JPH08197434A - Pad for grinding - Google Patents

Abstract

PURPOSE: To provide a durable pad for grinding by embossing recessed grooves formed on the surface of a grinding layer and thereby reducing dust produced from the ends of the grooves. CONSTITUTION: A pad for grinding comprises porous forming resin for grinding layer 15 containing the material to be ground and has a desired pattern on the surface of the grinding layer by embossing the recessed grooves 18 with hot press, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing pad used in a polishing apparatus for a work piece, which requires extremely small surface roughness.

[0002]

2. Description of the Related Art Conventional CDs (compact discs) and LDs
As a polishing pad for a polishing apparatus for polishing the surface of a glass master used for manufacturing (laser disk), for example, there is a polishing pad having a structure as shown in FIGS. 6 (a), (b) and (c). . That is, in (a) and (b), a large number of relatively shallow cutting grooves 26 are provided by mechanical grinding on the surface of a porous resin such as urethane foam. The cutting groove 26 guides the liquid abrasive used together during polishing between the pad and the object to be processed and spreads it evenly over the surface of the object to be processed, but it is machined. The cutting grooves 26 tend to have burrs 27 on their end faces, and these burrs 27 fall off during polishing and become dust, which adheres to the surface of the workpiece or adheres to the inside of the polishing chamber. It has a drawback that it adheres to the brush used in the dressing process of the pad before and after the polishing process and significantly reduces the polishing and cleaning effects. The amount of dust generated increases as the number of times of use increases, but when the amount of dust becomes remarkable, it becomes the utilization limit. Also (c)
There are some pads that do not have any concave grooves on the surface, as shown in, but the disadvantage is that the polishing agent cannot be evenly distributed between the pad and the workpiece during polishing, so uniform polishing cannot be performed. .

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a polishing pad having a large durability by minimizing the generation of dust from the pad surface.

[0004]

In order to solve such a problem, in the present invention, a groove is formed on the surface of a polishing pad by embossing by means such as a heating press.

[0005]

Since the concave groove is formed on the polishing pad by embossing with a hot press or the like, a polishing pad with extremely few burrs from the end surface of the concave groove can be realized.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and function of the polishing pad of the present invention will be described below with reference to FIGS.
An example applied to the polishing of a glass master used for manufacturing disks such as the above will be described.

First, FIG. 1 is a side view showing an entire polishing apparatus for polishing the surface of a master of a disk such as a CD in which the polishing pad of the present invention is used. A rotary shaft 3 having a turntable 2 fixed thereto is provided on the upper portion of the base 1. The surface of the turntable 2 is provided with an opening for vacuum adsorption and a pore connected to it inside. Also the base 1
In order to drive the rotary shaft 3, a rotary drive mechanism in which the electric motor M1 is connected to the rotary shaft 3 via a gear or the like is provided in the lower part of the. The arm 4 is attached to a rotary shaft 5 so as to be freely rotatable on the turntable 2. Further, a pad unit mounting shaft 6 is provided at the tip of the arm 4, and a pad unit 7 to be described later is mounted thereto. There is. Further, at the tip of the arm 4, a polishing agent supply nozzle 8 having a tip extended to the side surface of the pad unit 7 and a water injection nozzle 9 for cleaning.
Is attached. The pad unit mounting shaft 6 is rotationally driven by an electric motor M2 provided above the rotary shaft 6 via a timing belt or the like provided in the arm 4. Further, a rotating shaft 5 is driven by an electric motor M3 via a gear at the lower part of the base 1, and a lower end of the rotating shaft 5 such as an air cylinder for moving it up and down. A dynamic drive mechanism B1 is provided.

Further, a pad cleaning unit 12 having a fixed cleaning brush 10 and a water injection nozzle 11 for supplying water for cleaning is arranged at an appropriate position within a reach of the arm 4 on the base 1. When polishing the glass master disk 13 as a workpiece, the glass master disk 13 is placed on the turntable 2 and fixed by a vacuum suction mechanism. And turntable 2
While rotating the pad unit 7 while pressing the glass master 13 with an appropriate pressure while discharging the abrasive composed of a mixed liquid in which a slurry such as cerium oxide is mixed as an abrasive from the abrasive supply nozzle 8. And the pad is rotated at a suitable speed in the direction across the glass master. When the polishing process is completed, the pad unit 7 is released upward, pure water is discharged from the water injection nozzle 9, and the polishing agent on the glass master is washed away. When the polishing of several tens of sheets is completed in this way, the polishing pad is worn out and fluffed. Therefore, the arm 10 is rotated to bring the pad unit 7 into contact with the brush 10 of the pad cleaning unit 12, and while rotating, Water is injected from the water injection nozzle 11 for cleaning.

2 (a) is a side sectional view of the polishing pad of the present invention, and FIG. 2 (b) is a plan view of the same. The polishing pad 14 of the present invention has a polishing layer 15 in direct contact with a workpiece and its polishing layer 15. The base layer 16 is formed thereon, and the adhesive layer 17 is further laminated thereon. As a constituent material of the polishing layer 15, a polyurethane resin-based open-cell type foamed resin is suitable. Although urethane foam is well known as a typical material of this kind, it is most suitable for the polishing layer of a polishing pad for polishing by using a liquid abrasive in combination because it has good water absorption and elasticity. As a constituent material of the base layer 16, a non-woven fabric having appropriate elasticity is preferable. The adhesive layer 17 is suitable because it can be easily attached by using a double-sided adhesive tape.

