a circular through hole 25. Two screw holes 26 are formed between the two protrusions 22 so as to be arranged at a predetermined interval. A circular bottomed hole 27 extending by a predetermined distance is formed on the end surface of the side wall member 20 parallel to the sides L21 and L22 in the notch 23.

  FIG. 4B shows a plan view of the side wall member 30 and a side view seen from one direction. As shown in FIG. 4B, the side wall member 30 is a substantially rectangular plate-like member having four sides L31, L32, L33, and L34. The sides L31 and L32 face each other, and the sides L33 and L34 face each other. Three protrusions 31 are formed on the side L33 of the side wall member 30. By forming notches 33 at the corners between the sides L31 and L34 and at the corners between the sides L32 and L34, respectively, the protruding portions at the corners between the sides L31 and L33 and the corners between the sides L32 and L33. 32 is formed.

  Each of the three protrusions 31 is formed with a circular through hole 34. Each of the two protrusions 32 is formed with a circular through hole 35. Two screw holes 36 are formed between the two notches 33 so as to be arranged at a predetermined interval. A circular bottomed hole 37 extending by a predetermined distance is formed on the end surface of the side wall member 30 parallel to the sides L31 and L32 in the notch 33.

  FIG. 4C shows a plan view of the corner member 40 and a side view seen from one direction. As shown in FIG. 4C, the corner member 40 is a substantially square plate-like member having four sides L41, L42, L43, and L44. The sides L41 and L42 face each other, and the sides L43 and L44 face each other. A protruding portion 41 is formed on the side L43 of the corner member 40. By forming notches 43 at the corners between the sides L41 and L43 and at the corners between the sides L41 and L44, the protrusions 42 are formed at substantially the center of the side L41.

  A circular through hole 44 is formed in the protrusion 41. A circular through hole 45 is formed in the protrusion 42. A through hole 46 is formed at the corner between the sides L42 and L44. A circular bottomed hole 47 extending by a predetermined distance is formed on the end face of the square member 40 parallel to the side L41 in the two notches 43.

  FIG. 4D shows a plan view of the corner member 50 and a side view seen from one direction. As shown in FIG. 4D, the corner member 50 is a substantially square plate-like member having four sides L51, L52, L53, and L54. The sides L51 and L52 face each other, and the sides L53 and L54 face each other. On the side L53 of the corner member 50, a protruding portion 51 is formed. By forming the notch 53 at a substantially central portion of the side L51, the protruding portion 52 is formed at the corner between the sides L51 and L53 and the corner between the sides L51 and L54, respectively.

  A circular through hole 54 is formed in the protrusion 51. Circular protrusions 55 are formed in the two protrusions 52, respectively. A through hole 56 is formed at the corner between the sides L52 and L54. A circular bottomed hole 57 extending by a predetermined distance is formed on the end face of the square member 50 parallel to the side L51 in the notch 53.

  FIG. 4E shows a plan view of the auxiliary member 60 and a side view seen from one direction. As shown in FIG. 4E, the auxiliary member 60 is a substantially rectangular plate-like member having four sides L61, L62, L63, and L64. The sides L61 and L62 face each other, and the sides L63 and L64 face each other. Cutout portions 61 are formed at the corners between the sides L61 and L64 and at the corners between the sides L62 and L64, respectively. Two through holes 62 are formed in the auxiliary member 60 so as to be aligned in a direction parallel to the sides L63 and L64.

(3) Mold Assembly Process FIGS. 5 to 9 are perspective views showing the mold 100 assembly process. Hereinafter, the assembly process of the mold 100 will be described with reference to FIGS. In the description of FIGS. 5 to 9, one side wall member 20 is referred to as a side wall member 20A, and the other side wall member 20 is referred to as a side wall member 20B. One side wall member 30 is referred to as a side wall member 30A, and the other side wall member 30 is referred to as a side wall member 30B.

