Silicon core wire etching device and silicon core wire etching method

Abstract

The present invention provides a device capable of uniformly etching the entire surface of a silicon core wire. The etching device (1) for etching silicon core wires (C1, C2, C3) comprises: etching liquid tanks (11, 12), the etching liquid tanks (11, 12) contain etching liquids (L1, L2); a plurality of core wire support members (31), the core wire support members (31) are formed with holes (31A) through which the silicon core wires (C1, C2, C3) pass, and support the silicon core wires (C1, C2, C3); and a position changing mechanism (40), the position changing mechanism (40) changes the relative position through which the silicon core wires (C1, C2, C3) pass relative to the holes (31A).

Description

Technical Field

[0001] The invention relates to an etching device for a silicon core wire and an etching method for a silicon core wire. Background Art

[0002] Polycrystalline silicon used for semiconductor materials etc. is required to have very high purity. Patent Document 1 discloses a method for washing polycrystalline silicon in which rod-shaped polycrystalline silicon is washed while being directly suspended from a hanger.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2005-288333 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, even if the above-mentioned prior art is applied to the silicon core wire used for precipitation of polycrystalline silicon, it is difficult to etch the entire surface of the silicon core wire uniformly. In addition, since the silicon core wire is lighter than the rod-shaped polycrystalline silicon, there is a problem that the silicon core wire may fall from the hanger.

[0008] In particular, the hanger described in Patent Document 1 is an L-shaped hanger, so when the silicon core wire, which is the etching object, is supported on the hanger, the upper part of the silicon core wire is largely open. Therefore, there is a problem that the silicon core wire is easy to fall. In order to solve the problem of falling, it is also considered to increase the number of hangers, but if the number of hangers is increased, the number of contact points between the hanger and the etching object increases, so it is difficult to perform uniform etching.

[0009] An object of one aspect of the present invention is to provide a device capable of uniformly etching the entire surface of a silicon core wire.

[0010] Means used to solve problems

[0011] In order to solve the above-mentioned problem, an etching device for silicon core wires according to one form of the present invention comprises: an etching liquid tank, which contains etching liquid for immersing the silicon core wires; a plurality of core wire supporting members, each of which is provided with at least one hole through which the silicon core wire passes and supports the silicon core wires; and a position changing mechanism, which changes the relative position of the silicon core wire with respect to the hole when the silicon core wire passes through the plurality of core wire supporting members and is immersed in the etching liquid.

[0012] A method for etching a silicon core wire according to one aspect of the present invention comprises: a penetration step in which the silicon core wire is penetrated through holes formed in a plurality of core wire support members that support the silicon core wire; a first immersion step in which the silicon core wire supported by the core wire support member is immersed in an etching solution; and a first position change step in which the relative position of the silicon core wire penetrated relative to the hole.

[0013] Effects of the Invention

[0014] According to one aspect of the present invention, it is possible to provide a device capable of uniformly etching the entire surface of a silicon core wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram showing an initial state of the silicon core wire etching device according to the first embodiment of the present invention.

[0016] Figure 2 yes Figure 1 Schematic diagram of the exploded view of the box base and core wire holder of the etching device involved.

[0017] Figure 3 Yes means Figure 1 A diagram showing a state in which a core support plate supports silicon cores in the etching apparatus.

[0018] Figure 4 Yes means Figure 1 A diagram showing a state before the core wire retainer is mounted on a crane in the etching device.

[0019] Figure 5 It means in Figure 4 A diagram showing the crane in question after the core wire retainer is installed.

[0020] Figure 6 This is a flowchart showing a method for etching a silicon core wire using the etching apparatus according to the first embodiment of the present invention.

[0021] Figure 7 Yes means Figure 1 A diagram showing a state in which a silicon core wire is immersed in a first etching solution in the etching apparatus.

[0022] Figure 8 Yes means Figure 1 A diagram showing a state in which a silicon core wire is etched and cleaned in the etching apparatus.

[0023] Fig. 9 It is a schematic exploded view of a box base and a core wire holder of an etching device according to a second embodiment of the present invention.

[0024] Fig.10This is a diagram showing a state before the cassette base is mounted on the crane in the etching apparatus according to the third embodiment of the present invention. DETAILED DESCRIPTION

[0025] [Implementation Method 1]

[0026] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

[0027] 〈Silicon core wire etching equipment〉

[0028] like Figure 1 As shown, the etching apparatus 1 for the silicon core wire C1 includes a first etching liquid tank 11 , a second etching liquid tank 12 , a cleaning tank 13 , a box base 20 , a core wire holder 30 , and a crane (position changing mechanism) 40 .

[0029] In this manual, Figure 1 In the initial state of the etching device 1 shown, the position of the first etching liquid tank 11 relative to the core wire holder 30 is referred to as the front side, and the position of the core wire holder 30 relative to the first etching liquid tank 11 is referred to as the rear side. In addition, the position of the lifting mechanism 43 of the crane 40 relative to the core wire holder 30 is referred to as the upper side, and the position of the core wire holder 30 relative to the lifting mechanism 43 is referred to as the lower side.

[0030] like Figure 2 and Figure 3 As shown, the silicon core wire C1 passes through the through hole 31A of the core wire support plate (core wire support member) 31 of the core wire holder 30 and is supported on the core wire support plate 31. Figure 2 As shown in FIG. 1 and FIG. 2 , in this specification, the right hand side is referred to as the right side and the left hand side is referred to as the left side, facing the front side. The silicon core wire C1 supported by the core wire support plate 31 extends in the left-right direction, so that Figure 1 In the figure, the silicon core wire C1 extends in a direction perpendicular to the paper surface.

[0031] When polycrystalline silicon is manufactured by, for example, the Siemens method, the silicon core wires C1 are used to deposit polycrystalline silicon on the surface of the silicon core wires C1. The silicon core wires C1 are not limited, and are manufactured by, for example, cutting polycrystalline silicon or single crystal silicon in a rod shape.

[0032] The shape of the silicon core wire C1 manufactured in this way is, for example, a cylinder, an elliptical cylinder, a substantially square prism, or a polygonal prism. The prismatic silicon core wire C1 can be easily manufactured by linearly cutting a large rod-shaped polycrystalline silicon. In addition, regarding the size of the silicon core wire C1, for example, the cross-sectional area is 0.1 cm 2 Above, 6cm 2The length is 200 mm or more. The upper limit of the length of the silicon core wire C1 is not particularly limited, but is usually about 2000 mm, preferably about 1500 mm.

