JPH0963132A - Production of substrate for optical information recording medium and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable high-speed dry treatment by generating activated species such as excited species and ions of oxygen by electric discharge under atmospheric pressure, allowing them to react chemically with an org. material on the surface of a stamper and removing the org. material. SOLUTION: Gaseous helium and oxygen are fed from a gas feeder 5 into a metallic cover 2 and substd. for an atmosphere near an electrode 3 for causing electric discharge and a stamper 1. Electric discharge is caused between the electrode 3 and the stamper 1 by supplying high-frequency power from a high-frequency power source 4 to the electrode 3 to form an electric discharge part 7 and a UV-curing resin 8 remaining on the stamper 1 is removed by electric discharge treatment. In this case, various reactions by plasma such as dissociation, ionization and excitation of gas take place in the electric discharge part 7 and the remaining UV-curing resin 8 reacts with active seeds such as excited seeds and ions of oxygen and becomes CO, CO2 and steam, which are released from the stamper 1 and discharged through a duct 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method suitable for a substrate for an optical information recording medium for performing optical writing and reading by a laser and the like and a manufacturing apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, in an optical information recording medium such as an optical disk or an optical card, information is recorded by forming minute optically detectable pits on a track in a thin recording layer provided on a substrate. High-density recording can be performed. In such an optical information recording medium, it is necessary to scan a laser beam along a track when recording and reproducing information, and therefore, a substrate having a guide groove for tracking is generally used.

The guide groove and the substrate having the guide groove are manufactured by a compression molding method in which a softened plastic material is pressed by a stamper and then solidified, and a plastic material melted in a die in which the stamper is arranged. An injection molding method of injecting and solidifying a material and a 2P method of transferring a guide groove from a stamper using an ultraviolet curable resin are known, but the transfer property of the guide groove, the solvent resistance of the substrate and the optical property of the substrate are known. The 2P method is the most excellent in that distortion can be reduced. Further, the 2P method has a problem that the manufacturing time per substrate is long and is not suitable for mass production as compared with other methods, but has a great advantage that the capital investment is very small.

[0004]

However, the 2P method has the following problems. In the 2P method, first, an ultraviolet curable resin is applied on a substrate or a stamper, then the substrate and the stamper are attached to each other, and when the ultraviolet curable resin spreads over the entire surface of the substrate, ultraviolet rays are irradiated for a predetermined time from the transparent substrate side. Then, the ultraviolet curable resin is cured. Next, the substrate is separated from the stamper together with the ultraviolet curable resin to obtain a substrate having an uneven pattern. At the time of this peeling, a slight amount of the ultraviolet curable resin remains on the stamper. In particular, as shown in FIG. 1, the ultraviolet curable resin is likely to remain on the boundary between the outermost circumference and the innermost circumference of the spreading portion. Therefore, in order to improve the releasability between the stamper and the substrate, a method of treating the stamper with a release agent, a method of forming a film with good releasability, or an ultraviolet curable resin with good releasability is used. Although a method and the like have been studied, it is not possible to completely eliminate the residue of the ultraviolet curable resin, and there are problems in durability and stability. A wet method is generally known as a method for removing organic substances such as an ultraviolet curable resin, but a rinsing step for removing the cleaning agent after the cleaning step and a drying step for drying the stamper are required. However, the process becomes expensive and the processing time becomes long. Further, as a dry method, a method of irradiating a stamper with ozone or an ultraviolet ray has a problem that it has a low ability to remove an organic substance such as an ultraviolet curable resin and a treatment time becomes long. In recent years, as described in Japanese Patent Laid-Open No. 6-190269, an apparatus has been developed which treats a surface inexpensively and easily by generating an electric discharge under atmospheric pressure without using a vacuum system and a water system.

Therefore, an object of the present invention is to solve the above-mentioned problems and to remove the organic substances such as the ultraviolet curable resin remaining on the stamper in a shorter time than in the conventional case, and to provide a substrate for an optical information recording medium. It is to provide a method of manufacturing with high productivity and improved yield.

