JPH05200757A - Flexible stamper, roll-shaped stamper and production of substrate for optical data recording medium - Google Patents

Abstract

PURPOSE:To prevent the generation of an uneven flaw or transfer irregularity in the fine uneven pattern of a substrate for a data recording medium molded by a roller group molding method by providing a heat insulating layer to the interior of a flexible stamper. CONSTITUTION:A photoresist film is formed on a glass substrate and exposed and developed to form an uneven pattern. A conductive film and a metal film due to an electroforming method are successively formed thereon. After the surface of the metal film is ground, a heat insulating layer 2 such as a polyimide film having heat conductivity lower than that of the metal film is formed. The conductive film and the metal film are again formed on the layer 2 to be ground and the glass substrate is released to form a flexible stamper 1. The fixing jig 24 of this stamper 1 is welded to be fitted in the groove provided roller to form a roll-shaped stamper for molding a roller group. Further, a flexible stamper 23 may be formed by a known method to provide a porous layer 22 between the stamper 23 and a mirror surface roller 21.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is useful in a roller / groove molding method for forming irregularities on a substrate for an optical information recording medium,
The present invention relates to a flexible stamper, a roll stamper, and a method for manufacturing a substrate for an optical information recording medium using the stamper.

[0002]

2. Description of the Related Art Conventionally, magnetic materials such as magnetic tapes and magnetic disks, and various semiconductor memories have been mainly used for recording various information. Magnetic memory like this,
The semiconductor memory has an advantage that information can be written and read easily, but on the other hand, there are problems that the content of information can be easily rewritten and high-density recording cannot be performed.

In order to solve such problems, an optical information recording method using an optical information recording medium has been proposed as a means for efficiently handling a wide variety of information, and an optical information recording carrier and a recording / reproducing method therefor have been proposed. A recording / reproducing apparatus has been proposed. The optical information recording medium as such an information recording carrier, in general, volatilizes a part of the optical recording layer on the information recording carrier using a laser beam, causes a change in reflectance, or causes deformation, Information is recorded or reproduced by the difference in optical reflectance or transmittance. In this case, the optical recording layer is a so-called DRAW (direct read after write) medium that can be “directly read after writing” without requiring development processing after writing information, and high density recording Since it is possible and additionally writable, it is effective as a recording / storing medium of information.

In a general optical information recording medium, a polycarbonate resin or a polymethylmethacrylic resin, which is a thermoplastic resin, is used to transfer the unevenness using a stamper on which an uneven pattern corresponding to tracks and information is recorded. Forming a groove.

As a method for forming a groove on a substrate for an optical information recording medium, an injection molding method or a compression molding method is adopted. However, the specifications of the optical information recording medium substrate require that the flatness and smoothness of the substrate be high at the optical level. In the injection molding method or the compression molding method, defects such as warpage and inclusion of bubbles are liable to occur, which significantly impedes the detection of information by light.
Since it is very difficult to control the pressure, the precision of the mold, the prevention of the generation of bubbles, etc., and the size of the apparatus itself becomes large, the production cost is high. Furthermore, since the compression molding method is a single-wafer treatment, the post-process is complicated and the productivity is low.

[0006] Since a plastic flat plate can be easily manufactured with a smooth and uniform plate with few bubbles mixed therein, a method has been proposed in which a stamper is brought into close contact with this flat plate to apply pressure to transfer the uneven pattern. To apply a uniform pressure to the whole, a very large pressure was required.

As a method of solving this, a molten resin extruded from a T die of an extruder is passed between a molding roller (roller stamper) and a mirror surface roller, and an uneven pattern of the molding roller is transferred with a small pressure. There is a method of manufacturing a substrate for an optical information recording medium by the roller / groove molding method.

The roll stamper used in this method is
A mechanism in which fixing tools are welded to both ends of a flexible stamper with unevenness, and a groove having almost the same shape as the fixing tool is made on the roller, and the fixing tool is inserted into this groove, and tension is applied to at least one of the fixing tools. Was provided to fix the flexible stamper to the roller.

[0009]

However, as described above, optical information recording media such as optical cards and optical disks have strict characteristic values such as flatness and transferability of fine irregularities, so that molding rolls to be molded are not uniform. In that case, there arises a problem that an extremely fine concave-convex pattern is not accurately transferred, the substrate thickness becomes uneven, and the flatness becomes poor. Polycarbonate is used as the substrate material of the optical information recording medium because of its characteristics such as light transmittance, durability and mechanical strength. However, polycarbonate has optical anisotropy and has a problem that birefringence occurs when strain is applied. When birefringence occurs, the amount of laser light for recording / reproducing changes, which leads to deterioration of C / N and the like.

