JPH04129664A - Polishing method for work - Google Patents

Abstract

PURPOSE:To shorten both net polishing time and changing time of a polishing liquid by changing a polishing liquid fed to a polishing device over to the polishing liquid of small polishing particle from that of a large one under operation of a polishing device. CONSTITUTION:A polishing liquid including the polishing particle which polishes the surface roughness of a work (aluminum substrate for magnetic disk) A in the specified surface roughness, and one kind or plural kinds of polishing liquids including the polishing particle of a relatively large grain size which polishes the surface roughness of a work in the surface roughness larger than that obtained by the use of the polishing liquid are prepared. Then the polishing liquid fed to a polishing device 1 is changed over to the polishing liquid of small polishing particle from a polishing liquid of large polishing particle under the operation of the polishing device 1. The necessary time for polishing the work A in the specified surface roughness can thus be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for polishing a workpiece such as an aluminum substrate for a magnetic disk to a predetermined roughness.

Conventional techniques and problems Conventionally, polishing of aluminum substrates for magnetic disks as described above, for example, uses one type of polishing liquid containing abrasive particles that polish the substrate to a predetermined surface roughness, and this is applied to a polishing device. This was done by rubbing the polishing cloth of the device and the substrate against each other while supplying the polishing material.

However, in the above method, since the polishing process is performed from beginning to end using one type of polishing liquid that polishes the surface to a predetermined surface roughness, it takes a long time for the polishing process. In particular, the surface roughness of the substrate to be polished,
The larger the difference between the desired surface roughness and the polishing process, the longer the time required for the polishing process.

In view of these problems, it is an object of the present invention to provide a polishing method that can shorten the time required to polish a workpiece to a predetermined surface roughness.

Means for Solving the Problems To achieve the above object, the present invention provides a polishing liquid containing abrasive particles for polishing the surface roughness of a workpiece to a predetermined surface roughness;
Using one or more types of polishing liquid containing relatively large abrasive particles that polish the surface of the workpiece to a surface roughness greater than that obtained by using the polishing liquid. The gist of the present invention is a method for polishing a workpiece, which is characterized in that the polishing liquid supplied to the polishing device is switched from a polishing liquid with large abrasive particles to a polishing liquid with small abrasive particles while the polishing device is in operation.

In the above method, it is preferable to supply a rinsing liquid for removing the previous polishing liquid when switching between each polishing liquid.

Effect In the above method, the polishing liquid is changed from one with large abrasive particles to one with small abrasive particles, so that
The net processing time for polishing the surface roughness of the workpiece to a predetermined surface roughness is reduced.

Moreover, since these polishing liquids are switched during operation of the polishing apparatus, the time required for switching the polishing liquid is shortened.

Therefore, the time required from the start to the end of the polishing process is shortened.

EXAMPLE Below, an example of the method of the present invention will be described using an aluminum substrate for a magnetic disk (hereinafter simply referred to as "substrate") (A) as shown in FIG. 3 and as shown in FIGS. 1 and 2. The following description applies to polishing with a planetary gear mechanism type polishing device (1). Note that the workpiece to be polished by the method of the present invention is not limited to the magnetic disk substrate (A), and the polishing apparatus is not limited to a planetary gear mechanism type.

The above-mentioned polishing device (1) includes a lower surface plate (3) that is rotatably and vertically movable and has a donut-shaped polishing cloth (2) attached to its upper surface, and a lower surface plate (3) located above the lower surface plate (3). an upper surface plate (5) which is disposed coaxially opposite to the surface plate (3), is held rotatably and movably up and down, and has a donut-shaped polishing cloth (4) attached to its lower surface; Each polishing cloth (
2) A sun gear (7) disposed at the axial center position of the polishing cloth between (4), and an internal gear (9) concentrically disposed at a position radially outward of the sun gear (7). , the internal gear (9
) and the sun gear (7) and placed on the polishing cloth (2) of the lower surface plate (3).
) (9) and a work carrier (6) formed by an external gear disposed between the two.

Then, the substrate (A) is placed in the holding hole (6a) of the work carrier (6), and the upper and lower polishing cloths (2) and (4) are pressed against both sides of the substrate (A), and the polishing liquid is applied. The work carrier (6) is rotated and revolved around the sun gear (7) by rotating the sun gear (7) while being supplied with The polishing process is performed on both sides of the substrate (A) by rotationally driving the substrate (A).

In the method of this embodiment, two types of polishing liquids and other rinsing liquids are used.

The polishing liquid contains abrasive particles made of alumina, diamond, etc., and one is a polishing solution containing abrasive particles of a particle size that polishes the surface roughness of the substrate (A) to a predetermined target surface roughness. liquid (hereinafter referred to as "small particle size polishing liquid" for convenience). Such abrasive particles have a particle size of, for example, 0.6 to 2
゜Those set within the range of OJB are used.

