JPH09282719A - Washing and drying method for disk and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cleanly wash and dry the entire part of the outside surfaces of a disk. SOLUTION: U-shaped members 6a, 6c disposed at the front ends of three pieces-of disk holding arms 2a to 2c of a rotating body 2 are fixed by holding the three points at the outer peripheral end of the disk 5 from the outer peripheral end face in pressurized contact therewith. The disk 5 held surely by the grooves of the U-shaped members 6a to 6c in such a manner is rotated by a motor 3 and is washed while the washing liquid discharged onto its front surface from a nozzle 8 is spread over the entire part of the front surface by the centrifugal force generated as the disk rotates. The rotation is continued even after the end of the washing by stopping the supply of the washing liquid. Further, the disk 5 is rotated at a high speed and the washing liquid remaining on its front surface is splashed by the centrifugal force, by which the disk is dried. After the high-speed rotation of the disk 5 is maintained for the prescribed time, the rotation is stopped to end the washing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk cleaning / drying method and apparatus, and more particularly to a disk cleaning / drying method and apparatus requiring high cleanliness.

[0002]

2. Description of the Related Art Conventionally, a cleaning liquid (pure water, isopropyl alcohol, etc.) has been used as one of methods and apparatuses for cleaning and drying disks such as stampers for optical disc manufacturing and semiconductor wafers.
There is a disc which is dried by holding the disc washed with the above in a clean environment and evaporating the washing liquid remaining on the outer surface naturally or by using warm air.

However, in this method, a small amount of impurities contained in the cleaning liquid, contaminants once separated from the outer surface of the disc and taken into the cleaning liquid, etc., cause the outer surface of the disc to evaporate. Sometimes remained. In addition, a small amount of dust taken from the air into the cleaning liquid on the outer surface of the disc may remain on the outer surface of the disc after evaporation of the cleaning liquid.

On the other hand, a disc is held on a rotary table which can rotate in a plane, and while the disc is rotated, a cleaning liquid is supplied to the disc surface for cleaning, and the supply of the cleaning liquid is stopped to complete the cleaning. There is also a method and an apparatus for drying the disc by continuing the rotation thereafter and scattering and evaporating the cleaning liquid remaining on the disc surface. This is because the cleaning liquid is mainly scattered by centrifugal force to dry the surface of the disc, so unlike the natural drying (or warm air drying), there is less risk of contaminants remaining on the surface, and high cleanliness is achieved. Used for cleaning and drying required discs.

[0005]

However, in the latter type of cleaning / drying method and apparatus using a rotary table, a part of the back surface of the disk is in contact with the rotary table. The cleaning liquid that entered is difficult to scatter, and there was a problem that impurities and the like existing in the cleaning liquid remained on the back surface even after the disk was dried.

Particularly, in the case of a disk having holes penetrating the front and back surfaces, such a problem is likely to occur because the cleaning liquid supplied to the front surface flows into the back surface through the holes. Also,
In the cleaning process that requires high cleanliness, pre-cleaning is usually performed as a pre-process, but when the disk is held on the rotary table with the cleaning liquid of this pre-cleaning remaining on the outer surface, the above-mentioned problems occur. Becomes noticeable.

Impurities and the like remaining on the back surface of the disc significantly affect the quality of the product, for example, in the optical disc manufacturing process. In the optical disc manufacturing process, a disc-shaped optical disc manufacturing stamper is used to transfer a pattern to a replica to be injection-molded. In order to perform accurate pattern transfer, dust adhered to the outer surface of the optical disc manufacturing stamper is transferred. It is necessary to remove such substances as pollutants before use. In particular, since this optical disk manufacturing stamper molds a replica at a high pressure, it is known that even if dust or the like remains on the back surface, a protrusion is formed on the replica corresponding to the position. Therefore, in order to perform accurate pattern transfer, it is not enough to clean the surface on which the pattern is recorded, and high cleanliness of the entire outer surface of the disc including the back surface is required.

The present invention has been made in view of such conventional problems,
It is an object of the present invention to provide a disc cleaning / drying method and device capable of obtaining high cleanliness over the entire outer surface of the disc.

