Graphite electrode, electrode device and electrode

Abstract

To provide a graphite electrode used similarly to a conventional graphite electrode while reducing a processing cost.SOLUTION: A graphite electrode used for arc discharge for manufacturing a quartz crucible and including a graphite electrode main body and a connection part projecting from the graphite electrode main body can be connected to an electrode device for energizing the graphite electrode through the connection part. The connection part has a shape connected to the electrode device by driving.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a graphite electrode, an electrode device, and an electrode, and more particularly to a graphite electrode and electrode device used in arc discharge for manufacturing a quartz crucible, and an electrode connected thereto. [Background technology]

[0002] Most silicon single crystals used as substrates for single crystal semiconductor materials are manufactured by the so-called Czochralski method, in which silicon polycrystals are melted in a quartz crucible, brought into contact with a seed crystal, and then grown into a crystal. There are several types of quartz crucibles used in this method of manufacturing silicon single crystals, depending on the manufacturing method. In practice, quartz crucibles are used that are manufactured by filling silicon dioxide powder (raw quartz powder) along the inner circumferential surface of a rotatable hollow mold, and heating and melting the silicon dioxide powder by arc discharge using a graphite electrode while rotating the mold. Many embodiments of the graphite electrodes used in the arc discharge for manufacturing quartz crucibles have been disclosed (for example, Patent Documents 1 to 5).

[0003] The graphite electrode is used by connecting it to an electrode device (e.g., made of copper) for passing electricity (see Patent Documents 1 to 5). The connection method is usually performed by providing a male screw on the graphite electrode and a female screw on the electrode device, and screwing them together, thereby connecting the graphite electrode to the electrode device.

[0004] A schematic diagram of a graphite electrode being screwed into an electrode device is shown in Fig. 2. As shown in Fig. 2(a), a graphite electrode 111 is provided with a connecting part 114 having a male screw shape on a graphite electrode body 112. The graphite electrode body 112 may have various external shapes, such as a cylindrical shape.

[0005] 2(b), the electrode device 121 is formed with a holding portion (a concave coupling portion) 126 having a female thread shape that can be screwed into the thread of the connection portion 114 of the graphite electrode 111. The electrode device 121 has various external shapes, such as a cylindrical shape. The graphite electrode 111 and the electrode device 121 are screwed and connected at the connection portion 114 and the holding portion 126, as shown in FIG. 2(c), to form an electrode 131. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 8-34628 [Patent Document 2] JP 2016-11238 A [Patent Document 3] JP 2010-180123 A [Patent Document 4] JP 2017-65962 A [Patent Document 5] JP 2003-92179 A Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, conventionally, the graphite electrode is connected to the electrode device by a screwing method, but the screwing method requires high processing costs for graphite, which increases the production costs of the graphite electrode and, in turn, increases the production costs of the quartz crucible.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a graphite electrode that can be used in the same manner as a conventional graphite electrode while reducing processing costs, an electrode device to be connected to such a graphite electrode, and an electrode in which such a graphite electrode is connected to an electrode device. [Means for solving the problem]

[0009] The present invention has been made to solve the above-mentioned problems, and provides a graphite electrode used for arc discharge for manufacturing a quartz crucible, the graphite electrode comprising a graphite electrode body and a connection portion protruding from the graphite electrode body, the graphite electrode being connectable to an electrode device for passing electricity through the graphite electrode via the connection portion, and the connection portion being shaped to be connected to the electrode device by driving in.

[0010] The graphite electrode of the present invention has a connecting portion shaped to be connected to an electrode device by hammering, and therefore is easy to process, and therefore the processing cost can be reduced compared to a conventional graphite electrode having a screw thread. In addition, since the graphite electrode of the present invention can be connected to an electrode device by hammering, it can be used in the same way as a conventional graphite electrode in the actual use scene of manufacturing a quartz crucible.

