JPH0371823A - Apparatus for manufacturing base sheet for photorecording medium - Google Patents

Abstract

PURPOSE:To improve application efficiency of a stamper and to make exchang ing operation of the stamper easy by fixing a Ni-stamper wherein specified recessed and projected parts are formed on a die set and using a stamper roll on the main body of which the die set is removably fixed. CONSTITUTION:A die set 5 prepd. by a material with a relatively high rigidity and a large heat transfer coefficient is removably fitted and fixed on a main body 3 of a roll by means of a fixing bolt 7. To keep roundness, this die set 5 is formed either by bending uniformly a metal sheet material with a relatively thin thickness to fit the outer diameter of the roll main body or by molding using a mold with good accuracy so as to obtain roundness. A Ni-stamper 1 formed by means of an electroforming is adhered and fixed on the die set. Therefore, when a defect is generated on the Ni-stamper, the Ni-stamper is exchanged one by one and application efficiency of the stamper is improved. When the Ni-stamper is exchanged, it is not necessary to dismount the roll main body from an extrusion molding apparatus to make the exchanging work easier.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is directed to the use of substrates for high-density information storage media such as optical discs, on which unevenness is formed for preformat signals and guide grooves for tracking signals. This relates to manufacturing equipment.

[Prior Art] Conventionally, substrates for high-density information storage media such as optical disks have been manufactured by injection molding, compression molding, etc., and substrates manufactured by these methods have poor flatness and smoothness. In addition, warping and air bubbles are likely to occur, which significantly impedes the detection of information by light. It is very difficult to prevent this, and it also requires large equipment, resulting in enormous costs. Furthermore, compression molding involves single-wafer processing, which has the drawback of complicated post-processing and poor productivity.

On the other hand, since plastic flat plates are easily manufactured into smooth and uniform plates without air bubbles, a method has also been proposed in which the unevenness of the stamper is transferred by placing a stamper in close contact with the plastic flat plate and applying pressure. However, there is a problem in that it requires a very large amount of pressure to apply pressure to the entire board surface.

One way to solve this problem is to pass the plastic sheet extruded from an extrusion molding machine between a molding roll with a stamper in close contact with it and a mirror-finished roll, so that the unevenness of the stamper is etched into the plastic sheet using a small amount of pressure. Then, by trimming the center hole and the outer periphery, an information recording medium substrate can be easily obtained using a small device.

FIG. 4 shows a partial longitudinal sectional front view of such a conventional stamper roll for extrusion molding. This stamper roll 14 is made by electroforming and has a thickness of 0.1 to 0. :1m5t
A plurality of Ni stampers 1 are bonded and fixed using an adhesive 4 to the surface of an extrusion roll body 3 having a heating medium therein.

FIG. 5 is a schematic diagram showing an extrusion molding apparatus using the stamper roll 14. In the same figure, an extrusion molding machine 11
The resin sheet 9 extruded from the T-die 12 and made to a constant thickness is pressed between the two pressure rolls 13 and ts and the stamper roll 14, and the group pattern on the stamper surface is transferred to form the resin sheet 9. The sheet becomes 1O. The obtained molded sheet)-10 is processed into an optical disc through a post-process.

[Problems to be Solved by the Invention] However, in the extrusion molding method shown in the above-mentioned conventional example, if a defect occurs in one stamper, the entire stamper roll body must be replaced, and multiple stampers must be replaced. In the case of a stamper roll in which stampers are bonded together, there is a drawback that the stamper usage efficiency is extremely poor.

In addition, when producing multiple sides, the number of stampers installed on the stamper roll increases, and the diameter of the stamper roll also becomes considerably larger, making it heavier and requiring considerable effort to attach and remove the stamper roll. Ta.

Furthermore, the larger the diameter of the stamper roll, the more difficult the work of gluing the stampers together becomes.
When an adhesion processing device is required, there is a problem in that the device itself becomes large.

The present invention was made to solve these conventional problems, and when a defect occurs in the stamper installed on the stamper roll, the stampers can be replaced one by one, and the stamper can be replaced one by one. Utilization efficiency can be improved, and when the stamper is pasted onto a roll, the stamper pasting process can be easily performed, and the stamper can be replaced without having to remove the roll body from the extrusion molding machine. It is an object of the present invention to provide an apparatus for easily manufacturing a substrate for an optical recording medium.

[Means for Solving the Problems] That is, the present invention uses an extrusion molding machine that extrudes a resin sheet, and three rolls including two pressure rolls sandwiching a stamper roll provided with a Ni stamper. In an apparatus for manufacturing a substrate for an optical information storage medium, a resin sheet extruded from an extrusion molding machine is passed between three wooden rolls and recorded and reproduced using light that transfers the unevenness of a Ni stamper to the resin sheet. This is an apparatus for manufacturing a substrate for an optical recording medium, characterized in that a stamper roll is used, in which a Ni stamper having irregularities formed thereon is fixed to a die set, and the die set is detachably attached to a roll body.

