JPS63298731A - Production of stamper for reproduction of optical recording substrate - Google Patents

Abstract

PURPOSE:To obtain a reproduced substrate having excellent quality in appearance or electrical characteristics by stripping a stamper from a glass substrate, then subjecting the recording surface of the stamper to an electrolytic degreasing and further, chemical polishing or electrolytic polishing treatment. CONSTITUTION:After a photoresist is applied on the polished surface of the glass substrate, the resist is exposed by a laser and is further developed to form pits or grooves on the surface; thereafter, the resist surface is subjected to a conducting treatment by silver or nickel sputtering, then to nickel electrocasting and polishing on the rear face. The recording surface of the stamper stripped from the glass substrate is subjected to the electrolytic degreasing and further chemical polishing or electrolytic polishing treatment. The stamper which has less defects in the appearance or electrical characteristics is thereby easily produced and the characteristics of the repro duced disk are greatly improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for manufacturing a stamper for mass-producing optical recording substrates such as compact discs (hereinafter referred to as CDs) or magneto-optical discs. It is something.

[Summary of the invention]

The present invention is a manufacturing method for replicating a substrate for an optical recording medium, in which a photoresist is coated on the surface of a polished glass substrate, exposed with a laser, developed to form pits or groups, and then coated with silver or nickel. Conductive treatment by sputtering, then nickel electroforming, back polishing, electrolytic degreasing of the recording surface of the stamper that has been peeled off from the glass substrate, and further chemical polishing or electrolytic polishing to improve appearance and electrical properties. Meta/bars with few defects can be easily produced, and the characteristics of the duplicated disks are greatly improved. This is what made it possible.

[Conventional technology]

The conventional manufacturing method for a stamper for duplicating optical recording substrates is to uniformly apply 7-photoresist to the required a-millimeter area using a spin cord on a surface-polished glass substrate, then expose it to light using a laser cutting machine after pre-baking, and then develop it. to form arbitrary pits or groups. After sputtering tin or nickel onto this substrate and making it conductive, nickel electroforming was applied to the
The process is carried out to a uniform thickness and surface roughness by cutting the back surface.

This nickel electroformed layer is peeled off from the glass substrate and after processing the inner and outer diameters, the resist is removed and washed with a solvent, and in the case of silver sputtering, a silver peeling treatment is performed to complete the stand bar.

[Problem that the invention seeks to solve]

However, in the prior art described above, when the stand bar is peeled off from the glass substrate, the photoresist is firmly attached to the recording surface of the stand bar, and it is difficult to remove the resist only by cleaning with a solvent. Even when ultrasonic waves are used in combination, it cannot be completely removed, and a thin film of tatin remains on the surface of the stubber, resulting in poor quality of molded substrates using this stambar.

In addition, with silver sputtered products, the mechanical coating on the surface did not allow enough silver to be peeled off, resulting in the problem of silver remaining.

Furthermore, when looking at the surface of a stand bar manufactured by the conventional process, there are fine irregularities on the order of several tens of degrees, which causes noise and errors in the molded substrate.

The present invention is intended to solve these problems, and its purpose is to completely remove impurities such as mechanical coating from the recording surface of the stand bar, and to make the pit or group surface smoother. The aim is to significantly improve the quality of the final molded substrate.

[Means for solving problems]

The method for manufacturing a stanbar for duplicating an optical recording substrate of the present invention includes:
A photoresist is formed on the surface of the glass substrate, and the resist is exposed and developed with a laser to form a predetermined pattern such as pits and groups.The glass master is sputtered with silver, nickel, etc. to make it conductive, and then electroformed after nickel electroforming. By peeling the layer from the glass substrate? In the process of manufacturing a standbar for use by JI, the recording surface of the standbar is electrolytically cleaned and further treated by chemical polishing or electrolytic polishing after the standbar is peeled off.

