WO2010038595A1 - Method of producing glass substrate for magnetic disk - Google Patents

Method of producing glass substrate for magnetic disk Download PDF

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Publication number
WO2010038595A1
WO2010038595A1 PCT/JP2009/065817 JP2009065817W WO2010038595A1 WO 2010038595 A1 WO2010038595 A1 WO 2010038595A1 JP 2009065817 W JP2009065817 W JP 2009065817W WO 2010038595 A1 WO2010038595 A1 WO 2010038595A1
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WO
WIPO (PCT)
Prior art keywords
glass substrate
drilling tool
hole
center
shaft
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PCT/JP2009/065817
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French (fr)
Japanese (ja)
Inventor
明男 藤村
正 木下
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コニカミノルタオプト株式会社
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Publication of WO2010038595A1 publication Critical patent/WO2010038595A1/en

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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/84—Processes or apparatus specially adapted for manufacturing record carriers
    • G11B5/8404—Processes or apparatus specially adapted for manufacturing record carriers manufacturing base layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28D—WORKING STONE OR STONE-LIKE MATERIALS
    • B28D1/00—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor
    • B28D1/02—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by sawing
    • B28D1/04—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by sawing with circular or cylindrical saw-blades or saw-discs
    • B28D1/041—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by sawing with circular or cylindrical saw-blades or saw-discs with cylinder saws, e.g. trepanning; saw cylinders, e.g. having their cutting rim equipped with abrasive particles

Definitions

  • the present invention relates to a method of manufacturing a glass substrate for a magnetic disk used for a substrate of a magnetic disk recording apparatus.
  • a magnetic disk recording device used for a computer or the like for example, a hard disk, an aluminum alloy or glass disk is used as a substrate. A metal magnetic thin film is formed on this substrate, and information is recorded by magnetizing the metal magnetic thin film with a magnetic head.
  • FIG. 6 is a flowchart showing in sequence the manufacturing process of the glass substrate for magnetic recording media according to the prior art.
  • a glass material is melted (step S20: glass melting step), the molten glass is poured into a planar mold, the molten glass is sandwiched between the molds, and press-molded to produce a disk-shaped glass substrate.
  • Step S21: Press molding process A glass substrate that is a semi-finished product that is produced by this press molding process and is subjected to the grinding / polishing process described below is referred to as a “blank material”.
  • a circular through hole is formed at the center of the surface of the blank material using a diamond core drill to produce a donut-shaped glass substrate (perforated blank material) (step S22: coring step).
  • step S23 first lapping step.
  • first lapping step both surfaces of the perforated blanks are ground and the parallelism, flatness and thickness of the glass substrate are preliminarily adjusted.
  • step S24 End grinding process
  • step S25 end surface polishing step
  • step S26 second lapping step
  • step S27 polishing step
  • step S28 cleaning process
  • Patent Document 2 As a method for manufacturing a glass substrate for a magnetic disk according to another conventional technique (for example, Patent Document 2), an adhesive is coated on a glass substrate having a constant thickness whose surface is polished, and several tens of glass substrates are obtained. A laminated body is formed by superimposing (stacking step). Next, the inner periphery and outer periphery of the laminated body are processed with a core drill to form a cylindrical body (coring step).
  • the inner peripheral end surface and the outer peripheral end surface of the cylindrical body are polished with a grinding tool to improve the roundness, concentricity, and surface roughness of the outer inner peripheral end surface (end surface grinding step). Then, the edge part of the inner peripheral end surface and outer peripheral end surface of a cylindrical body is chamfered by immersing the cylindrical body which grind
  • the adhesive is melted by being immersed in a dissolution tank, and separated into a chamfered donut-shaped glass substrate (separation step).
  • the separated glass substrate is washed and dried to produce a magnetic disk glass substrate (cleaning step).
  • JP 2003-63831 A Japanese Patent Laid-Open No. 11-219521
  • the former and the latter conventional techniques have a problem that the number of processes is large and the time required for production is long because the two processes of the coring process and the end face grinding process are performed separately.
  • the present invention solves the above-described problem.
  • the coring process and the end face grinding process are performed in one process, the number of processes is reduced, and the time required for manufacturing can be shortened. It aims at providing the manufacturing method of a glass substrate.
  • a first embodiment of the present invention is a magnetic disk in which a circular drilling tool is formed in a circular shape in the glass substrate by allowing the axial drilling tool to pass through while rotating relative to the glass substrate.
  • a preparation step of preparing the drilling tool having an outer diameter of an axis smaller than an inner diameter of the through-hole to be formed in the glass substrate, and the drilling with respect to the center of the through-hole to be formed Arrangement step of shifting the axial center of the tool, relatively rotating the center of the through hole to be formed and the axial center of the drilling tool, and relatively rotating the drilling tool around the axial center
  • the tip end portion of the shaft of the drilling tool forms the through hole in the glass substrate, and the outer peripheral portion of the shaft of the drilling tool is penetrated by the penetrating tool.
  • coring step of grinding the inner peripheral end surface of the hole a method of manufacturing a glass substrate for a
  • the second aspect of the present invention includes a laminating process in which a laminated body is formed by overlapping a plurality of glass substrates with a gap therebetween, and an axial drilling tool is rotated relative to the laminated body.
  • the outer diameter of the shaft is smaller than the inner diameter of the through hole to be formed in the glass substrate.
  • a preparation step of preparing a drilling tool an arrangement step of shifting the axial center of the drilling tool with respect to the center of the through-hole to be formed, the center of the through-hole to be formed and the shaft of the drilling tool By rotating the drilling tool relative to the center and rotating the drilling tool around the axis while rotating the drilling tool relative to the stack.
  • a third aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to either the first aspect or the second aspect, wherein in the preparation step, the outer diameter of the shaft of the drilling tool Is formed to be equal to or larger than the inner radius of the through hole to be formed and smaller than the inner diameter of the through hole, and in the arranging step, the drilling tool is formed with respect to the center of the through hole to be formed.
  • the center of the shaft is shifted by a predetermined amount obtained by subtracting the outer radius of the shaft of the drilling tool from the inner radius of the through hole.
  • a fourth aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to the third aspect, wherein in the preparation step, the outer diameter of the shaft of the drilling tool is set to be larger than the inner diameter of the through hole. It is characterized by being formed from 0.05 mm to 0.1 mm smaller.
  • a fifth aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to either the first aspect or the second aspect, wherein the drilling tool is formed in an axial shape from an iron-based material. It is characterized by.
  • a sixth aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to the fifth aspect, wherein a nickel alloy plating in which diamond particles are mixed is applied to a tip portion of the drilling tool. It is characterized by that.
  • a seventh aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to either the fifth aspect or the sixth aspect, wherein diamond particles are mixed in an outer peripheral portion of the drilling tool. Nickel alloy plating is applied.
  • an eighth aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to either the first aspect or the second aspect, wherein in the coring step, the through hole to be formed is formed.
  • the drilling tool is rotated around the axial center while the glass substrate is rotated around the center.
  • the number of processes is reduced by performing the formation of the circular through hole of the glass substrate and the grinding of the inner peripheral end surface of the circular through hole at a time by the coring process. In this way, the time required for manufacturing can be shortened.
  • a laminated body is formed by superimposing a plurality of sheets, and the laminated body is processed, a plurality of glass substrates can be processed at one time, and production is performed. Improves performance.
  • the outer diameter of the shaft of the drilling tool is set to be equal to or larger than the inner radius of the circular through-hole, the entire through-hole is scraped by the tip portion of the shaft of the drilling tool. The remaining portion is not generated at the center of the hole, and the processing of the remaining portion is not required, and the productivity can be increased.
  • FIG. 1 is a flowchart showing in sequence the steps of manufacturing a magnetic disk glass substrate according to an embodiment of the present invention.
  • FIG. 2 is an explanatory view showing the shape of the drilling tool to be prepared and the arrangement of the drilling tool with respect to the laminated body.
  • Step S01 First, the circular through hole 11 is formed in the glass substrate 10, the inner peripheral end surface 111 of the through hole 11 of the glass substrate 10 is ground, and the outer peripheral end surface 121 of the glass substrate 10 is further ground.
  • a drilling tool 20 and a grinding tool 30 are prepared.
  • the drilling tool 20 is formed as follows.
  • the drilling tool 20 was formed into an axial shape using an iron-based material such as stainless steel.
  • the tip portion 21 (shown in FIG. 4) of the shaft of the drilling tool 20 and the outer peripheral portion 22 were subjected to high hardness alloy plating.
  • the tip portion 21 of the shaft of the drilling tool 20 is a portion for opening the through hole 11 in the glass substrate 10, and the outer peripheral portion 22 is a portion for cutting the inner peripheral end surface 111 of the through hole 11.
  • D be the inner diameter of the through hole 11 to be formed in the glass substrate 10.
  • the outer diameter d of the drilling tool 20 is formed smaller than the inner diameter of the through hole 11 (d ⁇ D).
  • the outer diameter d of the drilling tool 20 is better than the inner radius of the through hole 11 and less than the inner diameter of the through hole 11 (D / 2 ⁇ d ⁇ D). Since the outer diameter d of the drilling tool 20 is greater than or equal to the inner radius of the through-hole 11, no uncut portion is generated at the center of the formed through-hole 11, and processing of the uncut portion becomes unnecessary.
  • the outer diameter d of the drilling tool 20 is smaller than the inner diameter D of the through hole 11 by 0.05 to 1.0 [mm] (D ⁇ 1.0 ⁇ d ⁇ D ⁇ 0). .05).
  • step S02 glass melting step
  • step S03 press molding step S03
  • a glass material is melted (step 01: glass melting step)
  • the molten glass is poured into a planar mold, and the molten glass is sandwiched between the molds and press-molded to produce a disk-shaped glass substrate ( Step 02: Press molding process).
  • the blank material which is a semi-finished glass substrate is produced by this press molding process.
  • the outer diameter D1 of the final glass substrate is 65 mm
  • the outer diameter D1 of the glass substrate 10 is 66 [mm] in the press molding step.
  • the laminate 100 is formed by overlapping a plurality of the press-molded glass substrates (blanks) 10 with a gap. Since the laminated body 100 can be processed at a time in a coring process described later, the productivity of the glass substrate 10 can be improved.
  • a sheet 15 of 0.1 to 0.2 [mm] sandwiched between the glass substrates 10 forms the gap.
  • a relief hole 151 is formed in the sheet 15.
  • An inner diameter D2 of the escape hole 151 is formed larger than an inner diameter D of the through hole 11 to be formed in the glass substrate 10.
  • the outer diameter D3 of the sheet 15 is formed to be smaller than the outer diameter D1 of the glass substrate 10. That is, when polishing the inner peripheral end surface 111 of the through hole 11 and the outer peripheral end surface 121 of the glass substrate 10 in the end surface polishing step, which is a subsequent step of the laminating step, a polishing tool (polishing brush) enters the gap and the inner peripheral end surface.
  • a polishing tool polishing brush
  • polishing tool (polishing brush) does not interfere with the sheet 15 when the edge portion 111 and the edge portion of the outer peripheral end surface 121 are polished.
