JPH0675824B2 - Polishing tool - Google Patents

Description

The present invention relates to a polishing tool for polishing the surface of an object such as metal, ceramics, glass or the like with a working fluid containing fine particles.

<Prior Art> When finishing the surface of an object of various materials into a mirror surface, while spraying a machining liquid containing fine particles of diamond, alumina, silicon oxide, etc., that is, a polishing agent, the tool surface and the object surface A so-called polishing method, which is a method of processing by rubbing each other, is adopted.

The conditions required for the polishing tool used for this polishing are:
Holds the fine particles moderately and has elasticity because the contact area with the work surface is large, keeps the lubricity between the work surface and the tool surface, and holds the working fluid for cooling the working system. Good resistance, good abrasion resistance,
For example, the workability of the tool material itself is good.
In the past, foamed polyurethane non-woven fabric, polyvinyl chloride resin, nylon resin, fluorine resin and soft metals such as tin and lead have been used to satisfy these conditions relatively well. There is.

<Problems to be Solved by the Invention> However, conventionally used resin materials generally do not have good wettability with water and do not satisfy the above conditions (1) and (2). Therefore, for example, in the case of foamed polyurethane, a special treatment is used to foam and form a minute opening in the surface, and the processing liquid and particles are held in this opening, so that a semiconductor such as Si or GaAs is formed. It is used as a polishing tool. However, in such a tool, there is a problem that the life of the specially processed portion of the surface is short, and there is also a problem that the periphery of the processed surface is sagged because the elastic coefficient of the foam layer is too small.

On the other hand, when a hard resin such as a polyvinyl chloride resin, a nylon resin, a fluorine resin, or a soft metal such as tin or lead is used, a spiral or The lattice-shaped grooves are formed. However, since the wettability of the material itself is originally poor, the following various problems occur. That is, the machining fluid becomes a polka dot, and the particles agglomerate in the polka dots and adhere to the tool surface, making it difficult to uniformly disperse the particles on the tool surface, and to achieve uniform machining in a microscopic view. Absent.

Since relative slip occurs between the rotating tool surface and the machining fluid,
The momentum of fine particles with respect to the surface to be processed cannot be increased.

The machining fluid is immediately shaken off from the rotating tool surface by the centrifugal force and does not work effectively between the tool surface and the surface to be machined.

When the particles do not uniformly act on the entire machined surface as described above, the machining efficiency becomes low, and the particles as a mass act to leave a local scratch or strain on the machined surface.

An object of the present invention is to provide a polishing tool that solves the above-mentioned problems.

<Means for Solving the Problem> A polishing tool of the present invention that achieves the above object is a disk-shaped tool for polishing a surface of an object while holding a working fluid containing fine particles between the object surface and It has a uniform resin composition in the thickness direction and is composed of an integral structure composed of cellulose-based resin whose main component is nitrocellulose-based fibrin, and has spiral or radial slanted grooves on the disk-shaped surface. Is provided.

The configuration of the present invention will be described in detail below.

In the present invention, the cellulosic resin containing nitrocellulose-based fibrin as the main component is a resin containing nitrocellulose-based fibrin as the main component, and preferably 10 to 90 Camphor 10 to 50% polymerization by weight%
And 20 to 60% by weight of ethanol.

Further, the nitrocellulose-based fibrin here means cellulose nitrate, cellulose acetate and the like. Such fibrin has, for example, the following chemical formula: As shown in, it has a hydroxyl group as a functional group.

Therefore, the cellulosic resin containing such a fibrin as a main component has very good wettability with water. Further, although the resin has a hydroxyl group, it is insoluble in water and only slightly swells with alkali. On the other hand, the hard resin used conventionally does not have a hydroxyl group and therefore has poor wettability. For example, comparing the contact angle, which is a measure of the quality of wettability, is about 60 degrees for the cellulose resin of the present invention, 87 degrees for the polyvinyl chloride resin, 70 degrees for the nylon resin, and fluorine series. It is 90 degrees or more for resin. As described above, since the cellulosic resin of the present invention has a good wettability which has never been obtained, it has a uniform resin composition in the thickness direction and is composed of an integral structure made of such cellulosic resin. In a polishing tool having a spiral groove or a radial inclined groove on the disk-shaped surface, the action of the machining liquid on the surface to be machined is made uniform, and good machining characteristics can be obtained. In addition,
The polishing tool according to the present invention is preferably formed into an uneven surface having a surface roughness of 0 to 50 μm.

<Examples> Hereinafter, the present invention will be described based on Examples.

(Embodiment 1) FIG. 1 is an embodiment of a polishing method by a polishing apparatus using a disk-shaped polishing tool of the present invention. As shown in the figure, the polishing tool 11 is a 2 mm thick celluloid plate obtained from cellulose nitrate, which is a type of cellulose ester, and the polishing tool is adhered to the surface of the iron surface plate 12 with an adhesive 13. After doing
Formed flat by turning and further pitched on a disk-shaped surface
A spiral groove 14 having a width of 2 mm, a depth of 0.5 mm and a width of 0.5 mm is formed.

