Scrubbing device and roll sponge assembly used therein

Abstract

A roll sponge assembly for a scrubbing device includes a support having a support portion and a rotary shaft provided on two ends of the support portion, and a roll sponge having a hollow hole for holding the support by fitting the support portion of the support into the hollow hole. An outer diameter of the roll sponge assembly continuously or in stages increases in a lengthwise direction thereof.

Description

BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT[0001]The present invention relates to a scrubbing device for cleaning a circular or a rectangular plate such as a magnetic disc substrate made of metal, glass or the like, a semiconductor wafer, and so on, and a roll sponge assembly used in the scrubbing device.[0002]In recent years, magnetic disk drives have become smaller in size and expanded their range of applications, while it has been always demanded to further increase a recording density of a magnetic disc installed in the drive. A magnetic disk is manufactured by forming thin films such as a magnetic layer on a substrate made of glass or a metal such as aluminum. With regard to this type of magnetic disk, major progress has been made, in response to the demands described above, for the development of a substrate capable of reducing the distance (magnetic spacing) between a magnetic head and the magnetic disk. As disclosed in Patent Document 1: Japanese Unexamined Patent ...

AI Technical Summary

Benefits of technology

[0018]In the present invention, the pressing force of the roll sponge in the roll sponge assembly of the scrubbing device against a cleaning substrate can be varied continuously in accordance with the movement of the substrate by varying the outer diameter of the roll sponge. In other words, by moving the cleaning substrate in the lengthwise direction of the roll sponge as scrubbing process goes on, a pressing force corresponding to the cleaning stage can be provided between the roll sponges. Furthermore, in the present invention, the substrate is moved in the lengthwise direction, and therefore different parts of the roll sponge can be continuously used in accordance with the each cleaning stage.

[0019]Moreover, in the present invention, only the outer diameter of the roll sponge for the scrubbing device needs to be varied. Therefore highly effective scrubbing corresponding to the cleaning stage can be provided during substrate cleaning without making the device further complicated.

Problems solved by technology

However, when particles are adhered to the substrate, a high degree of smoothness cannot be obtained regardless of the precision with which the substrate is polished, and therefore the cleaning method employed after the precision polishing is extremely important.

Therefore, with respect to the required level of the cleanness and the size of the particles, it is extremely difficult to maintain a high level of cleaning quality at all the time.

As disclosed in Japanese Unexamined Patent Application Publication No. 2002-74653, with ultrasonic cleaning alone, comparatively large polishing agent residue can be removed, but it is still difficult to reliably remove minute residue such as those described above, and therefore a plurality of cleaning tanks is necessary, thereby increasing the cleaning time which adversely affects productivity.

(1) It is difficult to optimize the pressing force of the sponge against the substrate.

(2) When particles accumulate on the sponge, the substrate becomes recontaminated by the particles.

(3) A device for performing multi-stage scrubbing and overcoming problems (1) and (2) is large.

Problem (1) is due to the fact that particles of various materials and sizes become adhered to the cleaning target substrate.

Furthermore, debris generated by substrate shavings and polishing pad shavings during polishing, dust produced by a device driving portion, and the like also become adhered to the substrate.

As regards problem (2), during the course of scrubbing, a roll sponge attached to a device processes a large amount of substrates, and therefore particles gradually accumulate on the roll sponge.

As a result, a predetermined level of cleaning quality can no longer be obtained.

Furthermore, as noted above in relation to problem (1), particles of various sizes, shapes and materials become trapped on the roll sponge, and therefore, depending on the trapped particles, defects such as scratches are caused continuously on the surface of subsequently processed substrates, thereby undermining the cleaning quality.

However, since a series of devices, each comprising a driving portion, is required, such a device occupies a large amount of space and is not easy to maintain.

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