WO2002004371A1 - Composition de verre, substrat pour support d'enregistrement d'informations, disque magnetique, dispositif d'enregistrement/reproduction d'informations et dispositif a disque magnetique utilisant cette composition - Google Patents

Composition de verre, substrat pour support d'enregistrement d'informations, disque magnetique, dispositif d'enregistrement/reproduction d'informations et dispositif a disque magnetique utilisant cette composition Download PDF

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Publication number
WO2002004371A1
WO2002004371A1 PCT/JP2000/004614 JP0004614W WO0204371A1 WO 2002004371 A1 WO2002004371 A1 WO 2002004371A1 JP 0004614 W JP0004614 W JP 0004614W WO 0204371 A1 WO0204371 A1 WO 0204371A1
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WO
WIPO (PCT)
Prior art keywords
terms
magnetic disk
glass
information recording
glass substrate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2000/004614
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English (en)
Japanese (ja)
Inventor
Takashi Namekawa
Yukio Saito
Takashi Naito
Tetsuo Nakazawa
Hiroki Yamamoto
Tatsumi Hirano
Yuzo Kozono
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Hitachi Ltd
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Hitachi Ltd
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Publication date
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Priority to PCT/JP2000/004614 priority Critical patent/WO2002004371A1/fr
Publication of WO2002004371A1 publication Critical patent/WO2002004371A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00—Glass compositions
    • C03C3/04—Glass compositions containing silica
    • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
    • C03C3/083—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound
    • 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
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
    • G11B5/739—Magnetic recording media substrates
    • G11B5/73911—Inorganic substrates
    • G11B5/73921—Glass or ceramic substrates
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/253—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates

Definitions

  • the present invention relates to a novel glass composition, a substrate for an information recording medium, a magnetic disk, an information recording / reproducing device, and a magnetic disk device using the same.
  • Hei 7-300340 a crystallized glass substrate is used, which precipitates crystals by heat treatment to achieve high strength.
  • a high Young's modulus glass substrate described in Japanese Patent Application Laid-Open No. 11-116627, which is considered to be able to cope with high-speed rotation of a disk, has been proposed.
  • Japanese Patent Application Laid-Open Nos. Hei 9-17154 and Hei 10-83531 describe a gas composition having a specific composition. Vinegar has been disclosed.
  • the rotational speed of the magnetic disk has been increased from the current 400 rpm to the future for a glass substrate with an outer diameter of 2.5 inches and a thickness of 0.635 mm. Requires more than 600 rpm or more. As the rotation speed of the glass substrate is increased, the glass substrate is likely to warp or bend, which causes deterioration of the magnetic characteristics of the magnetic disk drive. Therefore, a glass substrate material with a high Young's modulus is required to reduce the amount of warpage and deflection of the glass substrate.
  • the Young's modulus of the glass substrate must be 90 GPa or more in order to minimize the amount of deflection at a high-speed rotation of 600 rpm or more.
  • the Young's modulus of the above-mentioned chemically strengthened glass is not enough at 70 to 85 GPa, and it is difficult to cope with a high-speed rotation of a magnetic disk exceeding 600 rpm.
  • crystallized glass satisfies 85 to 100 OGPa and Young's modulus to some extent, but the cracking rate under a 500 g load by a Pickers hardness meter is as high as 100% and the toughness is high. Due to its small size, there is a problem in impact resistance to a magnetic head.
  • Japanese Patent Application Laid-Open No. 9-71554 discloses a highly rigid substrate.
  • Japanese Patent Application Laid-Open No. 10-83531 and Japanese Patent Application Laid-Open No. 11-116267 have proposed a glass having a high Young's modulus which is considered to be able to cope with high recording density, that is, high-speed rotation for large capacity recording.
  • This substrate has a Young's modulus of 90 to: L 35 GPa, which is considerably higher than that of a conventional glass substrate, and seems to be satisfactory for high-speed rotation of a magnetic disk.
  • alkaline earth oxides of CaO and MgO are contained in a considerably large amount.
  • An object of the present invention is to provide a glass composition which can sufficiently cope with a high-speed rotation of a magnetic disk and which has excellent impact resistance to a magnetic head, a substrate for an information recording medium using the glass composition, a magnetic disk, An object of the present invention is to provide a recording / reproducing device and a magnetic disk device.