[0033] The first etching liquid tank 11 and the second etching liquid tank 12 contain the first etching liquid L1 and the second etching liquid L2 for etching the surface of the silicon core wire C1, respectively. The second etching liquid tank 12 and the washing tank 13 are arranged in sequence on the front side of the first etching liquid tank 11. As described later, in this embodiment, the silicon core wire C1 is immersed in the first etching liquid L1 of the first etching liquid tank 11 for etching, and then immersed in the second etching liquid L2 of the second etching liquid tank 12 for etching.

[0034] The first etching liquid L1 and the second etching liquid L2 are not limited, and for example, a hydrogen fluoride (HF) aqueous solution (also called hydrofluoric acid), a nitric acid (HNO3) aqueous solution, or a mixture thereof can be used. With respect to the silicon core wire C1 after etching, from the viewpoint of improving the flatness of the surface, the second etching liquid L2 preferably has a higher mass ratio of HF to HNO3 than the first etching liquid L1. For example, the mass ratio of HF:HNO3 in the first etching liquid L1 is preferably 1:50 to 1:30, and the mass ratio of HF:HNO3 in the second etching liquid L2 is preferably 1:30 to 1:5.

[0035] In addition, the concentration of HNO3 contained in the first etching liquid L1 and the second etching liquid L2 can be appropriately determined according to the contamination state of the silicon core wire C1 to be etched and the target cleanliness of the silicon core wire C1 after etching. For example, the concentration of HNO3 contained in the first etching liquid L1 is preferably greater than 64 mass% and less than 69 mass%. In addition, the concentration of HNO3 contained in the second etching liquid L2 is preferably greater than 60 mass% and less than 67 mass%. The concentration of HNO3 is preferably higher in the first etching liquid L1 than in the second etching liquid L2, but is not limited to this.

[0036] In this embodiment, two etching tanks are provided as etching tanks, namely, a first etching tank 11 and a second etching tank 12. However, the number of etching tanks is not limited thereto, and one etching tank may be provided, or three or more etching tanks may be provided. Of course, even if the number of etching tanks is one, the present invention can fully exert its effect.

[0037] In the case of setting more than three etching liquid tanks, with respect to the silicon core wire C1 after etching, from the viewpoint of improving the flatness of the surface, the etching liquid contained in the etching liquid tank is preferably a HF mass ratio relative to HNO3 that is high enough to be equivalent to the subsequent process. As a result, it is possible to suppress excessive temperature rise of the etching liquid. The reason is that if the silicon core wire C1 is suddenly etched using an etching liquid with a high HF mass ratio, the etching will proceed rapidly. In addition, in this case, the concentration of HNO3 contained in the third etching liquid is preferably greater than 55 mass% and less than 64 mass%. In addition, the concentration of HNO3 is preferably higher in the second etching liquid L2 than in the third etching liquid.

[0038] The first etching solution tank 11 and the second etching solution tank 12 are preferably formed of at least a material having corrosion resistance to the first etching solution L1 and the second etching solution L2. In addition, the surfaces of the first etching solution tank 11 and the second etching solution tank 12 are preferably formed of a material that does not generate substances that contaminate the silicon core wire C1.

[0039] The washing tank 13 contains washing water L3 for immersing the silicon core wire C1. As the washing water L3, for example, it is preferable to use water with high purity. From the viewpoint of preventing the silicon core wire C1 from being contaminated by impurities, the washing water L3 is preferably pure water with a resistivity of 1 MΩcm (megaohm centimeter) or more. The washing tank 13 can be provided with a plurality of tanks, and the silicon core wire C1 supported by the core wire holder 30 can be immersed in the washing water in each washing tank in turn. In this case, it is preferable to configure it in such a way that the purity of the washing water in the last washing tank is the highest.

[0040] like Figure 2 As shown, the box base 20 includes a frame 21 and eight insertion parts 22. In addition, the number of the insertion parts 22 is not limited to 8, and can be appropriately changed according to the etching efficiency and the size of the etching device 1. The rod-shaped parts included in the frame 21 are respectively configured to correspond to the sides of a substantially rectangular parallelepiped, and the sides extend in the up-down, front-back, or left-right directions.

[0041] The rod-shaped portion extending in the left-right direction of the frame 21 is provided with eight insertion portions 22. The eight insertion portions 22 are shaped in pairs of protrusions facing each other in the left-right direction. The box base 20 is configured as follows: the core wire support plate 31 of the core wire holder 30 described later is inserted between the paired protrusions of the insertion portion 22, and the core wire holder 30 is mounted on the box base 20. In addition, the box base 20 is provided with a fixture (not shown) for fixing the core wire holder 30 to the box base 20.

[0042] The core wire holder 30 includes two core wire support plates 31, a hook 32, and a connection portion 33. The core wire support plates 31 are arranged to extend in the vertical and front-rear directions. The core wire support plates 31 have a plurality of through holes (holes) 31A through which the silicon core wires C1 pass.

[0043] In addition, in the etching device involved in the present invention, if the relative position of the silicon core wire C1 with respect to the through hole 31A can be changed when the silicon core wire C1 passes through the plurality of core wire support plates 31, the box base 20 is not necessary. In the present embodiment, since the core wire holder 30 has the hook 32, the hook 32 is mounted on the crane 40, and the crane 40 reciprocates the core wire holder 30 in the vertical direction, thereby achieving the present invention.

[0044] like Figure 3 As shown, the core support plate 31 is configured to support the silicon core C1 when the silicon core C1 passes through the through hole 31A. Since a plurality of silicon cores C1 can pass through the plurality of through holes 31A formed in the core support plate 31, respectively, the core support plate 31 is configured to support a plurality of silicon cores C1.

[0045] The edge portion of the core wire support plate 31 forming the through hole 31A is formed in a continuous curved shape. In addition, the edge portion of the core wire support plate 31 forming the through hole 31A is preferably a smooth shape without corners. For example, the edge portion of the core wire support plate 31 forming the through hole 31A may be circular or elliptical. Alternatively, the edge portion of the core wire support plate 31 forming the through hole 31A may be, for example, a square, a rectangle, or other polygonal shapes including a quadrilateral and a hexagon.

[0046] Furthermore, when the silicon core wire C1 to be etched is prismatic, the contact area between the silicon core wire C1 and the core wire support plate 31 can be reduced by setting the edge portion of the core wire support plate 31 where the through hole 31A is formed to be circular or elliptical. In this case, when the core wire holder 30 is reciprocated in the up-down direction, the silicon core wire C1 and the core wire support plate 31 are easily separated, so that the relative position where the silicon core wire is inserted can be easily changed, and uniform etching can be easily performed.

[0047] In addition, in order to reduce the contact area with the silicon core wire C1, the edge portion of the core wire support plate 31 where the through hole 31A is formed may be a continuous concave-convex shape. In this case, since the silicon core wire C1 abuts against the front end of the convex portion of the edge portion, it is difficult to abut against the concave portion of the edge portion, so the contact area between the edge portion and the silicon core wire C1 can be easily reduced.