  • Tool placement process: Step S05 The center of the through hole 11 is Og, and the axial center of the drilling tool 20 is Ot. The axial center Ot of the drilling tool 20 was shifted from the center Og of the through hole 11 by a predetermined amount (offset amount) s.
  • FIG. 4 is an explanatory diagram of the coring process.
  • FIG. 5 is a diagram showing the operation of the drilling tool and the operation of the glass substrate in the coring process.
  • the formation of the through hole 11, the grinding of the inner peripheral end surface 111 of the through hole 11, and the grinding of the outer peripheral end surface 121 of the glass substrate 10 are performed once on the glass substrate (blank material) 10 after press molding. To do.
  • the glass substrate 10 rotates at 10 to 100 [rpm] around the center Og.
  • the drilling tool 20 rotates at 1000 to 10000 [rpm] around the axial center Ot. 5 (a) to 5 (e) show the drilling tool 20 rotated clockwise and the inner peripheral end surface 111 of the through hole 11 of the glass substrate 10 rotated clockwise while contacting the outer peripheral portion 22 of the drilling tool 20. ).
  • FIG. 4 shows the inner peripheral end surface 111 of the through-hole 11 in contact with the outer peripheral portion 22 of the drilling tool 20 and the outer peripheral end surface 121 of the glass substrate 10 in contact with the grinding tool 30.
  • the center Og of the through hole 11 to be formed in the glass substrate 10 and the axis center Ot of the drilling tool 20 were relatively rotated.
  • the glass substrate 10 may be fixed and the axial center Ot of the drilling tool 20 may be rotated with respect to the center Og of the through hole 11 to be formed in the glass substrate 10.
  • the drilling tool 20 may be fixed, and the center Og of the through hole 11 to be formed in the glass substrate 10 may be rotated with respect to the axial center Ot of the drilling tool 20.
  • End face polishing process Step S07
  • the inner peripheral end surface 111 of the through hole 11 of the glass substrate 10 and the outer peripheral end surface 121 of the glass substrate 10 are further polished with a polishing tool (not shown). Thereby, the mirroring of the end surface is performed.
  • chamfering of the edge portion of the inner peripheral end surface 111 and the edge portion of the outer peripheral end surface 121 is also performed.
  • Step S08, lapping: step S09 The laminated body 100 whose end face is ground is separated into glass substrates 10.
  • the glass substrate 10 whose end face is polished is ground on both surfaces, and the parallelism, flatness, and thickness of the glass substrate 10 are finely adjusted.
  • the glass substrate 10 with finely adjusted parallelism or the like is polished on both surfaces, and the surface unevenness is made uniform.
  • the polished glass substrate 10 is cleaned, further inspected, and the passed glass substrate 10 is used as a substrate for a magnetic recording medium.
  • the formation of the through hole 11 of the glass substrate 10 and the grinding of the inner peripheral end surface 111 of the through hole 11 of the glass substrate 10 are performed. Since the outer peripheral end surface 121 of the glass substrate 10 is ground at once, the time required for manufacturing can be shortened.
  • the axial center Ot of the drilling tool 20 is shifted by a predetermined amount (offset amount) s with respect to the center Og of the through hole 11 to be formed in the glass substrate 10, and the predetermined amount s is constant.
  • the present invention is not limited to this.
  • the predetermined amount s may be changed according to the decrease amount. Thereby, the lifetime of the drilling tool 20 can be extended.
  • Example 1 First, Example 1 will be described.
  • Example 1 The dimensions of the glass substrate (blank material) after press forming used in Example 1 are shown below.
  • an amorphous substrate of borosilicate glass was used.
  • the drilling tool 20 was formed into an axial shape using an iron-based material such as stainless steel.
  • the tip portion 21 and the outer peripheral portion 22 of the shaft of the drilling tool 20 were plated with nickel alloy mixed with diamond particles.
  • the axial length of the drilling tool 20 was set to 25 [mm].
  • the outer diameter d of the shaft of the drilling tool 20 was 19.01 [mm].
  • a predetermined amount (offset amount) s 0.45 [mm] was set so as to satisfy the above formula (1).
  • s 0.45 [mm].
  • the through hole 11 is formed in the glass substrate 10
  • the inner peripheral end surface 111 of the through hole 11 is ground
  • the outer peripheral end surface 121 of the glass substrate 10 is ground.
  • Polishing machine USB-1 type glass substrate 10 manufactured by Shoda Techtron Co., Ltd. Rotation speed: 30 rpm Number of rotations of the drilling tool 20: 3000 rpm Number of laminated sheets: 100 sheets The time required for the coring process and the inner diameter were measured under the above conditions.
  • Example 2 Next, Example 2 will be described.
  • the dimensions and the like of the glass substrate (blanks material) after press molding used in Example 2 are the same as those of the glass substrate (blanks material) used in Example 1. (Preparation process)
  • the inner diameter D of the through hole 11 to be formed in the glass substrate 10 was 19.95 [mm].
  • the drilling tool 20 was formed into an axial shape using an iron-based material such as stainless steel.
  • the tip portion 21 and the outer peripheral portion 22 of the shaft of the drilling tool 20 were plated with nickel alloy mixed with diamond particles.
  • the axial length of the drilling tool 20 was set to 25 [mm].
  • the outer diameter d of the shaft of the drilling tool was set to 19.85 [mm].
  • a predetermined amount (offset amount) s 0.05 [mm] was set so as to satisfy the above formula (1).
  • the through hole 11 is formed in the glass substrate 10 by the drilling tool 20, the inner peripheral end surface 111 of the through hole 11 is ground, and the outer peripheral end surface 121 of the glass substrate 10 is ground.
  • Polishing machine USB-1 type glass substrate 10 manufactured by Shoda Techtron Co., Ltd. Rotation speed: 30 rpm Number of rotations of the drilling tool 20: 3000 rpm Number of laminated sheets: 100 sheets The time required for the coring process and the inner diameter were measured under the above conditions.
  • Example 3 Next, Example 3 will be described.
  • the dimensions and the like of the glass substrate (blanks material) after press forming used in Example 3 are the same as those of the glass substrate (blanks material) used in Example 1.
  • the inner diameter D of the through hole 11 to be formed in the glass substrate 10 was 19.95 [mm].
  • the drilling tool 20 was formed into an axial shape using an iron-based material such as stainless steel. Nickel alloy plating mixed with diamond particles was applied to the tip and outer periphery of the shaft of the drilling tool 20.
  • the axial length of the drilling tool 20 was set to 25 [mm].
  • the outer diameter d of the shaft of the drilling tool was set to 17.950 [mm].
  • a predetermined amount (offset amount) s 1.0 [mm] was set so as to satisfy the above formula (1).
  • the through hole 11 is formed in the glass substrate 10 by the drilling tool 20, the inner peripheral end surface 111 of the through hole 11 is ground, and the outer peripheral end surface 121 of the glass substrate 10 is ground.
  • Polishing machine USB-1 type glass substrate 10 manufactured by Shoda Techtron Co., Ltd. Rotation speed: 30 rpm Number of rotations of the drilling tool 20: 3000 rpm Number of laminated sheets: 100 sheets The time required for the coring process and the inner diameter were measured under the above conditions.
  • the dimension etc. of the glass substrate (blanks material) after the press molding used for the comparative example are the same as the glass substrate (blanks material) used in Example 1. (Preparation process)
  • the inner diameter D of the through hole 11 to be formed in the glass substrate 10 was 19.95 [mm].
  • the drilling tool 20 was formed into an axial shape using an iron-based material such as stainless steel.
  • the tip of the shaft of the drilling tool 20 was plated with nickel alloy mixed with diamond particles.
  • the outer diameter d of the shaft of the drilling tool was set to 18.3 [mm].
  • Tool placement process The center Og of the through hole 11 to be formed in the glass substrate 10 and the axial center Ot of the drilling tool 20 were made to coincide.
  • the predetermined amount (offset amount) s 0.
  • the time required for the coring process was 15 minutes. Further, the average inner diameter dimension was 18.45 [mm] and the standard deviation was 0.135 mm, and sufficient accuracy could not be obtained. In addition, a lot of minute chips were generated around the periphery. (End grinding process) The end surface of each glass substrate 10 is ground to the laminated body 100 subjected to the coring.
  • the time required for the end grinding process was 23 minutes. Also, the inner diameter dimension averaged 19.948 [mm] and the standard deviation was 0.00075 [mm], and sufficient accuracy was obtained.
  • Examples 1 to 3 and the comparative example are summarized.
  • the formation of the through hole 11 and the inner peripheral end surface 111 of the through hole 11 are compared with the comparative example.
  • the time required for grinding and grinding of the outer peripheral end face 121 of the glass substrate 10 could be shortened.
  • borosilicate glass was used as the type of glass, but the same results as in the above examples and comparative examples can be obtained using other glass substrates. For example, even when lithium silicate glass or aluminosilicate glass is used, the same effects as those of the above examples and comparative examples can be obtained.

Abstract

Provided is a method of producing a glass substrate for a magnetic disk whereby time required for production can be shortened by decreasing the number of production steps.  The method of producing a glass substrate for a magnetic disk whereby a circular through hole is bored through a glass substrate by making a boring tool in the shape of a shaft penetrate the glass substrate while being rotated relatively thereto, the method comprising a step for providing a boring tool having a shaft with an outside diameter smaller than the inside diameter of a through hole to be bored through the glass substrate, a step for locating the boring tool while shifting the center of the shaft from the center of the through hole to be bored, and a coring step for boring the through hole through the glass substrate using the distal end portion of the shaft of the boring tool and for grinding the inner circumferential end face of the through hole using the outer circumferential portion of the shaft of the boring tool by rotating the center of the through hole to be bored and the center of the shaft of the boring tool relative to each other, and by making the boring tool penetrate the glass substrate while rotating the boring tool relatively about the center of the shaft.

Description

磁気ディスク用ガラス基板の製造方法Manufacturing method of glass substrate for magnetic disk
　この発明は、磁気ディスク記録装置の基板に用いられる磁気ディスク用ガラス基板の製造方法に関する。 The present invention relates to a method of manufacturing a glass substrate for a magnetic disk used for a substrate of a magnetic disk recording apparatus.
　コンピュータ等に用いられる磁気ディスク記録装置、例えばハードディスクには、アルミニウム合金又はガラスのディスクが基板として用いられている。この基板上に金属磁気薄膜が形成され、金属磁気薄膜を磁気ヘッドで磁化することにより情報が記録される。 In a magnetic disk recording device used for a computer or the like, for example, a hard disk, an aluminum alloy or glass disk is used as a substrate. A metal magnetic thin film is formed on this substrate, and information is recorded by magnetizing the metal magnetic thin film with a magnetic head.
　磁気記録媒体用の基板として、従来は、主にアルミニウム合金が用いられていた。しかし、近年は、ノート型パソコン等の携帯型の端末にも磁気ディスク記録装置が採用されており、また、磁気ディスク記録装置の応答速度を高めるために、磁気記録媒体を１００００［ｒｐｍ］以上で高速回転させる必要がある。そのため、高強度な磁気記録媒体用の基板が必要とされてきており、これらの必要性をみたすものとしてガラス基板が用いられるようになった。このガラス基板には、アモルファスガラス基板、結晶化ガラス基板、又は化学強化ガラス基板が用いられている。 Conventionally, aluminum alloys have been mainly used as substrates for magnetic recording media. However, in recent years, magnetic disk recording devices have also been adopted in portable terminals such as notebook computers, and in order to increase the response speed of magnetic disk recording devices, magnetic recording media can be used at 10,000 [rpm] or more. Need to rotate at high speed. For this reason, a substrate for a high-strength magnetic recording medium has been required, and a glass substrate has been used to meet these needs. As this glass substrate, an amorphous glass substrate, a crystallized glass substrate, or a chemically strengthened glass substrate is used.
