JPS61188757A - Manufacture of optical recording body - Google Patents

Abstract

PURPOSE:To simplify a manufacturing process by photo-etching the light reflecting metal layer on the substrate to form information pits. CONSTITUTION:A substrate 1 is coated with a light reflecting metal layer 2 and further with a photo-resist layer 3. Then, the said layers are subjected to exposure through pattern 4, and developed to form pits 5. Next, photo-resist in areas other than pits 5 are desolved and removed, leaving the light reflecting metal layer with pits 5 formed on the optical recording body 10. The substrate 1 should preferably have a thickness of 300mu-1.5mm.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an optical recording medium by forming optically readable information pits in advance by a simple method.

Conventional technology A heat mode recording material has been proposed in which the recording layer of a recording material is irradiated with an energy beam such as a laser beam in a circular pattern to cause a state change in a part of the recording layer for recording. There is.

For example, a recording material is created by forming a metal thin film layer of tellurium, bismuth, etc. on a base material, and by irradiating a spot of recording light such as a laser beam onto the metal thin film layer, the metal in this part is evaporated and removed. Alternatively, information is written by melting and moving to form pits.

However, in this type of recording material, in order to read out the recorded information smoothly, it is necessary to write tigers and kings, which correspond to guide grooves for the readout light, and breformatting to specify the pits to be read. be.

However, spot irradiation with a laser beam as a means of writing these tracking and breformatting requires advanced laser control technology, and the pit formation process is complicated, so it is not necessarily cheap from a cost perspective. do not have.

In addition, as mentioned above, in addition to the type of recording material that records and reads using a laser beam, etc. (DRAW type), there are also read-only type (ROM type) recorded materials, such as digital audio discs and digital video discs. etc. are in practical use. Such I'LOM-type recorded materials are usually reproduced by the press method, but when producing the press master plate, it is necessary to spot-expose the photoresist with a radar beam to create a concavo-convex pattern, and the use of a laser is necessary. The above problems still remain.

Problems to be Solved by the Invention Therefore, the problem to be solved by the present invention is to solve the problems in the use of a laser beam, which are unresolved in both DRAW type recording materials and ROM type recording materials. An object of the present invention is to provide a method for manufacturing an optical recording medium, which solves the above problems, has a simple manufacturing process, and enables mass production and cost reduction.

Means for Solving the Problems The present invention attempts to form information pits using a photoetching method.The present invention involves forming a light-reflecting metal thin film layer on a base material, and then forming a light-reflecting metal thin film layer on a base material. The gist of this invention is a method for manufacturing an optical recording medium, which is characterized in that information pits are formed by photo-etching a thin metal film layer.

Figures 1 to 4 are from Zero Invention - Invention 1. FIG.
A light-reflective metal thin film layer 2 is formed thereon, and a photoresist 3 is further formed thereon (FIG. 1). Next, exposure is carried out through the pattern 4 (Fig. 2), and development is performed to form pits 5 (Fig. 3). Thereafter, the photoresist in the non-pit portions is dissolved and removed, thereby forming the photoresist on the base material 1. , an optical recording medium 10 on which a light reflective metal thin film layer 2 having pits 5 is formed is obtained.

As the base material 1, various materials can be used, such as glass, ceramics, plastic, resin, etc. Plastics include polymethyl methacrylate, polycarbonate, polyethylene, polypropylene, polystyrene, , polyvinyl chloride, cellulose triacetate, polyvinyl fluoride, polysulfone, polyethersulfone, polyetherimide, polymethylpentene, etc. These include glass, ceramics, and plastics.

There is no problem in laminating two or more types of resins with each other, or with plasti and resins.

The base material 1 may be transparent, semi-transparent, or opaque when reading is performed from the light-reflective metal thin film layer 2 side, but when reading is performed from the base material side, it must be transparent to a degree that does not interfere with reading. Requires.

The thickness of the base material 1 is approximately 50 μm to 3N,
When reading from the base material side, as long as a decrease in light transmittance does not interfere with the readout, increasing the thickness will avoid read errors due to the influence of dust, etc. adhering to the base material. Taking into consideration, 300μm ~ 1.5M
degree is preferred.

The light-reflective metal thin film layer 2 is formed using a metal or an alloy as described below by means such as vapor deposition, sputtering, CVD, ion blasting, or molecular beam deposition.

As for metals, ■Metals with excellent light reflectivity, such as kl,
The first examples include Ni, Ag, Au, etc., or alloys mainly composed of these materials. When metals or alloys belonging to this group are used, the resulting optical recording medium has a high optical contrast between pit portions and non-pit portions, and is easy to read.

