Manufacturing method of ingot block

Abstract

To provide a manufacturing method of ingot blocks that makes it easy to remove defects at corners.SOLUTION: A manufacturing method of an ingot block includes a chamfering step of circumferentially chamfering corners of the outer peripheral edge of an end face of a cylindrical ingot block.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing an ingot block. [Background technology]

[0002] 2. Description of the Related Art A method for manufacturing an ingot block in which the corners of a prismatic ingot block are chamfered is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3973843 [Patent Document 2] International Publication No. 2019 / 102629 Summary of the Invention [Problem to be solved by the invention]

[0004] The corners of the ingot block created through the cutting step are prone to defects such as chips and cracks. For this reason, it is necessary to chamfer the corners of the ingot block. However, since the corners of the prismatic ingot block have been conventionally chamfered, there are still angular parts when viewed in the height direction of the ingot block even after chamfering, and defects are likely to remain in these parts.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a method for manufacturing an ingot block which makes it easy to remove defects at the corners. [Means for solving the problem]

[0006] One aspect of the present invention is as follows.

[0007] [1] A method for manufacturing an ingot block, comprising a chamfering step of circumferentially chamfering corners of the outer peripheral edge of an end face of a cylindrical ingot block.

[0008] [2] The method for manufacturing an ingot block described in [1], further comprising an inspection step of inspecting the corners chamfered by the chamfering step.

[0009] [3] A method for manufacturing an ingot block as described in [2], which includes a removal step of performing corner removal to remove the corners of the ingot block to a predetermined depth or end face removal to remove the entire end face to a predetermined depth if determined necessary based on the results of the inspection step.

[0010] [4] The method for manufacturing an ingot block described in [3], wherein the corner removal is performed by again performing the chamfering step.

[0011] [5] The method for manufacturing an ingot block described in [4], wherein the corner removal is carried out under specified conditions such that the total chamfering length up to the completion of the corner removal is 3 mm or less for each side that forms the corner before chamfering.

[0012] [6] The method for producing an ingot block according to any one of [3] to [5], wherein the end face removal is carried out by cutting the ingot block.

[0013] [7] A method for manufacturing an ingot block described in any one of [1] to [6], wherein the first chamfering step is performed under conditions in which the length of the chamfer is 0.5 mm or more and 1.0 mm or less for each side forming the corner before chamfering.

[0014] [8] The method for producing an ingot block according to any one of [1] to [7], wherein the chamfering in the chamfering step is a C-chamfer. Effect of the Invention

[0015] According to the present invention, a method for manufacturing an ingot block can be provided that makes it easy to remove defects at corners. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a flow diagram showing a method for manufacturing an ingot block according to one embodiment of the present invention. [Diagram 2] 2 is a schematic diagram showing a chamfering step in the method for producing the ingot block shown in FIG. 1. FIG. [Diagram 3] FIG. 2 is a schematic diagram showing a chamfered corner of the ingot block shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] As shown in Figs. 1 to 3, in one embodiment of the present invention, a manufacturing method for an ingot block 1 includes a chamfering step S2 in which a corner 1b on an outer periphery of an end face 1a of a cylindrical ingot block 1 is chamfered on either side in a circumferential direction (a direction indicated by an arrow in Fig. 2). The circumferential direction is a direction going around a central axis O of the cylindrical ingot block 1. The circumferential chamfering in the chamfering step S2 utilizes relative rotation in the circumferential direction between the corner 1b and a grinding tool (not shown). For example, as shown in Fig. 1, the corner 1b may be chamfered by bringing the grinding tool into contact with the corner 1b while rotating the ingot block 1 in the circumferential direction, or the ingot block 1 may be fixed and the grinding tool moved in the circumferential direction to perform the chamfering.

[0019] According to the above configuration, the corner 1b is smoothly continuous in the circumferential direction by the ingot block 1 being cylindrical, and there is no angular portion when viewed in the axial direction of the ingot block 1 after chamfering. In addition, the ingot block 1 is cylindrical, so that the corner 1b can be easily chamfered by utilizing the relative rotation in the circumferential direction between the corner 1b and the grinding tool. Therefore, a manufacturing method of the ingot block 1 that is easy to remove defects in the corner 1b can be realized. The axial direction is the direction along the central axis O, which is the height direction of the cylinder. The grinding tool is not particularly limited, and is, for example, a grinding tool. The grinding tool has a grinding wheel, such as a diamond disk type, that has a processing surface that is pressed against the corner 1b and is rotated around a rotation axis perpendicular to the processing surface. The driving method of the grinding wheel is not particularly limited, and is, for example, an electric type.