　ここで、従来技術（例えば特許文献１）に係る磁気記録媒体用ガラス基板の製造方法について、図６を参照にして説明する。図６は、従来技術に係る磁気記録媒体用ガラス基板の製造工程を順番に示すフローチャートである。 Here, a method for manufacturing a glass substrate for a magnetic recording medium according to a conventional technique (for example, Patent Document 1) will be described with reference to FIG. FIG. 6 is a flowchart showing in sequence the manufacturing process of the glass substrate for magnetic recording media according to the prior art.
　はじめに、ガラス素材を溶融し（ステップＳ２０：ガラス溶融工程）、溶融したガラスを平面形状の金型に流し込み、その金型で溶融ガラスを挟むことによりプレス成形し、円盤形状のガラス基板を作製する（ステップＳ２１：プレス成形工程）。このプレス成形工程により作製され、以下に示す研削・研磨工程が施される前段階の半製品のガラス基板を「ブランクス材」と称する。そのブランクス材の表面の中心部にダイヤモンドコアドリルを用いて円状の貫通孔を形成し、ドーナツ状のガラス基板（孔あきブランクス材）を作製する（ステップＳ２２：コアリング工程）。 First, a glass material is melted (step S20: glass melting step), the molten glass is poured into a planar mold, the molten glass is sandwiched between the molds, and press-molded to produce a disk-shaped glass substrate. (Step S21: Press molding process). A glass substrate that is a semi-finished product that is produced by this press molding process and is subjected to the grinding / polishing process described below is referred to as a “blank material”. A circular through hole is formed at the center of the surface of the blank material using a diamond core drill to produce a donut-shaped glass substrate (perforated blank material) (step S22: coring step).
　その後、ダイヤモンドペレットを貼り付けたプレートを保持した両面研磨機にて、ドーナツ状のガラス基板（孔あきブランクス材）を研磨加工する（ステップＳ２３：第１ラッピング工程）。この第１ラッピング工程では、孔あきブランクス材の両表面を研削加工し、ガラス基板の平行度、平坦度、及び厚さを予備調整する。 Then, a doughnut-shaped glass substrate (perforated blanks material) is polished by a double-side polishing machine holding a plate with diamond pellets attached (step S23: first lapping step). In this first lapping step, both surfaces of the perforated blanks are ground and the parallelism, flatness and thickness of the glass substrate are preliminarily adjusted.
　平行度等が予備調整されたガラス基板は、外周端面、孔の内周端面が研削され、ガラス基板の外径寸法及び真円度、並びに孔の内径寸法等が微調整される（ステップＳ２４：端面研削工程）。 In the glass substrate whose parallelism and the like are preliminarily adjusted, the outer peripheral end surface and the inner peripheral end surface of the hole are ground, and the outer diameter size and roundness of the glass substrate, the inner diameter size of the hole, and the like are finely adjusted (step S24: End grinding process).
　外径寸法等が微調整されたガラス基板は、外周端面及び内周端面が研磨され、端面の鏡面化が行われる（ステップＳ２５：端面研磨工程）。端面が研磨されたガラス基板は両表面を再度、研削加工され、ガラス基板の平行度、平坦度、及び厚さが微調整される（ステップＳ２６：第２ラッピング工程）。平行度等が微調整されたガラス基板は、両表面が研磨され、表面の凹凸が均一にされる（ステップＳ２７：ポリッシング工程）。ポリッシング加工されたガラス基板は洗浄され（ステップＳ２８：洗浄工程）、さらに、検査されて、合格したガラス基板が、磁気記録媒体用の基板として用いられる。 The glass substrate whose outer diameter is finely adjusted, the outer peripheral end surface and the inner peripheral end surface are polished, and the end surface is mirror-finished (step S25: end surface polishing step). The glass substrate whose end face is polished is ground again on both surfaces, and the parallelism, flatness, and thickness of the glass substrate are finely adjusted (step S26: second lapping step). The glass substrate whose degree of parallelism and the like is finely adjusted has both surfaces polished to make the surface unevenness uniform (step S27: polishing step). The polished glass substrate is cleaned (step S28: cleaning process), and further, the glass substrate that has been inspected and passed is used as a substrate for a magnetic recording medium.
　また、他の従来技術（例えば特許文献２）に係る磁気ディスク用ガラス基板の製造方法としては、表面が研磨仕上げされた厚さ一定のガラス基板に接着剤を被覆し、数十枚のガラス基板を重ね合わせることにより積層体を形成する（積層工程）。次に、その積層体の内周及び外周をコアドリルにより加工することにより筒状体にする（コアリング工程）。 In addition, as a method for manufacturing a glass substrate for a magnetic disk according to another conventional technique (for example, Patent Document 2), an adhesive is coated on a glass substrate having a constant thickness whose surface is polished, and several tens of glass substrates are obtained. A laminated body is formed by superimposing (stacking step). Next, the inner periphery and outer periphery of the laminated body are processed with a core drill to form a cylindrical body (coring step).
　次に、筒状体の内周端面及び外周端面を研削ツールにより研磨して、真円度、同心度、及び外内周端面の表面粗さを向上させる（端面研削工程）。その後、内周端面等を研削された筒状体をエッチング槽に所定の時間浸漬することにより、筒状体の内周端面及び外周端面のエッジ部を面取りする（端面処理工程）。 Next, the inner peripheral end surface and the outer peripheral end surface of the cylindrical body are polished with a grinding tool to improve the roundness, concentricity, and surface roughness of the outer inner peripheral end surface (end surface grinding step). Then, the edge part of the inner peripheral end surface and outer peripheral end surface of a cylindrical body is chamfered by immersing the cylindrical body which grind | polished the inner peripheral end surface etc. for the predetermined time in the etching tank (end surface processing process).
　次に、溶解槽に浸漬することにより、接着剤を溶かし、面取りされたドーナツ状のガラス基板に分離する（分離工程）。その分離されたガラス基板を洗浄し、乾燥して磁気ディスク用ガラス基板を製造する（洗浄工程）。 Next, the adhesive is melted by being immersed in a dissolution tank, and separated into a chamfered donut-shaped glass substrate (separation step). The separated glass substrate is washed and dried to produce a magnetic disk glass substrate (cleaning step).
特開２００３－６３８３１号公報JP 2003-63831 A 特開平１１－２１９５２１号公報Japanese Patent Laid-Open No. 11-219521
　しかしながら、前者及び後者の従来技術では、コアリング工程と、端面研削工程との２つの工程を別々に行うため、工程数が多く、製造に要する時間が長くなるという問題点があった。 However, the former and the latter conventional techniques have a problem that the number of processes is large and the time required for production is long because the two processes of the coring process and the end face grinding process are performed separately.
　この発明は、上記の問題を解決するものであり、コアリング工程と端面研削工程とを１つの工程で行うようにして、工程数を減少させて、製造に要する時間を短縮可能な磁気ディスク用ガラス基板の製造方法を提供することを目的とする。 The present invention solves the above-described problem. For a magnetic disk, the coring process and the end face grinding process are performed in one process, the number of processes is reduced, and the time required for manufacturing can be shortened. It aims at providing the manufacturing method of a glass substrate.
　上記課題を解決するため、この発明の第１の形態は、軸形状の穿孔ツールをガラス基板に対して相対回転させながら貫通させることにより、前記ガラス基板に円形状の貫通孔を形成する磁気ディスク用ガラス基板の製造方法において、前記ガラス基板に形成すべき前記貫通孔の内径より軸の外径が小さい前記穿孔ツールを準備する準備工程と、前記形成すべき貫通孔の中心に対して前記穿孔ツールの軸中心をずらして位置させる配置工程と、前記形成すべき貫通孔の中心と前記穿孔ツールの前記軸中心とを相対的に回転させ、かつ、該軸中心回りに前記穿孔ツールを相対回転させながら、前記ガラス基板に貫通させることにより、前記穿孔ツールの軸の先端部が前記ガラス基板に前記貫通孔を形成し、前記穿孔ツールの軸の外周部が前記貫通孔の内周端面を研削するコアリング工程と、を有することを特徴とする磁気ディスク用ガラス基板の製造方法である。 In order to solve the above-mentioned problem, a first embodiment of the present invention is a magnetic disk in which a circular drilling tool is formed in a circular shape in the glass substrate by allowing the axial drilling tool to pass through while rotating relative to the glass substrate. In the method for manufacturing a glass substrate for use, a preparation step of preparing the drilling tool having an outer diameter of an axis smaller than an inner diameter of the through-hole to be formed in the glass substrate, and the drilling with respect to the center of the through-hole to be formed Arrangement step of shifting the axial center of the tool, relatively rotating the center of the through hole to be formed and the axial center of the drilling tool, and relatively rotating the drilling tool around the axial center However, by penetrating through the glass substrate, the tip end portion of the shaft of the drilling tool forms the through hole in the glass substrate, and the outer peripheral portion of the shaft of the drilling tool is penetrated by the penetrating tool. And coring step of grinding the inner peripheral end surface of the hole, a method of manufacturing a glass substrate for a magnetic disk and having a.
　また、この発明の第２の形態は、複数枚のガラス基板を隙間をおいて重ね合わせることにより積層体を形成する積層工程を有し、軸形状の穿孔ツールを前記積層体に対して相対回転させながら貫通させることにより、前記各ガラス基板に円形状の貫通孔を形成する磁気ディスク用ガラス基板の製造方法において、前記ガラス基板に形成すべき前記貫通孔の内径より軸の外径が小さい前記穿孔ツールを準備する準備工程と、前記形成すべき貫通孔の中心に対して前記穿孔ツールの軸中心をずらして位置させる配置工程と、前記形成すべき貫通孔の中心と前記穿孔ツールの前記軸中心とを相対的に回転させ、かつ、該軸中心回りに前記穿孔ツールを前記積層体に対して相対回転させながら前記積層体に貫通させることにより、前記穿孔ツールの軸の先端部が前記各ガラス基板に前記貫通孔を形成し、前記穿孔ツールの軸の外周部が前記各ガラス基板の貫通孔の内周端面を研削するコアリング工程と、を有することを特徴とする磁気ディスク用ガラス基板の製造方法である。 The second aspect of the present invention includes a laminating process in which a laminated body is formed by overlapping a plurality of glass substrates with a gap therebetween, and an axial drilling tool is rotated relative to the laminated body. In the method for manufacturing a glass substrate for a magnetic disk in which a circular through hole is formed in each glass substrate by passing through the glass substrate, the outer diameter of the shaft is smaller than the inner diameter of the through hole to be formed in the glass substrate. A preparation step of preparing a drilling tool, an arrangement step of shifting the axial center of the drilling tool with respect to the center of the through-hole to be formed, the center of the through-hole to be formed and the shaft of the drilling tool By rotating the drilling tool relative to the center and rotating the drilling tool around the axis while rotating the drilling tool relative to the stack. A coring step in which the front end portion of the glass substrate forms the through hole in each glass substrate, and the outer peripheral portion of the shaft of the drilling tool grinds the inner peripheral end surface of the through hole of each glass substrate. This is a method for manufacturing a glass substrate for a magnetic disk.