Further, when a molten polycarbonate extruded from an extruder is passed between a molding roller and a mirror surface roller to transfer a fine uneven pattern, molding distortion occurs during the molding, resulting in birefringence. I will end up. That is, in order to achieve high transferability, a large molding strain must be applied, and in order to achieve low birefringence, the molding strain must be suppressed as small as possible.

In order to accurately transfer the above-mentioned fine concavo-convex pattern and to manufacture a low birefringence sheet free from molding distortion, the applicant of the present application has previously proposed in Japanese Patent Application No. 3-249203 that a roller and a stamper are used. We proposed a molding roll with a resin layer in between. This resin layer functions as a heat insulating material between the stamper and the mirror surface roll, improves transfer of the uneven pattern of the substrate at the time of molding, alleviates molding distortion, and makes it difficult to cause birefringence. Furthermore, the adhesion between the mirror-finished roll and the stamper is improved to reduce the uneven heat distribution. However, in the transferability of the fine concavo-convex pattern in the medium substrate, higher fidelity to the stamper is required.

The present invention has been made to solve the problems in the prior art as described above.

That is, one object of the present invention is to prevent the occurrence of defects such as unevenness defects and transferability unevenness in a fine unevenness pattern of a substrate for optical information recording media molded by a roller / groove molding method. (EN) Provided are a flexible stamper provided with a heat insulating layer and a roll stamper including the flexible stamper.

Another object of the present invention is a roll-shaped stamper equipped with a stamper which accurately transfers a fine concavo-convex pattern when a molten resin is molded by a roll and does not cause molding distortion or floating refraction. In particular, an object of the present invention is to provide a substrate capable of highly accurately transferring an extremely fine uneven pattern required for a substrate for an optical information recording medium.

[0015]

One of the objects of the present invention is to provide a flexible stamper having a heat insulating layer having a lower thermal conductivity than that of a constituent material of the stamper, and a roll stamper having the same. Can be achieved with a stamper.

Another object of the present invention is a roll-shaped stamper comprising a roll and a flexible stamper provided on the surface of the roll, wherein at least one roll stamper is provided between the roll and the flexible stamper. This can be achieved by a roll-shaped stamper having a porous layer.

[0017]

When the flexible stamper of the present invention having the heat insulating layer inside is used as a roll stamper, the heat insulating layer moves unlike the conventional roll stamper provided between the roll and the flexible stamper. It is possible to prevent irregularities and irregularities in transferability when forming a fine concave-convex pattern of the optical information recording medium substrate by the roller / groove molding method.

Further, in the roll-shaped stamper of the present invention having a porous layer, since the air has a low thermal conductivity, the porous layer enclosing air acts as an extremely effective heat insulating layer in terms of the heat insulating effect, Good transfer of uneven patterns on the substrate during molding.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a flexible stamper of the present invention having a heat insulating layer inside will be described in detail below with reference to the drawings.

FIG. 1A is a schematic view showing an example of a flexible stamper (with a fixing tool) of the present invention.
(B) is the AA 'cross section figure. The flexible stamper 1 shown in FIG. 1 has a predetermined concavo-convex pattern 15 corresponding to the fine concavo-convex pattern of the optical information recording medium substrate, a heat insulating layer 2 inside thereof, and flexible stampers at both ends thereof. Has a fixture 4 for fixing the roller to the roller.

FIG. 2 is a schematic sectional view showing an example of the roll stamper of the present invention. The roll-shaped stamper 5 shown in FIG. 2 is provided with the flexible stamper 1 having the heat insulating layer 2 shown in FIG. 1 by inserting the fixing tool 4 into a predetermined groove of the roller 17.