[0009]

For this reason, in the invention according to claim 1, the disc is held and rotated by a rotating body centered on an axis perpendicular to the plate surface of the disc, and the disc is rotated. In a method for cleaning and drying a disk, in which a cleaning liquid is supplied to clean and dry the disk, the area in which the disk comes into contact with a rotating body is reduced by holding and rotating only a predetermined part of the outer peripheral edge of the disk .

In this respect, a donut-shaped disc such as an optical disc may be held at its inner peripheral edge,
The contaminants and the like taken in from the rotating body through the contact portion with the rotating body provided at the inner peripheral end may spread to the entire outer surface of the disc due to the centrifugal force due to the rotation of the disc. In order to strengthen the holding of the disc on the rotating body, in the invention according to claim 2, a predetermined portion of the outer peripheral end of the disc is gripped and fixed at least from the front and back surfaces of the disc. .

In order to limit the contact area between the rotating body and the disc to a smaller extent, in the invention according to claim 3, a plurality of opposing outer peripheral end faces of the disc are pressed and held and fixed. Further, as in the invention according to claim 4, by holding at least three points on the outer peripheral edge of the disc, the disc can be held more reliably. Further, in the invention according to claim 5, such a cleaning / drying method is applied to a stamper for manufacturing an optical disc to remove impurities and dust from the outer surface thereof.

If the cleaning liquid is supplied while the disc is rotating at a high speed during the cleaning, the cleaning liquid is immediately scattered radially and does not reach the entire surface of the disc, so that sufficient cleaning may not be performed. is there. On the other hand, in order to scatter the residual cleaning liquid by centrifugal force and dry the disc, the rotation speed for cleaning while spreading the cleaning liquid on the disc surface is not sufficient, and in some cases a higher speed is required. is there.

Therefore, in the invention according to claim 6, the rotation of the disk makes the rotation speed during the drying higher than the rotation speed during the cleaning. In this case, in particular, as in the invention according to claim 7, the rotation speed during the cleaning is 100 to 500 rpm, and the rotation speed during the drying is 800 to 1
It is preferable to carry out at 500 rpm.

In order to carry out the above-mentioned method for cleaning and drying a disk, the invention according to claim 8 is an apparatus for rotating and cleaning the disk, which is perpendicular to the plate surface of the disk. A rotating body centered on a different axis, a disk holding means for holding only a predetermined portion of the outer peripheral edge of the disk on the rotating body, a rotation control means for controlling the rotation speed of the rotating body, and the disk. Provided is a disc cleaning / drying device provided with a cleaning liquid supply means for supplying a predetermined amount of a predetermined cleaning liquid to the surface.

Further, in the invention according to claim 9, the disc holding means is configured to grip a predetermined portion of the outer peripheral end of the disc from at least the front and back surfaces of the disc, and the disc is rotated. Hold firmly on the body. And, in the invention according to claim 10, the disc holding means, by holding the outer peripheral end faces of a plurality of predetermined locations of the disc under pressure contact,
The area of contact of the disk with the rotating body is made as small as possible.

Further, in the invention according to claim 11, the disk holding means is configured to hold at least three points on the outer peripheral edge of the disk, thereby making the disk holding more reliable and stable. Further, in the invention according to claim 12, a rotation control means for controlling the rotation speed of the rotating body is included, and the rotation speed is controlled to be suitable for each of cleaning and drying.

Claims for such a cleaning / drying device
According to the thirteenth aspect, there is provided a cleaning / drying device which is particularly suitable for an optical disc manufacturing stamper.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. An example of the disc cleaning / drying apparatus of the present invention is shown in FIG. A rotator 2 having three disc holding arms 2a to 2c as disc holding means is attached to the upper end of an output shaft 4 of a motor 3 in the center of the hood 1 so as to be rotatable in a horizontal plane. Has been. Further, the disk holding arms 2a to 2c project from the outer circumference of the rotating body 2 in the horizontal direction, then bend and extend vertically upward, and have a U-shape having a groove for holding the disk 5 at the tip thereof. Members 6a-6
c.