  As shown in FIG. 5, the three protrusions 31 of the side wall member 30 </ b> A are fitted into the three through holes 12 on the side L <b> 13 side of the bottom member 10, so that the side wall member 30 </ b> A is attached to the bottom member 10. . Here, the three bottomed holes 17 on the side L13 side of the bottom member 10 and the through holes 34 of the three protrusions 31 of the side wall member 30A overlap each other in a straight line. In this state, fixing pins (not shown) are respectively inserted into the three bottomed holes 17 on the side L13 side of the bottom member 10 and the through holes 34 of the three protruding portions 31 of the side wall member 30A. Thereby, the side wall member 30 </ b> A is fixed to the bottom member 10.

  Similarly, the side wall member 30 </ b> B is attached to the bottom member 10 by fitting the three protruding portions 31 of the side wall member 30 </ b> B into the three through holes 12 on the side L <b> 14 side of the bottom member 10. Here, the three bottomed holes 17 on the side L14 side of the bottom member 10 and the through holes 34 of the three protruding portions 31 of the side wall member 30B overlap each other in a straight line. In this state, unillustrated fixing pins are respectively inserted into the three bottomed holes 17 on the side L14 side of the bottom member 10 and the through holes 34 of the three protruding portions 31 of the side wall member 30B. Thereby, the side wall member 30 </ b> B is fixed to the bottom member 10.

  As shown in FIG. 6, the three protruding portions 21 of the side wall member 20 </ b> A are fitted into the three through holes 11 on the side L <b> 11 side of the bottom member 10, whereby the side wall member 20 </ b> A is attached to the bottom member 10. In this case, one protrusion 22 of the side wall member 20A is fitted into one notch 33 of the side wall member 30A, and one protrusion 32 of the side wall member 30A is one notch 23 of the side wall member 20A. Fitted. In addition, the other protrusion 22 of the side wall member 20A is fitted into one notch 33 of the side wall member 30B, and one protrusion 32 of the side wall member 30B is connected to the other notch 23 of the side wall member 20A. Mated.

  Here, the through hole 25 of the one protruding portion 22 of the side wall member 20A and the bottomed hole 37 of the one notch portion 33 of the side wall member 30A overlap each other in a straight line. In this state, a fixing pin (not shown) is inserted into the through hole 25 of the one protruding portion 22 of the side wall member 20A and the bottomed hole 37 of the one notch portion 33 of the side wall member 30A. Similarly, the through hole 35 of one protrusion 32 of the side wall member 30A and the bottomed hole 27 of one notch 23 of the side wall member 20A overlap each other in a straight line. In this state, a fixing pin (not shown) is inserted into the through hole 35 of the one protruding portion 32 of the side wall member 30A and the bottomed hole 27 of the one notch portion 23 of the side wall member 20A. Thereby, the side wall member 20A and the side wall member 30A are fixed.

  Further, the through hole 25 of the other protrusion 22 of the side wall member 20A and the bottomed hole 37 of the one notch 33 of the side wall member 30B overlap each other in a straight line. In this state, a fixing pin (not shown) is inserted into the through hole 25 of the other protruding portion 22 of the side wall member 20A and the bottomed hole 37 of one notch portion 33 of the side wall member 30B. Similarly, the through hole 35 of one protrusion 32 of the side wall member 30B and the bottomed hole 27 of the other notch 23 of the side wall member 20A overlap each other in a straight line. In this state, a fixing pin (not shown) is inserted through the through hole 35 of one projecting portion 32 of the side wall member 30B and the bottomed hole 27 of the other notch portion 23 of the side wall member 20A. Thereby, the side wall member 20A and the side wall member 30B are fixed.

  Further, the three bottomed holes 16 on the side L11 side of the bottom member 10 and the through holes 24 of the three protruding portions 21 of the side wall member 20A overlap each other in a straight line. In this state, fixing pins (not shown) are respectively inserted into the three bottomed holes 16 on the side L11 side of the bottom member 10 and the through holes 24 of the three protruding portions 21 of the side wall member 20A. Thereby, the side wall member 20 </ b> A is fixed to the bottom member 10.

