JP2000288922A - Polishing carrier, polishing method and manufacture of information recording medium substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the danger of damaging the end surface of a work to be polished in polishing by constituting at least the inner circumferential part of a holding hole to make contact with the work by use of a material having a specified hardness or less. SOLUTION: A plurality of work holding holes 2a-2g is formed on a work holding part 2. At least the inner circumferential part of the work holding holes 2a-2g to make contact with a work to be polished is formed of a material having a hardness of 100 or less (Asker-C). For example, as the intermediate member to make contact with the end surface of the work, polyurethane material is used. The material of the intermediate member is preferably softer than an abrasive pad used in polishing process. According to this, the danger of damaging the end surface of a magnetic recording medium glass substrate can be effectively eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a magnetic disk substrate,
Polishing carrier for holding a polished body when polishing a polished body such as a substrate for an optical disk or a silicon wafer, a substrate for an electronic device (a substrate for a photomask blank, a substrate for a phase shift mask blank, a substrate for a liquid crystal display). And a polishing method using the polishing carrier, and a method for manufacturing a substrate for an information recording medium using the polishing method.

[0002]

2. Description of the Related Art Generally, in polishing or lapping of a disk-shaped glass substrate used for a substrate for a magnetic disk or the like, a glass substrate is put into a plurality of circular holding holes provided in a disk-shaped polishing carrier. This is performed by rotating the upper and lower platens in opposite directions while holding the glass substrate between the lower platen and the upper platen of the polishing apparatus. Here, a gear is formed on the outer peripheral portion of the polishing carrier, and this gear meshes with an internal gear and a sun gear of the polishing apparatus. Therefore, the polishing carrier performs a planetary motion due to a difference in the number of rotations between the internal gear and the sun gear, whereby the glass substrate is simultaneously polished or lapped on both sides.

As the above polishing carrier, for example,
As disclosed in Japanese Patent Application Laid-Open No. Hei 8-300565, a prepreg obtained by impregnating and drying a glass woven fabric with an epoxy resin is stacked in a predetermined number and heated and pressed integrally.

On the other hand, a glass substrate for a magnetic disk or the like has the following problems if the end surface (outer peripheral side surface) of the glass substrate is not mirrored. That is, when a glass substrate for a magnetic disk or a glass magnetic disk is put in and taken out of a storage container made of polycarbonate or the like, the inner peripheral surface of the storage container comes into contact with the end surface of the glass substrate, and particles generated from the end surface generate particles or glass particles. It adheres to the surface of the magnetic disk, which may cause thermal asperity.

Therefore, in order to prevent the occurrence of the thermal asperity, the end surface (outer peripheral side surface) of the glass substrate is mirror-finished. Generally, the mirror finishing process of the glass substrate end surface is based on the difference in required surface roughness (the surface roughness of the main surface is smaller than the surface roughness of the end surface). This is performed before the polishing step because the particle diameter of the abrasive grains used in the mirror finishing step of the end face is larger than the particle diameter of the abrasive grain.

[0006]

However, when polishing is performed using the above-mentioned polishing carrier, the glass substrate end face once mirror-finished in the mirror polishing step of the glass substrate end face becomes a glass substrate inside the polishing carrier. It was confirmed that the rubbing caused streak-like scratches called mottled end faces. Even in the case of a glass substrate having a mottled end surface, dust is generated due to the contact with the storage container described above, which causes a problem of causing thermal asperity.

SUMMARY OF THE INVENTION The present invention has been made under the above-mentioned background, and a polishing carrier and a polishing carrier which do not cause a flaw or the like on an end face (outer peripheral side face) of an object to be polished in a polishing process or the like. An object of the present invention is to provide a polishing method used and a method for manufacturing a substrate for an information recording medium using the polishing method.

[0008]

According to a first aspect of the present invention, there is provided a polishing carrier having a holding hole for holding an object to be polished, wherein the holding hole is in contact with at least the object to be polished. Has a hardness of 100 or less (A
(Sker-C).

According to a second aspect of the present invention, there is provided the polishing carrier according to the first aspect, wherein the material is made of any one of urethane, suva, polycarbonate, vinyl chloride, and rubber.