[0006]

A method of manufacturing a substrate for an optical information recording medium according to the present invention uses a stamper having a guide groove and / or an uneven pattern corresponding to information, and the uneven pattern of the stamper is formed on a substrate. In a method of manufacturing a substrate for an optical information recording medium by transferring and forming using an ultraviolet curable resin, a discharge is generated in a gas atmosphere containing at least oxygen under atmospheric pressure or a pressure in the vicinity thereof, and the discharge The method is characterized by including a step of chemically reacting the active species such as excitation and ions generated by the method and an organic substance on the stamper surface to remove the organic substance.

A discharge generating electrode is arranged in the vicinity of the stamper, and a high frequency voltage is applied to the discharge generating electrode to cause discharge in the space between the substrate and the discharge generating electrode. Is characterized by.

In addition, a high-frequency voltage is applied between the discharge-generating electrode and the counter electrode to cause discharge, and at least oxygen gas is passed through the discharge space to generate excitation and active species such as ions. It is characterized in that a gas flow containing active species is sprayed from the gas outlet to the stamper that is not exposed to the discharge.

Further, the discharge generating electrode when the stamper is exposed to a discharge, or the gas blowout port when a gas flow is blown without being exposed to the discharge is made larger than the size of the substrate.

It is characterized in that the stamper is cooled or heated.

The apparatus for manufacturing a substrate for an optical information recording medium according to the present invention comprises a discharge generating electrode, a means for applying a high frequency voltage to the discharge generating electrode under atmospheric pressure or a pressure in the vicinity thereof, and at least oxygen. At least a means for introducing a gas containing a gas near the discharge generating electrode, and a means for exhausting a gas such as a gas generated by the discharge or a reaction gas with an organic substance on the stamper surface. .

Further, it is characterized in that at least means for cooling or heating the stamper is provided.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 2 is a schematic view showing Embodiment 1 of the present invention.

The discharge process is performed as follows. The process is carried out under atmospheric pressure, so the atmosphere is air. A discharge generating electrode 3 electrically floated by an insulator 6 is mounted in a metal cover 2 installed on the ground. Helium gas and oxygen are caused to flow from the gas supply device 5 into the metal cover 2 to replace the atmosphere near the discharge generating electrode 3 and the stamper 1 with the helium gas and oxygen. Next, when high-frequency power is applied from the high-frequency power source 4 to the discharge-generating electrode 3, the discharge-generating electrode 3 is discharged between the stamper 1 to form the discharge portion 7. Here, helium gas was used as the gas for causing the discharge, but argon gas may be used. Further, the metal cover 2 is not always necessary as a condition for causing discharge. Furthermore, the metal cover 2 does not have to be metal, and may be ceramic.

First, a predetermined amount of ultraviolet curable resin is applied to a polycarbonate substrate. Although polycarbonate is used as the substrate, amorphous polyolefin, acrylic, polyester, epoxy, glass, or the like may be used. As the ultraviolet curable resin, a prepolymer, an oligomer, a monomer or the like having an unsaturated bond in the molecule can be used. For example, unsaturated polyesters, acrylates such as epoxy acrylate, urethane acrylate, and polyether acrylate, epoxy methacrylate, urethane methacrylate, polyether methacrylate,
One or more methacrylates such as polyester methacrylate and a photopolymerizable monomer having an unsaturated bond in the molecule, for example, dicyclopentenyl acrylate, 1,3-butanediol acrylate, polyethylene glycol diacrylate, pentaerythritol triacrylate. A mixture of functional monomers such as
Furthermore, halogenated acetophenones as a polymerization initiator,
Benzophenone, benzoin, benzoin ether, Michler's ketone, benzyl, benzyl dimethyl ketal,
A radical-generating compound such as thioxanthone is used, and any compound that can be easily peeled off from the stamper in the cured state and has good matching with the recording layer may be used. Next, the substrate and the stamper 1 are attached to each other, and when the ultraviolet curable resin spreads over the entire surface of the substrate, ultraviolet rays are irradiated for a predetermined time from the transparent substrate side to cure the ultraviolet curable resin. Next, the substrate is separated from the stamper 1 together with the ultraviolet curable resin to obtain a substrate having an uneven pattern. Next, the ultraviolet curable resin 8 remaining on the stamper 1 is removed by the discharge treatment. Specifically, in the discharge part 7, various reactions such as gas dissociation, ionization, and excitation due to plasma exist, and the ultraviolet curable resin 8 remaining on the surface of the stamper 1 is activated by oxygen ions, excited species, and the like. It reacts with the seeds to form carbon monoxide, carbon dioxide and water vapor, which is separated from the stamper 1 and exhausted through the duct 9.

