Manufacturing method of electrode plate for plasma treatment device and electrode plate for plasma treatment device
The method addresses the challenge of forming high-precision pores in electrode plates by using a two-step drilling process with different diameter drill bits, reducing breakage and ensuring uniform gas flow for plasma processing.
Patent Information
- Application Number
- TW110100549
- Authority / Receiving Office
- TW · TW
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2020-03-24
- Filing Date
- 2021-01-07
- Publication Date
- 2026-07-11
- Estimated Expiration
- 2041-01-06
Smart Images
Figure IMG-2_DRAW_110100549-A0304-14-0001-1 
Figure IMG-2_DRAW_110100549-A0304-14-0001-2 
Figure IMG-2_DRAW_110100549-A0304-14-0002-3
Abstract
Description
Technical Field
[0001] This invention relates to a method for manufacturing an electrode plate for a plasma treatment apparatus and the electrode plate for the plasma treatment apparatus. This case asserts the special petition filed with Japan on March 24, 2020. Priority to No. 2020-053222, the contents of which are incorporated herein by reference. Prior Technology
[0002] Plasma processing apparatuses, such as plasma etching apparatuses or plasma CVD apparatuses used in semiconductor device manufacturing processes, have upper and lower electrodes, connected to a high-frequency power supply, arranged facing each other vertically within a chamber. The lower electrode has a substrate to be processed mounted on it, and the upper electrode has a vent hole through which etching gas flows to the substrate while a high-frequency voltage is applied. Thus, the plasma processing apparatus is configured to generate plasma and perform etching or other processes on the substrate.
[0003] Patent Document 1 discloses an electrode plate for plasma etching that can suppress the generation of microparticles. This electrode plate, formed of monocrystalline silicon, has through-holes (pores) arranged parallel to its thickness direction. The through-holes consist of large-diameter straight hole portions and small-diameter straight hole portions. According to this electrode plate, large microparticles are not generated, reducing the number of cleaning cycles and allowing for more efficient plasma etching of silicon wafers compared to conventional methods.
[0004] Thicker electrode plates generally have longer lifespans. Recently, deeper etching is required for complex, multi-layered three-dimensional structures of the substrate (e.g., 3D NAND), necessitating increased etching gas pressure. This leads to faster pore wear and shorter lifespans for conventionally thicker electrode plates. Therefore, thicker electrode plates with longer lifespans are desired. On the other hand, there are methods for machining pores on electrode plates, including drilling, laser machining, water jet machining, and electrical discharge machining. Laser machining can only achieve a hole depth of a few millimeters (approximately 5 mm). Water jet machining cannot effectively machine the shape of the pore opening. Electrical discharge machining can only use charged materials. In contrast, drilling offers advantages in terms of machinability, versatility, and quality. [Previous Technical Documents] [Patent Literature]
[0005] [Patent Document 1] Japanese Patent Application Publication No. 2001-102357 Summary of the Invention
[0006] [The problem that the invention aims to solve]
[0007] However, even in this drilling process, for example, when the diameter of the pore is 0.5mm to 1.0mm and the depth increases, the drill bit shakes due to the processing load, which can cause the pore roundness to become larger (worse), potentially reducing the quality of plasma treatment.
[0008] The present invention was made in view of the above-mentioned matters, and its object is to provide a method for manufacturing an electrode plate for a plasma processing apparatus that can form pores with smaller roundness even when the pore depth exceeds 12 mm, and an electrode plate for a plasma processing apparatus having pores with smaller roundness. [Methods for solving the problem]
[0009] One aspect of the present invention is a method for manufacturing an electrode plate for a plasma treatment device, which involves forming a plurality of air holes having straight sections with a length of at least 12 mm in parallel and through-hole configurations in the thickness direction of the electrode plate body. The manufacturing method includes: a guide hole forming process, in which a guide hole with a diameter of 50% or more and 80% or less of the diameter of the straight section is formed from one surface of the electrode plate body using a first drill bit; and a straight section forming process, in which the straight section is formed by overlapping the guide hole using a second drill bit.
[0010] According to the manufacturing method of the electrode plate for the plasma treatment device, after forming a guide hole with a diameter of 50% to 80% of the diameter of the straight section using a first drill bit, the straight section is formed using a second drill bit. Therefore, the second drill bit performs drilling with a lower machining load, reducing the cutting area of the guide hole compared to the original straight section. Because the machining load of the second drill bit is reduced, the machining accuracy of the second drill bit can be improved, and a straight section with less roundness can be formed. In this case, if the diameter of the guide hole is less than 50% of the diameter of the straight section, the effect of reducing the machining load of the second drill bit is less significant; if it exceeds 80%, the machining load of the smaller-diameter first drill bit becomes larger, and the first drill bit may break.
