JP3166231B2 - Manufacturing method of optical recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an optical disc (C
D, CD-ROM, CD-I, laser disk, write-once and rewritable disk, magneto-optical disk, etc., optical card (ROM-type card, write-once and rewritable card, magneto-optical card, etc.) The present invention relates to a method of manufacturing a recording medium by transferring pits by a roll embossing method, and particularly to a method of manufacturing an optical recording medium capable of producing a high-quality optical recording medium even when the embossing speed is increased. Things.

[0002]

2. Description of the Related Art In general, optical recording has advantages over magnetic recording in that a recording medium and a head are not in contact with each other and high-density recording is possible. Various types of optical recording media, such as a read-only type, an additionally writable type, and an erasable / rewritable type, are known. As read-only optical recording media according to the present invention, optical recording disks (CD, CD-
ROM, CD-I, laser disk, write-once and rewritable disk, magneto-optical disk, etc.) and optical card (ROM-type card, write-once and rewritable card, magneto-optical card, etc.) It has been put to practical use in various fields.

On the other hand, in the case of manufacturing an optical recording medium of this kind, when transferring pits as information signals, a thermoplastic resin is used as a substrate and a stamper is wound around for the purpose of reducing the manufacturing cost. There is a method of embossing with a hot roll.

That is, as shown in a schematic diagram in FIG. 8, a transfer sheet 1 made of a thermoplastic resin is unwound from an unwinding roll 2 and wound up by a winding roll 3 while being heated. In this method, the pits written on the stamper 6 are transferred by pressing the stamper 6 wound around the heat roll 4 against the transfer-receiving sheet 1 between the stamper 4 and the impression cylinder 5.

By the way, a stamper 6 used for manufacturing such an optical recording medium by the roll embossing method.
There are the following two methods for developing the pits.

First, as shown in a schematic diagram in FIG. 9, while rotating a master plate 7 after resist coating and laser exposure, a developing solution 9 is discharged from above by a developing solution discharge nozzle 8 as shown in FIG. This is a method of developing a (spray) pit. The cross section of the pit 10 has a steep outer wall surface angle as shown in FIG.

In the second method, as shown in a schematic diagram in FIG. 11, a master plate 11 after resist coating and laser exposure is immersed in a developing solution 13 accommodated in a developing tank 12 to form pits. This is a development method, and the cross section of the pit 14 has substantially the same wall angle in all directions as shown in FIG.

However, when embossing is performed using a stamper in which pits are developed by such a normal method, the transferred pits are distorted (blurred) as shown in FIG. 13 as the embossing speed is increased. ,
It becomes difficult to manufacture a high-quality optical recording medium. In the figure, reference numeral 15 denotes a transfer pattern.

[0009]

As described above, in a method for manufacturing an emboss type optical recording medium using a stamper in which pits are developed by a conventional method, a high quality optical recording medium is manufactured. There was a problem that was difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and when transferring pits by a roll embossing method to manufacture an optical recording medium, an extremely high embossing speed can be achieved. It is an object of the present invention to provide a highly reliable optical recording medium manufacturing method capable of manufacturing a quality optical recording medium.

[0011]

In order to achieve the above object, according to the present invention, a stamp is provided on a transfer sheet made of a thermoplastic resin by pressing a stamper provided on a heat roll. In a method of manufacturing an optical recording medium by a roll emboss method in which pits are transferred, a stamper is used in which a developing solution is flowed from a certain direction to a pit developed on a master disk after resist coating and laser exposure to develop pits. The pits are transferred by providing the stamper on the heat roll in such a direction that the wall surfaces of the transfer pits are offset by the wall surfaces of the stamper.

Here, in particular, the master disk is arranged in a state of being inclined at a predetermined first angle (60 degrees to 80 degrees) with respect to a horizontal plane, and the developer is discharged onto the master disk from above. The pit is developed by flowing in a certain direction.

Further, the master plate is inclined in a developing tank in which the developing solution flows in a certain direction by a predetermined second angle (0 ° (parallel to the flowing direction) to 30 °) with respect to the flowing direction. The pits are developed in a state where the pits are developed.

[0014]

Accordingly, in the method of manufacturing an optical recording medium according to the present invention, when pits are transferred to a transfer receiving sheet by a roll embossing method using a stamper provided on a heat roll, a resist is applied as a stamper. Using a stamper developed by flowing a developer from a certain direction to the pit after laser exposure on the master plate, the pit is transferred by setting the stamper on the heat roll in such a direction that the wall of the transfer pit cancels the wall of the stamper This makes it possible to transfer pits with high accuracy even when the embossing speed is increased, and to manufacture an optical recording medium of extremely high quality.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing an example of an apparatus configuration for realizing a method of manufacturing an optical recording disk which is an optical recording medium according to the present invention. FIG. 1 (a) is a front view thereof, and FIG. (b) is a plan view of the same. In FIG. 1, the master board 21 is inclined with respect to a horizontal plane by a predetermined first angle θ ₁ (the angle may be in the range of 10 to 90 degrees, preferably 60 to 80 degrees). A master board 22 after resist application and laser exposure is arranged.
Further, a developer discharge nozzle 23 is disposed immediately above the master board 22, and the developer 25 contained in the developer tank 24 is provided.
Is circulated by a pump 26 to discharge the developing solution 25 onto the master board 22. Note that 2 in the figure
7 indicates a signal portion.