  • the present invention is, in molar ratio, from Sani ⁇ containing 0% 8 ⁇ L in terms of S i 0 2 in terms of 40-80%, 10-3 0% and Na 2 O in terms of becomes possible, 40% to 80% by translated into S i0 2, 10 to 30 percent in terms of Al 2 ⁇ 3, in terms of Na 2 ⁇ to in terms 8-20% and Y 2 0 3 2 it consists Sani ⁇ containing 30%, to contain 2-10% in terms of L i 2 0 in these compositions, further, 4 from 0 to 80% in terms of Si0 2, a 1 2 0 3 in terms of 5-30%, comprises 1-20% in terms of 8-20% ⁇ beauty Li 2 0 in terms of Na 2 0, Sn0 2, Z r 0 25 Ti0 2, ZnO there CaO, MgO, the glass composition characterized by comprising an oxide containing 20% or less in one or more of the total amount in terms of each of ⁇ 10 and 2 0 5.
  • the present invention is (M is the ⁇ group element) M 2 0 3 containing an oxide of one or more in terms of one to 30% in these compositions mentioned above, 20% in terms of Cs 2 ⁇ Below, K 2 2 In terms converted to 10% or less and B 2 03, characterized in that it comprises one or more 20% or less than 20% in a total metric.
  • the magnetic disk of the present invention is a magnetic disk comprising at least a glass substrate and an information recording thin film formed directly or via another layer on the surface of the substrate, wherein the glass substrate has a Young's modulus of 90 to 130 GP. a, the thermal expansion coefficient of 60 ⁇ ; 100x10- 7 / ° C, 500 g Kuradzu click incidence from indentation edge portion during Bidzukasu hardness measurement by load is equal to or less than 50%.
  • the water resistance of the glass measured by JIS-3502 on the glass substrate is 0 to 0.2 mg in terms of alkali elution amount.
  • the above-mentioned glass composition in a specific magnetic disk device or information recording / reproducing apparatus, as a substrate for an information recording medium having an information recording thin film, the above-mentioned glass composition or S in the molar ratio is used.
  • M 2 0 3 (M is ⁇ group element) is 0 30%
  • Ln 2 O 3 Ln is a rare earth element
  • M 2 O 3 (M is 111 eight group elements) is ⁇ 2 0 3 is 0-30%, and 2 0 3 preferably has a 0-30%, La 2 O 3 (Ln is a rare earth element ) Is preferably composed of at least one selected from rare earth oxides of Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. Furthermore, L i 2 ⁇ 0 to 20 mol%, K 2 0 is 0 ⁇ : L 0%, ⁇ 2 0 3 is good to contain 0-20%. Further, Sn0 2, Zr0 2, Ti0 2, ZnO, CaO, MgO, that one or more of NiO and V 2 0 5 is contained 0-20% preferred.
  • the glass substrate has an average particle size of:! ⁇ 3 onm of M 2 0 3 (M is 111 eight group elements) Oyobi 1 ⁇ 2 0 3 (Ln is a rare earth element) it is desirable that the fine particles made of is precipitated.
  • the recording surface roughness Ra of the glass is preferably not more than 2. Onm.
  • the present invention relates to a method of manufacturing a device comprising the steps of: It is preferable that the layer mainly composed of Connoxide has an average particle diameter of 5 to 12 nm and a dispersion (standard deviation / average particle diameter) of 25% or less. Preferably, NaCl-type precipitated crystals are present in this layer.
  • the present invention provides a magnetic disk comprising at least a glass substrate and an information recording thin film formed on the surface of the substrate by directly or via another layer mainly composed of conox oxide, and records or reproduces information.
  • the Young's modulus of the glass substrate is preferably 90 to 13 OGPa, and when measuring the Pickers hardness under a load of 500 g for 15 seconds, The crack occurrence rate from the indentation edge portion is 50% or less, and preferably, the coefficient of thermal expansion is 60 to 100 ⁇ 10 17 /.
  • C It is desirable that the water resistance of the glass measured by JIS-R3502 is from 0 to 0.2 mg in terms of alkali elution amount.