According to a third aspect of the present invention, an object to be polished is placed in a plurality of holding holes provided in a polishing carrier, and the upper and lower platens are rotated while the object to be polished is held between a lower surface plate and an upper surface plate. In the polishing method of lapping and / or polishing the main surface of the object to be polished and mirror-polishing the main surface of the object to be polished, at least an inner peripheral portion of the holding hole that comes into contact with the object to be polished is subjected to a polishing step. This is a polishing method characterized by being made of a material softer than a polishing pad to be used.

A fourth invention is the polishing method according to the third invention, wherein the material has a hardness of 100 or less (Asker-C).

A fifth invention is the polishing method according to the third or fourth invention, wherein the object to be polished is made of glass or silicon.

According to a sixth aspect of the present invention, an information recording medium substrate is placed in a plurality of polished body holding holes provided in a polishing carrier, and the lower and upper platens sandwich the polished body vertically. A method for manufacturing a substrate for an information recording medium, comprising: a polishing step of rotating a board and lapping and / or polishing the main surface of the information recording medium substrate to mirror-polish the main surface of the information recording medium substrate. At least an inner peripheral portion of the polished body holding hole which is in contact with the information recording medium substrate is formed of a material softer than a polishing pad used in a polishing step. Is the way.

According to a seventh aspect of the present invention, after polishing the end face of the information recording medium substrate, the information recording medium substrate is put into a plurality of holding holes provided in the polishing carrier, and the lower and upper platens are used. An information recording medium substrate having a polishing step of polishing the information recording medium substrate by lapping and / or polishing the main surface of the information recording medium substrate by rotating the upper and lower platens while holding the object to be polished; Wherein at least an inner peripheral portion of the polished body holding hole which is in contact with the information recording medium substrate is formed of a material softer than a polishing pad used in a polishing step. This is a method for manufacturing a medium substrate.

[0015]

(Embodiment 1) FIG. 1 is a plan view of a polishing carrier according to Embodiment 1 of the present invention, and FIG.
FIG. 3 is a sectional view taken along the line I-II, FIG. 3 is a view showing a state in which the polishing carrier is mounted on the polishing apparatus, and FIG. 4 is a partial sectional view in FIG. Hereinafter, Embodiment 1 will be described with reference to these drawings.
A polishing carrier, a polishing method, and a method for manufacturing a substrate for an information recording medium according to the present invention will be described. In this example,
This is an example in which the present invention is applied to a case where a glass substrate for a 2.5-inch magnetic recording medium (a glass substrate for an information recording medium = a body to be polished) is manufactured.

In FIG. 1, a polishing carrier 1 is composed of a disc-shaped polished body holding section 2 and a gear section 3 fitted and fixed to the outer periphery of the polished body holding section. A plurality of polished body holding holes 2a to 2g are formed in the polished body holding portion 2. Each of the polished body holding holes 2a to 2g has a size (inner diameter of about 65 m) capable of accommodating the 2.5-inch magnetic recording medium glass substrate 4 (information recording medium glass substrate = polished body).
m).

The holder 2 has a structure in which a plurality of members are integrally laminated and fixed. That is, as shown in FIG. 2, the intermediate member 21 is sandwiched between the upper member 22 and the lower member 23 to form a sandwich structure and is adhered and fixed. In this embodiment, a urethane material having a thickness of about 0.35 mm is used as the intermediate member 21, and an aramid material having a thickness of about 0.1 mm, which is a harder material than the urethane material, is used as the upper member 22 and the lower member 23. Fiber resin is used.

In this case, the intermediate member 21 and the upper member 22
The lower member 23 is provided with through-holes forming the polished body holding holes 2a to 2g, and the diameter of the through-hole (about 65 mm) of the intermediate member 21 is set to the upper member 22 and the lower member 2.
3 is slightly smaller than the hole diameter (about 67 mm) formed (see FIG. 2).

Therefore, as shown in FIG. 2, the end face (outer peripheral side face) 41 of the glass substrate 4 for a magnetic recording medium contacts only the relatively soft intermediate member (urethane layer) 21,
The hard upper member 22 and the lower member 23 (aramid fiber resin layer) are not in contact with each other. This allows
During polishing, the end surface (outer peripheral side surface) 41 of the glass substrate 4 for a magnetic recording medium is effectively prevented from being damaged.