[0048] When the through hole 31A is circular, the diameter of the through hole 31A is preferably 1.1 times or more, and more preferably 1.2 times or more, the diameter of the smallest circle of the cross section of the silicon core wire C1. In addition, the diameter of the through hole 31A is not limited, but is preferably 2.0 times or less of the diameter of the smallest circle of the cross section of the silicon core wire C1. In this case, when the relative position of the silicon core wire C1 passing through is changed with respect to the through hole 31A, the silicon core wire C1 is unlikely to fall off from the core wire support plate 31.

[0049] In addition, when the through hole 31A is a shape other than a circle, the minor diameter of the through hole 31A is preferably 1.1 times or more, and more preferably 1.2 times or more, the diameter of the smallest circle included in the cross section of the silicon core wire C1. In this case, from the viewpoint of preventing the silicon core wire C1 from falling off the core wire support plate 31, the minor diameter of the through hole 31A is preferably 2.0 times or less.

[0050] A portion of the edge portion of the core support plate 31 forming the through hole 31A may be opened to a length shorter than the diameter of the smallest circle containing the cross section of the silicon core wire. However, in order to prevent the silicon core wire C1 from falling off the core support plate 31 during etching and / or washing, the edge portion of the core support plate 31 forming the through hole 31A is preferably set to a continuous shape. In addition, when the edge portion of the core support plate 31 forming the through hole 31A is a continuous shape, since a plurality of through holes can be easily arranged on the core support plate 31, it is easy to etch a plurality of silicon core wires C1 simultaneously.

[0051] like Figure 4 and Figure 5 As shown, the hook 32 extends outward from the upper surface of the core wire support plate 31 in the left-right direction and is installed on the arm 41 of the crane 40. Figure 4 as well as Figure 5 In the figure, the silicon core C1 to be supported by the core holder 30 is omitted and shown. The crane 40 supports the core holder 30 by installing the hook 32 on the arm 41. As a result, the core holder 30 can be moved in the up-down direction or the front-back direction. In the case where the core holder 30 is installed on the box base 20 using a fixture, the box base 20 and the core holder 30 can be moved in the up-down direction or the front-back direction as a whole. Figure 2 The connecting portion 33 shown extends in the left-right direction so as to connect the two core wire supporting plates 31 to each other.

[0052] In the first etching liquid L1 or the second etching liquid L2 or the washing water L3, by moving the core wire holder 30 in the up-down direction or the front-back direction, the relative position of the silicon core wire C1 passing through with respect to the through hole 31A can be changed. In addition, in this specification, "changing the relative position of the silicon core wire C1 passing through with respect to the through hole 31A" includes: changing the position of the silicon core wire C1 contacting the edge portion of the core wire support plate 31 forming the through hole 31A.

[0053] In addition, when the relative position of the silicon core C1 to be passed through is changed with respect to the through hole 31A, in order to uniformly etch the entire surface of the silicon core C1, it is preferable that the edge portion of the core support plate 31 where the through hole 31A is formed is temporarily separated from the silicon core C1. Here, as described later, by reciprocating the core holder 30 in the up-down direction, the core support plate 31 is reciprocated in the up-down direction, so that the silicon core C1 is easily separated from the core support plate 31 when the core support plate 31 starts to descend after rising. Therefore, when etching or washing the silicon core C1, it is preferable to reciprocate the core holder 30 supporting the silicon core C1 in the up-down direction.

[0054] In this embodiment, the hook 32 is arranged on the two core wire support plates 31. However, the present invention is not limited to this, and the hook may be arranged at a location corresponding to the center of the box base 20, or may be arranged at three or more locations. However, when the integrated box base 20 and the core wire holder 30 are moved by the crane 40, the hook 32 is preferably installed in a manner that the connecting portion 33 can maintain a substantially horizontal state. Therefore, the hook 32 is preferably as follows: Figure 2 As shown, they are respectively arranged on two core wire supporting plates 31.

[0055] like Figure 1 As shown, the crane 40 includes an arm 41, a wire rope 42, a lifting mechanism 43, a trolley 44, and a track 45. The arm 41 is configured to be retractable in the left-right direction. When the hook 32 is mounted on the arm 41, first, as shown in FIG. Figure 4 As shown in FIG. 4 , the arm 41 is arranged above the cartridge base 20 and the arm 41 is extended in the left-right direction. Figure 5 As shown, using the lifting mechanism 43 (shown in Figure 1 ) The arm 41 is lowered and the arm 41 is contracted in the left-right direction, thereby enabling the hook 32 to be installed on the arm 41.

[0056] like Figure 1As shown, the wire rope 42 connects the arm 41 to the lifting mechanism 43. The lifting mechanism 43 raises and lowers the arm 41 by winding or releasing the wire rope, for example. The trolley 44 is connected to the lifting mechanism 43 in a movable manner relative to the track 45. The track 45 guides the trolley 44 in the front-to-back direction. The track 45 extends in the front-to-back direction above the first etching liquid tank 11, the second etching liquid tank 12 and the washing tank 13. The arm 41, the lifting mechanism 43 and the trolley 44 are connected to a control unit (not shown), and the extension and extension and lifting of the arm 41 and the movement of the trolley 44 are controlled by the control unit.

[0057] 〈Silicon Core Wire Etching Method〉

[0058] use Figure 1 as well as Figure 6 to Figure 8 , a method for etching the silicon core wire C1 is described.

[0059] like Figure 6 As shown, first, the silicon core wire C1 is passed through the through hole 31A of the two core wire support plates 31, and the two core wire support plates 31 are used to support the silicon core wire C1 (S1: passing step). In S1, in order to prevent the silicon core wire C1 from falling off the core wire support plates 31 during etching, it is preferred that both ends of the silicon core wire C1 are respectively arranged on the left and right sides of the two core wire support plates 31. The length of the silicon core wire C1 protruding on the left and right sides of the two core wire support plates 31 is not particularly limited as long as it can prevent the silicon core wire C1 from falling off. The length of the silicon core wire C1 protruding on the left and right sides of the two core wire support plates 31 is, for example, preferably not less than 1% and not more than 15% of the length of the silicon core wire C1, and more preferably not less than 3% and not more than 10%.

[0060] Then, the core wire holder 30 is mounted on the box base 20 by inserting the core wire support plate 31 into the insertion portion 22 (S2). In this state, the core wire holder 30 is fixed to the box base 20 by a fixture (not shown) of the box base 20.

