JPH03176842A - Resin stamper for producing optical disk - Google Patents

Abstract

PURPOSE:To allow production of diversified kinds in a small quantity with a relatively simple stage by consisting the resin stamper of an information recording layer consisting of a specific photopolymer agent for stampers and a stamper substrate holding the information recording layer. CONSTITUTION:This photopolymer agent for stampers consists of the essential component monomer which is the benzene ring-contg. bifunctional acrylate or methacrylate expressed by formula I, the side component monomer which is the fluorine-contg. monofunctional acrylate or methacrylate expressed by formula II and a photopolymn. initiator of 1 to 10wt.% of the entire part, has the weight ratios of the essential component monomer: the side component monomer=90 to 99.9:10 to 0.1 and has the high peelability from metals. This resin stamper consists of the information recording layer consisting of the above- mentioned photopolymer agent and the stamper substrate holding the information recording layer. In the formula I, R1 is H or CH3; R2 is -CH2CH2O-, etc.; the sum of m and n is 2 to 10 integer (m>=1, n>=1). The production process is simplified in this way and the production of diversified kinds in a small quantity is facilitated.

Description

TECHNICAL FIELD The present invention relates to a resin stamper for manufacturing optical discs such as video discs and compact discs.

BACKGROUND ART Conventionally, as a method for manufacturing an optical disc, a method as shown in the flowchart of FIG. 5 has been known.

According to this manufacturing method, first, as shown in FIG. 6(al), a photoresist layer 2 is uniformly formed on the main surface of the glass disk 1.
Prepare a photoresist master disk with a pattern formed thereon, and perform the laser cutting process S. In this step, a latent image of a spot array corresponding to predetermined information is formed in a spiral or concentric pattern on the photoresist layer 2 by a laser beam La.

Next, in the developing step S1, the exposed photoresist master disk is mounted on a developing device and developed, thereby forming a row of minute irregularities (hereinafter referred to as pits) corresponding to the signal to be recorded on the photoresist master disk, A photoresist layer 2 having pits, which is an information recording layer, as shown in FIG. 6(a2)
A developing master disk consisting of the glass disk 1 and the glass disk 1 is obtained.

Next, in a post-baking step S2, the photoresist layer 2 of the development master is dried and fixed on a glass disc to obtain a dry master as shown in FIG. 6(b).

Next, in a silver sputtering step S3, silver is sputtered to form a silver conductive film 3 on the photoresist layer 2, thereby obtaining a stacked mastering master 3a as shown in FIG. 6(c). In this manner, the information recording surface having pits is made conductive by sputtering metal onto the photoresist layer having pits. The above process is the mastering master creation process.

Next, regarding the Ni stamper production process, first in the Ni electroforming process S4, the obtained mastering master is immersed in a nickel electroforming bath and nickel (Ni) is plated on the silver conductive film 3 to form a thick nickel Layer 4, ie, a nickel stumper, is formed to obtain a structure as shown in FIG. 6(d).

Next, in the stamper separation step S5, as shown in FIG.
As shown in the figure, the stamper, which is the nickel layer 4, is separated from the glass disk 1.

Next, in a photoresist stripping step S6, the photoresist layer 2 remaining on the nickel layer 4 is stripped off, as shown in FIG.
A structure as shown in f) is obtained.

Alkaline solutions or commercially available organic solvents are used to remove photoresists.

Next, in a silver peeling step S2, the silver conductive film 3 is peeled off from the nickel layer 4, and the periphery of the nickel layer 4 obtained in a stamper processing step S8 is processed to form a nickel stamper as shown in FIG. 6(g). get.

The above process is the nickel stamper manufacturing process.

Next, before starting the injection molding process as a replica production process, a nickel stamper is attached to a predetermined position of the injection molding apparatus 5 (stamper attachment process S9), as shown in FIG. 6(h).

Next, as shown in FIG. 6(i), after the mold is clamped, the injection molding device 5 is operated to inject molten transparent resin materials such as PMMA (polymethacrylate) and PC (polycarbonate) onto the nickel stamper. After the resin material has hardened, it is taken out to create an optical disk replica having a predetermined information recording surface as shown in FIG. 6(j) (injection molding step 510). The above process is the replica creation process.

The thus obtained replica is coated with a reflective film made of aluminum or the like on the information recording surface of the replica (Sll) by a known method, and a protective film is further overcoated on the reflective film (S12). , an optical disc is formed. In addition, two of these optical discs are pasted together (813)
After passing through a finishing process (S14), the disc is usually made into a double-sided optical disc.

In such a conventional manufacturing method, a stamper for manufacturing an optical disk is made of nickel (Ni), which has excellent durability even in replica injection molding.