[0011] As the machining depth increases (the electrode plate becomes thicker), the machining load on the drill bit also increases, making it prone to bending. Therefore, single-crystal diamond drill bits or polycrystalline diamond drill bits, sintered drill bits, and drill bits with oil filler ports can be used. By employing manufacturing methods such as the following, the risk of drill bit breakage caused by machining load can be avoided.
[0012] In one embodiment of the manufacturing method of the present invention, during the aforementioned guide hole forming process, the guide hole can be formed using the aforementioned first drill bit up to the midpoint of the thickness of the aforementioned electrode plate body. In this case, the machining depth of the aforementioned guide hole can be greater than 5 mm.
[0013] According to the manufacturing method of the electrode plate for the plasma treatment device, before forming the pores on the electrode plate body, a guide hole is formed up to the midpoint of the thickness direction, with an inner diameter of 50% to 80% of the inner diameter of the straight portion of the pore. Since the guide hole only needs to be formed up to the midpoint of the thickness direction of the electrode plate body, the cutting length of the first drill bit can be shorter than the thickness of the electrode plate body. That is, even if the diameter of the first drill bit used for the guide hole is small, it becomes shorter, thus reducing the risk of breakage. In this case, compared to a straight section with a length exceeding 12mm, if the length of the guide hole is less than 5mm, the effect of reducing the machining load of the second drill bit is less, so it can be formed to have a length greater than 5mm.
[0014] On the other hand, the second drill bit, which has a larger diameter than the first drill bit, is used to drill a pilot hole drilled by the first drill bit, for example, in the same direction and coaxially with the pilot hole. Here, by drilling coaxially with the pilot hole, the second drill bit reduces the machining load on the portion corresponding to the removed pilot hole cutting area. Therefore, the second drill bit can perform drilling with a smaller machining load compared to the original straight section cutting area, which has been reduced to less of the pilot hole cutting area. Consequently, the second drill bit is less prone to bending as the machining load accumulates. As a result, even when the cutting length of the second drill bit is longer than that of the first drill bit, the risk of breakage is reduced corresponding to the reduced machining load. Ideally, the second drill bit should be drilled coaxially with the pilot hole formed by the first drill bit, but slight deviations within the diameter difference between the two drill bits are permissible.
[0015] In one aspect of the manufacturing method of the present invention, the aforementioned second drill bit can be drilled from one surface of the aforementioned electrode plate body or from another surface of the aforementioned electrode plate body.
[0016] In the manufacturing method of the electrode plate for the plasma treatment apparatus, when the second drill bit drills from another surface of the electrode plate body, the drilling is performed in the opposite direction to when the first drill bit forms the guide hole. Even in this case, by drilling approximately coaxially with the guide hole, the machining load after reaching the guide hole cutting area that has been removed from one surface can be reduced in the portion corresponding to the guide hole cutting area. Therefore, compared to drilling the original integral pore, the overall machining load is also reduced. When the second drill bit reaches a predetermined depth from the other surface, it connects to the guide hole formed from one surface. Afterward, the second drill bit can reduce the machining load in the portion corresponding to the guide hole cutting area.
[0017] Therefore, the second drill bit can perform drilling operations with a reduced machining load from the original cutting area of the overall straight section to the pilot hole cutting area, making it possible to start drilling from the middle of the thickness direction (after reaching the pilot hole cutting area). Thus, in the second drill bit, the machining load from the middle of the thickness direction can be reduced, and bending caused by the cumulative increase in machining load is less likely to occur. That is, even if the cutting length of the second drill bit is longer than that of the first drill bit, the risk of breakage corresponding to the reduced machining load is also reduced.
[0018] As a method to ensure coaxial machining between the first and second drill bits, a hole other than a vent hole can be used as a reference hole, and its position information can be set in the machining center. By setting the machining positions of the first and second drill bits to the same coordinates, coaxial machining can be performed. The same applies when the second drill bit drills from another surface of the electrode plate body. Furthermore, changing from the first drill bit to the second drill bit is usually done automatically and coaxially from the drill changer (drill bit, tool magazine) in the machining center using an automatic change function.
