JPH08161774A - Manufacture of stamper master disk for optical recording medium - Google Patents

Abstract

PURPOSE: To prevent a 2P resin from generating a lifting or a shrinkage after the 2P resin has been hardened by a method wherein, when a cell is formed via spacer, a filler such as glass beads or the like is filled into its inside space and the 2P resin is injected and hardened. CONSTITUTION: A cell 4 which comprises a gap is formed via an original mold 1 which comprises an uneven pattern such as a pit, a groove or the like and via a spacer material 3 at the outer circumferential edge part of a substrate having a flat surface. Then, a filler 7 is filled into its inside space, a photoreactive resin is injected, and the resin is hardened. In this case, when the 2P resin is hardened, the contraction of its volume can be reduced to a minimum at a time when it is changed from a liquid phase to a solid phase. Thereby, the flatness of the surface of a 2P replica can be brought close to the flatness of the original mold as far as possible. In addition, it is possible to prevent that the hardened 2P resin lifts to peel off the original mold 1 and that the 2P resin generates a shrinkage due to contraction in the in-plane direction of the cell 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a stamper master used for manufacturing a substrate for an optical recording medium, and more particularly to a photocurable resin (hereinafter referred to as "2
Abbreviated as “P”) to produce a 2P replica from the original mold.

[0002]

2. Description of the Related Art Conventionally, as a general method of manufacturing a stamper master for an optical recording medium, a 2P resin is applied or dropped (hereinafter referred to as dispense) on at least one of an original mold and a replica substrate, and thereafter, The original mold and the replica substrate are overlapped to spread the 2P resin (hereinafter referred to as a spread), and in that state, light is irradiated from at least one of the two to cure the 2P resin, and then the original mold and the replica substrate are combined. Peel off the 2 on the substrate
The P resin replica was manufactured by transfer.

4 (a) to 4 (c) illustrate the steps of this conventional method. First, the original mold 1 is fixed to the fixing plate 11, and the 2P resin 8 is dispensed on the original mold 1 by a predetermined amount [FIG. 4 (a)]. Then, the glass substrate 2 is overlaid, the 2P resin 8 is spread over the entire surface between the original mold 1 and the glass substrate 2, and ultraviolet light (UV light) is irradiated from the glass substrate 2 to cure the 2P resin 8 [FIG.
(B)]. Then, the cured 2P resin 8 is applied to the glass substrate 2
Hardened by peeling from the original mold 1 with 2P
Resin 10 (2P replica) was manufactured [Fig. 3
(C)].

However, in such a conventional method, there are problems that air bubbles are mixed in the resin at the time of stacking or spread, or 2P resin is squeezed out by dispensing an excessive amount of 2P resin. It was
Regarding the protrusion, for example, as shown in FIG. 4C, a protrusion of the 2P resin may be formed at the end of the cured 2P resin 10. If these projections are left as they are, they may be chipped in the subsequent process and become dust and adhere to the pattern part of the 2P replica, or adhere to the end part of the original mold and be used again for manufacturing the 2P replica. There is a problem that it becomes a projection of the original type. Therefore, it is conceivable to apply a release agent to the edges of the original mold and the glass substrate, or use a masking agent to peel off the 2P resin that has hardened to form burrs. However, the removed burrs may adhere to the 2P replica or the pattern surface of the original mold and cause defects, which is also undesirable.

As a conventional technique for solving these problems,
As disclosed in Japanese Patent Laid-Open No. 61-213130, there is a method for preventing the protrusion by spreading in a vacuum to prevent air bubbles from entering and providing a 2P resin leakage prevention wall on the outer peripheral edge portion. However, when such a prevention wall is provided, it is difficult to accurately control the supply amount of the 2P resin to be dispensed, and when the supply amount is insufficient, the 2P resin may not be supplied to the uneven pattern portion. Further, in the case of an excessive amount, protrusion occurs beyond the prevention wall.

In addition to the above-mentioned problems, the conventional method has a so-called "floating" in which the 2P surface is distorted due to curing shrinkage of the 2P resin, and the cured 2P resin peels from the original mold at the prevention peripheral edge portion. There is also a problem that "sinks" occur. As a conventional technique for solving such a problem, there is a method, as described in JP-A-1-196748, for reducing floating and sinking by interposing an elastic body made of rubber or spring between the original mold and the substrate. is there.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art.
An object of the present invention is to provide a method for manufacturing a stamper master in which a 2P replica free from distortion, floating, and sinking, which prevents shrinkage during curing of P resin, is formed.

[0008]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and its gist is to provide an original die having a concavo-convex pattern such as pits and grooves and a spacer material on the outer peripheral edge of a substrate having a flat surface. A method of manufacturing a stamper master for an optical recording medium, characterized in that a cell having a gap is formed through the resin, a photo-curable resin is encapsulated after a filling material is filled in the internal space, and the resin is photo-cured. is there.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of the shape of a cell used in the method for manufacturing a stamper master according to the present invention. FIG. 1 (a) is a plan view of the cell and FIG. 1 (b) is a sectional view taken along the line AA. As shown in FIG. 1, an original mold 1 having a concavo-convex pattern 1 ′ such as pits and grooves and a glass substrate 2 having a flat surface are opposed to each other, and a cell 3 is provided on the outer peripheral edge portion thereof with a spacer material 3 having a predetermined thickness. 4 is formed.

At this time, the filling material 7 is filled in the internal space of the cell 4. The filler 7 is granular, and its particle size must be equal to or less than the thickness of the spacer material 3. The injection port 5 is provided with a through hole outside the effective area 6 of the original mold 1, and the through hole is used as a 2P resin injection port. The through hole may be provided in the glass substrate.