However, as mentioned above, the manufacturing of nickel stambars requires many steps in the electroforming process, and plating takes time.Furthermore, since the injection molding equipment for manufacturing replicas is relatively large, it takes time and effort to replace nickel stambars. It takes. The conventional nickel stamper method has no problem in mass production, but it is not suitable for manufacturing optical discs compatible with the recent small-volume production of a wide variety of video and audio software.

Summary of the Invention [Object of the Invention] An object of the present invention is to provide a stamper for manufacturing optical disks that is suitable for small-lot, high-mix, and mass production using relatively simple steps.

[Structure and operation of the invention] The stamper for manufacturing an optical disk according to the present invention is a stamper itself formed of resin, and R1 is H or CH.
, and R2 is CH.

CH2CH2O- or -CH2CHO-, m
and a main component monomer which is a benzene ring-containing bifunctional acrylate or methacrylate represented by the following formula (AI), where the sum of 2 and n is an integer of 2 to 10 (m≧1, n≧1), and R1 is H or CH3, is an integer of 1 to 8, and β is an integer of 3 to 8; a subcomponent monomer that is a fluorine-containing monofunctional acrylate or methacrylate represented by the following formula (A2); and a photopolymerization initiator of 1 to 10 Vt.%, and the weight ratio of the main component monomer to the subcomponent monomer is 90 to 99.9:10 to 0. The present invention is characterized by comprising an information recording layer made of a photopolymer agent for a stamper that has high releasability with respect to metal, and a stamper substrate that holds the information recording layer.

Here, the photopolymer agent is a substance that hardens from a fluid to a solid upon irradiation with radiation such as ultraviolet rays.

The photopolymer agent for stampers that has high releasability to the above metals has hydrophobicity because the fluorine and benzene rings are nonpolar. Since the molecular structures of the sub- and main component monomers include such hydrophobic atomic groups and molecular skeletons of fluorine and benzene rings, the photopolymer agent for stampers is desirable because it has high releasability to metals after curing. Further, the fluorine-containing monomer as a subcomponent is more effective in terms of hydrophobicity if the fluorine atoms are oriented on the surface of the photopolymer agent layer. Therefore, the fluorine-containing monomer is preferably monofunctional. This is to free fluorine in the crosslinked structure. This fluorine-containing monomer also improves releasability from the photopolymer agent that forms the replica during replica creation.

Furthermore, the photopolymer agent for stampers described above improves the transferability during development of the photopolymer agent in the transfer step. That is, the fluorine-containing monomer also has a function as a surfactant, and has the effect of improving wettability with metal films such as silver and aluminum, and lowering the dynamic contact angle during transfer. This also prevents the generation of voids and improves transfer accuracy after curing. On the other hand, since the surface tension of the photopolymer side threads decreases, the filtration rate increases compared to monomers of the same viscosity.

Furthermore, the photopolymer agent for stampers has durability as a stamper and has a low curing shrinkage rate. the above(
This is because the main component monomer skeleton of R2 in formula A1) suppresses shrinkage during curing. Furthermore, in order to provide durability, the main component monomer needs to be crosslinked. However, for crosslinking, it is necessary to use a polyfunctional (bifunctional or higher) monomer as the main component monomer, but while trifunctional or higher functional monomers increase the curing speed, they also significantly increase the curing shrinkage rate, lower transfer accuracy, and reduce cupping. The adhesive strength with the ring agent decreases. However, the bifunctional monomer is the most well-balanced main component monomer.

Furthermore, since the above-mentioned photopolymer agent for a stamper contains a low-viscosity monomer such as a photopolymerization initiator in an amount of 10 wt.% or less, it does not attack the photoresist of the mask ring master. Low viscosity monomer (regardless of the type of monomer,
This is because photopolymer side yarns containing 10 νt, % or more of LOOcps or less tend to attack the photoresist.

Furthermore, the photopolymer agent for stampers described above has good UV curability. Since the main component monomer having a benzene skeleton shows strong absorption in the ultraviolet region, the thin film (photopolymer agent layer) has high ultraviolet absorption efficiency and increases the curing speed by ultraviolet rays.

The weight ratio of the main component monomer to the subcomponent monomer is 90-99.9:10-0.
It is desirable that the number be within the range of 1.

The present invention will be explained below with reference to the drawings.

FIG. 1 shows a diametrical cross-sectional view of a resin stamper according to the invention. The resin stamper 13a consists of a stamper 1, an information recording layer of a stamper photopolymer agent 11, and a glass disk 13 which is a stamper substrate supporting the information recording layer. Furthermore, FIG. 2 shows a diametrical cross-sectional view of a previous disk replica manufactured from a resin stamper according to the present invention. The optical disk replica 23a consists of an information recording layer made of a photopolymer agent 21 for replica and a PMMA disk 23 which is a replica substrate supporting the information recording layer.