[0019] In one aspect of the manufacturing method of the present invention, if the aforementioned second drill bit performs drilling from another surface of the aforementioned electrode plate body, the aforementioned straight portion can be formed up to the midway point of reaching the aforementioned guide hole and up to the thickness of the aforementioned electrode plate body.
[0020] The pores formed by this manufacturing method result in a stepped hole shape, with a small-diameter hole serving as a guide hole on one surface of the electrode plate body and a large-diameter hole forming a straight section on the other surface. This also reduces the machining load on each drill bit, making it suitable for use with thick electrode plates.
[0021] An electrode plate for a plasma treatment apparatus according to one embodiment of the present invention is an electrode plate for a plasma treatment apparatus having a plurality of parallel and through pores provided in the thickness direction of the electrode plate body. In the electrode plate, the aforementioned pores have a straight portion with a length of at least 12 mm, and the straight portion has a diameter of 0.5 mm or more and 1.0 mm or less, and a roundness of 0.01 mm or less.
[0022] According to the electrode plate used in this plasma processing apparatus, the length of the straight section is at least 12 mm, so the electrode plate body is formed with a thickness of more than 12 mm, which can achieve a long service life. In addition, since the roundness of the straight section is less than 0.01 mm, it is not easy to generate non-uniformity in gas flow.
[0023] In the electrode plate of the plasma treatment apparatus, in the aforementioned pores, a small-diameter portion opening on one surface of the aforementioned electrode plate body and a large-diameter portion opening on the other surface are connected in the middle of the thickness direction, and the aforementioned large-diameter portion can be said to be the aforementioned straight portion. [Invention Effects]
[0024] According to the manufacturing method of the electrode plate for a plasma treatment apparatus according to the present invention, even when processing pores on an electrode plate for a plasma treatment apparatus with a thickness exceeding 12 mm, the risk of drill bit breakage can be reduced, and high-precision pores can be formed. Based on this electrode plate for a plasma treatment apparatus, the service life can be extended by using a thicker electrode plate. Furthermore, since the roundness of the straight portion is less than 0.01 mm, non-uniformity in gas flow is less likely to occur. Simple Explanation of the Diagram
[0025] [Figure 1] Plan view of an electrode plate for a plasma treatment apparatus according to an embodiment of the present invention. [Figure 2] Longitudinal cross-section of an important part of Figure 1. [Figure 3] shows a cross-sectional view of the state in which the guide hole is formed during the guide hole forming process in the manufacturing method of the embodiment. [Figure 4] A cross-sectional view of the straight section formed in the same direction as the guide hole during the straight section forming process after the guide hole forming process. [Figure 5] A cross-sectional view of the straight section formed in the direction opposite to the guide hole during the straight section forming process after the guide hole forming process. [Figure 6] shows a cross-sectional view of an example of a stepped vent formed by a guide hole and a straight section. [Figure 7] shows a cross-sectional view of the state after the guide hole formation process, in order to form a straight section up to the middle of the thickness direction of the electrode plate body, with the second drill bit configured. [Figure 8] shows a cross-sectional view of a hole with a diameter smaller than that of a straight section formed by the third drill bit up to the middle of the thickness direction of the electrode plate body. [Figure 9] shows a cross-sectional view of a stepped pore shape formed by the method shown in Figure 8. Implementation
[0026] The embodiments of the present invention will now be described with reference to the drawings. Figure 1 is a plan view of an electrode plate for a plasma processing apparatus according to an embodiment of the present invention. The electrode plate (hereinafter simply referred to as "electrode plate") 11 for the plasma processing apparatus has multiple (hundreds to 1000, at least 100, or at least 500) pores 21 spaced a few mm to 10 mm apart, for example, arranged in a longitudinal and transverse manner parallel to the thickness direction and penetrating through the electrode plate body 12, which is formed from monocrystalline silicon, columnar silicon, or polycrystalline silicon into a circular plate with a thickness t of more than 12 mm and less than 30 mm and a diameter of more than 200 mm and less than 550 mm. Each pore 21 has a straight portion 22 with a length of at least 12 mm in the thickness direction of the electrode plate body 12. In the example shown in FIG2, the pore 21 is formed as a straight hole along the entire thickness of the electrode plate body 12. Therefore, the straight portion 22 of this embodiment constitutes the entire length of the pore 21, which exceeds 12 mm. The diameter d of the straight section 22 is 0.5 mm or more and 1.0 mm or less, and the roundness is 0.01 mm or less.
