WO2009093484A1 - Method of manufacturing glass substrate for information recording medium, glass substrate for information recording medium, and magnetic recording medium - Google Patents

Method of manufacturing glass substrate for information recording medium, glass substrate for information recording medium, and magnetic recording medium Download PDF

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Publication number
WO2009093484A1
WO2009093484A1 PCT/JP2009/050116 JP2009050116W WO2009093484A1 WO 2009093484 A1 WO2009093484 A1 WO 2009093484A1 JP 2009050116 W JP2009050116 W JP 2009050116W WO 2009093484 A1 WO2009093484 A1 WO 2009093484A1
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WO
WIPO (PCT)
Prior art keywords
glass substrate
scrub
cleaning
recording medium
information recording
Prior art date
Application number
PCT/JP2009/050116
Other languages
French (fr)
Japanese (ja)
Inventor
Shinichi Saeki
Koji Kato
Futoshi Ishida
Original Assignee
Konica Minolta Opto, Inc.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Konica Minolta Opto, Inc. filed Critical Konica Minolta Opto, Inc.
Publication of WO2009093484A1 publication Critical patent/WO2009093484A1/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
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B1/00—Cleaning by methods involving the use of tools
    • B08B1/30—Cleaning by methods involving the use of tools by movement of cleaning members over a surface
    • B08B1/32—Cleaning by methods involving the use of tools by movement of cleaning members over a surface using rotary cleaning members
    • 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
    • C03C23/00—Other surface treatment of glass not in the form of fibres or filaments
    • C03C23/0075—Cleaning of glass
    • 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
    • G11B5/74—Record carriers characterised by the form, e.g. sheet shaped to wrap around a drum
    • G11B5/82—Disk carriers

Definitions

  • the present invention relates to a method for producing a glass substrate for information recording medium, a glass substrate for information recording medium, and a magnetic recording medium.
  • an aluminum alloy is generally used for a stationary type such as a desktop computer or a server
  • a glass substrate is generally used for a portable type such as a notebook computer or a mobile computer.
  • a portable type such as a notebook computer or a mobile computer.
  • the head mechanically contacts the magnetic disk, there is a problem that the magnetic film is easily peeled off from the substrate. Therefore, glass substrates with little deformation, good smoothness, and high mechanical strength are expected to be widely used not only for portable devices but also for stationary devices and other household information devices in the future. ing.
  • the recording capacity of the magnetic disk can be increased as the distance between the magnetic head and the surface of the magnetic disk is decreased.
  • the distance between the magnetic head and the surface of the magnetic disk is reduced, if the surface of the glass substrate has abnormal protrusions or foreign matter adheres to it, the magnetic head may collide with the protrusions or foreign objects on the magnetic disk. Arise. Therefore, in order to reduce the distance between the magnetic head and the magnetic disk surface and increase the recording capacity of the magnetic disk, it is necessary to reliably eliminate abnormal protrusions and foreign matter adhesion on the surface of the glass substrate. Therefore, the glass substrate surface was polished with an abrasive such as cerium oxide to ensure the smoothness of the glass substrate.
  • the abrasive may remain firmly attached to the glass substrate surface. Even if the glass substrate surface is cleaned by scrubbing after polishing, the firmly attached polishing It was difficult to completely remove the agent.
  • a magnetic recording layer is formed on the surface of a glass substrate with an abrasive attached, there arises a problem that the magnetic recording characteristics are remarkably deteriorated such that pinholes are generated in the film and the flying characteristics of the head become unstable.
  • Patent Document 1 proposes performing ultrasonic cleaning with a detergent, scrub cleaning, ultrasonic cleaning with pure water and three types of cleaning after the polishing step.
  • Patent Document 2 proposes cleaning the glass substrate by a combination of scrub cleaning and carbon dioxide-dissolved water cleaning. JP 2002-74653 A JP 2003-228824 A
  • Patent Document 1 it is considered that abrasives and the like adhering to the glass substrate can be removed to some extent.
  • this proposed technique since three types of cleaning are performed, there is a risk that the cleaning process becomes complicated and the productivity decreases. is there.
  • the proposed technique of Patent Document 2 also requires the introduction of equipment for maintaining and managing gas solubility, which may complicate the cleaning process and reduce productivity.
  • the present invention has been made in view of such problems, and an object of the present invention is for an information recording medium that reliably removes abrasives and foreign matters adhering to a glass substrate without complicating the cleaning process. It is providing the manufacturing method of a glass substrate, and the glass substrate for information recording media manufactured using this manufacturing method.
  • Another object of the present invention is to provide a magnetic recording medium capable of reducing the distance between the magnetic head and the surface of the magnetic recording medium and increasing the recording capacity.
  • the method for manufacturing a glass substrate for an information recording medium having a scrub cleaning step of cleaning using a scrub member that rotates the surface of the glass substrate
  • cleaning is performed with two types of scrub members having different rotation axis directions with respect to the glass substrate surface
  • the angle between the glass substrate surface and the rotation axis of the scrub member is approximately 0 °
  • the method for producing a glass substrate for an information recording medium is characterized in that the cleaning with the other scrub member is such that the angle between the surface of the glass substrate and the rotation axis of the scrub member is approximately 90 °.
  • a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member of approximately 90 ° is defined as the glass substrate surface. 4.
  • the manufacturing method of the glass substrate for information recording medium has a polishing step of polishing the glass substrate surface, 7.
  • a glass substrate for an information recording medium which is produced by the production method according to any one of 1 to 8 above.
  • a magnetic recording medium comprising a magnetic film on the surface of the glass substrate for information recording medium according to 9 above.
  • the scrub cleaning step performs cleaning with two types of scrub members having different rotation axis directions with respect to the glass substrate surface, and cleaning with one of the scrub members is performed.
  • the angle between the glass substrate surface and the rotation axis of the scrub member is approximately 0 °, and the cleaning with the other scrub member is approximately 90 ° between the glass substrate surface and the rotation axis of the scrub member. Therefore, removal of the abrasive and foreign matter on the surface of the glass substrate is surely performed.
  • the glass substrate is cleaned by the above-described cleaning method, so that the cleaning process is simplified and the productivity can be improved.
  • the magnetic recording layer is formed on the glass substrate manufactured by the above manufacturing method, the distance between the magnetic head and the surface of the magnetic recording medium can be reduced, and the recording capacity can be reduced. Can be bigger.
  • the present invention will be described based on the illustrated embodiment, but the present invention is not limited to the embodiment.
  • the scrub cleaning used in the present invention means a cleaning method in which the scrub member is rotated and pressed against the surface to be cleaned, and the surface is scraped.
  • FIG. 1 shows an overall configuration of an information recording medium glass substrate (hereinafter also referred to as a glass substrate) 1 as an embodiment of the present invention.
  • the glass substrate 1 has a donut-like disk shape with a hole 5 formed in the center.
  • 10t is an outer peripheral end surface
  • 20t is an inner peripheral end surface
  • 7a and 7b are glass substrate surfaces
  • 7a is also called a front main surface
  • 7b is also called a back main surface.
  • FIG. 2 is a diagram showing an example of a magnetic recording medium (hereinafter also referred to as a magnetic disk) D provided with a magnetic film 2 on the front main surface 7a of the glass substrate 1 shown in FIG.
  • the magnetic film 2 can also be provided on the back main surface 7b.
  • FIG. 3 shows a manufacturing process diagram of an embodiment of a method for manufacturing a glass substrate for an information recording medium according to the present invention.
  • the main feature of the method for manufacturing a glass substrate for information recording media according to the present invention is that the scrub cleaning step in the manufacturing step of FIG. 3 is performed by two types of scrub members having different rotation axis directions with respect to the glass substrate surface.
  • the cleaning is performed with one of the scrub members, and the angle between the glass substrate surface (7a, 7b) and the rotation axis of the scrub member is approximately 0 °, and the cleaning with the other scrub member is performed with the glass substrate.
  • the angle between the surface (7a, 7b) and the rotation axis of the scrub member is approximately 90 °.
  • Abbreviation indicates that a range of ⁇ 5 ° is included.
  • FIG. 4 shows a case where the angle between the glass substrate surface (7a, 7b) and the rotating shafts 301, 302 of the scrub members 30a, 30b is approximately 0 °
  • FIG. 5 shows the glass substrate surface (7a, 7b). The case where the angle between the scrub members 31a and 31b and the rotation shafts 311 and 312 is approximately 90 ° is shown.
  • the plane S ⁇ b> 1 is a plane including the main surface 7 a of the glass substrate 1.
  • the plane S2 is a plane that includes the rotation axis 300 of the scrub member 30 and intersects the plane S1 at a right angle.
  • An angle ⁇ formed by a straight line L1 intersecting the plane S1 and the plane S2 and the rotation axis 300 is an angle between the glass substrate surface according to the present invention and the rotation axis of the scrub member.
  • the inventors observed the glass substrate after scrub cleaning, for example, when the scrub member was rubbed and cleaned by setting the angle between the glass substrate surface and the rotation axis of the scrub member to approximately 0 °. As shown in FIG. 7 (an enlarged view of a part of the glass substrate surface), it was found that the foreign material 40 remained along the rubbing direction a of the scrub member. It was considered that if the rubbing direction by the scrub member is one direction, there is a direction in which foreign matter tends to remain due to the unevenness of the surface.
  • a scrub cleaning step cleaning is performed with two types of scrub members having different rotation axis directions with respect to the glass substrate surface, and one of the scrub members is cleaned with the glass substrate surface (7a, 7b) and the scrub member.
  • the angle between the rotation axis of the scrub member and the rotation axis of the scrub member was approximately 90 °.
  • the glass substrate surface after the polishing process is initially scrubbed at approximately 0 ° using two types of scrub members whose rotation axis directions are approximately 0 ° and approximately 90 ° with respect to the glass substrate surface. It was cleaned with a member and then with a scrubbing member of approximately 90 °. As a result, it was found that almost all foreign matters remaining on the glass substrate surface can be removed. It turns out that a glass substrate surface with high cleaning quality can be obtained by doing in this way. In addition, even if the glass substrate surface is cleaned twice with either the scrub member whose rotational axis is approximately 0 ° or approximately 90 ° with respect to the glass substrate surface, the remaining foreign matter on the glass substrate surface is sufficiently cleaned. It was not possible to improve the cleaning quality.
  • the cleaning performed by the scrub cleaning device 30 having a scrub member whose angle with the rotation axes of 30a and 30b is approximately 0 ° may be performed first, or the glass substrate surface (7a and 7b) and the scrub as shown in FIG.
  • the cleaning performed by the scrub cleaning device 31 having a scrub member whose angle with the rotation axis of the member is approximately 90 ° may be performed first, and the order may be either.
  • Figure 8 shows a specific example.
  • a scrubbing member in which the angle between the glass substrate surface (7a, 7b) and the rotation shafts 301, 302 of the scrubbing members 30a, 30b is approximately 0 ° at a position shifted downward from the center of the glass substrate 1;
  • a scrub member in which the glass substrate surface is vertical and the angle between the glass substrate surface and the rotation axis of the scrub member is approximately 90 ° is used, and a scrub member in which the angle between the glass substrate surface and the rotation axis of the scrub member is approximately 0 °. It arrange
  • cleaning is performed with a scrub member while the glass substrate 1 is rotated by a support roller 60 that supports and rotates the glass substrate 1. It is preferable. By doing in this way, since the board
  • the scrub cleaning process of the present invention is performed after the polishing process, but is not limited to the process after the polishing process.
  • Glass melting process First, a glass material is melted as a glass melting step.
  • aluminosilicate glass and borosilicate glass are particularly preferable because they are excellent in impact resistance and vibration resistance.
  • the disc-shaped glass substrate precursor may be produced by cutting a sheet glass formed by, for example, a downdraw method or a float method with a grinding stone, without using press molding.
  • the size of the glass substrate there is no limitation on the size of the glass substrate.
  • there are glass substrates of various sizes such as an outer diameter of 2.5 inches, 1.8 inches, 1 inch, and 0.8 inches.
  • the thickness of the glass substrate is not limited, and there are glass substrates having various thicknesses such as 2 mm, 1 mm, and 0.63 mm.
  • the press-molded glass substrate precursor is pierced at the center in the coring process. In the drilling, a hole is drilled in the center by grinding with a core drill or the like equipped with a diamond grindstone or the like in the cutter part.
  • both surfaces of the glass substrate are polished to preliminarily adjust the overall shape of the glass substrate, that is, the parallelism, flatness and thickness of the glass substrate.
  • the inner / outer diameter precision machining step the inner and outer diameters are precisely machined by grinding the outer peripheral end face and the inner peripheral end face of the glass substrate with a grinding wheel such as a drum-shaped diamond.
  • End polishing process A plurality of glass substrates that have undergone the inner and outer diameter processing steps are stacked and laminated, and in this state, the outer peripheral surface and the inner peripheral surface are polished using an end surface polishing machine.
  • both surfaces of the glass substrate are polished again to finely adjust the parallelism, flatness and thickness of the glass substrate.
  • the double-side polishing machine includes a disk-shaped upper surface plate and a lower surface plate that are arranged vertically so as to be parallel to each other, and rotate in opposite directions.
  • a plurality of diamond pellets for polishing the main surface of the glass substrate are attached to the opposing surfaces of the upper and lower surface plates.
  • Between the upper and lower surface plates there are a plurality of carriers that rotate in combination with an internal gear provided in an annular shape on the outer periphery of the lower surface plate and a sun gear provided around the rotation axis of the lower surface plate.
  • the carrier is provided with a plurality of holes, and a glass substrate is fitted into the holes.
  • the upper and lower surface plates, the internal gear and the sun gear can be operated by separate driving.
  • the polishing operation of the polishing machine is such that the upper and lower surface plates rotate in opposite directions, and the carrier sandwiched between the surface plates through the diamond pellets rotates with the surface plate holding a plurality of glass substrates. Revolves in the same direction as the lower surface plate with respect to the center of rotation.
  • the glass substrate can be polished by supplying a grinding liquid between the upper surface plate and the glass substrate, and the lower surface plate and the glass substrate.
  • the load on the surface plate applied to the glass substrate and the rotation speed of the surface plate are adjusted as appropriate according to the desired polishing state.
  • the load per unit area in the first and second lapping steps is preferably 60 g / cm 2 to 120 g / cm 2 .
  • the rotation speed of the surface plate is preferably about 10 to 30 rpm, and the rotation speed of the upper surface plate is preferably about 30 to 40% slower than the lower surface rotation speed. If the load on the surface plate is increased and the rotation speed of the surface plate is increased, the amount of polishing increases, but if the load is increased too much, the surface roughness will not be good, and if the rotation speed is too high, the flatness will be good. Not. Further, when the load is small and the rotation speed of the surface plate is slow, the polishing amount is small and the production efficiency is lowered.
  • the surface roughness of the main surface of the glass substrate is about 2 ⁇ m to 4 ⁇ m for Rmax and about 0.2 ⁇ m to 0.4 ⁇ m for Ra. Is preferable. By setting it as such a surface state, it can polish efficiently by a 1st polishing process through the following chemical strengthening process process.
  • the surface roughness at the time when the first lapping step is completed is preferably such that Rmax is 4 ⁇ m to 8 ⁇ m and Ra is about 0.4 ⁇ m to 0.8 ⁇ m.
  • a method for polishing the glass substrate a method in which a pad is attached to the polishing surfaces of the upper and lower surface plates and a polishing liquid containing an abrasive is supplied and polished can be used.
  • the abrasive include cerium oxide, zirconium oxide, aluminum oxide, manganese oxide, colloidal silica, and diamond. These are dispersed in water and used as a slurry.
  • the pad is divided into a hard pad and a soft pad, but can be appropriately selected and used as necessary.
  • the hard pad include pads made of hard velor, urethane foam, pitch-containing suede, etc.
  • examples of the soft pad include pads made of suede, velor, etc.
  • the polishing method using a pad and an abrasive can correspond to rough polishing to precision polishing by changing the particle size of the abrasive and the type of pad. Therefore, in the first lapping step and the second lapping step, the abrasive material, abrasive particle size, and pad are appropriately combined so that the above-mentioned surface roughness can be obtained by efficiently removing large undulations, chips, cracks, etc. Can respond.
  • polishing machines used in the first lapping process and the second lapping process have the same configuration, but it is preferable to perform polishing using different polishing machines prepared exclusively for the respective processes. This is because the dedicated diamond pellets are pasted, so that the replacement is a large-scale operation, and complicated operations such as resetting the polishing conditions are required, resulting in a reduction in manufacturing efficiency.
  • Chemical strengthening process Next to the second lapping step, as a chemical strengthening treatment step, the glass substrate is immersed in a chemical strengthening solution to form a chemical strengthening layer on the glass substrate. By forming the chemical strengthening layer, impact resistance, vibration resistance, heat resistance and the like can be improved.
  • alkali metal ions such as lithium ions and sodium ions contained in the glass substrate are converted into alkali metal ions such as potassium ions having a larger ion radius. It is carried out by the ion exchange method of substituting. Compressive stress is generated in the ion-exchanged region due to the distortion caused by the difference in ion radius, and the surface of the glass substrate is strengthened.
  • the chemical strengthening treatment liquid is not particularly limited, and a known chemical strengthening treatment liquid can be used.
  • a molten salt containing potassium ions or a molten salt containing potassium ions and sodium ions is generally used.
  • the molten salt containing potassium ions and sodium ions include potassium and sodium nitrates, carbonates, sulfates, and mixed molten salts thereof.
  • the chemical strengthening solution is heated to a temperature higher than the temperature at which the above components melt.
  • the heating temperature of the chemical strengthening treatment liquid is preferably lower than the glass transition point (Tg) of the glass substrate, more preferably lower than the glass transition point ⁇ 50 ° C.
  • the glass substrate is placed in a preheating tank prior to immersion in the chemical strengthening treatment liquid. You may have the preheating process heated to predetermined temperature.
  • the thickness of the chemically strengthened layer is preferably in the range of about 5 ⁇ m to 15 ⁇ m in view of improving the strength of the glass substrate and shortening the polishing process time.
  • the thickness of the reinforcing layer is within this range, a glass substrate having good impact resistance, which is flatness and mechanical strength, can be obtained.
  • the shape of the outer peripheral edge portions of the front main surface 7a and the back main surface 7b after the chemical strengthening treatment step is almost the same as that before the chemical strengthening treatment step, and the chemical strengthening layer of about 5 ⁇ m to 15 ⁇ m is formed on the entire surface of the glass substrate. It is in a state of being placed almost uniformly. (Polishing process) Next, a polishing process as a polishing process is performed.
  • the surface of the glass substrate is precisely finished, and the outer peripheral edge of the main surface is polished to a predetermined shape.
  • the polishing step may be one step, but two steps are preferable.