[0011] In this case, it is preferable that the shape of the connection portion of the graphite electrode is a substantially truncated cone shape in which the diameter of the graphite electrode body side is larger than the diameter of the tip side.

[0012] A graphite electrode having a connection part of this shape is easy to connect to an electrode device.

[0013] It is also preferable that the connection portion has a height of 10 mm or more and 40 mm or less, and has a tapered shape of 1° or more and 5° or less in the height direction.

[0014] A graphite electrode having a connection portion of such dimensions is easy to connect to an electrode device.

[0015] The present invention also provides an electrode device capable of holding the above-mentioned graphite electrode, comprising a hole-shaped holding portion connected to the connection portion of the graphite electrode.

[0016] Such an electrode device is suitable for connection with a graphite electrode as described above.

[0017] In this case, it is preferable that the ratio of the inner diameter of the holding portion to the outer diameter of the electrode device is 40% or more and 60% or less.

[0018] An electrode device having a holding portion of such dimensions can be easily connected to the graphite electrode by hammering, and the electrode device can also easily have an internal structure for flowing a coolant.

[0019] The material of the electrode device preferably contains at least one of gold, silver, copper, and aluminum.

[0020] The material of such an electrode device is a metal that has high malleability and excellent cooling performance, so that it is easy to connect to the graphite electrode by driving in, and is convenient for cooling when used as an electrode.

[0021] The present invention also provides an electrode comprising any one of the graphite electrodes described above and the electrode device.

[0022] In such an electrode, the graphite electrode and the electrode device can be connected by driving in, not by screwing. Since the processing cost of such a graphite electrode can be reduced, the processing cost of the electrode can also be reduced. Effect of the Invention

[0023] The graphite electrode of the present invention has a connecting portion shaped to be connected to an electrode device by driving in, and therefore can be easily processed, and the processing cost can be reduced compared to a conventional graphite electrode having a screw thread. In addition, since the graphite electrode of the present invention can be connected to an electrode device by driving in, it can be used in the same way as a conventional graphite electrode in the actual use scene of manufacturing a quartz crucible. Furthermore, the electrode device of the present invention is suitable for connection to such a graphite electrode. Furthermore, an electrode in which the graphite electrode of the present invention is connected to an electrode device can be one in which the graphite electrode and the electrode device are connected by driving in, not by screwing. Since such a graphite electrode can reduce the processing cost, the processing cost of the electrode can also be reduced. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic diagram showing an example of a graphite electrode, an electrode device, and an electrode in which these are connected together according to the present invention. [Diagram 2] FIG. 1 is a schematic diagram showing an example of a conventional graphite electrode, an electrode device, and an electrode in which these are connected. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The present invention will now be described in more detail.

[0026] The graphite electrode of the present invention is a graphite electrode used for arc discharge for manufacturing a quartz crucible, characterized in that the graphite electrode comprises a graphite electrode body and a connection portion protruding from the graphite electrode body, is connectable to an electrode device for passing electricity through the graphite electrode via the connection portion, and the connection portion is shaped to be connected to the electrode device by driving in.

[0027] Hereinafter, specific embodiments of the graphite electrode, electrode device, and electrode formed by connecting these according to the present invention will be described with reference to the drawings. Fig. 1 shows an embodiment of the graphite electrode, electrode device, and electrode formed by connecting these according to the present invention.

[0028] The graphite electrode 11 shown in Fig. 1(a) comprises a graphite electrode body 12 and a connection part 14 protruding from the graphite electrode body 12. The graphite electrode 11 can be connected to an electrode device (electrode device 21 in Fig. 1(b) described below) for passing electricity through the graphite electrode 11 via the connection part 14. The connection part 14 is shaped to be connected to the electrode device 21 by driving it in. The graphite electrode body 12 can have various external shapes, such as a cylindrical shape.

[0029] 1(b) is capable of holding the graphite electrode 11, and has a hole-shaped holding portion 26 that connects to the connection portion 14 of the graphite electrode 11.