A nozzle 8 as a cleaning liquid supply means is provided in the hood 1 so as to supply the cleaning liquid pressure-fed by a pump 9 to the upper surface of the disk 5 fixed to the U-shaped members 6a to 6c. Has been. The cleaning liquid may be supplied to a portion of the surface of the disk 5 that is closest to the center of rotation so that the cleaning liquid spreads over the entire surface by the centrifugal force that accompanies the rotation of the disk 5. The control unit 7 controls the rotation speed of the motor 3 to a predetermined value as a rotation control means, and also controls the pump 9 so that a predetermined amount of cleaning liquid is discharged from the nozzle 8 for a predetermined time.

FIG. 1 (b) is a plan view for explaining how the U-shaped members 6a to 6c fix the disc 5. The disc holding arms 2a to 2c are configured to be extendable and contractible in the horizontal direction by air cylinders (not shown) provided in the rotating body 2. The disc holding arms 2a to 2c are U-shaped members 6a to 6c. The three points arranged at equal angles are pressed and held from the outer peripheral end face and fixed. Since the disc 5 is fitted in the grooves of the U-shaped members 6a to 6c, it does not come off during rotation.

If, instead of the U-shaped members 6a to 6c, an L-shaped member 10 as shown in FIG. 2 is used and the outer peripheral end faces of the disk 5 at a plurality of opposing positions are simply pressed and held,
It is possible to further reduce the contact of the rotating body with the front and back surfaces of the disc. Further, when the L-shaped member 10 is used, if the plate-shaped member 11 is brought into contact with the upper surface of the disk 5 and fixed to the L-shaped member 10 with the screw 12, the outer peripheral end surface It is possible to fix the disc 5 by gripping and holding it by pressure contact from the outer peripheral end face, and more reliably hold it while limiting the contact area to a small value.

The number and method of contact points for holding the disk on the rotating body may be determined in consideration of the area, weight and material of the disk. For cleaning, while rotating the disc 5,
Although the cleaning liquid is supplied to the upper surface of the disk, if the rotation speed of the disk 5 is too high, the cleaning liquid may be scattered at once, and sufficient cleaning may not be performed.
Rotate at low speed from 00 to 500 rpm.

After a predetermined amount of cleaning liquid is discharged from the nozzle 8 for a predetermined time, the supply of the cleaning liquid is stopped and the cleaning is completed.
Then, the drying is started. In order to scatter the cleaning liquid remaining on the surface of the disk 5 by centrifugal force, a low speed rotation similar to the above-described cleaning is not sufficient and a higher rotation speed is required, but the cleaning liquid is dissipated above a certain speed. Since the effect will reach the ceiling, considering safety, 800-1500 rpm is preferable.

After the high speed rotation of the disk 5 is maintained for a predetermined time, the rotation is stopped. In such a drying method utilizing the rotation of the disc, there is also an effect of drying by evaporation of the cleaning liquid spread extremely thinly on the surface of the disc by the centrifugal force, but mainly the one that is scattered from the outer peripheral edge by the centrifugal force. Therefore, it is less likely that contaminants and dust contained in the cleaning liquid will be scattered at the same time and remain on the surface of the disc.

Further, in the cleaning / drying apparatus of the present invention, since both the front and back surfaces of the disk have a small area of contact with the rotating body, the cleaning liquid adhered to the back surface in the preliminary cleaning and the holes penetrating the front and back surfaces of the disk are formed. The cleaning liquid that has spilled over to the back surface also quickly scatters together with the dust and impurities contained therein, and no dust or the like remains after drying. Further, in order to prevent dust in the air from being taken into the cleaning liquid supplied to the surface of the disc 5 as much as possible, this device should be installed and used in a clean environment such as a clean room. desirable.

FIG. 1 shows an example in which the axis of the rotating shaft is provided in the vertical direction, but the rotating shaft of the disc may be inclined or perpendicular to the vertical direction. In such a case, the supply position and method may be appropriately changed so that the cleaning liquid spreads over the entire surface of the disk, for example, by spraying and supplying the entire surface of the disk. If the cleaning liquid is also jetted and supplied to the back surface, the entire outer surface of the disc can be cleaned more reliably.

