JP2770843B2 - Method for manufacturing optical disc substrate and support member used for the same - Google Patents

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 an optical disk substrate, and more particularly, to a method for manufacturing an optical disk substrate by developing a photocurable resin between a stamper and a glass substrate and then irradiating ultraviolet rays. And a supporting member used for the method.

[0002]

2. Description of the Related Art A conventional method for manufacturing a substrate for an optical disk is as follows.
It is used in the manufacture of optical discs using glass substrates that can cope with large diameter and high speed rotation. 3 (a) to 3
(G) shows an example of a manufacturing process in a conventional method for manufacturing a substrate for an optical disk, and is a manufacturing process diagram of each stage in which a front view and a plan view corresponding to the front view are shown as one set.

In a conventional method of manufacturing a substrate for an optical disk,
First, as shown in FIG. 3A, a photocurable resin 32 is applied in a ring shape on the surface of a stamper 31 having an information pattern such as prepits and pregrooves. Stamper 31
Is made of a metal material such as Kickel.

Next, as shown in FIG. 3B, four claws 33 are placed on the surface of the stamper 31 and on the photo-curable resin 32.
Are arranged separately from each other, and a disk-shaped glass substrate 34 is placed on these claws 33. From this state, FIG.
As shown in (c), a direction in which the jig 35 is pressed against a center hole (central through hole) 34 a formed in the central portion of the glass substrate 34 to push the glass substrate 34 into the surface of the stamper 31. Load on the glass substrate 3
Curve 4 When bending the glass substrate 34,
The outer peripheral edge of the glass substrate 34 is locally supported by four claws 33.

After the glass substrate 34 is curved, FIG.
As shown in (d), the nail 33 is slowly opened in the outer peripheral direction of the glass substrate 34 to bring the glass substrate 34 into contact with the photocurable resin 32. Here, when the glass substrate 34 is brought into contact with the photocurable resin 32, the glass substrate 34
The reason for curving is to eliminate entrapment of air bubbles in the photocurable resin 32. By making the glass substrate 34 curved, mutual contact between the glass substrate 34 and the photocurable resin 32 is performed on the inclined surface of the glass substrate 34. For this reason, the initial contact area can be made smaller than when the contact is made without bending. Empirically, the smaller the contact area, the more the entrapment of air bubbles is suppressed.

After the pawl 33 has completely opened beyond the outer peripheral end of the stamper 31, the photo-curable resin 32 is developed as shown in FIG. When the development of the photo-curable resin 32 is completed, the photo-curable resin 32 is cured by irradiating ultraviolet rays 36 from above the glass substrate 34 as shown in FIG. Finally, as shown in FIG.
When the glass substrate 34 with the photocurable resin 32 is released from the mold, an optical disk substrate 37 is obtained.

The prior art (prior art 1) for manufacturing this type of optical disc substrate is disclosed in Japanese Unexamined Patent Publication No.
As disclosed in Japanese Patent No. 58745, during the resin injection, only the outer peripheral portion of the molding space is irradiated with light to cure the resin at the outer periphery to suppress the fluidity of the resin, and the resin overflows from the molding space, that is, burrs. A method for manufacturing an optical disk substrate that reduces the occurrence of blemishes is well known.

Further, as another prior art (prior art 2), as disclosed in Japanese Patent Application Laid-Open No. 62-293533, a mask having a step is arranged around an optical disk substrate, and 2. Description of the Related Art A method of manufacturing an optical disk is known in which an outer periphery of an optical disk substrate is applied to eliminate a relative displacement between a mask and a substrate so that burrs are not formed around the optical disk substrate.

[0009]

However, in the conventional method for manufacturing an optical disk substrate, when the glass substrate 34 is curved, the outer peripheral end of the glass substrate 34 is
3, there is a problem that the amount of bending is large at the supported position, and the amount of bending is small at the unsupported position on the outer peripheral edge of the glass substrate 34.

That is, at the position supported by the outer peripheral edge of the glass substrate 34, the amount of bending is large, the distance between the glass substrate 34 and the photocurable resin 32 is large, and even if the nail 33 is slowly opened, The contact between the glass substrate 34 and the photocurable resin 32 does not readily start. On the other hand, at a position where the amount of curvature of the glass substrate 34 is small, the distance between the glass substrate 34 and the photocurable resin 32 is also small. Contact begins.

As described above, if the timing of contact between the glass substrate 34 and the photo-curable resin 32 differs depending on the location, the developing speed of the photo-curable resin 32 becomes uneven, and in a location where contact starts early. The unfolding speed is slow in places where the unfolding speed is fast and starts slowly. In a place where the development is early, the development reaches the outer peripheral end of the glass substrate 34 before the entire development is completed. Furthermore, the photocurable resin 32 protrudes from the outer peripheral edge of the glass substrate 34 before the entire development is completed. The protruding photocurable resin 32 becomes burrs and remains on the glass substrate 34 after the curing process using ultraviolet rays.