[0027] The electrode plate 11 for the plasma processing device is manufactured by etching, polishing and other processes after forming pores on the disc-shaped electrode plate body 12 obtained by slicing silicon ingots such as monocrystalline silicon. The formation of the pores includes: a guide hole forming process, in which a guide hole 23 is formed by a first drill bit 31 from one surface of the electrode plate body 12 to the middle of the thickness of the electrode plate body 12, wherein the diameter of the guide hole 23 is more than 50% and less than 80% of the diameter of the hole used to form the straight portion 22; and a straight portion forming process, in which a pore 21 is formed by using a second drill bit 32 and forming the straight portion 22 by overlapping with the guide hole 23.
[0028] Drill bits 31 and 32 can be made of sintered tungsten (W) material, drill bits electroplated with diamond particles, polycrystalline diamond, or monocrystalline diamond. The results of selecting these drill bits show that monocrystalline diamonds are particularly suitable due to the lowest number of breakage points.
[0029] The porosity formation process is described in more detail below. First, in the guide hole formation process, the guide hole 23 is formed up to the midpoint of the thickness of the electrode plate body 12. The inner diameter of the guide hole 23 is 50% to 80% of the inner diameter of the straight portion 22 of the porosity 21. If the diameter of the straight portion 22 is 0.5 mm to 1.0 mm, for example, the diameter of the guide hole 23 is set to 0.3 mm to 0.8 mm. The guide hole 23 is formed using a first drill bit 31 up to the midpoint of the thickness of the electrode plate body 12, for example, to a depth L1 of approximately 8 mm. Therefore, the diameter d1 of the first drill bit 31 is smaller than the diameter of the straight portion 22. Figure 3 shows the state of the guide hole 23 being formed using the first drill bit 31. After forming to a depth L1 = 8 mm, the first drill bit 31 is withdrawn from the guide hole 23.
[0030] Next, in the process of forming the straight section, a straight section 22 with a diameter 0.5 mm to 1.0 mm larger than the guide hole 23 is formed by the second drill bit 32 and penetrates the electrode plate body 12. For example, the straight section 22 is formed with a diameter approximately 0.2 mm larger than the guide hole 23 (0.1 mm larger on each side). Therefore, the diameter d2 of the second drill bit 32 is larger than the diameter d1 of the first drill bit 31. In Figures 3 and 4, the guide hole cutting area 41 formed during the guide hole forming process is shown as a solid line, and the straight section cutting area 42 to be formed during the straight section forming process is shown as a dashed line. In the example shown in Figures 3 and 4, the second drill bit 32 drills from the same direction as the first drill bit 31 when machining the guide hole 23 and coaxially with the guide hole 23. In the straight section forming process, the second drill bit 32 drills until it penetrates the electrode plate body 12. Therefore, the straight section 22 is formed over the entire thickness of the electrode plate body 12.
[0031] In the above manufacturing method, a guide hole 23 is formed before the pore 21 is formed in the electrode plate body 12, extending to the midpoint of the thickness direction. The guide hole 23 has an inner diameter that is 50% to 80% of the inner diameter of the straight portion 22 of the pore 21. Since the guide hole 23 only needs to be formed to the midpoint of the thickness direction of the electrode plate body 12, the cutting length of the first drill bit 31 can be shorter than the thickness of the electrode plate body 12. That is, although the diameter of the first drill bit 31 used for the guide hole is small, its short length makes it less prone to breakage.
[0032] The second drill bit 32 has a larger diameter and a longer length than the first drill bit 31, with a linear length exceeding at least 12 mm. However, the second drill bit 32 performs drilling from the guide hole 23 already drilled by the first drill bit 31, coaxially with the guide hole 23, until it penetrates the electrode plate body 12. That is, by drilling coaxially with the guide hole 23, the machining load corresponding to the portion of the removed guide hole cutting area 41 can be reduced. Therefore, the second drill bit 32 can perform drilling with less machining load, reducing the cutting area of the guide hole cutting area 41 from the original cutting area of the entire air hole 21 (straight portion 22). Therefore, the second drill bit 32 is less prone to bending due to the cumulative increase in machining load. As a result, although the cutting length of the second drill bit 32 is longer than that of the first drill bit 31, the risk of breakage is reduced for the portion with reduced machining load. As mentioned above, the diameters of the first drill bit 31 and the second drill bit 32 are different. Therefore, the pores 21 of the electrode plate body 12 are formed by at least two drill bits (e.g., the first drill bit 31 and the second drill bit 32) with different diameters. It is preferable that the second drill bit 32 is drilled coaxially with the guide hole 23 already formed by the first drill bit 31, but slight deviations within the diameter difference between the two drill bits 31 and 32 are permissible.