Next, in such a configuration, the pump 2
6, the developing solution 25 in the developing tank 24 is circulated by the pump 26 so that the developing solution 25 is discharged from the developing solution discharge nozzle 23 onto the master plate 22 and flows in a certain direction to develop pits. To produce a stamper.

In this case, the flow rate of the developer 25 may be determined in consideration of the speed of the roll emboss, the temperature of the hot roll, the pit depth, the material of the sheet to be transferred, and the like.
Good results are obtained with ml or more. That is, the pit cross section of the stamper prepared by the method of the present embodiment has a shape as shown in FIG.

Next, as shown in FIG. 3, the stamper 28 thus manufactured is placed on the heat roll 2 in such a direction that the wall surface of the thermal transfer pit is offset by the wall surface of the stamper 28.
9 and a transfer embossed sheet 30
The substrate of the optical recording disk is manufactured by transferring pits to the substrate (31 is a transfer pattern).

In the above, as the resist,
Any positive resist can be used. For example, WAYCOAT204H manufactured by Fuji Hunt Co., Ltd. can be used. Also,
As the developer 25, an aqueous alkaline solution, for example, sodium hydroxide, potassium hydroxide, or the like can be used. Further, as a material of the transfer sheet 30, a thermoplastic resin, for example, vinyl chloride, acryl, polycarbonate, or the like can be used.

FIGS. 4, 5 and 6 compare the relationship between the pit shape of the stamper and the transfer pattern shape for the ideal case, the conventional method, and the method of the present embodiment. FIG.

That is, in the stamper in which the pits are developed by the above-described conventional method, as shown in FIG. 5, the angle of both wall surfaces of the pits is larger than 90 degrees, and when the stamper is used for embossing, One wall surface of the transferred pit is distorted as shown in FIG.
On the other hand, in the stamper 28 in which the pit is developed by the method of the present embodiment, the angle of one wall surface of the pit becomes steep as shown in FIG. 6, and when the stamper 28 is embossed using this stamper 28, Therefore, the pits are transferred in a suitable shape without distorting (dropping) any wall surface of the transferred pits.

More specifically, even if the emboss speed of the transfer pit according to the method of the present embodiment is increased from 10 to 30 m / sec, which is usually 1 to 5 m / sec, as shown in FIG. First, a high-quality optical recording disk could be manufactured.

As described above, in this embodiment, the pits written on the stamper 28 are transferred to the transfer sheet 30 made of thermoplastic resin by pressing the stamper 28 provided on the heat roll 29. In the method for manufacturing an optical recording disk according to the roll embossing method, the pits are developed by flowing the developing solution 25 from the fixed direction on the master plate 22 after resist application and laser exposure as the stamper 28 (specifically). The master plate 22 is disposed on the master platen 21 in a state where the master plate 22 is inclined at a predetermined first angle (60 degrees to 80 degrees) with respect to a horizontal plane, and the developer 25 stored in the developing tank 24 is provided.
Is circulated by a pump 26, and a developing solution 2 is supplied from a developing solution discharge nozzle 23 provided above the master board 22.
5 and discharge the pits in a certain direction to develop the pits). Using a stamper, the stampers 28 are provided on the heat roll 29 in such a direction that the wall surfaces of the transfer pits are offset by the wall surfaces of the stamper 28 so as to transfer the pits. It was done.

Therefore, the following various functions and effects can be obtained.

(A) As a stamper, a stamper 28 having a pit developed by flowing a developing solution 25 from a certain direction on the master plate 22 after resist application and laser exposure is used, and the wall surface of the transfer pit is offset by the wall surface of the stamper 28. The pits are transferred by providing the stamper 28 on the heat roll 29 in such a direction that the pits can be transferred with high accuracy even when the embossing speed is increased, thereby producing an extremely high quality optical recording disk. It can be manufactured.

(B) The developing machine of this embodiment can be manufactured at almost the same price as a conventional master disk developing machine.

(C) Except for the developing step, it is exactly the same as the conventional manufacturing method, and there is no change in the manufacturing step of the optical recording disk.

In the above embodiment, the pit is developed by flowing a developing solution from a certain direction on the master plate after resist coating and laser exposure.
At a predetermined first angle (60 degrees to 80 degrees) with respect to the horizontal plane.
(Degrees), the developing solution 25 contained in the developing tank 24 is circulated by a pump 26, and the developing solution discharge nozzle provided on the master plate 22 at a position above the master 25. The developer 25 is discharged from 23,
Although the case where the pit is developed by flowing in a certain direction has been described, the invention is not limited to this.