　さらに、この発明の第３の形態は、第１の形態又は第２の形態のいずれかに係る磁気ディスク用ガラス基板の製造方法であって、前記準備工程において、前記穿孔ツールの軸の外径を、前記形成すべき貫通孔の内半径以上であって、かつ、該貫通孔の内径未満になるように形成し、前記配置工程において、前記形成すべき貫通孔の中心に対して前記穿孔ツールの軸中心を、前記貫通孔の内半径から前記穿孔ツールの軸の外半径を減算させた所定量だけずらして位置させたことを特徴とする。 Furthermore, a third aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to either the first aspect or the second aspect, wherein in the preparation step, the outer diameter of the shaft of the drilling tool Is formed to be equal to or larger than the inner radius of the through hole to be formed and smaller than the inner diameter of the through hole, and in the arranging step, the drilling tool is formed with respect to the center of the through hole to be formed. The center of the shaft is shifted by a predetermined amount obtained by subtracting the outer radius of the shaft of the drilling tool from the inner radius of the through hole.
　さらに、この発明の第４の形態は、第３の形態に係る磁気ディスク用ガラス基板の製造方法であって、前記準備工程において、前記穿孔ツールの軸の外径を、前記貫通孔の内径より０．０５ｍｍから０．１ｍｍ小さく形成したことを特徴とする。 Furthermore, a fourth aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to the third aspect, wherein in the preparation step, the outer diameter of the shaft of the drilling tool is set to be larger than the inner diameter of the through hole. It is characterized by being formed from 0.05 mm to 0.1 mm smaller.
　さらに、この発明の第５の形態は、第１の形態又は第２の形態のいずれかに係る磁気ディスク用ガラス基板の製造方法であって、前記穿孔ツールは鉄系材料により軸形状に形成されていることを特徴とする。 Furthermore, a fifth aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to either the first aspect or the second aspect, wherein the drilling tool is formed in an axial shape from an iron-based material. It is characterized by.
　さらに、この発明の第６の形態は、第５の形態に係る磁気ディスク用ガラス基板の製造方法であって、前記穿孔ツールの先端部にダイヤモンド粒子が混合されたニッケル合金メッキが施されていることを特徴とする。 Furthermore, a sixth aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to the fifth aspect, wherein a nickel alloy plating in which diamond particles are mixed is applied to a tip portion of the drilling tool. It is characterized by that.
　さらに、この発明の第７の形態は、第５の形態又は第６の形態のいずれかに係る磁気ディスク用ガラス基板の製造方法であって、前記穿孔ツールの外周部にダイヤモンド粒子が混合されたニッケル合金メッキが施されていることを特徴とする。 Furthermore, a seventh aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to either the fifth aspect or the sixth aspect, wherein diamond particles are mixed in an outer peripheral portion of the drilling tool. Nickel alloy plating is applied.
　さらに、この発明の第８の形態は、第１の形態又は第２の形態のいずれかに係る磁気ディスク用ガラス基板の製造方法であって、前記コアリング工程では、前記形成すべき貫通孔の中心を中心にして前記ガラス基板を回転させながら、前記穿孔ツールを前記軸中心を中心にして回転させることを特徴とする。 Furthermore, an eighth aspect of the present invention is a method for manufacturing a glass substrate for a magnetic disk according to either the first aspect or the second aspect, wherein in the coring step, the through hole to be formed is formed. The drilling tool is rotated around the axial center while the glass substrate is rotated around the center.
　この発明の第１の形態によると、コアリング工程により、ガラス基板の円形状の貫通孔の形成と、円形状の貫通孔の内周端面の研削とを一度に行うことにより、工程数を減少させて、製造に要する時間を短縮可能とする。 According to the first embodiment of the present invention, the number of processes is reduced by performing the formation of the circular through hole of the glass substrate and the grinding of the inner peripheral end surface of the circular through hole at a time by the coring process. In this way, the time required for manufacturing can be shortened.
　また、この発明の第２の形態によると、複数枚を重ね合わせることにより積層体を形成し、積層体に加工を施したので、複数枚のガラス基板の加工を一度に行うことができ、生産性の向上を可能とする。 In addition, according to the second embodiment of the present invention, since a laminated body is formed by superimposing a plurality of sheets, and the laminated body is processed, a plurality of glass substrates can be processed at one time, and production is performed. Improves performance.
　さらに、この発明の第３の形態によると、穿孔ツールの軸の外径を円形状の貫通孔の内半径以上としたので、穿孔ツールの軸の先端部により貫通孔の全部が削れるので、貫通孔の中心部に削り残り部が発生せず、削り残り部の処理を不要とし、生産性を上げることが可能となる。 Furthermore, according to the third aspect of the present invention, since the outer diameter of the shaft of the drilling tool is set to be equal to or larger than the inner radius of the circular through-hole, the entire through-hole is scraped by the tip portion of the shaft of the drilling tool. The remaining portion is not generated at the center of the hole, and the processing of the remaining portion is not required, and the productivity can be increased.
　さらに、この発明の第４の形態によると、貫通孔の中心と穿孔ツールの軸中心とを相対的に回転させるとき、軸中心の少ない相対移動に対し、大きな回転量を得ることが可能となる。 Furthermore, according to the fourth aspect of the present invention, when the center of the through hole and the shaft center of the drilling tool are relatively rotated, a large amount of rotation can be obtained with respect to relative movement with a small shaft center. .
この発明の一実施形態に係る磁気ディスク用ガラス基板の製造工程を順番に示すフローチャートである。It is a flowchart which shows in order the manufacturing process of the glass substrate for magnetic discs which concerns on one Embodiment of this invention. 準備される穿孔ツールの形状、及び穿孔ツールの積層体に対する配置を示した説明図である。It is explanatory drawing which showed the shape with respect to the drilling tool prepared, and arrangement | positioning with respect to the laminated body of a drilling tool. 積層工程の説明図である。It is explanatory drawing of a lamination process. コアリング工程の説明図である。It is explanatory drawing of a coring process. コアリング工程における穿孔ツールの動作及びガラス基板の動作を示す図である。It is a figure which shows operation | movement of the drilling tool and operation | movement of a glass substrate in a coring process. 従来技術に係る磁気記録媒体用ガラス基板の製造工程を順番に示すフローチャートである。It is a flowchart which shows the manufacturing process of the glass substrate for magnetic recording media concerning a prior art in order.
　この発明の一実施形態に係る磁気ディスク用ガラス基板の製造方法について図１から図５を参照して説明する。図１は、この発明の一実施形態に係る磁気ディスク用ガラス基板の製造工程を順番に示すフローチャートである。図２は、準備される穿孔ツールの形状、及び穿孔ツールの積層体に対する配置を示した説明図である。以下、図１に示す製造工程の順番に説明する。
（準備工程：ステップＳ０１）
　先ず始めに、ガラス基板１０に円形状の貫通孔１１を形成し、また、ガラス基板１０の貫通孔１１の内周端面１１１を研削し、さらに、ガラス基板１０の外周端面１２１を研削するための穿孔ツール２０と研削ツール３０を準備する。 A method for manufacturing a magnetic disk glass substrate according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a flowchart showing in sequence the steps of manufacturing a magnetic disk glass substrate according to an embodiment of the present invention. FIG. 2 is an explanatory view showing the shape of the drilling tool to be prepared and the arrangement of the drilling tool with respect to the laminated body. Hereinafter, it demonstrates in order of the manufacturing process shown in FIG.
(Preparation process: Step S01)
First, the circular through hole 11 is formed in the glass substrate 10, the inner peripheral end surface 111 of the through hole 11 of the glass substrate 10 is ground, and the outer peripheral end surface 121 of the glass substrate 10 is further ground. A drilling tool 20 and a grinding tool 30 are prepared.
　穿孔ツール２０は、次のように形成される。穿孔ツール２０をステンレス等の鉄系材料により軸形状に形成した。穿孔ツール２０の軸の先端部２１（図４に示す）及び外周部２２に、高硬度の合金メッキを施した。穿孔ツール２０の軸の先端部２１が、ガラス基板１０に貫通孔１１を開ける部分となり、外周部２２が、その貫通孔１１の内周端面１１１を切削する部分となる。ここで、ガラス基板１０に形成すべき貫通孔１１の内径をＤとする。穿孔ツール２０の外径ｄは、貫通孔１１の内径未満に形成される（ｄ＜Ｄ）。 The drilling tool 20 is formed as follows. The drilling tool 20 was formed into an axial shape using an iron-based material such as stainless steel. The tip portion 21 (shown in FIG. 4) of the shaft of the drilling tool 20 and the outer peripheral portion 22 were subjected to high hardness alloy plating. The tip portion 21 of the shaft of the drilling tool 20 is a portion for opening the through hole 11 in the glass substrate 10, and the outer peripheral portion 22 is a portion for cutting the inner peripheral end surface 111 of the through hole 11. Here, let D be the inner diameter of the through hole 11 to be formed in the glass substrate 10. The outer diameter d of the drilling tool 20 is formed smaller than the inner diameter of the through hole 11 (d <D).
　穿孔ツール２０の外径ｄは、貫通孔１１の内半径以上であって、かつ、貫通孔１１の内径未満に形成されるとより良い（Ｄ／２≦ｄ＜Ｄ）。穿孔ツール２０の外径ｄが貫通孔１１の内半径以上あるので、形成される貫通孔１１の中心部に削り残り部が発生せず、削り残り部の処理が不要となる。 The outer diameter d of the drilling tool 20 is better than the inner radius of the through hole 11 and less than the inner diameter of the through hole 11 (D / 2 ≦ d <D). Since the outer diameter d of the drilling tool 20 is greater than or equal to the inner radius of the through-hole 11, no uncut portion is generated at the center of the formed through-hole 11, and processing of the uncut portion becomes unnecessary.
　さらに、好ましくは、穿孔ツール２０の外径ｄは、貫通孔１１の内径Ｄより０．０５～１．０［ｍｍ］だけ小さく形成されると良い（Ｄ－１．０≦ｄ≦Ｄ－０．０５）。 Further, preferably, the outer diameter d of the drilling tool 20 is smaller than the inner diameter D of the through hole 11 by 0.05 to 1.0 [mm] (D−1.0 ≦ d ≦ D−0). .05).
　それにより、貫通孔１１の中心Ｏｇと穿孔ツール２０の軸中心Ｏｔとを相対的に回転させるとき、軸中心Ｏｔの少ない相対移動に対し、大きな回転量を得ることが可能となり、結果的に、貫通孔１１の内周端面１１１を穿孔ツール２０により効率よく切削可能となる。
（ガラス溶融：ステップＳ０２，プレス成形：ステップＳ０３）
　まず、ガラス素材を溶融し（ステップ０１：ガラス溶融工程）、溶融したガラスを平面形状の金型に流し込み、その型で溶融ガラスを挟むことによりプレス成形し、円盤状のガラス基板を作製する（ステップ０２：プレス成形工程）。このプレス成形工程により、半製品のガラス基板であるブランクス材が作製される。 Thereby, when the center Og of the through hole 11 and the axis center Ot of the drilling tool 20 are relatively rotated, it is possible to obtain a large amount of rotation with respect to a relative movement with a small axis center Ot. The inner peripheral end surface 111 of the through hole 11 can be efficiently cut by the drilling tool 20.