Next, an experiment was carried out to confirm the effects of the cleaning / drying method of the present invention, using a stamper for optical disk production as a disk. Generally, an optical disc manufacturing stamper is manufactured as follows. First, the photoresist uniformly applied on the optically polished glass substrate is subjected to patterning, and a master is produced on the photoresist by an electroforming process. Then, the master is peeled from the glass substrate, the photoresist remaining on the surface of the master is removed, and the master is thoroughly washed, and then the protective lacquer is applied to the pit forming surface of the master. Furthermore, after polishing the back surface of this master, it is punched into an appropriate shape to form a stamper. The above-mentioned protective lacquer is peeled off from this stamper, the appearance is checked and the signal characteristics are measured, and those having no problem are used in the replica manufacturing process.

Here, in order to verify the effect of the cleaning / drying method of the present invention, the peeling of the protective lacquer is insufficient and the protective lacquer remains to the same degree, and there is a problem in terms of appearance inspection and signal characteristics. The following experiment was performed by selecting three sheets. First, in order to remove the lacquer left on the surface, this 3
The stamper was immersed in a warm alkaline solution and thoroughly washed with pure water. Then, the method of applying the cleaning / drying method of the present invention and the method of applying the two conventional methods of cleaning / drying were separately performed for cleaning / drying.

The stamper to which the cleaning / drying method of the present invention is applied is set in the apparatus of the present invention shown in FIG. 1, and while being rotated at 200 rpm, pure water as a cleaning liquid is applied to the innermost peripheral portion of the stamper for 20 seconds. It was supplied and washed. The amount of pure water used is approximately
It was 700 ml. Then, it was rotated at a high speed of 1000 rpm to scatter the pure water remaining on the surface and dried. Since there is a portion irrelevant to data recording near the outer circumference of the optical disk manufacturing stamper, if it is held by using this portion, there is little risk of affecting the subsequent manufacturing process. This stamper is referred to as sample A.

Next, a hot air drying method, which is one of the conventional washing and drying methods, was applied to one of the stampers washed with pure water. Specifically, as shown in FIG.
Air (corresponding to class 100) passed through the PA filter 21 (clean room filter) was heated by the heater 22 and was applied to a stamper placed downstream to dry it. This stamper is referred to as sample B.

Finally, the remaining one of the stampers washed with pure water is set and rotated on a rotary table 32 having a boss portion 31 fitted in the center hole of the stamper as shown in FIG. And dried. This stamper was used as sample C. The signal characteristics of each sample before and after cleaning and drying were measured, and the error rate comparisons are shown in FIG. Although the error rate is reduced in the sample A to which the cleaning / drying method according to the present invention is applied, the error rate in the sample B and the sample C is higher than that before the cleaning / drying.
On the contrary, when the drying method is used, the surface of the stamper is contaminated.

Further, since it is known that protrusions are generated on the replica corresponding to the dust or the like existing on the back surface of the stamper, the replicas are manufactured using the stampers of Sample A, Sample B and Sample C, respectively. , And compared the number of protrusions produced on the replica. The results are shown in FIG. It was confirmed that there were no protrusions on the replica produced from the stamper of Sample A to which the cleaning / drying method of the present invention was applied, the back surface of the stamper was also cleaned cleanly, and no dust remained after drying. On the other hand, sample B using the conventional washing and drying method
Also, it can be seen that the replica produced from the stamper of sample C had protrusions, and that dust and the like were attached to the back surface of the stamper after drying.

As described above, according to the cleaning / drying method of the present invention, both the front and back surfaces of the stamper are cleanly cleaned, so that it is possible to manufacture a high quality replica in terms of signal characteristics and appearance.

[0034]

As described above, according to the invention of claim 1 or 8, the contact area between the disc and the rotating body for rotating the disc is reduced, and the disc remains on the outer surface of the disc. By making it easier to scatter the cleaning liquid, it is possible to prevent contaminants and dust from remaining on the outer surface of the disk after drying. Further, since the disc can be washed and dried continuously, it is possible to prevent contaminants and the like from adhering to the washed disc again without human intervention when shifting from the washing process to the drying process. There is also an effect that it can be prevented and the working time can be shortened.

Further, according to the invention of claim 2 or claim 9, since the mutual contact area between the disk and the rotating body can be reduced and the disk can be firmly held, it is possible to perform cleaning and drying. This has the effect of reliably preventing the disc from coming off due to rotation. Further, according to the invention as claimed in claim 3 or claim 10, the contact area between the disc and the rotating body can be restricted to be smaller, so that the efficiency of removing the cleaning liquid can be increased and contaminants and the like can be surely left. The effect is that it can be prevented.