  • polishing in the first polishing step, the surface roughness is improved and the shape of the present invention is finally efficiently improved so that the surface roughness finally required in the second polishing step can be efficiently obtained. Polishing can be obtained.
  • the polishing method uses a polishing machine having the same configuration as the polishing machine used in the first and second lapping processes except that a pad and a polishing liquid are used instead of the diamond pellets and the grinding liquid used in the lapping process.
  • the pad is a hard pad having a hardness A of about 80 to 90, and it is preferable to use, for example, urethane foam.
  • the abrasive is preferably used in the form of a slurry by dispersing cerium oxide or the like having a particle size of 0.6 to 2.5 ⁇ m in water.
  • the mixing ratio of water and abrasive is preferably about 1: 9 to 3: 7.
  • the load per unit area on the glass substrate by the surface plate is preferably 90 g / cm 2 to 110 g / cm 2 .
  • the load applied to the glass substrate by the surface plate greatly affects the shape of the outer peripheral edge. When the load is increased, the inner side of the outer peripheral end portion tends to decrease and increase toward the outer side. Further, when the load is reduced, the outer peripheral end portion tends to become close to a plane and the surface sagging increases. The load can be determined while observing such a tendency.
  • the rotation speed of the surface plate is 25 to 50 rpm, and the rotation speed of the upper surface plate is 30 to 40% slower than the rotation speed of the lower surface plate.
  • the polishing amount is preferably 30 ⁇ m to 40 ⁇ m according to the above polishing conditions. If it is less than 30 ⁇ m, scratches and defects cannot be sufficiently removed. On the other hand, when it exceeds 40 ⁇ m, the surface roughness can be in the range of Rmax from 2 nm to 60 nm and Ra from 2 nm to 4 nm.
  • the second polishing step is a step of polishing the surface of the glass substrate after the first polishing step more precisely.
  • the pad used in the second polishing step is a soft pad having a hardness of about 65 to 80 (Asker-C) softer than the pad used in the first polishing step.
  • urethane foam or suede is preferably used.
  • cerium oxide or the like similar to that in the first polishing step can be used, but it is preferable to use an abrasive having a finer particle size and less variation in order to make the surface of the glass substrate smoother.
  • An abrasive having an average particle diameter of 40 nm to 70 nm is dispersed in water to form a slurry and used as a polishing liquid.
  • the mixing ratio of water and abrasive is preferably about 1: 9 to 3: 7.
  • the load per unit area on the glass substrate by the surface plate is preferably 90 g / cm 2 to 110 g / cm 2 .
  • the load applied to the glass substrate by the surface plate greatly affects the shape of the outer peripheral edge as in the first polishing step, but the shape cannot be changed as efficiently as the first polishing step because the polishing rate is slow.
  • the change in the shape of the outer peripheral end due to the load adjustment is the same as in the first polishing step, and when the load is increased, the inner side of the outer peripheral end tends to decrease and increase outward. Further, when the load is reduced, the outer peripheral end portion tends to become close to a plane and the surface sagging increases. In order to obtain the shape of the outer peripheral end, the load can be determined while observing such a tendency.
  • the rotation speed of the surface plate is preferably 15 rpm to 35 rpm, and the rotation speed of the upper surface plate is preferably 30% to 40% slower than the rotation speed of the lower surface plate.
  • the polishing conditions in the second polishing step are adjusted to obtain the shape of the outer peripheral edge, and the surface roughness is set to the range of Rmax from 2 nm to 6 nm and Ra from 0.2 nm to 0.4 nm. be able to.
  • the polishing amount is preferably 2 to 5 ⁇ m. When the polishing amount is within this range, minute defects such as minute roughness and undulation generated on the surface and minute scratches generated in the process so far can be efficiently removed. (Scrub cleaning process) Next, scrub cleaning is performed after finishing the polishing process, which is a polishing process.
  • FIG. 4 is a schematic diagram showing a scrub cleaning device 30 having a roll-type scrub member whose angle between the glass substrate surface and the rotation axis of the scrub member is approximately 0 °
  • FIG. 5 is a diagram showing the glass substrate surface and the scrub member. It is a schematic diagram which shows the scrub cleaning apparatus 31 which has a cup-type scrub member whose angle with the rotation axis of this is about 90 degrees.
  • the glass substrate surface after the polishing process is cleaned using a scrub cleaning device 30.
  • the scrub members 30a and 30b clean and rub the main surfaces 7a and 7b while rotating at an angle of approximately 0 ° between the rotation shafts 301 and 302 and the main surfaces 7a and 7b of the glass substrate 1.
  • the scrub cleaning device 31 performs cleaning.
  • the main surfaces 7a and 7b are rubbed and cleaned while rotating at an angle of approximately 90 ° between the rotation shafts 311 and 312 of the scrub members 31a and 31b and the main surfaces 7a and 7b of the glass substrate 1.
  • the scrub cleaning apparatus 30 shown in FIG. 4 sandwiches the glass substrate 1 at the nip portion between sponge rollers 30a and 30b as scrub members as a pair of rotating rollers that are in pressure contact with each other, and the cleaning liquid is applied to the glass substrate 1 from the nozzle 30c disposed at the top. 50 (for example, the cleaning liquid 50 is dropped or sprayed in the vicinity of the contact portion between the sponge rollers 30a and 30b and the glass substrate 1) and simultaneously rotates the pair of sponge rollers 30a and 30b in opposite directions.
  • the glass substrate 1 also cleans the entire front and back surfaces of the glass substrate 1 while being rotated by the three support rollers 60 that support and rotate the glass substrate 1.
  • Each of the three support rollers 60 is a support roller whose surface is covered with rubber, and one of the three support rollers 60 has a drive source and rotates the glass substrate 1.
  • the sponge rollers 30a and 30b whose angles between the main surfaces 7a and 7b of the glass substrate 1 and the rotation shafts 301 and 302 of the sponge rollers 30a and 30b are 0 ° are rotated and cleaned.
  • the rotational speeds of the two sponge rollers 30a and 30b may be the same, or different rotational speeds as required.
  • the rotation speed of the sponge roller is generally in the range of 100 to 1000 rpm, more preferably in the range of 300 to 500 rpm.
  • the rotation speed of the glass substrate 1 is generally in the range of 50 to 500 rpm, more preferably in the range of 100 to 300 rpm.
  • the supply rate of the cleaning liquid 50 is generally in the range of 10 to 1000 ml / min, more preferably in the range of 50 to 500 ml / min.
  • the scrub cleaning time is generally in the range of 5 to 150 seconds, more preferably in the range of 10 to 100 seconds. Further, the cleaning liquid 50 may not be supplied, but it is preferable to supply the cleaning liquid 50 because dirt can be removed more.
  • the glass substrate 1 that has been scrubbed with the scrubbing device 30 is then scrubbed with the scrubbing device 31.
  • the scrub cleaning device 31 in FIG. 5 sandwiches the glass substrate 1 with sponge rollers 31a and 31b as scrub members as a pair of rotating rollers that are in pressure contact with each other, and supplies a cleaning liquid 51 to the glass substrate 1 from a nozzle 31c disposed at the upper part.
  • the cleaning liquid 51 is dripped or sprayed in the vicinity of the contact portion between the sponge rollers 31a and 31b and the glass substrate 1), while simultaneously rotating the pair of sponge rollers 31a and 31b in the same direction and simultaneously rotating the glass substrate.
  • each of the three support rollers 60 is a support roller whose surface is covered with rubber, and one of the three support rollers 60 has a drive source and rotates the glass substrate 1.
  • the sponge rollers 31a and 31b whose angles between the main surfaces 7a and 7b of the glass substrate 1 and the rotation shafts 311 and 312 of the sponge rollers 31a and 31b are 90 ° are rotated and cleaned.
  • the rotation speeds of the two sponge rollers 31a and 31b may be the same or different as required.
  • the rotation speed of the sponge roller is generally in the range of 100 to 1000 rpm, more preferably in the range of 300 to 500 rpm.
  • the rotation speed of the glass substrate 1 is generally in the range of 50 to 500 rpm, more preferably in the range of 100 to 300 rpm.
  • the supply rate of the cleaning liquid 50 is generally in the range of 10 to 1000 ml / min, more preferably in the range of 50 to 500 ml / min.
  • the scrub cleaning time is generally in the range of 5 to 150 seconds, more preferably in the range of 10 to 100 seconds. Further, the cleaning liquid 50 may not be supplied, but it is preferable to supply the cleaning liquid 50 because dirt can be removed more.
  • a known brush or pad may be used in addition to a sponge as a material.
  • the sponge rollers 30a, 30b, 31a, 31b are not particularly limited.
  • resin systems such as cellulose sponge, polyvinyl alcohol sponge, urethane foam, ethylene-vinyl acetate copolymer (EVA) sponge, melamine foam, polyethylene foam, etc.
  • EVA ethylene-vinyl acetate copolymer
  • It can be composed of a sponge such as sponge, natural rubber (NR) sponge, chloroprene rubber (CR) sponge, ethylene-propylene rubber (EPDM) sponge, butadiene-acrylonitrile rubber sponge, or the like.
  • the sponge portion is preferably made of a resin-based sponge, that is, made of resin as a main material.
  • the resin is preferably a hydrophilic polymer such as polyurethane, melamine resin, cellulose, or polyvinyl alcohol.
  • adjacent air holes communicate with each other in the sponge portion.
  • more dirt and cleaning liquid can be accommodated in the pores of the multi-porous material constituting the sponge part, and the ability to retain dirt and the like with the sponge part and the ability to carry the cleaning liquid can be improved.
  • the porosity of the sponge part is preferably 20 to 80%, more preferably 30 to 70%. As a result, it is possible to make the sponge portion have desirable properties such as strength and elasticity, and more excellent ability to retain dirt and the like and support capability of the cleaning liquid by the sponge portion.
  • the sponge part preferably has a hardness of 30 to 70 °, more preferably 35 to 55 °. Accordingly, it is possible to make the sponge portion have desirable properties such as strength and elasticity, and more excellent ability to retain dirt and the like by the sponge portion and support capability of the cleaning liquid.
  • the hardness means a value measured according to JIS K7312.
  • the cleaning liquid used in scrub cleaning a commonly used cleaning liquid or pure water can be used, but it is preferable to clean the glass substrate with water added with hydrogen peroxide.
  • the hydrophilicity of the surface of the scrub member is improved, the contact area between the scrub member and the glass substrate is increased, and the abrasive or foreign matter firmly adhered to the glass substrate surface is reliably removed from the glass substrate surface. become.
  • the glass substrate in order to effectively remove the abrasive and foreign matter on the surface of the glass substrate, it is preferable to bring the glass substrate into contact with the same liquid as the above-mentioned cleaning liquid before scrub cleaning.
  • the time of contact There is no particular limitation on the time of contact, but it is preferable to bring the abrasive or foreign matter firmly adhered to the surface of the glass substrate into contact for 10 minutes or more in order to be lifted by some erosion action by the liquid.
  • the longer the contact time of the glass substrate with the liquid the easier the removal of abrasives and foreign substances from the surface of the glass substrate is.
  • the productivity of the glass substrate decreases, so the preferred contact time is in the range of 5 to 30 minutes. It is. From the viewpoint of preventing foreign matter from adhering to the glass substrate surface, it is recommended that the glass substrate is kept in contact with the liquid until immediately before scrub cleaning.
  • the glass substrate surface is brought into contact with the liquid in such a manner that the glass substrate is immersed in a container in which the liquid is stored, the liquid is sprayed on the glass substrate, or the cloth impregnated with the liquid is coated on the glass substrate.
  • a conventionally well-known form such as a form, can be adopted.
  • a mode in which the glass substrate is immersed in the liquid is preferable in that the entire surface of the glass substrate can be reliably and uniformly brought into contact with the liquid.
  • the glass substrate that has been scrubbed is subjected to ultrasonic detergent cleaning and drying treatment.
  • the drying treatment is performed by immersing the glass substrate in IPA (isopropyl alcohol), dissolving the cleaning liquid component in IPA, replacing the coating liquid on the substrate surface with IPA, and then exposing the substrate to IPA vapor. IPA is evaporated to dry the glass substrate. Thereafter, an inspection is performed as necessary.
  • the substrate drying process is not limited to this, and a method generally known as a glass substrate drying method such as spin drying or air knife drying may be used. (Inspection process) After the cleaning process, the glass substrate is visually inspected for scratches, chips, foreign matters and the like. The glass substrate that has passed the inspection is packed and shipped as a glass substrate for an information recording medium.
  • FIG. 2 is a perspective view of a magnetic disk as an example of a magnetic recording medium.
  • a magnetic film 2 is directly formed on the surface of a circular glass substrate 1 for an information recording medium.
  • a method for forming the magnetic film 2 a conventionally known method can be used. For example, a method in which a thermosetting resin in which magnetic particles are dispersed is spin-coated on a substrate, or a method by sputtering or electroless plating is used. A method is mentioned.
  • the film thickness by spin coating is about 0.3 ⁇ m to 1.2 ⁇ m
  • the film thickness by sputtering is about 0.04 ⁇ m to 0.08 ⁇ m
  • the film thickness by electroless plating is 0.05 ⁇ m to 0.1 ⁇ m. From the viewpoint of thinning and densification, film formation by sputtering and electroless plating is preferable.
  • the magnetic material used for the magnetic film is not particularly limited, and a conventionally known material can be used. However, in order to obtain a high coercive force, Ni having a high crystal anisotropy is basically used, and Ni or A Co-based alloy to which Cr is added is suitable. Specific examples include CoPt, CoCr, CoNi, CoNiCr, CoCrTa, CoPtCr, and CoNiPt containing Co as a main component, CoNiCrPt, CoNiCrTa, CoCrPtTa, CoCrPtB, and CoCrPtSiO.
  • the magnetic film may have a multilayer structure (for example, CoPtCr / CrMo / CoPtCr, CoCrPtTa / CrMo / CoCrPtTa) that is divided by a non-magnetic film (for example, Cr, CrMo, CrV, etc.) to reduce noise.
  • a non-magnetic film for example, Cr, CrMo, CrV, etc.
  • ferrite, iron-rare earth, and granular materials having a structure in which magnetic particles such as Fe, Co, FeCo, CoNiPt are dispersed in a nonmagnetic film made of SiO 2 , BN, etc. Also good.
  • the magnetic film may be either an inner surface type or a vertical type recording format.
  • a lubricant may be thinly coated on the surface of the magnetic film in order to improve the sliding of the magnetic head.
  • the lubricant include those obtained by diluting perfluoropolyether (PFPE), which is a liquid lubricant, with a freon-based solvent.
  • an underlayer or a protective layer may be provided.
  • the underlayer in the magnetic disk is selected according to the magnetic film.
  • the material for the underlayer include at least one material selected from nonmagnetic metals such as Cr, Mo, Ta, Ti, W, V, B, Al, and Ni.
  • Cr alone or a Cr alloy is preferable from the viewpoint of improving magnetic characteristics.
  • the underlayer is not limited to a single layer, and may have a multi-layer structure in which the same or different layers are stacked.
  • a multilayer underlayer such as Cr / Cr, Cr / CrMo, Cr / CrV, NiAl / Cr, NiAl / CrMo, or NiAl / CrV may be used.
  • Examples of the protective layer that prevents wear and corrosion of the magnetic film include a Cr layer, a Cr alloy layer, a carbon layer, a hydrogenated carbon layer, a zirconia layer, and a silica layer.
  • These protective layers can be formed continuously with an in-line type sputtering apparatus, such as an underlayer and a magnetic film.
  • these protective layers may be a single layer, or may have a multilayer structure including the same or different layers. Note that another protective layer may be formed on the protective layer or instead of the protective layer.
  • tetraalkoxysilane is diluted with an alcohol-based solvent on a Cr layer, and then colloidal silica fine particles are dispersed and applied, followed by baking to form a silicon dioxide (SiO 2 ) layer. It may be formed.
  • the glass substrate for an information recording medium of the present invention is not limited to a magnetic recording medium, and can be used for a magneto-optical disk or an optical disk.
  • Example 1 (1) Melting and Press Molding Process Aluminosilicate glass having a Tg of 480 ° C. was used as a glass material, and the molten glass was press molded to produce a glass substrate precursor (outer diameter 68 mm, thickness 1.3 mm). (2) Coring process Next, the circular hole (diameter 18mm) was opened in the center part of the glass substrate using the cylindrical diamond grindstone. (3) 1st lapping process Both surfaces of the glass substrate were grind
  • polishing conditions # 1200 mesh was used as diamond pellets, the load per unit area was 100 g / cm 2 , the rotation speed of the upper surface plate was 30 rpm, and the rotation speed of the lower surface plate was 10 rpm.
  • the thickness of the obtained glass substrate was 0.9 mm, and the surface roughness was Rmax of 1.5 ⁇ m and Ra of 1.0 ⁇ m.
  • Inner / Outer Diameter Precision Machining Step Inner / outer diameter processing was performed with a drum-shaped diamond grindstone to obtain an inner diameter of 20 mm and an outer diameter of 65 mm.
  • Nylon fibers having a diameter of 0.2 mm were used for the brush bristles of the polishing machine.
  • the polishing liquid cerium oxide having a particle diameter of 3 ⁇ m was used.
  • Rmax was 0.3 ⁇ m and Ra was 0.03 ⁇ m.
  • Second lapping process Both surfaces of the glass substrate were polished using a polishing machine (manufactured by HAMAI).
  • polishing conditions # 1200 mesh was used as diamond pellets, the load per unit area was 100 g / cm 2 , the rotation speed of the upper surface plate was 30 rpm, and the rotation speed of the lower surface plate was 10 rpm.
  • Rmax was 3 ⁇ m and Ra was 0.3 ⁇ m.
  • Chemical strengthening treatment step was performed by immersing the glass substrate in a chemical strengthening treatment solution.
  • a chemical strengthening treatment liquid a mixed molten salt of potassium nitrate (KNO 3 ) and sodium nitrate (NaNO 3 ) was used.
  • the mixing ratio was 1: 1 by mass ratio.
  • the temperature of the chemical strengthening treatment liquid was 400 ° C. and the immersion time was 40 minutes.
  • polishing Step As a first polishing step of the polishing step, a polishing machine (manufactured by HAMAI) was used, and urethane foam having a hardness A of 80 degrees was used for the pad.
  • abrasive cerium oxide having an average particle diameter of 1.5 ⁇ m was dispersed in water and used as a slurry.
  • the mixing ratio of water and abrasive was 2: 8.
  • the load per unit area was 100 g / cm 2 , the upper platen was rotated at 30 rpm, and the lower platen was rotated at 10 rpm.
  • the polishing amount was 30 ⁇ m.
