JP7181040B2 - Polishing pad, method for producing same, and method for producing abrasive product - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polishing pad, a method for manufacturing the same, and a method for manufacturing a polished article.

A wafer such as a silicon single crystal is formed with a small notch (notch portion) formed at the edge portion of the outermost periphery of the wafer in order to indicate its direction. The surface of the wafer is subjected to chemical mechanical polishing or the like using a polishing slurry and a polishing pad, and the notch portion is also subjected to polishing for the purpose of preventing chipping and entrainment of dust.

As a polishing pad used for polishing such a notch portion, for example, it is intended to provide a polishing pad suitable for polishing the notch portion and its peripheral portion and having a long product life. A polishing pad made by impregnating a material with a resin has a three-layer structure in which the inner layer portion and the outer layer portion have different densities (see, for example, Patent Document 1), and a base material impregnated with a resin. A known polishing pad has a porosity distribution that increases from the outer side in the thickness direction of the base material to the center side in the thickness direction (see, for example, Patent Document 2). .)

JP 2010-157619 A JP 2011-009584 A

However, since the polishing pads disclosed in Patent Documents 1 and 2 have different densities and hardness depending on the location, the amount of slurry held and the contact with the workpiece are not uniform, resulting in variations in the polishing state and scratches. there is a risk of In addition, since the polishing pad for polishing the notch portion of the work is brought into contact with the main surface of the work and the main surface of the polishing pad so that the main surface of the work and the polishing pad are substantially perpendicular to each other during the polishing process, there is a problem that the polishing pad wears rapidly and its life is shortened. be.

In order to solve such problems, it is conceivable to increase the hardness of the polishing pad. It has been found that a new problem arises in that the time (hereinafter, also referred to as "rise time") required for exhibiting the polishing performance (the notch portion becomes smooth) is prolonged. In particular, if the rise time is prolonged, the number of dummy workpieces used to bring the polishing pad into a state where it exhibits uniform polishing performance (hereinafter also referred to as the "startup state") will increase. problem arises.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polishing pad with a reduced rise time, a method for manufacturing the same, and a method for manufacturing a polished product using the polishing pad. .

The present inventors have made intensive studies to solve the above problems. As a result, the inventors have found that the above-mentioned problems can be solved by making the polished portion have a predetermined surface state, and have completed the present invention.

[1]
A doughnut-shaped disk-shaped polishing pad made of a resin-impregnated nonwoven fabric containing a nonwoven fabric and a resin impregnated in the nonwoven fabric,
having a polishing section on the outer periphery of the disk for polishing the notch formed on the outer peripheral edge of the work;
The arithmetic mean height of the surface of the polishing portion that contacts the notch portion is 55 to 100 μm.
polishing pad.
[2]
The arithmetic mean curvature of the crest point of the surface of the polishing portion in contact with the notch portion is 475 to 700 mm ⁻¹ ,
The polishing pad according to claim 1.
[3]
The resin-impregnated nonwoven fabric has a Shore A hardness of 70 to 90°.
The polishing pad according to claim 1 or 2.
[4]
The resin-impregnated nonwoven fabric has a density of 0.30 to 0.50 g/cm ³ ,
The polishing pad according to any one of claims 1-3.
[5]
The resin comprises a polyurethane-based resin,
The polishing pad according to any one of claims 1-4.
[6]
An impregnation step of impregnating a nonwoven fabric with a resin solution and performing wet coagulation;
a polishing portion forming step of forming a polishing portion for polishing the notch portion formed in the outer peripheral edge of the work;
In the polishing portion forming step, the arithmetic mean height of the surface of the polishing portion in contact with the notch portion is adjusted to 55 to 100 μm;
A method for manufacturing a polishing pad.
[7]
Using the polishing pad according to any one of claims 1 to 5, a polishing step of polishing a notch formed in the outer peripheral edge of the work,
A method for producing an abrasive product.