[0030] 1(c) shows an electrode 31 in which the graphite electrode 11 and the electrode device 21 are connected. When making the electrode 31, the connection part 14 of the graphite electrode 11 and the hole-shaped holding part 26 of the electrode device 21 are connected. The graphite electrode 11 and the electrode device 21 are connected by matching the shapes of the connection part 14 and the holding part 26 and hammering them together by an external force.

[0031] Since the graphite electrode 11 of the present invention has the connection part 14 shaped to be connected to the electrode device 21 by driving in, it is easy to process and therefore the processing cost can be reduced compared to a conventional graphite electrode having a thread. Also, since the graphite electrode 11 of the present invention can be connected to the electrode device 21 by driving in, it can be used in the same way as a conventional graphite electrode in the actual use scene of manufacturing a quartz crucible.

[0032] In the present invention, since the connection part 14 of the graphite electrode 11 and the hole-shaped holding part 26 of the electrode device 21 are connected by driving in, due to the necessity of fixing, the inside size of the holding part 26 needs to be slightly larger than the outside size of the connection part 14. However, the shape is not limited as long as the graphite electrode 11 can be fixed by driving in.

[0033] The shape of the connection part 14 of the graphite electrode 11 may be various shapes such as a cylindrical shape, a conical shape, a polygonal prism shape, etc., as long as it can be fixed to the electrode device 21. For example, it may be a cylindrical shape or a tapered truncated cone shape. These shapes are also called nipple shapes, and the connection part 14 having such a shape is also called a nipple. In particular, as shown in FIG. 1(a), it is preferable that the connection part 14 has a substantially truncated cone shape in which the diameter on the graphite electrode body 12 side is larger than the tip side. In particular, it is preferable that the connection part 14 has a height (length) of 10 mm or more and 40 mm or less, and has a tapered shape of 1° or more and 5° or less in the height direction (note that the taper angle is exaggerated in FIG. 1). Such a truncated cone-shaped connection part 14 is easily fixed to the holding part 26 of the electrode device 21 by driving it in.

[0034] On the other hand, it is preferable that the ratio of the inner diameter of the holding portion 26 to the outer diameter of the electrode device 21 is 40% or more and 60% or less. The holding portion 26 having such dimensions is easily fixed to the connection portion 14 of the graphite electrode 11 by hammering.

[0035] In addition, it is preferable that the electrode device 21 is cooled by flowing a coolant such as water inside. This allows the electrode device to have a cooling capacity that can withstand the high temperatures of arc melting. In view of the convenience of the electrode device 21 having a structure in which cooling water flows inside, it is preferable that the ratio of the inner diameter of the holding part 26 to the outer diameter of the electrode device 21 is 40% or more and 60% or less.

[0036] The material of the electrode device 21 preferably contains at least one of gold, silver, copper, and aluminum. These materials are metals with high malleability and high cooling performance, and therefore are preferable because they are easy to connect to the graphite electrode 11 by hammering and easy to cool when used as the electrode 31.

[0037] In addition, in the hole-shaped holding portion 26 of the electrode device 21, the depth of the hole in the holding portion 26 is preferably 10 mm or more and 40 mm or less, similar to the height of the connection portion 14 of the graphite electrode 11. In addition, the tapered shape of the hole in the holding portion 26 is preferably 1° or more and 5° or less in the depth direction, similar to the connection portion 14 of the graphite electrode 11. EXAMPLES

[0038] The present invention will be explained in more detail below by way of examples. However, the present invention is not limited to these examples, and various modifications are possible without departing from the technical concept of the present invention.

[0039] (Examples 1 to 6) A quartz crucible was manufactured using the graphite electrode 11, electrode device 21, and electrode 31 according to the embodiment of the present invention shown in FIG.