[0061] Next, the hook 32 is mounted on the arm 41. Figure 1 From the initial state of the etching apparatus 1 shown in FIG. 1 , the core wire holder 30 mounted on the box base 20 is raised by the lifting mechanism 43. Then, the carriage 44 is moved forward along the rail 45 to place the core wire holder 30 mounted on the box base 20 above the first etching liquid tank 11. From this state, the core wire holder 30 mounted on the box base 20 is lowered by the lifting mechanism 43, thereby, as shown in FIG. Figure 7 As shown, the silicon core wires C1 supported on the core wire support plate 31 are immersed in the first etching liquid L1 (S3: first immersion step).

[0062] As described above, in a state where the silicon core wire C1 is immersed in the first etching liquid L1, the core wire holder 30 is reciprocated in the vertical direction, thereby changing the relative position of the silicon core wire C1 with respect to the through hole 31A (S4: first position changing process). In addition, the speed of reciprocating the core wire holder 30 can be appropriately determined according to the etching device 1 and the shape and size of the silicon core wire C1, and is preferably a speed at which the silicon core wire C1 is not damaged by contact with the core wire support plate 31. The speed of changing the relative position of the silicon core wire C1 with respect to the through hole 31A is preferably, for example, more than 30 times and less than 90 times per minute. In particular, the speed of reciprocating the core wire holder 30 in the vertical direction is preferably more than 30 times and less than 90 times per minute.

[0063] In S4, since the contact portion of the surface of the silicon core wire C1 with the core wire support plate 31 changes as the core wire holder 30 reciprocates, the entire surface of the silicon core wire C1 can contact the first etching liquid L1. Therefore, the entire surface of the silicon core wire C1 can be uniformly etched. In addition, since the silicon core wire C1 is supported on the core wire support plate 31 while penetrating the through hole 31A formed in the core wire support plate 31, the silicon core wire C1 can be prevented from falling from the core wire support plate 31.

[0064] In addition, by reciprocating the core wire holder 30 in the vertical direction, the core wire support plate 31 reciprocates in the vertical direction, so that when the core wire support plate 31 starts to descend after rising, the silicon core wire C1 is easily separated from the core wire support plate 31. Therefore, during etching, the entire surface of the silicon core wire C1 is more likely to contact the first etching liquid L1, so the entire surface of the silicon core wire C1 can be etched more uniformly. In addition, since the core wire holder 30 does not need to move in the horizontal direction, the horizontal dimension of the etching device 1 can be reduced, so the etching device 1 can be miniaturized.

[0065] In addition, the edge portion of the core wire support plate 31 where the through hole 31A is formed is preferably formed in a continuous curved shape. In this case, since the contact area between the silicon core wire C1 and the core wire support plate 31 is easily reduced, the silicon core wire C1 is easily separated from the core wire support plate 31. In addition, since the edge portion of the core wire support plate 31 where the through hole 31A is formed is continuous, the silicon core wire C1 can be prevented from falling from the core wire support plate 31. As a result, the entire surface of the silicon core wire C1 can be etched more uniformly while the silicon core wire C1 is stably supported on the core wire support plate 31.

[0066] In addition, since the core support plate 31 has a plurality of through holes 31A, the core support plate 31 can support a plurality of silicon cores C1. Therefore, the plurality of silicon cores C1 can be etched efficiently.

[0067] Next, after etching the silicon core wire C1 with the first etching liquid L1, the core wire holder 30 mounted on the box base 20 is raised by the lifting mechanism 43, thereby taking out the silicon core wire C1 from the first etching liquid L1 (S5). Then, the carriage 44 is moved forward along the rail 45, and the core wire holder 30 mounted on the box base 20 is arranged above the second etching liquid tank 12.

[0068] Then, in the same manner as S3 to S5, the silicon core wire C1 is immersed in the second etching solution L2 (S6: first immersion step), the core wire holder 30 is reciprocated in the vertical direction (S7: first position change step), and the silicon core wire C1 is taken out from the second etching solution L2 (S8).

[0069] Then, the carriage 44 is moved forward along the rail 45, and the core wire holder 30 mounted on the box base 20 is arranged above the washing tank 13. Then, in the same manner as S3 to S5, the silicon core wire C1 is immersed in the washing water L3 (S9: second immersion process), the core wire holder 30 is reciprocated in the vertical direction (S10: second position change process), and the silicon core wire C1 is taken out from the washing water L3 (S11).

[0070] In S10, since the contact position of the surface of the silicon core wire C1 with the core wire support plate 31 changes with the reciprocating movement of the core wire holder 30, the entire surface of the silicon core wire C1 can contact the washing water L3, so that the entire surface of the silicon core wire C1 can be evenly washed.

[0071] Then, the trolley 44 is moved along the track 45 to the front of the washing tank 13. Figure 8 As shown, the core wire holder 30 mounted on the box base 20 is lowered by the lifting mechanism 43. After the hook 32 is removed from the arm 41 and the core wire holder 30 is removed from the box base 20, the silicon core wire C1 is extracted from the two core wire support plates 31, thereby obtaining the etched silicon core wire C1.

[0072] 〈Variation Example〉

[0073] In this embodiment, the box base 20 has an insertion portion 22 having a pair of protrusions, and the core wire support plate 31 is inserted between the pair of protrusions of the insertion portion 22. However, the present invention is not limited to this, and a groove for inserting the core wire support plate 31 may be formed on the box base 20 instead of the insertion portion 22 having a protrusion shape.

[0074] In addition, in the present embodiment, after the silicon core wire C1 is passed through the through hole 31A of the core wire support plate 31, the core wire holder 30 is mounted on the box base 20. However, the present invention is not limited to this, and the silicon core wire C1 may be passed through the through hole 31A of the core wire support plate 31 after the core wire holder 30 is mounted on the box base 20.

[0075] In addition, in the present embodiment, the relative position of the silicon core wire C1 passing through is changed with respect to the through hole 31A by reciprocating the integrated box base 20 and the core wire holder 30 in the vertical direction. However, the present invention is not limited thereto, and the relative position of the silicon core wire C1 passing through is changed with respect to the through hole 31A by, for example, reciprocating the first etching liquid tank 11, the second etching liquid tank 12, or the washing tank 13 in the vertical direction.

[0076] Alternatively, a forced circulation flow may be formed in the first etching liquid L1, the second etching liquid L2 or the washing water L3, and the forced circulation flow may be directed toward the silicon core wire C1, thereby changing the relative position of the silicon core wire C1 with respect to the through hole 31A. The forced circulation flow may also be formed by providing a spray nozzle in the first etching liquid tank 11, the second etching liquid tank 12 or the washing tank 13, and spraying the circulating liquid from the spray nozzle.