The gear section 3 is provided with a sun gear 5 in the polishing apparatus.
In order to mesh with the internal gear 6 (see FIG. 3) and rotate it, it is made of stainless steel having good mechanical durability and abrasion resistance, and its inner peripheral end surface is bonded to the outer peripheral end surface of the polished body holding portion 2. Is fixed.

In the above example, a urethane material is used as the intermediate member 21 that comes into contact with the end surface of the object to be polished. However, the material of the intermediate member 21 is softer than the polishing pad used in the polishing step. Any material may be used. Examples of such a material include materials such as suva, polycarbonate, vinyl chloride, and rubber.

Hardness of polishing pad used for polishing or lapping (Asker-C)
Is 150 to 100, the hardness of the intermediate member 21 is 10
It is preferably 0 or less (Asker-C). The hardness (Asker-C) of each material described above is 60 to 82.
(Urethane), 61-95 (Suva), polycarbonate, Rockwell hardness M75 (vinyl chloride), and Rockwell hardness C112 (rubber). As a material of the intermediate member 21, rubber is also suitable in terms of adhesiveness to the upper member 22 and the lower member 23 and flexibility.

Although the upper member 22 and the lower member 23 are made of aramid fiber resin as a material for the member 23, this is a material harder than the intermediate member 21 and is used for polishing or lapping. Any material can be used as long as the surface accuracy of the object to be polished is high. For example, a material such as FRP (glass epoxy) or SUS (stainless steel) can be used.

The example in which the intermediate member 21 and the upper member 22 and the lower member 23 are fixed with an adhesive has been described, but this can also be fixed by press molding.

Further, the thickness of the polishing carrier 1 is appropriately adjusted depending on the thickness of a glass substrate or the like to be finally polished. In the case of a 2.5-inch glass substrate, since the thickness of the glass substrate is 0.635 ± 0.015 mm, it is preferable to set the thickness to about 0.55 to 0.60 mm. It is more preferable that the thickness of the intermediate member 21 of the polishing carrier 1 that comes into contact with the object to be polished, such as a glass substrate, is larger than the length (other than the chamfered portion) of the end surface (outer peripheral side surface) of the glass substrate.

Next, referring to FIGS. 3 and 4, the polishing carrier 1 is mounted on the polishing apparatus 5 and the glass substrate 4 for the magnetic recording medium, which is the object to be polished, is subjected to polishing or lapping. Will be described briefly.

The polishing apparatus 5 includes an internal gear 51 and a sun gear 52, each of which is driven to rotate at a predetermined rotation ratio.
And an upper surface plate 53 and a lower surface plate 54 which are driven to rotate in opposite directions with respect to the polishing carrier mounting portion.

When a plurality of polishing carriers 1 are set in the polishing carrier mounting portion, the gears of these polishing carriers 1 mesh with the internal gear 51 and the sun gear 52. When the glass substrate 4 for a magnetic recording medium, which is the object to be polished, is set in the object holding holes 2a to 2g of each polishing carrier 1 and polishing is started, the polishing carrier 1 rotates with the internal gear 51 and the sun gear 52. The planetary motion is performed by the number difference. At the same time, the upper surface plate 53 and the lower surface plate 54 rotate in opposite directions, and the front and back surfaces of the magnetic recording medium glass substrate 4 are polished or wrapped by the polishing pads 53a and 54a provided thereon.

Generally, a glass substrate is mirror-finished through a process of roughing → lapping (sanding) → end surface mirroring process → polishing process. Here, the lapping step aims at improving dimensional accuracy and shape accuracy, and the main surface of the glass substrate is processed by a lapping machine. The polishing step aims at improving the smoothness of the surface (reducing the surface roughness) and reducing the processing strain, and usually includes a first polishing step using a hard polisher and a second polishing step using a soft polisher.
A polishing step (final polishing step).

Although the polishing carrier of the present invention can be used in any of the above-mentioned steps, the greatest effect can be obtained by using the polishing carrier in a polishing step after the lapping step after the mirror polishing step of the end face. Is exhibited.
Therefore, the polishing process will be specifically described below.

When performing the polishing process (first polishing step, final polishing step), the gear 3 formed on the outer peripheral portion of the polishing carrier 1 was engaged with the sun gear 52 and the internal gear 51 of the polishing apparatus 5. In this state, the polishing carrier 1 is set on the lower platen 54 to which the polishing pad 54a of the polishing apparatus 5 is attached. Next, the polishing object holding hole 2a
The glass substrate 4 for a magnetic recording medium, which is the object to be polished, is put into and held in the glass substrate 4 to 2 g.

