KR20060053490A - Read only information storage medium and method for manufacturing the same - Google Patents

Abstract

Disclosed are a read-only information storage medium and a method of manufacturing the information storage medium.

The disclosed method of manufacturing a read-only information storage medium includes coating a photoreactive layer on a substrate; Exposing the photoreactive layer through a mask on which a data pattern is formed to form a reproduction-only mark; And applying a reflective layer and a protective layer on the photoreactive layer.

The manufacturing process of the information storage medium according to the present invention can be manufactured very simply by completing the storage medium only through the exposure process without developing, plating, and molding, thereby significantly reducing the production cost.

Description

Read only information storage medium and method for manufacturing the information storage medium

1A is a schematic cross-sectional view of a conventional read-only information storage medium.

1B is a block diagram of a manufacturing process of a conventional read-only information storage medium.

2A and 2B illustrate a manufacturing process of a read-only information storage medium according to the present invention.

3 is a block diagram illustrating a manufacturing process of a read-only information storage medium according to the present invention.

<Description of main part of drawing>

20 ... substrate, 22 ... photoreactive layer

25 ... mask, 25 ... reflective layer

27 ... protective layer, m ... mark for exclusive use of reproduction

The present invention relates to an information storage medium and a method for manufacturing the same, and more particularly, a reproduction-only information storage medium that simplifies the manufacturing process and reduces noise by forming a mark using a photoreactive material and recording information without pits. The manufacturing method is related.

In general, an information storage medium is widely used as an information recording medium of an optical pickup apparatus that records / reproduces information in a non-contact manner. An optical disk, which is a type of information storage medium, is a compact disk (CD) or a digital disk according to an information recording capacity. It is divided into a digital versatile disk (DVD). In addition, optical discs capable of recording, erasing and reproducing include 650MB CD-R, CD-RW, 4.7GB DVD + RW, and the like. Furthermore, HD-DVDs with a recording capacity of 20GB or more are being developed.

As described above, the information storage medium is being developed in the direction of increasing the recording capacity. As a method of increasing the recording capacity, there is typically a method of shortening the wavelength of the recording light source and increasing the numerical aperture of the objective lens. In addition, there is a method of constituting a plurality of recording layers.

On the other hand, pits or grooves are formed on the substrate in any kind of information storage medium. As another method of increasing the recording capacity, there may be a method of reducing the pit size or the track pitch of the groove.

The following shows the capacity, pit size, and track pitch of an information storage medium by generation.

1st generation 2nd generation 3rd generation Standard name  CD  DVD BD Volume 650 MB 4.7 GB 25 GB Laser wavelength 780 nm 650 nm 405 nm Objective lens opening 0.45 0.6 0.85 Minimum Feet Size 0.83 μm 0.40㎛ 0.16 μm Track pitch 1.6 μm 0.74 μm 0.32 μm

As shown in Table 1, the larger the recording capacity is, the smaller the recording pit size and track pitch are, and techniques for reducing the pit size and track pitch are being developed. Here, BD stands for Blu-ray Disc.

1A is a schematic cross-sectional view of a read-only information storage medium having pits formed therein. A recording layer 12 having a pit p formed on the substrate 10 is provided, and a reflective layer 13 and a protective layer 14 are provided thereon.

1B is a block diagram illustrating a manufacturing process of a conventional information storage medium. The information storage medium manufacturing process can be roughly divided into a mastering process and a disc making process. The mastering process is a process for making a stamper for ejecting a substrate, coating a photoresist on a glass disc (S10), and irradiating and exposing the photoresist on a photoresist according to a signal corresponding to a mark to be recorded on the laser beam ( S12). Subsequently, the original plate coated with the photoresist is developed to produce a recorded master (S14), an electrode layer is formed on the glass master by Ni sputtering (S16), and then plated (S18). The recording master is formed with a pit shape and a groove shape.

Next, the plating layer is separated from the recording master to form a stamper (S20). The stamper inverts the pit shape and groove shape formed in the recording master.

The substrate is injection molded using the stamper (S22). Then, the recording film is laminated on the injection molded substrate by sputtering (S24), and the cover layer is laminated on the recording film (S26). Through this process, a disc is produced (S28).

In the conventional manufacturing process of the read-only information storage medium, there are complicated problems such as development and plating steps.

One of the most important factors for determining the pit size and track pitch in the above manufacturing process may be referred to as a recording process (S12) by laser beam irradiation. In order to reduce the pit size or track pitch to increase the recording capacity, the spot size of the laser beam must be made smaller. By reducing the laser wavelength and increasing the numerical aperture NA, the spot size of the laser beam can be reduced.

