JPH0482035A - Production of optical disk - Google Patents

Abstract

PURPOSE:To easily form a stamper in a short period of time by selectively forming projecting patterns on a metallic film to form the stamper and transferring the projecting patterns of the stamper to a blank substrate, then forming a light reflecting film and protective film on the blank substrate. CONSTITUTION:A photosetting type resin 12 consisting of 2P (photo-Polymer) having pregrooves is formed on the substrate 11 and a metallic film 13 is deposited and formed thereon. The substrate 11 is then irradiated with a laser beam, by which the projecting patterns 14 are formed on the metallic film 13. The stamper consisting of the glass substrate 11 having the metallic film 13 formed with the projecting patterns 14 is installed in a metallic mold and the mold is heated. A polycarbonate resin is installed on the metallic film 13 and is pressurized by a low pressure, by which the metallic patterns are transferred onto the resin surface. A light reflecting film 17 consisting of Al and Au and a resist film consisting of a UV curing resin are applied as a protective film 18 thereon. The optical disk is easily formed in a short period of time in this way.

Description

[Detailed Description of the Invention] [Summary] A method for manufacturing an optical disk that eliminates the need for applying a resist solution, exposing and developing a resist film formed by the coating, and plating a metal film on the resist film. The purpose of this method is to reduce the number of steps and easily form a stamper in a short period of time.The purpose of this method is to reduce the number of steps and form a stamper easily in a short time.After depositing a metal film that can undergo a phase change by heating on a substrate provided with a pre-group, The metal film is selectively irradiated with a light beam in a predetermined pattern, a convex pattern is selectively formed on the metal film to form a stamper, and the convex pattern of the stamper is transferred to a blank substrate. The blank substrate is peeled off from the stamper, and a light reflecting film and a protective film are formed on the blank substrate.

[Industrial application field]

The present invention relates to a method of manufacturing an optical disc.

An optical disc such as a CD or CD-ROyI is formed by forming a transparent plastic layer having a concavo-convex pattern on which information is recorded on the surface of a circular transparent substrate, and then providing a light-reflecting layer thereon.

[Conventional technology]

Conventionally, in order to form such an optical disk, the process shown in FIG. 2 (
As shown in a), a resist film 2 is placed on a transparent glass disk I.
A laser beam is selectively irradiated onto the resist film in a predetermined pattern to record a signal, and then exposed and developed to form a concavo-convex pattern on the surface of the resist film, which is used as recorded information.

Next, a metal thin film 3 such as nickel (Ni) or cobalt (Co) is deposited on the resist film having the uneven pattern, and a Ni metal electrolytic plating layer is formed using this thin film as an electrode. Peel it off and use it as a stamper. This stamper is then installed in a mold of an injection molding machine.

Then, as shown in FIG. 2(b), molten plastic resin 4 such as polycarbonate is injected into the mold described above to form a disk shape, and the unevenness information on the surface of the stamper is transferred.

Then, the surface of this plastic resin is coated with aluminum (A
f) Alternatively, a light reflecting film 5 made of gold (Au) or the like is formed by vapor deposition or the Svanta method. Then, after applying an ultraviolet curing resin such as a resist film as a protective film 6,
It hardens to form an optical disc.

[Problem to be solved by the invention]

However, the conventional method described above requires a number of manufacturing steps to form a stamper, such as applying a resist solution, exposing and developing the applied resist film, and depositing metal on the resist film, and plating. However, there are problems in that it takes a long time to manufacture the stamper and requires complicated management work such as managing the resist solution or the concentration of the plating solution.

The present invention solves the above-mentioned problems, eliminates the complicated steps such as resist solution coating, exposure, development, vapor deposition, and plating, and makes it possible to easily obtain an optical disk in a short time through simple steps. The purpose of the present invention is to provide a method for manufacturing such an optical disc.