According to the present invention, it is possible to provide a polishing pad with a reduced rising time, a method for manufacturing the same, and a method for manufacturing a polished product using the polishing pad.

It is the schematic which shows an example of the usage method of the polishing pad of this embodiment. FIG. 4 is a diagram showing a method of collecting samples used for measuring the arithmetic mean height and the arithmetic mean curve of the summit point;

Hereinafter, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail, but the present invention is not limited to this, and various modifications are possible without departing from the gist thereof. is.

[Polishing pad]
The polishing pad of the present embodiment is a doughnut-shaped disk-shaped polishing pad made of resin-impregnated nonwoven fabric containing nonwoven fabric and resin impregnated in the nonwoven fabric, and a notch formed on the outer peripheral edge of a work (object to be polished). A polishing portion for polishing a portion is provided on the outer circumference of the disk, and the arithmetic mean height of the surface of the polishing portion that contacts the notch portion is 55 to 100 μm. The “doughnut-shaped disc shape”, which is the shape of the polishing pad, means a shape having a hole penetrating in the thickness direction of the disc shape near the center of the substantially disc shape.

FIG. 1 shows an example of how to use the polishing pad of this embodiment. The polishing pad of the present embodiment is a doughnut-shaped disk-shaped polishing pad having a polishing portion on the outer periphery of the disk, and the polishing portion polishes a notch formed on the outer peripheral edge of the workpiece. Specifically, the notch portion is polished by the polishing portion by rotating the polishing pad while bringing the polishing portion into contact with the notch portion of the workpiece.

In order for the polishing pad to exhibit a uniform polishing performance (the notch becomes smooth) (in a raised state), the surface of the polishing portion that contacts the notch (hereinafter also referred to as the “contact surface”) is required. ) has a predetermined unevenness is one of the conditions. On the other hand, if the contact surface is too rough, there is concern that the notch may be scratched, resulting in deterioration of quality. Therefore, in the present embodiment, the arithmetic mean height of the surface of the polishing portion that contacts the notch portion is defined within a predetermined range so that such a surface can be formed more efficiently. In addition, the ground contact surface is affected by the direction of processing, and the fluff on the surface may collapse in the direction of processing. can be When measuring the surface roughness of such a contact surface using a contact surface roughness meter, the surface roughness Ra measured from the processing direction and the surface roughness Ra measured from the opposite direction to the processing direction , and the surface roughness (Ra) in the direction perpendicular to the processing direction have different values. Moreover, since the surface roughness (line roughness) of the contact surface as described above is highly dependent on the measurement direction, the values obtained differ depending on the measurement direction even when a non-contact type measuring device is used. On the other hand, the arithmetic mean height can be evaluated by using a non-contact type device and by evaluating the uneven state without being affected by the direction.

From the above point of view, the arithmetic mean height (Sa) of the surface of the polishing portion in contact with the notch portion of the present embodiment is 55 to 100 μm, preferably 60 to 95 μm, more preferably 65 to 90 μm. is. When the arithmetic mean height is 55 μm or more, the rising time is shortened, the polishing efficiency is improved, and the number of dummy works can be reduced, thereby reducing the manufacturing cost. Further, when the arithmetic mean height is 100 μm or less, the quality of the resulting polished object is further improved. The arithmetic mean height of a surface (Sa) is a parameter obtained by extending the arithmetic mean height of a line (Ra) to a surface, and is the average of the absolute values of the height differences of each point with respect to the average surface of a certain surface. represents The arithmetic mean height (Sa) can be determined according to ISO25178, and specifically can be determined by the method described in Examples. Methods for adjusting the arithmetic mean height within the above range include, for example, a method of grinding the contact surface with sandpaper, and a method of adjusting the roughness of the sandpaper used.