[0033] When the length of the straight portion 22 exceeds 12mm but is less than 30mm, the machining depth of the guide hole 23 in the first drill bit 31 is preferably greater than 5mm but less than 15mm. If the machining depth of the guide hole 23 is too shallow (less than 5mm), it will not be able to reduce the machining load in the second drill bit 32, and there will be problems such as breakage or reduced roundness of the second drill bit 32. When the machining depth of the guide hole 23 is too deep, the machining load of the first drill bit 31 increases, and the first drill bit 31 may break. It is more preferably 7mm or more but less than 13mm. Therefore, if the thickness of the electrode plate body 12 is less than 15mm, preferably less than 13mm, the guide hole 23 in the first drill bit 31 can be formed by penetrating the electrode plate body 12.
[0034] In the electrode plate 11 obtained by this manufacturing method, the pore 21 has a straight portion 22 with a length of at least 12 mm. In the example shown in FIG2, the entire length of the pore 21 is the straight portion 22. The diameter of the straight portion 22 is 0.5 mm or more and 1.0 mm or less, and the roundness is 0.01 mm or less.
[0035] Based on the electrode plate 11, the length of the straight portion 22 is at least 12 mm, so the electrode plate body 12 is formed with a thickness of more than 12 mm, which can achieve a long service life. In addition, since the roundness of the straight portion 22 is less than 0.01 mm, it is not easy to generate non-uniformity in gas flow.
[0036] When using two drill bits for drilling, the following method can also be considered. (1) The outer diameter of the two drill bits is set to be the same as the outer diameter that can form the final air hole. The first drill bit is used to drill up to the middle of the thickness of the electrode plate body, and the second drill bit is used to drill through the electrode plate body a second time from the hole. (2) The outer diameter of the two drill bits is the same as the outer diameter that can form the final air hole. The first drilling is performed using the first drill bit up to the middle of the thickness of the electrode plate body. With the front end of the second drill bit inserted into the hole, the second drilling is performed from the end of the hole that has been drilled for the first time to penetrate the electrode plate body. In their methods (1) and (2), a short-cutting-length drill bit can be used during the first drilling operation, thus reducing the risk of drill bit breakage. However, a positional shift occurs between the first and second drilled holes, causing deformation at the hole's opening and potentially reducing the hole's roundness. During the second drilling operation, the drill bit wobbles, thus posing a risk of breakage.
[0037] In this invention, as described above, the second drill bit 32 can perform drilling from the same direction as the first drill bit 31 in which the guide hole 23 is formed, or it can perform drilling from the opposite side of the electrode plate body 12, unlike the first drill bit 31. Figure 5 shows an example where the second drill bit 32 is machining the straight section 22 from a direction opposite to the direction in which the guide hole 23 is formed. Similar to Figure 3, the first drill bit 31 drills from one surface of the electrode plate body 12 to the midpoint of its thickness to form the guide hole 23. In contrast, the second drill bit 32 drills from the other surface of the electrode plate body 12 (the surface opposite to one surface, or the surface facing one surface) and coaxially with the guide hole 23 until it penetrates the electrode plate body 12. This allows the straight section 22 to penetrate the entire thickness of the electrode plate body 12. Therefore, the shape of the formed pore 21 is the same as in the machining cases shown in Figures 3 and 4, becoming the shape of a straight hole as shown in Figure 2.
[0038] In this invention, the straight portion 22 does not necessarily have to be formed to extend through the electrode plate body 12. Similar to Figure 5, Figure 6 shows a straight section 22 formed from the opposite side of the electrode plate body 12 relative to the guide hole 23. However, the straight section 22 only reaches the depth L2 of the front end of the guide hole 23, that is, only reaches the middle of the thickness of the electrode plate body 12, thereby forming a stepped vent 211 that connects the guide hole 23 and the straight section 22. In this case, the guide hole 23 becomes a small-diameter portion 24 formed from one surface side of the electrode plate body 12 to the midpoint of the thickness direction. The straight portion 22 becomes a large-diameter portion 25 formed from the other surface side of the electrode plate body 12, coaxial with and communicating with the small-diameter portion 24, to the midpoint of the thickness direction of the electrode plate body 12. Thus, a stepped-shaped vent 211 formed by connecting the small-diameter portion 24 and the large-diameter portion 25 is formed on the electrode plate body 12.