  The side wall member 20 </ b> B is disposed on the bottom member 10 by fitting the three protrusions 21 of the side wall member 20 </ b> B into the three through holes 11 on the side L <b> 12 side of the bottom member 10. In this case, one protrusion 22 of the side wall member 20B is fitted into the other notch 33 of the side wall member 30A, and the other protrusion 32 of the side wall member 30A is one notch 23 of the side wall member 20B. Fitted. The other protrusion 22 of the side wall member 20B is fitted into the other notch 33 of the side wall member 30B, and the other protrusion 32 of the side wall member 30B is connected to the other notch 23 of the side wall member 20B. Mated.

  Here, the through hole 25 of one protrusion 22 of the side wall member 20B and the bottomed hole 37 of the other notch 33 of the side wall member 30A overlap each other in a straight line. In this state, a fixing pin (not shown) is inserted through the through hole 25 of one protruding portion 22 of the side wall member 20B and the bottomed hole 37 of the other notch portion 33 of the side wall member 30A. Similarly, the through hole 35 of the other protrusion 32 of the side wall member 30A and the bottomed hole 27 of the one notch 23 of the side wall member 20B overlap each other in a straight line. In this state, a fixing pin (not shown) is inserted through the through hole 35 of the other protruding portion 32 of the side wall member 30A and the bottomed hole 27 of the one cutout portion 23 of the side wall member 20B. Thereby, the side wall member 20B and the side wall member 30A are fixed.

  Further, the through hole 25 of the other protrusion 22 of the side wall member 20B and the bottomed hole 37 of the other notch 33 of the side wall member 30B overlap each other in a straight line. In this state, a fixing pin (not shown) is inserted through the through hole 25 of the other protrusion 22 of the side wall member 20B and the bottomed hole 37 of the other notch 33 of the side wall member 30B. Similarly, the through hole 35 of the other protrusion 32 of the side wall member 30B and the bottomed hole 27 of the other notch 23 of the side wall member 20B overlap each other in a straight line. In this state, a fixing pin (not shown) is inserted through the through hole 35 of the other protrusion 32 of the side wall member 30B and the bottomed hole 27 of the other notch 23 of the side wall member 20B. Thereby, the side wall member 20B and the side wall member 30B are fixed.

  Further, the three bottomed holes 16 on the side L12 side of the bottom member 10 and the through holes 24 of the three protruding portions 21 of the side wall member 20B overlap each other in a straight line. In this state, unillustrated fixing pins are respectively inserted into the three bottomed holes 16 on the side L12 side of the bottom member 10 and the through holes 24 of the three protruding portions 21 of the side wall member 20B. Thereby, the side wall member 20 </ b> B is fixed to the bottom member 10.

  In this way, the bottom member 10 and the side wall members 20A, 20B, 30A, 30B are joined, the side wall member 20A is joined to the side wall members 30A, 30B, and the side wall member 20B is joined to the side wall members 30A, 30B. Is done. Thereby, the main body 80 is configured.

  As shown in FIG. 7, the protrusion 41 of the corner member 40 is fitted into the notch 53 of the corner member 50, and the two protrusions 52 of the corner member 50 are respectively connected to the two protrusions 42 of the corner member 40. Mated. Here, the through hole 45 of the protrusion 42 of the corner member 40 and the bottomed hole 57 of the notch 53 of the corner member 50 overlap in a straight line. In this state, a fixing pin (not shown) is inserted into the through hole 45 of the protrusion 42 of the corner member 40 and the bottomed hole 57 of the notch 53 of the corner member 50.

  Further, the through holes 55 of the two projecting portions 52 of the corner member 50 and the bottomed holes 47 of the two notched portions 43 of the corner member 40 respectively overlap with each other. In this state, fixing pins (not shown) are respectively inserted into the through holes 55 of the two protrusions 52 of the corner member 50 and the bottomed holes 47 of the two notches 43 of the corner member 40. Thereby, the corner member 40 and the corner member 50 are joined, and the closure member 90 is comprised.

  As shown in FIG. 8, the protrusions 41 of the corner members 40 of the plurality of closing members 90 are respectively fitted into the plurality of through holes 13 of the bottom member 10, and the protrusions of the corner members 50 of the plurality of closing members 90. 51 are respectively fitted into the plurality of through holes 14 of the bottom member 10. Accordingly, the plurality of corner members 40 and 50 are attached to the bottom member 10.