From the same point of view as above, the arithmetic mean curvature of the crest point of the surface of the polishing portion in contact with the notch portion of the present embodiment may be further considered. The arithmetic mean curvature of peaks is preferably 475 to 700 mm ^-1 , more preferably 485 to 675 mm ^-1 , still more preferably 500 to 650 mm ^-1 . When the arithmetic mean curvature of the crest is 475 mm ^-1 or more, the rise time is shortened, the polishing efficiency is improved, and the number of dummy workpieces can be reduced, which tends to reduce the manufacturing cost. . Further, when the arithmetic mean curvature of the crest point is 700 mm ^-1 or less, the quality of the resulting polished object tends to be further improved. Arithmetic mean curvature of peaks (Spc) is a parameter that represents the average principal curvature of peaks on the surface. indicates that the point of contact with the workpiece is sharp. The arithmetic mean curve (Spc) of peaks can be obtained in conformity with ISO25178, and specifically can be obtained by the method described in Examples. Examples of the method for adjusting the arithmetic mean curve of the crest within the above range include a method of grinding the contact surface with sandpaper, and a method of adjusting the roughness of the sandpaper used.

[Resin impregnated nonwoven fabric]
The polishing pad of this embodiment is made of a resin-impregnated nonwoven fabric containing a nonwoven fabric and a resin impregnated in the nonwoven fabric. Hereinafter, aspects of the resin-impregnated nonwoven fabric constituting the polishing pad will be described in detail.

(non-woven fabric)
The fibers constituting the nonwoven fabric are not particularly limited, but examples include polyamide fibers, polyester fibers such as polyethylene terephthalate, polyolefin fibers such as polypropylene and polyethylene, and synthetic fibers such as acrylic fibers such as (meth)acrylate. include natural fibers such as cotton and linen; The fibers constituting the nonwoven fabric may be used singly or in combination of two or more. Also, nonwoven fabrics made of different fibers may be layered and used. The method for entangling the fibers when obtaining the woven fabric is not particularly limited, and may be, for example, needle punching or hydroentangling.

The fineness of fibers constituting the nonwoven fabric is preferably 0.1 to 10 dtex, more preferably 1.1 to 7.8 dtex, still more preferably 2.2 to 5.6 dtex. When the fineness is within the above range, the occurrence of scratches is reduced, and the arithmetic mean height and the arithmetic mean curvature of the peak point tend to be easily adjusted within the above range.

The average fiber length of fibers constituting the nonwoven fabric is preferably 20 to 80 mm, more preferably 28 to 70 mm, still more preferably 32 to 55 mm. When the fiber length is within the above range, the occurrence of scratches is reduced, and the arithmetic mean height and the arithmetic mean curvature of the peak point tend to be easily adjusted to the above range.

The thickness of the nonwoven fabric is preferably 2-7 mm, more preferably 3-6 mm, and even more preferably 4-5 mm. The thickness of the nonwoven fabric can be appropriately adjusted to suit the notches to be polished.

(resin)
The resin with which the nonwoven fabric is impregnated is not particularly limited, but resins that can be impregnated into the nonwoven fabric by so-called wet impregnation (hereinafter also referred to as "wet resin") can be used. Examples of such wet resins include, but are not limited to, polyurethane resins such as polyurethane and polyurethane polyurea; acrylic resins such as polyacrylate and polyacrylonitrile; vinyl chlorides such as polyvinyl chloride, polyvinyl acetate, and polyvinylidene fluoride. polysulfone-based resins such as polysulfone and polyethersulfone; acylated cellulose-based resins such as acetylated cellulose and butyrylated cellulose; polyamide-based resins; and polystyrene-based resins. Among these, polyurethane-based resins are preferred. By using such a resin, the rising time is shortened, the polishing efficiency is improved, and the number of dummy works can be reduced, which tends to reduce the manufacturing cost.

Examples of polyurethane resins include, but are not limited to, polyester-based polyurethane resins, polyether-based polyurethane resins, and polycarbonate-based polyurethane resins.