Next, the glass substrate 4 is placed on a polishing pad 54a.
The lower platen 54 and the upper platen 53 are sandwiched between the lower platen 54 and the upper platen 53 on which the polishing pad 53a is stuck, and the lower platen 54 and the upper platen 53 are rotated in opposite directions while supplying a polishing liquid containing abrasive grains such as cerium oxide. . Thereby, the polishing carrier 1 revolves while rotating by the difference in the rotation speeds of the sun gear 52 and the internal gear 51, and both surfaces of the glass substrate 4 are simultaneously polished.

During the polishing step, the glass substrate 4 rotates within the holding holes 2a to 2g, or
g Although it rubs against the inner peripheral portion, since the intermediate member 21 holding the glass substrate 4 is a soft material, the end surface of the glass substrate 4 is not damaged.

The polishing pads 53 and 54 include, for example, a soft polisher made of suede and velor, and a hard polisher such as hard velor, urethane foam, and pitch impregnated suede.

Hereinafter, the manufacturing process of the glass substrate for a magnetic recording medium will be described more specifically. (1) First Lapping Step (First Sanding Step) First, a glass substrate made of aluminosilicate glass cut into a disk shape having a diameter of 66 mmφ and a thickness of 1.1 mm with a grinding wheel from a sheet glass formed by a downdraw method. Was ground with a relatively coarse diamond grindstone to form a diameter of 65 mm (2.5 inches) φ and a thickness of 0.6 mm.

In this case, instead of the down-draw method, the molten glass may be directly pressed using an upper mold, a lower mold, and a body mold to obtain a disk-shaped glass body. Incidentally, as the aluminosilicate glass, 5% of SiO ₂ was expressed in mol%.
7-74%, ZnO ₂ is 0-2.8%, Al ₂ O ₃ is 3
15%, the LiO ₂ 7 to 16%, a Na ₂ O 4 to 14
%, As a main component.

Next, the glass substrate was subjected to a lapping process. This lapping step aims at improving dimensional accuracy and shape accuracy. The lapping process was performed using a lapping apparatus, and a carrier made of aramid fiber was used, and the grain size of abrasive grains was set to # 400. Specifically, alumina load of particle size # 400 was used, and load L was 10
By setting the sun gear and the internal gear to about 0 kg and rotating both the sun gear and the internal gear, both surfaces of the glass substrate housed in the carrier have a surface accuracy of 0 to 1 μm and a surface roughness (Rmax).
(Measured by JIS B0601) Lapping was performed to about 6 μm.

Next, a circular hole (diameter: 20 mmφ) was opened in the center of the glass substrate using a cylindrical grindstone, and a predetermined chamfer was applied to the outer peripheral end surface and the inner peripheral end surface. At this time, the surface roughness of the inner and outer peripheral end faces of the glass substrate is Rmax
Was about 14 μm.

(2) Edge Polishing Step Next, the edge portion (angular portion, side surface and chamfered portion) of the glass substrate is polished while rotating the glass substrate by brush polishing with cerium oxide abrasive having an average particle size of about 3 μm. To make the angular portion a curved surface with a radius of 0.2 to 10 mm, and their surface roughness to 1 μm in Rmax,
Ra was about 0.3 μm. The surface of the glass substrate after the end face polishing step was washed with water.

(3) Second Lapping Step (Second Sanding Step) Next, using the carrier of Example 1 in which the intermediate member 21 is made of urethane (hardness 95 (Asker-C)) using a lapping apparatus, The lapping is performed by rotating the sun gear and the internal gear with the alumina abrasive having a particle size of # 1000 (particle size of about 3 μm) and the load L set to about 100 kg, and the surface roughness (Rma) on both surfaces of the glass substrate is set.
x) was about 2 μm. The glass substrate after the second lapping step was washed by sequentially immersing the glass substrate in a neutral detergent and water washing tank.