  Here, the plurality of bottomed holes 18 of the bottom member 10 and the through holes 44 of the projecting portions 41 of the plurality of corner members 40 overlap each other in a straight line. In this state, fixing pins (not shown) are respectively inserted into the plurality of bottomed holes 18 of the bottom member 10 and the through holes 44 of the protruding portions 41 of the plurality of corner members 40. As a result, the plurality of corner members 40 are fixed to the bottom member 10.

  Similarly, the plurality of bottomed holes 19 of the bottom member 10 and the through-holes 54 of the protruding portions 51 of the plurality of corner members 50 overlap each other in a straight line. In this state, fixing pins (not shown) are respectively inserted into the plurality of bottomed holes 19 of the bottom member 10 and the through holes 54 of the protruding portions 51 of the plurality of corner members 50. Thereby, the plurality of corner members 50 are fixed to the bottom member 10.

  Further, the through holes 46 of the plurality of corner members 40 and the plurality of screw holes 26 of the side wall members 20A and 20B overlap in a straight line. In this state, screws (not shown) are respectively inserted into the plurality of screw holes 26 of the side wall members 20A and 20B through the through holes 46 of the plurality of corner members 40. Similarly, the through holes 56 of the plurality of corner members 50 and the plurality of screw holes 36 of the side wall members 30A and 30B overlap in a straight line. In this state, screws (not shown) are respectively inserted into the plurality of screw holes 36 of the side wall members 30A and 30B through the through holes 56 of the plurality of corner members 50.

  In this example, four corner members 40 are joined to the outer side surfaces of the two sidewall members 20, and four corner members 50 are joined to the outer side surfaces of the two sidewall members 30. As a result, the closing member 90 composed of the corner members 40, 50 is attached to each of the four corners of the main body 80 composed of the side wall members 20A, 20B, 30A, 30B.

  As shown in FIG. 9, a plurality of auxiliary members 60 are disposed on the bottom member 10. In this case, the side surfaces along the side L64 of the pair of auxiliary members 60 are in contact with the outer side surfaces of the side wall members 20A and 20B, respectively. Moreover, the notch part 61 and the square member 40 of one pair of auxiliary member 60 fit. Similarly, the side surfaces along the side L64 of the other pair of auxiliary members 60 are in contact with the outer side surfaces of the side wall members 30A and 30B, respectively. Further, the notch 61 and the corner member 50 of the other pair of auxiliary members 60 are fitted.

  Here, the plurality of two through holes 62 of the plurality of auxiliary members 60 and the plurality of screw holes 15 of the bottom member 10 overlap each other in a straight line. In this state, screws (not shown) are respectively inserted into the plurality of two through holes 62 of the plurality of auxiliary members 60 and the plurality of screw holes 15 of the bottom member 10. As a result, the plurality of auxiliary members 60 are fixed to the bottom member 10.

  The corner members 40 and 50 and the auxiliary member 60 are planar bodies formed by laminating planar woven fabrics. The planar woven fabric is, for example, a plane woven fabric (hereinafter referred to as 2D cloth) knitted in two dimensions, or a plane obtained by orthogonalizing a woven fabric knitted in one dimension (hereinafter referred to as 1D cloth). Woven fabric. The corner members 40 and 50 and the auxiliary member 60 are disposed such that the surface of the planar body is orthogonal to the outer side surfaces of the side wall members 20 and 30.

  According to this configuration, the shearing of the corner members 40, 50 and the auxiliary member 60 is compared to the case where the corner members 40, 50 and the auxiliary member 60 are arranged in a state where the thickness direction thereof is orthogonal to the outer side surfaces of the side wall members 20, 30. The strength can be increased. Thereby, the force which supports the side wall members 20 and 30 by the corner members 40 and 50 and the auxiliary member 60 can be enlarged.

  In this way, one closing member 90 is joined to the outer side surface of the side wall members 20A and 30A, and the other one closing member 90 is joined to the outer side surface of the side wall members 20A and 30B. Further, another one closing member 90 is joined to the outer side surface of the side wall members 20B and 30A, and the remaining one closing member 90 is joined to the outer side surface of the side wall members 20B and 30B. Further, the four closing members 90 are joined to the bottom member 10.