  • the surface roughness of the obtained glass substrate was 30 nm for Rmax and 3 nm for Ra.
  • a polishing machine manufactured by HAMAI
  • urethane foam having a hardness A of 70 degrees was used for the pad.
  • abrasive cerium oxide having an average particle diameter of 60 nm was dispersed in water and used as a slurry.
  • the mixing ratio of water and abrasive was 2: 8.
  • the load per unit area was 90 g / cm 2
  • the upper surface plate was rotated at 30 rpm
  • the lower surface plate was rotated at 10 rpm.
  • the polishing amount was 3 ⁇ m.
  • the rotation speeds of the rollers 30a, 30b, 31a, and 31b were all 300 rpm.
  • the rotation speed of the glass substrate 1 was 200 rpm.
  • As the cleaning liquid hydrogen peroxide having a hydrogen peroxide concentration of 0.5% by mass was used.
  • the cleaning liquid was supplied by spraying in an amount of 100 ml per minute continuously from 3 seconds before the start of scrub cleaning until the end of scrub cleaning. Thus, 100 glass substrates 1 of Example 1 were produced.
  • Example 2 In the scrub cleaning process in Example 1, the scrub cleaning device 31 having a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member shown in FIG.
  • a second scrub cleaning was performed with the scrub cleaning device 30 having a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member shown in FIG. Others were performed in the same manner as in Example 1, and 100 glass substrates 1 of Example 2 were produced.
  • Example 3 In the scrub cleaning process in Example 1, the scrub member whose angle between the glass substrate surface and the rotation axis of the scrub member shown in FIG. 8 is approximately 0 °, and the angle between the glass substrate surface and the rotation axis of the scrub member is approximately 90 °.
  • Scrub cleaning was performed by a scrub cleaning device 32 having a scrub member. Others were performed in the same manner as in Example 1, and 100 glass substrates 1 of Example 3 were produced.

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Abstract

Provided is a manufacturing method of a glass substrate for an information recording medium which reliably removes a polishing agent or foreign matter stuck to the glass substrate without complicating a washing process. The surface of the glass substrate is washed using two kinds of scrub members having the rotation axes in different directions with respect to the surface of the glass substrate. When washing the surface of the glass substrate using one of the scrub members, the angle formed by the surface of the glass substrate and the rotation axis of the scrub member is generally 0º. When washing the surface of the glass substrate using the other scrub member, the angle formed by the surface of the glass substrate and the rotation axis of the scrub member is generally 90º.

Description

情報記録媒体用ガラス基板の製造方法、情報記録媒体用ガラス基板及び磁気記録媒体Manufacturing method of glass substrate for information recording medium, glass substrate for information recording medium and magnetic recording medium
　本発明は、情報記録媒体用ガラス基板の製造方法、情報記録媒体用ガラス基板及び磁気記録媒体に関する。 The present invention relates to a method for producing a glass substrate for information recording medium, a glass substrate for information recording medium, and a magnetic recording medium.
　従来、磁気ディスク用基板としては、デスクトップ用コンピュータやサーバなどの据え置き型にはアルミニウム合金が、他方ノート型コンピュータやモバイル型コンピュータなどの携帯型にはガラス基板が一般に使用されていたが、アルミニウム合金は変形しやすく、また硬さが不十分であるため研磨後の基板表面の平滑性が十分とは言えなかった。さらに、ヘッドが機械的に磁気ディスクに接触する際、磁性膜が基板から剥離しやすいという問題もあった。そこで、変形が少なく、平滑性が良好で、かつ機械的強度の大きいガラス基板が、携帯型のみならず据え置き型の機器やその他の家庭用情報機器にも今後広く使用されていくものと予測されている。 Conventionally, as a substrate for a magnetic disk, an aluminum alloy is generally used for a stationary type such as a desktop computer or a server, while a glass substrate is generally used for a portable type such as a notebook computer or a mobile computer. Was easily deformed and its hardness was insufficient, so that the substrate surface after polishing was not sufficiently smooth. Further, when the head mechanically contacts the magnetic disk, there is a problem that the magnetic film is easily peeled off from the substrate. Therefore, glass substrates with little deformation, good smoothness, and high mechanical strength are expected to be widely used not only for portable devices but also for stationary devices and other household information devices in the future. ing.
　ところで、磁気ディスクの記録容量は、磁気ヘッドと磁気ディスク表面との距離を小さくするほど大きくできる。しかし、磁気ヘッドと磁気ディスク表面との距離を小さくした場合、ガラス基板の表面に異常突起があったり、異物の付着があったりすると、磁気ヘッドが磁気ディスク上の突起や異物に衝突する不具合が生じる。したがって、磁気ヘッドと磁気ディスク表面との距離を小さくして、磁気ディスクの記録容量を増大させるためには、ガラス基板の表面の異常突起や異物付着を確実になくす必要がある。そこでガラス基板表面を酸化セリウムなどの研磨剤を用いて研磨して、ガラス基板の平滑性を確保していた。 By the way, the recording capacity of the magnetic disk can be increased as the distance between the magnetic head and the surface of the magnetic disk is decreased. However, if the distance between the magnetic head and the surface of the magnetic disk is reduced, if the surface of the glass substrate has abnormal protrusions or foreign matter adheres to it, the magnetic head may collide with the protrusions or foreign objects on the magnetic disk. Arise. Therefore, in order to reduce the distance between the magnetic head and the magnetic disk surface and increase the recording capacity of the magnetic disk, it is necessary to reliably eliminate abnormal protrusions and foreign matter adhesion on the surface of the glass substrate. Therefore, the glass substrate surface was polished with an abrasive such as cerium oxide to ensure the smoothness of the glass substrate.
　しかし研磨剤を用いてガラス基板を研磨すると、ガラス基板表面に研磨剤が強固に付着した状態で残留することがあり、研磨後にスクラブ洗浄によってガラス基板表面を洗浄しても、強固に付着した研磨剤を完全に除去することは困難であった。また研磨剤が付着した状態でガラス基板表面に磁気記録層を形成すると、膜にピンホールが発生したり、ヘッドの浮上特性が不安定になるといった磁気記録特性を著しく低下させるという問題が生じる。 However, when a glass substrate is polished using an abrasive, the abrasive may remain firmly attached to the glass substrate surface. Even if the glass substrate surface is cleaned by scrubbing after polishing, the firmly attached polishing It was difficult to completely remove the agent. In addition, if a magnetic recording layer is formed on the surface of a glass substrate with an abrasive attached, there arises a problem that the magnetic recording characteristics are remarkably deteriorated such that pinholes are generated in the film and the flying characteristics of the head become unstable.
　そこで例えば特許文献１では、研磨工程後に、洗剤による超音波洗浄、スクラブ洗浄、純水による超音波洗浄と３種類の洗浄を行うことが提案されている。また特許文献２では、スクラブ洗浄と炭酸ガス溶解水洗浄の組合せによりガラス基板を洗浄することが提案されている。
特開２００２－７４６５３号公報 特開２００３－２２８８２４号公報 Therefore, for example, Patent Document 1 proposes performing ultrasonic cleaning with a detergent, scrub cleaning, ultrasonic cleaning with pure water and three types of cleaning after the polishing step. Patent Document 2 proposes cleaning the glass substrate by a combination of scrub cleaning and carbon dioxide-dissolved water cleaning.
JP 2002-74653 A JP 2003-228824 A
　しかしながら、特許文献１によれば、ガラス基板に付着した研磨剤等はある程度除去できると考えられるが、この提案技術では３種類もの洗浄を行うため、洗浄工程が複雑化し生産性が低下するおそれがある。また特許文献２の提案技術も同様に、ガス溶解度の維持管理をする設備の導入が必要となり、洗浄工程が複雑化し生産性が低下するおそれがある。 However, according to Patent Document 1, it is considered that abrasives and the like adhering to the glass substrate can be removed to some extent. However, in this proposed technique, since three types of cleaning are performed, there is a risk that the cleaning process becomes complicated and the productivity decreases. is there. Similarly, the proposed technique of Patent Document 2 also requires the introduction of equipment for maintaining and managing gas solubility, which may complicate the cleaning process and reduce productivity.
　本発明はこのような問題に鑑みてなされたものであり、その目的とするところは、洗浄工程を複雑化させることなく、ガラス基板に付着した研磨剤や異物を確実に除去する情報記録媒体用ガラス基板の製造方法及び該製造方法を用いて製造される情報記録媒体用ガラス基板を提供することにある。 The present invention has been made in view of such problems, and an object of the present invention is for an information recording medium that reliably removes abrasives and foreign matters adhering to a glass substrate without complicating the cleaning process. It is providing the manufacturing method of a glass substrate, and the glass substrate for information recording media manufactured using this manufacturing method.
　また本発明の別の目的は、磁気ヘッドと磁気記録媒体表面との距離を小さくすることができ、記録容量を大きくできる磁気記録媒体を提供することにある。 Another object of the present invention is to provide a magnetic recording medium capable of reducing the distance between the magnetic head and the surface of the magnetic recording medium and increasing the recording capacity.
　上記の課題は、以下の構成により解決される。 The above problem is solved by the following configuration.
　１．
ガラス基板表面を回転するスクラブ部材を用いて洗浄するスクラブ洗浄工程を有する情報記録媒体用ガラス基板の製造方法において、
前記スクラブ洗浄工程は、前記ガラス基板表面に対して回転軸の方向の異なる２種類のスクラブ部材で洗浄を行い、
そのうちの一方のスクラブ部材による洗浄は、前記ガラス基板表面と前記スクラブ部材の回転軸との角度が、略０°であり、
もう一方のスクラブ部材による洗浄は、前記ガラス基板表面と前記スクラブ部材の回転軸との角度が、略９０°であることを特徴とする情報記録媒体用ガラス基板の製造方法。 1.
In the method for manufacturing a glass substrate for an information recording medium having a scrub cleaning step of cleaning using a scrub member that rotates the surface of the glass substrate,
In the scrub cleaning step, cleaning is performed with two types of scrub members having different rotation axis directions with respect to the glass substrate surface,
In cleaning with one of the scrub members, the angle between the glass substrate surface and the rotation axis of the scrub member is approximately 0 °,
The method for producing a glass substrate for an information recording medium is characterized in that the cleaning with the other scrub member is such that the angle between the surface of the glass substrate and the rotation axis of the scrub member is approximately 90 °.
　２．
前記回転軸の方向の異なる２種類のスクラブ部材による洗浄は、一方のスクラブ部材による洗浄後に、もう一方のスクラブ部材による洗浄を行うことを特徴とする前記１に記載の情報記録媒体用ガラス基板の製造方法。 2.
2. The glass substrate for an information recording medium according to 1 above, wherein the cleaning with the two types of scrub members having different rotation axis directions is performed by cleaning with the other scrub member after the cleaning with one scrub member. Production method.
　３．
　前記回転軸の方向の異なる２種類のスクラブ部材による洗浄は、一方のスクラブ部材による洗浄と、もう一方のスクラブ部材による洗浄を同時に行うことを特徴とする前記１に記載の情報記録媒体用ガラス基板の製造方法。 3.
2. The glass substrate for an information recording medium according to 1 above, wherein the cleaning with the two types of scrub members having different directions of the rotating shaft is performed simultaneously with cleaning with one scrub member and cleaning with the other scrub member. Manufacturing method.
　４．
前記スクラブ洗浄工程は、前記ガラス基板に洗浄液を供給し、前記スクラブ部材で洗浄を行うことを特徴とする前記１から３の何れか１項に記載の情報記録媒体用ガラス基板の製造方法。 4).
4. The method for manufacturing a glass substrate for an information recording medium according to any one of 1 to 3, wherein the scrub cleaning step supplies a cleaning liquid to the glass substrate and performs cleaning with the scrub member.
　５．
前記ガラス基板表面を垂直にして、前記回転方向の異なる２種類のスクラブ部材のうち、前記ガラス基板表面と前記スクラブ部材の回転軸との角度が略９０°のスクラブ部材を、前記ガラス基板表面と前記スクラブ部材の回転軸との角度が略０°のスクラブ部材よりも、鉛直方向上方に配置することを特徴とする前記３に記載の情報記録媒体用ガラス基板の製造方法。 5).
Of the two types of scrub members having different rotation directions with the glass substrate surface vertical, a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member of approximately 90 ° is defined as the glass substrate surface. 4. The method for producing a glass substrate for an information recording medium according to the item 3, wherein the scrub member is disposed vertically above a scrub member having an angle with a rotation axis of the scrub member of approximately 0 °.
　６．
前記スクラブ洗浄工程は、前記ガラス基板を支持しかつ回転させる支持ローラにより、前記ガラス基板を回転させながら、前記スクラブ部材で洗浄を行うことを特徴とする前記１から５の何れか１項に記載の情報記録媒体用ガラス基板の製造方法。 6).
6. The scrubbing process according to any one of 1 to 5, wherein the scrubbing member performs cleaning with the scrub member while rotating the glass substrate by a support roller that supports and rotates the glass substrate. The manufacturing method of the glass substrate for information recording media of.
　７．
前記情報記録媒体用ガラス基板の製造方法は、前記ガラス基板表面を研磨する研磨工程を有し、
該研磨工程の後に、前記ガラス基板表面をスクラブ洗浄することを特徴とする前記１から６の何れか１項に記載の情報記録媒体用ガラス基板の製造方法。 7).
The manufacturing method of the glass substrate for information recording medium has a polishing step of polishing the glass substrate surface,
7. The method for producing a glass substrate for an information recording medium according to any one of 1 to 6, wherein the surface of the glass substrate is scrubbed after the polishing step.
　８．
前記スクラブ部材が表面にスポンジを有する回転ローラであり、該回転ローラを前記ガラス基板表面に接触させてスクラブ洗浄を行うことを特徴とする前記１から７の何れか１項に記載の情報記録媒体用ガラス基板の製造方法。 8).
8. The information recording medium according to any one of 1 to 7, wherein the scrub member is a rotating roller having a sponge on a surface, and scrub cleaning is performed by bringing the rotating roller into contact with the surface of the glass substrate. Method for manufacturing glass substrate.
　９．
前記１から８の何れか１項に記載の製造方法により製造されたことを特徴とする情報記録媒体用ガラス基板。 9.
9. A glass substrate for an information recording medium, which is produced by the production method according to any one of 1 to 8 above.
　１０．
前記９に記載の情報記録媒体用ガラス基板の表面に磁性膜を有することを特徴とする磁気記録媒体。 10.
10. A magnetic recording medium comprising a magnetic film on the surface of the glass substrate for information recording medium according to 9 above.
　本発明の情報記録媒体用ガラス基板の製造方法では、スクラブ洗浄工程は、ガラス基板表面に対して回転軸の方向の異なる２種類のスクラブ部材で洗浄を行い、そのうちの一方のスクラブ部材による洗浄は、ガラス基板表面と前記スクラブ部材の回転軸との角度が、略０°であり、もう一方のスクラブ部材による洗浄は、ガラス基板表面とスクラブ部材の回転軸との角度が、略９０°であるので、ガラス基板表面の研磨剤や異物の除去が確実に行われるようになる。 In the method for manufacturing a glass substrate for an information recording medium of the present invention, the scrub cleaning step performs cleaning with two types of scrub members having different rotation axis directions with respect to the glass substrate surface, and cleaning with one of the scrub members is performed. The angle between the glass substrate surface and the rotation axis of the scrub member is approximately 0 °, and the cleaning with the other scrub member is approximately 90 ° between the glass substrate surface and the rotation axis of the scrub member. Therefore, removal of the abrasive and foreign matter on the surface of the glass substrate is surely performed.
　また、本発明の情報記録媒体用ガラス基板の製造方法では、上記洗浄方法によってガラス基板を洗浄するので、洗浄工程が簡素化され生産性の向上が図れる。 Further, in the method for manufacturing a glass substrate for information recording medium of the present invention, the glass substrate is cleaned by the above-described cleaning method, so that the cleaning process is simplified and the productivity can be improved.
　さらに本発明の磁気記録媒体では、前記の製造方法によって製造されたガラス基板上に磁気記録層を形成してなるので、磁気ヘッドと磁気記録媒体表面との距離を小さくすることができ記録容量を大きくできる。 Furthermore, in the magnetic recording medium of the present invention, since the magnetic recording layer is formed on the glass substrate manufactured by the above manufacturing method, the distance between the magnetic head and the surface of the magnetic recording medium can be reduced, and the recording capacity can be reduced. Can be bigger.
情報記録媒体用ガラス基板の全体構成を示す図である。It is a figure which shows the whole structure of the glass substrate for information recording media. 情報記録媒体用ガラス基板の表主表面の上に磁性膜を備えている磁気記録媒体の例を示す図である。It is a figure which shows the example of the magnetic recording medium provided with the magnetic film on the front main surface of the glass substrate for information recording media. 情報記録媒体用ガラス基板の製造における工程を説明する製造工程図である。It is a manufacturing process figure explaining the process in manufacture of the glass substrate for information recording media. 本発明に係る第１段階のスクラブ洗浄装置の一例を示す模式図である。It is a schematic diagram which shows an example of the 1st step scrub cleaning apparatus which concerns on this invention. 本発明に係る第２段階のスクラブ洗浄装置の一例を示す模式図である。It is a schematic diagram which shows an example of the scrub cleaning apparatus of the 2nd step which concerns on this invention. 本発明に係るガラス基板表面とスクラブ部材の回転軸との角度について説明するための模式図である。It is a schematic diagram for demonstrating the angle of the glass substrate surface which concerns on this invention, and the rotating shaft of a scrub member. スクラブ洗浄後のガラス基板表面の異物の付着状態を示す拡大図である。It is an enlarged view which shows the adhesion state of the foreign material on the glass substrate surface after scrub cleaning. 本発明に係る回転軸の方向の異なる２種類のスクラブ部材による洗浄を同時に行うスクラブ洗浄装置の一例を示す模式図である。It is a schematic diagram which shows an example of the scrub washing | cleaning apparatus which performs washing | cleaning by two types of scrub members from which the direction of a rotating shaft differs according to this invention simultaneously.