(Glass melting: step S02, press molding: step S03)
First, a glass material is melted (step 01: glass melting step), the molten glass is poured into a planar mold, and the molten glass is sandwiched between the molds and press-molded to produce a disk-shaped glass substrate ( Step 02: Press molding process). The blank material which is a semi-finished glass substrate is produced by this press molding process.
　この実施形態では、最終製品のガラス基板の外径Ｄ１＝６５ｍｍとした場合、上記プレス成形工程では、ガラス基板１０の外径Ｄ１＝６６［ｍｍ］に形成される。なお、ガラス基板１０の板厚＝１．０［ｍｍ］に成形される。
（積層工程：ステップＳ０４）
　次に、積層工程について図３を参照にして説明する。図３は、積層工程の説明図である。 In this embodiment, when the outer diameter D1 of the final glass substrate is 65 mm, the outer diameter D1 of the glass substrate 10 is 66 [mm] in the press molding step. The glass substrate 10 is formed to have a thickness = 1.0 [mm].
(Lamination process: Step S04)
Next, the lamination process will be described with reference to FIG. FIG. 3 is an explanatory diagram of the stacking process.
　上記プレス成形されたガラス基板（ブランクス材）１０を、隙間をおいて複数枚重ね合わせることにより積層体１００が形成される。後述するコアリング工程において、積層体１００を一度に加工できるので、ガラス基板１０の生産性を向上させることが可能となる。 The laminate 100 is formed by overlapping a plurality of the press-molded glass substrates (blanks) 10 with a gap. Since the laminated body 100 can be processed at a time in a coring process described later, the productivity of the glass substrate 10 can be improved.
　ガラス基板１０に挟まれた０．１～０．２［ｍｍ］のシート１５が前記隙間を形成する。シート１５には逃げ孔１５１が形成されている。逃げ孔１５１の内径Ｄ２は、ガラス基板１０に形成すべき貫通孔１１の内径Ｄより大きめに形成されている。また、シート１５の外径Ｄ３は、ガラス基板１０の外径Ｄ１より小さめに形成されている。それは、積層工程の後工程である端面研磨工程において、貫通孔１１の内周端面１１１及びガラス基板１０の外周端面１２１を研磨する場合、研磨ツール（研磨ブラシ）が前記隙間に入って内周端面１１１のエッジ部及び外周端面１２１のエッジ部を研磨するときに、研磨ツール（研磨ブラシ）をシート１５と干渉させないためである。
（ツール配置工程：ステップＳ０５）
　貫通孔１１の中心をＯｇとし、穿孔ツール２０の軸中心をＯｔとする。貫通孔１１の中心Ｏｇに対して穿孔ツール２０の軸中心Ｏｔを所定量（オフセット量）ｓずらして位置させた。 A sheet 15 of 0.1 to 0.2 [mm] sandwiched between the glass substrates 10 forms the gap. A relief hole 151 is formed in the sheet 15. An inner diameter D2 of the escape hole 151 is formed larger than an inner diameter D of the through hole 11 to be formed in the glass substrate 10. Further, the outer diameter D3 of the sheet 15 is formed to be smaller than the outer diameter D1 of the glass substrate 10. That is, when polishing the inner peripheral end surface 111 of the through hole 11 and the outer peripheral end surface 121 of the glass substrate 10 in the end surface polishing step, which is a subsequent step of the laminating step, a polishing tool (polishing brush) enters the gap and the inner peripheral end surface. This is because the polishing tool (polishing brush) does not interfere with the sheet 15 when the edge portion 111 and the edge portion of the outer peripheral end surface 121 are polished.
(Tool placement process: Step S05)
The center of the through hole 11 is Og, and the axial center of the drilling tool 20 is Ot. The axial center Ot of the drilling tool 20 was shifted from the center Og of the through hole 11 by a predetermined amount (offset amount) s.
　貫通孔１１の内半径Ｒ、穿孔ツール２０の外半径ｒ、及び所定量（オフセット量）ｓの関係を、次の式（１）で表すことができる。 The relationship between the inner radius R of the through-hole 11, the outer radius r of the drilling tool 20, and the predetermined amount (offset amount) s can be expressed by the following equation (1).
　　Ｒ≧ｒ＋ｓ　　…（１）
　上記の準備工程で示したように、穿孔ツール２０の外径ｄが、貫通孔１１の内径Ｄより０．０５～１．０［ｍｍ］だけ小さく形成される場合（Ｄ－１．０≦ｄ≦Ｄ－０．０５）、所定量（オフセット量）ｓ＝０．０２５～０．５［ｍｍ］となる。
（コアリング工程：ステップＳ０６）
　次に、コアリング工程について図４及び図５を参照にして説明する。図４は、コアリング工程の説明図である。図５は、コアリング工程における穿孔ツールの動作及びガラス基板の動作を示す図である。 R ≧ r + s (1)
As shown in the above preparation process, when the outer diameter d of the drilling tool 20 is formed smaller than the inner diameter D of the through hole 11 by 0.05 to 1.0 [mm] (D−1.0 ≦ d ≦ D−0.05), and a predetermined amount (offset amount) s = 0.025 to 0.5 [mm].
(Coring process: step S06)
Next, the coring process will be described with reference to FIGS. FIG. 4 is an explanatory diagram of the coring process. FIG. 5 is a diagram showing the operation of the drilling tool and the operation of the glass substrate in the coring process.
　コアリング工程において、プレス成形後のガラス基板（ブランクス材）１０に対して貫通孔１１の形成と、貫通孔１１の内周端面１１１の研削と、ガラス基板１０の外周端面１２１の研削とを一度に行う。 In the coring step, the formation of the through hole 11, the grinding of the inner peripheral end surface 111 of the through hole 11, and the grinding of the outer peripheral end surface 121 of the glass substrate 10 are performed once on the glass substrate (blank material) 10 after press molding. To do.
　コアリング工程後のガラス基板１０の外径Ｄ１及び寸法公差は、Ｄ１＝６５±０．１［ｍｍ］である。また、ガラス基板１０の貫通孔１１の内径Ｄ及び寸法公差は、Ｄ＝２０±０．０１［ｍｍ］である。 The outer diameter D1 and dimensional tolerance of the glass substrate 10 after the coring step are D1 = 65 ± 0.1 [mm]. Further, the inner diameter D and the dimensional tolerance of the through hole 11 of the glass substrate 10 are D = 20 ± 0.01 [mm].
　次に、コアリング工程におけるガラス基板１０及び穿孔ツール２０の各動作について説明する。ガラス基板１０は、中心Ｏｇ回りに１０～１００［ｒｐｍ］で回転する。穿孔ツール２０は、軸中心Ｏｔ回りに１０００～１００００［ｒｐｍ］で回転する。時計方向に回転させた穿孔ツール２０と、穿孔ツール２０の外周部２２に接触させながら時計方向に回転させたガラス基板１０の貫通孔１１の内周端面１１１とを図５（ａ）～（ｅ）に示す。 Next, each operation of the glass substrate 10 and the drilling tool 20 in the coring process will be described. The glass substrate 10 rotates at 10 to 100 [rpm] around the center Og. The drilling tool 20 rotates at 1000 to 10000 [rpm] around the axial center Ot. 5 (a) to 5 (e) show the drilling tool 20 rotated clockwise and the inner peripheral end surface 111 of the through hole 11 of the glass substrate 10 rotated clockwise while contacting the outer peripheral portion 22 of the drilling tool 20. ).
　貫通孔１１の内周端面１１１が穿孔ツール２０の外周部２２に接触させることにより、貫通孔１１の内周端面１１１が研削され、貫通孔１１の内径Ｄ＝２０±０．０１［ｍｍ］となる。このとき、ガラス基板１０の外周端面１２１が研削ツール３０により研削され、ガラス基板１０の外径Ｄ１＝６５±０．１［ｍｍ］となる。穿孔ツール２０の外周部２２に接触した貫通孔１１の内周端面１１１、及び、研削ツール３０に接触させたガラス基板１０の外周端面１２１を図４に示す。 By bringing the inner peripheral end surface 111 of the through hole 11 into contact with the outer peripheral portion 22 of the drilling tool 20, the inner peripheral end surface 111 of the through hole 11 is ground, and the inner diameter D of the through hole 11 is 20 ± 0.01 [mm]. Become. At this time, the outer peripheral end surface 121 of the glass substrate 10 is ground by the grinding tool 30, and the outer diameter D1 of the glass substrate 10 becomes 65 ± 0.1 [mm]. FIG. 4 shows the inner peripheral end surface 111 of the through-hole 11 in contact with the outer peripheral portion 22 of the drilling tool 20 and the outer peripheral end surface 121 of the glass substrate 10 in contact with the grinding tool 30.
　なお、図５では、ガラス基板１０と穿孔ツール２０との回転方向が同方向（時計方向）であるものを示したが、互いに反対の方向（時計方向と反時計方向）であっても良い。 In addition, in FIG. 5, although the rotation direction of the glass substrate 10 and the drilling tool 20 showed the same direction (clockwise direction), it may be a mutually opposite direction (clockwise direction and counterclockwise direction).
　以上により、ガラス基板１０に形成すべき貫通孔１１の中心Ｏｇと穿孔ツール２０の軸中心Ｏｔとを相対的に回転させた。これに限らず、例えば、ガラス基板１０を固定し、ガラス基板１０に形成すべき貫通孔１１の中心Ｏｇに対して穿孔ツール２０の軸中心Ｏｔを回転させても良い。一方、穿孔ツール２０を固定し、穿孔ツール２０の軸中心Ｏｔに対して、ガラス基板１０に形成すべき貫通孔１１の中心Ｏｇを回転させても良い。
（端面研磨工程：ステップＳ０７）
　端面研磨工程においては、さらに、ガラス基板１０の貫通孔１１の内周端面１１１及びガラス基板１０の外周端面１２１を研磨ツール（図示省略）により研磨する。それにより、端面の鏡面化が行われる。ここで、内周端面１１１のエッジ部及び外周端面１２１のエッジ部の面取りも行われる。
（分離工程：ステップＳ０８，ラッピング：ステップＳ０９）
　端面が研削された積層体１００を、各ガラス基板１０に分離する。端面が研磨されたガラス基板１０は両表面を研削加工され、ガラス基板１０の平行度、平坦度、及び厚さが微調整される。
（ポリッシング：ステップＳ１０，洗浄：ステップＳ１１）
　平行度等が微調整されたガラス基板１０は、両表面が研磨され、表面の凹凸が均一にされる。ポリッシング加工されたガラス基板１０は洗浄され、さらに、検査されて、合格したガラス基板１０が、磁気記録媒体用の基板として用いられる。 As described above, the center Og of the through hole 11 to be formed in the glass substrate 10 and the axis center Ot of the drilling tool 20 were relatively rotated. For example, the glass substrate 10 may be fixed and the axial center Ot of the drilling tool 20 may be rotated with respect to the center Og of the through hole 11 to be formed in the glass substrate 10. On the other hand, the drilling tool 20 may be fixed, and the center Og of the through hole 11 to be formed in the glass substrate 10 may be rotated with respect to the axial center Ot of the drilling tool 20.