FIG. 3 is a process explanatory view showing an example of a method for manufacturing the flexible stamper 1 having the heat insulating layer 2 inside according to the present invention. In the manufacturing method shown in FIG. 3, first, as shown in FIG. 3 (A), a glass substrate 6 such as soda lime glass is used.
A photoresist 7 is formed on top. Next, as shown in FIG. 3B, the photoresist is exposed and developed to form a fine concave-convex pattern 7 ′ such as tracking grooves and information pits, which is used as a glass master 8. Next, as shown in FIG. 3C, a conductive film 9 is formed on the pattern 7 '. Next, as shown in FIG. 3D, a metal film 13 is formed on the conductive film 9 by electroforming, and the surface is polished. Then, as shown in FIG.
The heat insulating layer 2 such as an ultraviolet curable resin having a lower thermal conductivity than the metal film 13 or a polyimide film is formed. Then Fig. 3
As shown in (F), after forming a conductive film (not shown) on this, the metal film 13 is formed again by electroforming to form the heat insulating layer 2
Are formed so as to be included inside the metal film. Then
After the metal film 13 is polished, as shown in FIG. 3G, the conductive film 9 and the metal film 1 are separated from the glass master 8 in an integrated state, whereby a heat insulating layer is formed inside. A flexible stamper 1 having 2 is obtained.

FIG. 4 shows an RG device (roller groove device) which can be used in the method for manufacturing a substrate for an optical information recording medium of the present invention.
It is a typical sectional view showing an example. First, extruder 11
A pellet-shaped resin such as polycarbonate pellets is extruded at a constant speed while melting with a T-die 1
By 0, the shape is approximated. The molten resin extruded from the T-die 10 is provided between the roll-shaped stamper 5 having the flexible stamper 1 having the heat insulating layer 2 inside as described above, and the mirror surface roller 12 for adjusting the plate thickness and the mirror surface. Through the gap, fine patterns of irregularities such as tracking grooves and information pits are continuously transferred with a small pressure. As a result, a continuous sheet of optical information recording medium substrate is obtained. As the resin used as the substrate material here, for example, polycarbonate, polyolefin,
Resins such as polyester and polyether sulfone are appropriately used.

The roller 17 for forming the roll stamper of the present invention can be made of any material as long as it has high hardness and good thermal conductivity. For example, steel, chromium, etc. A metal such as steel can be used. The surface precision of the roller 17 is preferably approximately the same as or better than the surface precision of the optical information recording medium substrate to be molded. Further, if necessary, it is possible to apply a hardened film of titanium nitride or the like or a plating such as a chrome plating on the surface. The thickness of the stamper 1 is preferably thinner than that generally used for injection in order to attach the stamper to the roller. The range is preferably about 10 to 300 μm, and more preferably the thickness is 30 to 200 μm.

Next, the roll stamper of the present invention having a porous layer between the roll and the flexible stamper will be described in detail below with reference to the drawings.

FIG. 5 is a schematic view showing an example of the roll stamper of the present invention, and FIG. 6 is a schematic perspective view thereof. The roll-shaped stamper 20 shown in FIG. 5 includes a mirror roller 21, a flexible stamper 23, and a porous layer 22.
As a fixture 24 via a porous plastic sheet
It is fixed by.

FIG. 7 is a schematic cross-sectional view showing an example of an apparatus that can be used in the method for manufacturing a substrate for an optical information recording medium of the present invention. As shown in FIG. 7, the thermoplastic resin 26 extruded from the extruder 1 is heated and pressed between the roll stamper 20 and the mirror surface rolls 27 and 28 of the present invention to transfer a preformat pattern or information signal. ..

As the resin 26 used as the substrate material, for example, resins such as polycarbonate, polyolefin, polyester and polyether sulfone are appropriately used.

The roller 21 for forming the roll stamper 20 of the present invention can be made of any material as long as it has high hardness and good thermal conductivity. For example, steel or chrome steel can be used. Metals such as can be used. The processing accuracy of the surface of the mirror surface roller 21 is preferably approximately the same as or better than the surface accuracy of the optical information recording medium substrate to be molded. Further, if necessary, it is possible to apply a hardened film of titanium nitride or the like or a plating such as a chrome plating on the surface.

The flexible stamper 23 here is
It may be manufactured by a known manufacturing method generally used for CDs (compact disks) and the like. Specifically, after applying a resist to the glass master and exposing and developing the pattern,
Nickel is sputtered into a film and electroformed to deposit nickel to a predetermined thickness. The stamper thus obtained may be used as a second master to further produce a grandchild stamper.

The thickness of the stamper 23 is
In order to bond the resin to the roller 21, it is preferable to use a thinner material than that generally used for injection. The range is preferably about 10 to 300 μm, and more preferably the thickness is 30 to 200 μm.

