JP2530696B2 - Optical recording medium duplication method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an optical recording medium capable of optically reproducing information, and more specifically, an optical recording produced by a method called 2P (photo polymerization) method. Regarding the body

[Conventional technology]

2 and 3 are diagrams for explaining a conventional example of a method of copying an optical recording medium.

In order to achieve high density recording, it is necessary for the optical recording material to form an uneven optical information recording pattern on the optical recording material base material. Therefore, some molding methods have been proposed, but a method called 2P (photo polymerization) method, which has extremely high transfer accuracy of a fine information recording pattern, has been actively studied.

FIG. 2 is a diagram showing a process of copying a typical optical recording medium by the 2P method. The outline of the 2P method will be described below with reference to FIG.

The mold 1 shown in FIG. 2 (a) has unevenness on the surface corresponding to the information recording pattern. In the 2P method, first,
An ultraviolet-curable resin 2 is applied on the mold 1 as shown in FIG. 2B, and a base material 3 is superposed on the mold 1 as shown in FIGS. Place. Then, the resin 2 is irradiated with ultraviolet rays to cure the resin 2 as shown in FIG. 6E, and then the mold 1 is peeled off as shown in FIG. The information recording pattern is transferred and molded.

As a method of applying the ultraviolet curable resin, when the base material 3 is stacked on the curable resin 2 as shown in FIG. 3A, the curable resin 2 is also applied on the base material 3 beforehand. , The curable resins 2 are brought into contact with each other as shown in FIG.
There is also a method of preventing the inclusion of air bubbles by curing the resin and peeling off the mold 1 (Japanese Patent Laid-Open No. 63-81639).

[Problems to be Solved by the Invention]

However, in the conventional 2P molding method such as the former method, the resin applied to the mold such as the stamper spreads over time, and the contact area increases when the base material is stacked on the resin. Therefore, air bubbles tend to be caught between the surfaces contacting each other, and the air bubbles are mixed in the resin layer, which causes problems such as a decrease in molding yield and an increase in error rate.

Further, as described in Japanese Patent Laid-Open No. 63-81639, the latter method in which a resin is applied onto a substrate and the resin is prevented from spreading due to its own weight has a drawback in its application method itself. Furthermore, since the resin 2 is applied on the base material 3, there is a problem that the number of steps is increased, which is not preferable.

The present invention is to solve the above problems, and an object thereof is to provide a smooth convex curved surface of a base material when the base material is first contacted with a curable resin having a viscosity of 100 to 5000 cps. Point contact or line contact with the convex part of the curable resin that has a smooth convex curved surface, and then the point or line contact so that air bubbles do not mix during the stacking process. It is an object of the present invention to provide a method of duplicating an optical recording medium which has a low error rate and a high yield by preventing bubbles from being mixed into the resin by gradually expanding the contact area of the substrate from the state.

[Means for solving the problem]

Therefore, the present invention, in the duplication of the optical recording medium by the 2P method, when the substrate is first contacted with a curable resin having a viscosity of 100 to 5000 cps, the convex of the substrate having a smooth convex curved surface. Part is point-contacted or line-contacted with the convex part of the curable resin having a smooth convex curved surface applied on the mold, and then the base material so that air bubbles are not mixed in during the stacking process. Are stacked so that the area of contact with the curable resin gradually expands from the contact state.

[Action]

In the method of copying an optical recording medium of the present invention, a substrate and 100 to 5
At the first contact with a curable resin having a viscosity in the range of 000 cps, the convex portion of the smooth convex curved surface of the substrate is point-contacted with the convex portion of the curable resin having a smooth convex curved surface, Alternatively, it is possible to prevent air bubbles from being mixed into the resin by making a line contact and then stacking the base material on the resin such that the contact area is gradually expanded from this state.

〔Example〕

 Hereinafter, embodiments will be described with reference to the drawings.

FIG. 1 is a diagram for explaining one embodiment of a method of copying an optical recording medium according to the present invention.

In the replication method of the present invention, as shown in FIG. 1A, first, a curable resin 2 having an information recording pattern on its surface, for example, a mold 1 such as a stamper having a smooth convex curved surface. Apply. Next, after the base material 3 curved so as to form a smooth convex curved surface as shown in FIG. 3B is brought into contact with the resin 2, the contact area is expanded as shown in FIG. Go on. That is, since the convex portion of the smooth convex curved surface of the base material 3 and the convex portion of the smooth convex curved surface of the resin 2 come into contact with each other, the initial contact between the base material 3 and the resin 2 becomes a point or a line. The contact area gradually expands from the open state.