[0077] [Implementation Method 2]

[0078] Other embodiments of the present invention are described below. In addition, for the sake of convenience, components having the same functions as those described in the above embodiments are denoted by the same reference numerals, and their descriptions are not repeated. Fig. 9 As shown, the difference between Embodiment 2 and Embodiment 1 is that a short core wire retainer 70 and a middle core wire retainer 80 are installed on the box base 60 .

[0079] The short core wire holder 70 includes two core wire support plates 31, a hook 32, and a connecting portion 73. The length of the connecting portion 73 in the left-right direction is Figure 2 The length of the connecting portion 33 shown in the figure in the left-right direction is short. Therefore, the short core wire holder 70 is suitable for supporting the short silicon core wire C2 whose length in the left-right direction is shorter than that of the silicon core wire C1.

[0080] in addition, Fig. 9 The middle core wire holder 80 shown in the figure comprises: two core wire support plates 31, hooks 32, and a connecting portion 83. The length of the connecting portion 83 in the left-right direction is longer than the length of the connecting portion 73 in the left-right direction, and is longer than Figure 2 The length of the connecting portion 33 shown in the figure is short in the left-right direction. Therefore, the middle core wire holder 80 is suitable for supporting the middle silicon core wire C3 which is longer in the left-right direction than the short silicon core wire C2 and shorter in the left-right direction than the silicon core wire C1. Fig. 9 In the figure, the short core wire holder 70 and the middle core wire holder 80 support one short silicon core wire C2 and one middle silicon core wire C3 respectively, but may also support a plurality of them.

[0081] like Fig. 9 As shown, the box base 60 includes: a frame 21, 8 short strip insertion parts 62, and 8 middle strip insertion parts 63. The 8 short strip insertion parts 62 and 8 middle strip insertion parts 63 are provided on a rod-shaped part extending in the left-right direction provided on the frame 21. The 8 short strip insertion parts 62 and the 8 middle strip insertion parts 63 are in the shape of a pair of protrusions facing each other in the left-right direction.

[0082] The left and right positions of the eight short-bar insertion portions 62 correspond to the positions of the two core wire support plates 31 of the short-bar core wire retainer 70. In addition, the left and right positions of the eight middle-bar insertion portions 63 correspond to the positions of the two core wire support plates 31 of the middle-bar core wire retainer 80.

[0083] Fig. 9 In the embodiment, since the etching device 1 includes the short core wire holder 70 and the middle core wire holder 80, the hooks 32 of each of them are four in total. When both the short core wire holder 70 and the middle core wire holder 80 are fixed to the box base 60, as long as the short core wire holder 70 and the middle core wire holder 80 are kept in a substantially horizontal state, the hook 32 of each of the short core wire holder 70 and the middle core wire holder 80 can be mounted on the arm 41 of the crane 40 (shown in FIG. Figure 4 Alternatively, a crane 40 having four arms 41 may be prepared, and the arms 41 may be installed on all four hooks 32.

[0084] When polysilicon is manufactured by the Siemens method, the upper parts of two long silicon core wires standing in a substantially vertical direction are connected by a short silicon core wire C2, and the two long silicon core wires and the short silicon core wire C2 are electrically heated as a whole. In addition, the long silicon core wire is manufactured by, for example, fusing the short silicon core wire C2 and the middle silicon core wire C3, which are shorter than the short silicon core wire C2.

[0085] According to the above configuration, the short core wire holder 70 or the middle core wire holder 80 can be selected according to the length of the short core wires C2 or the middle core wires C3. Therefore, the core wire support plate 31 can reliably support the core wires C2 and C3 regardless of the length of the core wires C2 and C3.

[0086] 〈Variation Example〉

[0087] In this embodiment, the box base 20 has: 8 short strip insertion parts 62, and 8 medium strip insertion parts 63. However, the present invention is not limited to this, and a total of more than 16 insertion parts can be provided at different positions in the left-right direction on the box base 20. In this case, by changing the position of the insertion part into which the core wire support plate 31 is inserted, the distance between the two core wire support plates 31 can be changed more finely. Therefore, since the distance between the two core wire support plates 31 can be changed more finely according to the length of the silicon core wire C1, the core wire support plate 31 can more reliably support the silicon core wires C2 and C3 regardless of the length of the silicon core wires C2 and C3.

[0088] [Implementation method 3]

[0089] like Fig.10 As shown, the difference between the third embodiment and the first embodiment is that the box base 20 is provided with a detachable hook 233 instead of the core wire retainer 30. In addition, for the convenience of description, the same symbols are attached to the components having the same functions as those described in the previous embodiments, and their descriptions are not repeated. Fig.10 In FIG. 1 , the silicon core wire C1 to be supported by the core wire holder 30 is omitted and shown.

[0090] The box base 20 has two fixtures 23 for fixing the core wire holder 30 to the box base 20. The two fixtures 23 are separated in the left-right direction. The two fixtures 23 respectively have: two mounting parts 231, a connecting part 232, and a hook 233. The two mounting parts 231 are arranged in a manner facing each other in the front-back direction, and are configured to be detachably mounted on the upper side of the rod-shaped part extending in the left-right direction of the frame 21. By mounting the mounting part 231 on the frame 21 or removing it from the frame 21, the fixture 23 can be mounted on the frame 21 or removed from the frame 21. In this case, etching and washing of the silicon core wire C1 are performed in a state where the core wire holder 30 is fixed to the box base 20.

[0091] The connection part 232 is a plate-shaped member that connects two mounting parts 231 that face each other in the front-rear direction. The hook 233 extends outward in the left-right direction from the upper surface of the connection part 232 and is configured to be mounted on the arm 41 of the crane 40 .

[0092] When etching the silicon core wire C1, first, with the fixture 23 removed from the frame 21, the two core wire support plates 31 supporting the silicon core wire C1 are inserted into the insertion portion 22. Then, the fixture 23 is mounted on the frame 21, and the core wire holder 30 is fixed to the box base 20. Then, the hook 233 of the box base 20 is mounted on the arm 41. The subsequent process is the same as that of the first embodiment.

[0093] As described above, when the box base 20 is configured to include the detachable hook 233, the position of the hook 233 can be easily adjusted by, for example, changing the position of the fixture 23. Therefore, when the box base 20 is moved up and down by the crane 40, it is also easy to keep the rod-shaped portion extending in the front-back direction and the left-right direction of the box base 20 substantially horizontal.

[0094] 〈Variation Example〉

[0095] Regarding the third embodiment, similar to the second embodiment, the short core wire holder 70 and the middle core wire holder 80 may be mounted on the box base 60 and fixed by the fixture 23. In this case, the position of the hook 233 can be easily adjusted by changing the position of the fixture 23. Therefore, when the box base 20 is moved up and down by the crane 40, it is also easy to keep the rod-shaped portion extending in the front-back direction and the left-right direction of the box base 20 substantially horizontal. In addition, since one box base 20 has two hooks 233, the crane 40 only needs to have two arms 41, and there is no need to make the etching device 1 a complicated structure.