(End face polishing process: Step S07)
In the end surface polishing step, the inner peripheral end surface 111 of the through hole 11 of the glass substrate 10 and the outer peripheral end surface 121 of the glass substrate 10 are further polished with a polishing tool (not shown). Thereby, the mirroring of the end surface is performed. Here, chamfering of the edge portion of the inner peripheral end surface 111 and the edge portion of the outer peripheral end surface 121 is also performed.
(Separation process: step S08, lapping: step S09)
The laminated body 100 whose end face is ground is separated into glass substrates 10. The glass substrate 10 whose end face is polished is ground on both surfaces, and the parallelism, flatness, and thickness of the glass substrate 10 are finely adjusted.
(Polishing: Step S10, Cleaning: Step S11)
The glass substrate 10 with finely adjusted parallelism or the like is polished on both surfaces, and the surface unevenness is made uniform. The polished glass substrate 10 is cleaned, further inspected, and the passed glass substrate 10 is used as a substrate for a magnetic recording medium.
　以上のように、この実施形態に係る磁気記録媒体用ガラス基板の製造方法では、コアリング工程において、ガラス基板１０の貫通孔１１の形成、ガラス基板１０の貫通孔１１の内周端面１１１の研削、及びガラス基板１０の外周端面１２１の研削を一度に行ったので、製造に要する時間を短縮することが可能となる。 As described above, in the method for manufacturing a glass substrate for a magnetic recording medium according to this embodiment, in the coring process, the formation of the through hole 11 of the glass substrate 10 and the grinding of the inner peripheral end surface 111 of the through hole 11 of the glass substrate 10 are performed. Since the outer peripheral end surface 121 of the glass substrate 10 is ground at once, the time required for manufacturing can be shortened.
　なお、実施形態では、コアリング工程において、ガラス基板１０に形成すべき貫通孔１１の中心Ｏｇに対して穿孔ツール２０の軸中心Ｏｔを所定量（オフセット量）ｓずらし、その所定量ｓを一定にしたものを示したが、これに限らない。例えば、穿孔ツール２０の消耗により、穿孔ツール２０の軸の外径が減少したとき、その減少量に応じて、所定量ｓを変更可能としても良い。それにより、穿孔ツール２０の寿命を長くすることができる。 In the embodiment, in the coring step, the axial center Ot of the drilling tool 20 is shifted by a predetermined amount (offset amount) s with respect to the center Og of the through hole 11 to be formed in the glass substrate 10, and the predetermined amount s is constant. However, the present invention is not limited to this. For example, when the outer diameter of the shaft of the drilling tool 20 decreases due to wear of the drilling tool 20, the predetermined amount s may be changed according to the decrease amount. Thereby, the lifetime of the drilling tool 20 can be extended.
　また、コアリング工程において、積層体を一度に加工した場合を示したが、この発明は、積層体１００の加工に限らず、ガラス基板１０を１枚ずつ加工しても良い。この場合においても、コアリング工程で、ガラス基板１０の貫通孔１１の内周端面１１１及びガラス基板の外周端面１２１を研削するので、製造時間の短縮が可能となる。
［実施例］
　次に、上記実施形態の具体的な実施例について説明する。
（実施例１）
　先ず、実施例１について説明する。 Moreover, although the case where the laminated body was processed at once was shown in the coring process, this invention is not limited to the processing of the laminated body 100, and the glass substrates 10 may be processed one by one. Even in this case, since the inner peripheral end surface 111 of the through hole 11 of the glass substrate 10 and the outer peripheral end surface 121 of the glass substrate are ground in the coring step, the manufacturing time can be shortened.
[Example]
Next, specific examples of the above embodiment will be described.
Example 1
First, Example 1 will be described.
　以下に、実施例１に用いたプレス成形後のガラス基板（ブランクス材）の寸法を示す。 The dimensions of the glass substrate (blank material) after press forming used in Example 1 are shown below.
　ガラス基板１０の外径Ｄ１＝６６［ｍｍ］
　ガラス基板１０の厚さ＝１．０［ｍｍ］
　なお、実施例１では、ホウ珪酸ガラスのアモルファス基板を用いた。
（準備工程）
　上記ガラス基板１０の製造に使用される穿孔ツール２０を準備する。準備する穿孔ツール２０の形状を示す。なお、ガラス基板１０に形成すべき貫通孔１１の内径Ｄ＝１９．９５［ｍｍ］とした。貫通孔１１の内半径Ｒ＝Ｄ／２＝９．９７５［ｍｍ］となる。 Outer diameter D1 of glass substrate 10 = 66 [mm]
Thickness of glass substrate 10 = 1.0 [mm]
In Example 1, an amorphous substrate of borosilicate glass was used.
(Preparation process)
A drilling tool 20 used for manufacturing the glass substrate 10 is prepared. The shape of the drilling tool 20 to be prepared is shown. The inner diameter D of the through hole 11 to be formed in the glass substrate 10 was 19.95 [mm]. The inner radius of the through hole 11 is R = D / 2 = 9.975 [mm].
　穿孔ツール２０をステンレス等の鉄系材料により軸形状に形成した。穿孔ツール２０の軸の先端部２１及び外周部２２に、ダイヤモンド粒子が混合されたニッケル合金メッキを施した。穿孔ツール２０の軸長を２５［ｍｍ］とした。穿孔ツール２０の軸の外径ｄ＝１９．０５［ｍｍ］に形成した。穿孔ツール２０の軸の外半径ｒ＝ｄ／２＝９．５２５［ｍｍ］となる。
（ツール配置工程）
　上記の式（１）を満たすように、所定量（オフセット量）ｓ＝０．４５［ｍｍ］とした。ガラス基板１０に形成すべき貫通孔１１の中心Ｏｇに対して、準備した穿孔ツール２０の軸中心Ｏｔを所定量ｓ＝０．４５［ｍｍ］ずらして位置させた。
（コアリング工程）
　この穿孔ツール２０により、ガラス基板１０に貫通孔１１を形成し、貫通孔１１の内周端面１１１を研削し、ガラス基板１０の外周端面１２１を研削する。なお、コアリング工程後のガラス基板１０の外径Ｄ１＝６５．０５［ｍｍ］とした。 The drilling tool 20 was formed into an axial shape using an iron-based material such as stainless steel. The tip portion 21 and the outer peripheral portion 22 of the shaft of the drilling tool 20 were plated with nickel alloy mixed with diamond particles. The axial length of the drilling tool 20 was set to 25 [mm]. The outer diameter d of the shaft of the drilling tool 20 was 19.01 [mm]. The outer radius of the axis of the drilling tool 20 is r = d / 2 = 9.525 [mm].
(Tool placement process)
A predetermined amount (offset amount) s = 0.45 [mm] was set so as to satisfy the above formula (1). The axial center Ot of the prepared drilling tool 20 was shifted from the center Og of the through hole 11 to be formed in the glass substrate 10 by a predetermined amount s = 0.45 [mm].
(Coring process)
With this drilling tool 20, the through hole 11 is formed in the glass substrate 10, the inner peripheral end surface 111 of the through hole 11 is ground, and the outer peripheral end surface 121 of the glass substrate 10 is ground. In addition, it was set as the outer diameter D1 = 65.05 [mm] of the glass substrate 10 after a coring process.
　このコアリング工程における貫通孔１１の形成、貫通孔１１の内周端面１１１の研削、及びガラス基板１０の外周端面１２１の研削の条件を以下に示す。 The conditions for forming the through hole 11 in this coring step, grinding the inner peripheral end surface 111 of the through hole 11, and grinding the outer peripheral end surface 121 of the glass substrate 10 are shown below.
　研磨機：ショーダテクトロン（株）製　ＵＳＢ－１型
　ガラス基板１０の回転数：３０ｒｐｍ
　穿孔ツール２０の回転数：３０００ｒｐｍ
　積層枚数：１００枚
　以上の条件で、コアリング工程に要する時間と内径寸法を計測した。 Polishing machine: USB-1 type glass substrate 10 manufactured by Shoda Techtron Co., Ltd. Rotation speed: 30 rpm
Number of rotations of the drilling tool 20: 3000 rpm
Number of laminated sheets: 100 sheets The time required for the coring process and the inner diameter were measured under the above conditions.
　コアリング工程に要した時間は、１５分となった。また、内径寸法は平均１９．９４５［ｍｍ］、標準偏差０．００１４［ｍｍ］となり、十分な精度を得られた。
（実施例２）
　次に、実施例２について説明する。 The time required for the coring process was 15 minutes. Further, the inner diameter dimension averaged 19.945 [mm] and the standard deviation 0.0014 [mm], and sufficient accuracy was obtained.
(Example 2)
Next, Example 2 will be described.
　実施例２に用いたプレス成形後のガラス基板（ブランクス材）の寸法等は、実施例１に用いたガラス基板（ブランクス材）と同じである。
（準備工程）
　ガラス基板１０に形成すべき貫通孔１１の内径Ｄ＝１９．９５［ｍｍ］とした。貫通孔１１の内半径Ｒ＝Ｄ／２＝９．９７５［ｍｍ］となる。 The dimensions and the like of the glass substrate (blanks material) after press molding used in Example 2 are the same as those of the glass substrate (blanks material) used in Example 1.
(Preparation process)
The inner diameter D of the through hole 11 to be formed in the glass substrate 10 was 19.95 [mm]. The inner radius of the through hole 11 is R = D / 2 = 9.975 [mm].
　穿孔ツール２０をステンレス等の鉄系材料により軸形状に形成した。穿孔ツール２０の軸の先端部２１及び外周部２２に、ダイヤモンド粒子が混合されたニッケル合金メッキを施した。穿孔ツール２０の軸長を２５［ｍｍ］とした。穿孔ツールの軸の外径ｄ＝１９．８５［ｍｍ］に形成した。穿孔ツール２０の軸の外半径ｒ＝ｄ／２＝９．９２５［ｍｍ］となる。
（ツール配置工程）
　上記の式（１）を満たすように、所定量（オフセット量）ｓ＝０．０５［ｍｍ］とした。 The drilling tool 20 was formed into an axial shape using an iron-based material such as stainless steel. The tip portion 21 and the outer peripheral portion 22 of the shaft of the drilling tool 20 were plated with nickel alloy mixed with diamond particles. The axial length of the drilling tool 20 was set to 25 [mm]. The outer diameter d of the shaft of the drilling tool was set to 19.85 [mm]. The outer radius of the axis of the drilling tool 20 is r = d / 2 = 9.925 [mm].
(Tool placement process)
A predetermined amount (offset amount) s = 0.05 [mm] was set so as to satisfy the above formula (1).