  • a magnetic disk having at least a glass substrate and a magnetic thin film formed on the surface opposite to the glass substrate, directly or via another layer, a layer mainly composed of cobalt oxide, and recording or reproducing information.
  • the glass substrate may be composed of the above-mentioned glass composition or a molar ratio of SiO 2 40-80% and Al 2 O 3 5-30.
  • % Na 2 from 08 to 2 0% Cs 2 0 is 0-20%, ⁇ 2 0 3 0 ⁇ is 111 eight group elements) is 0 to 30% Ln 2 0 3 (Ln is a rare earth element) is 0 Those having 10% are preferred.
  • the present invention resides in a glass substrate for a magnetic disk or an optical disk, wherein the Young's modulus is preferably in the range of 90 to 13 OGPa. If the Young's modulus is less than 9 OGPa, the magnetic disk is 2.5 inches in size and the thickness is 0.635 mm. When the disk is rotated at 600 Orpm, the glass bends and the recording / reproduction as a magnetic recording device becomes insufficient. When the magnetic disk is used, when the magnetic disk using the glass substrate rotates at a high speed exceeding 6000 rpm, minute cracks and the like tend to occur due to a decrease in toughness accompanying high rigidity of the glass substrate.
  • the reason the heat Rise expansion coefficient of the glass substrate in the range of 60 ⁇ 100 X 10- 7 / ° C is the three 2 from the magnetic disk This is to match the coefficient of thermal expansion of the stainless steel supporter that supports the magnetic disk in the magnetic disk drive made of magnetic disks. Furthermore, the reason why the crack occurrence rate from the wedge part of the indentation when measuring Vickers hardness under a load of 500 g was set to 50% or less is that when the crack occurrence rate exceeds 50%, the impact resistance of the magnetic head to the magnetic disk This is because it is difficult for the magnetic disk to be sufficiently satisfied, and furthermore, when the magnetic disk is rotated at 6000 rpm on a 2.5-inch size glass substrate, cracks and cracks tend to occur on the glass substrate.
  • the reason why the water resistance of the glass measured by JIS-R3502 on the above glass substrate is 0.2 mg or less for the glass elution amount is that when the glass elution amount exceeds 0.2 mg, the alkali component is reduced to the surface of the substrate. This has an adverse effect on the information recording thin film (magnetic film) formed directly on the substrate surface and reduces the adhesion with the magnetic film.
  • S i0 2 is a glass forming Sani ⁇ a component that contribute to the mechanical strength and I ⁇ stability, assistant engineer glass manufacturing to glass characteristic temperature increases when greater than 80% as glass components In addition, if it is less than 40%, the glass will be devitrified. For this reason, the content of glass S i0 2 is in the range of 40% to 80%. In particular, 45 to 70% is preferable.
  • a 1 2 0 3 is a component that contributes to mechanical properties and chemical stability such as high hardness and high rigidity, glass characteristic temperature becomes too high it becomes difficult to glass production exceeds 30% as glass components If it is less than 5%, the mechanical strength of the glass decreases. Therefore, the content of glass A 1 2 0 3 is in the range of 5-30%. In a specific glass composition, the content is 10 to 30%.
  • Na 20 is a component that can lower the characteristic temperature of glass. If the glass component exceeds 20%, the chemical stability of the glass deteriorates and the mechanical properties also decrease, and less than 8% In this case, the mechanical strength of the glass decreases. Therefore, the content of the glass N a 2 0 is in the range of 8-20%. Specific glass composition smell 8% to 10%.
  • Cs 2 0 is a component that can lower the characteristic temperature of the glass, the mechanical properties deteriorate with the chemical stability of the glass is deteriorated when it exceeds 20 mol%, the glass component, C s 2 0
  • the glass content is 20% or less, preferably 0.5 to 5%.
  • Y 2 0 3 and L a 2 0 3 is a highly rigid components of the glass, the mechanical properties deteriorate with exceeding 3 0% as a glass component chemical stability of the glass is deteriorated
  • Y 2 0 3 and La 2 0 content of the glass of 3 is preferably 30% or less.
  • the content is 2% or more, more preferably 5% or more, and preferably 20% or less.
