JPH02137141A - Stamper for optical information recording medium duplication - Google Patents

Abstract

PURPOSE:To improve quality and to attain massive duplication by composing a stamper of a transparent board, which has a fine rugged pattern on a surface, and a metal film formed on the fine rugged pattern side surface of this transparent board and forming the metal film by a sputtering method. CONSTITUTION:Photo-resist is applied on a glass substrate and after optical writing is executed, the glass substrate is developed. Then, a glass original plate is prepared. After that, for this plate, the metal film is formed on a recording surface (the surface, on which the fine rugged pattern is formed,) by the sputtering method and this plate is defined as a master. Next, photopolymerization molding resin liquid is interposed between this master and the transparent board and a light is radiated from the transparent board side. After the photopolymerization molding resin liquid is set, the transparent board is separated from the master. The metal film is formed in the recording surface side of the transparent board, for which the rugged fine pattern is formed by the photopolymerization molding resin, by the sputtering method. Thus, the quality is improved and the massive duplication can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stamper used for duplicating optical information recording media such as optical discs.

[Problems to be solved by conventional techniques and inventions] Conventionally,
This type of stamper requires two steps: a mastering process in which a photoresist is formed on a glass substrate, laser cutting is performed, and then conductive treatment is performed to produce a glass master; and a mastering process in which a glass master is produced by nickel electroforming on this glass master to form a stamper. It is manufactured through a manufacturing process consisting of a casting process. The stamper manufactured by this manufacturing process has a depth of, for example, 0.11 mm on its surface. , extremely fine uneven patterns such as guide grooves and pits with a width of 0.4 IJa are formed, and only about 1/1 millionth of the total area of the stamper is allowed to have scratches or defects. . In order to manufacture such a stamper, it must be manufactured in a clean room using highly precise technology and with great care. Also,
These steps take several hours to a day or more to complete, and during this time it is necessary to protect the product from dust, dirt, etc. In particular, it is the electroforming process that takes time in this manufacturing process, and there is a high probability that the stamper will be contaminated or defects will occur during this process. It is required to consume a large amount of electric power for a long time, and furthermore, careful attention must be paid to process control for quality control during electroforming. The cost required for these facilities is enormous, and therefore the cost of the stamper increases dramatically.

The present invention has been made in view of the actual state of the prior art as described above, and provides a stamper for duplicating optical information recording media that can be manufactured in a short time at low cost, has good quality, and is suitable for mass duplication. The purpose is to

[Means to solve the problem]

The present inventor focused on the fact that the 2P (photopolymer) method is simple and has good transferability, and used the glass master disk obtained in the first half of the conventional stamper manufacturing process, that is, the mastering process, as a stamper motherboard. As a result of intensive research into omitting the electroforming process by using a copy plate transferred from this glass master plate using the 2P method as a stamper as a mold, the present invention was completed.

That is, according to the present invention, a transparent plate having a fine unevenness pattern on its surface and a metal film formed on the surface of the transparent plate on the side of the fine unevenness pattern, the metal film being formed by a sputtering method. A stamper for copying an optical information recording medium is provided.

The stamper of the present invention is manufactured as follows. First, a photoresist is coated on a glass substrate, optical writing is performed, and then developed to create a glass master disk.A metal film is formed on the recording surface (the surface on which the fine uneven pattern is formed) by sputtering. This is used as the master (the stamper's mother mold).

Next, a photopolymerizable molding resin liquid is interposed between this master and a transparent plate, and light is irradiated from the transparent plate side to harden the photopolymerizable molding resin liquid, and then it is peeled off from the master. Then, a metal film is formed by sputtering on the recording surface side of the transparent plate on which a fine pattern of protrusions and recesses is formed using a photopolymerizable molding resin, thereby obtaining a stamper.

The metal film provided in the mastering conductive process is firmly attached to the glass master disk in the sputtering process and is formed so as not to peel off in the normal 2P method. Similarly, the metal film of the stamper is formed in a sputtering process so as not to peel off using the normal 2P method.

Examples of the transparent plate include glass, tempered glass, polyvinyl chloride/vinyl acetate copolymer, polyvinyl chloride, polycarbonate, polyester, polymethyl methacrylate, polystyrene, cellulose triacetate, cellulose acetobutyralate, etc., and mixtures thereof. can be used. This transparent board is used in thicknesses of 100 mm to 10 ma+.

As the metal film, metals that are not easily oxidized, such as silver, gold, nickel, and chromium, can be used.

The main components of the photopolymerizable molding resin include the following acrylate monomer or methacrylate monomer or oligomer and a photopolymerization initiator.

Representative examples of acrylate monomers and methacrylate monomers include monoacrylates and monomethacrylates, in particular alkyl acrylates, phenyl acrylates, alkoxyalkyl acrylates and phenoxyl acrylates and the corresponding methacrylates, which are particularly suitable representatives. Examples are ethyl acrylate, n-butyl acrylate, i-butyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, dodecyl acrylate, octadecyl acrylate, ethoxyethyl acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate. Acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl acryloyl phosphate, tetrahydrofurfuryl acrylate, stearyl acrylate, lauryl acrylate, N,N-diethylaminoethyl acrylate, N,N-dimethylaminoethyl acrylate, glycidyl acrylate, benzyl acrylate, cyclo Hexyl acrylate, dicyclopentenyl acrylate and the corresponding methacrylates, as well as diacrylates and dimethacrylates, such as 1,3-propanediol diacrylate, 1,3-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,10
-Decanediol acrylate, diethylene diglycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, triprobylene gelicol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, hydroxypivalic acid ester, neopentyl Glycol diacrylate, trimethylolpropane diacrylate, bisoxyethylated bisphenol A diacrylate, bisdi(oxyethylenated) bisphenol A diacrylate, bisoxypropylenated bisphenol A diacrylate, bisdi(oxypropylenated) bisphenol A diacrylate, Mention may be made of 3-methylbentanediol diacrylate and the methacrylates corresponding to the above-mentioned respective acrylates, as well as triacrylates such as trimethylolpropane triacrylate, pentaerythritol triacrylate and the respective corresponding methacrylates, and tris(2-hydroxyethyl ) isocyanates. Furthermore, representative examples of the above-mentioned monomers include acrylates and methacrylates having four or more functional groups, such as dipentaerythritol hexaacrylate, tetramethylolmethanetetraacrylate, pentaerythritol tetraacrylate, and the corresponding methacrylates.