The concave groove 18 provided on the surface of the polishing layer 15 can be manufactured by using, for example, a mold 19 shown in FIG.
The mold 19 is composed of an upper mold 20 and a lower mold 21. The upper mold 20 is provided with a ridge 22a for forming a concave groove in a desired pattern. In addition, the lower die 21 has a ridge 22 of the upper die 20.
A concave line 22b that matches a is provided, and guide holes 23a and 23b for guiding the lower mold 21 are provided near the outer periphery thereof. The ridge 22 has a top width W1 of 0.10.
.About.0.25 mm and height H1 of about 2.0 to 2.5 mm. Further, guide pins 24a and 24b fitted in the guide holes 23a and 23b of the upper mold 20 are provided near the outer periphery of the lower mold 21. Then, this mold is attached to a compression press (not shown), and the polishing layer surface of the pad is projected between the upper and lower molds by a ridge 23.
The mold is heated to a temperature of about 95 to 110 ° C. and pressed. The pressurization condition is a surface pressure of 290 to 300k.
The holding time was g / cm ² and the holding time was 2 to 5 seconds. Compared with the case of conventional cutting, the concave groove 18 pressed under such conditions has only the texture of the end surface of the groove, so that it has no burr and is physically stable, so that dust is not generated. It can be significantly reduced. Further, during polishing, the shape can be stably maintained even when immersed in a liquid polishing agent.

FIG. 2 shows a state in which the pad 14 thus completed is attached to a disk-shaped pad head 25 to form a pad unit 7, which is attached to the pad unit attachment shaft 6 of the polishing apparatus.

The interval between the grooves formed on the surface of the polishing layer 15 of the pad is about 5 mm to 10 mm, and the patterns formed by the grooves are the lattice stripes in FIG. 2 (b), FIG. 5 (a),
(B) a pattern with diagonal lines added to the checkered pattern, (c) a honeycomb,
It is desirable to have regularity such as (d) small circles and (e) concentric circles.

In the embodiments of the present invention, the shape of the polishing pad has been described as a disc shape, but it is needless to say that the present invention is not limited to the disc shape and can be applied to polishing pads having other shapes.

[0014]

As is apparent from the above description, according to the present invention, the embossed concave grooves are formed on the surface of the polishing layer of the polishing pad by a hot press or the like in a regular pattern. It is possible to obtain a polishing pad that is less likely to occur and has a better introduction of abrasives used during polishing, and is more durable than before. When polishing is performed using this pad, dust on the polishing surface of the work piece It is possible to reduce the scratches caused by, and as a result, CD, L with less dropout
A recording disk such as D can be provided.

[Brief description of drawings]

FIG. 1 is a side view of a polishing apparatus using a polishing pad of the present invention.

FIG. 2A is a side sectional view of the polishing pad of the present invention,
(B) is the same top view.

FIG. 3 is a side view showing a state in which the polishing pad of the present invention is attached to a polishing apparatus.

FIG. 4 is a die side view of a press for manufacturing the polishing pad of the present invention.

5 (a) to 5 (e) are examples of patterns of grooves provided on the surface of the polishing layer of the polishing pad of the present invention.

FIG. 6A is a side sectional view of a conventional polishing pad,
(B) is the same top view.

[Explanation of symbols]

 1 Base 2 Turntable 3 Rotating Shaft 4 Arm 5 Rotating Shaft 6 Pad Unit Mounting Shaft 7 Pad Unit 8 Abrasive Material Supply Nozzle 9 Water Injection Nozzle 10 Brush 11 Water Injection Nozzle 12 Pad Cleaning Unit 13 Glass Master 14 Pad 15 Polishing Layer 16 Base Layer 17 Adhesive layer 18 Recessed groove 19 Mold 20 Upper die 21 Lower die 22a Convex strip 22b Recessed strip 23a, 23b Guide hole 24a, 24b Guide pin 25 Pad head 26 Cutting recessed groove 27 Burr

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[Procedure amendment]

[Submission date] April 17, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

FIG. 1 is a side view of a polishing apparatus using a polishing pad of the present invention.

FIG. 2A is a side sectional view of the polishing pad of the present invention,
(B) is the same top view.

FIG. 3 is a side view showing a state in which the polishing pad of the present invention is attached to a polishing apparatus.

FIG. 4 is a die side view of a press for manufacturing the polishing pad of the present invention.

5 (a) to 5 (e) are examples of patterns of grooves provided on the surface of the polishing layer of the polishing pad of the present invention.

FIG. 6A is a side sectional view of a conventional polishing pad,
(B) is the same plan view, (c) is a plan view of another conventional polishing pad.

[Explanation of symbols] 1 base 2 turntable 3 rotating shaft 4 arm 5 rotating shaft 6 pad unit mounting shaft 7 pad unit 8 abrasive material supply nozzle 9 water injection nozzle 10 brush 11 water injection nozzle 12 pad cleaning unit 13 glass master disk 14 pad 15 polishing layer 16 base layer 17 adhesive layer 18 concave groove 19 mold 20 upper mold 21 lower mold 22a convex stripe 22b concave stripe 23a, 23b guide hole 24a, 24b guide pin 25 pad head 26 cutting concave groove 27 burr

Claims (5)

[Claims] 1. A polishing pad having a large number of recessed grooves formed by embossing on the surface of a polishing layer that is in contact with a workpiece. 2. The polishing pad according to claim 1, wherein the concave groove forms a regular pattern on the surface of the polishing layer. 3. The polishing pad according to claim 1, wherein the pattern is a checkered pattern, a honeycomb pattern, or repeating small circles or concentric circles. 4. The polishing pad according to claim 1, wherein the polishing layer comprises an open-cell foam resin. 5. The polishing pad according to claim 1, wherein a base layer made of a synthetic resin having elasticity is provided on the back side of the polishing layer, and an adhesive layer is provided on the back side of the base layer.