  • L i 2 0 is a component that can lower the characteristic temperature of the glass, the mechanical properties deteriorate with the chemical stability of the glass is deteriorated when it exceeds 20 mol%, the glass component, L i 2
  • the glass content of 0 should be 20% or less. 2 to 10% or 1 to 20% for specific glass compositions
  • K 2 0 is a component that can lower the characteristic temperature of the glass, the mechanical properties deteriorate with the chemical stability of the glass is deteriorated when it exceeds 10% as a glass component, kappa 2 0 Glass
  • the content is preferably 10% or less, more preferably 0.5% or more.
  • the beta 2 0 3 is a component that can lower the characteristic temperature of the glass, the mechanical properties deteriorate with the chemical stability of the glass is deteriorated when it exceeds 20% as a glass component, a beta 2 0 3
  • the glass content is preferably at most 20%, more preferably at least 0.5%.
  • the S eta 0 2 contributes to the improvement of the glass solubility lowering the high temperature viscosity
  • Z r 0 2 contributes to the chemical stability of the glass
  • CaO and MgO are components that reduce high-temperature viscosity and improve the solubility of glass.
  • NiO is a component contributing to improving mechanical properties
  • V 2 0 5 is also to improve the solubility of the glass lowering the high temperature viscosity as well.
  • Sn0 2, Zr_ ⁇ 2, Ti_ ⁇ 2 ⁇ ZnO, CaO, Mg_ ⁇ , one or more of NiO and V 2 0 5 is preferably comprised more than 20%. Including N a 2 0 and L i 2 0 It is preferably 0.5 to 10%.
  • the glass of the present invention After mixing a predetermined amount of the glass raw material powder of the above-mentioned glass constituent acid oxide, the mixture was sufficiently stirred and mixed, and melted with stirring using a platinum stirring blade in the air for 10 minutes or more. Processing such as cutting, grinding, polishing, etc., is performed with a glass sprocket to obtain a disk-shaped glass substrate of a predetermined shape. In addition, the obtained plate-shaped glass plate was cut out into a disk shape, and from a semi-molten state, formed into a disk shape using a mold, and lapping and polishing were performed using cerium oxide or the like for precision processing of the surface. Is performed to reduce the surface roughness Ra to 2.0 nm or less.
  • the magnetic disk of the present invention comprises at least a glass substrate and an information recording thin film (magnetic film) formed directly or via another layer on the surface of the substrate.
  • Figure 1 shows a schematic diagram of the cross section. As shown in the figure, the magnetic disk of the present invention has a glass substrate 1, a seed film 2, an intermediate film 3, a magnetic film 4, a protective film 5, and a lubricating film 6 sequentially formed.
  • the seed film 2 is a C0-based metal film
  • the intermediate film 3 is a Cr—Ti-based alloy film
  • the magnetic film 4 is a Co—Cr—Pt-based alloy film.
  • the protective film 5 is a carbon film
  • the seed film 2 is an oxide film mainly composed of cobalt oxide as a film structure of the magnetic recording medium.
  • a magnetic recording medium to which an oxide film containing cobalt oxide as a main component is used as a seed film is an in-plane magnetic recording medium, and the Co alloy used for the magnetic film 4 has a hexagonal crystal structure. .
  • the C0 alloy film has uniaxial anisotropy in which the c-axis is the axis of easy magnetization, it is necessary to orient the c-axis in the plane of the magnetic film. Therefore, in order to orient the Co—Cr—Pt alloy of the magnetic film 4, the seed film 2 and the intermediate film 3 need to be oriented so as to be coaxial with the magnetic film 4.
  • the magnetic disk of the present invention it is preferable to use an oxide mainly composed of cobalt oxide, which is easily oriented, as the shield film 2 formed on the surface of the glass substrate 1 of the present invention.
  • the oxidizing film containing the oxidizing cobalt as a main component In order to sufficiently satisfy the magnetic properties of the conductive film, it is preferable that the average particle size is 5 to 12 nm and the dispersion (standard deviation Z average particle size) is 25% or less. It is preferred that C1-type precipitated crystals exist.
  • the Young's modulus is 90 to 130 GPa, and the crack occurrence rate from the indentation edge portion at the time of measuring the Pickers hardness under a 500 g load is 0 to 50%.