Therefore, in the conventional method of manufacturing a substrate for an optical disk, there is a problem that burrs are easily generated on the outer peripheral end of the glass substrate 34 due to uneven development speed, and the yield is reduced.

Further, the manufacturing methods disclosed in the prior arts 1 and 2 have the same purpose in terms of preventing generation of burrs, but a manufacturing method different from the manufacturing method in which a plurality of claws 33 are opened is used. It is what we have adopted.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method of manufacturing a substrate for an optical disk while making the developing speed of the photocurable resin uniform and curving the glass substrate, and the burrs of the photocurable resin which cannot be avoided. An object of the present invention is to provide a method for manufacturing an optical disc substrate that suppresses occurrence and improves the yield.

[0015]

According to the present invention, a photocurable resin is applied to the surface of a stamper having an information pattern, and the glass member is supported by a supporting member which movably supports the glass substrate on the surface side of the stamper. Disposing a substrate on the photocurable resin, and opening the support member outward in the radial direction of the glass substrate while applying a load to the glass substrate and curving the glass substrate so as to protrude toward the surface side of the stamper. The glass substrate is lowered by contacting the glass substrate with the photocurable resin, and further, the photocurable resin is developed in a layer between the stamper and the glass substrate, and after the development is completed. An optical disk for curing the photocurable resin by irradiating ultraviolet rays from the glass substrate side, and finally releasing the stamper and the glass substrate to obtain an optical disc substrate. In the method for manufacturing a disk substrate, the support member has a plurality of support portions having an annular shape movable in the radial direction, each of the support portions having the same diameter as the outer diameter of the glass substrate, and wherein forming an arcuate slope to contact with the peripheral edge of the glass substrate, the supporting
No matter what height the radius of the part takes on the slope,
The radius of a plate, the glass substrate is uniformly curved while the supporting portion is in contact with the outer peripheral edge of the glass substrate, and the glass substrate and the photocurable resin are brought into contact with each other. A manufacturing method is obtained.

According to the present invention, in the support member used in the method for manufacturing an optical disk substrate, each of the support portions has the same diameter as the outer diameter of the glass substrate,
In addition, a support member used in a method for manufacturing an optical disc substrate, which has an arc-shaped slope contacting the outer peripheral end of the glass substrate, is obtained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing an optical disk substrate according to the present invention will be described below with reference to FIGS. 1 (a) to 1 (g) and FIG. 1 (a) to 1 (g) are manufacturing process diagrams showing each manufacturing step as a set of a front view and a plan view corresponding to this front view.

Referring to FIG. 1, in the method for manufacturing an optical disk substrate, first, as shown in FIG. 1A, a photocurable resin 2 is applied in a ring shape on the surface of a stamper 1 having an information pattern. . Next, as shown in FIG. 1B, a support member 3 is arranged on the stamper 1, and the glass substrate 4 is placed on the surface of the stamper 1 and the support member 3 arranged on the photocurable resin 2. . Here, as shown in FIG.
The four arc-shaped support parts 3a are combined with each other to form one annular body. These support parts 3
“a” comes into contact with and separates from each other by moving in the radial direction. The support portion 3a has an annular shape, and an inner surface serving as an inner peripheral surface thereof has an arc shape and is a slope 3b. It is important that the radius of the support portion 3a is equal to the radius R of the glass substrate 4 at any height of the slope 3b. That is, the outer peripheral edge of the glass substrate 4 is in contact with the inclined surface 3b in a state in which the support portions 3a are in contact with each other or approach each other, and open radially outward from a state of having an annular shape. However, after the support member 3 has completely opened outside the outer peripheral end of the stamper 1, the glass substrate 4
Is removed from the slope 3b.

In the embodiment, the annular shape is formed by the four support portions 3a. However, the present invention is not limited to the four support portions 3a.
The object of the present invention can be achieved by increasing or decreasing the number of a. In addition, the support portion 3a itself has an arc shape and a trapezoidal cross-sectional shape, but is not limited thereto. In this way, any shape may be used as long as the arc-shaped inclined surface 3b in contact with the outer periphery of the glass substrate 4 can be formed.

From the state where the glass substrate 4 is placed on the support member 3, as shown in FIG. 1C, a center hole (central through hole) 4a formed in the center of the glass substrate 4 is formed.
Then, the glass substrate 4 is bent by applying a load in a direction such that the glass substrate 4 is pushed into the stamper 1 using a jig 5 having a tapered outer peripheral surface. When the glass substrate 4 is curved, the outer peripheral end of the glass substrate 4 is supported by four support members 3 having an annular shape. At this time, when the glass substrate 4 is supported by using the support member 3, the glass substrate 4 has its outer peripheral end formed by the inclined surface 3 of the arc of each support portion 3 a of the support member 3.
Since it is supported over a wide range by the length of b, there is no difference in the amount of bending depending on the position on the circumference.