[0039] The pores 21 and 211 formed by the method shown in Figures 3 to 6 above have a straight portion 22 with a length of at least 12 mm, the diameter of the straight portion 22 being 0.5 mm or more and 1.0 mm or less, and the roundness being 0.01 mm or less.
[0040] In the case of forming stepped pores, the method shown in Figures 7 to 9 can also be used. In this example, firstly, relative to the guide hole cutting area 41 formed by the first drill bit 31 (omitted in Figures 7 and 8, refer to Figure 3) from one surface of the electrode plate body 12 to the midpoint of its thickness, as shown in Figure 7, a straight section 22 (refer to Figure 8) is formed coaxially in the same direction and within a length L2 up to the midpoint of the thickness of the electrode plate body 12 by the second drill bit 32. Next, a third drill bit 33 is used to perform drilling coaxially from the other surface of the electrode plate body 12 up to the depth of the straight section cutting area 42, resulting in the state shown in Figure 9. In the example shown in Figures 7 to 9, the diameter of the third drill bit 33 is smaller than the diameter of the second drill bit 32, the straight section 22 is a large-diameter section 25, and the hole formed by the third drill bit 33 is a small-diameter section 24, forming a stepped vent 212 that connects them at the midpoint of the thickness of the electrode plate body 12. In this case, the straight section 22 is also formed to a length L2 exceeding 12 mm. Although the diagram is omitted, the diameter of the third drill bit 33 is set to be smaller than the diameter of the second drill bit 32. However, a third drill bit with a larger diameter than the second drill bit 32 can also be used to process and form a hole that communicates with the straight section 22. In this way, the straight section 22 becomes a small diameter section, and the hole formed by the third drill bit 33 becomes a large diameter section. [Example]
[0041] Samples were created using various drilling methods. After drilling, a 3D image measuring machine (Mitutoyo Co., Ltd.'s Quick) was used. The VisionQVX606-PRO was used to measure the diameter and roundness of the opening on the inlet side of the second drill bit using image processing, and also to confirm whether the drill bit broke during machining. Five tests (five drilling operations) were conducted, and the average values for the diameter and roundness were calculated. The number of drill bits that broke in each of the five tests was investigated. Drill bits that broke were excluded from the test sample.
[0042] [Example 1] A straight hole with a target diameter of 0.8 mm is formed through the electrode plate body with a thickness of 20 mm. (1) Traditional processing method A A hole was drilled in one pass from one surface of the electrode plate body using a drill bit with a diameter of 0.8 mm and a cutting length of 20 mm. (2) Processing method A of the comparative example After machining a 10mm deep guide hole from one surface of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 10mm (Drill bit 1: In the comparative example, the initial drill bit is also referred to as drill bit 1, and the second drill bit is referred to as drill bit 2. The same applies below.), a 20mm deep hole was drilled from one surface of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 20mm (Drill bit 2) to penetrate the electrode plate body by including the guide hole. (3) Processing method B of the comparative example After drilling a 10mm deep guide hole from one surface of the electrode body using a drill bit with a diameter of 0.8mm and a cutting length of 10mm (the first drill bit), the tip of a drill bit with a diameter of 0.8mm and a cutting length of 20mm (the second drill bit) was inserted into the guide hole, and a 10mm deep hole was drilled from the 10mm position to penetrate the electrode plate body. (4) Processing method A of the embodiment After drilling a 10mm deep guide hole from one surface of the electrode plate body using a first drill bit with a diameter of 0.6mm and a cutting length of 10mm, a 20mm deep hole was drilled from one surface of the electrode plate body using a second drill bit with a diameter of 0.8mm and a cutting length of 20mm, penetrating the electrode plate body by including the guide hole. Their results are shown in Table 1. The evaluation of drill bit breakage in the conventional example is recorded in the column for drill bit 1 (the same applies to Tables 2 and 3).
[0043]
[0044] In the traditional example A, all five tests resulted in drill bit breakage, so the hole diameter or roundness was not measured. Comparative examples A and B both resulted in drill bit (second drill bit) breakage in 3 out of 5 tests, and the error of the hole diameter relative to the target hole diameter also increased, and the roundness was also poor. In contrast, in the processing method of Example A, it was confirmed that no drill bit was damaged, the error in the diameter of the processed hole was small, and holes with small roundness could be processed.