(4) First Polishing Step (First Polishing Step) Next, a first polishing step was performed. This first polishing step is intended to remove scratches and distortion remaining in the above-described lapping step, and was performed using a polishing apparatus. Specifically, a hard polisher (Cerium Pad MHC15: manufactured by Speed Fam) is used as a polishing pad (polishing cloth), and the holding member 4 is made of a rubber (hardness 82 (A)).
A first polishing step was performed under the following polishing conditions using the carrier of Example 1 composed of Sker-C)).

Polishing liquid: cerium oxide (average particle size: 1.3 μm) + water Load: 300 kg / cm 2 (L = 238 kg) Polishing time: 15 minutes Removal amount: 30 μm Lower platen rotation speed: 40 rpm Upper platen rotation speed: 35 rpm Sun gear rotation speed: 14 rpm Internal gear rotation speed: 29 rpm The glass substrate that has been subjected to the first polishing step is placed in a cleaning tank of a neutral detergent, pure water, pure water, IPA (isopropyl alcohol), and IPA (steam drying). Soak sequentially,
Washed.

(5) Second Polishing Step (Final Polishing Step) Next, using the polishing apparatus used in the first polishing step, the polishing pad was changed from a hard polisher to a soft polisher (Porelax: manufactured by Speed Fam). The second polishing step was performed using the carrier of Example 1 in which the intermediate member 21 was made of a suba (hardness 61 (Asker-C)). The polishing conditions were the same as in the first polishing step except that the polishing liquid was cerium oxide (average particle size: 0.8 μm), the load was 100 g / cm 2, the polishing time was 5 minutes, and the removal amount was 5 μm. The glass substrate after the second polishing step is washed with a neutral detergent, a neutral detergent, pure water, pure water,
Washing was performed by sequentially immersing in each of IPA (isopropyl alcohol) and IPA (steam drying) washing tanks. In addition, ultrasonic waves were applied to each cleaning tank.

(6) Chemical Strengthening Step Next, the glass substrate after the lapping and polishing steps was chemically strengthened. For the chemical strengthening, a chemical strengthening solution in which potassium nitrate (60%) and sodium nitrate (40%) are mixed is prepared, and the chemical strengthening solution is heated to 400 ° C., and the cleaned glass substrate preheated to 300 ° C. is washed. 3
It was carried out by soaking for a time. In this immersion, in order to chemically strengthen the entire surface of the glass substrate, the immersion was performed in a state where a plurality of glass substrates were housed in a holder so as to be held at end faces.

As described above, by immersion treatment in the chemical strengthening solution, lithium ions and sodium ions on the surface layer of the glass substrate can be replaced with sodium ions in the chemical strengthening solution.
The glass substrate is strengthened by being respectively substituted by potassium ions. The thickness of the compressive stress layer formed on the surface of the glass substrate was about 100 to 200 μm. The glass substrate after the chemical strengthening is immersed in a water bath at 20 ° C. and rapidly cooled,
Maintained for about 10 minutes. After the quenched glass substrate,
Washing was performed by immersion in concentrated sulfuric acid heated to about 40 ° C. Further, the glass substrate after the sulfuric acid cleaning is purified water, pure water,
Washing was performed by sequentially immersing in each of IPA (isopropyl alcohol) and IPA (steam drying) washing tanks. In addition, ultrasonic waves were applied to each cleaning tank.

(Evaluation) The surface roughness Ra of the outer peripheral end surface of the glass substrate for a magnetic recording medium obtained through the above steps was 0.0
It was 3 μm. The surface roughness Ra of the main surface of the glass substrate was 0.3 to 0.7 nm (measured by AFM (atomic force microscope)). When the surface of the end face was observed with an electron microscope (4000 times), the end face was in a mirror state, and no mottle was generated on the end face.

(7) Magnetic Disk Manufacturing Process A NiAl seed layer, a CrMo underlayer, a CoPtCr layer were formed on both surfaces of a magnetic disk glass substrate selected through the above-described processes using an in-line sputtering apparatus.
A Ta magnetic layer and a hydrogenated carbon protective layer were sequentially formed, and a perfluoropolyether liquid lubricating layer was formed by dipping to obtain a magnetic disk.

When a glide test was performed on the obtained magnetic disk, no hit (the head touches a protrusion on the magnetic disk surface) or crash (the head collides with the protrusion on the magnetic disk surface) was not recognized. Was. In addition, it was confirmed that no defect occurred in the film such as the magnetic layer due to particles that cause thermal asperity, and the magnetoresistive head (MR head) was used.
A reproduction test was performed on the sample, but no malfunction of reproduction due to thermal asperity was observed for all of the plurality of samples (500 sheets).

