JPH0985605A - Polishing tool - Google Patents

Abstract

(57) Abstract: Even if a polishing tool is moved relative to a workpiece L, a contact position between a polishing pad and the workpiece does not deviate from a target position. SOLUTION: A substantially hemispherical elastic member 12 mounted on a support plate 11 centering on an extension line of a rotating shaft 15,
A polishing pad 14 that covers the elastic member 12 and an elastic member frame 14 that is open in the vicinity of the extension line of the rotating shaft 15 and covers the side circumference of the elastic member 12 around the rotating shaft 15 are provided. Even if the polishing tool moves relative to the work piece L in the X direction, the elastic member frame 14 is provided, so that the elastic member 12 is hardly elastically deformed in the opposite direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing tool for polishing optical elements, semiconductors, ceramics, etc.
The present invention relates to a polishing tool constituted by covering an elastic member with a polishing pad.

[0002]

2. Description of the Related Art As a conventional polishing tool, for example, there is one shown in Japanese Utility Model Laid-Open No. 2-11463. As shown in FIG. 4, this polishing tool has an elastic member 2 mounted on a support plate 1 and a polishing pad 3 covering the elastic member 2. As shown in FIG. 5, this polishing tool is rotated while being pressed against the workpiece L to polish the workpiece L.

[0003]

However, in such a conventional technique, the elastic member 2 is interposed between the support plate 1 and the polishing pad 3 so that a local pressure is not applied to the work piece L. Therefore, as shown in FIG. 5, when the polishing tool is relatively moved with respect to the workpiece L, a frictional force in the direction opposite to the moving direction X acts on the polishing pad 3 and the elastic member 2 acts on the rotating shaft. On the other hand, there is a problem that elastic deformation also occurs in the direction perpendicular to the contact position between the polishing pad 3 and the workpiece L from the target position, and delicate polishing cannot be performed. More specifically, for example, when there is an inflection point in the target shape of the workpiece L, there is a problem that the position of this inflection point may deviate from the target position.

Therefore, a method is conceivable in which the thickness of the elastic member 2 in the pressing direction Z of the polishing tool is reduced in order to reduce the amount of deformation of the elastic member 2 in the moving direction X of the polishing tool.
With this method, the amount of elastic deformation of the polishing tool in the pressing direction Z becomes small, and the initial purpose of preventing local pressure from being applied to the workpiece L cannot be achieved.

The present invention has been made by paying attention to such a conventional problem, and provides a polishing tool capable of performing delicate polishing without applying a local pressure to the workpiece L. The purpose is to

[0006]

A polishing tool for achieving the above object comprises a support plate (11), an elastic member (12) mounted on the support plate (11), and the elastic member (1).
2) a polishing pad (13) covering the elastic member (1) having a direction component perpendicular to the pressing direction (Z) to the workpiece (L).
Strain deformation prevention means (14, 14a) for suppressing the deformation of 2)
Are provided.

Further, another polishing tool for achieving the above object is a support plate (11) attached to a rotating shaft (15) serving as a center of rotation, and a supporting plate centered on an extension line of the rotating shaft (15). A substantially hemispherical elastic member (12) mounted on (11) and a polishing pad (13) covering the elastic member (12) have rigidity, and an opening is formed near the extension line of the rotating shaft (15). Then, the elastic member 12 is centered on the rotary shaft 15.
And elastic member frames (14, 14a) that cover the side circumference of the.

Here, the substantially hemispherical elastic member (12)
It is preferable that the minimum polar radius is smaller than the minimum polar radius in the target shape of the workpiece (L). Further, the elastic member frame (14, 14a) is made up of the elastic member (1
It may be arranged on the outer peripheral side of 2) and on the inner peripheral side of the polishing pad (13) or on the outer peripheral side of the elastic member (12) and the polishing pad (13).

The elastic member (12) may be silicone rubber. Also, the polishing pad (13)
May be a sponge having a plurality of fine pores.
In this case, the average pore diameter of the sponge is 5 μm to 500 μm.
It is desirable that it is m.