In this way, since the base material 3 and the resin 2 are in point or line contact with each other, it is possible to prevent bubbles from being mixed in unlike the conventional method in which a large area is contacted at once. That is, in the conventional method, since the base material 3 and the resin 2 are in surface contact from the beginning and a large area is in contact at a time, bubbles are likely to be mixed, but according to the method of the present invention, such surface contact does not occur, Does not come into contact with a large area. Moreover, since the contact area is gradually increased from the point or line contact, it is possible to prevent bubbles from entering. In addition, a conventional example shown in FIG.
Since there is no step of applying the resin 2 on the base material 3 as in Japanese Patent No. 1639), the processing steps can be simplified and the processing becomes easy. Therefore, the base material 3 can be stacked on the mold 1 while preventing bubbles from being mixed in the resin 2 by the above operation. A state without air bubbles is obtained by irradiating ultraviolet rays from the side of the base material 3 stacked in this way to cure and integrate the resin 2 and peel off the mold 1 as shown in FIGS. Thus, the information recording pattern on the mold 1 can be transferred and molded onto the base material 3.

Here, the curvature of the base material 3 is preferably such that the contact area is as small as possible within the range where the base material is not destroyed.

The substrate used in the present invention needs to be a flexible material, and plastic resins such as polymethylmethacrylate (PMMA), polycarbonate (PC), polyester, epoxy, polyolefin and polystyrene are desirable.

Further, as the resin used in the present invention, a general ultraviolet curable resin and an electron beam curable resin are listed, but after the resin is applied on the mold, a viscosity such that the degree of spread is small with time (for example, A resin composition having a clay range of 100-5000 cps) is desirable.

 The present invention was carried out as follows.

First, a stamper (20 cm) 1 having a concave and convex optical information recording pattern with a pitch of 1 μm and a step of 800 Å on the surface 1
0.5 cm ³ of an ultraviolet curable resin (trade name: SS-120, company name: ThreeBond) 2 was dropped in the upper center by a dispenser. Then, a polycarbonate resin base material having a thickness of 15 cm and a thickness of 0.4 mm was bent to R = 25 cm, and was placed on the resin 2 so as to be convex downward. At that time, it was placed so that the center of the base material 3 was in contact with the center of the resin 2. Then gradually expand the contact surface,
The base material 3 was completely stacked on the stamper 1. Further, ultraviolet rays were irradiated from the side of the substrate 3 to cure the resin 2, and the cured and integrated resin 2 layer and the substrate 3 were separated from the stamper 1 to duplicate the optical recording body.

Microscopic inspection of the duplicated product carried out as described above showed that no bubbles were observed and a good optical recording medium was obtained.

〔The invention's effect〕

As described above, according to the method for reproducing an optical recording medium of the present invention, when the base material and the curable resin having a viscosity of 100 to 5000 cps are first contacted with each other, the smooth convex shape of the base material is obtained. The convex portion of the curved surface is point-contacted or line-contacted with the convex portion of the smooth convex curved surface of the curable resin to prevent the inclusion of air bubbles. By stacking the materials so that the contact area is gradually expanded, it is possible to duplicate the optical recording body in which no air bubbles are mixed in the resin. As a result, duplication of an optical recording medium having a low error rate is possible without increasing the number of steps, and the duplication yield is improved, and the production cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of an optical recording medium duplicating method according to the present invention, and FIGS. 2 and 3 are diagrams for explaining a conventional example of an optical recording medium duplicating method. . 1 ... Mold, 2 ... Resin, 3 ... Base material.

Claims (1)

(57) [Claims] 1. A curable resin is dropped on a mold having an information recording pattern on its surface, a base material is stacked on the mold, and then the curable resin is cured to integrate the base material and the curable resin. Then, in the optical recording medium duplication method of duplicating the resin layer provided with the information recording pattern on the base material by releasing the integrated base material and the curable resin from the mold, the base material is cured. It has a smooth convex curved surface toward the mold resin, and the curable resin applied on the mold has a viscosity of 100 to 5000 cps and a smooth convex surface on the mold toward the base material. Has a curved surface, and when the base material is first contacted with the curable resin, the convex portion of the smooth convex curved surface of the base material is replaced by the convex portion of the smooth convex curved surface of the curable resin. Point contact or line contact with the above, and then above to prevent air bubbles from entering during the stacking process. The method of replicating an optical recording medium, characterized in that the wood is spread gradually the area of contact with the curable resin from the contact state to a product location.