The amount of the resin impregnated into the nonwoven fabric is preferably 0.8 to 2 parts by mass, more preferably 0.9 to 1.7 parts by mass, and still more preferably 1 to 1 part by mass with respect to 1 part by mass of the nonwoven fabric. .5 parts by mass. When the amount of the resin impregnated into the nonwoven fabric is within the above range, the hardness of the polishing pad tends to be further improved, which tends to further improve the life of the polishing pad. Also, physical properties such as hardness of the polishing pad can be adjusted by adjusting the proportion of the nonwoven fabric and the resin. In addition, since it is possible to adjust the ease with which the fibers are exposed from the resin, it tends to be easier to adjust the arithmetic mean height and the arithmetic mean curvature of the summit point within the above ranges.

The Shore A hardness of the resin-impregnated nonwoven fabric is preferably 65 to 95°, more preferably 70 to 90°, still more preferably 75 to 85°. When the Shore A hardness is 65° or more, the life of the polishing pad tends to be further improved. Moreover, since the Shore A hardness is 95° or less, the occurrence of scratches tends to be suppressed, and the quality of the resulting polished object tends to be further improved. The Shore A hardness can be measured by the method described in Examples. Also, the Shore A hardness can be adjusted by, for example, the type and adhesion amount of the resin used.

The density of the resin-impregnated nonwoven fabric is preferably 0.30 to 0.50 g/cm ³ , more preferably 0.35 to 0.50 g/cm ³ , still more preferably 0.40 to 0.45 g/cm 3 is ³ . A density of 0.30 g/cm ³ or more tends to further improve the life of the polishing pad. Further, when the density is 0.50 g/cm ³ or less, the occurrence of scratches tends to be suppressed, and the quality of the resulting polished object tends to be further improved. The density can be measured by the method described in Examples. Also, the density can be adjusted by, for example, the impregnation amount of the resin.

The compressibility of the resin-impregnated nonwoven fabric is preferably 0.5 to 7%, more preferably 0.5 to 5%, still more preferably 0.5 to 3%. When the compressibility is within the above range, the adhesion to the notch portion is improved, and deformation of the polishing pad is minimized in the polishing process in which the main surface of the workpiece and the main surface of the polishing pad are brought into contact so as to be substantially perpendicular to each other. tend to be more restrained. The compressibility can be measured by the method described in Examples. Also, the compressibility can be adjusted by adjusting the density.

The compression elastic modulus of the resin-impregnated nonwoven fabric is preferably 85-98%, more preferably 90-98%, still more preferably 92-96%. When the compression elastic modulus is within the above range, the adhesion to the notch portion is improved, and deformation of the polishing pad is prevented in the polishing process in which the main surface of the workpiece and the main surface of the polishing pad are brought into contact so as to be substantially perpendicular to each other. tend to be more suppressed. The compression modulus can be measured by the method described in Examples. Also, the compression modulus can be adjusted depending on the type of resin used.

The thickness of the polishing pad of this embodiment is preferably 2 to 7 mm, more preferably 3 to 6 mm, still more preferably 4 to 5 mm. The thickness of the polishing pad can be appropriately adjusted to suit the notches to be polished.

[Method for producing polishing pad]
The manufacturing method of the polishing pad of the present embodiment includes an impregnation step of impregnating a nonwoven fabric with a resin solution and performing wet coagulation, and a polishing portion forming a polishing portion for polishing a notch portion formed on the outer peripheral edge of a work. In the polishing portion forming step, the arithmetic average height of the surface of the polishing portion that contacts the notch portion is adjusted to 55 to 100 μm.

[Impregnation process]
The impregnation step is a step of impregnating a nonwoven fabric with a resin solution and performing wet coagulation. Wet coagulation is a method of solidifying and regenerating a resin by immersing a resin solution in a coagulating liquid that is a poor solvent for the resin. When wet coagulation is used after impregnating a nonwoven fabric with a resin solution as in the present embodiment, in the coagulation liquid, the solvent of the resin solution and the coagulation liquid are replaced on the surface of the resin solution adhering to the fibers of the nonwoven fabric. progresses, whereby the resin is coagulated and reproduced on the surface of the fiber.