  • FIG. 1 is a schematic diagram of a cross section of a magnetic disk manufactured by the present invention
  • FIG. 2 is a schematic diagram of a magnetic disk device manufactured by the present invention.
  • Tables 1, 3 and 4 show the glass compositions of the present invention, and Table 2 shows the comparative examples (mol%).
  • 200 g of an oxide powder to be a constituent material of each glass shown in the table is blended at a predetermined amount of mol%, and is sufficiently mechanically mixed and put into a platinum crucible. After inserting the platinum crucible into the glass-making furnace, the mixture was heated and melted in air at 160 ° C for 1-2 hours while stirring, the platinum crucible was taken out, and the molten glass was sampled for each property evaluation. It is poured into a graphite 7 70 mm x 10 mm deep board for 20 mm wide x 20 mm deep x 60 mm long and 2.5 inch size substrates.
  • the glass is strained at a temperature higher than the glass transition temperature for about 1 hour, and gradually cooled to room temperature to obtain a glass block.
  • a sample for each property evaluation was processed into a shape required for each property evaluation using a slicing machine or the like.
  • the Young's modulus was measured at room temperature by the resonance method using a 55 x 2 x 10 glass sample.
  • the cracking rate was measured using a 15 x 4 x 4 glass sample, and after the glass sample surface was mirror-finished, using a micro Vickers hardness tester, immediately after applying a load of 500 g for 15 seconds. After a lapse of 20 minutes, the occurrence of cracks from the edge of the pits impression was observed.
  • the cracking rate is one of the evaluation methods to evaluate the impact resistance of a magnetic disk consisting of a glass substrate and a magnetic film when a magnetic head and a magnetic disk device fall.
  • the indentation of Beakers was assumed to be 20 RBIs. Each of the indentations had four wedges, and if cracks were observed from any one of them, the indentation was regarded as cracking.
  • a glass sample with a thermal expansion coefficient of 15x4x4 was used, and the measurement temperature range was 100 to 400 ° C.
  • the amount of alkali elution was measured by a method based on JIS-R3502.
  • the alkali elution test method using JIS-R3502 will be described.
  • the cracking rate from the edge of the indentation at a load of 500 g measured by a Micro Vickers hardness tester was 50% or less, which was significantly reduced as compared with the No. B1 to B5 glasses of the comparative example. This seems to be sufficient for the impact resistance of the magnetic head.
  • the coefficient of thermal expansion was in the range of 62 to 70 ⁇ 10 17 / ° C as in the comparative example, and it was confirmed that the thermal expansion coefficient was sufficiently matched with the stainless steel spacer.
  • the water resistance in JIS-R 3502 was 0.2 mg or less, indicating that the diffusion of alkali metal elements could be prevented.
  • Sn0 2 + Z 1> 0 2 +1 1;? [0 2 + 2110 + ⁇ & 0 + ⁇ 0 + ⁇ 2 0 5 + ⁇ content of 10 is good is 20 molar% or less.
  • No. A20 glass as well, excellent effects could be obtained.
  • a glass containing at least one of oxides of Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu of rare earth elements other than Gd Also obtained an excellent effect. Furthermore, it was found that the same effect was obtained in a glass containing both a Group IIIA element oxide and a rare earth element oxide in the periodic table.
  • G d 2 0 3 wherein the N o of Y 2 03 and a rare earth element oxide of III A group elements oxides of the Periodic Table.
  • Table 4 the glass of No. A22 to No.
  • FIG. 1 is a sectional view of a magnetic disk according to the present invention.
  • a glass substrate 1 On the magnetic disk, a glass substrate 1, a shield film 2, an intermediate film 3, a magnetic film 4, a protective film 5, and a lubricating film 6 are sequentially formed.
  • the surface of the glass substrate 1 of No. A6, No. Al 9s No. A22 described above was prepared by using a sputtering method, and the main component thereof was CoO, which is cobalt oxide.
  • the seed film 2 made of an object film is 15 nm
  • the intermediate film 3 made of a Cr—Ti alloy is 20 nm
  • the magnetic film 4 made of a Co—Cr—Pt alloy is 20 nm
  • the force-bonding protective film 5 is 10 nm was sequentially formed.
  • the film was formed at a glass substrate temperature of 250 to 300 ° C.
  • the sputter ring rate of each membrane was set in the range of 1 to 5 nm / 3 ⁇ 4>.