[0045] [Example 2] A straight hole with a target diameter of 0.8 mm is formed through the electrode plate body with a thickness of 30 mm. (1) Processing method B of the traditional example A hole was drilled in one pass from one surface of the electrode plate body using a drill bit with a diameter of 0.8 mm and a cutting length of 30 mm. (2) Processing method C of the comparative example After drilling a 10mm deep guide hole from one surface of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 10mm (the first drill bit), a 30mm deep hole was drilled from one surface of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 30mm (the second drill bit) in a manner that includes the guide hole, thus penetrating the electrode plate body. (3) Processing method D of the comparative example After drilling a 10mm deep guide hole from one surface of the electrode body using a drill bit with a diameter of 0.8mm and a cutting length of 10mm (the first drill bit), the tip of a drill bit with a diameter of 0.8mm and a cutting length of 30mm (the second drill bit) was inserted into the guide hole, and a 20mm deep hole was drilled from the 10mm position to penetrate the electrode plate body. (4) Processing method B of the embodiment After drilling a 10mm deep guide hole from one surface of the electrode plate body using a first drill bit with a diameter of 0.6mm and a cutting length of 10mm, a 30mm deep hole was drilled from one surface of the electrode plate body using a second drill bit with a diameter of 0.8mm and a cutting length of 30mm, thus penetrating the electrode plate body. Their results are shown in Table 2.
[0046]
[0047] In conventional example B, all five tests resulted in drill bit breakage. In comparative examples C and D, the second drill bit broke in all five tests, so the hole diameter or roundness was not measured. In the processing method of Example B, it was confirmed that no drill bit broke, the error in the diameter of the processed hole was small, and holes with small roundness could be processed. As described above, the method according to the present invention is effective even when processing air holes with a straight section of 30 mm in length.
[0048] [Example 3] A straight hole with a target diameter of 0.8 mm is formed through the electrode plate body with a thickness of 13 mm. (1) Traditional processing method C A hole was drilled in one pass from one surface of the electrode plate body using a drill bit with a diameter of 0.8 mm and a cutting length of 13 mm. (2) Processing method E of the comparative example After drilling a 10mm deep guide hole from one surface of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 10mm (the first drill bit), a 13mm deep hole was drilled from one surface of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 13mm (the second drill bit) to penetrate the electrode plate body by including the guide hole. (3) Processing method F of the comparative example After drilling a 10mm deep guide hole from one surface of the electrode body using a drill bit with a diameter of 0.8mm and a cutting length of 10mm (the first drill bit), the tip of a drill bit with a diameter of 0.8mm and a cutting length of 13mm (the second drill bit) was inserted into the guide hole, and a 3mm deep hole was drilled from the 10mm position to penetrate the electrode plate body. (4) Processing method C of the embodiment After drilling a 10mm deep guide hole from one surface of the electrode plate body using a first drill bit with a diameter of 0.6mm and a cutting length of 10mm, a 13mm deep hole was drilled from one surface of the electrode plate body using a second drill bit with a diameter of 0.8mm and a cutting length of 13mm, thus penetrating the electrode plate body. (5) Processing method D of the embodiment After drilling a 13mm deep guide hole (through hole) from one surface of the electrode plate body using a first drill bit with a diameter of 0.6mm and a cutting length of 13mm, the electrode plate body was manufactured by drilling a 13mm deep hole from one surface of the electrode plate body using a second drill bit with a diameter of 0.8mm and a cutting length of 13mm, in a manner including the guide hole. Their results are shown in Table 3.
[0049]
[0050] In the conventional example, drill bit breakage occurred in 3 out of 5 tests. In comparative examples E and F, drill bit breakage occurred in the second drill bit in 1 out of 5 tests. However, because the hole depth was less than in examples 1 and 2, drill bit breakage was less frequent. Although drilling could be completed, the diameter error of the resulting hole increased, and the roundness did not meet the requirements. In comparative example F, the drilling of the second drill bit involved a 3mm depth, resulting in a smaller load. However, it was prone to wobbling in the first hole drilled, leading to breakage in 1 out of 5 tests. In Example C, no drill bit broke, the hole diameter error was small, and the roundness was also small. In Example D, although it was confirmed that the first drill bit broke once out of five tests, the error in the hole diameter and the roundness were small.