(Comparative Example 1) In the second lapping step and the polishing step (first and final), the holder 2 to be polished was made of aramid fiber resin (hardness; Rockwell HRL122 to HRF84 (Asker-C)). A glass substrate for a magnetic recording medium was produced in the same manner as in the above example except that the glass substrate had a layer structure.

As a result, the surface roughness of the main surface of the glass substrate was almost the same, but the outer peripheral end face was taken with an electron microscope (4000).
2), spot-like flaws on the end face of the scratch were observed. In the same manner as described above, a glide test was performed on the obtained magnetic disk. As a result, no hit or crash occurred, but it was confirmed that a defect occurred in the film such as the magnetic layer. A reproduction test was performed on this magnetic disk with a magnetoresistive head (MR head). As a result, for 12 of a plurality of samples (500), a reproduction malfunction considered to be due to thermal asperity was confirmed.

FIGS. 5 to 8 are cross-sectional views of a main part of a polishing carrier according to another embodiment of the present invention. Hereinafter, FIGS. 5 to 8
Another embodiment will be described with reference to FIG.

In the example shown in FIG. 5, the object-to-be-polished holder 2 is formed of one layer of a hard material 24, and each of the object-to-be-polished holding holes 2a to 2a.
This is an example in which a ring body 24a of a soft material is bonded and fixed to the inner peripheral surface of 2 g.

In the example shown in FIG. 6, the object-to-be-polished holder 2 is formed of one layer of a hard material 25, and each of the object-to-be-polished holding holes 2a to 2a.
An inner peripheral surface of 2 g is formed into a concave curved surface, and a ring member 25 of a soft material whose inner peripheral surface is flattened is formed on the concave curved surface portion.
This is an example in which a is fitted and fixed.

The example shown in FIG.
Is formed by laminating and fixing the upper member 26, the intermediate member 27, and the lower member 26 made of a hard material. Only the hole diameter of the intermediate member 27 is formed slightly smaller, and the polished body holding holes 2a to 2g are formed. A ring body 2 made of a soft material having an intermediate member 27 protruding from an inner peripheral surface thereof and a protruding portion provided with a depression on the outer periphery.
7a is fitted and fixed.

In the example shown in FIGS. 7 and 8 described above, the intermediate member 27 is preferably made of a material that increases mechanical strength in the vertical and horizontal directions and as a gear and generates less dust. For example, SUS (stainless steel) (hereinafter, referred to as SU), aramid fiber (hereinafter, referred to as AR), glass epoxy (hereinafter, referred to as EG), or the like can be used.

The upper member 26 and the lower member 26 are preferably made of a material which has good contact with the upper and lower platens and which has low abrasion. Examples thereof include polycarbonate (hereinafter, referred to as PC), tetron, and vinyl chloride. (Hereinafter referred to as polyvinyl chloride) can be used.

Upper member 26, intermediate member 27, lower member 2
6 is (upper / middle / lower) = (P
C / SU / PC), (PC / EG / PC), (PC / A
R / PC), (Tetron / SU / Tetron), (Tetron / EG / Tetron), (Tetron / AR / Tetron), (PVC / SU / PVC), (PVC / EG / PVC),
(PVC / AR / PVC). )

The example shown in FIG.
Is formed by laminating and fixing the upper member 26, the intermediate member 27, and the lower member 26 made of a hard material, and only the hole diameter of the intermediate member 27 is formed slightly larger, and the polished body holding holes 2a to 2g are formed. A recess is formed in the inner peripheral surface, and a ring body 27b made of a soft material is fitted and fixed in the recess, and the ring body 27b is projected from the inner peripheral surface of the polished body holding holes 2a to 2g. .

Further, in addition to the above example, at least a portion in contact with the object to be polished is made of a soft material (having a hardness of 100 or less (A
Sker-C)) may be in any form as long as it is formed. Further, the portion that comes into contact with the object to be polished is not necessarily required to be flat, but may be trapezoidal or rounded.