  • a perfluoropolyether-based lubricant 6 was applied by diving to produce magnetic disks No. AO 61, No. Al 91 and No. A221 in Table 5.
  • No. Bl and No. B2 glasses shown in Table 2 were processed into 2.5-inch magnetic disk substrates. After that, as described above, Magnetic disks No. BO 11 and No. BO 21 were manufactured. Here, a Cr-based metal film was used for the seed film 2 of No. BOil and No. BO21. These magnetic disks were mounted on a 2.5-inch magnetic disk drive. The number of magnetic disks produced was 100 each.
  • FIG. 2 is a schematic diagram of the magnetic disk drive manufactured in this embodiment.
  • the magnetic disk 7 is supported by a rotating shaft 8, and at the same time, the magnetic disk 7 is rotated by rotating a spindle motor 9. 12 is an output terminal of the electric system.
  • the magnetic head 10 is supported by a head rotation shaft 11, and the position of the disk in the radial direction is determined by the rotation of the head rotation shaft 11.
  • three magnetic disks are mounted via the spacer 13, and a total of four magnetic heads are arranged on both surfaces of each disk.
  • a spacer made of stainless steel, which is a metal, has been used.
  • the flying height of the magnetic head was controlled at 2 Onm by adjusting the shape of the magnetic head slider and the spring strength of the arm supporting the magnetic head.
  • the rotation speed of the magnetic disk was 6000 revolutions per minute.
  • No. AO 6 Is No. A191, No. A221, No. B011, No. B021
  • the system was operated for 100 hours, and the presence or absence of errors due to heat generation at the time of a magnetic head collision and deterioration of magnetic properties due to non-orientation of the magnetic film was examined. Furthermore, the magnetic disk was removed from the magnetic disk device, and the surface of the magnetic disk was observed in detail to determine whether there was damage such as film peeling and, if there was any damage, the state of the damage. As a result, all of the magnetic disks No. AO 61 No. A191 and No. A221 using the glass substrate of the present invention have few errors and damages such as scratches on the surface of the magnetic disk, and the magnetic characteristics such as recording / reproducing are low.
  • the magnetic disk Nos. B011 and B021 of the comparative example showed many errors in the high-speed rotation test, and the magnetic characteristic yield of the magnetic disk No. B011 and No. B021 of the comparative example such as recording / reproducing was 56%. It was below. Next, using each of the prepared 20 magnetic disks, a pair of magnetic disks was used.
  • the magnetic disk drive equipped with the magnetic disk using the glass substrate of the present invention can sufficiently increase the capacity of 6000 rotations per minute, thereby increasing the capacity.
  • a 2.5-inch size glass substrate, a magnetic disk, and a device therefor have been described using the embodiment, but the present invention is also applicable to 1-inch, 3-inch, 3.5-inch or other sizes. It is a technology that can be done.
  • This embodiment is an example of an optical disk using a glass composition and an apparatus therefor, as in the second embodiment.
  • the optical disc has a reflective film, a recording film, and a protective film sequentially provided on both sides of a glass substrate, and is further coated with a lubricant.
  • a glass substrate with a diameter of 120 mm and a thickness of 12 mm is used as the glass substrate.
  • a recording film (This C o-S i based oxide thin film, of 1 onm in Si_ ⁇ 2 thin film and lubricant 50nm the protective film
  • a housing of the information recording / reproducing apparatus on which the optical disk is mounted is provided with a spindle motor for rotating the optical disk and an actuator VCM coil for positioning the optical head.
  • the light head is embedded with a calcium titanate-based slider, and is attached to the tip of the actuator. I attached.
  • recording and reproduction on an optical disk are performed using an optical head that generates near-field light.
  • the near-field light is a laser beam having a wavelength of about 1Z10 that leaks out of the focal plane when a laser beam is irradiated onto the spherical surface of a hemispherical lens and the beam is focused.
  • a hemispherical lens was used as the light head, and a laser beam with a wavelength of 41 Onm was irradiated on the hemispherical lens to obtain near-field light with a diameter of 125 nm.
  • the flying distance of the optical head was set to 5 Onm from the surface of the optical disc, and the near-field light was applied to the optical disc to look at the recording film.