The resin solution contains a resin and a solvent, and if necessary, may contain other additives. As the resin, those mentioned as the wet resin can be used. As the solvent, a solvent that can dissolve the wet resin and is miscible with the coagulation liquid can be used. Examples of such solvents include, but are not limited to, N,N-dimethylformamide, N,N-dimethylacetamide, methylethylketone and dimethylsulfoxide.

As a specific wet coagulation method, for example, after the nonwoven fabric is sufficiently immersed in the resin solution, the excess resin solution is squeezed off from the nonwoven fabric using a mangle roller or the like to adjust the amount of resin adhesion, and then, By immersing the nonwoven fabric impregnated with the resin solution in a poor solvent (coagulating liquid) for the resin, the wet resin is coagulated and recycled to obtain a resin-impregnated nonwoven fabric. Examples of the coagulation liquid include water, and if necessary, organic solvents such as polar solvents may be included.

The obtained resin-impregnated nonwoven fabric is washed in a washing liquid such as water to remove solvents such as DMF remaining in the nonwoven fabric. It may be subjected to a drying process to make it dry.

[Polishing part forming process]
The polishing portion forming step is a step of forming a polishing portion for polishing the notch portion formed in the outer peripheral edge of the workpiece. The thickness is adjusted to be 55-100 μm. Specifically, after the resin-impregnated nonwoven fabric that has undergone the drying step is formed into a doughnut-shaped disc, a polishing section is formed on the outer circumference of the disk for polishing the notch formed on the outer peripheral edge of the work. Examples of methods for forming the polished portion include cutting and polishing. After that, the arithmetic average height of the surface of the polishing portion that contacts the notch portion is adjusted to 55 to 100 μm. The adjustment method is not particularly limited, but includes, for example, a method of grinding the surface of the polishing portion with sandpaper or the like.

[Method for producing polished product]
The method for manufacturing a polished product according to the present embodiment includes a polishing step of polishing the notch formed in the outer peripheral edge of the workpiece using the polishing pad. The work is not particularly limited as long as it has a notch. Further, as a polishing method, as shown in FIG. 1, there is a method in which the main surface of the workpiece and the main surface of the polishing pad are brought into contact so as to be substantially perpendicular to each other. In addition to the above-described polishing process, the method for manufacturing a polished product according to the present embodiment includes the above-described polishing pad or another polishing pad having the main surface thereof as a contact surface, and using the polishing pad to polish the main surface of the workpiece. It may have another polishing step for polishing.

A slurry may be used in the polishing step. Components contained in the slurry include, for example, an oxidizing agent, a solvent, and polishing particles (abrasive grains) used in chemical mechanical polishing. Examples of the oxidizing agent include, but are not particularly limited to, hydrogen peroxide. Solvents include, for example, water and organic solvents.

Moreover, the slurry may contain other additives as needed. Examples of such additives include nonionic surfactants, anionic surfactants, carboxylic acid esters, carboxylic acid amides and carboxylic acids.

Hereinafter, the present invention will be described more specifically using examples and comparative examples. The present invention is by no means limited by the following examples.

[Method of measuring arithmetic mean height and arithmetic mean curve of summit point]
As shown in FIG. 2, a sample (about 1 mm thick x about 3 mm wide x about 10 mm long) including a contact surface (measurement surface) is cut out from the outer periphery of a polishing pad for polishing notches, and is used as a measurement sample. did. Note that the size of the measurement sample is not particularly limited as long as it is a size suitable for measuring the arithmetic mean height and the arithmetic mean curve of the summit point. Also, the measurement is performed on the measurement surface of the polishing pad excluding the edge portion (corner portion of the outer peripheral tip).