In the above, the code in () is
It is a code | symbol of the corresponding part in embodiment of the following polishing tools.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, polishing tools as various embodiments according to the present invention will be described with reference to the drawings.

First, a polishing tool according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, this polishing tool includes a disc-shaped support plate 11 attached to an end portion of a rotary shaft 15 and a rotary shaft 15.
The substantially hemispherical elastic member 12 attached to the support plate 11 centering on the extension line of the elastic member, the elastic member frame 14 covering the side circumference of the elastic member 12, the elastic member 12 and the elastic member frame 14
And a polishing pad 13 for covering the same.

The radius of the hemispherical elastic member 12 is smaller than the minimum radius of curvature of the target shape of the workpiece L.
Here, the elastic member 12 is formed in a hemispherical shape, but may be in a hemispherical shape, for example, as long as it has a substantially hemispherical shape. Even in this case, it is desirable that the elastic member 12 has a minimum radius of curvature smaller than the minimum radius of curvature of the target shape of the workpiece L. The elastic member 12 is made of silicon rubber here. Since the hardness and elastic coefficient of silicon rubber can be adjusted during the molding process, the hardness and elastic coefficient are adjusted so that the required elastic force can be obtained during polishing. The elastic member 1 here
2 has a hardness within the range of JIS-A5 to JIS-A80. Further, although silicon rubber is used as the elastic member 12 here, other materials may be used as the elastic member as long as the desired hardness and elastic coefficient can be obtained.

The polishing pad 13 is made of foamed resin, that is, sponge, specifically, foamed urethane rubber. The polishing pad 13 has a thickness of 2 mm or more,
The average diameter of the foamed pores is 5 μm to 500 μm. The polishing pad 13 may be formed of urethane foam or other foaming resin.

The elastic member frame 14 covers the side peripheral surface of the elastic member 12 between the support plate 11 and the height of about 2/3 at the height of the elastic member 12 in the direction Z in which the rotating shaft 15 extends. ing. As a result, the height from the support plate 11 is about 2 /
The elastic members 12 in the third and subsequent portions are not covered with the elastic member frame 14. In other words, the elastic member frame 14 opens near the extension line of the rotating shaft 15 and covers the side circumference of the elastic member 12 around the rotating shaft 15. The elastic member frame 1
The height of the No. 4 from the support plate 11 in the Z direction is set to about 2/3 of the height before the elastic deformation here, but the present invention is not limited to this, and the elastic member 12 is not limited to the frame 14. It is only necessary to be slightly lower than the expected height of the elastic member 12 when elastically deformed so that the elastic deformation is performed by a predetermined amount without being disturbed. That is, for example, when the height of the elastic member 12 becomes 3/4 of the initial height as a result of elastic deformation, the height may be slightly lower than this, that is, about 3/5.

The support plate 11 and the elastic member frame 14 are made of rigid metal or resin.

Next, regarding the usage of this polishing tool,
This will be described with reference to FIG. This polishing tool rotates about the rotating shaft 15 and moves relative to the workpiece L while applying a load in the direction Z in which the rotating shaft 15 extends,
The work piece (L) is polished. Since a load in the Z direction is applied to the polishing tool, the elastic member 12 of the polishing tool elastically deforms in the Z direction. As a result of the elastic deformation of the hemispherical elastic member 12, the polishing tool and the workpiece L come into surface contact with each other, and the shape of the surface becomes a circle. If the diameter of the circular contact surface is too large, fine processing cannot be performed, so it is preferable that the diameter is 1/5 or less of the diameter of the workpiece L. Further, the elastic member 12 moves relative to the workpiece L, and as a result, a frictional force in the direction opposite to the moving direction X acts on the polishing pad 13,
The elastic member 12 also tries to elastically deform in a direction perpendicular to the rotation shaft 15. However, the elastic member 12
Since the side circumference of is covered with the elastic member frame 14 having rigidity, the elastic member 12 is hardly deformed in the direction opposite to the relative movement direction X of the workpiece L. Therefore, the workpiece L
The contact position of the polishing tool with respect to can be located at a target position.

