JPS58153242A - Manufacture of original disk for phonographic or recording disk - Google Patents

Abstract

PURPOSE:To improve S/N at signal reproduction, by forming a dielectric layer with good adhesive strength between a photoresist film and a substrate. CONSTITUTION:On the substrate 1, a negative resist layer 10 made of the dielectric layer and positive resist are provided. In this case, a metallic thin film 14 is interposed to increase the adhesive strength between the substrate 1 and negative resist layer 10. Then, the positive resist 3 is irradiated with a laser light beam 5 converged through an optical system 4. Then, development is carried out by using a developer for a positive type to remove the resist layer in an exposure area 12 while the resist layer in an unexposed area, forming a recessed and projecting pattern 15. The formation the recessed and projecting pattern of the photoresist is caused by one of an increase in moledular weight due to polymerization, an increase in molecular weight due to cross-linking, cross-linking polymerization wherein cross-linking occurs simultaneously, and a decrease in molecular weight. Further, any dielectic layer, such as urethane, chloroprene, and nitrile butadiene, having superior adhesive strength to the substrate and positive resist film is usable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a method for manufacturing a master disc for a sound disc or recording disc on which high-density information is recorded. q#, this invention is
The present invention relates to a method for forming a photoresist film to be coated on the surface of a glass substrate before producing a master disc for a sound disc or a recording disc.

[Prior art and its problems]

Conventionally, master discs for sound discs and recording discs have been manufactured as follows. After providing a positive resist film on a glass substrate, prebaking is performed. When recording high-density information, negative dust resists have excellent adhesion and adhesion to the substrate, but on the other hand, it is difficult to obtain patterns with high density, that is, high resolution. A mold resist is used.

However, positive resists have poor adhesion and adhesion to the substrate, and often use a subbing layer of a thin metal film such as a chromium film. While rotating the glass substrate coated with resist, it is exposed to a fine laser spot and the resist is exposed to light. The material is then developed and after-baked and used as a master disc for sound discs and recording discs.

However, pinholes in the undercoat metal film and associated detachment of the positive resist layer from the glass substrate become a source of noise in the master, so it was essential to provide a uniform film without pinholes. This means that the master disc for sound discs and recording discs (
7) The higher the density of the information written on the resist film, the thinner the resist film, the more noticeable the effects of defects such as holes and pinholes. Furthermore, the defects generated in the master disk are aggravated each time electroforming is repeated when replicating the stamper, further reducing the 8/N ratio.

For example, the master disc for the still image flaw information file (FIG. 2-b) is provided with a guide groove (9) for tracking. Assuming that copying to a stamper, plastic molding, etc. are carried out ideally, the molded disk is made of acrylic resin (refractive index 1.5) and a He-Ne laser (632
When writing at 8K), tracking is easiest when the depth of the guide groove is 790X. For writing through acrylic substrates, this corresponds to a depth of about 527X. This value requires extremely high-definition thin film coating technology compared to the coating technology already in use in the field of semiconductor manufacturing.

That is, Figure j@1 shows the steps k (a) to (C) of the conventional manufacturing method for master discs for sound discs and recording discs, Figure 0 is a longitudinal cross-sectional view of the obtained master disc, and Figure 2 is the obtained master disc. It is a Hirama diagram.

Figure (a) shows an example of a master disc for video or digital audio, and Figure (b) shows an example of a master disc for still image flaw information files, which has guide grooves for tracking. 1st
In Figure (a), (1) is a substrate, and (2) is an undercoat layer made of a metal thin film for improving the adhesion and adhesion between the positive resist layer (3) and the substrate. In the figure, the positive resist layer (3) is exposed to a focused laser beam (5) through an optical system (4) to sensitize it. Due to development, the unexposed portions of the positive resist layer (3) are insoluble and the resist remains, and the resist in the exposed areas is removed by the 3J agent, leaving a concavo-convex pattern (6) on the substrate (1).
occurs. (See Figure C) The positive resists that have been used in the production of conventional master discs for sound discs and recording discs have the following drawbacks.

(b) Sensitivity is low. (O) There are few types of materials. (c)
Poor adhesion to the substrate. ) There are more pinholes than negative types.

On the other hand, negative resists used in other fields have the following drawbacks. (b) Resolution is low.

[Purpose of the invention]

I: The present invention has been improved in view of the above drawbacks, and includes a dielectric layer, such as a negative resist film, which has excellent adhesion to the glass substrate and the positive resist film as an intermediate layer between the glass substrate and the positive resist film.
The present invention relates to a method for producing a master disc for a disc/recording disc in which the thickness of the positive resist layer is SOO~1500 Å, preferably 500~800 Å, and enables high-density recording without pinhole defects.