According to the invention of claim 4 or claim 11, the effects of the inventions of claims 2 and 9 can be further enhanced. Further, according to the invention of claim 5 or claim 13, since the stamper for manufacturing an optical disk can be easily cleaned and dried with extremely high cleanliness, a high quality replica can be manufactured and the defective product rate can be improved. There is an effect that it can be significantly reduced.

Further, according to the invention of claim 6 or claim 12, by appropriately adjusting the rotation speed of the disc,
It is possible to prevent the cleaning liquid supplied at the time of cleaning from splashing all at once, and to perform effective cleaning, and at the time of drying, make sure that the cleaning liquid remaining on the surface of the disc and the contaminants and dust that have dissolved in it The effect is that it can be eliminated.

Further, according to the invention of claim 7, there is an effect that it is possible to select a rotation speed in an appropriate range and prevent accidental damage of the disk due to unnecessary high speed rotation.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a cleaning / drying apparatus of the present invention.

FIG. 2 is a diagram showing another embodiment of a disc holding method.

FIG. 3 is a diagram showing a conventional drying method using warm air.

FIG. 4 is a diagram showing a conventional drying method using a rotary table.

FIG. 5 is a graph showing a difference in signal error rate before and after cleaning / drying by each method.

FIG. 6 is a diagram showing a comparison of the number of protrusions generated on a replica produced from a stamper to which each cleaning / drying method is applied.

[Explanation of symbols]

 2 Rotating body 2a to 2c Disc holding arm 3 Motor 5 Disc 6a to 6c U-shaped member 7 Control unit 8 Nozzle

Claims (13)

[Claims] 1. A disk cleaning method in which the disk is held and rotated by a rotating body centered on an axis perpendicular to the disk surface, and a cleaning liquid is supplied to the disk surface for cleaning and drying. -In the drying method, the disk is washed and dried by holding and rotating only a predetermined portion of the outer peripheral edge of the disk. 2. The circle according to claim 1, wherein the disc is held on the rotating body by gripping a predetermined portion of the outer peripheral edge of the disc from at least the front and back surfaces of the disc. How to wash and dry plates. 3. The disk according to claim 1, wherein the disk is held by the rotating body by pressing and holding the outer peripheral end faces of a plurality of opposing positions of the disk. Washing and drying method. 4. The disk according to claim 1, wherein at least three points on the outer peripheral edge of the disk are held.
Disc cleaning and drying method 5. The disk according to claim 1, wherein the disk is a stamper for manufacturing an optical disk.
Disc cleaning and drying method 6. The rotation speed of the disk is higher in the drying operation than in the cleaning operation. Disc cleaning and drying method. 7. The rotation speed during the cleaning is 100 to 500 rp
m, the rotation speed during the drying is 800-1500 rpm
7. The method for cleaning / drying a disc according to claim 6, wherein 8. An apparatus for cleaning and drying by rotating a disc, comprising: a rotating body having an axis centering on an axis perpendicular to the plate surface of the disc and only a predetermined portion of an outer peripheral end of the disc. A disc cleaning / drying apparatus comprising: a disc holding unit that is held by the rotating body; and a cleaning liquid supply unit that supplies a predetermined amount of a predetermined cleaning liquid to the surface of the disc. 9. The disc holding means holds the disc on the rotating body by gripping a predetermined portion of the outer peripheral edge of the disc from at least the front and back surfaces of the disc. 9. The disk cleaning / drying device according to claim 8. 10. The disc holding means holds the outer circumferential end faces of a plurality of predetermined locations of the disc, which are opposed to each other, by pressing.
The disk cleaning / drying apparatus according to claim 8 or 9, wherein the disk is held by the rotating body. 11. The disc according to claim 8, wherein the disc holding means holds at least three points on an outer peripheral edge of the disc. Cleaning and drying equipment. 12. The disk cleaning / drying device according to claim 8, further comprising a rotation control unit that controls a rotation speed of the rotating body. . 13. The disk according to claim 8, wherein the disk is a stamper for manufacturing an optical disk.
Disc cleaning and drying device