Alternatively, the metal 'C is Te, which is a melting point metal,
Zn, Pb, Cd+Bi, Sn+Se, In,
Metals such as Ga and Rh or alloys containing these as main components can also be used, and examples of preferable alloys include it and Te.
-Se, Te-8e-Pb, Te-Pb, Te
Examples include -8n-8,5n-Cu+Te-Cu-Pb, and Te-C containing 5 to 40 atoms of Cu.
u alloy) Te-C containing 5 to 40 atoms of Cu and Cu with 1 to 50 atoms of pb
u-Pb alloy (1) When the wavelength of the laser beam for reading is set to 6501 m or more, the optical contrast between the pit portion and the non-pit portion is high, and reading is easy.

Alternatively, examples of metals include Te oxide and s, which undergo a phase transition and change their light reflectance when irradiated with a laser beam or the like.
b oxide, Mo oxide, Ge oxide,
Compounds such as can also be used.

In addition, if the above metal and organic compound are combined with one inorganic acid,
ToO compound TatoL +i Te CHa, Te-C
82, Te-styrene, 5n-Bo2% Ges-8
Thin films such as n, 5nS-8 or SiO2/
Multilayer films such as T i /S i O2/Al can also be used as reflective metal films.

Furthermore, magneto-optical recording materials such as Gd Co and Tb Co
, GdFe + DyFe, GdTbFe, GdF
eB1, TbDyFe.

MnCuB1 or the like may also be used as the reflective metal thin film.

It is also possible to use a combination of various types of reflective metal thin films as described above.

The thickness of the light reflective metal thin film layer 2 is preferably 200 to 1000X.

In addition, multilayer films of metals or alloys as shown above,
For example, a multilayer film of an In film and a Te film can also be used as the light reflective metal thin film layer.

After forming a light-reflective metal thin film layer 2 on a substrate 1, photo-etching is performed on the light-reflective metal thin film layer 2 to form information bits.

The photoetching process typically involves successive steps of photoresist formation, pattern exposure, development, and removal of remaining photoresist.

Commercially available photoresists can be used; for example, negative photoresists include E and Ko.
KPR, KOR, Hunt Chemical made by dak
WAY COA, THR, FS box manufactured by Fuji Pharmaceutical,
TPR%0MR11N0NCI'LO manufactured by Tokyo Ohka Kogyo
5hi for N etc. or positive type photoresist
AZ-13Q Q, Hunt Chemi made by play
WAY C0AT HRP made by Cal, 0FPR made by Tokyo Ohka Kogyo.

Examples include Fi, KMPR1 manufactured by Kodak; dry films such as RISTON manufactured by Dupon't; SERITONg manufactured by Oguchi Kako; and dichromic acid photosensitive solutions such as egg white, casein, griyu, PVA, Nera, and li.

These photoresists can be coated using known coating methods, such as the pouring method, Wheeler method, spinner method, dipping method, roller coating method, spray method, electrostatic spray method, etc., or, in the case of dry films, by heat-pressing method. The photoresist thickness after application is usually 0.5 to 5.0 μm.

The photoresist 3 is usually subjected to pattern exposure after passing through a heating process called baking. Pattern exposure is conveniently carried out by irradiating ultraviolet rays, etc. through a pattern on photographic film or a metal mask, but there are other methods such as irradiating electron beams through a metal mask and using electron beams. A method of directly exposing the pattern by scanning without passing through the pattern may also be used. It is also possible. In this case, more accurate reproduction is possible than in the case of forming irregularities by producing a press mold master.

After pattern exposure, development is performed using a specified developer,
Bits (holes) 5 are formed in the light reflective metal thin film layer 2. In Figures 2 to 4, a positive type photoresist is assumed, and the photoresist in the portion corresponding to the transparent part of the pattern is broken down and removed by light, but as a negative type photoresist, Similar pits can be formed by changing the pattern even if a mold is used.

At the stage where the pits 5 are formed, the photoresist 3 usually remains on the remaining light-reflective metal thin film layer 2 (Fig. 3), so next, the photoresist is dissolved using a solvent that dissolves the photoresist. This is removed to obtain an optical recording medium 10 as shown in FIG.

Although the optical recording medium 10 obtained by the method of the present invention can be used as it is, it is most preferable to use it as follows.

How to use As shown in FIG. 5, optical recording is performed on a suitable substrate 11 designed for various uses by attaching the optical recording medium 10 to another substrate 11 via an adhesive or adhesive 12. 13 can be formed. In this case, the optical recording medium 1
If the side with the light reflective metal thin film layer 2 (see FIG. 4) of 0 is attached to the substrate side, the base material 1 of the optical recording medium 10 will be on the front side, so the light reflective metal having the bits 5 will be attached. It can serve to protect the thin film layer 2.

As shown in FIG. 5, when the optical recording medium 10 is attached to the substrate 11 via an adhesive or pressure-sensitive adhesive 12, the adhesive or adhesive 12 is applied to either or both of the optical recording medium 10 and the substrate 11. Although it can be applied to the optical recording medium 1
If the adhesive is applied to the 0 side in advance by coating or the like, there is an advantage that the adhesive or pressure-sensitive adhesive can be applied only to the necessary area when forming the optical recording section 13 partially on the base 11 as illustrated in FIG. be.