符号の説明Explanation of symbols
　１　情報記録媒体用ガラス基板（ガラス基板）
　２　磁性膜
　５　穴
　７ａ　ガラス基板表面（表主表面）
　７ｂ　ガラス基板表面（裏主表面）
　１０ｔ　外周端面
　２０ｔ　内周端面
　３０、３１、３２　スクラブ洗浄装置
　３０ａ、３０ｂ、３１ａ、３１ｂ　スポンジローラ（スクラブ部材）
　３０ｃ、３１ｃ　ノズル
　５０　洗浄液
　Ｄ　磁気ディスク 1 Glass substrate for information recording media (glass substrate)
2 Magnetic film 5 Hole 7a Glass substrate surface (front main surface)
7b Glass substrate surface (back main surface)
10t outer peripheral end surface 20t inner peripheral end surface 30, 31, 32 Scrub cleaning device 30a, 30b, 31a, 31b Sponge roller (scrub member)
30c, 31c Nozzle 50 Cleaning liquid D Magnetic disk
　本発明を図示の実施の形態に基づいて説明するが、本発明は該実施の形態に限らない。なお、本発明で用いるスクラブ洗浄とは、スクラブ部材を回転させて、被洗浄面に押し当て、表面の汚れをこすり取る洗浄方法を意味する。 The present invention will be described based on the illustrated embodiment, but the present invention is not limited to the embodiment. The scrub cleaning used in the present invention means a cleaning method in which the scrub member is rotated and pressed against the surface to be cleaned, and the surface is scraped.
　図１は、本発明の一実施形態としての情報記録媒体用ガラス基板（以降、ガラス基板とも称する。）１の全体構成を示している。図１に示す様に、ガラス基板１は、中心に穴５が形成されたドーナツ状の円板形状をしている。１０ｔは外周端面、２０ｔは内周端面、７ａ、７ｂはガラス基板表面であり、７ａは表主表面、７ｂは裏主表面とも呼ぶ。また、図２は、図１で示したガラス基板１の表主表面７ａの上に磁性膜２を備えている磁気記録媒体（以降、磁気ディスクとも称する。）Ｄの一例を示す図である。磁性膜２は裏主表面７ｂの上にも設けることができる。 FIG. 1 shows an overall configuration of an information recording medium glass substrate (hereinafter also referred to as a glass substrate) 1 as an embodiment of the present invention. As shown in FIG. 1, the glass substrate 1 has a donut-like disk shape with a hole 5 formed in the center. 10t is an outer peripheral end surface, 20t is an inner peripheral end surface, 7a and 7b are glass substrate surfaces, 7a is also called a front main surface, and 7b is also called a back main surface. FIG. 2 is a diagram showing an example of a magnetic recording medium (hereinafter also referred to as a magnetic disk) D provided with a magnetic film 2 on the front main surface 7a of the glass substrate 1 shown in FIG. The magnetic film 2 can also be provided on the back main surface 7b.
　図３に本発明に係る情報記録媒体用ガラス基板の製造方法の一実施例の製造工程図を示す。 FIG. 3 shows a manufacturing process diagram of an embodiment of a method for manufacturing a glass substrate for an information recording medium according to the present invention.
　本発明に係る情報記録媒体用ガラス基板の製造方法における主な特徴は、図３の製造工程の中のスクラブ洗浄工程が、ガラス基板表面に対して回転軸の方向の異なる２種類のスクラブ部材で洗浄を行い、そのうちの一方のスクラブ部材による洗浄は、ガラス基板表面（７ａ、７ｂ）とスクラブ部材の回転軸との角度が、略０°であり、もう一方のスクラブ部材による洗浄は、ガラス基板表面（７ａ、７ｂ）とスクラブ部材の回転軸との角度が、略９０°であることにある。略とは、±５°の範囲を含むことを示す。 The main feature of the method for manufacturing a glass substrate for information recording media according to the present invention is that the scrub cleaning step in the manufacturing step of FIG. 3 is performed by two types of scrub members having different rotation axis directions with respect to the glass substrate surface. The cleaning is performed with one of the scrub members, and the angle between the glass substrate surface (7a, 7b) and the rotation axis of the scrub member is approximately 0 °, and the cleaning with the other scrub member is performed with the glass substrate. The angle between the surface (7a, 7b) and the rotation axis of the scrub member is approximately 90 °. Abbreviation indicates that a range of ± 5 ° is included.
　ここで本発明で用いているガラス基板表面とスクラブ部材の回転軸との角度について図４、図５、図６を用いて説明する。 Here, the angle between the glass substrate surface used in the present invention and the rotation axis of the scrub member will be described with reference to FIGS. 4, 5, and 6.
　図４は、ガラス基板表面（７ａ、７ｂ）とスクラブ部材３０ａ、３０ｂの回転軸３０１、３０２との角度が、略０°の場合を示し、図５は、ガラス基板表面（７ａ、７ｂ）とスクラブ部材３１ａ、３１ｂの回転軸３１１、３１２との角度が、略９０°の場合を示す。 FIG. 4 shows a case where the angle between the glass substrate surface (7a, 7b) and the rotating shafts 301, 302 of the scrub members 30a, 30b is approximately 0 °, and FIG. 5 shows the glass substrate surface (7a, 7b). The case where the angle between the scrub members 31a and 31b and the rotation shafts 311 and 312 is approximately 90 ° is shown.
　図６において、平面Ｓ１は、ガラス基板１の主表面７ａを含む平面である。平面Ｓ２は、スクラブ部材３０の回転軸３００を含み、平面Ｓ１と直角に交わる平面である。この平面Ｓ１と平面Ｓ２との交差する直線Ｌ１と回転軸３００とのなす角度θを、本発明にかかるガラス基板表面とスクラブ部材の回転軸との角度とする。 In FIG. 6, the plane S <b> 1 is a plane including the main surface 7 a of the glass substrate 1. The plane S2 is a plane that includes the rotation axis 300 of the scrub member 30 and intersects the plane S1 at a right angle. An angle θ formed by a straight line L1 intersecting the plane S1 and the plane S2 and the rotation axis 300 is an angle between the glass substrate surface according to the present invention and the rotation axis of the scrub member.
　従来、ガラス基板表面をスクラブ洗浄した後、取り切れ無かった残存異物を別の洗浄方法で洗浄し、除去していた。しかし、別の洗浄方法を用いると、新たな設備が必要になったり、工程が複雑になったりしていた。そこで、発明人等は、スクラブ洗浄後のガラス基板を観察したところ、例えば、ガラス基板表面とスクラブ部材の回転軸との角度を、略０°にして、スクラブ部材を摺擦させ、洗浄した場合、図７（ガラス基板表面の一部の拡大図である。）に示すようにスクラブ部材の摺擦方向ａに沿って異物４０が残存していることがわかった。これは、スクラブ部材による摺擦方向が一方向であると、表面の凹凸状態により、異物の残りやすい方向があると考えられた。そこで、スクラブ洗浄工程として、ガラス基板表面に対して回転軸の方向の異なる２種類のスクラブ部材による洗浄を行い、そのうちの一方のスクラブ部材による洗浄は、ガラス基板表面（７ａ、７ｂ）とスクラブ部材の回転軸との角度が、略０°であり、もう一方のスクラブ部材による洗浄は、ガラス基板表面（７ａ、７ｂ）とスクラブ部材の回転軸との角度が、略９０°とした。 Conventionally, after scrub cleaning the surface of the glass substrate, the remaining foreign matter that could not be removed was cleaned and removed by another cleaning method. However, when another cleaning method is used, new equipment is required or the process becomes complicated. Therefore, the inventors observed the glass substrate after scrub cleaning, for example, when the scrub member was rubbed and cleaned by setting the angle between the glass substrate surface and the rotation axis of the scrub member to approximately 0 °. As shown in FIG. 7 (an enlarged view of a part of the glass substrate surface), it was found that the foreign material 40 remained along the rubbing direction a of the scrub member. It was considered that if the rubbing direction by the scrub member is one direction, there is a direction in which foreign matter tends to remain due to the unevenness of the surface. Therefore, as a scrub cleaning step, cleaning is performed with two types of scrub members having different rotation axis directions with respect to the glass substrate surface, and one of the scrub members is cleaned with the glass substrate surface (7a, 7b) and the scrub member. The angle between the rotation axis of the scrub member and the rotation axis of the scrub member was approximately 90 °.
　具体的には、研磨工程後のガラス基板表面を、該ガラス基板表面に対して回転軸の方向が略０°と略９０°の２種類のスクラブ部材を用いて、初めに略０°のスクラブ部材で洗浄し、次に略９０°のスクラブ部材で洗浄した。その結果、ガラス基板表面に残存する異物を、ほとんど除去できることがわかった。このようにすることで、洗浄品質の高い、ガラス基板表面を得ることが出来ることがわかる。なお、ガラス基板表面に対して回転軸の方向が略０°又は略９０°のスクラブ部材のどちらか一方でガラス基板表面の洗浄を２回行っても、ガラス基板表面の残存異物を十分に洗浄することはできず、大幅な洗浄品質の向上は得られなかった。なお、ガラス基板表面に対して回転軸の方向が略０°と略９０°の２種類のスクラブ部材を用いて洗浄を行う場合、図４のようにガラス基板表面（７ａ、７ｂ）とスクラブ部材３０ａ、３０ｂの回転軸との角度が、略０°のスクラブ部材を有するスクラブ洗浄装置３０で行う洗浄を先に行っても良いし、図５のようにガラス基板表面（７ａ、７ｂ）とスクラブ部材の回転軸との角度が、略９０°のスクラブ部材を有するスクラブ洗浄装置３１で行う洗浄を先に行っても良く、その順序はどちらでも良い。 Specifically, the glass substrate surface after the polishing process is initially scrubbed at approximately 0 ° using two types of scrub members whose rotation axis directions are approximately 0 ° and approximately 90 ° with respect to the glass substrate surface. It was cleaned with a member and then with a scrubbing member of approximately 90 °. As a result, it was found that almost all foreign matters remaining on the glass substrate surface can be removed. It turns out that a glass substrate surface with high cleaning quality can be obtained by doing in this way. In addition, even if the glass substrate surface is cleaned twice with either the scrub member whose rotational axis is approximately 0 ° or approximately 90 ° with respect to the glass substrate surface, the remaining foreign matter on the glass substrate surface is sufficiently cleaned. It was not possible to improve the cleaning quality. When cleaning is performed using two types of scrub members whose rotation axis directions are approximately 0 ° and approximately 90 ° with respect to the glass substrate surface, the glass substrate surface (7a, 7b) and the scrub member as shown in FIG. The cleaning performed by the scrub cleaning device 30 having a scrub member whose angle with the rotation axes of 30a and 30b is approximately 0 ° may be performed first, or the glass substrate surface (7a and 7b) and the scrub as shown in FIG. The cleaning performed by the scrub cleaning device 31 having a scrub member whose angle with the rotation axis of the member is approximately 90 ° may be performed first, and the order may be either.
　また、ガラス基板表面に対して回転軸の方向が略０°と略９０°の２種類のスクラブ部材で洗浄を行うスクラブ洗浄工程において、略０°のスクラブ部材による洗浄と、略９０°のスクラブ部材による洗浄を同時に行い、ガラス基板１の表面を洗浄するようにしても良い。このようにすることで、１つの洗浄工程の中で、ガラス基板１の表面を一方のスクラブ部材で洗浄した直後に、もう一方のスクラブ部材で洗浄することとなり、前記２回のスクラブ洗浄を行う方法とほぼ同じ効果を得ることができる。 Further, in the scrub cleaning process in which cleaning is performed with two types of scrub members whose rotation axis directions are approximately 0 ° and approximately 90 ° with respect to the glass substrate surface, cleaning with approximately 0 ° scrub members and scrubbing with approximately 90 ° You may make it wash | clean the surface of the glass substrate 1 simultaneously by cleaning with a member. By doing in this way, in one cleaning process, immediately after cleaning the surface of the glass substrate 1 with one scrub member, the other scrub member is cleaned, and the two scrub cleanings are performed. Almost the same effect as the method can be obtained.
　図８に具体例を示す。ガラス基板１の中心より、図の下方にずれた位置で、ガラス基板表面（７ａ、７ｂ）とスクラブ部材３０ａ、３０ｂの回転軸３０１、３０２との角度が、略０°のスクラブ部材と、ガラス基板１の中心より、図の上方で、ガラス基板表面（７ａ、７ｂ）とスクラブ部材３１ａ、３１ｂの回転軸３１１、３１２との角度が、略９０°のスクラブ部材とを有するスクラブ洗浄装置３２でスクラブ洗浄する。ここでは、ガラス基板表面を垂直にして、ガラス基板表面とスクラブ部材の回転軸との角度が略９０°のスクラブ部材を、ガラス基板表面とスクラブ部材の回転軸との角度が略０°のスクラブ部材よりも、鉛直方向上方に配置している。このように配置することにより、よりガラス基板表面の汚れを除去することができ、好ましい。 Figure 8 shows a specific example. A scrubbing member in which the angle between the glass substrate surface (7a, 7b) and the rotation shafts 301, 302 of the scrubbing members 30a, 30b is approximately 0 ° at a position shifted downward from the center of the glass substrate 1; A scrub cleaning device 32 having a scrub member having an angle between the glass substrate surface (7a, 7b) and the rotation shafts 311 and 312 of the scrub members 31a and 31b at approximately 90 ° from the center of the substrate 1 in the upper part of the figure. Scrub clean. Here, a scrub member in which the glass substrate surface is vertical and the angle between the glass substrate surface and the rotation axis of the scrub member is approximately 90 ° is used, and a scrub member in which the angle between the glass substrate surface and the rotation axis of the scrub member is approximately 0 °. It arrange | positions rather than the member in the perpendicular direction. By arranging in this way, dirt on the surface of the glass substrate can be further removed, which is preferable.
　また、ガラス基板１の駆動方法としては、図４、５、８に示すように、ガラス基板１を支持しかつ回転させる支持ローラ６０により、ガラス基板１を回転させながら、スクラブ部材で洗浄を行うことが好ましい。このようにすることで、ガラス基板表面と接触する基板保持部材を用いることがないので、ガラス基板表面を傷つける恐れがなく、また、基板表面全域の汚れを除去でき、好ましい。 As a driving method of the glass substrate 1, as shown in FIGS. 4, 5, and 8, cleaning is performed with a scrub member while the glass substrate 1 is rotated by a support roller 60 that supports and rotates the glass substrate 1. It is preferable. By doing in this way, since the board | substrate holding member which contacts a glass substrate surface is not used, there is no possibility of damaging a glass substrate surface, and the stain | pollution | contamination of the whole substrate surface can be removed, and it is preferable.
　このようにすることにより、ガラス基板１の表面の洗浄品質を高めると共に、より生産性の高い情報記録媒体用ガラス基板の製造方法を提供できる。 By doing so, it is possible to improve the cleaning quality of the surface of the glass substrate 1 and provide a method for producing a glass substrate for an information recording medium with higher productivity.
　情報記録媒体用ガラス基板の製造工程に関して図３の製造工程図を用いて詳しく説明する。なお、図３の製造工程では、本発明のスクラブ洗浄工程を研磨工程の後にしているが、研磨工程後に限定するものではない。
（ガラス溶融工程）
　まず、ガラス溶融工程として、ガラス素材を溶融する。ガラス基板の材料としては、例えば、ＳｉＯ2、Ｎａ2Ｏ、ＣａＯを主成分としたソーダライムガラス；ＳｉＯ2、Ａｌ2Ｏ3、Ｒ2Ｏ（Ｒ＝Ｋ、Ｎａ、Ｌｉ）を主成分としたアルミノシリケートガラス；ボロシリケートガラス；Ｌｉ2Ｏ－ＳｉＯ2系ガラス；Ｌｉ2Ｏ－Ａｌ2Ｏ3－ＳｉＯ2系ガラス；Ｒ’Ｏ－Ａｌ2Ｏ3－ＳｉＯ2系ガラス（Ｒ’＝Ｍｇ、Ｃａ、Ｓｒ、Ｂａ）などを使用することができる。中でも、アルミノシリケートガラスやボロシリケートガラスは、耐衝撃性や耐振動性に優れるため特に好ましい。
（プレス成型工程）
　次に、プレス成形工程として、溶融ガラスを下型に流し込み、上型によってプレス成形して円板状のガラス基板前駆体を得る。なお、円板状のガラス基板前駆体は、プレス成形によらず、例えばダウンドロー法やフロート法で形成したシートガラスを研削砥石で切り出して作製してもよい。 The manufacturing process of the glass substrate for information recording media will be described in detail with reference to the manufacturing process diagram of FIG. In the manufacturing process of FIG. 3, the scrub cleaning process of the present invention is performed after the polishing process, but is not limited to the process after the polishing process.
(Glass melting process)
First, a glass material is melted as a glass melting step. As a material of the glass substrate, for example, soda lime glass mainly composed of SiO 2 , Na 2 O, CaO; mainly composed of SiO 2 , Al 2 O 3 , R 2 O (R = K, Na, Li) Aluminosilicate glass; borosilicate glass; Li 2 O—SiO 2 glass; Li 2 O—Al 2 O 3 —SiO 2 glass; R′O—Al 2 O 3 —SiO 2 glass (R ′ = Mg) , Ca, Sr, Ba) and the like can be used. Among these, aluminosilicate glass and borosilicate glass are particularly preferable because they are excellent in impact resistance and vibration resistance.
(Press molding process)
Next, as a press molding step, molten glass is poured into the lower mold and press molded with the upper mold to obtain a disk-shaped glass substrate precursor. The disc-shaped glass substrate precursor may be produced by cutting a sheet glass formed by, for example, a downdraw method or a float method with a grinding stone, without using press molding.
　ガラス基板の大きさに限定はない。例えば、外径が２．５インチ、１．８インチ、１インチ、０．８インチなど種々の大きさのガラス基板がある。また、ガラス基板の厚みにも限定はなく、２ｍｍ、１ｍｍ、０．６３ｍｍなど種々の厚みのガラス基板がある。
（コアリング加工工程）
　プレス成形したガラス基板前駆体は、コアリング加工工程で、中心部に穴を開ける。穴開けは、カッター部にダイヤモンド砥石等を備えたコアドリル等で研削することで中心部に穴を開ける。
（第１ラッピング工程）
　次に、第１ラッピング工程として、ガラス基板の両表面を研磨加工し、ガラス基板の全体形状、すなわちガラス基板の平行度、平坦度および厚みを予備調整する。
（内・外径精密加工工程）
　次に、内・外径精密加工工程として、ガラス基板の外周端面および内周端面を、例えば鼓状のダイヤモンド等の研削砥石により研削することで内・外径を精密加工する。
（端面研磨加工工程）
　内・外径加工工程を終えたガラス基板を、複数積み重ねて、積層し、その状態で外周面及び内周面の研磨加工を、端面研磨機を用いて研磨する。
（第２ラッピング工程）
　更に、ガラス基板の両表面を再び研磨加工して、ガラス基板の平行度、平坦度および厚みを微調整する。 There is no limitation on the size of the glass substrate. For example, there are glass substrates of various sizes such as an outer diameter of 2.5 inches, 1.8 inches, 1 inch, and 0.8 inches. Further, the thickness of the glass substrate is not limited, and there are glass substrates having various thicknesses such as 2 mm, 1 mm, and 0.63 mm.