　ガラス基板１０に形成すべき貫通孔１１の中心Ｏｇに対して、準備した穿孔ツール２０の軸中心Ｏｔを所定量ｓ＝０．０５［ｍｍ］ずらして位置させた。
（コアリング工程）
　上記穿孔ツール２０により、ガラス基板１０に貫通孔１１を形成し、貫通孔１１の内周端面１１１を研削し、ガラス基板１０の外周端面１２１を研削する。なお、コアリング工程後のガラス基板１０の外径Ｄ１を（Ｄ１＝６５．０５［ｍｍ］）とした。 The axial center Ot of the prepared drilling tool 20 was shifted from the center Og of the through hole 11 to be formed in the glass substrate 10 by a predetermined amount s = 0.05 [mm].
(Coring process)
The through hole 11 is formed in the glass substrate 10 by the drilling tool 20, the inner peripheral end surface 111 of the through hole 11 is ground, and the outer peripheral end surface 121 of the glass substrate 10 is ground. In addition, the outer diameter D1 of the glass substrate 10 after a coring process was set to (D1 = 65.05 [mm]).
　このコアリング工程における貫通孔１１の形成、貫通孔１１の内周端面１１１の研削、及びガラス基板１０の外周端面１２１の研削の条件を以下に示す。 The conditions for forming the through hole 11 in this coring step, grinding the inner peripheral end surface 111 of the through hole 11, and grinding the outer peripheral end surface 121 of the glass substrate 10 are shown below.
　研磨機：ショーダテクトロン（株）製　ＵＳＢ－１型
　ガラス基板１０の回転数：３０ｒｐｍ
　穿孔ツール２０の回転数：３０００ｒｐｍ
　積層枚数：１００枚
　以上の条件で、コアリング工程に要する時間と内径寸法を計測した。 Polishing machine: USB-1 type glass substrate 10 manufactured by Shoda Techtron Co., Ltd. Rotation speed: 30 rpm
Number of rotations of the drilling tool 20: 3000 rpm
Number of laminated sheets: 100 sheets The time required for the coring process and the inner diameter were measured under the above conditions.
　コアリング工程に要した時間は、８分となった。また、内径寸法は平均１９．９４３［ｍｍ］、標準偏差０．０００８［ｍｍ］となり、十分な精度を得られた。
（実施例３）
　次に、実施例３について説明する。 The time required for the coring process was 8 minutes. Further, the inner diameter dimension averaged 19.943 [mm] and the standard deviation 0.0008 [mm], and sufficient accuracy was obtained.
(Example 3)
Next, Example 3 will be described.
　実施例３に用いたプレス成形後のガラス基板（ブランクス材）の寸法等は、実施例１に用いたガラス基板（ブランクス材）と同じである。
（準備工程）
　ガラス基板１０に形成すべき貫通孔１１の内径Ｄ＝１９．９５［ｍｍ］とした。貫通孔１１の内半径Ｒ＝Ｄ／２＝９．９７５［ｍｍ］となる。 The dimensions and the like of the glass substrate (blanks material) after press forming used in Example 3 are the same as those of the glass substrate (blanks material) used in Example 1.
(Preparation process)
The inner diameter D of the through hole 11 to be formed in the glass substrate 10 was 19.95 [mm]. The inner radius of the through hole 11 is R = D / 2 = 9.975 [mm].
　穿孔ツール２０をステンレス等の鉄系材料により軸形状に形成した。穿孔ツール２０の軸の先端部及び外周部に、ダイヤモンド粒子が混合されたニッケル合金メッキを施した。穿孔ツール２０の軸長を２５［ｍｍ］とした。穿孔ツールの軸の外径ｄ＝１７．９５０［ｍｍ］に形成した。穿孔ツール２０の軸の外半径ｒ＝ｄ／２＝８．９７５［ｍｍ］となる。
（ツール配置工程）
　上記の式（１）を満たすように、所定量（オフセット量）ｓ＝１．０［ｍｍ］とした。ガラス基板１０に形成すべき貫通孔１１の中心Ｏｇに対して、準備した穿孔ツール２０の軸中心Ｏｔを所定量ｓ＝１．０［ｍｍ］ずらして位置させた。
（コアリング工程）
　上記穿孔ツール２０により、ガラス基板１０に貫通孔１１を形成し、貫通孔１１の内周端面１１１を研削し、ガラス基板１０の外周端面１２１を研削する。なお、コアリング工程後のガラス基板１０の外径Ｄ１＝６５．０５［ｍｍ］とした。 The drilling tool 20 was formed into an axial shape using an iron-based material such as stainless steel. Nickel alloy plating mixed with diamond particles was applied to the tip and outer periphery of the shaft of the drilling tool 20. The axial length of the drilling tool 20 was set to 25 [mm]. The outer diameter d of the shaft of the drilling tool was set to 17.950 [mm]. The outer radius r of the shaft of the drilling tool 20 is r = d / 2 = 8.975 [mm].
(Tool placement process)
A predetermined amount (offset amount) s = 1.0 [mm] was set so as to satisfy the above formula (1). The axial center Ot of the prepared drilling tool 20 was shifted from the center Og of the through hole 11 to be formed in the glass substrate 10 by a predetermined amount s = 1.0 [mm].
(Coring process)
The through hole 11 is formed in the glass substrate 10 by the drilling tool 20, the inner peripheral end surface 111 of the through hole 11 is ground, and the outer peripheral end surface 121 of the glass substrate 10 is ground. In addition, it was set as the outer diameter D1 = 65.05 [mm] of the glass substrate 10 after a coring process.
　このコアリング工程における貫通孔１１の形成、貫通孔１１の内周端面１１１の研削、及びガラス基板１０の外周端面１２１の研削の条件を以下に示す。 The conditions for forming the through hole 11 in this coring step, grinding the inner peripheral end surface 111 of the through hole 11, and grinding the outer peripheral end surface 121 of the glass substrate 10 are shown below.
　研磨機：ショーダテクトロン（株）製　ＵＳＢ－１型
　ガラス基板１０の回転数：３０ｒｐｍ
　穿孔ツール２０の回転数：３０００ｒｐｍ
　積層枚数：１００枚
　以上の条件で、コアリング工程に要する時間と内径寸法を計測した。 Polishing machine: USB-1 type glass substrate 10 manufactured by Shoda Techtron Co., Ltd. Rotation speed: 30 rpm
Number of rotations of the drilling tool 20: 3000 rpm
Number of laminated sheets: 100 sheets The time required for the coring process and the inner diameter were measured under the above conditions.
　コアリング工程に要した時間は、１１分となった。また、内径寸法は平均１９．９４６［ｍｍ］、標準偏差０．００１４［ｍｍ］となり、十分な精度を得られた。
（比較例）
　次に、上記実施例に対する比較例を説明する。 The time required for the coring process was 11 minutes. Moreover, the average inner diameter dimension was 19.946 [mm] and the standard deviation was 0.0014 [mm], and sufficient accuracy was obtained.
(Comparative example)
Next, a comparative example for the above embodiment will be described.
　比較例に用いたプレス成形後のガラス基板（ブランクス材）の寸法等は、実施例１に用いたガラス基板（ブランクス材）と同じである。
（準備工程）
　ガラス基板１０に形成すべき貫通孔１１の内径Ｄ＝１９．９５［ｍｍ］とした。 The dimension etc. of the glass substrate (blanks material) after the press molding used for the comparative example are the same as the glass substrate (blanks material) used in Example 1.
(Preparation process)
The inner diameter D of the through hole 11 to be formed in the glass substrate 10 was 19.95 [mm].
　穿孔ツール２０をステンレス等の鉄系材料により軸形状に形成した。穿孔ツール２０の軸の先端部に、ダイヤモンド粒子が混合されたニッケル合金メッキを施した。穿孔ツールの軸の外径ｄ＝１８．３［ｍｍ］に形成した。
（ツール配置工程）
　ガラス基板１０に形成すべき貫通孔１１の中心Ｏｇと、穿孔ツール２０の軸中心Ｏｔとを一致させた。所定量（オフセット量）ｓ＝０である。
（コアリング工程）
　上記穿孔ツール２０により、ガラス基板１０に貫通孔１１を形成し、貫通孔１１の内周端面１１１を研削し、ガラス基板１０の外周端面１２１を研削する。なお、コアリング工程後のガラス基板１０の外径Ｄ１＝６５．０５［ｍｍ］とした。 The drilling tool 20 was formed into an axial shape using an iron-based material such as stainless steel. The tip of the shaft of the drilling tool 20 was plated with nickel alloy mixed with diamond particles. The outer diameter d of the shaft of the drilling tool was set to 18.3 [mm].
(Tool placement process)
The center Og of the through hole 11 to be formed in the glass substrate 10 and the axial center Ot of the drilling tool 20 were made to coincide. The predetermined amount (offset amount) s = 0.
(Coring process)
The through hole 11 is formed in the glass substrate 10 by the drilling tool 20, the inner peripheral end surface 111 of the through hole 11 is ground, and the outer peripheral end surface 121 of the glass substrate 10 is ground. In addition, it was set as the outer diameter D1 = 65.05 [mm] of the glass substrate 10 after a coring process.
　このコアリング工程における貫通孔１１の形成、貫通孔１１の内周端面１１１の研削、及びガラス基板１０の外周端面１２１の研削の条件を以下に示す。 The conditions for forming the through hole 11 in this coring step, grinding the inner peripheral end surface 111 of the through hole 11, and grinding the outer peripheral end surface 121 of the glass substrate 10 are shown below.
　研削機：ショーダテクトロン（株）製　ＵＳＢ－１型
　ガラス基板１０の回転数：３０ｒｐｍ
　穿孔ツール２０の回転数：３０００ｒｐｍ
　積層枚数：１００枚
　以上の条件で、コアリング工程に要する時間と内径寸法を計測した。 Grinding machine: USB-1 type glass substrate 10 manufactured by Shoda Techtron Co., Ltd. Rotation speed: 30rpm
Number of rotations of the drilling tool 20: 3000 rpm
Number of laminated sheets: 100 sheets The time required for the coring process and the inner diameter were measured under the above conditions.
　コアリング工程に要した時間は、１５分となった。また、内径寸法は平均１８．４５［ｍｍ］、標準偏差０．１３５ｍｍとなり、十分な精度を得られなかった。また、周囲に微小な欠けを多数生じた。
（端面研削工程）
　上記コアリングをした積層体１００に対し、各ガラス基板１０の端面研削をする。 The time required for the coring process was 15 minutes. Further, the average inner diameter dimension was 18.45 [mm] and the standard deviation was 0.135 mm, and sufficient accuracy could not be obtained. In addition, a lot of minute chips were generated around the periphery.
(End grinding process)
The end surface of each glass substrate 10 is ground to the laminated body 100 subjected to the coring.
　この端面研削工程において、各ガラス基板１０の貫通孔１１の内周端面１１１の研削（エッジ部の面取りを含む）の条件、及びガラス基板１０の外周端面１２１の研削（エッジ部の面取りを含む）の条件を以下に示す。 In this end surface grinding step, conditions for grinding the inner peripheral end surface 111 of the through-hole 11 of each glass substrate 10 (including chamfering of the edge portion) and grinding of the outer peripheral end surface 121 of the glass substrate 10 (including chamfering of the edge portion). The conditions are as follows.