In addition to the structure shown in FIG. 5, the structure for adhering to the substrate 11 is as shown in FIG. Alternatively, as shown in FIG. 4, a concave structure may be provided, and a protective layer 13 made of a thin plastic film may be laminated on the front and back sides to be integrated.

In the above explanation regarding FIGS. 5 to 7, the explanation was centered on the optical recording material for adhesion in which an adhesive or pressure-sensitive adhesive is applied to the optical recording material, but the optical recording material for adhesion is further laminated with a releasable note. It may also be used as an optical recording medium for transfer. FIG. 8 shows an example of an optical recording medium for transfer, in which a release layer 15 is provided on one side of a sheet base material 14.
, an optical recording medium 10, and an adhesive 12 are laminated in this order. In this example, layers 15, 10 and 12, including the release layer.
Although the transfer layer 16 is used as the transfer layer 16, the release layer 15 may be peeled off between the release layer 15 and the optical recording medium, or the release layer 15 may be omitted. In addition, in the case of an optical recording medium for transfer as shown in FIG. 8, the transfer layer is divided into the required shape by punching from the adhesive side to the bottom surface of the sheet base material 14, or unnecessary portions are further removed. It is also possible to supply the optical recording medium in a predetermined shape to a predetermined position on the substrate 11 by supplying the substrate 11 continuously. After the transfer, a protective layer may be further provided if necessary.

The structures shown in Figures 5 to 7 are mainly cards (
It is used for ID cards such as cash cards, credit cards, credit cards, etc., but when used as a card, it may be used in conjunction with other means, such as magnetic layers, holograms, etc.
Imprint (emboss), face photo, engraving, signature, I
Examples include C memory, barcodes, and general printing.

The optical recording medium obtained by the method of the present invention can be used alone or by being attached to another substrate as a recording medium such as a card.

It is also possible to make additional records in the blank areas where there are no records using a laser beam or the like, and since the records previously obtained by photo-etching and the additional records are on the same surface, they are easy to read. The shape of the optical recording section itself can also be created by photoetching.

Effects and Effects According to the method of the present invention, an optical recording medium can be manufactured more easily and efficiently than a method using photoetching, which includes steps such as pattern exposure and development.

, □ Example Transparent polycarbonate resin film (thickness 400 μm
) was pretreated by first Freon cleaning and then heat treatment at a temperature of 80° C. for 30 minutes, and then aluminum was vacuum deposited on one side of the film to form an aluminum layer with a thickness of jOoμm.

Next, a photoresist (manufactured by Fuji Hunt Electronics Technology Co., Ltd., WAYCOA) was applied to the surface of the aluminum layer.
T■ HPR204) was coated using a roll coater so that the dry thickness was 1-1, and prebaked at a temperature of 100°C for 20 minutes to obtain a photosensitive layer.

An exposure mask prepared by writing information bits using an electron beam lithography device was used, and this mask was brought into close contact with the above photosensitive layer, and pattern exposure was carried out by irradiating ultraviolet rays from above the mask.

After exposure, the photoresist in the exposed area is dissolved and removed by immersion in a developer (LSI developer, manufactured by Fuji Hunt Electronics Technology).
Post-baking for 0 minutes, and then applying a corrosive solution (phosphoric acid 1
6 parts, 2 parts acetic acid, 1 part nitric acid, and 1 part water. The aluminum layer in the exposed area was corroded and removed by dipping for 3 minutes in a liquid (all parts indicate capacitance) to form a light-reflective metal thin film layer patterned with information bits.

On the other hand, a white rigid polyvinyl chloride resin film is cut into a predetermined size in the shape of a bank card, the front side is printed with the desired pattern, and the back side is provided with a magnetic stripe using a transfer method. Then, the polycarbonate resin film having the light-reflective metal thin film layer was laminated with an acrylic resin heat-sensitive adhesive so that the metal thin film layer and the card base faced each other, and heated with a hot roll at a surface temperature of 110°C. This was then crimped to make an optical recording card.

[Brief explanation of the drawing]

FIGS. 1 to 4 are all cross-sectional views showing the method of the present invention, and FIGS. 5 to 8 are all cross-sectional views showing examples of use of the optical recording medium obtained by the method of the present invention. . 1...Base material 2...Light reflective metal thin film layer 3...
...Photoresist 4...Pattern 5...Bit 10...Optical recording medium 11...・Base (card base) 12...
······glue

Claims (1)

[Claims] (1) A method for producing an optical recording medium, which comprises forming a light-reflecting metal thin film layer on a base material, and then photo-etching the light-reflecting metal thin film layer to form information pits.