As a result, the UV curable resin 8 remaining on the surface of the stamper 1 was removed very easily.
It should be noted that this discharge treatment need not be performed every time one substrate is prepared, and may be performed according to the degree of contamination on the surface of the stamper 1.

COMPARATIVE EXAMPLE 1 Only helium gas was used as the discharge gas, and other steps were carried out in the same manner as in Example 1 to try to remove the contamination on the surface of the stamper 1, but there was almost no change and the contamination was removed. I couldn't.

(Embodiment 2) FIG. 3 is a schematic diagram showing Embodiment 2 of the present invention.

The discharge process is performed as follows. The metal cover 2 of the first embodiment is extended to the vicinity of the tip of the discharge generating electrode 3, and the counter electrode 10 for generating discharge is provided.
And Similarly to the above, when helium gas and oxygen are caused to flow from the gas supply device 5 into the metal cover 2 to replace the inside with helium gas and oxygen, and a high frequency voltage is applied from the high frequency power source 4 to the discharge generating electrode 3. A discharge is generated between the tip of the discharge generating electrode 3 and the counter electrode 10.
In the discharge part 7, a part of the oxygen gas becomes active species such as ions and excited species, and from the gas outlet 11 arbitrarily determined by the shape of the counter electrode 10 which is the tip of the metal cover 2, The reactive gas stream 12 is blown out together with the helium gas. From the gas outlet 11 to 3 to
Install the stamper 1 at a distance of 5 mm.

First, a predetermined amount of ultraviolet curable resin is applied to a polycarbonate substrate. Although polycarbonate is used as the substrate, amorphous polyolefin, acrylic, polyester, epoxy, glass, or the like may be used. Next, the substrate and the stamper 1 are attached to each other, and when the ultraviolet curable resin spreads over the entire surface of the substrate, ultraviolet rays are irradiated for a predetermined time from the transparent substrate side to cure the ultraviolet curable resin.
Next, the substrate and the stamper 1 together with the ultraviolet curable resin
Then, it is peeled off to obtain a substrate having an uneven pattern. Next, the ultraviolet curable resin 8 remaining on the stamper 1 is removed by the discharge treatment. Specifically, active species such as oxygen ions and excited species in the reactive gas stream 12 blown out from the gas outlet 11 and the UV curable resin 8 remaining on the surface of the stamper 1 react to react with carbon monoxide. Becomes carbon dioxide and water vapor, and is separated from the stamper 1 and exhausted through the duct 9.

As a result, the UV curable resin 8 remaining on the surface of the stamper 1 was removed very easily.
It should be noted that this discharge treatment need not be performed every time one substrate is prepared, and may be performed according to the degree of contamination on the surface of the stamper 1.

In Embodiments 1 and 2, the size of the discharge generating electrode 3 when the stamper 1 is exposed to a discharge or the size of the gas blowout port 9 when a gas flow is blown without being exposed to the discharge is The larger the size, the better. If the size is larger than the substrate, the processing can be performed in a batch, and the processing can be performed in a short time, and the processing can be performed with the stamper 1 fixed, so that the load on the apparatus can be reduced.