The stamper thus formed is fixed and closely attached to a mirror surface roll, and the roll-shaped stamper 2 of the present invention is used.
However, as described above, the resin 26 such as polycarbonate extruded from the extruder 25 causes the roll stamper 20 and the mirror-finished rollers 27 and 28 to move.
Then, the uneven pattern of the roll stamper and the mirror surface of the mirror surface roller are transferred to the substrate. When this pressure molding is performed, it is effective to insert the porous layer 22 between the roller 21 and the stamper 23 in order to more accurately and more faithfully transfer the fine concavo-convex pattern to the substrate.

When polycarbonate is used as the substrate material, the temperature of the polycarbonate extruded from the extruder 25 may be about 300 ° C., and the polycarbonate is set to 130 ° C. to 150 ° C. The roll stamper 20 and the mirror surface roller 27. A fine concavo-convex pattern is molded through the gaps between and. That is, the melted polycarbonate is rapidly cooled, and as a result, the viscosity is rapidly changed (increased).

From the above, how to suppress the change in the viscosity of the polycarbonate passing between the roll stamper 20 and the mirror-finished rolls 27 and 28 in order to improve the transfer. As a measure for this, it is effective to keep the surface temperature of the flexible stamper 23 of the roll-shaped stamper 20 as high as possible only during molding. Specifically, specifically, the mirror surface roll 21 and the flexible stamper 23 are kept.
It is effective to provide the heat insulating layer 22 between them. In particular,
In terms of the heat insulating effect, since the air has a low thermal conductivity, the porous layer containing the air acts as a very effective heat insulating layer.

The porous layer 22 is a layer having a uniform thickness containing, for example, air as closed cells or open cells in the matrix material. As this matrix material,
Since air having a low thermal conductivity exists as bubbles in the matrix material, there is no particular limitation in terms of thermal conductivity, and metals, ceramics, resins, etc. can be used, but low thermal conductivity This is the preferred embodiment. A resin material having heat resistance is suitable in terms of the above points, handleability, and processability. As a heat resistant resin material,
For example, polyether ether ketone (PEEK), polyether sulfone (PES), epoxy resin, Teflon resin, polyimide resin and the like can be used.

As the method of forming the porous layer 22, a method of mixing hollow fine particles into a matrix material, a method of sintering fine particles of a matrix, a method of mixing fine particles into a matrix material and then eluting the fine particles. Various methods such as a method of applying are applicable.

Roller 21 and flexible stamper 2
After allowing the porous layer 22 to intervene between the stamper 3 and the stamper 2
As a method of fixing 3 to the mirror surface roll 21, for example,
There is a method in which a fixing tool 24 is welded to both ends of the flexible stamper 23 by a laser or the like, a groove slightly larger than the fixing tool is formed in the mirror surface roll 21, and the fixing tool 24 is fitted and fixed in this groove. In addition to this, it may be fixed by screwing or a spring, and the means is not particularly limited as long as it can be fixed with good adhesion.

Using the roll-shaped stamper 20 produced in this way, as shown in FIG. 7 described above, a thermoplastic resin having optical anisotropy, for example, polycarbonate is extruded and molded to obtain a composite resin. It is possible to obtain a substrate having a small refraction and good transferability of the unevenness of the stamper. Further, the molded substrate is completed as an optical information recording medium through steps such as cleaning, recording layer deposition, bonding with a protective substrate, cutting into a predetermined shape, characteristic inspection, and packaging.

FIG. 8 is a schematic partial cross-sectional view showing an enlarged portion A of FIG. 5, showing a typical embodiment of the present invention. Mirror surface roller 21 and flexible stamper 2
3 has a sheet shape as the porous layer 22, for example, a porous plastic sheet can exert a heat insulating effect, and the thickness of the heat insulating layer is controlled by the thickness of the sheet in that it is a sheet shape. There is an advantage that you can.

FIGS. 9, 10, and 11 show various modes other than the mode shown in FIG. In FIG. 9, the porous layer 22 is laminated on the back surface of the stamper 23,
The aspect integrated with is shown. FIG. 10 shows a mode in which the porous layer 22 is laminated on the surface of the roller 21 and integrated with the roller 21. With these configurations, since the porous layer 22 is formed in advance during the production of the stamper or the roll, it is possible to reduce the mixing of dust and the like when the stamper is mounted, the defects of the molded sheet are reduced, and the quality and yield are reduced. improves. FIG. 11 shows an embodiment in which the porous layer 22 is formed on both the stamper back surface and the roll surface. 9 and 1
0, in the embodiment of FIG. 11, the porous layer 22 is a stamper 23.
Alternatively, since it is in close contact with the roll surface, the positional deviation of the porous layer occurs during molding, and the homogeneity of the molded sheet is less likely to be impaired. Particularly in the embodiment of FIG. 10, since the porous layer 22 is formed on the roll surface, it is not necessary to form the porous layer 22 for each stamper as compared with FIG. 9, which is advantageous when the stamper needs to be replaced.