Further, the photopolymerizable molded resin may further contain a sensitizer, a storage stabilizer, a reducing agent, and other additives, if necessary.

Further, as the photopolymerization initiator, conventionally known ones can be suitably used, and representative examples thereof are as follows. Acetophenone, 2,2-jethoxyacetophenone, p-dimethylaminoacetophenone, P-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, PeP'-dichlorobenzophenone, PsP'-bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, Benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-propyl ether,
Benzoin isobutyl ether, benzoin n-butyl ether, benzyl methyl ketal, tetramethylthiuram monosulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, azobisisobutyronitrile, benzoin peroxide, di-tart-butyl peroxide Oxide, p-isopropyl-
α-hydroxyisobutylphenone, α-hydroxy-
Isobutylphenone, dibenzosuberone, diethylthioxanthone, 2,2-dimethoxy-2-phenylacetophenone.

These photopolymerization initiators are used in an amount of 0.05 to 10 parts by weight, preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the above monomer.

The stamper of the present invention is preferably used in duplication methods that require relatively little heat and pressure, such as the 2P method or casting method.0 To reproduce an optical information recording medium using the stamper of the present invention1
A photopolymerizable molding resin liquid is interposed between the stamper of the present invention and a transparent substrate, and the photopolymerizable molding resin liquid is cured by irradiating light from the transparent substrate side, and after peeling from the stamper, a recording layer is formed, For example, it is formed into an air sandwich type structure using a known method.

The recording layer contains 9, Te, In, 5LSb, Se
, Ge, TQ, and other low-melting point metals and alloys, or organic materials such as phthalocyanine, naphthalocyanine, and cyanine can be used.

(Example) Next, the present invention will be explained in more detail with reference to Examples.

First, a glass disk with few defects (diameter 200cm, thickness 8mm
In order to improve the adhesion of the photoresist on the glass disk, a 50% isopropyl alcohol solution of hexamethyldisilazane was applied using a spinner (rotation speed 101,000 rpm), dried, and then the photoresist (Tokyo Ohka Chemical Co., Ltd.) was applied onto the glass disk. After applying 0FPR-8001CP (manufactured by Co., Ltd.), prebaking was performed at 90° C. for 30 minutes.

The film thickness after drying was about 1300. Thereafter, the glass disk on which the photoresist was formed was placed on a master exposure device, and groove recording was performed using light of a wavelength of 457.9 nm from an argon laser. The interval between the recorded grooves is 1, F: μs pitch. Next, the exposed master was immersed in a developer (manufactured by Tokyo Ohka, DE-3), developed until the interference color reached its maximum, immediately washed with pure water, and then incubated at 130℃ for 30 minutes.
Bost bake was performed for 1 minute. Thereafter, this disk was set in a sputtering device, and a nickel film was deposited to a thickness of 500 mm. 10-” T to increase adhesion strength of sputtered film
Sputtering was performed in an Ar atmosphere at orr.

Using the glass master disk obtained in this way as a master, the same glass disk as above was further treated with CH2=CH-C-0-8i-+QC2H5) (
A 0.01% solution was applied and baked at 120° C. for 10 minutes), and transfer was performed using the following 2P solution.

1.6 hexanediol diacrylate 50 parts by weight - tobenzyl dimethyl ketal 3 parts by weight Curing conditions were under high pressure mercury lamp, irradiation power 160 mW/a! (36
0 nm) for 20 seconds, and peeling was performed immediately after the light irradiation. After removing static electricity, it was set in a sputtering device and sputtered under the same conditions as mastering to form a nickel film and obtain a stamper.

Next, 2
In order to improve the adhesion with the P agent, the above 2P liquid was further mixed with brocade in a solvent of toluene/ethyl acetate (weight ratio 1:1) and then dried. Then, using the stamper prepared above, 2P transfer was performed on this acrylic plate in the same manner as above. Then, a film having the following structural formula was formed on the acrylic plate after the 2P transfer to a thickness of 700 mm, and an air sandwich type optical disc was produced by a known method.

When the defects of the optical disc manufactured as described above were evaluated using a defect rate evaluation device, the defect rate was 2
It was as small as 10-'' and was at almost the same level as an optical disk on which 2P transfer was performed using a normal method.Also, the tracking signal was also evaluated.

It was possible to obtain values that were almost the same as those for optical discs produced by conventional methods, and it became clear that there was no difference in transferability.

〔Effect of the invention〕

As described in detail above, according to the present invention, the stamper is constructed by providing a metal film by sputtering on the surface of a transparent plate on which a fine concave-convex pattern is formed.

Because inexpensive materials can be used and the process is shortened, stampers with fewer defects can be supplied in large quantities at low cost. Further, by using the stamper of the present invention, it becomes possible to reproduce a large number of optical information recording media of good quality, and cost reduction is expected.

Patent applicant Rico Co., Ltd.

Claims (1)

[Claims] (1) It consists of a transparent plate having a fine unevenness pattern on its surface and a metal film formed on the surface of the transparent plate on the side of the fine unevenness pattern, and the metal film is formed by a sputtering method. A stamper for duplicating optical information recording media.