After the glass substrate 4 is bent by the jig 5, as shown in FIG.
Slowly open outward, that is, radially outward,
The glass substrate 4 and the photocurable resin 2 are brought into contact with each other while the outer peripheral end of the glass substrate 4 is in contact with the slope 3b of the support portion 3a. Here, as described above, the curved state of the glass substrate 4 is supported by the inclined surface 3b of the support portion 3a and is uniformly curved in the circumferential direction. Mutual contact is initiated almost simultaneously around the entire circumference.

After the support member 3 has completely opened outward beyond the outer periphery of the stamper 1, as shown in FIG. 3 (e), the photocurable resin 2 moves between the stamper 1 and the glass substrate 4. Wait for expansion to a predetermined area. At this time, as described above, since the contact between the photocurable resin 2 and the glass substrate 4 is started simultaneously over the entire circumference, there is almost no difference in deployment speed between locations.

Therefore, the development of the photocurable resin 2 is completed almost simultaneously in the entire region between the stamper 1 and the glass substrate 4. Therefore, the photocurable resin 2 does not protrude from the outer peripheral edge of the glass substrate 4.

When the development of the photocurable resin 2 is completed, FIG.
As shown in (f), the entire surface is irradiated with ultraviolet rays 6 from above the glass substrate 4 by a light source to cure the photocurable resin 2. Finally, as shown in FIG. 1 (g), the glass substrate 4 with the photocurable resin 2 is released from the stamper 1 to obtain the optical disk substrate 7. In the optical disk substrate 7 manufactured in this manner, since the photocurable resin 2 does not protrude outside the stamper 1 and the glass substrate 4 when the photocurable resin 2 is developed, burrs of the photocurable resin 2 are removed. Not at all.

[0025]

As described above, according to the method for manufacturing an optical disk substrate of the present invention, when the glass substrate is bent, the shape of the supporting member for supporting the glass substrate is the same as the outer diameter of the glass substrate. The curved surface of the glass substrate should be uniformly curved in the circumferential direction to eliminate differences in timing of contact between the glass substrate and the photocurable resin, and to make the development speed of the photocurable resin uniform. Thus, the effect of suppressing the occurrence of burrs is achieved.

Further, since the occurrence of burrs can be suppressed, the yield in the manufacture of an optical disc substrate can be improved.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a method of manufacturing a substrate for an optical disk according to the present invention, wherein (a), (b), (c), (d), (e),
(F) and (g) show each manufacturing process step, and are a set of a front view and a plan view corresponding to the front view, each of which is a manufacturing process diagram.

FIG. 2 is a partially sectional perspective view showing an embodiment of a support member used in the method for manufacturing an optical disc substrate of the present invention.

FIG. 3 shows an embodiment of a conventional method for manufacturing a substrate for an optical disk, wherein (a), (b), (c), (d), (e),
(F) and (g) show each manufacturing process step, and are a set of a front view and a plan view corresponding to the front view, each of which is a manufacturing process diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 31 Stamper 2, 32 Photocurable resin 3 Support member 3a Support part 3b Slope 4,34 Glass substrate 4a, 34a Center hole 5,35 Jig 6,36 Ultraviolet light 7,37 Optical disk substrate 33 Nail

Claims (2)

(57) [Claims] 1. A photo-curable resin is applied to the surface of a stamper having an information pattern, and the glass substrate is disposed on the photo-curable resin by a supporting member that movably supports the glass substrate on the surface side of the stamper. Then, while applying a load to the glass substrate and bending the glass substrate so as to protrude toward the surface side of the stamper, the support member is opened radially outward of the glass substrate to lower the glass substrate. And the glass substrate and the photocurable resin are brought into contact with each other,
The photocurable resin is developed into a layer between the stamper and the glass substrate, and after the development is completed, the photocurable resin is cured by irradiating ultraviolet rays from the glass substrate side, and finally the In a method for manufacturing an optical disc substrate, wherein a stamper and the glass substrate are separated from each other to obtain an optical disc substrate, the support member has a plurality of support portions having an annular shape movable in the radial direction. Each of the supporting portions has the same diameter as the outer diameter of the glass substrate, and forms an arc-shaped slope so as to be in contact with the outer peripheral end of the glass substrate .
No matter what height the radius takes on the slope, the glass substrate
A method of manufacturing a substrate for an optical disk, wherein the glass substrate is uniformly curved while the support portion is in contact with an outer peripheral end of the glass substrate, and the glass substrate is brought into contact with the photocurable resin. . 2. The support member used in the method for manufacturing an optical disc substrate according to claim 1, wherein each of the support portions has the same diameter as an outer diameter of the glass substrate, and is provided at an outer peripheral end of the glass substrate. A support member for use in a method for manufacturing an optical disk substrate, characterized in that the support member has an arcuate slope that is in contact therewith.