(Embodiment 3) FIG. 4 is a schematic diagram showing Embodiment 3 of the present invention.

A heating / cooling device 13 was used as a holder for the stamper 1. The stamper 1 is heated to 50 to 100 degrees depending on the conditions by electric discharge or radiant heat of the electric discharge generating electrode 3. When the stamper 1 is easily warped by heat, such as nickel, aluminum, or plastic, the stamper 1 can be processed while being cooled.

If the stamper 1 is stable against heat such as glass or silicon, it should be heated in reverse. Heat accelerates the reaction because it is a process using a chemical reaction. In the experiment by the present inventor, 15
At 0 degree, the processing speed was more than 3 times faster than at room temperature.

[0027]

As is apparent from the above description, according to the present invention, active species such as oxygen ions and excited species are generated by discharging at atmospheric pressure, and chemically react with them on the stamper surface. Since this is a method of removing the organic matter, therefore, not only an aqueous system is not required and a high-speed dry treatment is possible, but it is also simple and the apparatus cost is low.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a contaminated stamper of the present invention.

FIG. 2 is a schematic diagram showing Embodiment 1 of the present invention.

FIG. 3 is a schematic diagram showing Embodiment 2 of the present invention.

FIG. 4 is a schematic diagram showing Embodiment 3 of the present invention.

[Explanation of symbols]

 1 Stamper 2 Metal Cover 3 Discharge Generation Electrode 4 High Frequency Power Supply 5 Gas Supply Device 6 Insulator 7 Discharge Section 8 Remaining UV Curing Resin 9 Duct 10 Counter Electrode 11 Gas Blowout 12 Reactive Gas Flow 13 Heating / Cooling Device

Claims (7)

[Claims] 1. A substrate for an optical information recording medium is formed by using a stamper having a guide groove and / or a concave / convex pattern corresponding to information, and transferring the concave / convex pattern of the stamper onto the substrate by using an ultraviolet curable resin. In the method for producing, under atmospheric pressure, or under pressure in the vicinity thereof, a discharge is generated in a gas atmosphere containing at least oxygen, and excitation generated by the discharge, active species such as ions and an organic substance on the stamper surface. A method for producing a substrate for an optical information recording medium, which comprises a step of chemically reacting with the organic substance to remove the organic substance. 2. A discharge generating electrode is disposed in the vicinity of the stamper, and a high frequency voltage is applied to the discharge generating electrode to cause discharge in the space between the substrate and the discharge generating electrode. The method for manufacturing a substrate for an optical information recording medium according to claim 1. 3. A high-frequency voltage is applied between the discharge-generating electrode and the counter electrode to cause discharge, and at least oxygen gas is passed through the discharge space to generate excitation, active species such as ions, and the oxygen activity. 2. The method for manufacturing a substrate for an optical information recording medium according to claim 1, wherein a gas flow containing seeds is blown onto the stamper that is not exposed to the discharge from a gas outlet. 4. The electrode for discharge generation when the stamper is exposed to a discharge, or the gas outlet when a gas flow is blown without being exposed to the discharge, is larger than the size of the substrate. A method for manufacturing a substrate for an optical information recording medium as described above. 5. The method for manufacturing a substrate for an optical information recording medium according to claim 2, wherein the stamper is cooled or heated. 6. The discharge generating electrode, a means for applying a high frequency voltage to the discharge generating electrode, and a gas containing at least oxygen are introduced near the discharge generating electrode under atmospheric pressure or a pressure in the vicinity thereof. An apparatus for manufacturing a substrate for an optical information recording medium, comprising at least a means and a means for exhausting a gas such as a gas generated by electric discharge and a reaction gas with an organic substance on the stamper surface. 7. The apparatus for manufacturing a substrate for an optical information recording medium according to claim 6, further comprising at least a means for cooling or heating the stamper.