[0020] The chamfering of the corner 1b may be performed using a holding device 2 that holds the ingot block 1 rotatably in the circumferential direction as shown in FIG. 2. The holding device 2 may have a configuration including a plurality of rotors 2a arranged in the circumferential direction as shown in FIG. 2. The rotors 2a may be rollers that can rotate about an axis P parallel to the central axis O of the ingot block 1 as shown in FIG. 2. The holding device 2 may have a configuration including a drive device (not shown) that drives at least one rotor 2a to rotate. The holding device 2 may not have a drive device, and chamfering may be performed by a person or a robot while rotating the ingot block 1 while the ingot block 1 is held by the holding device 2. According to the above configuration, chamfering can be achieved even more easily by using the holding device 2.

[0021] The manufacturing method of the ingot block 1 includes an inspection step S3 for inspecting the corner 1b chamfered in the chamfering step S2. If the defect appears on the corner 1b on the order of millimeters, it can be found by visual inspection or by visual inspection using equipment without using an X-ray device or the like. However, if the defect extends to the inside of the block on the order of microns, it is difficult to find the defect by visual inspection as it is. According to the above configuration, by chamfering, mechanical damage is given to the corner 1b by grinding, and defects such as cracks that are hidden in the corner 1b and difficult to find can be made visible, so that defects can be easily and inexpensively found by visual inspection. In addition, defects can be prevented from becoming visible in the subsequent process, so that production losses due to unnecessary processing can be suppressed.

[0022] The manufacturing method of the ingot block 1 includes a removal step S4 of performing corner removal to remove the corner 1b of the ingot block 1 to a predetermined depth or end face removal to remove the entire end face 1a to a predetermined depth, if it is determined to be necessary based on the result of the inspection step S3. The criteria for determining that removal is necessary are not particularly limited, and known criteria can be applied. The predetermined depth is a depth perpendicular to the surface of the chamfered corner 1b in the case of corner removal, and a depth (axial direction) perpendicular to the end face 1a in the case of end face removal. According to the above configuration, defects in the corner 1b found in the inspection step S3 can be removed by the removal step S4.

[0023] The corner removal is performed by the second chamfering step S2. According to the above-mentioned configuration, the corner removal can be easily performed. After the second chamfering step S2 is performed, the second inspection step S3 may be performed.

[0024] The corner removal is performed under a predetermined condition in which the total chamfering length at the time of completion of the corner removal is 3 mm or less for each side forming the corner 1b before chamfering. That is, under the above-mentioned predetermined condition, the length L1 of the side formed by the outer peripheral surface 1c of the total chamfering amount and the length L2 of the side formed by the end surface 1a of the total chamfering amount are each 3 mm or less. According to the above-mentioned configuration, the corner removal can be performed under the above-mentioned predetermined condition in which the total chamfering amount is not excessive.

[0025] The end face removal is performed by cutting the ingot block 1. According to the above configuration, the end face removal can be easily performed. As shown in FIG. 1, the manufacturing method of the ingot block 1 may have a cutting step S1 in which a cylindrical ingot block 1 to be subjected to a chamfering step S2 is formed by cutting, and the end face removal in the removing step S4 may be performed by a second cutting step S1. Note that the second cutting step S1 cuts the cylindrical ingot block 1 to be subjected to a second chamfering step S2 thereafter.

[0026] In the manufacturing method of the ingot block 1, if no defects are found in the inspection step S3, the ingot block 1 inspected in the inspection step S3 is used as a product, and if a defect is found in the inspection step S3, the removal step S4 and the subsequent inspection step S3 are repeated as necessary until no defects are found in the corner portion 1b in the inspection step S3. According to the above configuration, the ingot block 1 without defects in the corner portion 1b can be sent to the subsequent process.