As described above, the thermal conductivity of the porous layer containing the air layer for sheet formation using the roll stamper having the structure shown in FIGS. 8 to 11 is smaller than that of the metal roll and the metal stamper. , The porous layer exerts a very effective heat insulating effect during molding, the rapid temperature decrease of the thermoplastic resin during molding is suppressed, and as a result, the change in melt viscosity is also suppressed, and the uneven pattern of the substrate sheet to be molded Therefore, the transfer can be performed with extremely high precision. In the present invention, detachable means that, for example, a force for substantially separating is not required at the interface for attachment / detachment.

Hereinafter, the present invention will be described in more detail with reference to specific example data. In the following examples, the invention characterized by having a heat insulating layer inside the flexible stamper is shown as "Example A", and the invention characterized by having a porous layer is described as "Example A". Example B ".

<Example A-1> First of all, as follows:
A flexible stamper of the present invention having a heat insulating layer inside was manufactured.

In the step shown in FIG. 3A, the photoresist 7 (Az137) is formed on the glass substrate 6 such as soda lime glass.
0, made by Hoechst Japan Co., Ltd.), and spinner 3
It was applied to a film thickness of 000 Å. Then 9
Prebaking was performed at 0 ° C. for 30 minutes.

Next, in the step shown in FIG.
Laser exposure system (Mirror Projecior Mask Aligner
By using an exposure device such as MPA-1500, manufactured by Canon Inc.), a predetermined pattern (striped pattern) for a plurality of information recording media is exposed and developed with a developing solution (Az312MIF, manufactured by Hoechst Japan). A concave / convex fine pattern 7 ′ such as a tracking groove and an information pit was formed to obtain a glass master 8 for an optical card.

Next, in the step shown in FIG. 3C, as a pretreatment for forming a metal film by an electroforming method, a film forming apparatus such as a sputtering apparatus or a vapor deposition apparatus was used to conduct a conductive treatment. .. Further, a conductive film 9 was formed on the glass master 8 by forming a nickel film having a film thickness of 1000 to 2000 angstrom by a sputtering device.

Next, in the step shown in FIG. 3D, a metal film 13 was formed on the glass master 8 having the conductive film 9 by electroforming. In nickel sulfamate electroforming solution,
20 to 30 rpm for the glass master 8 on which the conductive film 9 is applied
While rotating at, the time integration value of the energizing current 150-30
100-200μ under 0AH (ampere hour) condition
m of nickel metal was deposited to form a metal film 13.

[0048] The composition herein using electroforming solution, nickel sulfamate tetrahydrate _{[Ni (NH 2 SO 3) 2} · 4
H ₂ O] = 500 g / l, boric acid [H ₃ BO _3] = 35
38 g / l, pit inhibitor = 2.5 ml / l.

Next, in the step shown in FIG. 3E, after the metal film 13 is polished to a thickness of 100 μm, the heat insulating layer 2 is formed.
Formed. Any material may be used for the heat insulating layer as long as it has a lower thermal conductivity than the metal film 13. In this example, a polyimide film was used and fixed at a predetermined position with an instant adhesive. The thickness of the polyimide film is preferably about 50 μm to 200 μm.

Next, in the step shown in FIG.
In the same manner as in the steps (C) and (D), the conductive treatment was performed again to form the metal film 13. This metal film 13
Polished.

Finally, in the step shown in FIG.
The conductive film 9 and the metal film 13 are integrated and simultaneously peeled off from the glass master 8 to remove the photoresist adhering to the surface, and laser cutting is performed to form a line.
And space: 9.5 μm / 2.5 μm, step: 2
A flexible stamper 1 provided with a heat insulating layer in which stripe guide grooves of 500 to 3000 angstroms were formed was obtained.