[0051] As can be seen from the above embodiments, the manufacturing method according to the present invention can form holes with a length of more than 12 mm with high precision (small roundness) even for electrode plate bodies that are thick. [Industry availability]
[0052] According to the manufacturing method of the electrode plate for plasma processing apparatus of the present invention, even when performing pore processing on electrode plates for plasma processing apparatus with a thickness exceeding 12 mm, the risk of drill bit breakage can be reduced, and high-precision pores can be formed. The electrode plate for plasma processing apparatus, being a thick electrode plate, achieves a long service life. Furthermore, since the roundness of the straight portion is less than 0.01 mm, gas flow non-uniformity is less likely to occur.
[0053] 11: Electrode plate (electrode plate for plasma treatment device) 12: Electrode plate body 21,211,212: Stomata 22: Straight section 23: Guide hole 24: Small diameter part 25: Large diameter section 31: Drill Bit 1 32: Drill bit number 2 41: Guide hole cutting area 42: Cutting area of straight section
Claims
1. A method for manufacturing an electrode plate for a plasma treatment apparatus, comprising forming a plurality of holes having straight portions with a length of at least 12 mm in parallel and through-hole configuration in the thickness direction of the electrode plate body, the method being characterized by: a guide hole forming process, wherein a guide hole with a diameter of 50% to 80% of the diameter of the hole forming the straight portion is formed from one surface of the electrode plate body using a first drill bit; and a straight portion forming process, wherein a second drill bit is coaxial with the guide hole and... The aforementioned straight section is formed by overlapping the aforementioned guide holes; in the aforementioned guide hole forming process, the machining depth of the aforementioned guide holes exceeds 5 mm; in the aforementioned straight section forming process, the aforementioned second drill bit is used to reach the aforementioned guide hole from the other surface of the aforementioned electrode plate body, and the aforementioned straight section is formed up to the middle of the thickness of the aforementioned electrode plate body; the aforementioned electrode plate body is formed only by monocrystalline silicon, columnar silicon or polycrystalline silicon, the diameter of the aforementioned second drill bit is larger than the diameter of the aforementioned first drill bit, and the aforementioned straight section forming process is performed after the aforementioned guide hole forming process.
2. A method for manufacturing an electrode plate for a plasma treatment apparatus, comprising forming a plurality of pores having straight portions with a length of at least 12 mm in the thickness direction of the electrode plate body in a parallel and through manner, the method comprising: a guide hole forming process, wherein a guide hole with a diameter of 50% to 80% of the diameter of the hole forming the straight portion is formed from one surface of the electrode plate body using a first drill bit; a straight portion forming process, wherein the straight portion is formed coaxially with and overlapping the guide hole using a second drill bit; and a hole forming process, wherein a hole coaxially with the guide hole and reaching the straight portion is formed from another surface of the electrode plate body using a third drill bit; wherein, In the aforementioned guide hole forming process, the machining depth of the aforementioned guide hole exceeds 5 mm; in the aforementioned straight section forming process, the aforementioned straight section is formed from the aforementioned surface of the aforementioned electrode plate body to the middle of the thickness of the aforementioned electrode plate body using the aforementioned second drill bit; the aforementioned electrode plate body is formed only of monocrystalline silicon, columnar silicon, or polycrystalline silicon; the diameter of the aforementioned second drill bit is larger than the diameter of the aforementioned first drill bit; the diameter of the aforementioned third drill bit is smaller than the diameter of the aforementioned second drill bit; and the aforementioned straight section forming process is performed after the aforementioned guide hole forming process.
3. A method for manufacturing an electrode plate for a plasma processing apparatus as claimed in claim 1 or 2, wherein the aforementioned guide hole is formed up to the middle of the thickness of the aforementioned electrode plate body.
4. An electrode plate for a plasma treatment apparatus, comprising a plurality of parallel and through pores disposed in the thickness direction of the electrode plate body, characterized in that: the electrode plate body is formed only of monocrystalline silicon, columnar silicon, or polycrystalline silicon; in the electrode plate, the pores have a straight portion with a length of at least 12 mm and opening on one surface of the electrode plate body as a gas outlet surface; the diameter of the opening on one surface of the electrode plate body of the straight portion is 0.5 mm or more and 1.0 mm or less; and the roundness of the opening on one surface of the electrode plate body is 0.01 mm or less; the small-diameter portion of the pore opening on another surface of the electrode plate body and the large-diameter portion opening on one surface of the electrode plate body are connected in the middle of the thickness direction, and the large-diameter portion is the straight portion.