FIG. 3 shows a flowchart of the manufacturing process of an optical disk replica using the resin stamper according to the present invention.

In this manufacturing process, steps up to the silver sputtering step S3 for obtaining a mastering master are carried out in the same manner as in the conventional method shown in FIG. The optical disc manufacturing process of this embodiment differs from the conventional method in the process of manufacturing a nickel stamper and a replica.

First, in the stamper manufacturing process, using the so-called 2P transfer method in which a cured photopolymer agent is used as a transfer layer, the silver-coated mastering master obtained in the silver sputtering process S3 is used as a mold, and information is transferred using a photopolymer agent for the stamper. The recording surface is transferred onto a stamper substrate, that is, a glass disk, and a resin stamper is formed instead of a nickel stamper.

Specifically, the 2P transfer method uses a mastering master disk 3a whose information recording surface is coated with a metal film, as shown in FIG. 4(a).
is placed horizontally on the table 10 of the transfer device so that its information recording surface faces upward (master fixing step 521).

After that, as shown in FIG. 4(b), the mastering master 3
A liquid stamper photopolymer agent 11 that is highly releasable to the metal film is applied onto the information recording surface of a (photopolymer agent supply step 522).

Next, as shown in FIG. 4(C), a transparent glass disk 13 coated with a silane coupling agent 12 as a substrate pretreatment is placed on a stamper substrate jig 14 of a transfer device.
While keeping the jig 14 horizontal, lower the jig 14, place it concentrically on the mastering master disk 3a via the stamper photopolymer agent 11, position it, and place the stamper on the entire space between the glass disk 13 and the mastering master disk 3a. Photopolymer agent 11
3 times (photopolymer agent development step 523).

Thereafter, as shown in FIG. 4(d), the stamper photopolymer agent 11 is cured by irradiating ultraviolet rays (arrow) from the glass disk 13 side to the stamper photopolymer agent 11, and is coated on the main surface of the glass disk 13. An information recording layer made of a photopolymer agent for a cured stamper is formed or transferred (ultraviolet irradiation step 524).

Next, as shown in FIG. 4(e), the mastering master 3a
The glass disk 13 is peeled together with the information recording layer of the photopolymer agent for stamper from the resin stamper 13a, which is made up of the information recording layer of the photopolymer agent for stamper 11 and the glass disk 13 supporting it (peeling step 525). ). In this resin stamper manufacturing process, the conventionally known 2P
A so-called 2P transfer device is used to carry out the transfer method, and the process from fixing the mastering master 3a to removing the resin stamper 13a is performed automatically.

Subsequently, a replica is manufactured using the obtained resin stamper 13a as a mold. This replica manufacturing process is not the conventional injection molding using molten PMMA and PC, but is similar to the resin stamper manufacturing process described above.
Using the P transfer method and apparatus, an optical disk replica is formed by transferring the information recording surface onto a replica substrate, that is, a cured PMMA substrate, using a photopolymer agent for replica.

Specifically, as shown in FIG. 4(f), the obtained resin stamper 13a is placed horizontally on the table 10 of the transfer device with its information recording surface facing upward (stamper fixing step 826).

After that, as shown in FIG. 4(g), the resin stamper 13a
On the information recording surface of the hardening stamper photopolymer agent 1
A liquid replica photopolymer agent 21 with high releasability is applied to the photopolymer agent 1 (photopolymer agent supply step 527).

Next, as shown in FIG. 4(h), as a substrate pretreatment, a transparent PMMA plate 23 coated with a photopolymer agent 12 for improving adhesion is placed on the stamper substrate jig 14 of the transfer device.
The jig 14 is lowered while keeping the entire A board 23 23, and placed concentrically on the resin stamper 13a via the replica photopolymer agent 21, positioned, and then the PMMA board 23 all 23 resin stamper 13a is placed. The replica photopolymer agent 21 is spread over the entire space (photopolymer agent spreading step 528). After that, as shown in FIG. 4(i), from the PMMA board 23 side, the replica photopolymer agent 2 is
1 is irradiated with ultraviolet rays (arrow) to harden the replica photopolymer agent 21, and an information recording layer made of the cured replica photopolymer agent is formed or transferred on all 23 of the PMMA disk 23 (ultraviolet ray irradiation step 529). Next, as shown in FIG. 4(j), all 2 of the PMMA discs 23 are removed from the resin standber 13a together with the information recording layer of the photopolymer agent for the replica.
3, an optical disk replica 23a1, a so-called 2P replica, consisting of the information recording layer of the replica photopolymer agent 21 and the PMMA disc 23 supporting the information recording layer is obtained (peeling step 530).