The arithmetic mean height and the arithmetic mean curvature of the peak point on the contact surface (measurement surface) of the obtained measurement sample were measured using a laser microscope VK-X1000 (model name) manufactured by KEYENCE under the following measurement conditions. .
(Measurement condition)
Lens: X5
Measurement area: 2058.635 μm × 2745.741 μm,
Measurement mode: Focus variation Light intensity: 92
HDR: Not used Illumination: Coaxial epi-illumination + ring illumination used Measurement size: Standard Measurement pitch: 12 μm
Analysis software: KEYENCE multi-file analysis application Image processing: None Filter: Gaussian filter used,
Low-pass filter: None High-pass filter: None Shape correction: None End effect correction: ON
Measurement area: (X, Y) = (121, 6) to (867, 754) rectangular area designation

[Shore A hardness]
Measure the Shore A hardness of the polishing pad from the depth of indentation after 30 seconds of pressing the indentor (probe) against the test piece surface (main surface) of a polishing pad with a thickness of 4.5 mm or more via a spring. did. A durometer type A was used as a measuring device. This was repeated three times, and the Shore A hardness was obtained from the arithmetic mean. Specifically, the polishing pad was cut into a size of 10 cm×10 cm and used as a test piece. If it is difficult to obtain a sample piece of 10 cm×10 cm due to the size of the polishing pad, a sample piece of a size that can be collected may be used for measurement in the same manner as the above method.

[Compression ratio]
The compressibility of the polishing pad was measured according to Japanese Industrial Standards (JIS L 1021) using a Shopper-type thickness gauge (pressure surface: circular with a diameter of 1 cm). Specifically, the thickness t ₀ was measured after pressing for 30 seconds with the initial load, and then the thickness t ₁ after standing under the final pressure for 5 minutes was measured. From these, the compressibility was calculated by the following formula. At this time, the initial load was 100 g/cm ² and the final load was 1120 g/cm ² .
Compression ratio (%)=(t ₀ -t ₁ )/t ₀ ×100

[Compression modulus]
The compression elastic modulus of the polishing pad was measured in accordance with Japanese Industrial Standards (JIS L 1021) using a Shopper-type thickness gauge (pressure surface: circular with a diameter of 1 cm). Specifically, the thickness t ₀ after pressing for 30 seconds under the initial load was measured, and then the thickness t ₁ after standing for 5 minutes under the final load was measured. The thickness t ₀ ' was measured after all the loads were removed and the sample was allowed to stand for 1 minute, and then pressurized again with the initial load for 30 seconds. From these, the compression elastic modulus was calculated by the following formula. At this time, the initial load was 100 g/cm ² and the final load was 1120 g/cm ² .
Compressive modulus (%) = (t ₀ '-t ₁ )/(t ₀ -t ₁ ) x 100

〔thickness〕
The thickness of the polishing pad was measured according to Japanese Industrial Standards (JIS K 6505) using a Shopper-type thickness gauge (pressure surface: circular with a diameter of 1 cm). Specifically, three sample pieces of 10 cm × 10 cm were prepared by cutting out a polishing pad, and after each sample piece was set at a predetermined position of a thickness measuring instrument, a pressure surface was applied with a load of 480 g/cm ² . It was placed on the surface of the sample piece, and the thickness was measured after 5 seconds. The thickness of each sample piece was measured at 5 points, the arithmetic average was calculated, and the arithmetic average of the 3 sample pieces was calculated. If it is difficult to obtain a 10 cm x 10 cm sample piece due to the size of the polishing pad, the thickness of the polishing pad may be determined by measuring the thickness at 15 points in the polishing pad and calculating the arithmetic average.