As the welding method, end welding is used in which the end portion of the flexible stamper is wound around the end portion of the fixture, and the end time is set to 5. by a YAG laser welding device (JK701, manufactured by Lumonix). 0 msec, assist gas = argon, frequency = 15 Hz, output = 5.
Fixing was performed under the conditions of 5J 80W and speed = 200 mm / min.

In this way, FIG. 1 (A) and (B)
A flexible stamper (with a fixing tool) having a heat insulating layer inside was completed. This flexible stamper was attached to a roller provided with a groove having substantially the same shape as that of the fixture in advance, and fixed while applying tension, whereby the roll-shaped stamper 5 shown in FIG. 2 was produced. Next, using this roll-shaped stamper 5, the RG shown in FIG.
Attempt was made to form roller / groove by the device. The molten resin of polycarbonate is extruded from the T die 10 of the extruder 11 at a resin temperature of 280 ° C. to 310 ° C., passed through between the roll stamper 5 and the mirror surface roller 12, and a minute uneven pattern of the roll stamper 5 is applied with a small pressure. Was transferred, the heat insulating layer of the polyimide film did not move or twist relatively freely even after 30 hours. As a result, a continuous sheet of information recording medium substrate in which a fine uneven pattern is transferred to the fine uneven pattern of the information recording medium substrate formed by the roller / groove molding method without adversely affecting transferability unevenness or the like. 14 could be manufactured.

<Example A-2> Steps (A) to (D)
Is the same as in Example A-1, and in the step (E), the metal film 1
After polishing 3 to a thickness of 100 μm, the heat insulating layer 2 was formed. An ultraviolet curable resin (2P resin) was used for the heat insulating layer. 2P resin (ThreeBond SS120) was applied and cured by bar coating. The curing is performed in a nitrogen atmosphere, and the thickness of the 2P resin is preferably about 50 μm to 200 μm, and in the present embodiment, it was formed to 50 μm. Next, the step (F) and the step (G) are also performed in Example A-1.
Same as.

As the welding method, the end welding is used in which the end portion of the flexible stamper is wound around the end portion of the fixing tool, and the on-time is set to 5. by a YAG laser welding device (JK701, manufactured by Lumonix Co., Ltd.). 0 msec, assist gas = argon, frequency = 15 Hz, output = 5.
Fixing was performed under the conditions of 5J 80W and speed = 200 mm / min.

Thus, FIG. 1 (A) and (B)
The flexible stamper with a heat-insulating layer (with a fixture) shown in Fig. 3 was completed. The flexible stamper provided with this heat insulating layer is attached to a roller having a groove having substantially the same shape as that of the fixing tool in advance, and is fixed while applying tension, whereby the roll-shaped stamper 5 shown in FIG.
Was produced.

Next, using this roll-shaped stamper 5,
Roller groove molding was tried using the RG apparatus shown in FIG. The molten resin of polycarbonate is extruded from the T die 10 of the extruder 11 at a resin temperature of 280 ° C. to 310 ° C., passed through between the roll stamper 5 and the mirror surface roller 12, and a minute uneven pattern of the roll stamper 5 is applied with a small pressure. Was transferred, the heat insulating layer of the polyimide film did not move or twist relatively freely even after 30 hours. As a result, a continuous sheet of information recording medium substrate in which a fine uneven pattern is transferred to the fine uneven pattern of the information recording medium substrate formed by the roller / groove molding method without adversely affecting transferability unevenness or the like. 14 could be manufactured.

<Comparative Example A-1> Steps (A) to (D)
In the same manner as in Example A-1, the metal film 13 was polished to a thickness of 200 μm to manufacture a flexible stamper having no heat insulating layer inside.

Next, welding with the fixture was performed under the same conditions as in Example 1 using a YAG laser welding device (JIK701, manufactured by Lumonix). This flexible stamper was attached to a roller provided with a groove having substantially the same shape as that of the fixture in advance, and fixed while applying tension to produce a roll stamper. A polyimide film was used for the heat insulating layer. Next, using this roll-shaped stamper 5, roller blube molding was tried by the RG device shown in FIG.

The molten resin of polycarbonate is extruded from the T die 10 of the extruder 11 at a resin temperature of 280 ° C. to 310 ° C., and the roll stamper 5 and the mirror surface roller 12 are extruded.
When the fine concave-convex pattern of the roll stamper 5 was transferred with a small pressure through the gap, defects were generated, and it was not possible to manufacture the continuous sheet 14 of the substrate for information recording medium on which the excellent concave-convex pattern was transferred. It was

Example B-1 A roll stamper shown in FIGS. 5 and 9 was produced as follows. A trapezoidal groove having an upper side of 10.05 mm, a lower side of 15.05 mm and a height of 5 mm was formed on a mirror-finished roller having an iron roller with a roll diameter of 300 mmφ plated with Cr and further mirror-finished to have a surface roughness of 0.1 μm.