For example, as an example, as shown in a schematic diagram in FIG. 7, a master plate 41 after resist coating and laser exposure is placed in a developing tank 44 in which a developing solution 43 is circulated by a pump 42 and flows in a certain direction. It is arranged in such a manner that it is inclined by a predetermined second angle θ ₂ (0 to 60 degrees, preferably 0 to 30 degrees) with respect to the flow direction of the developer 43. The pits may be developed. In this case, for the same reason as described above, the flow rate of the developer 43 cannot be determined any more.
The volume of the part × 10 to 100 / min is preferred.

In each of the above embodiments, the case where the developer is circulated and used by the pump has been described. However, the present invention is not limited to this, and the developer may be disposable.

Further, in each of the above-described embodiments, the case where the present invention is applied to an optical recording disk has been described. However, the present invention is not limited to this, but also applies to an optical card and other sheet-like optical recording media. The same effects can be obtained by applying the invention in exactly the same manner.

[0033]

As described above, according to the present invention, the pits written on the stamper provided on the heat roll are transferred to the transfer sheet made of the thermoplastic resin by pressing the stamper. In a method for producing an optical recording medium by a roll embossing method,
As a stamper, use a stamper that has developed pits by flowing developer from a certain direction on the master board after resist coating and laser exposure, and apply the stamper to the heat roll in a direction that offsets the transfer pit wall surface by the stamper wall surface. Since the pits are provided and the pits are transferred, when the pits are transferred by the roll embossing method to manufacture an optical recording medium, it is possible to produce an optical recording medium of extremely high quality even when the embossing speed is increased. It is possible to provide a method for manufacturing a highly reliable optical recording medium.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of a method for manufacturing an optical recording disk which is an optical recording medium according to the present invention.

FIG. 2 is a sectional view showing an example of a pit sectional shape of a stamper in the embodiment.

FIG. 3 is a schematic diagram for explaining a pit transfer method in the embodiment.

FIG. 4 is a cross-sectional view showing a relationship between a pit shape of a stamper and a transfer pattern shape in an ideal case.

FIG. 5 is a cross-sectional view showing a relationship between a pit shape of a stamper and a transfer pattern shape when a conventional method is used.

FIG. 6 is a sectional view showing the relationship between the pit shape of the stamper and the transfer pattern shape when the method according to the embodiment is used.

FIG. 7 is a schematic diagram showing another embodiment of a method for manufacturing an optical recording disk which is an optical recording medium according to the present invention.

FIG. 8 is a schematic diagram for explaining an example of a pit transfer method using a roll embossing method.

FIG. 9 is a schematic diagram for explaining an example of a conventional method for developing pits of a stamper.

FIG. 10 is a view showing a cross-sectional shape of a pit according to the method of FIG. 9;

FIG. 11 is a schematic diagram for explaining another example of a conventional method for developing pits of a stamper.

FIG. 12 is a view showing a cross-sectional shape of a pit according to the method of FIG. 11;

FIG. 13 is a diagram showing a pit cross-sectional shape transferred when the embossing speed is increased.

[Explanation of symbols]

Reference Signs List 21: Master board base, 22: Master board, 23: Developing solution discharge nozzle, 24: Developing tank, 25: Developing solution, 26: Pump, 27: Signal part, 28: Stamper, 29: Heat roll, 30: Transfer Sheet, 31 ... transfer pattern, 41 ...
Master board, 42 pump, 43 developer, 44 developing tank.

Claims (5)

(57) [Claims] 1. A transfer sheet comprising a thermoplastic resin,
In a method of manufacturing an optical recording medium by a roll embossing method, in which a pit written on the stamper is transferred by pressing a stamper provided on a heat roll, after the resist coating and laser exposure, On the master plate, using a stamper developed by flowing a developer from a certain direction to develop pits, the stamper is provided on a heat roll in a direction such that the wall surface of the transfer pit cancels the wall surface of the transfer pit, and the pits are transferred. A method for manufacturing an optical recording medium, comprising: 2. The pit is developed by disposing the master disc at a predetermined first angle with respect to a horizontal plane, discharging a developing solution from above the master disc onto the master disc and flowing the developing solution in a certain direction. 2. The method for manufacturing an optical recording medium according to claim 1, wherein: 3. The first angle is 60 degrees to 80 degrees.
3. The apparatus according to claim 2, wherein the angle is inclined only by degrees.
3. The method for producing an optical recording medium according to item 1. 4. The pit is developed by disposing the master disk in a developing tank in which a developing solution flows in a certain direction, in a state inclined at a predetermined second angle with respect to the flowing direction. The method for manufacturing an optical recording medium according to claim 1, wherein: 5. The method of manufacturing an optical recording medium according to claim 4, wherein the second angle is inclined from 0 degrees (parallel to the flow direction) to 30 degrees.