[Effect]

According to the present invention, meta/bar is transferred from a glass substrate to Ill.
After machining the inner and outer diameters, the photoresist layer adhering to the stanbar surface is first decomposed by the alkaline content of the degreasing solution through electrolytic degreasing, and then physically removed by hydrogen or oxygen generated on the stanbar surface by electrolysis. Also photoresist? A separating force acts, and the 7-otoresist can be easily and completely removed from the stand bar surface.

Furthermore, by performing chemical polishing or electrolytic polishing, the pit and group surfaces are smoothed, making it possible to greatly improve the quality of the molded disk substrate, including its appearance, noise, and error reduction. Ta.

〔Example〕

First, on an optically polished glass substrate with an outer diameter of 240 mm, an inner diameter of 15 mm, and a thickness of 6 mm, a positive resist (AZ1350 from Hoechst) was applied to a thickness of 1,200 mm using a spinniter, and the pre-baked TLCD master tape information The exposed resist layer is removed by exposure and development with modulated laser light.

After post-baking this glass master, a 1000 nickel film is sputtered to make it conductive, and then nickel electroforming is performed using a nickel sulfamate plating bath to form a nickel layer with a thickness of about 300μ. After that,
The back surface was polished, peeled from the glass substrate, and the inner and outer diameters were processed to create a stand bar.

This stanbar was subjected to electrolytic degreasing treatment under the following composition and conditions.

Soda carbonate・・・・・・・・・30g/β caustic soda・・・・・・・・・10g/! 2 Sodium triphosphate...10 g/(1 temperature...)
・・・・・・・・・60~70°C current density...
・・・・・・・・・・・・・・・5 A/d m' treatment time・・・・・・・・・・・・・・・1 minute (anodic treatment) This treatment will reduce the surface of the stand bar. The resist could be easily and completely removed.

Next, electrolytic polishing treatment was performed. The composition conditions of the treatment liquid were as follows.

Phosphoric acid...800cc Sulfuric acid...200cc Bath temperature...40~50@C current density...
2 A / d m 'Processing time: Using a stambar completed after 5 seconds or more of processing, a disk substrate was molded and the appearance was inspected, comparing it with a stambar manufactured using a conventional process. When we measured the electrical characteristics, we found that in terms of appearance, the conventional stanbar has a 11-ira color on the stanbar surface and 30% cloudiness.
However, with the stubber of the present invention, no occurrence occurred at all, and a good product could be obtained from the first stump bar.

In terms of electrical characteristics, the block error rate of CDs molded using the stand bar of the present invention is constantly on average 10.
The following (number of error frames out of 7,350 frames) can now be obtained.

In addition, very good eye patterns and tracking error signals were obtained.

〔Effect of the invention〕

As explained above, in the process of manufacturing a stand bar by exposing and developing the 7-photoresist on a glass substrate, making it conductive, performing nickel electroforming, and separating the electroformed layer from the glass substrate, After peeling off the meta/bar from the glass substrate, the recording surface of the stand bar is electrolytically degreased, and then subjected to chemical polishing or electrolytic polishing to completely remove the remaining photoresist on the recording surface and remove any pits or group surfaces. By making it smooth, it has become possible to easily manufacture a stand bar for obtaining a replicated substrate with excellent quality in terms of appearance and electrical properties.

In the present invention, similar effects can be obtained with other scrubber materials, treatment liquid compositions, and conditions other than those in the examples.

that's all

Claims (1)

[Claims] A photoresist is formed on the surface of the glass substrate, and the resist is exposed and developed using a laser to form a predetermined pattern such as pits and groups onto a glass master.
In the step of manufacturing a stamper for substrate duplication by peeling off the electroformed layer from the glass substrate after nickel electroforming, after peeling off the stamper from the glass substrate, electrolytically cleaning the stamper recording surface, A method for producing a stamper for duplicating an optical recording substrate, which further comprises chemical polishing or electrolytic polishing.