A 2P transfer device is also used in this 2P replica manufacturing process, and the process from fixing the resin stamper 13a to taking out the resin stamper is automatically performed.

The replica thus obtained is prepared by forming a reflective film of aluminum 6 ram or the like on the information recording surface of the replica by a known method, and then overcoating the reflective film with a protective film. Two optical disk replicas are pasted together and a finishing process is performed to obtain a double-sided optical disk.

Effects of the Invention As described above, the optical disk manufacturing resin stamper of the present invention is a stamper made of a photopolymer agent that is releasable to the metal of the information recording surface of the mask ring master.
In this way, a replica is created using the 2P transfer method. Therefore, in the optical disc manufacturing process, the manufacturing process is simplified while achieving accurate transfer of the information recording surface, and it is possible to manufacture an optical disc compatible with a wide variety of video and audio software in small quantities.

Example Photopolymer agent for stamper In the general formula (A1), R, = CH3, R2 = -CH2CH2O-, m+n =
6, 97 parts by weight of a methacrylate monomer having the general formula (A
In 2), 3 parts by weight of an acrylate monomer with R,=H,K-1,,F=3 and 2 parts by weight of benzophenone and 1-hydroxycyclohexyl ketone as photopolymerization initiators were mixed to give a viscosity of 40%.
A solution of 0 eps was prepared.

After pouring this solution in a ring shape around the periphery of the master link master disk 3a whose information recording surface is coated with silver according to the process shown in FIG. Press the stamper photopolymer agent 1 between the glass disk 13 and mask ring master disk 3a so that
1 over the glass plate 13, and then a metal halide lamp (50W/cm) is used to apply a wire of 1k150mJ/
The photopolymer agent 11 was cured by irradiating ultraviolet light with cJ (wavelength: 385 nm).

Next, the glass disk 13 was separated from the mastering master disk 3a to create a resin stamper 13a having an information recording layer made of photopolymer.

Subsequently, a photopolymer agent for replicas (01022 manufactured by Hitachi Chemical Co., Ltd.) was poured in a ring shape onto the resin stamper 13a obtained, and then a transparent PMMA board 23 with a thickness of 1.2 mm and a total thickness of 50 μm was poured. 8, spread the replica photopolymer agent 21 between the top three resin stands 13a of the PMMA board 23, and then apply a dose of L50 tnJ from the top of the PMMMA board 23.
/ am (wavelength: 365 nm) to cure the photopolymer agent 21.

Next, from the resin stamper 13a to the PMMA board 23, top 3
An optical disk replica 23a having an information recording layer made of photopolymer was obtained.

As a result, the optical disk manufacturing method using the resin stamper of the present invention takes about half the time or less of the conventional manufacturing method in which a nickel stamper is created by electroforming and a replica is created from the nickel stamper by injection molding. We were able to manufacture a replica of an optical disc.

[Brief explanation of drawings]

FIG. 1 is a diametrical cross-sectional view of a resin stamper according to the present invention;
FIG. 2 is a diametrical cross-sectional view of an optical disk replica manufactured from the resin stamper according to the present invention, and FIG. 3 is a flowchart showing the main steps of the method for manufacturing an optical disk using the resin stamper according to the present invention. 4 is a schematic sectional view of members in the 2P transfer step of FIG. 3, FIG. 5 is a flowchart showing a conventional optical disc manufacturing method, and FIG. 6 is a schematic sectional view of members in each step of FIG. 5. . Explanation of symbols of main parts 3a...Mastering mastering disc 11...Stamper photopolymer agent 13...
... Glass disk 21 ... Photopolymer agent for replica 23 ...
...PMMA board

Claims (1)

[Claims] R_1 is H or CH_3, and R_2 is -CH_
2CH_2O- or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and the sum of m and n is an integer from 2 to 10 (m≧1, n
≧1) Benzene ring-containing 2 represented by the following formula (A1)
The main component monomer is a functional acrylate or methacrylate, ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (A1) and R_1 is H or CH_3, k is an integer from 1 to 8, and l is 3 The following formula (A2) is an integer between 8 and 8.
A subcomponent monomer that is a fluorine-containing monofunctional acrylate or methacrylate shown in ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (A2) and 1 to 10 wt. % photopolymerization initiator, and the weight ratio of the main component monomer to the subcomponent monomer is 90 to 99.9:10 to 0.1. 1. A resin stamper for manufacturing optical discs, comprising an information recording layer made of a photopolymer agent for a stamper that has removability, and a stamper substrate holding the information recording layer.