The other is polishing that includes relatively large abrasive particles to polish the surface of the substrate (A) to a surface roughness greater than that obtained by using the small-particle polishing liquid. liquid (hereinafter referred to as "large particle polishing liquid" for convenience).

Such abrasive particles have a particle size of, for example, 2.0 to 5.
The one set within the range of Oum is used.

Note that a plurality of types of large-particle polishing liquid having different sizes of abrasive particles may be prepared.

The rinsing liquid is supplied to efficiently remove the polishing liquid supplied to the polishing device (1) to the outside.For example, pure water or a liquid containing a surfactant in pure water is used. Ru.

In this embodiment, the substrate (A) is polished as follows. The substrate (A) is placed in the holding hole (6a) of the work carrier (6) of the polishing device (1), and the upper surface plate (5
) and polish both sides of the substrate (A) with upper and lower polishing cloths (2) (
4), start supplying the large-particle polishing liquid, and at the same time remove the sun gear (7) and the upper and lower surface plates (3).
Start rotating (5). The substrate (A) is vigorously polished by supplying the large-particle polishing liquid.

After polishing for a predetermined time while supplying this polishing liquid, while maintaining the rotation of the sun gear (7) and the upper and lower surface plates (3) and (5) as they are, polishing A rinsing liquid is supplied instead of the polishing liquid for a predetermined period of time. This results in
The large-particle polishing liquid remaining in the polishing device (1) is removed to the outside.

Next, the sun gear (7) and the upper and lower surface plates C3)
While keeping the rotation in (5) as it is, this time,
A small-particle polishing liquid is supplied instead of a rinsing liquid. By continuing this for a predetermined period of time, the surface roughness of the substrate (A) is polished to a target surface roughness. With the above steps, the polishing process of the substrate (A) is completed.

If the substrate (A) is polished by the above method, the surface roughness of the substrate (A) will be quickly polished to a certain level of roughness by supplying the large-particle polishing liquid. The net polishing time including the supply polishing time can be shortened, and both polishing liquids are switched sequentially while the polishing device (1) is in operation.
It is also possible to shorten the polishing liquid switching time.

In addition, in the method of this embodiment, the rinsing liquid is supplied after the large-particle polishing liquid has been supplied, so that the large-particle polishing liquid can be quickly removed from the polishing device (1), and the small-particle polishing liquid can be quickly removed from the polishing device (1). At the same time as the supply of the polishing liquid is started, the substrate (A) is polished in an environment where only this small-particle polishing liquid exists, and the polishing time can be shortened by using the small-particle polishing liquid. .

Incidentally, when the substrate (A) was polished by 5 Jjm on one side using a small-particle polishing liquid containing abrasive particles with a particle size of 0.8 JJm, the surface roughness of the substrate (A) was 20 people, and the required time was After polishing the substrate (A) for 6 minutes using a large-particle polishing liquid containing abrasive particles with a particle size of 3.0 mm, a rinsing liquid was supplied for 30 seconds, and particle size 0
The substrate (
When substrate (A) was polished from the initial state to 5 Ja on one side, the surface roughness of the substrate (A) was 25, and the polishing time using a small particle size polishing liquid was 3 minutes. That is, it was confirmed that the time required for the entire polishing process, which took 15 minutes using the conventional method, could be significantly shortened to 9 minutes and 30 seconds using the method of the present invention. In addition, particle size 3. When the substrate (A) was polished by 5uIa on one side using a large-particle polishing liquid containing polishing particles of Ocm, the surface roughness of the substrate (A) was 40 people, and the required time was 7 minutes and 30 seconds. Ta.

Effects of the Invention As described above, the workpiece polishing method of the present invention includes: a polishing liquid containing abrasive particles for polishing the surface roughness of the workpiece to a predetermined surface roughness; Polishing the polishing liquid supplied to the polishing device using a polishing process or a plurality of polishing liquids containing relatively large abrasive particles that polish the surface to a surface roughness greater than that obtained by using a polishing liquid. Since the polishing liquid with large abrasive particles is switched to a polishing liquid with small abrasive particles during operation of the device, both the net polishing time and the time to change the polishing liquid are shortened, and therefore the polishing process is The overall time required from start to finish can be reduced.

[Brief explanation of drawings]

Fig. 1 is a partially sectional side view showing an example of a polishing apparatus used in the method of the present invention, Fig. 2 is a view taken along the line ■-■ in Fig. 1, and Fig. 3 is a magnetic disk to be polished. FIG. (1)...Polishing device, (A)...Aluminum substrate for magnetic disk. (-W

Claims (1)

[Claims] A polishing liquid containing abrasive particles that polishes the surface of a workpiece to a predetermined surface roughness, and polishing the workpiece to a surface roughness greater than that obtained by using the polishing liquid. Contains abrasive particles with relatively large particle size 1
Polishing of a workpiece, characterized in that the polishing liquid supplied to the polishing device is switched from a polishing liquid with large abrasive particles to a polishing liquid with small abrasive particles while the polishing device is operating. Processing method.