  The mold 100 of FIG. 1 is assembled through the above steps. Note that after the formation of the polycrystalline silicon, the mold 100 is disassembled in the reverse process of the assembly process.

(3) Reinforcing member When the thickness of the side wall members 20 and 30 is small, a reinforcing member may be provided on the mold 100. FIG. 10 is a diagram illustrating the configuration of the reinforcing member. FIG. 10 shows a plan view of the reinforcing member 70 and a side view seen from one direction. The reinforcing member 70 is formed of a C / C composite.

  As shown in FIG. 10A, the reinforcing member 70 has a substantially square frame shape or a substantially rectangular frame shape. The inner surface and the outer surface of the central part of each of the four sides of the reinforcing member 70 are recessed inward. Thereby, each of the four corners of the reinforcing member 70 protrudes outward. Specifically, the inner surface of the reinforcing member 70 has a shape along the outer surfaces of the two side wall members 20, the two side wall members 30, and the four closing members 90 in FIG. 1 in a plane parallel to the bottom member 10. Accordingly, the reinforcing member 70 is provided so as to surround the outer peripheral edges of the two side wall members 30 and the four closing members 90.

  As shown in FIG. 10 (b), only the inner surface of the central part of each of the four sides of the reinforcing member 70 is recessed inward, and the outer surface may not be recessed inward. Alternatively, only the inner surface of the central part of each of the four sides of the reinforcing member 70 may be recessed inward, and the outer surface may protrude outward.

  11 and 12 are perspective views showing a process of attaching the reinforcing member 70 to the mold 100. FIG. When the reinforcing member 70 is attached to the mold 100, a plurality of fixing screws 71 are attached to the outer surfaces of the two side wall members 20 and the two side wall members 30 so as to be aligned in parallel with the bottom member 10 as shown in FIG. It is done.

  As shown in FIG. 12, the reinforcing member 70 is fitted into the mold 100 from above and placed on the plurality of fixing screws 71. Accordingly, the reinforcing member 70 is attached to the mold 100 in a state where the inner surface of the reinforcing member 70 is in contact with the outer surfaces of the two side wall members 20, the two side wall members 30, the four corner members 40, and the four corner members 50. The reinforcing member 70 is preferably located at a substantially central portion in the vertical direction of the mold 100.

  The reinforcing member 70 is a planar body formed by laminating planar woven fabrics. The planar woven fabric is, for example, a planar woven fabric in which 2D cloth or 1D cloth is orthogonal. The reinforcing member 70 is disposed so that the surface of the planar body is orthogonal to the outer side surfaces of the side wall members 20 and 30.

  According to this configuration, the shear strength of the reinforcing member 70 can be increased as compared with the case where the reinforcing member 70 is disposed in a state where the thickness direction thereof is orthogonal to the outer side surfaces of the side wall members 20 and 30. Thereby, the force which supports the side wall members 20 and 30 and the closure member 90 by the reinforcement member 70 can be enlarged.

  By attaching the reinforcing member 70 to the mold 100, the two side wall members 20, the two side wall members 30, and the four closing members 90 are reinforced. Thereby, even when the side wall members 20 and 30 and the closing member 90 are small in thickness, when the silicon solution is stored in the storage space V of the main body 80 or when the silicon raw material is melted in the storage space V of the mold 100. The side wall members 20 and 30 and the closing member 90 are prevented from being bent outward.

(4) Effects In the mold 100 according to the present embodiment, the two side wall members 20 and the two side wall members 30 are joined to the bottom member 10 and the two side wall members 20 and the two side wall members 30 are joined to each other. Thus, the main body 80 having the accommodation space V is configured. Thereby, the structure of the main-body part 80 can be simplified.

  Four closing members 90 composed of the corner members 40 and 50 are joined to the outer surface of the main body 80. Thereby, the junction part between the side wall members 20 and 30 is each obstruct | occluded from the outer side of the main-body part 80. FIG. In addition, the auxiliary member 60 is joined to the outside of the two joint portions between the bottom member 10 and the side wall member 20 and the two joint portions between the bottom member 10 and the side wall member 30. Thereby, the joint portion between the upper surface of the bottom member 10 and the lower surface of the side wall member 20 and the joint portion between the upper surface of the bottom member 10 and the lower surface of the side wall member 30 are closed.