  • an optical head that rotates at high speed and generates near-field light is used for recording and reproduction on an optical disk, information can be recorded at a higher density and reproduction can be performed with higher accuracy.
  • a glass substrate characterized by having a Young's modulus of 90 to 90%; a crack occurrence rate from an indentation edge portion at the time of measuring a force of hardness under a load of 30 GPa and 50 Og of 0 to 50%.

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Abstract

La présente invention concerne une composition de verre qui présente un module de Young compris entre 90 et 130 Gpa, et qui, lors d'un essai de dureté Vickers sous une charge de 500g, présente des fissurations sur le bord d'une saillie, dans une proportion de 50 % maximum. Par ailleurs, cette invention concerne une composition de verre caractérisée en ce qu'elle comprend un oxyde, en pourcentage molaire, du silicium entre 40 et 80 % en terme de SiO2, de l'aluminium entre 5 et 30 % en terme de Al2O3, et en sodium entre 8 et 20 % en terme de Na2O. de plus, l'invention concerne un substrat pour support d'enregistrement/reproduction, un disque magnétique, un dispositif d'enregistrement/reproduction et un dispositif à disque magnétique utilisant ladite composition. Cette composition de verre qui peut subir de manière satisfaisante une rotation à grande vitesse de 6000 rpm, fait preuve d'une résistance satisfaisante au choc avec une tête magnétique.
PCT/JP2000/004614 2000-07-10 2000-07-10 Composition de verre, substrat pour support d'enregistrement d'informations, disque magnetique, dispositif d'enregistrement/reproduction d'informations et dispositif a disque magnetique utilisant cette composition Ceased WO2002004371A1 (fr)

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PCT/JP2000/004614 WO2002004371A1 (fr) 2000-07-10 2000-07-10 Composition de verre, substrat pour support d'enregistrement d'informations, disque magnetique, dispositif d'enregistrement/reproduction d'informations et dispositif a disque magnetique utilisant cette composition

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PCT/JP2000/004614 WO2002004371A1 (fr) 2000-07-10 2000-07-10 Composition de verre, substrat pour support d'enregistrement d'informations, disque magnetique, dispositif d'enregistrement/reproduction d'informations et dispositif a disque magnetique utilisant cette composition

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WO2003102927A1 (fr) * 2002-06-03 2003-12-11 Hoya Corporation Substrat en verre pour supports d'enregistrement d'information et support d'enregistrement d'information
JP2006290704A (ja) * 2005-04-14 2006-10-26 Hitachi Ltd ガラス
JP2006327935A (ja) * 2006-08-25 2006-12-07 Konica Minolta Opto Inc ガラス基板
JP2010184862A (ja) * 2010-03-23 2010-08-26 Konica Minolta Opto Inc ガラス基板
US20140141226A1 (en) * 2012-11-21 2014-05-22 Corning Incorporated Ion exchangeable glasses having high hardness and high modulus
JP2016155750A (ja) * 2006-06-08 2016-09-01 Hoya株式会社 情報記録媒体用基板に供するためのガラス、情報記録媒体用基板および情報記録媒体とそれらの製造方法
JP2019519452A (ja) * 2016-05-06 2019-07-11 コーニング インコーポレイテッド イオン交換後の熱処理後に高い圧縮応力を維持するガラス組成物
CN113474308A (zh) * 2019-02-25 2021-10-01 日本板硝子株式会社 玻璃组合物、玻璃板及其制造方法、以及信息记录介质用基板
US20220048809A1 (en) * 2019-06-03 2022-02-17 AGC Inc. Glass, chemically tempered glass, and method for producing same