Next, a glass master having a mirror surface of 300 mm square and a thickness of 10 mm was coated with a photoresist (AZ-130).
0, manufactured by Hoechst Japan Co., Ltd.) to a thickness of 300 nm, and an optical card pattern is formed in a region of 80 mm × 30 mm by a laser cutting machine, with a groove width of 3 μm and a pitch of 1
A large number of 2 μm pregrooves and concavo-convex patterns such as preformat signals are drawn on the glass master, and after the development process, concavo-convex patterns are formed, and Ni is sputtered to 100 n.
After film formation, electroforming was performed to deposit Ni of 200 μm, the back surface was mirror-polished to have a thickness of 150 μm and a surface roughness of 0.1 μm or less.

Next, a polyamide resin solution (LARC-T
PI varnish, manufactured by Mitsui Toatsu Chemicals, Inc., solid content: 30%, solvent: 50 parts of diethylene glycol dimethyl ether, was dispersed with 10 parts of crosslinked styrene-acrylic hollow fine particles (SX Synthetic Rubber Co., Ltd., SX863 (P)). Spray-coat the paint on the polished surface of the stamper, and
It was dried and cured at 50 ° C. for 5 hours to form a porous layer having a thickness of 0.5 mm.

This stamper is made of iron and has an upper side of 10 m.
A fixing tool having m, a lower side of 15 mm and a height of 5 mm was welded to a laser, and the fixing tool was inserted into a groove formed in a mirror surface roll to obtain a roll stamper. This is attached to a roll stand, and a polycarbonate (Teijin Kasei, L-1225) is extruded from an extrusion molding machine (Hitachi Zosen, SHT90), 3
m / min feed rate, die temperature 300 ° C, roll temperature 1
A sheet was formed into a sheet having a thickness of 0.4 mm and a width of 30 cm under the condition of 40 ° C. When the extruded substrate was measured, the value of birefringence was 10 to 20 nm in a single bath and showed little variation. The transferability of the uneven pattern was 97% or more, which was very good. The transferability is defined as the sectional area ratio of the concavo-convex pattern.

<Example B-2> A roll stamper shown in FIGS. 5 and 10 was produced as follows. The same paint as in Example B-1 was spray coated on the mirror surface roller, dried and cured to form a porous layer on the mirror surface roller.

Further, in the same manner as in Example B-1, the thickness 150
A fixing tool was welded to a stamper having a surface roughness of 0.1 μm or less and the roll stamper was fixed to the roller having a porous layer on the surface layer. This is attached to a roll stand, and an extrusion molding machine (Hitachi Zosen, SHT9
0) to polycarbonate (Teijin Kasei, L-1225)
Extrude 4m / min feed rate / die temperature is 300 ℃
・ Thickness 0.4mm, width 3 under conditions of roll temperature 150 ℃
The sheet was formed into 0 cm. When the extruded substrate was measured, the value of birefringence was 10 to 20 nm with a single bath.
There was little variation. Transferability of uneven pattern is also 97
% Was very good.

[0067]

As is clear from the above description, the inclusion of a heat insulating layer such as a polyimide film inside the flexible stamper can exert the following remarkable effects (1) and (2). ..

(1) A fine concavo-convex pattern of the information recording medium substrate molded by the roller / groove molding method is free from dust and foreign matter entering between the flexible stamper and the heat insulating layer such as a polyimide film. Can be accurately transferred without defects.

(2) Since the heat insulating layer such as the polyimide film does not move or twist relatively freely, the transferability unevenness is formed on the fine uneven pattern of the information recording medium substrate molded by the roller / groove molding method. It is difficult for defects such as Further, the flexible stamper itself does not deteriorate.

Further, as is clear from the above description, when the porous layer is interposed between the roll and the flexible stamper, when the uneven pattern of the stamper is formed in the thermoplastic resin having optical anisotropy. It is possible to provide a large amount of substrates for an optical information recording medium, which can alleviate molding distortion, have small birefringence, and have good transferability of precision patterns with high productivity. Further, since the sheet can be easily produced and attached, the roll-shaped stamper of the present invention is very useful in practice.