[0096] [Summarize]

[0097] An etching device for silicon core wires according to one form of the present invention comprises: an etching liquid tank, which contains etching liquid for immersing the silicon core wires; a plurality of core wire supporting members, each of which is provided with at least one hole through which the silicon core wire passes and supports the silicon core wires; and a position changing mechanism, which changes the relative position of the silicon core wire with respect to the hole when the silicon core wire passes through the plurality of core wire supporting members and is immersed in the etching liquid.

[0098] In addition, in this specification, a "hole" includes not only a hole whose edge portion forming the hole is continuous, that is, a closed shape, but also a hole whose edge portion forming the hole is open to a length shorter than the diameter of the smallest circle included in the cross section of the silicon core wire. Therefore, a part of the edge portion forming the hole in the core wire support member may be open to a length shorter than the diameter of the smallest circle included in the cross section of the silicon core wire.

[0099] According to the above configuration, when the silicon core wire passes through a plurality of core wire support members and is immersed in an etching solution, the relative position of the silicon core wire passing through the hole is changed by the position changing mechanism, thereby changing the contact portion of the surface of the silicon core wire with the core wire support member. Therefore, during etching, the entire surface of the silicon core wire can contact the etching solution, so that the entire surface of the silicon core wire can be uniformly etched. In addition, since the silicon core wire is supported on the core wire support member while passing through the hole formed on the core wire support member, it is possible to prevent the silicon core wire from falling off the core wire support member.

[0100] In the silicon core wire etching device according to one embodiment of the present invention, the position changing mechanism can also reciprocate the core wire support member in the up-down direction. According to the configuration, since the core wire support member reciprocates in the up-down direction, the silicon core wire is easily separated from the core wire support member when the core wire support member starts to descend after rising. Therefore, during etching, since the entire surface of the silicon core wire is more easily in contact with the etching liquid, the entire surface of the silicon core wire can be etched more uniformly. In addition, since the core wire support member does not need to move in the horizontal direction, the horizontal dimension of the etching device can be reduced, so the etching device can be miniaturized.

[0101] In the silicon core wire etching device according to one embodiment of the present invention, the edge portion forming the hole can also be formed into a continuous curved shape. According to the above configuration, since the contact area between the silicon core wire and the core wire support member is easily reduced, the silicon core wire is easily separated from the core wire support member. In addition, since the edge portion forming the hole is continuous, that is, closed, it is possible to prevent the silicon core wire from falling off the core wire support member. As a result, the entire surface of the silicon core wire can be etched more uniformly while the silicon core wire is stably supported on the core wire support member.

[0102] In the silicon core wire etching device according to one aspect of the present invention, the silicon core wires are respectively passed through the holes formed in at least two of the core wire support members included in the plurality of core wire support members, and the distance between the two core wire support members can be changed according to the length of the silicon core wire. According to the above configuration, the core wire support member can reliably support the silicon core wire regardless of the length of the silicon core wire.

[0103] In the silicon core etching device according to one aspect of the present invention, a plurality of holes may be formed in the core support member. According to the configuration, since the core support member can support a plurality of silicon cores, the plurality of silicon cores can be etched efficiently.

[0104] The silicon core wire etching device involved in one form of the present invention also has a washing tank, which contains washing water for immersing the silicon core wire. The position changing mechanism can change the relative position of the silicon core wire with respect to the hole when the silicon core wire immersed in the etching solution passes through the multiple core wire supporting members and is immersed in the washing water.

[0105] According to the above configuration, when the silicon core wire is inserted through the plurality of core wire support members and immersed in the washing water, the position changing mechanism changes the relative position of the silicon core wire with respect to the hole, thereby changing the contact portion of the surface of the silicon core wire with the core wire support member. Therefore, during washing, the entire surface of the silicon core wire can be in contact with the washing water, so that the entire surface of the silicon core wire can be uniformly washed.

[0106] A method for etching a silicon core wire according to one aspect of the present invention comprises: a penetration step in which the silicon core wire is penetrated through holes formed in a plurality of core wire support members that support the silicon core wire; a first immersion step in which the silicon core wire supported by the core wire support member is immersed in an etching solution; and a first position change step in which the relative position of the silicon core wire penetrated relative to the hole.

[0107] The etching method of a silicon core wire involved in one form of the present invention may also include: a second immersion step, which immerses the silicon core wire supported by the core wire supporting member in washing water after the first position changing step; and a second position changing step, which changes the relative position of the silicon core wire immersed in the washing water with respect to the hole.

[0108] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0109] Example

[0110] An embodiment of the present invention is described below.

[0111] [Example 1]

[0112] 〈Preparation of Silicon Core Wire C1〉

[0113] As the silicon core wires C1 used in this example, nine prismatic silicon core wires C1 were prepared, each having a 10 mm square cross-sectional shape perpendicular to the extending direction and a length of 1200 mm in the extending direction.

[0114] <Preparation of the core wire retainer 30>

[0115] As Figure 2As shown in the core wire support plate 31, two core wire support plates 31 with a thickness of 10 mm are prepared, and nine circular through holes 31A with a diameter of 20 mm are formed in an evenly arranged manner. The core wire support plates 31 are arranged at a distance of 1 m in the left-right direction so that the positions of the nine through holes 31A are arranged at the same positions in the up-down direction and the front-back direction. Then, as Figure 2 As shown in FIG. 1 , the core wire holder 30 is prepared by attaching the connecting portion 33 and the hook 32 to the core wire support plate 31 .

[0116] <Arrangement of Silicon Core Wire C1 in Core Wire Holder 30: Penetration Process>

[0117] Next, two through holes 31A arranged at the same position in the vertical direction and the front-back direction in the two core wire support plates 31 are regarded as one group, and one silicon core wire C1 is inserted into each of the nine groups of through holes 31A. At this time, each silicon core wire C1 is arranged on the core wire holder 30 in a state where both ends thereof protrude about 100 mm outward in the left-right direction from the core wire support plate 31.

[0118] <Installation of the core wire holder 30 on the box base 20>

[0119] The core wire holder 30 supporting the silicon core wire C1 is installed in the box base 20 by inserting the core wire support plate 31 into the insertion portion 22 of the box base 20. Figure 2 In this state, the core wire holder 30 is fixed to the box base 20 by a fixture (not shown) of the box base 20, so that the core wire holder 30 and the box base 20 are integrated.

