JPH08167178A - Production of master disk of stamper for optical recording medium - Google Patents

Abstract

PURPOSE: To provide a master disk for a stamper with a resin surface perfectly free from bubbles and defects and having a rugged pattern faithfully transferred from an original die by carrying out replica forming in a vacuum system after holding in the system for a certain time. CONSTITUTION: A certain amt. of 2P resin 3 is interposed between an original die 1 made of a glass substrate having a rugged pattern 1' and a porous glass substrate 2 and they are put in a transparent chamber 4. This chamber 4 is evacuated to a prescribed internal pressure from the exhaust port 5. After holding at the degree of vacuum for a prescribed time, the 2P resin 3 is cured by irradiation with UV from the substrate side 2 while keeping the degree of vacuum and then the original die 1 is peeled from the porous glass substrate 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a stamper master used for manufacturing a substrate for an optical recording medium, and more particularly to a photocurable resin (hereinafter abbreviated as "2P") during a step of forming a stamper master. 2) from the original type
It relates to a method of manufacturing a P replica.

[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. After that, the original mold and the replica substrate are overlapped to spread the 2P resin (hereinafter, referred to as 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 used. The substrate was peeled off, and a 2P resin replica was transferred and manufactured on the substrate.

3 (a) to 3 (c) illustrate this conventional process. First, fix the original mold 1 to the fixing plate 8,
A certain amount of 2P resin 3 is dispensed on the original mold 1 [FIG. 3 (a)]. After that, the glass substrates are overlapped and the 2P resin 3 is spread over the entire surface between the original mold 1 and the glass substrate 7, and the ultraviolet light (UV
Light) to cure the 2P resin 3 [FIG. 3 (b)].
After that, the cured 2P resin 3 (2
P replica) was manufactured [FIG.3 (c)].

[0004]

However, in such a conventional method, there is a problem that air bubbles are mixed in the resin at the time of stacking or spreading.

As a technique for solving this problem, Japanese Laid-Open Patent Publication No.
A method of performing spread in a vacuum as described in JP-A 1-213130, and further, JP-A-6-16848.
There is a method, as described in Japanese Patent Publication No. 2), in which a substrate is provided with a 2P resin injection port and the same exhaust port, and the 2P resin is injected in a vacuum by using its own weight to suppress air bubble mixing.

However, when the 2P resin is spread or injected in a vacuum as described above, bubbles may be generated due to a decrease in atmospheric pressure, and it may not be possible to prevent the inclusion of bubbles. Also,
Due to the heat generated during ultraviolet curing, the water contained in the 2P resin becomes bubbles, which causes bubble defects.

[0007]

According to the present invention, an original mold having a concavo-convex pattern and a substrate having a flat surface are opposed to each other, a 2P resin is sealed between the original mold and the substrate, and after photocuring. In a method for manufacturing a stamper master in which an original mold and a substrate are separated to form a replica of the original mold on the substrate surface, porous glass is used for the substrate, and at least the porous glass surface side is kept in a vacuum system for a certain time. By photo-curing in a state of being held at 2, it is possible to remove bubbles mixed during encapsulation (injection) of the 2P resin or bubbles in which water contained in the 2P resin is vaporized due to heat generation during photocuring. Even if it cannot be completely removed, bubbles existing at the interface of the 2P resin / original mold can be moved toward the interface of the 2P resin / porous glass substrate.
It is possible to manufacture a stamper master that has no bubble defects on the surface of the P resin and faithfully transfers the original concave-convex pattern.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. (Embodiment 1) FIG. 1 is a diagram showing well the features of the present invention. That is, between the original mold 1 and the porous glass substrate 2 made of a glass substrate or the like having the uneven pattern 1 ′,
A certain amount of the 2P resin 3 is sandwiched and left in the transparent chamber 4 of 0.1 Torr or less for 1 hour or more, and then the 2P resin 3 is UV-cured. The porous glass substrate 2 used here may be one that is impermeable to the liquid 2P resin 3 and has gas permeability. This makes it possible to manufacture a stamper master that has no bubble defects on the surface of the 2P resin (concave pattern surface) after UV curing and that accurately transfers the original mold concavo-convex pattern.