  In this state, the molten silicon raw material is injected into the storage space V of the main body 80, whereby the silicon solution is stored in the storage space V. Alternatively, the silicon raw material housed in the housing space V of the main body 80 is heated, so that the silicon raw material in the housing space V becomes a silicon melt. Here, the joint portion between the bottom member 10, the two side wall members 20, and the two side wall members 30 is closed by the four closing members 90 and the four auxiliary members 60. As a result, it is possible to prevent the silicon melt in the accommodating space V of the main body 80 from leaking out between the bottom member 10, the two side wall members 20, and the two side wall members 30.

(5) Other Embodiments (5-1) In the above embodiment, even if a release material layer containing silicon nitride, silicon carbide, or silicon dioxide is formed on the surfaces of the bottom member 10 and the side wall members 20, 30 Good. In this case, the release material layer can prevent the silicon melt from leaking outside through the pores of the bottom member 10 and the side wall members 20 and 30. Further, the solidified polycrystalline silicon can be easily removed from the main body 80.

  In the case where the release material layer is formed on the surfaces of the bottom member 10 and the side wall members 20, 30, the CVI process may not be performed on the surfaces of the bottom member 10 and the side wall members 20, 30. Alternatively, the surface of the bottom member 10 and the side wall members 20 and 30 may be subjected to CVI treatment and a release material layer may be formed.

  (5-2) In the said embodiment, although the closure member 90 attached to the side wall members 20 and 30 is comprised by joining of the separate square members 40 and 50, it is not limited to this. The closing member 90 attached to the side wall members 20 and 30 may be integrally formed. In this case, since the corner members 40 and 50 are integrally formed, the strength of the closing member 90 is improved. In addition, since there is no joining portion between the corner member 40 and the corner member 50, leakage of the silicon melt from between the corner member 40 and the corner member 50 can be reliably prevented.

  (5-3) In the above embodiment, one reinforcing member 70 is provided in the mold 100, but the present invention is not limited to this. When the vertical dimension of the mold 100 is large, a plurality of reinforcing members 70 may be provided on the main body 80 of the mold 100. FIG. 13 is a perspective view of the mold 100 provided with a plurality of reinforcing members 70. In the example of FIG. 13, three reinforcing members 70 a, 70 b, 70 c are provided on the main body 80 of the mold 100 as the plurality of reinforcing members 70.

  In the step of attaching the reinforcing members 70 a to 70 c to the mold 100, first, a plurality of fixing screws are provided on the outer surfaces of the two side wall members 20 and the two side wall members 30 so as to be aligned in parallel with the bottom member 10 at the first height. 71a is attached. Here, the lower reinforcing member 70a is fitted into the mold 100 from above and placed on the plurality of fixing screws 71a at the first height.

  Next, a plurality of fixing screws 71b are attached to the outer surfaces of the two side wall members 20 and the two side wall members 30 so as to be arranged in parallel with the bottom member 10 at a second height located above the first height. It is done. Here, the middle reinforcing member 70b is fitted into the mold 100 from above and placed on the plurality of fixing screws 71b at the second height.

  Thereafter, a plurality of fixing screws 71 c are attached to the outer surfaces of the two side wall members 20 and the two side wall members 30 so as to be arranged in parallel with the bottom member 10 at a third height located above the second height. . Here, the upper reinforcing member 70c is fitted into the mold 100 from above and placed on the plurality of fixing screws 71c at the third height.

  By attaching the plurality of reinforcing members 70 a to 70 c to the mold 100, the two side wall members 20 and the two side wall members 30 are reinforced. Thereby, even when the vertical dimension of the mold 100 is large, when the silicon solution is accommodated in the accommodating space V of the main body 80 or when the silicon raw material is melted in the accommodating space V of the mold 100, 30 is prevented from bending outward.

  (5-4) In the above-described embodiment, the closing member 90 is provided so as to close the side contact portion that is the contact portion of the plurality of side wall members 20 and 30 from the outside, but is not limited thereto. The closing member 90 may be provided so as to close a side contact portion that is a contact portion of the plurality of side wall members 20 and 30 from the inside.