Although glass has been described as a material of the object to be polished, the material is not limited to this, and brittle materials such as glass ceramics, ceramics, silicon, and carbon, and metals such as aluminum may be used. I do not care.
In addition, a disk-shaped substrate has been described as a shape of the object to be polished,
The present invention is not limited to this, and may be rectangular. In this case, the holding holes of the carrier have a rectangular shape having substantially the same size. Also,
The shape is not limited to the substrate shape, and may be a block shape.

In the above-described embodiment, the polishing carrier of the present invention was used in all the steps (lapping step and polishing step) after the end face polishing step. However, the present invention is not limited to this. It may be used only in the lapping step using abrasive grains having a large particle diameter.
This is because it is considered that the formation of the end face mottled by the abrasive grains is not formed by the polishing step using the abrasive grains having a small particle diameter of the abrasive grains used in the end face mirror polishing step. In order to suppress the occurrence of end face mottle due to the inner peripheral portion of the holding hole, the polishing carrier of the present invention may be used in the polishing step as in the above-described embodiment.

[0062]

As described in detail above, the present invention relates to a polishing carrier having a holding hole for holding an object to be polished, wherein at least an inner peripheral portion of the holding hole which is in contact with the object to be polished has a hardness of 100%. The polishing carrier is characterized by being made of the following material (Asker-C), whereby the polishing carrier and the polishing carrier are not likely to cause a flaw or the like on the end face (outer peripheral side face) of the object to be polished in polishing or the like. A polishing method using a carrier and a method for manufacturing a substrate for an information recording medium using the polishing method have been obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a polishing carrier according to Example 1 of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a view showing a state in which a polishing carrier is mounted on a polishing apparatus.

FIG. 4 is a partial sectional view of FIG.

FIG. 5 is a sectional view of a main part of another embodiment of the present invention.

FIG. 6 is a sectional view of a main part of another embodiment of the present invention.

FIG. 7 is a sectional view of a main part of another embodiment of the present invention.

FIG. 8 is a sectional view of a main part of another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Polishing carrier, 2 ... Polishing object holding part, 3 ... Gear part, 4 ... Glass substrate for magnetic recording media, 5 ... Polishing device, 2
a to 2 g: Polishing object holding hole.

Claims (7)

[Claims] 1. A polishing carrier having a holding hole for holding an object to be polished, wherein at least an inner peripheral portion of the holding hole in contact with the object to be polished has a hardness of 100 or less (Aske).
A polishing carrier comprising a material of rC). 2. The polishing carrier according to claim 1, wherein the material is made of any one of urethane, suva, polycarbonate, vinyl chloride, and rubber. 3. An object to be polished is placed in a plurality of holding holes provided in a polishing carrier, and the upper and lower platens are rotated while the object to be polished is sandwiched between a lower platen and an upper platen. In a polishing method of lapping and / or polishing the main surface and mirror-polishing the main surface of the object to be polished,
A polishing method, wherein at least an inner peripheral portion of the holding hole that is in contact with the object to be polished is made of a material softer than a polishing pad used in a polishing step. 4. The material has a hardness of 100 or less (Ask
4. The polishing method according to claim 3, wherein er-C). 5. The polishing method according to claim 3, wherein the object to be polished is made of glass or silicon. 6. An information recording medium substrate is inserted into a plurality of polished body holding holes provided in a polishing carrier, and the upper and lower platens are sandwiched between the lower and upper platens while holding the information recording medium substrate. Rotating the main surface of the information recording medium substrate by lapping and / or polishing the main surface of the information recording medium substrate, and polishing the main surface of the information recording medium substrate to a mirror finish. A method for manufacturing a substrate for an information recording medium, wherein an inner peripheral portion of the polished body holding hole in contact with the substrate for an information recording medium is formed of a material softer than a polishing pad used in a polishing step. 7. After polishing an end face of the information recording medium substrate, the information recording medium substrate is put into a plurality of holding holes provided in a polishing carrier, and the object to be polished is polished by a lower platen and an upper platen. A method of manufacturing a substrate for an information recording medium, comprising: a polishing step of polishing the information recording medium substrate by lapping and / or polishing the main surface of the information recording medium substrate while rotating the upper and lower platens in a sandwiched state. An information recording medium substrate, wherein at least an inner peripheral portion of the polished body holding hole that is in contact with the information recording medium substrate is formed of a material softer than a polishing pad used in a polishing step. Production method.