The sample to be processed adhered to the adhesion substrate 15 on the polishing tool 11.
That is, 16, that is, a Si wafer is placed, and while the processing liquid 17 is added dropwise to the mating surface, the surface plate 12 is rotated and the adhesive substrate 15 is rotated to perform polishing.

In this embodiment, the working liquid 17 is a weak alkaline liquid having a pH of about 12,
O ₂ particles were suspended, the rotation speed of the platen 12 was about 60 rpm, a load was applied to the adhesive substrate 15, and a polishing pressure of about 200 gr / cm ² was applied to the sample 16 to be processed. .

In this example, the processing efficiency is 0.5 μm / min, which is 30% compared to the conventional method.
The efficiency is high at about%, and the flatness of the machined surface is 1 μm or less / φ4 inch. In addition, since only the surface layer of the tool swells slightly due to weak alkali, the effect on the surface to be machined is made uniform and the surface is softened, and the surface roughness of the machined surface is less than 10Å, which is 50% of that of the conventional method.
Was also improved, and no residual processing strain was observed.

(Embodiment 2) FIG. 2 shows another disk-shaped polishing tool according to the present invention.
As shown in the figure, the polishing tool 21 is made of a cellulose-based resin composed of cellulose acetate, camphor and ethanol. The surface of the polishing tool 21 is radially divided, and inclined grooves 23 whose depth gradually changes along the rotational direction are formed between the flat portions 22.

FIG. 3 shows an embodiment of a polishing method using a polishing apparatus equipped with such a polishing tool 21. As shown in the figure, a sample 31 made of a plurality of Si wafers is placed on a polishing tool 21 rotatably supported in an outer cylinder 30. Each sample 31
Are inserted between supporting cylinders 34 which are bonded to the sample bonding substrate 32 and are provided on the supporting plate 33 so as to be respectively rotatable, and are each rotated on the rotating polishing tool 21.

Rotate the tool 21 at about 60 rpm with the working liquid 35 in which fine particles of SiO ₂ are suspended in a weak alkaline liquid with a pH of about 12 placed in the outer cylinder 30 and immersed in the working surfaces of the polishing tool 21 and the sample 31. Let At this time, the machining liquid sandwiched between the flat surface of the sample 31 to be machined and the flat portion 22 and the inclined groove 23 on the tool surface.
Since 35 moves continuously from the deep part of the inclined groove 23 with a large gap to the flat part 22 with a small gap, dynamic pressure is generated by the action of hydrodynamics,
The processed surface of the sample 31 floats above the tool surface. Since the processing liquid 35 contains fine particles, the Si wafer surface is processed by the collision action of the fine particles and the like.

In this way, since the polishing tool is made of a cellulose-based resin consisting of cellulose acetate, camphor and ethanol, which have good wettability, the relative slip between the rotary tool surface and the machining fluid is reduced, The machining fluid moves with the movement of the tool surface, and the momentum with respect to the surface to be machined also increases, improving the machining efficiency by 30 to 50% compared to the conventional method.
Further, the flatness and surface roughness of the machined surface were improved to the extent of Example 1, and no residual machining strain was observed.

<Effects of the Invention> As described above, by using a cellulosic resin whose main component is a nitrocellulose-based fibrin as a material for a surface polishing tool of various materials, the tool has a high hydrophilic property. The wettability of the machining fluid to the surface is improved, and the machining fluid is evenly distributed over the entire tool surface.

Further, since it is composed of the integral structure of the above cellulose-based resin, it has a uniform resin composition in the thickness direction and can form a spiral groove or a radial inclined groove on the disk-shaped surface. . By forming such a groove, dynamic pressure is generated due to hydrodynamic action from the groove due to high-speed relative movement, and the machined surface of the sample floats above the tool surface and becomes contacted. As a result, the fine particles in the working liquid are made uniform on the work surface of the sample, the polishing efficiency of the sample is improved by the collision action of the polishing fine particles, and a soft finishing surface with few scratches can be easily obtained. is there.

[Brief description of drawings]

1 to 3 are explanatory views showing an embodiment of the present invention. In the drawing, 11,12, are polishing tools, 16,31 are samples to be processed, and 17,35 are working fluids.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadao Saito 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (56) References Showa 48-94287 (JP, U) Show 55-156864 (JP, U)

Claims (1)

[Claims] 1. A disk-shaped polishing tool for polishing a surface of an object while holding a working fluid containing fine particles between the surface of the object and cellulose containing nitrocellulose as a main component and containing fibrin as a main component. A polishing tool comprising an integrated structure made of a system resin, having a uniform resin composition in a thickness direction, and having a spiral groove or a radial inclined groove on a disk-shaped surface.