  (5-5) The closing member 90 may be joined to the plurality of side wall members 20 and 30. In the above embodiment, since the closing member 90 is formed of the same material (C / C composite) as the plurality of side wall members 20, 30, the closing member 90 is easily joined to the plurality of side wall members 20, 30. be able to. On the other hand, when the closing member 90 is not joined to the plurality of side wall members 20, 30, the closing member 90 may be formed of a material different from that of the plurality of side wall members 20, 30.

(6) Correspondence between each component of claim and each part of embodiment The following describes an example of a correspondence between each component of the claim and each part of the embodiment. It is not limited.

  The mold 100 is an example of the mold, the bottom member 10 and the side wall members 20 and 30 are examples of the mold member, the accommodation space V is an example of the accommodation space, the closing member 90 is an example of the leakage prevention member, and the bottom portion The material 10 is an example of a bottom member. The side wall members 20 and 30 are examples of the side wall member, the corner member 40 is an example of the first member, the corner member 50 is an example of the second member, and the reinforcing member 70 is an example of the reinforcing member.

  As each constituent element in the claims, various other elements having configurations or functions described in the claims can be used.

  The present invention can be effectively used for various silicon casting molds.

DESCRIPTION OF SYMBOLS 10 Bottom member 11-14, 24, 25, 34, 35, 44-46, 54-56, 62 Through-hole 15, 26, 36 Screw hole 16-19, 27, 37, 47, 57 Bottomed hole 20, 20A , 20B, 30, 30A, 30B Side wall member 21, 22, 31, 32, 41, 42, 51, 52 Protruding part 23, 33, 43, 53, 61 Notch part 40, 50 Square member 60 Auxiliary member 70, 70a- 70c Reinforcement member 71, 71a-71c Fixing screw 90 Closure member 100 Mold L11-L14, L21-L24, L31-L34, L41-L44, L51-L54, L61-L64 Side V Storage space

Claims (9)

A mold for silicon casting,
A plurality of mold members formed of carbon fiber reinforced carbon composite material;
A leakage prevention member,
An accommodation space for accommodating a silicon raw material is formed by combining the plurality of mold members,
The said sealing member is a casting_mold | template provided so that the contact part of these casting_mold | template members may be covered. The plurality of mold members are:
A bottom member located at the bottom of the accommodating space;
A plurality of side wall members located on the side of the housing space,
The housing space is configured by the plurality of side wall members abutting on the bottom member and the plurality of side wall members abutting each other.
The mold according to claim 1, wherein the leakage prevention member is provided so as to close a side contact portion that is a contact portion between the plurality of side wall members from the outside. The leakage preventing member includes a first member that closes the side contact portions of the plurality of side wall members from the outside, and a first member that closes the contact portions of the plurality of side wall members and the first member from the outside. The mold according to claim 2, comprising two members. The mold according to claim 3, wherein the first and second members are integrally formed in an L shape. The casting_mold | template as described in any one of Claims 2-4 further provided with the integral reinforcement member provided so that the outer periphery of these side wall members and the said leakage prevention member may be enclosed. The reinforcing member is a planar body formed by laminating a plurality of planar woven fabrics,
The plurality of planar woven fabrics include a planar woven fabric knitted in two dimensions and / or a planar woven fabric formed by repeatedly orthogonally crossing a plurality of one-dimensional woven fabrics,
The mold according to claim 5, wherein the reinforcing member is arranged so that the plurality of planar woven fabrics constituting the planar body are orthogonal to the outer side surfaces of the plurality of side wall members and the leakage preventing member. The mold according to any one of claims 1 to 6, wherein the leakage preventing member is formed of a carbon fiber reinforced carbon composite material. The plurality of mold members are made of a porous material,
The mold according to claim 1, wherein the matrix is filled in the holes of the plurality of mold members in the accommodation space by a chemical vapor impregnation process. The mold according to any one of claims 1 to 8, wherein a release material layer is formed on the surfaces of the plurality of mold members in the accommodation space.

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