　研削機：豊田工機万能研削盤　ＧＵＰ１０
　研削ツールの回転数：７００ｒｐｍ
　積層枚数：１００枚
　以上の条件で、端面研削工程に要する時間と内径寸法を計測した。 Grinding machine: Toyoda machine universal grinder GUP10
Grinding tool rotation speed: 700rpm
Number of layers: 100 The time required for the end grinding process and the inner diameter were measured under the conditions described above.
　端面研削工程に要する時間は、２３分となった。また内径寸法は平均１９．９４８［ｍｍ］、標準偏差０．０００７５［ｍｍ］となり十分な精度を得られた。 The time required for the end grinding process was 23 minutes. Also, the inner diameter dimension averaged 19.948 [mm] and the standard deviation was 0.00075 [mm], and sufficient accuracy was obtained.
　以上により、比較例において、コアリング工程及び端面研削工程に要した時間は、合計３８分（＝１５分＋２３分）となった。 As described above, in the comparative example, the time required for the coring process and the end face grinding process was 38 minutes in total (= 15 minutes + 23 minutes).
　以上のように、実施例１～実施例３及び比較例の結果をまとめると、実施例１～実施例３では、比較例と比べて、貫通孔１１の形成、貫通孔１１の内周端面１１１の研削、及びガラス基板１０の外周端面１２１の研削に要する時間を短縮することができた。 As described above, the results of Examples 1 to 3 and the comparative example are summarized. In Examples 1 to 3, the formation of the through hole 11 and the inner peripheral end surface 111 of the through hole 11 are compared with the comparative example. The time required for grinding and grinding of the outer peripheral end face 121 of the glass substrate 10 could be shortened.
　なお、前記実施例及び比較例では、ガラスの種類として、ホウ珪酸ガラスを用いたが、それ以外のガラス基板を用いても、上記実施例及び比較例と同じ結果が得られる。例えば、リチウムシリケートガラスやアルミノシリケートガラスを用いても、上記実施例及び比較例と同じ効果を奏することができる。 In the examples and comparative examples, borosilicate glass was used as the type of glass, but the same results as in the above examples and comparative examples can be obtained using other glass substrates. For example, even when lithium silicate glass or aluminosilicate glass is used, the same effects as those of the above examples and comparative examples can be obtained.
　１０　ガラス基板
　１００　積層体
　１１　貫通孔
　１１１　内周端面
　１２１　外周端面
　１５　シート
　１５１　逃げ孔
　２０　穿孔ツール
　２１　穿孔ツールの先端部
　２２　穿孔ツールの外周部
　３０　研削ツール DESCRIPTION OF SYMBOLS 10 Glass substrate 100 Laminated body 11 Through-hole 111 Inner peripheral end surface 121 Outer peripheral end surface 15 Sheet 151 Relief hole 20 Drilling tool 21 The front-end | tip part of a drilling tool 22 The outer peripheral part of a drilling tool 30 Grinding tool

Claims (8)

  1. 　軸形状の穿孔ツールをガラス基板に対して相対回転させながら貫通させることにより、前記ガラス基板に円形状の貫通孔を形成する磁気ディスク用ガラス基板の製造方法において、
    　前記ガラス基板に形成すべき前記貫通孔の内径より軸の外径が小さい前記穿孔ツールを準備する準備工程と、
    　前記形成すべき貫通孔の中心に対して前記穿孔ツールの軸中心をずらして位置させる配置工程と、
    　前記形成すべき貫通孔の中心と前記穿孔ツールの前記軸中心とを相対的に回転させ、かつ、該軸中心回りに前記穿孔ツールを相対回転させながら、前記ガラス基板に貫通させることにより、前記穿孔ツールの軸の先端部が前記ガラス基板に前記貫通孔を形成し、前記穿孔ツールの軸の外周部が前記貫通孔の内周端面を研削するコアリング工程と、
    　を有する
    ことを特徴とする磁気ディスク用ガラス基板の製造方法。     In the method for manufacturing a glass substrate for a magnetic disk for forming a circular through-hole in the glass substrate by penetrating an axial-shaped drilling tool while rotating relative to the glass substrate,
    A preparation step of preparing the drilling tool having an outer diameter of a shaft smaller than an inner diameter of the through-hole to be formed in the glass substrate;
    An arrangement step of shifting the axial center of the drilling tool with respect to the center of the through-hole to be formed;
    By rotating the center of the through-hole to be formed and the axis center of the drilling tool relatively, and passing through the glass substrate while rotating the drilling tool around the axis center relatively, A coring step in which a tip portion of a shaft of a drilling tool forms the through hole in the glass substrate, and an outer peripheral portion of the shaft of the drilling tool grinds an inner peripheral end surface of the through hole;
    A method for producing a glass substrate for a magnetic disk, comprising:
  2. 　複数枚のガラス基板を隙間をおいて重ね合わせることにより積層体を形成する積層工程を有し、軸形状の穿孔ツールを前記積層体に対して相対回転させながら貫通させることにより、前記各ガラス基板に円形状の貫通孔を形成する磁気ディスク用ガラス基板の製造方法において、
    　前記ガラス基板に形成すべき前記貫通孔の内径より軸の外径が小さい前記穿孔ツールを準備する準備工程と、
    　前記形成すべき貫通孔の中心に対して前記穿孔ツールの軸中心をずらして位置させる配置工程と、
    　前記形成すべき貫通孔の中心と前記穿孔ツールの前記軸中心とを相対的に回転させ、かつ、該軸中心回りに前記穿孔ツールを前記積層体に対して相対回転させながら前記積層体に貫通させることにより、前記穿孔ツールの軸の先端部が前記各ガラス基板に前記貫通孔を形成し、前記穿孔ツールの軸の外周部が前記各ガラス基板の貫通孔の内周端面を研削するコアリング工程と、
    　を有する
    　ことを特徴とする磁気ディスク用ガラス基板の製造方法。     Each of the glass substrates has a laminating step of forming a laminate by laminating a plurality of glass substrates with a gap, and the shaft-shaped drilling tool is passed through while rotating relative to the laminate. In the method of manufacturing a glass substrate for a magnetic disk in which a circular through hole is formed,
    A preparation step of preparing the drilling tool having an outer diameter of a shaft smaller than an inner diameter of the through-hole to be formed in the glass substrate;
    An arrangement step of shifting the axial center of the drilling tool with respect to the center of the through-hole to be formed;
    The center of the through hole to be formed and the axis center of the drilling tool are rotated relative to each other, and the drilling tool is passed through the laminate while rotating the drilling tool relative to the stack around the axis center. By doing so, the tip portion of the shaft of the drilling tool forms the through hole in each glass substrate, and the outer peripheral portion of the shaft of the drilling tool grinds the inner peripheral end surface of the through hole of each glass substrate Process,
    A method for producing a glass substrate for a magnetic disk, comprising:
  3. 　前記準備工程において、前記穿孔ツールの軸の外径を、前記形成すべき貫通孔の内半径以上であって、かつ、該貫通孔の内径未満になるように形成し、
    　前記配置工程において、前記形成すべき貫通孔の中心に対して前記穿孔ツールの軸中心を、前記貫通孔の内半径から前記穿孔ツールの軸の外半径を減算させた所定量だけずらして位置させたことを特徴とする請求項１又は請求項２のいずれかに記載の磁気ディスク用ガラス基板の製造方法。     In the preparation step, the outer diameter of the shaft of the drilling tool is formed to be greater than or equal to the inner radius of the through hole to be formed and less than the inner diameter of the through hole,
    In the arranging step, the shaft center of the drilling tool is shifted from the center of the through hole to be formed by a predetermined amount obtained by subtracting the outer radius of the shaft of the drilling tool from the inner radius of the through hole. 3. The method for producing a glass substrate for a magnetic disk according to claim 1, wherein the glass substrate for a magnetic disk is formed.
  4. 　前記準備工程において、前記穿孔ツールの軸の外径を、前記貫通孔の内径より０．０５ｍｍから０．１ｍｍ小さく形成したことを特徴とする請求項３に記載の磁気ディスク用ガラス基板の製造方法。 4. The method of manufacturing a glass substrate for a magnetic disk according to claim 3, wherein in the preparation step, an outer diameter of the shaft of the drilling tool is formed to be 0.05 mm to 0.1 mm smaller than an inner diameter of the through hole. .
  5. 　前記穿孔ツールは鉄系材料により軸形状に形成されていることを特徴とする請求項１又は請求項２のいずれかに記載の磁気ディスク用ガラス基板の製造方法。 3. The method of manufacturing a glass substrate for a magnetic disk according to claim 1, wherein the drilling tool is formed in an axial shape from an iron-based material.
  6. 　前記穿孔ツールの先端部にダイヤモンド粒子が混合されたニッケル合金メッキが施されていることを特徴とする請求項５に記載の磁気ディスク用ガラス基板の製造方法。 6. The method for manufacturing a glass substrate for a magnetic disk according to claim 5, wherein a nickel alloy plating mixed with diamond particles is applied to a tip portion of the drilling tool.
  7. 　前記穿孔ツールの外周部にダイヤモンド粒子が混合されたニッケル合金メッキが施されていることを特徴とする請求項５又は請求項６のいずれかに記載の磁気ディスク用ガラス基板の製造方法。 7. The method for manufacturing a glass substrate for a magnetic disk according to claim 5, wherein nickel alloy plating in which diamond particles are mixed is applied to an outer peripheral portion of the drilling tool.
  8. 　前記コアリング工程では、前記形成すべき貫通孔の中心を中心にして前記ガラス基板を回転させながら、前記穿孔ツールを前記軸中心を中心にして回転させることを特徴とする請求項１又は請求項２のいずれかに記載の磁気ディスク用ガラス基板の製造方法。 The said coring process WHEREIN: While rotating the said glass substrate centering | focusing on the center of the said through-hole which should be formed, the said drilling tool is rotated centering | focusing on the said axial center. 3. A method for producing a glass substrate for a magnetic disk according to any one of 2 above.
PCT/JP2009/065817 2008-10-02 2009-09-10 Method of producing glass substrate for magnetic disk WO2010038595A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105365055A (en) * 2015-11-18 2016-03-02 无锡科诺达电子有限公司 Grinding wheel drill

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008105171A (en) * 2006-09-29 2008-05-08 Hoya Corp Method of manufacturing glass substrate for magnetic disk, glass substrate polishing device for magnetic disk and method of manufacturing magnetic disk
JP2008110444A (en) * 2006-10-31 2008-05-15 Konica Minolta Opto Inc Drill for machining glass substrate for information recording medium
JP2008189479A (en) * 2007-01-31 2008-08-21 Hoya Corp Method for manufacturing glass substrate for magnetic disk, method for manufacturing magnetic disk, magnetic disk, and system for manufacturing glass substrate for magnetic disk

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008105171A (en) * 2006-09-29 2008-05-08 Hoya Corp Method of manufacturing glass substrate for magnetic disk, glass substrate polishing device for magnetic disk and method of manufacturing magnetic disk
JP2008110444A (en) * 2006-10-31 2008-05-15 Konica Minolta Opto Inc Drill for machining glass substrate for information recording medium
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105365055A (en) * 2015-11-18 2016-03-02 无锡科诺达电子有限公司 Grinding wheel drill

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