[Means to solve the problem]

The method for manufacturing an optical disc of the present invention that achieves the above object includes:
After depositing a metal film that can undergo a phase change by heating on a substrate provided with pre-groups, a light beam is selectively irradiated onto the metal film in a predetermined pattern to selectively create a convex pattern on the metal film. After transferring the convex pattern of the stamper to a blank substrate, the blank substrate is peeled off from the stamper, and a light reflecting film and a protective film are formed on the blank substrate. Alternatively, a light reflecting film is formed on the blank substrate in advance, and the convex pattern of the stamper is transferred while heating the substrate. Further, the thickness of the metal film is in the range of 100 to 800 nm.

[For production]

Photocurable 2P with pre-groups on a glass substrate
(Photo-Polymer) resin is formed on the substrate, made of indium antimony (InSb), and S
When a thin alloy film containing 55 to 65 atomic % of bO on the joint side is formed and heated by selective irradiation with laser light, the heated region undergoes a phase change from a zinc blende crystal structure to a cubic crystal phase. At the same time, a convex pattern is formed in the heated region.

Such a convex alloy thin film pattern is formed in the heating region when the substrate on which the alloy thin film is deposited is flat. The present inventors have experimentally confirmed that the film is formed only when the film is deposited on a substrate provided with a group.

When the substrate provided with pre-groups is selectively irradiated with laser light in this manner, a heat retention region is formed on the substrate due to heating by the laser light, thereby forming a convex pattern in the irradiation region.

A stamper made of a glass substrate having a metal film on which this convex pattern is formed is placed in a mold, the cough mold is heated, a polycarbonate resin is placed on the metal film, and the resin is applied at low pressure. When pressed, a metal pattern is transferred to the resin surface. Then, if a light reflective film such as i or Au and a resist film made of ultraviolet curable resin are applied as a protective film on top of that, the complicated management of resist solution and the complicated process of plating a metal film on the resist film can be avoided. To easily form an optical disk in a short time without having to remove any material.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1(a), a 2P (Photo-PolylIl
er) is formed into a spiral shape by applying a resist solution and exposing and developing a predetermined pattern.

Next, as shown in FIG. 1(b), a metal film 13 made of an InSb alloy thin film containing 37 atomic % In and 63 atomic % Sb is deposited to a thickness of 460 nm by sputtering.

Next, the substrate 11 made of this glass disk was moved at a circumferential speed of 1.4
It rotates at m/sec, focuses a laser beam with a wavelength of 780 nm from a semiconductor laser light source with a lens (not shown), and
Intensity modulates the laser beam with a D format signal and
The metal film 13 made of an Sb alloy thin film was irradiated. The irradiation power of this semiconductor laser light source is 81 at the surface of the substrate made of a glass disk.

In this way, as shown in FIG.
A spiral convex pattern 14 is formed in the groove 15 of the metal film.

Next, the stamper made of the metal film having the convex pattern and the glass disk is placed in an embossing mold (not shown).
The mold is heated to 190°C, and a polycarbonate sheet with a flat surface is placed on the metal film for transferring the convex pattern of the metal film, as shown in FIG. 1(d). Install a blank board 16 made by
Apply a low pressure of about 30 g/cm" and pressurize for 30 seconds.

This pressure is much lower than that of conventional injection molding machines used to injection mold plastic resins, so the glass substrate will not be damaged and the equipment can be large and expensive. When this unnecessary pressure is removed, the convex pattern of the metal film is faithfully transferred onto the blank polycarbonate substrate. Next, this blank substrate is removed from the mold.

Next, as shown in FIG. 1(e), onto the surface of the blank substrate 16! A light reflecting film 17 is formed by depositing metal to a thickness of 20 Or+n+, and a protective film 18 is formed by applying an ultraviolet curing resin thereon. When the optical disc thus formed was placed in a CD player and music information was played back, the audio could be played back exactly like a normal CD disc.

Further, even when this embossing was repeated 500 times, the stamper made of the glass substrate and the metal film having a convex pattern was not damaged, and no defects were observed in the formed CD disc.