As described above, in this polishing tool, the contact position of the polishing tool with respect to the workpiece L can be positioned at a desired position without sacrificing the elastic deformation amount of the polishing tool in the pressing direction Z. Therefore, delicate polishing can be performed without applying a local pressure to the workpiece L.

Further, in polishing a general optical element, the surface roughness of the optical element can be adjusted by changing the average pore diameter of the polishing pad 13. Specifically, when the polishing pad 13 has an average pore diameter of about 100 μm, it can be processed with a surface roughness of 0.3 nm to 0.5 nm. The average pore diameter is about 60 μm, and the average particle diameter is 0.5 μm. When the polishing abrasive grains are supplied, the surface roughness can be adjusted to 0.05 nm to 0.1 nm. Further, the polishing amount can be adjusted by changing the thickness of the polishing pad 13 and the hardness of the elastic member 12. However, the polishing pad 13 preferably has a thickness of 2 mm or more so that it can hold a certain amount or more of abrasive grains.

Next, a polishing tool as another embodiment according to the present invention will be described with reference to FIG. This polishing tool is the same as the polishing tool described above, except that the elastic member frame 14a is arranged on the outer periphery of the polishing pad 13 covering the elastic member 12. Therefore, like the polishing tool described above, the contact position of the polishing tool with respect to the workpiece L can be positioned at a target position without sacrificing the elastic deformation amount of the polishing tool in the pressing direction Z.

[0021]

According to the present invention, by providing the strain deformation preventing means or the elastic member frame, the contact position of the polishing tool with respect to the workpiece without sacrificing the elastic deformation amount in the pressing direction of the polishing tool. Since it can be positioned at a target position, delicate polishing can be performed without applying a local pressure to the workpiece.

[Brief description of drawings]

FIG. 1 is a sectional view of a polishing tool according to an embodiment of the present invention.

FIG. 2 is a sectional view of the polishing tool according to the embodiment of the present invention during polishing.

FIG. 3 is a sectional view of a polishing tool as another embodiment according to the present invention.

FIG. 4 is a cross-sectional view of a conventional polishing tool.

FIG. 5 is a cross-sectional view of a conventional polishing tool during polishing.

[Explanation of symbols]

11 ... Support plate, 12 ... Elastic member, 13 ... Polishing pad, 1
4, 14a ... Elastic member frame (strain deformation preventing means), 15 ...
Axis of rotation.

Claims (8)

[Claims] 1. A polishing tool for polishing a workpiece by moving relative to the workpiece while being pressed against the workpiece, a support plate, an elastic member mounted on the support plate, and a polishing member covering the elastic member. A polishing tool, comprising: a pad; and a strain deformation preventing unit that suppresses deformation of the elastic member in a direction component perpendicular to a pressing direction on the workpiece. 2. A polishing tool, which is relatively moved while being pressed by a workpiece to polish the workpiece, a support plate attached to a rotary shaft serving as a rotation center, and an extension line of the rotary shaft as a center. A substantially hemispherical elastic member mounted on the support plate, a polishing pad covering the elastic member, and having rigidity, the elastic member having an opening near an extension line of the rotating shaft and having the rotating shaft as a center. A polishing tool, comprising: an elastic member frame that covers a side periphery of the polishing tool. 3. The polishing tool according to claim 2, wherein the elastic member having a substantially hemispherical shape has a minimum radius of curvature of the elastic member smaller than a minimum radius of curvature of the recess when the workpiece has a recess. Polishing tool characterized by. 4. The polishing tool according to claim 2, wherein the elastic member frame is arranged on the outer peripheral side of the elastic member and on the inner peripheral side of the polishing pad. 5. The polishing tool according to claim 2, wherein the elastic member frame is arranged on the outer peripheral side of the elastic member and the polishing pad. 6. The polishing tool according to claim 1, 2, 3, 4 or 5, wherein the elastic member is silicon rubber. 7. The polishing tool according to claim 1, 2, 3, 4, 5, or 6, wherein the polishing pad is a sponge having a plurality of fine pores. 8. The polishing tool according to claim 7, wherein the sponge forming the polishing pad has an average pore diameter of 5 μm to 500 μm.