(Coring process)
The press-molded glass substrate precursor is pierced at the center in the coring process. In the drilling, a hole is drilled in the center by grinding with a core drill or the like equipped with a diamond grindstone or the like in the cutter part.
(First lapping process)
Next, as a first lapping step, both surfaces of the glass substrate are polished to preliminarily adjust the overall shape of the glass substrate, that is, the parallelism, flatness and thickness of the glass substrate.
(Inner and outer diameter precision machining process)
Next, as the inner / outer diameter precision machining step, the inner and outer diameters are precisely machined by grinding the outer peripheral end face and the inner peripheral end face of the glass substrate with a grinding wheel such as a drum-shaped diamond.
(End polishing process)
A plurality of glass substrates that have undergone the inner and outer diameter processing steps are stacked and laminated, and in this state, the outer peripheral surface and the inner peripheral surface are polished using an end surface polishing machine.
(Second wrapping process)
Further, both surfaces of the glass substrate are polished again to finely adjust the parallelism, flatness and thickness of the glass substrate.
　第１及び第２ラッピング工程にてガラス基板の表裏の表面を研磨する研磨機は、両面研磨機と呼ばれる公知の研磨機を使用できる。両面研磨機は、互いに平行になるように上下に配置された円盤状の上定盤と下定盤とを備えており、互いに逆方向に回転する。この上下の定盤の対向するそれぞれの面にガラス基板の主表面を研磨するための複数のダイヤモンドペレットが貼り付けてある。上下の定盤の間には、下定盤の外周に円環状に設けてあるインターナルギアと下定盤の回転軸の周囲に設けてあるサンギアとに結合して回転する複数のキャリアがある。このキャリアには、複数の穴が設けてあり、この穴にガラス基板をはめ込んで配置する。上下の定盤、インターナルギア及びサンギアは別駆動で動作することができる。 As the polishing machine for polishing the front and back surfaces of the glass substrate in the first and second lapping steps, a known polishing machine called a double-side polishing machine can be used. The double-side polishing machine includes a disk-shaped upper surface plate and a lower surface plate that are arranged vertically so as to be parallel to each other, and rotate in opposite directions. A plurality of diamond pellets for polishing the main surface of the glass substrate are attached to the opposing surfaces of the upper and lower surface plates. Between the upper and lower surface plates, there are a plurality of carriers that rotate in combination with an internal gear provided in an annular shape on the outer periphery of the lower surface plate and a sun gear provided around the rotation axis of the lower surface plate. The carrier is provided with a plurality of holes, and a glass substrate is fitted into the holes. The upper and lower surface plates, the internal gear and the sun gear can be operated by separate driving.
　研磨機の研磨動作は、上下の定盤が互いに逆方向に回転し、ダイヤモンドペレットを介して定盤に挟まれているキャリアは、複数のガラス基板を保持した状態で、自転しながら定盤の回転中心に対して下定盤と同じ方向に公転する。このような動作している研磨機において、研削液を上定盤とガラス基板及び下定盤とガラス基板との間に供給することでガラス基板の研磨を行うことができる。 The polishing operation of the polishing machine is such that the upper and lower surface plates rotate in opposite directions, and the carrier sandwiched between the surface plates through the diamond pellets rotates with the surface plate holding a plurality of glass substrates. Revolves in the same direction as the lower surface plate with respect to the center of rotation. In such an operating polishing machine, the glass substrate can be polished by supplying a grinding liquid between the upper surface plate and the glass substrate, and the lower surface plate and the glass substrate.
　この両面研磨機を使用する際、ガラス基板に加わる定盤の荷重及び定盤の回転数を所望の研磨状態に応じて適宜調整する。第１及び第２ラッピング工程における単位面積当たりの荷重は、６０ｇ／ｃｍ2から１２０ｇ／ｃｍ2とするのが好ましい。また、定盤の回転数は、１０ｒｐｍから３０ｒｐｍ程度とし、上の定盤の回転数を下の定盤回転数より３０％から４０％程度遅くするのが好ましい。定盤による荷重を大きくし、定盤の回転数を速くすると研磨量は多くなるが、荷重を大きくしすぎると面粗さが良好とならず、また、回転数が速すぎると平坦度が良好とならない。また荷重が小さく定盤の回転数が遅いと研磨量が少なく製造効率が低くなる。 When using this double-side polishing machine, the load on the surface plate applied to the glass substrate and the rotation speed of the surface plate are adjusted as appropriate according to the desired polishing state. The load per unit area in the first and second lapping steps is preferably 60 g / cm 2 to 120 g / cm 2 . Further, the rotation speed of the surface plate is preferably about 10 to 30 rpm, and the rotation speed of the upper surface plate is preferably about 30 to 40% slower than the lower surface rotation speed. If the load on the surface plate is increased and the rotation speed of the surface plate is increased, the amount of polishing increases, but if the load is increased too much, the surface roughness will not be good, and if the rotation speed is too high, the flatness will be good. Not. Further, when the load is small and the rotation speed of the surface plate is slow, the polishing amount is small and the production efficiency is lowered.
　第２ラッピング工程を終えた時点で、大きなうねり、欠け、ひび等の欠陥は除去され、ガラス基板の主表面の面粗さは、Ｒｍａｘが２μｍから４μｍ、Ｒａが０．２μｍから０．４μｍ程度とするのが好ましい。このような面状態にしておくことで、次の化学強化処理工程を経て第１ポリッシング工程で研磨を効率よく行うことができる。 When the second lapping process is completed, defects such as large waviness, chipping and cracks are removed, and the surface roughness of the main surface of the glass substrate is about 2 μm to 4 μm for Rmax and about 0.2 μm to 0.4 μm for Ra. Is preferable. By setting it as such a surface state, it can polish efficiently by a 1st polishing process through the following chemical strengthening process process.
　尚、第１ラッピング工程では、第２ラッピング工程を効率よく行うことができるように大まかに大きなうねり、欠け、ひびを効率よく除去する。このため、第２ラッピングで使用する粗さ＃１３００メッシュから＃１７００メッシュより粗い＃８００メッシュから＃１２００メッシュ程度のダイヤモンドペレットを使用するのが好ましい。第１ラッピング工程が完了した時点での面粗さは、Ｒｍａｘが４μｍから８μｍで、Ｒａが０．４μｍから０．８μｍ程度とするのが好ましい。 In the first wrapping step, roughly large undulations, chips and cracks are efficiently removed so that the second wrapping step can be performed efficiently. For this reason, it is preferable to use diamond pellets of # 800 mesh to # 1200 mesh which are coarser than # 1300 mesh to # 1700 mesh used in the second wrapping. The surface roughness at the time when the first lapping step is completed is preferably such that Rmax is 4 μm to 8 μm and Ra is about 0.4 μm to 0.8 μm.
　また、ガラス基板を研磨する方法として、上下の定盤の研磨面にパッドを貼り付け、研磨剤を含む研磨液を供給して研磨する方法を用いることもできる。研磨剤としては、例えば、酸化セリウム、酸化ジルコニウム、酸化アルミニウム、酸化マンガン、コロイダルシリカ、ダイヤモンドなどが挙げられる。これらを水で分散化してスラリー状として使用する。パッドは硬質パッドと軟質パッドとに分けられるが、必要に応じて適宜選択して用いることができる。硬質パッドとしては、硬質ベロア、ウレタン発泡、ピッチ含有スウェード等を素材とするパッドが挙げられ、軟質パッドとしては、スウェードやベロア等を素材とするパッドが挙げられる。 Further, as a method for polishing the glass substrate, a method in which a pad is attached to the polishing surfaces of the upper and lower surface plates and a polishing liquid containing an abrasive is supplied and polished can be used. Examples of the abrasive include cerium oxide, zirconium oxide, aluminum oxide, manganese oxide, colloidal silica, and diamond. These are dispersed in water and used as a slurry. The pad is divided into a hard pad and a soft pad, but can be appropriately selected and used as necessary. Examples of the hard pad include pads made of hard velor, urethane foam, pitch-containing suede, etc., and examples of the soft pad include pads made of suede, velor, etc.
　パッドと研磨剤を使用する研磨方法は、研磨剤の粒度やパッドの種類を変えて、粗研磨から精密研磨まで対応することができる。よって、第１ラッピング工程と第２ラッピング工程で、効率よく大きなうねり、欠け、ひび等を除去し上記の面粗さを得ることができる様に研磨材、研磨材の粒度、パッドを適宜組み合わせて対応することができる。 The polishing method using a pad and an abrasive can correspond to rough polishing to precision polishing by changing the particle size of the abrasive and the type of pad. Therefore, in the first lapping step and the second lapping step, the abrasive material, abrasive particle size, and pad are appropriately combined so that the above-mentioned surface roughness can be obtained by efficiently removing large undulations, chips, cracks, etc. Can respond.
　また、第１及び第２ラッピング工程の後、ガラス基板の表面に残った研磨剤やガラス粉を除去するための洗浄工程を行うことが好ましい。 Further, it is preferable to perform a cleaning process for removing the abrasive and glass powder remaining on the surface of the glass substrate after the first and second lapping processes.
　尚、第１ラッピング工程及び第２ラッピング工程で使用する研磨機は、同一構成ではあるがそれぞれの工程専用に用意された別の研磨機を用いて研磨加工を行うのが好ましい。これは、専用のダイヤモンドペレットを貼り付けているため交換が大掛かりな作業となり、また、研磨条件を再設定する等の煩雑な作業が必要となり、製造効率が低下するためである。
（化学強化処理工程）
　第２ラッピング工程の次に、化学強化処理工程として、化学強化液にガラス基板を浸漬してガラス基板に化学強化層を形成する。化学強化層を形成することで耐衝撃性、耐振動性及び耐熱性等を向上させることができる。 It should be noted that the polishing machines used in the first lapping process and the second lapping process have the same configuration, but it is preferable to perform polishing using different polishing machines prepared exclusively for the respective processes. This is because the dedicated diamond pellets are pasted, so that the replacement is a large-scale operation, and complicated operations such as resetting the polishing conditions are required, resulting in a reduction in manufacturing efficiency.
(Chemical strengthening process)
Next to the second lapping step, as a chemical strengthening treatment step, the glass substrate is immersed in a chemical strengthening solution to form a chemical strengthening layer on the glass substrate. By forming the chemical strengthening layer, impact resistance, vibration resistance, heat resistance and the like can be improved.
　化学強化処理工程は、加熱された化学強化処理液にガラス基板を浸漬することによってガラス基板に含まれるリチウムイオン、ナトリウムイオン等のアルカリ金属イオンをそれよりイオン半径の大きなカリウムイオン等のアルカリ金属イオンによって置換するイオン交換法によって行われる。イオン半径の違いによって生じる歪みより、イオン交換された領域に圧縮応力が発生し、ガラス基板の表面が強化される。 In the chemical strengthening process, by immersing the glass substrate in a heated chemical strengthening solution, alkali metal ions such as lithium ions and sodium ions contained in the glass substrate are converted into alkali metal ions such as potassium ions having a larger ion radius. It is carried out by the ion exchange method of substituting. Compressive stress is generated in the ion-exchanged region due to the distortion caused by the difference in ion radius, and the surface of the glass substrate is strengthened.
　化学強化処理液に特に制限はなく、公知の化学強化処理液を用いることができる。通常、カリウムイオンを含む溶融塩又はカリウムイオンとナトリウムイオンをふくむ溶融塩を用いることが一般的である。カリウムイオンやナトリウムイオンを含む溶融塩としては、カリウムやナトリウムの硝酸塩、炭酸塩、硫酸塩やこれらの混合溶融塩が挙げられる。中でも、融点が低く、ガラス基板の変形を防止できるという観点からは、硝酸塩を用いることが好ましい。 The chemical strengthening treatment liquid is not particularly limited, and a known chemical strengthening treatment liquid can be used. In general, a molten salt containing potassium ions or a molten salt containing potassium ions and sodium ions is generally used. Examples of the molten salt containing potassium ions and sodium ions include potassium and sodium nitrates, carbonates, sulfates, and mixed molten salts thereof. Among these, from the viewpoint that the melting point is low and deformation of the glass substrate can be prevented, it is preferable to use nitrate.
　化学強化処理液は、上記の成分が融解する温度よりも高温になるよう加熱される。一方、化学強化処理液の加熱温度が高すぎると、ガラス基板の温度が上がりすぎ、ガラス基板の変形を招く恐れがある。このため、化学強化処理液の加熱温度はガラス基板のガラス転移点（Ｔｇ）よりも低い温度が好ましく、ガラス転移点－５０℃よりも低い温度とすることが更に好ましい。 The chemical strengthening solution is heated to a temperature higher than the temperature at which the above components melt. On the other hand, when the heating temperature of the chemical strengthening treatment liquid is too high, the temperature of the glass substrate is excessively increased, and the glass substrate may be deformed. For this reason, the heating temperature of the chemical strengthening treatment liquid is preferably lower than the glass transition point (Tg) of the glass substrate, more preferably lower than the glass transition point −50 ° C.
　なお、加熱された化学強化処理液に浸漬される際の熱衝撃によるガラス基板の割れや微細なクラックの発生を防止するため、化学強化処理液への浸漬に先立って、予熱槽でガラス基板を所定温度に加熱する予熱工程を有していても良い。 In addition, in order to prevent the occurrence of cracks and fine cracks in the glass substrate due to thermal shock when immersed in the heated chemical strengthening treatment liquid, the glass substrate is placed in a preheating tank prior to immersion in the chemical strengthening treatment liquid. You may have the preheating process heated to predetermined temperature.
　化学強化層の厚みとしては、ガラス基板の強度向上とポリッシング工程の時間の短縮との兼ね合いから、５μｍ～１５μｍ程度の範囲が好ましい。強化層の厚みがこの範囲の場合、平坦度、機械的強度である耐衝撃性が良好なガラス基板とすることができる。 The thickness of the chemically strengthened layer is preferably in the range of about 5 μm to 15 μm in view of improving the strength of the glass substrate and shortening the polishing process time. When the thickness of the reinforcing layer is within this range, a glass substrate having good impact resistance, which is flatness and mechanical strength, can be obtained.
　化学強化処理工程後の表主表面７ａ及び裏主表面７ｂの外周端部の形状は、化学強化処理工程前とほとんど変わらず、上記の５μｍ～１５μｍ程度の化学強化層がガラス基板の表面全体にほぼ一様に載った状態となる。
（研磨工程）
　次に、研磨工程としてのポリッシング工程を行う。 The shape of the outer peripheral edge portions of the front main surface 7a and the back main surface 7b after the chemical strengthening treatment step is almost the same as that before the chemical strengthening treatment step, and the chemical strengthening layer of about 5 μm to 15 μm is formed on the entire surface of the glass substrate. It is in a state of being placed almost uniformly.
(Polishing process)
Next, a polishing process as a polishing process is performed.
　ポリッシング工程では、ガラス基板の表面を精密に仕上げると伴に主表面の外周端部の形状を所定の形状に研磨する。ポリッシング工程は１工程でも良いが、２工程の方が好ましい。 In the polishing process, the surface of the glass substrate is precisely finished, and the outer peripheral edge of the main surface is polished to a predetermined shape. The polishing step may be one step, but two steps are preferable.
　まず、第１ポリシング工程では、第２ポリッシング工程で最終的に必要とされる面粗さを効率よく得ることができるように、面粗さを向上させるとともに最終的に本発明の形状を効率よく得ることができる研磨を行う。 First, in the first polishing step, the surface roughness is improved and the shape of the present invention is finally efficiently improved so that the surface roughness finally required in the second polishing step can be efficiently obtained. Polishing can be obtained.
　研磨の方法は、ラッピング工程で使用したダイヤモンドペレットと研削液に代えて、パッドと研磨液を使用する以外は第１及び２ラッピング工程で使用した研磨機と同一の構成の研磨機を使用する。 The polishing method uses a polishing machine having the same configuration as the polishing machine used in the first and second lapping processes except that a pad and a polishing liquid are used instead of the diamond pellets and the grinding liquid used in the lapping process.
　パッドは硬度Ａで８０から９０程度の硬質パッドで例えば発泡ウレタンを使用するのが好ましい。パッドの硬度が研磨による発熱により柔らかくなると研磨面の形状変化が大きくなるため硬質パッドを用いるのが好ましい。研磨材は、粒径が０．６μｍから２．５μｍの酸化セリウム等を水に分散させてスラリー状にして用いるのが好ましい。水と研磨剤との混合比率は、概ね１：９から３：７程度が好ましい。 The pad is a hard pad having a hardness A of about 80 to 90, and it is preferable to use, for example, urethane foam. When the pad hardness becomes soft due to heat generated by polishing, the shape change of the polished surface increases, so it is preferable to use a hard pad. The abrasive is preferably used in the form of a slurry by dispersing cerium oxide or the like having a particle size of 0.6 to 2.5 μm in water. The mixing ratio of water and abrasive is preferably about 1: 9 to 3: 7.
　定盤によるガラス基板への単位面積当たりの荷重は、９０ｇ／ｃｍ2から１１０ｇ／ｃｍ2とするのが好ましい。定盤によるガラス基板への荷重は、外周端部の形状に大きく影響する。荷重を大きくしていくと、外周端部の内側が下がり外側に向かって上がる傾向を示す。また、荷重を小さくしていくと、外周端部は平面に近くなるとともに面ダレが大きくなる傾向を示す。こうした傾向を観察しながら荷重を決めることができる。 The load per unit area on the glass substrate by the surface plate is preferably 90 g / cm 2 to 110 g / cm 2 . The load applied to the glass substrate by the surface plate greatly affects the shape of the outer peripheral edge. When the load is increased, the inner side of the outer peripheral end portion tends to decrease and increase toward the outer side. Further, when the load is reduced, the outer peripheral end portion tends to become close to a plane and the surface sagging increases. The load can be determined while observing such a tendency.
　また、面粗さを向上させるために、定盤の回転数を２５ｒｐｍから５０ｒｐｍとし、上の定盤の回転数を下の定盤回転数より３０％から４０％遅くするのが好ましい。 Also, in order to improve the surface roughness, it is preferable that the rotation speed of the surface plate is 25 to 50 rpm, and the rotation speed of the upper surface plate is 30 to 40% slower than the rotation speed of the lower surface plate.
　上記の研磨条件により研磨量を３０μｍから４０μｍとするのが好ましい。３０μｍ未満では、キズや欠陥を十分に除去ができない。また４０μｍを超える場合は、面粗さをＲｍａｘが２ｎｍから６０ｎｍ、Ｒａが２ｎｍから４ｎｍの範囲とすることができるが、必要以上に研磨を行うことになり製造効率が低下する。 The polishing amount is preferably 30 μm to 40 μm according to the above polishing conditions. If it is less than 30 μm, scratches and defects cannot be sufficiently removed. On the other hand, when it exceeds 40 μm, the surface roughness can be in the range of Rmax from 2 nm to 60 nm and Ra from 2 nm to 4 nm.