〔density〕
The density of the polishing pad was measured according to Japanese Industrial Standards (JIS K 6505). Specifically, prepare a sample piece similar to that used in the thickness measurement, measure the mass with an automatic balance, calculate the density by the following formula, and obtain the arithmetic mean of the three sample pieces. was taken as the density of the polishing pad. If it is difficult to obtain a sample piece of 10 cm × 10 cm due to the size of the polishing pad, prepare three sample pieces of a size that can be collected, calculate the density from the mass and volume of the sample, and An arithmetic mean may be obtained as the density of the polishing pad.
Density (g/cm ³ )=mass (g)/(10 (cm)×10 (cm)×thickness of sample piece (cm))

[Rise evaluation]
Assuming that the start-up state is the state where there are no scratches from the start of use and uniform polishing can be performed, the start-up time is the ratio of the time required for start-up of the conventional product (Comparative Example 1) to 100. evaluated.

[Example 1]
A nonwoven fabric made of polyethylene terephthalate fibers (fineness 3.3 dtex, average fiber length 51 mm) was immersed in a resin solution containing polyurethane resin (100% modulus 12 Mps) and N,N-dimethylformamide. After the immersion, excess resin solution was squeezed out using a mangle roller capable of applying pressure between a pair of rollers, and the nonwoven fabric was substantially uniformly impregnated with the resin solution. Next, by immersing the fabric in a coagulating liquid consisting of water at room temperature, the resin was coagulated and regenerated to obtain a resin-impregnated nonwoven fabric. In the obtained resin-impregnated nonwoven fabric, the resin content was 1.3 parts by mass with respect to 1 part by mass of the nonwoven fabric.

After that, the obtained resin-impregnated nonwoven fabric was formed into a doughnut-shaped disc, and a polishing section was formed on the outer periphery for polishing the notch formed on the outer peripheral edge of the work. Next, the surface of the polishing portion in contact with the notch portion was ground with sandpaper (#320) to obtain a polishing pad having a thickness of 4.5 mm and a density of 0.43 g/cm ³ .

[Example 2]
A polishing pad was obtained in the same manner as in Example 1, except that sandpaper (#240) was used instead of sandpaper (#320).

[Example 3]
A polishing pad was obtained in the same manner as in Example 1, except that sandpaper (#100) was used instead of sandpaper (#320).

[Comparative Example 1]
A polishing pad was obtained in the same manner as in Example 1, except that sandpaper (#600) was used instead of sandpaper (#320).

Further, when the life of the polishing pads was checked, all the pads had a similar life.

INDUSTRIAL APPLICABILITY The polishing pad of the present invention has industrial applicability as a polishing pad for polishing a notch formed on the outer peripheral edge of a work.

Claims (7)

A doughnut-shaped disk-shaped polishing pad made of a nonwoven fabric made of polyethylene terephthalate fibers and a resin-impregnated nonwoven fabric containing a polyurethane resin impregnated in the nonwoven fabric,
having a polishing section on the outer periphery of the disk for polishing the notch formed on the outer peripheral edge of the work;
The arithmetic mean height of the surface of the polishing portion that contacts the notch portion is 55 to 100 μm.
polishing pad. The arithmetic mean curvature of the crest point of the surface of the polishing portion in contact with the notch portion is 475 to 700 mm ⁻¹ ,
The polishing pad according to claim 1. The resin-impregnated nonwoven fabric has a Shore A hardness of 70 to 90°.
The polishing pad according to claim 1 or 2. The resin-impregnated nonwoven fabric has a density of 0.30 to 0.50 g/cm ³ ,
The polishing pad according to any one of claims 1-3. The resin comprises a polyurethane-based resin,
The polishing pad according to any one of claims 1-4. An impregnation step of impregnating a nonwoven fabric made of polyethylene terephthalate fibers with a resin solution containing a polyurethane resin and performing wet coagulation;
a polishing portion forming step of forming a polishing portion for polishing the notch portion formed in the outer peripheral edge of the work;
In the polishing portion forming step, the arithmetic mean height of the surface of the polishing portion in contact with the notch portion is adjusted to 55 to 100 μm;
A method for manufacturing a polishing pad. Using the polishing pad according to any one of claims 1 to 5, a polishing step of polishing a notch formed in the outer peripheral edge of the work,
A method for producing an abrasive product.

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