[Summary of the invention]

Before creating a master disc for a sound disc or recording disc, an adhesive layer is applied between the positive photoresist film coated on the surface of the Gaddess base and the base. is high. (in) Fewer pinholes. (c) Advantages of 0 etc. and positive type resists, which have many types of materials, such as (b) excellent resolution. (b) Good dimensional accuracy during development. These are used in combination to compensate for the drawbacks of using a positive resist alone.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. l/
FIG. 43 is a longitudinal sectional view showing a part of an embodiment of the method for manufacturing a master disc for a sound disc/recording disc according to the present invention. In FIG. 3, (t) and (a) show a substrate and a positive resist, and Qll is a negative resist layer consisting of a dielectric layer.

The dielectric layer used in the present invention is urethane-based.

In addition to chlorophrene-based, nitrile-butadiene-based, styrene-butadiene-based, and acrylic ester-based materials.

Epoxy 9 Trifluorochloroethylene with a low degree of polymerization.

Polyhydric alcohol, higher alcohol, thermoplastic polyester, vinylidene chloride, vinyl chloride, vinyl acetate, polyethylene, polyethylene glycol.

Ethylene and vinyl acetate 0 copolymer, butyral.

Acrylate, polyamide, shellac, rosin, photoresist, etc. can be used, and any material can be used as long as it has excellent adhesion to the substrate, positive cover, and resist film.

In order to further improve the adhesion between the base film (1) and the negative resist layer, a thin metal film (1◆ such as Cr) may be inserted. Next, the optical system (4) is used to The laser beam am>t is irradiated onto the positive deaf resist (3).

By developing with a positive developer, the resist layer in the exposed area is removed, and the resist layer in the unexposed area (a) remains to form an uneven pattern (al).

The photoresist forms the uneven pattern α$H)
Molecular weight increase due to polymerization, (b) molecular weight increase due to crosslinking,
31 polymerization, cross-linking polymerization in which cross-linking occurs simultaneously; or) molecular weight reduction.

〔Effect of the invention〕

In the method according to the present invention, the adhesion of the resist layer to the base is stronger than in the conventional example shown in glFiA, so there are no defects caused by local detachment of the resist during master formation, and there is no possibility of defects caused by local detachment of the resist during master formation. It is also extremely stable for copying stampers than lsK, so when we used a laser as a master to create a stamp, we were able to increase the 87N ratio by 60 times, and by using a plastic molded disk, we were able to improve it by a factor of 100.

As described above in detail, in the method for manufacturing a master disc for music discs and historical records according to the present invention, the photo-recording material coated on the base plate,
In order for the resist layer to adhere well to the substrate, there is a layer between the positive resist layer and the substrate that forms a highly uneven pattern.
A dielectric layer having excellent adhesion to both is provided, for example, a negative lid resist layer.

Therefore, a uniform resist layer with no defects or omissions can be obtained. Therefore, it is possible to obtain an extremely high 87N ratio during signal reproduction, whether it is on an original disc or on an acrylic disc after plastic molding.

[Brief explanation of the drawing]

Figure 1 shows the conventional manufacturing method for master discs for sound discs and recording discs.
(Jl) is a longitudinal cross-sectional view of a photosensitive layer with a resist layer provided on a substrate, (b) shows the process of exposing the photosensitive layer, and (C) shows the process of exposing the photosensitive layer.
is a vertical cross-sectional view of the profile of the photosensitive layer after the 3jl image, s
Figure 2 shows a plan view of the master disc for sound discs and recording discs.
A diagram showing the signal pits of a master disc for video discs and digital audio discs, (b) is a diagram showing guide grooves for tracking the master disc for a stationary 1 mm sofile, and FIG. A method of manufacturing a master disc for recording discs is shown, in which (a) is a vertical cross-sectional view of a photosensitive layer with a resist layer provided on a substrate, and (b) is a longitudinal cross-sectional view of the photosensitive layer, and (C) shows the process of exposing the photosensitive layer.
) is a diagram showing the profile of the photosensitive layer after construction. (1)...Base, (3)...Positive resist film, (
4)...Optical system, (5)...Laser beam, (6),
αη...Unexposed area, @side...Exposed area, H...Negative deaf resist film (ill electric layer) 3rd figure

Claims (1)

[Claims] (υ It is also possible to selectively remove a part of the IMIIiK-coated photoresist film by laser exposure 11 to record information, and to provide excellent adhesion between the photoresist film and the substrate. (2) The photoresist film that is selectively removed by laser exposure and development is a positive resist film, A method for manufacturing a master disc for a sound disc or recording disc according to claim 1, characterized in that the dielectric layer with excellent adhesiveness is made of a negative resist film to form a laminated structure. (3) On the substrate a first step of coating a negative resist on the negative resist; and a j12o step of coating a positive resist on the negative resist after baking the negative resist film;
A method for manufacturing a JI3 sound disk/recording master, which comprises exposing a resist film laminated on the substrate to laser light. (4) The thickness of the positive melon resist film is soo~1so
A method for manufacturing a master disc for a sound disc/record disc as described in the patent **'-Koman- section, characterized in that: oX.