However, there is a limit to lasers for generations of higher recording capacity and higher capacity for discs of the later generations of Blu-ray Disc (BD). Therefore, a method of using an electron beam having a short wavelength instead of a laser beam has been newly researched and developed. As such, new attempts are being made to satisfy higher density and higher capacity of recording capacity. However, in order to use the electron beam, expensive equipment is required, and the stabilization of the electron beam is still insufficient.

In addition, as the information storage medium becomes denser, the width of the pit becomes very short, and a pit longer than the width of the pit needs to be formed. It is difficult, and therefore, miniaturization of the pit is impossible. In addition, when deformation occurs in the shape of the pit during pit molding, noise may occur, resulting in a poor data reproduction signal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an information storage medium recording reproduction-only information without pits and a manufacturing process thereof.

In order to achieve the above object, a method of manufacturing a read-only information storage medium according to the present invention,

Coating a photoreaction layer on the substrate; Exposing the photoreactive layer through a mask on which a data pattern is formed to form a reproduction-only mark; And applying a reflective layer and a protective layer on the photoreactive layer.

The photoreactive layer is formed of a photochromic material or a photoresist material.

The photoreaction layer is characterized in that formed of WO3.

The data pattern is preferably recorded in the mask by an e-beam lithography method.

In the read-only information storage medium according to the present invention,

Board; A photoreaction layer provided on the substrate and having a mark dedicated for reproduction by exposure; And a reflective layer laminated on the photoreactive layer.

Hereinafter, a reproduction-only information storage medium and a method of manufacturing the same according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the method of manufacturing a storage medium for exclusive use according to the present invention, referring to FIG. 2A, a photoreaction layer 22 is coated on a substrate 20 and exposed using a mask 25. When the photoreactive layer 22 is exposed by irradiating light L from the upper portion of the mask 25, the photoreaction layer 22 generates a photoreaction according to a pattern formed on the mask 25 so that the mark m is formed. Is formed.

The substrate 20 is formed of any one material selected from polycarbonate, polymethylmethacrylate (PMMA), amorphous polyolefin (APO), and glass materials.

The photoreactive layer 22 is made of photochromic material or photoresist material. Photoreaction layer 22 may be comprised of WO3, for example. In addition, the photoreaction layer 22 may be formed by heat-treating a solution obtained by dispersing a photochromic material in a water-soluble resin at a temperature of 80-100 ° C. As the water-soluble resin, polyvinyl alcohol is used as a main component or methyl cellulose, polyvinyl pyrrolidone, or the like is used.

The mask 25 is used as a recording disc and is produced by an e-beam lithography method. Since the recording mark m is simultaneously formed on the photoreaction layer 22 through the mask 25, the manufacturing process is very simple. In the conventional process, the recording process is very simple compared to the recording by irradiation of the laser beam. The recorded data is reproduced by the difference in reflectance between the mark m formed on the photoreactive layer 22 exposed through the mask 25 and the portion where other marks are not formed.

In addition, a reflective layer 25 and a protective layer 27 are coated on the photoreactive layer 22.

As described above, the reproduction-only information storage medium according to the present invention is simply completed without developing, plating and molding.

Referring to FIG. 3, a method of manufacturing an information storage medium according to the present invention includes preparing a substrate (S100), coating a photoreactive layer on the substrate (S102), and forming the photoreactive layer through a mask on which an information pattern is formed. It exposes and forms a mark for reproduction only (S104). Then, the reflective layer and the protective layer is coated on the photoreactive layer (S106).

The information storage medium according to the present invention manufactured by the above manufacturing process is characterized in that a mark dedicated for reproduction without pits is formed. In the case of recording / reproducing data by using super resolution for high capacity, if the data is recorded by the pit, it is difficult to form the pit and the pit shape is distorted. Thus, noise is generated. Formation solved this problem.

As described above, the information storage medium according to the present invention forms a reproduction-only mark without pits to improve noise, and the manufacturing process of the information storage medium according to the present invention is stored only through an exposure process without undergoing development, plating, and molding. Completion of the medium makes it very simple to manufacture, thereby significantly reducing production costs.

Claims (5)

A method of manufacturing a read-only information storage medium, Coating a photoreaction layer on the substrate; Exposing the photoreactive layer through a mask on which a data pattern is formed to form a reproduction-only mark; And applying a reflective layer and a protective layer on the photoreaction layer. The method of claim 1, And the photoreactive layer is formed of photochromic material or photoresist material. The method of claim 2, The photoreaction layer is a manufacturing method, characterized in that formed of WO3. The method of claim 1, And the data pattern is recorded in the mask by an e-beam lithography method. In the read-only information storage medium, Board; A photoreaction layer provided on the substrate and having a mark dedicated for reproduction by exposure; And a reflective layer laminated on the photoreactive layer.

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