[0120] <Etching: First Immersion Step and First Position Changing Step>

[0121] like Figure 4 and Figure 5 As shown, in order to enable the integrated box base 20 and the core wire holder 30 to be moved in the vertical direction and the front-rear direction by the crane 40 , the hook 32 of the core wire holder 30 is mounted on the arm 41 of the crane 40 .

[0122] Secondly, if Figure 7As shown, the integrated box base 20 and the core wire holder 30 are moved by the crane 40, and the core wire holder 30 and the box base 20 are immersed in the first etching liquid L1 contained in the first etching liquid tank 11 (first immersion process). In addition, the first etching liquid L1 is set to an aqueous solution containing 67 mass% HNO3 and 2 mass% HF. Then, the integrated box base 20 and the core wire holder 30 are reciprocated in the vertical direction at a speed of 40 times per minute for 5 minutes. At this time, it is visually confirmed that the relative position of the silicon core wire C1 passed through relative to the through hole 31A has changed (first position change process).

[0123] Then, the integrated box base 20 and the core wire holder 30 are lifted by using the crane 40, so that the integrated box base 20 and the core wire holder 30 are taken out of the first etching liquid L1. Then, the integrated box base 20 and the core wire holder 30 are moved by using the crane 40, so that the core wire holder 30 supporting the silicon core wire C1 and the entire box base 20 are immersed in the second etching liquid L2 contained in the second etching liquid tank 12 (first immersion process). In addition, the second etching liquid L2 is set to an aqueous solution containing 64 mass% HNO3 and 4 mass% HF. Then, the integrated box base 20 and the core wire holder 30 are reciprocated in the up and down direction at a speed of 40 times per minute for 10 minutes. At this time, it is visually confirmed that the relative position of the silicon core wire C1 is changed relative to the through hole 31A (first position change process).

[0124] <Washing: Second Immersion Step and Second Position Changing Step>

[0125] Next, the integrated box base 20 and the core wire holder 30 are lifted by using the crane 40, thereby taking the integrated box base 20 and the core wire holder 30 out of the second etching liquid L2. Then, the integrated box base 20 and the core wire holder 30 are moved by using the crane 40, so that the core wire holder 30 supporting the silicon core wire C1 and the entire box base 20 are immersed in the washing water L3 contained in the washing tank 13 (second immersion process). In addition, the washing water L3 is set to pure water with a resistivity of 2MΩcm. Then, the integrated box base 20 and the core wire holder 30 are reciprocated in the up and down directions at a speed of 40 times per minute for 2 minutes. At this time, it is visually confirmed that the relative position through which the silicon core wire C1 passes is changed relative to the through hole 31A (second position change process)

[0126] <dry>

[0127] Then, the integrated box base 20 and the core holder 30 are taken out from the washing tank 13, and the excess washing water L3 attached to the core holder 30 and the box base 20 is removed. Then, the silicon core C1 together with the core holder 30 and the box base 20 are dried.

[0128] 〈Evaluation and Observation〉

[0129] After drying, the obtained 9 silicon core wires C1 were visually observed. All the 9 silicon core wires C1 had uniform surfaces and metallic luster, indicating no uneven etching. In addition, all the 9 silicon core wires C1 passed the etching process and the washing process without falling off the core wire holder 30 .

[0130] [Comparative Example 1]

[0131] The same treatment as in Example 1 was performed except that the integrated box base 20 and the core wire holder 30 were immersed in a stationary state instead of being reciprocated in the vertical direction in the "etching" and "cleaning" of Example 1. The immersion time was 5 minutes in the first etching liquid L1, 10 minutes in the second etching liquid L2, and 2 minutes in the washing water L3.

[0132] After drying, the obtained 9 silicon core wires C1 were visually observed. In all the 9 silicon core wires C1, the portion where the silicon core wire C1 contacts the edge portion where the through hole 31A is formed in the core support plate 31 and the vicinity thereof have a gloss different from other portions, and it can be seen that etching unevenness is obviously generated. In addition, in this specification, the portion where the silicon core wire C1 contacts the edge portion where the through hole 31A is formed in the core support plate 31 is referred to as the contact portion of the silicon core wire C1 with the core support plate 31.

[0133] [Comparative Example 2]

[0134] The same treatment as in Example 1 was performed except that the integrated box base 20 and the core wire holder 30 were not reciprocated in the vertical direction in the "etching" of Example 1, but were immersed in a stationary state. In addition, the difference from Comparative Example 1 is that in the "washing: second immersion step and second position change step", the integrated box base 20 and the core wire holder 30 were reciprocated in the vertical direction at a speed of 40 times per minute for 2 minutes.

[0135] After drying, the obtained 9 silicon core wires C1 were visually observed. All the 9 silicon core wires C1 had a different gloss at the contact part with the core wire support plate 31 and the vicinity thereof from other parts, indicating that etching unevenness occurred significantly. Therefore, it is shown that, when the box base 20 and the core wire holder 30 are not reciprocated during the etching process, even if the relative position of the silicon core wire C1 is changed during the washing process, etching unevenness cannot be eliminated.

[0136] [Example 2]

[0137] The same process as in Example 1 was performed except that two core wire support plates 31 having a thickness of 10 mm and having nine square through holes 31A each having a side of 20 mm formed in an evenly arranged manner were used as the core wire holder 30 .

[0138] After drying, the obtained 9 silicon core wires C1 were visually observed. The surfaces of 5 of the silicon core wires C1 were uniform and metallic in appearance, indicating that there was no etching unevenness. In addition, the remaining 4 silicon core wires C1 had a slightly different luster from other parts at the contact part with the core wire support plate 31 and its vicinity in the silicon core wire C1, indicating that a little etching unevenness occurred. However, the etching unevenness observed in Example 2 was shallower than the etching unevenness in Comparative Examples 1 and 2, and was difficult to distinguish and was not likely to become a major problem.

[0139] [Example 3]

[0140] The same process as in Example 2 was performed except that the speed of the reciprocating movement of the integrated box base 20 and the core wire holder 30 in "Etching" was set to 80 times per minute. Specifically, the integrated box base 20 and the core wire holder 30 were reciprocated in the vertical direction at a speed of 80 times per minute for 5 minutes while the silicon core wire C1 was immersed in the first etching liquid L1. In addition, the integrated box base 20 and the core wire holder 30 were reciprocated in the vertical direction at a speed of 80 times per minute for 10 minutes while the silicon core wire C1 was immersed in the second etching liquid L2.

[0141] After drying, the obtained nine silicon core wires C1 were visually observed. All of the nine silicon core wires C1 had uniform surfaces as a whole and had metallic luster, and it was found that there was no etching unevenness.