[Function] In the optical recording medium substrate manufacturing apparatus of the present invention, a die set that can be closely fixed along the outer cylindrical curved surface of the roll body of the stamper is provided for each Ni stamper, and the Ni stamper is attached to the die set. By bonding and fixing using adhesive and attaching the die set to the stamper body in a detachable manner, even if one Ni stamper becomes defective, only one die set needs to be replaced.
The utilization efficiency of the i-stamper is improved, and the work of attaching the Ni stamper to the die set and attaching and detaching the Ni stamper to the roll body can be performed extremely easily.

[Example] Hereinafter, the present invention will be described in more detail based on the example shown in the drawings.

Embodiment 1 FIG. 1 is a partially longitudinal sectional front view showing an example of a stamper roll used in the apparatus for manufacturing an optical recording medium substrate of the present invention, and FIG. 2 is a sectional view taken along line AA' in FIG. In the ts1 diagram, 3 is the roll body, for example, the diameter is 40 cm.
The size is wb + width 60cm, and the material C is a metal such as copper that has a large heat transfer coefficient.

However, since the surface of the roll body 3 is easily scratched, the surface layer is hardened or coated with a hard film.

A die set 5 made of a material having relatively high rigidity and a large heat transfer coefficient is removably attached to and fixed on the roll body 3 by die set fixing bolts 7. In order to maintain roundness, this die set 5 is formed by uniformly bending a relatively thin metal plate material to match the outside diameter of the roll body, or by using a highly accurate mold. Those molded to achieve roundness are used.

Furthermore, the die set includes N formed by electroforming.
The i-stamper 1 is pasted and fixed using an adhesive 4 or the like. Since the periphery of the Ni stamper is particularly susceptible to peeling, it is also possible to fix it with screws or the like. In the figure, the size of the Ni stamper 1 is, for example, about 20 cm x
One group pattern is formed on each sheet with a rectangular shape of about 50 cm. A heat vibrator 2 passes through the rotating shaft of the stamper roll, and heated oil is passed through the heat pipe 2 to heat the entire stamper roll.

The peripheral part of the Ni stamper 1 is fixed with two screws or rivets as shown in FIG. If there is a part, a concave part is provided around the part.

The stamper roll shown in FIG. 1 is used as the stamper roll 14 in the extrusion molding apparatus shown in FIG.
The group pattern on the Ni stamper can be transferred onto the resin sheet 9 which is placed between the pressure rolls 13 and 15 and extruded from the T-die 12. The temperature conditions at this time vary depending on the type of resin. For example, the temperature of the T-die is 180°C, and the temperature of the stamper roll is 150°C. Pressure roll 13. Is is also heated, and in the process of gradually lowering the temperature of the resin sheet, a molded sheet IO with groups is formed.

Embodiment 2 FIG. 3 is a partially vertical front view showing another example of a stamper roll used in the optical recording medium substrate manufacturing apparatus of the present invention. In the figure, the die set 5 is fitted and fixed by a die set fixing frame 8. When the stamper roll is set in the extrusion molding device and heated, the die set 5. The die set fixing frame 8 and the roll body 3 are stretched by [11] depending on their respective expansion coefficients, but at this time, the die set fixing frame 8 has an average coefficient of thermal expansion that
For example, a metal such as tungsten steel or carbon-rich stainless steel is used.

The die set and roll body are made of copper-based metal material with good thermal conductivity.

[Effects of the Invention] As explained above, in the optical recording medium substrate manufacturing apparatus of the present invention, a stamper roll is used in which a Ni stamper is fixed to a die set and the die set is detachably attached to a roll body. Therefore, if a defect occurs in the Ni stamper, the Ni stampers can be replaced one by one, improving stamper utilization efficiency.

■When bonding the Ni stamper onto a roll, there is no need to handle a large roll, and the process of bonding the Ni stamper becomes easier because it can be attached to a die set.

■When replacing the Ni stamper, there is no need to remove the roll from the extrusion molding device, making the Ni stamper replacement work easier.

[Brief explanation of drawings]

FIG. 1 is a partial longitudinal sectional front view showing an example of a stamper roll used in the apparatus for manufacturing an optical recording medium substrate of the present invention, FIG. 2 is a sectional view taken along line AA'i in FIG. 1, and FIG. FIG. 4 is a partial vertical front view showing another example of the stamper roll used, FIG. 4 is a partial vertical front view of a conventional stamper roll for extrusion molding, and FIG. 5 is a schematic diagram showing an extrusion molding apparatus using the stamper roll. . l...Ni stamper 2...Heat pipe 3...Roll body 4...Adhesive 5-Die set 6...Die set fixing screw hole 7...Die set fixing bolt 8... ...Die set fixing frame 9...Resin sheet lO...Mold flow sheet 11...Extrusion molding machine 12...Die 1:l, 15...Pressure roll 14...Stamper roll

Claims (1)

[Claims] Equipped with an extrusion molding machine that extrudes a resin sheet, and three rolls with two pressure rolls sandwiching a stamper roll equipped with a Ni stamper, the resin sheet extruded from the extrusion molding machine is Pass it between rolls and apply N to the resin sheet.
In an apparatus for manufacturing a substrate for an optical information storage medium that records and reproduces information using light that transfers the unevenness of an i-stamper, a Ni stamper on which a predetermined unevenness is formed is fixed to a die set, and the die set is detachably attached. An apparatus for manufacturing a substrate for an optical recording medium, characterized by using a stamper roll attached to a roll body.