[Brief description of drawings]

FIG. 1A is a schematic view of a flexible stamper (with a fixing tool) provided with a heat insulating layer inside the present invention,
(B) is a schematic cross-sectional view taken along the cutting line AA ′.

FIG. 2 is a schematic cross-sectional view of a roll stamper in which a flexible stamper provided with a heat insulating layer inside is fixed to a roller according to the present invention.

FIG. 3 is a process explanatory view showing a method for manufacturing a flexible stamper provided with a heat insulating layer of the present invention.

FIG. 4 is a schematic cross-sectional view of an RG device using a roll stamper of the present invention.

FIG. 5 is a schematic view of a roll stamper having a porous layer of the present invention.

FIG. 6 is a schematic perspective view of a roll stamper having a porous layer of the present invention.

FIG. 7 is a schematic view of an apparatus using a roll stamper having a porous layer of the present invention.

FIG. 8 is a diagram showing an aspect of an enlarged portion of a portion A of FIG.

FIG. 9 is a diagram showing an aspect of an enlarged portion of a portion A of FIG.

FIG. 10 is a diagram showing an aspect of an enlarged portion of part A in FIG.

FIG. 11 is a diagram showing an aspect of an enlarged portion of a portion A of FIG.

[Explanation of symbols]

 1 Flexible Stamper 2 Heat Insulation Layer 4 Fixture 5 Roll Stamper 6 Glass Substrate 7 Photoresist 7'Uneven Fine Pattern 8 Glass Master 9 Conductive Film 10 T Die 11 Extruder 12 Mirror Roller 13 Metal Film 14 For Information Recording Medium Substrate Continuous sheet 15 Concavo-convex pattern 17 Roller 20 Roll stamper 21 Mirror surface roller 22 Thermal insulation layer 23 Flexible stamper 24 Fixing device 25 Extruder 26 Thermoplastic resin 27 Mirror surface roller 28 Mirror surface roller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location G11B 7/26 511 7215-5D 521 7215-5D // B29L 17:00 4F (72) Inventor Hayashi Hisanori 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kai Oka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Toshiya Yuasa Ota, Tokyo 3-30-2 Shimomaruko-ku, Canon Inc. (72) Inventor Hitoshi Yoshino 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (7)

[Claims] 1. A flexible stamper having a heat insulating layer having a lower thermal conductivity than the constituent material of the stamper inside. 2. A step of patterning unevenness on a substrate, a step of forming a conductive film on the pattern, a step of forming a metal film on the conductive film by electroforming, and a step of polishing the metal film. A step of forming a heat insulating layer on the polished metal film, a step of forming a conductive film on the heat insulating layer, a step of forming a metal film on the conductive film by electroforming, The method of manufacturing a flexible stamper according to claim 1, further comprising a step of polishing and a step of peeling the conductive film and the metal film together from the base material. 3. A roll-shaped stamper for forming irregularities on a thermoplastic sheet which is a substrate material of an optical information recording medium, the roll-shaped stamper having a heat insulating layer having a lower thermal conductivity than that of a constituent material of the stamper inside. A roll-shaped stamper, characterized in that a flexible stamper having a fixing member is provided on the surface of the roller by fitting the fixing member in the groove of the roller. 4. A substrate for an optical information recording medium, which comprises a step of forming irregularities on a thermoplastic sheet which is a substrate material of an optical information recording medium by a roll stamper comprising a roll and a flexible stamper provided on the surface of the roll. 2. The method for manufacturing an optical information recording medium substrate according to claim 1, wherein the flexible stamper has a heat insulating layer whose thermal conductivity is lower than that of the constituent material of the stamper inside. 5. A roll-shaped stamper comprising a roll and a flexible stamper provided on the surface of the roll, wherein the roll has at least one porous layer between the roll and the flexible stamper. Stamper. 6. One or more surfaces of the group consisting of the interface between the roll and the porous layer, the interface between the flexible stamper and the porous layer, and the porous interlayer surface are removable.
The roll stamper described. 7. A substrate for an optical information recording medium, which has a step of forming irregularities on a thermoplastic sheet which is a substrate material of an optical information recording medium by a roll stamper composed of a roll and a flexible stamper provided on the surface of the roll. 2. The method for manufacturing an optical information recording medium substrate according to claim 1, wherein the roll-shaped stamper has at least one porous layer between the roll and the flexible stamper.