Original mold 1 having a pattern area of 250 × 250 mm, 300 × 300 mm and a thickness of 10 mm
And, 2P resin 3 (manufactured by Nippon Kayaku Co., Ltd., trade name INC-118) was dispensed between a porous glass substrate 2 (made by Corning Co., Ltd., Vycor ^(R) average pore size 40 angstroms) having a thickness of 10 mm and a size of 340 × 340 mm, and the original type. 1
And the porous glass substrate 2 were overlapped with each other to spread the 2P resin 3. The hole diameter of the multi-hard glass substrate is preferably 100 angstroms or less. The laminate of the original type / uncured 2P resin / porous glass substrate thus obtained is placed in the transparent chamber 4 as shown in FIG. Next, the air in the transparent chamber 4 was exhausted from the exhaust port 5, the internal pressure was set to 0.1 Torr, and the vacuum degree was maintained for 2 hours. The air bubbles mixed in at the time of spreading were completely removed. Next, while maintaining the above-mentioned degree of vacuum, ultraviolet rays were irradiated from the porous glass substrate side to cure the 2P resin. After that, when the original mold 1 and the porous glass substrate 2 were peeled off, there were no bubbles on the surface of the 2P resin 3 and a 2P replica in which the concavo-convex pattern of the original mold 1 was faithfully transferred was obtained. The degree of vacuum and the standing time in the vacuum system are 1 Tor
It is preferably r or less and 1 hour or more. (Example 2) The same original mold 1 as in Example 1 and a porous glass substrate 2 of 340 x 340 mm and 10 mm in thickness having an injection port (φ10 mm) arranged outside the pattern effective area (Born, manufactured by Corning Inc., average) After making the pore diameter of 40 angstrom) face each other through the spacer material 6 (polyethylene terephthalate film) having a thickness of 80 μm, the uncured 2P resin 3 was injected. The spacer material 6 was arranged at the outer peripheral edge of the original mold 1 with a width of 5 mm.
The laminate of the original type / uncured 2P resin / porous glass substrate thus obtained is placed so that the porous glass substrate side can be maintained in a vacuum system as shown in FIG.
Next, the air in the transparent chamber 4 is exhausted from the exhaust port 5,
The internal pressure was set to 0.1 Torr, and the vacuum was maintained for 2 hours. The bubbles mixed during the injection were completely removed. Next, while maintaining the above degree of vacuum, the porous glass substrate side was irradiated with ultraviolet rays to cure the 2P resin 3.
After that, when the original mold 1 and the porous glass substrate 2 were peeled off, there were no bubbles on the surface of the 2P resin, and a 2P replica in which the concavo-convex pattern of the original mold was faithfully transferred was obtained.

[0010]

As described above, according to the present invention,
After encapsulating the uncured 2P resin between the original mold and the porous glass substrate, by holding at least the porous glass substrate side in the vacuum system for a certain period of time, it is possible to remove air bubbles mixed in during encapsulation of the 2P resin. Further, by curing the 2P resin in a vacuum state, it is possible to remove bubbles generated by heat generation during curing or prevent bubbles from remaining at the interface between the original mold and the 2P resin. Therefore, on the surface of the 2P resin after UV curing, there is an effect that a 2P replica that faithfully transfers the original concave-convex pattern without bubble defects can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a manufacturing method in a first embodiment.

FIG. 2 is an explanatory diagram showing a manufacturing method according to a second embodiment.

FIG. 3 is an explanatory view showing a manufacturing method in a conventional example.

[Explanation of symbols]

 1 Original type 1'Uneven pattern 2 Porous glass substrate 3 2P resin 4 Transparent chamber 5 Exhaust port 6 Spacer material 7 Glass substrate 8 Fixing plate 9 Bubbles

Claims (1)

[Claims] 1. In the step of producing an original type replica having a preformat and electroforming this to produce a stamper, porous glass is used at the time of producing the replica, and at least the porous glass surface side is constant. A method of manufacturing a stamper master for an optical recording medium, characterized in that the replica molding is carried out while being held in a vacuum system for a time.