The method of injecting the 2P resin may be a method of utilizing the differential pressure between the internal pressure and the external pressure of the cell 4 (internal pressure <external pressure), a method of injecting by utilizing the weight of the 2P resin, and the like. .

After the injection of the 2P resin 8 into the cell 4 is completed, as shown in FIG.
As shown in Fig. 2, the uncured 2P resin in the cell 4 is irradiated with UV light from the original mold 1 side to be cured (see Fig. 2).
(A), (b)) The original mold 1 and the glass substrate 2 are separated and separated to obtain a stamper master having the 2P replica 10 formed on the glass substrate 2 (FIG. 4).
(C), (d)).

As described above, 2P in the present invention
In the replica manufacturing method, the filling material 7 is placed in the inner space of the cell 4.
2P resin 8 is filled with and is cured (because the volume of the 2P resin to be cured is drastically reduced), the volume contraction that occurs when the liquid phase of the 2P resin is changed from the liquid phase to the solid phase is minimized. Can be deterred. Therefore, the flatness of the 2P replica surface is as close as possible to the flatness of the original type. Furthermore, there is an effect that "floating" that the cured 2P resin is separated from the original mold 1 at the outer peripheral edge portion and "sinking" that shrinks in the in-plane direction of the cell 4 can be prevented.

[0015]

EXAMPLES The present invention will now be described in more detail based on examples.

Example 1 300 × 3 with a pattern area of 250 × 250 mm
An original die with a flatness of 10 μm having an injection port outside the effective pattern area of 00 mm and a glass substrate of 340 × 340 mm, a spacer material (polyethylene terephthalate) with a width of 5 mm and a thickness of 60 μm is arranged on the outer peripheral edge of the original die, and a cell is formed. Glass beads (manufactured by Tokai Kogyo Co., Ltd., average particle diameter 45 μm, maximum particle diameter 55 μm) were filled inside to obtain a cell. 2P resin (Nippon Kayaku Co., INC11
8) was injected. Next, this cell was irradiated with ultraviolet rays from the original mold side to cure the 2P resin (FIG. 2,
(A), (b)). At this time, it is preferable that the 2P resin is UV-cured with the original mold having the concavo-convex pattern facing upward because the glass beads are less likely to project onto the cured 2P surface because of the specific gravity of the glass beads (2P resin <glass beads). "Floating" around the spacer material after 2P curing
"Hike" was not recognized. Peel off the original mold and the glass substrate and remove the spacer material (Fig. 2 (c),
Then, (d)) and the flatness of the surface of the cured 2P replica was measured. As a result, it was 11 μm, and there was almost no distortion with respect to the original mold. By UV curing, a 2P replica in which the original concave-convex pattern was faithfully transferred with very little distortion was obtained.

Example 2 A flatness of 10 μm and a pattern area of 250 × 250 m
m except that an original mold of 300 mm × 300 mm and a glass substrate of 340 mm × 340 mm having an injection port outside the pattern area were prepared and a glass balloon (average particle diameter 45 μm, maximum particle diameter 55 μm) was used as a filler. The same as in Example 1. A schematic view of the UV curing → peeling step of the injected 2P resin is shown in FIGS. At this time, from the relationship of the specific gravities of the 2P resin and the glass balloon (2P resin> glass balloon), it is more preferable to perform UV curing with the original mold having the concavo-convex pattern facing down because the glass balloon is less likely to project onto the cured 2P surface. . 2P
Neither "lifting" nor "sinking" was observed around the spacer material after curing. The flatness of the surface of the 2P replica after peeling was 11 μm, and there was almost no distortion with respect to the original mold. A 2P replica was obtained in which the original concave-convex pattern with very little distortion due to UV curing was faithfully transferred.

[0018]

As described above, according to the present invention, when a cell is formed between an original mold and a glass substrate through a spacer material, a filling material such as glass beads is filled in the internal space of the original mold and the 2P resin. By injecting and curing
Curing shrinkage of P can be suppressed and "floating" of the outer peripheral part after curing
You can prevent "sinks". Further, there is an effect that a 2P replica in which the surface precision and the concavo-convex pattern of the original mold are faithfully transferred can be obtained.

[Brief description of drawings]

1A and 1B are a plan view and a sectional view taken along the line AA of the cell showing an example of the shape of the cell used in the method for manufacturing a stamper master according to the present invention.

FIG. 2 is a process diagram 1 showing an example from 2P implantation to 2P replica creation.

FIG. 3 is a process diagram showing another example from injection of 2P to production of a 2P replica.

FIG. 4 is a process diagram showing a method of manufacturing a stamper master in which a 2P replica is formed by a conventional dispense spread method.

[Explanation of symbols]

 1 Original type 1'Concavo-convex pattern 2 Glass substrate 3 Spacer material 4 Cell 5 Injection port 6 Effective area 7,7 'Filler material 8 2P resin 9 UV light 10 2P replica 11 Fixed plate

Claims (2)

[Claims] 1. A cell having a gap is formed at an outer peripheral edge of a substrate having a flat surface and an original die having a concavo-convex pattern such as pits and grooves, and a filling material is filled in the inner space thereof. A method for manufacturing a stamper master for an optical recording medium, which comprises encapsulating a post-photocurable resin and photocuring the resin. 2. The method of manufacturing a stamper master according to claim 1, wherein the filler is glass beads or glass balloons.