[0027] In the removal step S4, when a defect is found in the inspection step S3, corner removal is performed under the above-mentioned predetermined conditions, and when the defect found in the inspection step S3 cannot be completely removed, end face removal is performed. With the above configuration, efficient defect removal can be realized. Note that the amount of corner removal in each removal step S4 may be preset, or the amount of corner removal may be adjusted by a person or a computer (such as artificial intelligence) based on the size of the defect (such as a crack) found in the inspection step S3.

[0028] The removal step S4 has a judgment step S4a for judging whether or not a removal process that can completely remove the defect by performing corner removal under the above-mentioned predetermined conditions is possible when a defect is found in the inspection step S3. If it is judged that the removal process is possible in the judgment step S4a, the corner removal is performed, and if it is judged that the removal process is impossible in the judgment step S4a, the end face removal is performed. According to the above configuration, it is possible to realize more efficient removal of defects. The method of judgment in the judgment step S4a is not particularly limited, and for example, a person or a computer (such as an artificial intelligence) may make the judgment based on the size of the defect found in the inspection step S3. The algorithm for the judgment is not particularly limited. There may be a case where the corner removal is performed based on the judgment in the judgment step S4a and then the corner removal is performed based on the result of the inspection step S3. That is, the accuracy of the judgment in the judgment step S4a is not particularly limited.

[0029] The first chamfering step S2 is performed under the condition that the length of the chamfer is 0.5 mm or more and 1.0 mm or less for each side forming the corner 1b before chamfering. That is, under the condition, the length L1 of the side formed by the outer peripheral surface 1c of the chamfer and the length L2 of the side formed by the end surface 1a of the chamfer are each 0.5 mm or more and 1.0 mm or less. According to the above configuration, the first chamfering step S2 can be performed under the condition that the chamfering amount is not excessive.

[0030] The chamfering in the chamfering step S2 is a C-chamfering. According to the above-mentioned configuration, the corner 1b can be easily chamfered.

[0031] The ingot block 1 is a silicon single crystal block (for example, a diameter of 100 mm to 450 mm, a length of 50 mm to 500 mm, and a weight of 100 kg or less). Since the silicon single crystal block is hard and brittle, defects are likely to occur at the corners 1b formed in the cutting step S1. According to the above configuration, a method for manufacturing a silicon single crystal block that is easy to remove defects at the corners 1b can be realized.

[0032] The cylindrical ingot block 1 has a corner 1b formed at one end in the axial direction and a corner 1b formed at the other end in the axial direction. The above-mentioned series of steps for removing defects at the corners 1b is preferably applied to both corners 1b, but may be applied to only one of them.

[0033] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and the above-described embodiment can be modified in various ways without departing from the gist of the present invention. [Explanation of symbols]

[0034] 1 ingot block 1a End face 1b Corner 1c Outer surface 2 Holding device 2a Rotating body S1 Cutting step S2 Chamfering step S3 Inspection Step S4 Removal step S4a Decision Step L1 Length of the edge formed by the outer periphery L2 Length of the edge formed by the end face O center axis P axis center

Claims

1. A method for manufacturing an ingot block, comprising a chamfering step of circumferentially chamfering corners of the outer peripheral edge of an end face of a cylindrical ingot block.

2. The method for manufacturing an ingot block according to claim 1 , further comprising an inspection step of inspecting the corners chamfered by the chamfering step.

3. 3. The method for manufacturing an ingot block as described in claim 2, further comprising a removal step of performing corner removal to remove the corners of the ingot block to a predetermined depth or end face removal to remove the entire end face to a predetermined depth when determined necessary based on the results of the inspection step.

4. The method for manufacturing an ingot block according to claim 3 , wherein the corner removal is performed by again performing the chamfering step.

5. 5. The method for manufacturing an ingot block according to claim 4, wherein the corner removal is performed under predetermined conditions such that a total chamfering length up to the time when the corner removal is completed is 3 mm or less for each side forming the corner before chamfering.

6. The method for producing an ingot block according to claim 3 , wherein the end surface removal is performed by cutting the ingot block.

7. 2. The method for manufacturing an ingot block according to claim 1, wherein the initial chamfering step is performed under conditions in which the length of the chamfer is 0.5 mm or more and 1.0 mm or less for each side forming the corner before chamfering.

8. The method for manufacturing an ingot block according to claim 1 , wherein the chamfering step is a C-chamfering step.

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