　第２ポリッシング工程は、第１ポリッシング工程後のガラス基板の表面を更に精密に研磨する工程である。第２ポリッシング工程で使用するパッドは、第１ポリッシング工程で使用するパッドより柔らかい硬度６５から８０（Ａｓｋｅｒ－Ｃ）程度の軟質パッドで、例えば発泡ウレタンやスウェードを使用するのが好ましい。研磨材としては、第１ポリッシング工程と同様の酸化セリウム等を用いることができるが、ガラス基板の表面をより滑らかにするため、粒径がより細かくバラツキが少ない研磨剤を用いるのが好ましい。粒径の平均粒子径が４０ｎｍから７０ｎｍの研磨剤を水に分散させてスラリー状にして研磨液として用い、水と研磨剤との混合比率は、１：９から３：７程度が好ましい。 The second polishing step is a step of polishing the surface of the glass substrate after the first polishing step more precisely. The pad used in the second polishing step is a soft pad having a hardness of about 65 to 80 (Asker-C) softer than the pad used in the first polishing step. For example, urethane foam or suede is preferably used. As the abrasive, cerium oxide or the like similar to that in the first polishing step can be used, but it is preferable to use an abrasive having a finer particle size and less variation in order to make the surface of the glass substrate smoother. An abrasive having an average particle diameter of 40 nm to 70 nm is dispersed in water to form a slurry and used as a polishing liquid. The mixing ratio of water and abrasive is preferably about 1: 9 to 3: 7.
　定盤によるガラス基板への単位面積当たりの荷重は、９０ｇ／ｃｍ2から１１０ｇ／ｃｍ2が好ましい。定盤によるガラス基板への荷重は、第１ポリッシング工程と同様に外周端部の形状に大きく影響するが、研磨速度が遅いため第１ポリッシング工程ほど効率的に形状を変化させることはできない。荷重の加減による外周端部の形状の変化は、第１ポリッシング工程と同様であり、荷重を大きくしていくと、外周端部の内側が下がり外側に向かって上がる傾向を示す。また、荷重を小さくしていくと、外周端部は平面に近くなるとともに面ダレが大きくなる傾向を示す。外周端部の形状を得るために、こうした傾向を観察しながら荷重を決めることができる。定盤の回転数を１５ｒｐｍから３５ｒｐｍとし、上定盤の回転数を下定盤の回転数より３０％から４０％遅くするのが好ましい。 The load per unit area on the glass substrate by the surface plate is preferably 90 g / cm 2 to 110 g / cm 2 . The load applied to the glass substrate by the surface plate greatly affects the shape of the outer peripheral edge as in the first polishing step, but the shape cannot be changed as efficiently as the first polishing step because the polishing rate is slow. The change in the shape of the outer peripheral end due to the load adjustment is the same as in the first polishing step, and when the load is increased, the inner side of the outer peripheral end tends to decrease and increase outward. Further, when the load is reduced, the outer peripheral end portion tends to become close to a plane and the surface sagging increases. In order to obtain the shape of the outer peripheral end, the load can be determined while observing such a tendency. The rotation speed of the surface plate is preferably 15 rpm to 35 rpm, and the rotation speed of the upper surface plate is preferably 30% to 40% slower than the rotation speed of the lower surface plate.
　上記の様に第２ポリッシング工程での研磨条件を調整して外周端部の形状を得ると伴に、面粗さをＲｍａｘが２ｎｍから６ｎｍ、Ｒａが０．２ｎｍから０．４ｎｍの範囲とすることができる。 As described above, the polishing conditions in the second polishing step are adjusted to obtain the shape of the outer peripheral edge, and the surface roughness is set to the range of Rmax from 2 nm to 6 nm and Ra from 0.2 nm to 0.4 nm. be able to.
　研磨量は２μｍから５μｍとするのが好ましい。研磨量をこの範囲とすると、表面に発生した微小な荒れやうねり、これまでの工程で生じた微小な傷痕といった微小な欠陥を効率良く除去することができる。
（スクラブ洗浄工程）
　次に、研磨工程であるポリッシング工程を終えた後にスクラブ洗浄を行う。 The polishing amount is preferably 2 to 5 μm. When the polishing amount is within this range, minute defects such as minute roughness and undulation generated on the surface and minute scratches generated in the process so far can be efficiently removed.
(Scrub cleaning process)
Next, scrub cleaning is performed after finishing the polishing process, which is a polishing process.
　図４と図５を用いて本発明のスクラブ洗浄工程の具体的な例を示す。図４は、ガラス基板表面とスクラブ部材の回転軸との角度が、略０°のロール型のスクラブ部材を有するスクラブ洗浄装置３０を示す模式図であり、図５は、ガラス基板表面とスクラブ部材の回転軸との角度が、略９０°のカップ型のスクラブ部材を有するスクラブ洗浄装置３１を示す模式図である。 A specific example of the scrub cleaning process of the present invention will be described with reference to FIGS. FIG. 4 is a schematic diagram showing a scrub cleaning device 30 having a roll-type scrub member whose angle between the glass substrate surface and the rotation axis of the scrub member is approximately 0 °, and FIG. 5 is a diagram showing the glass substrate surface and the scrub member. It is a schematic diagram which shows the scrub cleaning apparatus 31 which has a cup-type scrub member whose angle with the rotation axis of this is about 90 degrees.
　まず、スクラブ洗浄装置３０を用いて、研磨工程後のガラス基板表面を洗浄する。スクラブ部材３０ａ、３０ｂが、回転軸３０１、３０２とガラス基板１の主表面７ａ、７ｂとの角度が略０°で回転しながら、主表面７ａ、７ｂを摺擦して洗浄する。次に、スクラブ洗浄装置３１で洗浄を行う。スクラブ部材３１ａ、３１ｂの回転軸３１１、３１２とガラス基板１の主表面７ａ、７ｂとの角度が略９０°で回転しながら、主表面７ａ、７ｂを摺擦して洗浄する。 First, the glass substrate surface after the polishing process is cleaned using a scrub cleaning device 30. The scrub members 30a and 30b clean and rub the main surfaces 7a and 7b while rotating at an angle of approximately 0 ° between the rotation shafts 301 and 302 and the main surfaces 7a and 7b of the glass substrate 1. Next, the scrub cleaning device 31 performs cleaning. The main surfaces 7a and 7b are rubbed and cleaned while rotating at an angle of approximately 90 ° between the rotation shafts 311 and 312 of the scrub members 31a and 31b and the main surfaces 7a and 7b of the glass substrate 1.
　スクラブ洗浄装置３０のスクラブ洗浄について説明する。 The scrub cleaning of the scrub cleaning device 30 will be described.
　図４のスクラブ洗浄装置３０は、圧接する一対の回転ローラであるスクラブ部材としてのスポンジローラ３０ａ，３０ｂのニップ部でガラス基板１を挟み込み、上部に配設されたノズル３０ｃからガラス基板１に洗浄液５０を供給（例えば、洗浄液５０は、スポンジローラ３０ａ、３０ｂとガラス基板１との接触部近傍に滴下又はスプレー噴霧）しながら、前記一対のスポンジローラ３０ａ，３０ｂを互いに逆方向に回転させると同時に、ガラス基板１も、ガラス基板１を支持しかつ回転させる３つの支持ローラ６０により、回転させながらガラス基板１の表裏面全体を洗浄するものである。３つの支持ローラ６０は、それぞれ表面をゴムで被覆された支持ローラであり、３つの支持ローラ６０のうち１つが駆動源を持ち、ガラス基板１を回転させている。このようにして、ガラス基板１の主表面７ａ、７ｂとスポンジローラ３０ａ、３０ｂの回転軸３０１、３０２との角度が０°であるスポンジローラ３０ａ、３０ｂを回転させ洗浄している。２つのスポンジローラ３０ａ，３０ｂの回転数はそれぞれ同一でもよいし、必要に応じてそれぞれ異なる回転数としても構わない。スポンジローラの回転数としては一般に１００～１０００ｒｐｍの範囲であり、より好ましくは３００～５００ｒｐｍの範囲である。またガラス基板１の回転数としては一般に５０～５００ｒｐｍの範囲であり、より好ましくは１００～３００ｒｐｍの範囲である。洗浄液５０の供給速度は一般に１０～１０００ｍｌ／分の範囲、より好ましくは５０～５００ｍｌ／分の範囲である。スクラブ洗浄の時間は一般に５～１５０秒の範囲、より好ましくは１０～１００秒の範囲である。また、洗浄液５０の供給は無くてもよいが、供給する方がより汚れを除去でき好ましい。 The scrub cleaning apparatus 30 shown in FIG. 4 sandwiches the glass substrate 1 at the nip portion between sponge rollers 30a and 30b as scrub members as a pair of rotating rollers that are in pressure contact with each other, and the cleaning liquid is applied to the glass substrate 1 from the nozzle 30c disposed at the top. 50 (for example, the cleaning liquid 50 is dropped or sprayed in the vicinity of the contact portion between the sponge rollers 30a and 30b and the glass substrate 1) and simultaneously rotates the pair of sponge rollers 30a and 30b in opposite directions. The glass substrate 1 also cleans the entire front and back surfaces of the glass substrate 1 while being rotated by the three support rollers 60 that support and rotate the glass substrate 1. Each of the three support rollers 60 is a support roller whose surface is covered with rubber, and one of the three support rollers 60 has a drive source and rotates the glass substrate 1. In this manner, the sponge rollers 30a and 30b whose angles between the main surfaces 7a and 7b of the glass substrate 1 and the rotation shafts 301 and 302 of the sponge rollers 30a and 30b are 0 ° are rotated and cleaned. The rotational speeds of the two sponge rollers 30a and 30b may be the same, or different rotational speeds as required. The rotation speed of the sponge roller is generally in the range of 100 to 1000 rpm, more preferably in the range of 300 to 500 rpm. The rotation speed of the glass substrate 1 is generally in the range of 50 to 500 rpm, more preferably in the range of 100 to 300 rpm. The supply rate of the cleaning liquid 50 is generally in the range of 10 to 1000 ml / min, more preferably in the range of 50 to 500 ml / min. The scrub cleaning time is generally in the range of 5 to 150 seconds, more preferably in the range of 10 to 100 seconds. Further, the cleaning liquid 50 may not be supplied, but it is preferable to supply the cleaning liquid 50 because dirt can be removed more.
　スクラブ洗浄装置３０でスクラブ洗浄を行ったガラス基板１を、次にスクラブ洗浄装置３１でスクラブ洗浄を行う。図５のスクラブ洗浄装置３１は、圧接する一対の回転ローラであるスクラブ部材としてのスポンジローラ３１ａ，３１ｂでガラス基板１を挟み込み、上部に配設されたノズル３１ｃからガラス基板１に洗浄液５１を供給（例えば、洗浄液５１は、スポンジローラ３１ａ，３１ｂとガラス基板１との接触部近傍に滴下又はスプレー噴霧）しながら、前記一対のスポンジローラ３１ａ，３１ｂを互いに同方向に回転させると同時に、ガラス基板１も、ガラス基板１を支持しかつ回転させる３つの支持ローラ６０により、スポンジローラ３１ａ、３１ｂと逆の方向に回転させることによりガラス基板１の表裏面全体を洗浄するものである。３つの支持ローラ６０は、それぞれ表面をゴムで被覆された支持ローラであり、３つの支持ローラ６０のうち１つが駆動源を持ち、ガラス基板１を回転させている。このようにして、ガラス基板１の主表面７ａ、７ｂとスポンジローラ３１ａ、３１ｂの回転軸３１１、３１２との角度が９０°であるスポンジローラ３１ａ、３１ｂを回転させ洗浄している。２つのスポンジローラ３１ａ，３１ｂの回転数はそれぞれ同一でもよいし、必要に応じてそれぞれ異なる回転数としても構わない。スポンジローラの回転数としては一般に１００～１０００ｒｐｍの範囲であり、より好ましくは３００～５００ｒｐｍの範囲である。またガラス基板１の回転数としては一般に５０～５００ｒｐｍの範囲であり、より好ましくは１００～３００ｒｐｍの範囲である。洗浄液５０の供給速度は一般に１０～１０００ｍｌ／分の範囲、より好ましくは５０～５００ｍｌ／分の範囲である。スクラブ洗浄の時間は一般に５～１５０秒の範囲、より好ましくは１０～１００秒の範囲である。また、洗浄液５０の供給は無くてもよいが、供給する方がより汚れを除去でき好ましい。 The glass substrate 1 that has been scrubbed with the scrubbing device 30 is then scrubbed with the scrubbing device 31. The scrub cleaning device 31 in FIG. 5 sandwiches the glass substrate 1 with sponge rollers 31a and 31b as scrub members as a pair of rotating rollers that are in pressure contact with each other, and supplies a cleaning liquid 51 to the glass substrate 1 from a nozzle 31c disposed at the upper part. (For example, the cleaning liquid 51 is dripped or sprayed in the vicinity of the contact portion between the sponge rollers 31a and 31b and the glass substrate 1), while simultaneously rotating the pair of sponge rollers 31a and 31b in the same direction and simultaneously rotating the glass substrate. No. 1 also cleans the entire front and back surfaces of the glass substrate 1 by rotating the glass substrate 1 in the direction opposite to the sponge rollers 31a and 31b by the three support rollers 60 that support and rotate the glass substrate 1. Each of the three support rollers 60 is a support roller whose surface is covered with rubber, and one of the three support rollers 60 has a drive source and rotates the glass substrate 1. In this manner, the sponge rollers 31a and 31b whose angles between the main surfaces 7a and 7b of the glass substrate 1 and the rotation shafts 311 and 312 of the sponge rollers 31a and 31b are 90 ° are rotated and cleaned. The rotation speeds of the two sponge rollers 31a and 31b may be the same or different as required. The rotation speed of the sponge roller is generally in the range of 100 to 1000 rpm, more preferably in the range of 300 to 500 rpm. The rotation speed of the glass substrate 1 is generally in the range of 50 to 500 rpm, more preferably in the range of 100 to 300 rpm. The supply rate of the cleaning liquid 50 is generally in the range of 10 to 1000 ml / min, more preferably in the range of 50 to 500 ml / min. The scrub cleaning time is generally in the range of 5 to 150 seconds, more preferably in the range of 10 to 100 seconds. Further, the cleaning liquid 50 may not be supplied, but it is preferable to supply the cleaning liquid 50 because dirt can be removed more.
　スクラブ洗浄装置３０、３１で用いるスクラブ部材としては、図４、図５に示したように、素材としてスポンジの他、従来公知のブラシやパッドなどを用いてももちろん構わない。 As a scrub member used in the scrub cleaning devices 30 and 31, as shown in FIGS. 4 and 5, of course, a known brush or pad may be used in addition to a sponge as a material.
　スポンジローラ３０ａ，３０ｂ、３１ａ，３１ｂとしては、特に限定されず、例えば、セルローススポンジ、ポリビニルアルコールスポンジ、ウレタンフォーム、エチレン－酢酸ビニル共重合体（ＥＶＡ）スポンジ、メラミンフォーム、ポリエチレンフォーム等の樹脂系スポンジ、天然ゴム（ＮＲ）スポンジ、クロロプレンゴム（ＣＲ）スポンジ、エチレン－プロピレンゴム（ＥＰＤＭ）スポンジ、ブタジエン－アクリロニトリルゴムスポンジ等のゴム系スポンジ等で構成することができる。この中でも、スポンジ部分は、樹脂系スポンジで構成、すなわち樹脂を主材料として構成されているのが好ましい。また、前記樹脂は、ポリウレタン、メラミン樹脂、セルロース、ポリビニルアルコール等の親水性ポリマーであるのが好ましい。これにより、スポンジ部分による汚れ等の保持能力および洗浄液の担持能力をより優れたものとすることができ、また、ガラス基板との接触面積も多くなり、より、汚れの除去能力があがる。 The sponge rollers 30a, 30b, 31a, 31b are not particularly limited. For example, resin systems such as cellulose sponge, polyvinyl alcohol sponge, urethane foam, ethylene-vinyl acetate copolymer (EVA) sponge, melamine foam, polyethylene foam, etc. It can be composed of a sponge such as sponge, natural rubber (NR) sponge, chloroprene rubber (CR) sponge, ethylene-propylene rubber (EPDM) sponge, butadiene-acrylonitrile rubber sponge, or the like. Among these, the sponge portion is preferably made of a resin-based sponge, that is, made of resin as a main material. The resin is preferably a hydrophilic polymer such as polyurethane, melamine resin, cellulose, or polyvinyl alcohol. As a result, the ability to retain dirt and the like by the sponge part and the carrying ability of the cleaning liquid can be made more excellent, and the contact area with the glass substrate is increased, thereby further improving the ability to remove dirt.
　また、スポンジ部分は、隣接する空穴同士が連通しているのが好ましい。これにより、スポンジ部分を構成する多穴質体の空穴内により多くの汚れや洗浄液等を収容して、スポンジ部分による汚れ等の保持能力および洗浄液の担持能力をより優れたものとすることができる。 In addition, it is preferable that adjacent air holes communicate with each other in the sponge portion. As a result, more dirt and cleaning liquid can be accommodated in the pores of the multi-porous material constituting the sponge part, and the ability to retain dirt and the like with the sponge part and the ability to carry the cleaning liquid can be improved. .
　スポンジ部分の空穴率が、２０～８０％であるのが好ましく、３０～７０％であるのがより好ましい。これにより、スポンジ部の強度や弾性等の特性を所望のものとしつつ、スポンジ部による汚れ等の保持能力および洗浄液の担持能力をより優れたものとすることができる。 The porosity of the sponge part is preferably 20 to 80%, more preferably 30 to 70%. As a result, it is possible to make the sponge portion have desirable properties such as strength and elasticity, and more excellent ability to retain dirt and the like and support capability of the cleaning liquid by the sponge portion.
　スポンジ部分は、その硬度が３０～７０°であるのが好ましく、３５～５５°であるのがより好ましい。これにより、スポンジ部分の強度や弾性等の特性を所望のものとしつつ、スポンジ部分による汚れ等の保持能力および洗浄液の担持能力をより優れたものとすることができる。なお、ここで、硬度とは、ＪＩＳ　Ｋ７３１２に準拠して測定されたものをいう。 The sponge part preferably has a hardness of 30 to 70 °, more preferably 35 to 55 °. Accordingly, it is possible to make the sponge portion have desirable properties such as strength and elasticity, and more excellent ability to retain dirt and the like by the sponge portion and support capability of the cleaning liquid. Here, the hardness means a value measured according to JIS K7312.