[0040] First, a graphite electrode 11 as shown in Fig. 1(a) was prepared. The graphite electrode body 12 was cylindrical with a diameter of 80 mm and a length of 300 mm, and the connection part 14 was approximately frustum-shaped (a protrusion called a nipple). The dimensions of the connection part 14 at this time are as shown in Table 1. In the table, the tip diameter is the diameter of the tip of the connection part 14, the thick part diameter is the diameter at the boundary between the graphite electrode body 12 and the connection part 14, and the middle part diameter is the diameter at the middle of the height (length) from the tip of the connection part 14 to the boundary with the graphite electrode body 12. [Table 1]

[0041] In addition, an electrode device 21 as shown in FIG. 1(b) was prepared.

[0042] Next, as shown in FIG. 1(c), the graphite electrode 11 was connected by a drive-in method via the connection portion 14 and the hole-shaped holding portion 26 to form an electrode 31.

[0043] Next, a quartz crucible (diameter 800 mm, 32 inches) was manufactured by arc discharge using such an electrode 31.

[0044] The quartz crucibles could be manufactured in the same manner as for normal graphite electrodes in all of Examples 1 to 6. Furthermore, the manufacturing cost of the graphite electrodes in Examples 1 to 6 was about half the manufacturing cost of the graphite electrodes having threads.

[0045] This specification includes the following inventions. [1]: A graphite electrode used in arc discharge for producing quartz crucibles, The graphite electrode includes a graphite electrode body and a connection portion protruding from the graphite electrode body, and is connectable to an electrode device for passing electricity through the graphite electrode via the connection portion; A graphite electrode, characterized in that the connection portion is shaped to be connected to the electrode device by hammering. [2]: The graphite electrode according to [1] above, wherein the shape of the connection portion of the graphite electrode is an approximately truncated cone shape in which the diameter of the graphite electrode body side is larger than the diameter of the tip side. [3]: The graphite electrode according to [2] above, wherein the connection portion has a height of 10 mm or more and 40 mm or less and has a tapered shape of 1° or more and 5° or less in the height direction. [4]: An electrode device capable of holding any one of the graphite electrodes described above in [1] to [3], characterized in that the electrode device has a hole-shaped holding portion that connects to the connection portion of the graphite electrode. [5]: The electrode device according to the above [4], wherein the ratio of the inner diameter of the holding portion to the outer diameter of the electrode device is 40% or more and 60% or less. [6]: The electrode device according to [4] or [5] above, wherein the material of the electrode device is at least one of gold, silver, copper and aluminum. [7]: An electrode comprising any one of the graphite electrodes described above in [1] to [3] and the electrode device.

[0046] The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention. [Explanation of symbols]

[0047] 11...graphite electrode; 12...graphite electrode body; 14...connection portion; 21...electrode device, 26...holding part, 31...Electrode.

Claims

1. A graphite electrode used in arc discharge for manufacturing a quartz crucible, The graphite electrode includes a graphite electrode body and a connection portion protruding from the graphite electrode body, and is connectable to an electrode device for passing electricity through the graphite electrode via the connection portion; A graphite electrode, characterized in that the connection portion is shaped to be connected to the electrode device by hammering.

2. 2. The graphite electrode according to claim 1, wherein the shape of the connection portion of the graphite electrode is a substantially truncated cone shape in which the diameter of the graphite electrode body side is larger than that of the tip side.

3. 3. The graphite electrode according to claim 2, wherein the connection portion has a height of 10 mm or more and 40 mm or less, and has a tapered shape of 1° or more and 5° or less in the height direction.

4. 4. An electrode device capable of holding the graphite electrode according to claim 1, further comprising a hole-shaped holding portion connected to the connection portion of the graphite electrode.

5. 5. The electrode device according to claim 4, wherein a ratio of an inner diameter of the holding portion to an outer diameter of the electrode device is 40% or more and 60% or less.

6. 5. The electrode device according to claim 4, wherein the material of the electrode device contains at least one of gold, silver, copper, and aluminum.

7. An electrode comprising the graphite electrode according to any one of claims 1 to 3 and the electrode device.

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