[0142] [Example 4]

[0143] The same process as in Example 1 was performed except that two core wire support plates 31 having a thickness of 10 mm and having nine regular hexagonal through holes 31A inscribed in a circle with a diameter of 20 mm were formed in an evenly arranged manner were used as the core wire holder 30 .

[0144] After drying, the obtained 9 silicon core wires C1 were visually observed. The surfaces of 7 of the silicon core wires C1 were uniform and metallic in appearance, indicating that there was no etching unevenness. In addition, the remaining 2 silicon core wires C1 had a slightly different luster from other parts at the contact part with the core wire support plate 31 and the vicinity thereof in the silicon core wire C1, indicating that a little etching unevenness occurred. However, the etching unevenness observed in Example 4 was shallower than the etching unevenness in Comparative Examples 1 and 2, and was difficult to distinguish and was not likely to become a major problem.

[0145] [Example 5]

[0146] The same process as in Example 4 was performed except that the speed of the reciprocating movement of the integrated box base 20 and the core wire holder 30 in "Etching" was set to 60 times per minute. Specifically, the integrated box base 20 and the core wire holder 30 were reciprocated in the vertical direction at a speed of 60 times per minute for 5 minutes while the silicon core wire C1 was immersed in the first etching liquid L1. In addition, the integrated box base 20 and the core wire holder 30 were reciprocated in the vertical direction at a speed of 60 times per minute for 10 minutes while the silicon core wire C1 was immersed in the second etching liquid L2.

[0147] After drying, the obtained nine silicon core wires C1 were visually observed. All of the nine silicon core wires C1 had uniform surfaces as a whole and had metallic luster, and it was found that there was no etching unevenness.

[0148] Comparison between Examples 1, 2, and 4 shows that the shape of the edge portion forming the through hole 31A in the core support plate 31 is preferably a smooth curve without corners, as in the circular shape shown in Example 1. In addition, comparison between Examples 2 and 4 shows that the closer the shape of the edge portion forming the through hole 31A in the core support plate 31 is to a circle, the more uniformly the entire surface of the silicon core C1 can be etched even if the moving speed in the up-down direction is low.

[0149] Comparison between Examples 2 and 3 and between Examples 4 and 5 shows that even when the edge portion of the core support plate 31 forming the through hole 31A is not curved, etching uniformity can be improved by increasing the reciprocating speed of the core holder 30 .

[0150] Explanation of symbols

[0151] 1 Etching device

[0152] 11. First etching tank (etching tank)

[0153] 12. Second etching tank (etching tank)

[0154] 13 Sink

[0155] 20, 60 box base

[0156] 22 Insertion

[0157] 30 core wire retainer

[0158] 31 Core support plate (core support member)

[0159] 31A Through hole (hole)

[0160] 33, 73, 83 Connection

[0161] 40 Crane (position changing mechanism)

[0162] 41 Arm

[0163] 43 Lifting mechanism

[0164] 62 Short strip insertion part

[0165] 63 Middle strip insertion part

[0166] 70 Short core wire retainer

[0167] 80 middle core wire retainer

[0168] C1 Silicon Core Wire

[0169] C2 short silicon core wire (silicon core wire)

[0170] C3 Middle Strip Silicon Core Wire (Silicon Core Wire)

[0171] L1 First etching solution (etching solution)

[0172] L2 Second etching liquid (etching liquid)

[0173] L3 Washing water

[0174] S1 Through-process

[0175] S3, S6 First dipping step

[0176] S4, S7 First position change process

[0177] S9 Second dipping process

[0178] S10 Second position changing process

Claims

1. A silicon core wire etching device, characterized in that: have: An etching liquid tank, the etching liquid tank containing etching liquid for dipping the silicon core wire; A plurality of core wire support members, each core wire support member having at least one hole through which the silicon core wire passes in the left-right direction and supporting the silicon core wire in the left-right direction; a position changing mechanism that reciprocates the plurality of core wire support members in the up-down direction, so that the relative position of the silicon core wire passing through the plurality of core wire support members in the left-right direction is changed relative to the hole in a state where the silicon core wire passes through the plurality of core wire support members in the left-right direction and is immersed in the etching liquid; and The position changing mechanism causes the plurality of core wire support members to reciprocate in the vertical direction at a speed of not less than 30 times and not more than 90 times per minute, wherein In the case where the hole is circular, the diameter of the hole is at least 1.1 times the diameter of the smallest circle containing the cross section of the silicon core wire, and When the hole has a shape other than a circle, the short diameter of the hole is 1.1 times or more the diameter of the smallest circle including the cross section of the silicon core wire.

2. The silicon core wire etching device according to claim 1, characterized in that: The edge portion forming the hole is formed in a continuous curved line shape.

3. The silicon core wire etching device according to claim 1, characterized in that: The silicon core wires respectively penetrate the holes formed in at least two of the core wire supporting members included in the plurality of core wire supporting members in the left-right direction. The distance between the two core wire supporting members can be changed according to the length of the silicon core wire.

4. The silicon core wire etching device according to claim 1, characterized in that: A plurality of the holes are formed in the core wire supporting member.

5. The silicon core wire etching device according to claim 1, characterized in that: Also available: a washing tank containing washing water in which the silicon core wire is immersed; and The position changing mechanism changes the relative position of the silicon core wire in the left-right direction with respect to the hole when the silicon core wire immersed in the etching solution penetrates the plurality of core wire supporting members in the left-right direction and is immersed in the washing water.

6. A method for etching a silicon core wire, characterized in that: have: A penetration step of allowing the silicon core wire to penetrate in a left-right direction through holes formed in a plurality of core wire support members that support the silicon core wire in the left-right direction; A first immersion step of immersing the silicon core wire supported by the core wire supporting member in an etching solution; a first position changing step of reciprocating the plurality of core wire supporting members in the up-down direction so as to change the relative position of the silicon core wires penetrating in the left-right direction with respect to the hole; and In the first position changing step, the plurality of core wire support members reciprocate in the vertical direction at a speed of not less than 30 times and not more than 90 times per minute, wherein In the case where the hole is circular, the diameter of the hole is at least 1.1 times the diameter of the smallest circle containing the cross section of the silicon core wire, and When the hole has a shape other than a circle, the short diameter of the hole is 1.1 times or more the diameter of the smallest circle including the cross section of the silicon core wire.

7. The method for etching a silicon core wire according to claim 6, characterized in that: Also available: a second immersion step of immersing the silicon core wires supported by the plurality of core wire supporting members in the left-right direction in washing water, the second immersion step being performed after the first position changing step; as well as The second position changing step is to move the plurality of core wire supporting members in the up-down direction or the front-rear direction so as to change the relative position of the silicon core wires immersed in the washing water through which the silicon core wires are inserted in the left-right direction with respect to the holes.

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