　スクラブ洗浄において用いる洗浄液としては、一般に用いられる洗浄液や純水を用いることが出来るが、過酸化水素を添加した水を用いてガラス基板を洗浄することが好ましい。これにより、スクラブ部材の表面の親水性が向上し、スクラブ部材とガラス基板との接触面積が大きくなり、ガラス基板表面に強固に付着した研磨剤や異物がガラス基板表面から確実に除去されるようになる。 As the cleaning liquid used in scrub cleaning, a commonly used cleaning liquid or pure water can be used, but it is preferable to clean the glass substrate with water added with hydrogen peroxide. As a result, the hydrophilicity of the surface of the scrub member is improved, the contact area between the scrub member and the glass substrate is increased, and the abrasive or foreign matter firmly adhered to the glass substrate surface is reliably removed from the glass substrate surface. become.
　また、ガラス基板表面の研磨剤や異物などを効果的に除去するには、スクラブ洗浄を行う前に前述の洗浄液と同じ液体にガラス基板を接触させておくのが好ましい。接触させておく時間については特に限定はないが、ガラス基板表面に強固に付着した研磨剤や異物を、液体による若干の浸食作用によっては浮き上がらせるためには１０分間以上接触させるのが好ましい。一方、ガラス基板の液体への接触時間が長いほど研磨剤や異物のガラス基板表面からの除去は容易となるが、ガラス基板の生産性が低下するので、好ましい接触時間は５～３０分間の範囲である。またガラス基板表面に異物が付着するのを防止する観点からは、スクラブ洗浄直前までガラス基板を液体と接触させておくことが推奨される。 Also, in order to effectively remove the abrasive and foreign matter on the surface of the glass substrate, it is preferable to bring the glass substrate into contact with the same liquid as the above-mentioned cleaning liquid before scrub cleaning. There is no particular limitation on the time of contact, but it is preferable to bring the abrasive or foreign matter firmly adhered to the surface of the glass substrate into contact for 10 minutes or more in order to be lifted by some erosion action by the liquid. On the other hand, the longer the contact time of the glass substrate with the liquid, the easier the removal of abrasives and foreign substances from the surface of the glass substrate is. However, the productivity of the glass substrate decreases, so the preferred contact time is in the range of 5 to 30 minutes. It is. From the viewpoint of preventing foreign matter from adhering to the glass substrate surface, it is recommended that the glass substrate is kept in contact with the liquid until immediately before scrub cleaning.
　ガラス基板表面を液体と接触させる形態としては、液体を貯溜した容器内にガラス基板を浸漬する形態や、ガラス基板に対して液体を散水する形態、液体を含浸させた布をガラス基板に被覆する形態など従来公知の形態を採用することができる。この中でも、ガラス基板表面全体が確実且つ均一に液体と接触できる点で、ガラス基板を液体に浸漬させる形態が好ましい。 The glass substrate surface is brought into contact with the liquid in such a manner that the glass substrate is immersed in a container in which the liquid is stored, the liquid is sprayed on the glass substrate, or the cloth impregnated with the liquid is coated on the glass substrate. A conventionally well-known form, such as a form, can be adopted. Among these, a mode in which the glass substrate is immersed in the liquid is preferable in that the entire surface of the glass substrate can be reliably and uniformly brought into contact with the liquid.
　このようにして、ガラス基板表面とスクラブ部材の回転軸との角度が、略０°と略９０°の２種類のスクラブ部材による洗浄を行い、ガラス基板表面に付着した研磨剤や異物を確実に除去する。 In this way, cleaning is performed with two types of scrubbing members having an angle between the glass substrate surface and the rotation axis of the scrubbing member of approximately 0 ° and approximately 90 °, so that abrasives and foreign matters adhering to the glass substrate surface can be reliably removed. Remove.
　スクラブ洗浄がなされたガラス基板に対して、必要により超音波による洗剤洗浄および乾燥処理が行われる。乾燥処理は具体的には、ガラス基板をＩＰＡ（イソプロピルアルコール）中に浸漬し、ＩＰＡ中に洗浄液成分を溶け込ませ、基板表面の被覆液体をＩＰＡと置換した後、さらにＩＰＡ蒸気中にさらしながら、ＩＰＡを蒸発させてガラス基板を乾燥させるものである。そしてその後、必要により検査が行われる。基板の乾燥処理としてはこれに限定されるわけではなく、スピン乾燥、エアーナイフ乾燥などガラス基板の乾燥方法として一般的に知られた方法であってももちろん構わない。
（検査工程）
　洗浄工程後に、ガラス基板にキズや欠け、異物等の付着を目視により検査する。検査をパスしたガラス基板は、梱包し、情報記録媒体用ガラス基板として出荷する。 If necessary, the glass substrate that has been scrubbed is subjected to ultrasonic detergent cleaning and drying treatment. Specifically, the drying treatment is performed by immersing the glass substrate in IPA (isopropyl alcohol), dissolving the cleaning liquid component in IPA, replacing the coating liquid on the substrate surface with IPA, and then exposing the substrate to IPA vapor. IPA is evaporated to dry the glass substrate. Thereafter, an inspection is performed as necessary. The substrate drying process is not limited to this, and a method generally known as a glass substrate drying method such as spin drying or air knife drying may be used.
(Inspection process)
After the cleaning process, the glass substrate is visually inspected for scratches, chips, foreign matters and the like. The glass substrate that has passed the inspection is packed and shipped as a glass substrate for an information recording medium.
　次に、上記のようにして作製したガラス基板を用いた磁気記録媒体について説明する。 Next, a magnetic recording medium using the glass substrate produced as described above will be described.
　以下、図面に基づき磁気記録媒体について説明する。 Hereinafter, the magnetic recording medium will be described with reference to the drawings.
　図２は磁気記録媒体の一例である磁気ディスクの斜視図である。この磁気ディスクＤは、円形の情報記録媒体用ガラス基板１の表面に磁性膜２を直接形成されている。磁性膜２の形成方法としては従来公知の方法を用いることができ、例えば磁性粒子を分散させた熱硬化性樹脂を基板上にスピンコートして形成する方法や、スパッタリング、無電解めっきにより形成する方法が挙げられる。スピンコート法での膜厚は約０．３μｍ～１．２μｍ程度、スパッタリング法での膜厚は０．０４μｍ～０．０８μｍ程度、無電解めっき法での膜厚は０．０５μｍ～０．１μｍ程度であり、薄膜化および高密度化の観点からはスパッタリング法および無電解めっき法による膜形成が好ましい。 FIG. 2 is a perspective view of a magnetic disk as an example of a magnetic recording medium. In the magnetic disk D, a magnetic film 2 is directly formed on the surface of a circular glass substrate 1 for an information recording medium. As a method for forming the magnetic film 2, a conventionally known method can be used. For example, a method in which a thermosetting resin in which magnetic particles are dispersed is spin-coated on a substrate, or a method by sputtering or electroless plating is used. A method is mentioned. The film thickness by spin coating is about 0.3 μm to 1.2 μm, the film thickness by sputtering is about 0.04 μm to 0.08 μm, and the film thickness by electroless plating is 0.05 μm to 0.1 μm. From the viewpoint of thinning and densification, film formation by sputtering and electroless plating is preferable.
　磁性膜に用いる磁性材料としては、特に限定はなく従来公知のものが使用できるが、高い保持力を得るために結晶異方性の高いＣｏを基本とし、残留磁束密度を調整する目的でＮｉやＣｒを加えたＣｏ系合金などが好適である。具体的には、Ｃｏを主成分とするＣｏＰｔ、ＣｏＣｒ、ＣｏＮｉ、ＣｏＮｉＣｒ、ＣｏＣｒＴａ、ＣｏＰｔＣｒ、ＣｏＮｉＰｔや、ＣｏＮｉＣｒＰｔ、ＣｏＮｉＣｒＴａ、ＣｏＣｒＰｔＴａ、ＣｏＣｒＰｔＢ、ＣｏＣｒＰｔＳｉＯなどが挙げられる。磁性膜は、非磁性膜（例えば、Ｃｒ、ＣｒＭｏ、ＣｒＶなど）で分割しノイズの低減を図った多層構成（例えば、ＣｏＰｔＣｒ／ＣｒＭｏ／ＣｏＰｔＣｒ、ＣｏＣｒＰｔＴａ／ＣｒＭｏ／ＣｏＣｒＰｔＴａなど）としてもよい。上記の磁性材料の他、フェライト系、鉄－希土類系や、ＳｉＯ2、ＢＮなどからなる非磁性膜中にＦｅ、Ｃｏ、ＦｅＣｏ、ＣｏＮｉＰｔ等の磁性粒子を分散された構造のグラニュラーなどであってもよい。また、磁性膜は、内面型および垂直型のいずれの記録形式であってもよい。 The magnetic material used for the magnetic film is not particularly limited, and a conventionally known material can be used. However, in order to obtain a high coercive force, Ni having a high crystal anisotropy is basically used, and Ni or A Co-based alloy to which Cr is added is suitable. Specific examples include CoPt, CoCr, CoNi, CoNiCr, CoCrTa, CoPtCr, and CoNiPt containing Co as a main component, CoNiCrPt, CoNiCrTa, CoCrPtTa, CoCrPtB, and CoCrPtSiO. The magnetic film may have a multilayer structure (for example, CoPtCr / CrMo / CoPtCr, CoCrPtTa / CrMo / CoCrPtTa) that is divided by a non-magnetic film (for example, Cr, CrMo, CrV, etc.) to reduce noise. In addition to the magnetic materials described above, ferrite, iron-rare earth, and granular materials having a structure in which magnetic particles such as Fe, Co, FeCo, CoNiPt are dispersed in a nonmagnetic film made of SiO 2 , BN, etc. Also good. Further, the magnetic film may be either an inner surface type or a vertical type recording format.
　また、磁気ヘッドの滑りをよくするために磁性膜の表面に潤滑剤を薄くコーティングしてもよい。潤滑剤としては、例えば液体潤滑剤であるパーフロロポリエーテル（ＰＦＰＥ）をフレオン系などの溶媒で希釈したものが挙げられる。 In addition, a lubricant may be thinly coated on the surface of the magnetic film in order to improve the sliding of the magnetic head. Examples of the lubricant include those obtained by diluting perfluoropolyether (PFPE), which is a liquid lubricant, with a freon-based solvent.
　さらに必要により下地層や保護層を設けてもよい。磁気ディスクにおける下地層は磁性膜に応じて選択される。下地層の材料としては、例えば、Ｃｒ、Ｍｏ、Ｔａ、Ｔｉ、Ｗ、Ｖ、Ｂ、Ａｌ、Ｎｉなどの非磁性金属から選ばれる少なくとも一種以上の材料が挙げられる。Ｃｏを主成分とする磁性膜の場合には、磁気特性向上等の観点からＣｒ単体やＣｒ合金であることが好ましい。また、下地層は単層とは限らず、同一又は異種の層を積層した複数層構造としても構わない。例えば、Ｃｒ／Ｃｒ、Ｃｒ／ＣｒＭｏ、Ｃｒ／ＣｒＶ、ＮｉＡｌ／Ｃｒ、ＮｉＡｌ／ＣｒＭｏ、ＮｉＡｌ／ＣｒＶ等の多層下地層としてもよい。 Further, if necessary, an underlayer or a protective layer may be provided. The underlayer in the magnetic disk is selected according to the magnetic film. Examples of the material for the underlayer include at least one material selected from nonmagnetic metals such as Cr, Mo, Ta, Ti, W, V, B, Al, and Ni. In the case of a magnetic film containing Co as a main component, Cr alone or a Cr alloy is preferable from the viewpoint of improving magnetic characteristics. Further, the underlayer is not limited to a single layer, and may have a multi-layer structure in which the same or different layers are stacked. For example, a multilayer underlayer such as Cr / Cr, Cr / CrMo, Cr / CrV, NiAl / Cr, NiAl / CrMo, or NiAl / CrV may be used.
　磁性膜の摩耗や腐食を防止する保護層としては、例えば、Ｃｒ層、Ｃｒ合金層、カーボン層、水素化カーボン層、ジルコニア層、シリカ層などが挙げられる。これらの保護層は、下地層、磁性膜など共にインライン型スパッタ装置で連続して形成できる。また、これらの保護層は、単層としてもよく、あるいは、同一又は異種の層からなる多層構成としてもよい。なお、上記保護層上に、あるいは上記保護層に替えて、他の保護層を形成してもよい。例えば、上記保護層に替えて、Ｃｒ層の上にテトラアルコキシシランをアルコール系の溶媒で希釈した中に、コロイダルシリカ微粒子を分散して塗布し、さらに焼成して二酸化ケイ素（ＳｉＯ2）層を形成してもよい。 Examples of the protective layer that prevents wear and corrosion of the magnetic film include a Cr layer, a Cr alloy layer, a carbon layer, a hydrogenated carbon layer, a zirconia layer, and a silica layer. These protective layers can be formed continuously with an in-line type sputtering apparatus, such as an underlayer and a magnetic film. In addition, these protective layers may be a single layer, or may have a multilayer structure including the same or different layers. Note that another protective layer may be formed on the protective layer or instead of the protective layer. For example, in place of the protective layer, tetraalkoxysilane is diluted with an alcohol-based solvent on a Cr layer, and then colloidal silica fine particles are dispersed and applied, followed by baking to form a silicon dioxide (SiO 2 ) layer. It may be formed.
　上記の様にして得られる本発明の情報記録媒体用ガラス基板を基体とした磁気記録媒体を用いることで、高速回転時の磁気ヘッドの動作を安定にすることができる。 By using a magnetic recording medium based on the glass substrate for information recording medium of the present invention obtained as described above, the operation of the magnetic head during high-speed rotation can be stabilized.
　本発明の情報記録媒体用ガラス基板は、磁気記録媒体に限定されるものではなく、光磁気ディスクや光ディスクなどにも用いることができる。 The glass substrate for an information recording medium of the present invention is not limited to a magnetic recording medium, and can be used for a magneto-optical disk or an optical disk.
（実施例１）
（１）溶融、プレス成型工程
　ガラス材料としてＴｇが４８０℃のアルミノシリケートガラスを用い、溶融ガラスをプレス成形してガラス基板前駆体（外径６８ｍｍ、厚さ１．３ｍｍ）を作製した。
（２）コアリング工程
　次に円筒状のダイヤモンド砥石を用いてガラス基板の中心部に円穴（直径１８ｍｍ）を開けた。
（３）第１ラッピング工程
　ガラス基板の両表面を研磨機（ＨＡＭＡＩ社製）を用いて研磨した。 Example 1
(1) Melting and Press Molding Process Aluminosilicate glass having a Tg of 480 ° C. was used as a glass material, and the molten glass was press molded to produce a glass substrate precursor (outer diameter 68 mm, thickness 1.3 mm).
(2) Coring process Next, the circular hole (diameter 18mm) was opened in the center part of the glass substrate using the cylindrical diamond grindstone.
(3) 1st lapping process Both surfaces of the glass substrate were grind | polished using the grinder (made by HAMAI).
　研磨条件としては、ダイヤモンドペレットとしては、＃１２００メッシュを用い、単位面積当たりの荷重１００ｇ／ｃｍ2とし、上定盤の回転数３０ｒｐｍ、下定盤の回転数１０ｒｐｍとした。 As polishing conditions, # 1200 mesh was used as diamond pellets, the load per unit area was 100 g / cm 2 , the rotation speed of the upper surface plate was 30 rpm, and the rotation speed of the lower surface plate was 10 rpm.
　得られたガラス基板の厚さは、０．９ｍｍ、表面粗さはＲｍａｘが１．５μｍ、Ｒａが１．０μｍであった。
（４）内・外径精密加工工程
　鼓状のダイヤモンド砥石により内・外径加工をい、内径２０ｍｍ、外径６５ｍｍとした。
（５）端面加工工程
　内・外加工工程を終えて得られたガラス基板を１００枚重ね、端面研磨機を用いて、内周及び外周の端面を研磨した。 The thickness of the obtained glass substrate was 0.9 mm, and the surface roughness was Rmax of 1.5 μm and Ra of 1.0 μm.
(4) Inner / Outer Diameter Precision Machining Step Inner / outer diameter processing was performed with a drum-shaped diamond grindstone to obtain an inner diameter of 20 mm and an outer diameter of 65 mm.
(5) End surface processing step 100 glass substrates obtained by finishing the inner and outer processing steps were stacked, and the inner and outer end surfaces were polished using an end surface polishing machine.
　研磨機のブラシ毛は、直径０．２ｍｍのナイロン繊維を用いた。研磨液は、粒径３μｍの酸化セリウムを用いた。得られたガラス基板の内周の端面の面粗さは、Ｒｍａｘが０．３μｍ、Ｒａが０．０３μｍであった。
（６）第２ラッピング工程
　ガラス基板の両表面を研磨機（ＨＡＭＡＩ社製）を用いて研磨した。 Nylon fibers having a diameter of 0.2 mm were used for the brush bristles of the polishing machine. As the polishing liquid, cerium oxide having a particle diameter of 3 μm was used. As for the surface roughness of the inner peripheral end face of the obtained glass substrate, Rmax was 0.3 μm and Ra was 0.03 μm.
(6) Second lapping process Both surfaces of the glass substrate were polished using a polishing machine (manufactured by HAMAI).
　研磨条件としては、ダイヤモンドペレットとしては、＃１２００メッシュを用い、単位面積当たりの荷重１００ｇ／ｃｍ2とし、上定盤の回転数３０ｒｐｍ、下定盤の回転数１０ｒｐｍとした。 As polishing conditions, # 1200 mesh was used as diamond pellets, the load per unit area was 100 g / cm 2 , the rotation speed of the upper surface plate was 30 rpm, and the rotation speed of the lower surface plate was 10 rpm.
　得られたガラス基板の表面粗さはＲｍａｘが３μｍ、Ｒａが０．３μｍであった。
（７）化学強化処理工程
　次に、ガラス基板を化学強化処理液に浸漬して化学強化処理工程を行った。化学強化処理液には、硝酸カリウム（ＫＮＯ3）と硝酸ナトリウム（ＮａＮＯ3）の混合溶融塩を用いた。混合比は質量比で１：１とした。また、化学強化処理液の温度は４００℃、浸漬時間は４０分とした。
（８）研磨工程
　次に研磨工程の第１ポリッシング工程として、研磨機（ＨＡＭＡＩ社製）を用い、パッドに硬度Ａで８０度の発泡ウレタンを用いた。研磨材は、平均粒径１．５μｍの酸化セリウムを水に分散させてスラリー状にして用いた。水と研磨剤との混合比率は、２：８とした。単位面積当たりの荷重１００ｇ／ｃｍ2とし、上定盤の回転数３０ｒｐｍ、下定盤の回転数１０ｒｐｍとした。研磨量を３０μｍとした。 As for the surface roughness of the obtained glass substrate, Rmax was 3 μm and Ra was 0.3 μm.