WO2025206374A1 (fr) * 2024-03-29 2025-10-02 Hoya株式会社 Dispositif d'enregistrement magnétique et structure stratifiée

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JPH0714143A (ja) * 1993-06-28 1995-01-17 Hitachi Ltd 磁気記録媒体及びその製造方法
JPH09249431A (ja) * 1997-03-10 1997-09-22 Hoya Corp 記録媒体用ガラス基板及び記録媒体並びにそれらの製造方法
JPH10231134A (ja) * 1997-02-24 1998-09-02 Nagaoka Sangyo:Kk 切断具
JPH1111974A (ja) * 1997-06-20 1999-01-19 Nippon Sheet Glass Co Ltd 磁気記録媒体用ガラス基板
JPH1160205A (ja) * 1997-08-04 1999-03-02 Yaskawa Electric Corp オゾン発生装置

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JPH10231134A (ja) * 1997-02-24 1998-09-02 Nagaoka Sangyo:Kk 切断具
JPH09249431A (ja) * 1997-03-10 1997-09-22 Hoya Corp 記録媒体用ガラス基板及び記録媒体並びにそれらの製造方法
JPH1111974A (ja) * 1997-06-20 1999-01-19 Nippon Sheet Glass Co Ltd 磁気記録媒体用ガラス基板
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JP4619115B2 (ja) * 2002-06-03 2011-01-26 Ｈｏｙａ株式会社 情報記録媒体用ガラス基板および情報記録媒体
JPWO2003102927A1 (ja) * 2002-06-03 2005-09-29 Hoya株式会社 情報記録媒体用ガラス基板および情報記録媒体
WO2003102927A1 (fr) * 2002-06-03 2003-12-11 Hoya Corporation Substrat en verre pour supports d'enregistrement d'information et support d'enregistrement d'information
JP2006290704A (ja) * 2005-04-14 2006-10-26 Hitachi Ltd ガラス
JP2016155750A (ja) * 2006-06-08 2016-09-01 Hoya株式会社 情報記録媒体用基板に供するためのガラス、情報記録媒体用基板および情報記録媒体とそれらの製造方法
JP2006327935A (ja) * 2006-08-25 2006-12-07 Konica Minolta Opto Inc ガラス基板
JP2010184862A (ja) * 2010-03-23 2010-08-26 Konica Minolta Opto Inc ガラス基板
KR102256457B1 (ko) * 2012-11-21 2021-05-27 코닝 인코포레이티드 고 경도 및 고 탄성률을 갖는 이온 교환가능한 유리
KR20150126816A (ko) * 2012-11-21 2015-11-13 코닝 인코포레이티드 고 경도 및 고 탄성률을 갖는 이온 교환가능한 유리
JP2015535521A (ja) * 2012-11-21 2015-12-14 コーニング インコーポレイテッド 高硬度および高弾性率を有するイオン交換可能ガラス
CN104936911A (zh) * 2012-11-21 2015-09-23 康宁股份有限公司 具有高硬度和高模量的可离子交换玻璃
US10501364B2 (en) 2012-11-21 2019-12-10 Corning Incorporated Ion exchangeable glasses having high hardness and high modulus
US20140141226A1 (en) * 2012-11-21 2014-05-22 Corning Incorporated Ion exchangeable glasses having high hardness and high modulus
JP2019519452A (ja) * 2016-05-06 2019-07-11 コーニング インコーポレイテッド イオン交換後の熱処理後に高い圧縮応力を維持するガラス組成物
CN113474308A (zh) * 2019-02-25 2021-10-01 日本板硝子株式会社 玻璃组合物、玻璃板及其制造方法、以及信息记录介质用基板
US20220139424A1 (en) * 2019-02-25 2022-05-05 Nippon Sheet Glass Company, Limited Glass composition, glass sheet and method for producing same, and substrate for information recording medium
EP3932881A4 (fr) * 2019-02-25 2022-11-23 Nippon Sheet Glass Company, Limited Composition de verre, plaque de verre et son procédé de production et substrat pour support d'enregistrement d'informations
CN113474308B (zh) * 2019-02-25 2023-08-22 日本板硝子株式会社 玻璃组合物、玻璃板及其制造方法、以及信息记录介质用基板
US12573425B2 (en) * 2019-02-25 2026-03-10 Nippon Sheet Glass Company, Limited Glass composition, glass sheet and method for producing same, and substrate for information recording medium
US20220048809A1 (en) * 2019-06-03 2022-02-17 AGC Inc. Glass, chemically tempered glass, and method for producing same
US12415745B2 (en) * 2019-06-03 2025-09-16 AGC Inc. Glass, chemically tempered glass, and method for producing same
WO2025206374A1 (fr) * 2024-03-29 2025-10-02 Hoya株式会社 Dispositif d'enregistrement magnétique et structure stratifiée

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