As another example, the same stamper and mold used in the previous example were used, and the blank substrate was a polycarbonate substrate on which a gold (Au) film had been vapor-deposited in advance to a thickness of 100 rv. , the substrate was preheated to 80
When the surface of the polycarbonate substrate on which the gold film was vapor-deposited was heated to 0.degree. C. and embossed, the convex pattern of the metal film of the stamper could be faithfully transferred, as in the above embodiment.

When the optical disc thus formed was placed in a CD player and music information was played back, the same music information as in the previous example could be faithfully played back.

Moreover, the number of embossing moldings was also possible over 500 times.

Furthermore, instead of recording music information, it was possible to create a so-called CD-ROM that recorded computer program information and could reproduce signals faithfully.

As a result of experiments, the inventors have found that the height of the convex portions of the convex pattern varies depending on the thickness of the alloy thin film, and that when the thickness of the alloy thin film changes from 1100 nm to 800 nm, the height of the convex portions increases. The height varies between 50 and 200 nm. In this case, when the thickness of the alloy thin film is 400 nm, the height of the convex part becomes 120 nm, and when the wavelength of the semiconductor laser beam for reproduction is 800 nm, the convex part pattern formed on the metal pattern is It has been found that the interference of the laser light of the above wavelength is maximum at the top of the groove and the surface of the groove of the metal film on which the convex pattern is formed, and reproduction can be performed with the highest reliability.

Furthermore, in the example, the proportions of In and Sb in the metal film 13 were set to 37 and 63 atomic percent, but the proportion of Sb in InSb was set to 5 atomic percent.
A similar effect was obtained when the content was varied from 5 to 65 atom%.

It has been found that a convex pattern due to phase change is not formed outside this range.

As described above, according to the method of the present invention, complicated steps such as exposure of a resist film, development process, plating process of a metal film, and concentration control of a plating liquid can be omitted during stamper production, and can be done easily in a short time. can form an optical disc.

〔Effect of the invention〕

As is clear from the above description, the present invention has the advantage that optical discs having various recorded information can be easily formed in a short time using a simple method.

[Brief explanation of drawings]

FIG. 1(a) to FIG. 1(e) are cross-sectional views of an embodiment of the optical disk manufacturing method of the present invention, and FIG. 2(a) and FIG. 2(b) are cross-sectional views of a conventional optical disk manufacturing method. It is a sectional view showing a manufacturing method. In the figure, 11 is a substrate, 12 is a photocurable resin, 13 is a metal film, and 14
is a convex pattern, 15 is a groove, 16 is a blank substrate, 17
18 indicates a light reflecting film, and 18 indicates a protective film. Figure 1 (÷ color 2) (d) 44: Production method of Moe, l run, 77 (f) 46 LA1rlde't2h%AaJ5 & non-T @°i
C2112 figure

Claims (1)

[Claims] [1] After depositing a metal film (13) that changes phase by heating on a substrate (11) provided with pregrooves, a light beam is selectively applied to the metal film in a predetermined pattern. irradiate to selectively form a convex pattern (14) on the metal film to form a stamper, and place the convex pattern (14) of the stamper on a blank substrate (1).
After transferring to 6), the blank substrate is peeled off from the stamper to obtain a blank substrate (1) to which the convex pattern of the metal film has been transferred.
6) A method for manufacturing an optical disc, comprising forming a light reflecting film (17) and a protective film (18). [2] A light reflective film (1) is coated on the blank substrate (16) in advance.
7), and transferring the convex pattern of the stamper onto the light reflective film forming surface of the blank substrate while heating the substrate. [3] The metal film (13) is made of InSb, and the proportion of Sb is in the range of 55 to 65 at%, and the metal film (13)
2. The method for manufacturing an optical disc according to claim 1, wherein the thickness of the optical disc is in the range of 100 to 800 nm.