(7) Chemical strengthening treatment step Next, a chemical strengthening treatment step was performed by immersing the glass substrate in a chemical strengthening treatment solution. As the chemical strengthening treatment liquid, a mixed molten salt of potassium nitrate (KNO 3 ) and sodium nitrate (NaNO 3 ) was used. The mixing ratio was 1: 1 by mass ratio. The temperature of the chemical strengthening treatment liquid was 400 ° C. and the immersion time was 40 minutes.
(8) Polishing Step Next, as a first polishing step of the polishing step, a polishing machine (manufactured by HAMAI) was used, and urethane foam having a hardness A of 80 degrees was used for the pad. As the abrasive, cerium oxide having an average particle diameter of 1.5 μm was dispersed in water and used as a slurry. The mixing ratio of water and abrasive was 2: 8. The load per unit area was 100 g / cm 2 , the upper platen was rotated at 30 rpm, and the lower platen was rotated at 10 rpm. The polishing amount was 30 μm.
　得られたガラス基板の表面粗さはＲｍａｘが３０ｎｍ、Ｒａが３ｎｍであった。 The surface roughness of the obtained glass substrate was 30 nm for Rmax and 3 nm for Ra.
　次に第２ポリッシング工程として、研磨機（ＨＡＭＡＩ社製）を用い、パッドに硬度Ａで７０度の発泡ウレタンを用いた。研磨材は、平均粒径６０ｎｍの酸化セリウムを水に分散させてスラリー状にして用いた。水と研磨剤との混合比率は、２：８とした。単位面積当たりの荷重９０ｇ／ｃｍ2とし、上定盤の回転数３０ｒｐｍ、下定盤の回転数１０ｒｐｍとした。研磨量を３μｍとした。 Next, as a second polishing process, a polishing machine (manufactured by HAMAI) was used, and urethane foam having a hardness A of 70 degrees was used for the pad. As the abrasive, cerium oxide having an average particle diameter of 60 nm was dispersed in water and used as a slurry. The mixing ratio of water and abrasive was 2: 8. The load per unit area was 90 g / cm 2 , the upper surface plate was rotated at 30 rpm, and the lower surface plate was rotated at 10 rpm. The polishing amount was 3 μm.
　得られたガラス基板の表面粗さはＲｍａｘが５ｎｍ、Ｒａが０．３ｎｍであった。
（９）スクラブ洗浄工程
　第２ポリッシング工程の終了後、図４に示したガラス基板表面とスクラブ部材の回転軸との角度が略０°のスクラブ部材を有するスクラブ洗浄装置３０で１回目のスクラブ洗浄を行い、次に図５に示したガラス基板表面とスクラブ部材の回転軸との角度が略９０°のスクラブ部材を有するスクラブ洗浄装置３１で２回目のスクラブ洗浄を行った。スクラブ洗浄装置３０、３１で用いたスクラブ部材のスポンジとしては、ポリビニルアルコールスポンジを用いた。空隙率は、５０％で、硬度は、４５°（ＪＩＳ　Ｋ７３１２）であった。また、ローラ３０ａ，３０ｂ、３１ａ、３１ｂの回転数は共に３００ｒｐｍとした。またガラス基板１の回転数は２００ｒｐｍとした。洗浄液としては、過酸化水素濃度が０．５質量％の過酸化水素水を用いた。洗浄液の供給は、スプレー噴霧によって、スクラブ洗浄開始３秒前からスクラブ洗浄終了時まで連続して、毎分１００ｍｌの量を供給した。このようにして実施例１のガラス基板１を１００枚作成した。
（実施例２）
　実施例１におけるスクラブ洗浄工程において、図５に示したガラス基板表面とスクラブ部材の回転軸との角度が略９０°のスクラブ部材を有するスクラブ洗浄装置３１で１回目のスクラブ洗浄を行い、次に図４に示したガラス基板表面とスクラブ部材の回転軸との角度が略０°のスクラブ部材を有するスクラブ洗浄装置３０で２回目のスクラブ洗浄を行った。その他は、実施例１と同様に行い、実施例２のガラス基板１を１００枚作成した。
（実施例３）
　実施例１におけるスクラブ洗浄工程において、図８に示すガラス基板表面とスクラブ部材の回転軸との角度が略０°のスクラブ部材と、ガラス基板表面とスクラブ部材の回転軸との角度が略９０°のスクラブ部材とを有するスクラブ洗浄装置３２でスクラブ洗浄を行った。その他は、実施例１と同様に行い、実施例３のガラス基板１を１００枚作成した。
（比較例１）
　実施例１におけるスクラブ洗浄工程において、図４に示したガラス基板表面とスクラブ部材の回転軸との角度が略０°のスクラブ部材を有するスクラブ洗浄装置３０でスクラブ洗浄を１回だけ行った。その他は、実施例１と同様に行い、比較例１のガラス基板１を１００枚作成した。
（比較例２）
　実施例１におけるスクラブ洗浄工程において、図５に示したガラス基板表面とスクラブ部材の回転軸との角度が略９０°のスクラブ部材を有するスクラブ洗浄装置３１でスクラブ洗浄を１回だけ行った。その他は、実施例１と同様に行い、比較例２のガラス基板１を１００枚作成した。
（比較例３）
　実施例１におけるスクラブ洗浄工程において、図４に示したガラス基板表面とスクラブ部材の回転軸との角度が略０°のスクラブ部材を有するスクラブ洗浄装置３０で１回目のスクラブ洗浄を行い、次に、同じ洗浄装置３０で２回目のスクラブ洗浄を行った。その他は、実施例１と同様に行い、比較例３のガラス基板１を１００枚作成した。
（比較例４）
　実施例１におけるスクラブ洗浄工程において、図５に示したガラス基板表面とスクラブ部材の回転軸との角度が略９０°のスクラブ部材を有するスクラブ洗浄装置３１で１回目のスクラブ洗浄を行い、次に、同じ洗浄装置３１で２回目のスクラブ洗浄を行った。その他は、実施例１と同様に行い、比較例４のガラス基板１を１００枚作成した。
（評価）
　実施例１～３と比較例１～４で作製したガラス基板表面を、走査型レーザーディスク表面検査装置を用い、基板表面の付着している異物の個数を評価した。１００枚の付着異物の数の合計を比較例１のものを１として相対評価した。ランクは、付着異物の数が０～０．５を◎、０．５を越えて０．７までを○、０．７を越えて０．８までを△、０．８を越えて１までを×とした。なお付着異物の数が相対値で０．８を超えると磁気ディスクでのヘッドの読み取りエラーの発生が高くなるので０．８以下が製品として要求される。表１に、実施例１～３及び比較例１～４の評価結果を示す。 As for the surface roughness of the obtained glass substrate, Rmax was 5 nm and Ra was 0.3 nm.
(9) Scrub Cleaning Step After the second polishing step, the first scrub cleaning is performed by the scrub cleaning device 30 having a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member shown in FIG. Next, scrub cleaning was performed for the second time by the scrub cleaning device 31 having a scrub member whose angle between the glass substrate surface and the rotation axis of the scrub member shown in FIG. As the sponge of the scrub member used in the scrub cleaning devices 30 and 31, polyvinyl alcohol sponge was used. The porosity was 50% and the hardness was 45 ° (JIS K7312). The rotation speeds of the rollers 30a, 30b, 31a, and 31b were all 300 rpm. The rotation speed of the glass substrate 1 was 200 rpm. As the cleaning liquid, hydrogen peroxide having a hydrogen peroxide concentration of 0.5% by mass was used. The cleaning liquid was supplied by spraying in an amount of 100 ml per minute continuously from 3 seconds before the start of scrub cleaning until the end of scrub cleaning. Thus, 100 glass substrates 1 of Example 1 were produced.
(Example 2)
In the scrub cleaning process in Example 1, the scrub cleaning device 31 having a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member shown in FIG. A second scrub cleaning was performed with the scrub cleaning device 30 having a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member shown in FIG. Others were performed in the same manner as in Example 1, and 100 glass substrates 1 of Example 2 were produced.
(Example 3)
In the scrub cleaning process in Example 1, the scrub member whose angle between the glass substrate surface and the rotation axis of the scrub member shown in FIG. 8 is approximately 0 °, and the angle between the glass substrate surface and the rotation axis of the scrub member is approximately 90 °. Scrub cleaning was performed by a scrub cleaning device 32 having a scrub member. Others were performed in the same manner as in Example 1, and 100 glass substrates 1 of Example 3 were produced.
(Comparative Example 1)
In the scrub cleaning process in Example 1, scrub cleaning was performed only once with the scrub cleaning apparatus 30 having a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member of approximately 0 ° shown in FIG. Others were performed in the same manner as in Example 1, and 100 glass substrates 1 of Comparative Example 1 were produced.
(Comparative Example 2)
In the scrub cleaning process in Example 1, scrub cleaning was performed only once with the scrub cleaning device 31 having a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member of approximately 90 ° shown in FIG. Others were performed in the same manner as in Example 1, and 100 glass substrates 1 of Comparative Example 2 were prepared.
(Comparative Example 3)
In the scrub cleaning process in Example 1, the scrub cleaning device 30 having a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member shown in FIG. The second scrub cleaning was performed with the same cleaning device 30. Others were performed in the same manner as in Example 1, and 100 glass substrates 1 of Comparative Example 3 were prepared.
(Comparative Example 4)
In the scrub cleaning process in Example 1, the scrub cleaning device 31 having a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member shown in FIG. The second scrub cleaning was performed with the same cleaning device 31. Others were performed in the same manner as in Example 1, and 100 glass substrates 1 of Comparative Example 4 were prepared.
(Evaluation)
The glass substrate surfaces produced in Examples 1 to 3 and Comparative Examples 1 to 4 were evaluated using a scanning laser disk surface inspection apparatus to evaluate the number of foreign substances adhering to the substrate surface. The total number of adhering foreign substances on 100 sheets was evaluated relative to that of Comparative Example 1 as 1. The rank is ◎ when the number of adhered foreign substances is 0 to 0.5, ○ over 0.5 to 0.7, over 0.7 to 0.8, over 0.8 to 1 X. If the number of adhering foreign matters exceeds 0.8 in relative value, the occurrence of head read errors on the magnetic disk becomes high, so 0.8 or less is required as a product. Table 1 shows the evaluation results of Examples 1 to 3 and Comparative Examples 1 to 4.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１の実施例１～３の結果から、ガラス基板表面とスクラブ部材の回転軸との角度が略０°のスクラブ部材と略９０°のスクラブ部材を用いて洗浄することにより、ガラス基板表面に付着した異物を確実に除去できることがわかる。また、実施例１、２と実施例３とを比較すると、図８のように略０°のスクラブ部材と略９０°のスクラブ部材を用いて同時に行う洗浄方法よりも、別々に行う方が好ましいことがわかる。また、比較例１～４の結果からは、略０°又は略９０°のスクラブ部材を用いた１回の洗浄では、十分にガラス基板表面の異物を除去することができず、また、同じ角度のスクラブ部材を２回行っても、まだ、異物の除去は不十分であった。 From the results of Examples 1 to 3 in Table 1, the glass substrate surface was cleaned by using a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member of about 0 ° and a scrub member of about 90 °. It can be seen that the adhered foreign matter can be reliably removed. In addition, when Examples 1 and 2 are compared with Example 3, it is preferable to perform the cleaning separately rather than the cleaning method that uses the scrub member of approximately 0 ° and the scrub member of approximately 90 ° simultaneously as shown in FIG. I understand that. Further, from the results of Comparative Examples 1 to 4, it is not possible to sufficiently remove the foreign matter on the glass substrate surface by one cleaning using a scrub member of approximately 0 ° or approximately 90 °, and the same angle. Even if the scrubbing member was performed twice, the removal of foreign matter was still insufficient.

Claims (10)

  1. ガラス基板表面を回転するスクラブ部材を用いて洗浄するスクラブ洗浄工程を有する情報記録媒体用ガラス基板の製造方法において、
    前記スクラブ洗浄工程は、前記ガラス基板表面に対して回転軸の方向の異なる２種類のスクラブ部材で洗浄を行い、
    そのうちの一方のスクラブ部材による洗浄は、前記ガラス基板表面と前記スクラブ部材の回転軸との角度が、略０°であり、
    もう一方のスクラブ部材による洗浄は、前記ガラス基板表面と前記スクラブ部材の回転軸との角度が、略９０°であることを特徴とする情報記録媒体用ガラス基板の製造方法。     In the method for manufacturing a glass substrate for an information recording medium having a scrub cleaning step of cleaning using a scrub member that rotates the surface of the glass substrate,
    In the scrub cleaning step, cleaning is performed with two types of scrub members having different rotation axis directions with respect to the glass substrate surface,
    In cleaning with one of the scrub members, the angle between the glass substrate surface and the rotation axis of the scrub member is approximately 0 °,
    The method for producing a glass substrate for an information recording medium is characterized in that the cleaning with the other scrub member is such that the angle between the surface of the glass substrate and the rotation axis of the scrub member is approximately 90 °.
  2. 前記回転軸の方向の異なる２種類のスクラブ部材による洗浄は、一方のスクラブ部材による洗浄後に、もう一方のスクラブ部材による洗浄を行うことを特徴とする請求の範囲第１項に記載の情報記録媒体用ガラス基板の製造方法。 2. The information recording medium according to claim 1, wherein the cleaning with the two types of scrub members having different directions of the rotating shaft is performed by cleaning with the other scrub member after the cleaning with one scrub member. Method for manufacturing glass substrate.
  3. 前記回転軸の方向の異なる２種類のスクラブ部材による洗浄は、一方のスクラブ部材による洗浄と、もう一方のスクラブ部材による洗浄を同時に行うことを特徴とする請求の範囲第１項に記載の情報記録媒体用ガラス基板の製造方法。 2. The information recording according to claim 1, wherein the cleaning with the two types of scrub members having different directions of the rotating shaft simultaneously performs cleaning with one scrub member and cleaning with the other scrub member. A method for producing a glass substrate for a medium.
  4. 前記スクラブ洗浄工程は、前記ガラス基板に洗浄液を供給し、前記スクラブ部材で洗浄を行うことを特徴とする請求の範囲第１項から第３項の何れか１項に記載の情報記録媒体用ガラス基板の製造方法。 The glass for an information recording medium according to any one of claims 1 to 3, wherein in the scrub cleaning step, a cleaning liquid is supplied to the glass substrate and cleaning is performed with the scrub member. A method for manufacturing a substrate.
  5. 前記ガラス基板表面を垂直にして、前記回転方向の異なる２種類のスクラブ部材のうち、前記ガラス基板表面と前記スクラブ部材の回転軸との角度が略９０°のスクラブ部材を、前記ガラス基板表面と前記スクラブ部材の回転軸との角度が略０°のスクラブ部材よりも、鉛直方向上方に配置することを特徴とする請求の範囲第３項に記載の情報記録媒体用ガラス基板の製造方法。 Of the two types of scrub members having different rotation directions with the glass substrate surface vertical, a scrub member having an angle between the glass substrate surface and the rotation axis of the scrub member of approximately 90 ° is defined as the glass substrate surface. 4. The method for producing a glass substrate for an information recording medium according to claim 3, wherein the scrub member is disposed vertically above a scrub member having an angle with a rotation axis of the scrub member of approximately 0 °.
  6. 前記スクラブ洗浄工程は、前記ガラス基板を支持しかつ回転させる支持ローラにより、前記ガラス基板を回転させながら、前記スクラブ部材で洗浄を行うことを特徴とする請求の範囲第１項から第５項の何れか１項に記載の情報記録媒体用ガラス基板の製造方法。 6. The scrub cleaning process according to claim 1, wherein the scrubbing step performs cleaning with the scrub member while rotating the glass substrate by a support roller that supports and rotates the glass substrate. The manufacturing method of the glass substrate for information recording media of any one.
  7. 前記情報記録媒体用ガラス基板の製造方法は、前記ガラス基板表面を研磨する研磨工程を有し、
    該研磨工程の後に、前記ガラス基板表面をスクラブ洗浄することを特徴とする請求の範囲第１項から第６項の何れか１項に記載の情報記録媒体用ガラス基板の製造方法。     The manufacturing method of the glass substrate for information recording medium has a polishing step of polishing the glass substrate surface,
    The method of manufacturing a glass substrate for an information recording medium according to any one of claims 1 to 6, wherein the glass substrate surface is scrubbed after the polishing step.
  8. 前記スクラブ部材が表面にスポンジを有する回転ローラであり、該回転ローラを前記ガラス基板表面に接触させてスクラブ洗浄を行うことを特徴とする請求の範囲第１項から第７項の何れか１項に記載の情報記録媒体用ガラス基板の製造方法。 The scrub member is a rotating roller having a sponge on the surface, and scrub cleaning is performed by bringing the rotating roller into contact with the surface of the glass substrate. The manufacturing method of the glass substrate for information recording media as described in 2 ..
  9. 請求の範囲第１項から第８項の何れか１項に記載の製造方法により製造されたことを特徴とする情報記録媒体用ガラス基板。 A glass substrate for an information recording medium, which is manufactured by the manufacturing method according to any one of claims 1 to 8.
  10. 請求の範囲第９項に記載の情報記録媒体用ガラス基板の表面に磁性膜を有することを特徴とする磁気記録媒体。 A magnetic recording medium comprising a magnetic film on the surface of the glass substrate for an information recording medium according to claim 9.
PCT/JP2009/050116 2008-01-22 2009-01-08 Method of manufacturing glass substrate for information recording medium, glass substrate for information recording medium, and magnetic recording medium WO2009093484A1 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110508526A (en) * 2019-08-29 2019-11-29 金苡炫 A kind of efficient Ultrasonic-B probe cleaning equipment

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JP2001096245A (en) * 1999-09-29 2001-04-10 Systemseiko Co Ltd Cleaning method and cleaning equipment
JP2001150336A (en) * 1999-11-22 2001-06-05 Systemseiko Co Ltd Manufacturing method and polishing method for flat plate-shaped substrate
JP2001294433A (en) * 2000-04-12 2001-10-23 Matsushita Electric Ind Co Ltd Method for manufacturing press forming die

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001096245A (en) * 1999-09-29 2001-04-10 Systemseiko Co Ltd Cleaning method and cleaning equipment
JP2001150336A (en) * 1999-11-22 2001-06-05 Systemseiko Co Ltd Manufacturing method and polishing method for flat plate-shaped substrate
JP2001294433A (en) * 2000-04-12 2001-10-23 Matsushita Electric Ind Co Ltd Method for manufacturing press forming die

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110508526A (en) * 2019-08-29 2019-11-29 金苡炫 A kind of efficient Ultrasonic-B probe cleaning equipment

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