JP3104198B2 - Stamper manufacturing apparatus and stamper manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Table of Contents] The present invention will be described in the following order. Technical field to which the invention pertains Prior art (FIG. 6) Problems to be solved by the invention (FIGS. 7 to 11) Means for solving the problems Embodiments of the invention (FIGS. 1 to 5) Effects of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stamper manufacturing apparatus and a stamper manufacturing method, and more particularly to a stamper manufacturing method and a stamper manufacturing method suitable for forming a center hole in a stamper having a concavo-convex pattern according to a recording signal.

[0003]

2. Description of the Related Art Conventionally, when an optical disk such as a compact disk (CD) or a laser disk is manufactured, a stamper which is a mold for the mold is prepared in advance and injection molding is performed using the stamper. It is common to make a large number of optical disks from one stamper.

[0004] The stamper is formed by the process shown in FIG. That is, first, a photoresist 2 is applied on one surface (hereinafter, this surface is referred to as a super-mirror surface) 1A of the glass plate 1 which has been extremely polished (FIG. 6A), and the photoresist 2 is irradiated with a laser beam hν. After recording a signal by exposing (FIG. 6 (B)), the pattern is developed to form a concavo-convex pattern on the super mirror surface 1A of the glass plate 1 according to the signal recorded on the photoresist 2 (FIG. 6B). 6
(C)).

Subsequently, a conductive film layer 3 is formed on the surface of the concavo-convex pattern by sputtering, chemical plating, or the like (FIG. 6D). Further, after a plating layer 4 having a predetermined thickness is formed on the conductive film layer 3 by electric plating or the like (FIG. 6).
(E)), the stamper portion 5 composed of the conductive film layer 3 and the plating layer 4 is peeled off, and the photoresist or the like attached to the pit surface is washed away (FIG. 6 (F)). Finally, the final stamper 7 is obtained by forming the center hole 6 by punching.

[0006]

The punching die for forming the center hole 6 is configured as shown in FIG. The punching die 10 places and holds the stamper 5 on a table-shaped female die 12 provided on a fixed platen 11 such that the concave and convex pit surface faces upward. The holding force at this time is obtained by the magnetic force of the magnet provided on the stamper mounting surface of the female mold 12. The placement and holding is performed after the stamper is positioned at a predetermined placement position while checking the positioning marks formed on the concave and convex pit surfaces by a sensor (not shown). Here, the mounting is performed so that the uneven pit surface faces upward in order to avoid damage to the uneven pit surface due to contact with the mounting surface.

A movable platen 15 connected to a hydraulic cylinder 14 via a piston rod 13 is provided above the stamper 5, and the movable platen 15 is moved up and down by the hydraulic cylinder 14. A cylindrical male die 16 extending in the direction of the stamper 5 is provided on the lower surface of the movable platen 15, and a blade portion is formed at the tip of the male die 16. On the lower surface of the movable platen 15, an annular holding portion 17 surrounding the male die 16 is attached to one end of a coil spring 18.

In this configuration, the punching die 10 lowers the male die 16 together with the movable platen 15 from above the stamper 5 mounted and held at a predetermined position on the female die 12. Then, the pressing portion 17 first comes into contact with the stamper 5 and presses the stamper 5 by the elastic force of the coil spring 18. When the movable platen 15 further descends, the male die 16 contacts the stamper 5 to form a center hole by punching out the center region of the stamper 5, and fits into a punched hole 12 </ b> A formed in the female die 12. Thus, the center hole 6 (FIG. 6) is formed in the stamper 5. It should be noted that the punching waste is removed via the punching hole 12A.

After the center hole 6 is formed by the punching die 10, the stamper 7 has a shape as shown in FIG. As is clear from the figure, in the center hole of the stamper 7, due to the punching, sagging occurs on the side of the uneven pattern surface, and punching burrs occur on the surface opposite to the uneven pattern surface. The stamper 7 thus produced is mounted on an injection molding machine, as shown in FIG. 9, and the resin such as polycarbonate is injected into the concave and convex pit side by the injection molding machine, whereby the disk substrate 20 is formed. It is formed. Here, the center hole is used as a positioning portion when attaching the stamper 5 to the injection molding machine.

Thereafter, as shown in FIG. 10, a reflective film layer 21 is formed on the disk substrate 20 removed from the injection molding machine so as to cover the concave and convex pit surfaces.
1, a protective layer 22 is formed on the protective layer 22, and a printed layer 23 on which the title of the optical disk is displayed by screen printing is formed on the protective layer 22 to obtain a final optical disk. .

However, as is apparent from FIG. 10, burrs 20A are formed on the disk substrate 20 at the time of injection molding due to sagging of the center hole of the stamper 7, and the burrs 20A adversely affect subsequent processes. Problem. For example, the burrs 20A may be caught on the screen mesh during screen printing, so that the screen mesh may be damaged.

As shown in FIG. 11, in a so-called laminated optical disk 30 in which two optical disks are laminated to obtain twice the amount of recorded information, an adhesive 24 is used. When the two burrs 20A are bonded to each other, the burrs 20A of each of the disk substrates 20 collide with each other.
The distance between the optical disks changes accordingly, and as a result, there is a problem that a desired bonded optical disk 30 cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to propose a stamper manufacturing apparatus and a stamper manufacturing method capable of manufacturing a stamper which does not generate burrs which may cause a problem on an optical disk substrate. Things.

[0014]

According to the present invention, there is provided a stamper manufacturing apparatus for forming a center hole in a stamper such that the stamper has an uneven pit surface on which an uneven pit is formed. Holding means 41, 43, 44, and punching means 42, 45, 4 for punching the center area of the stamper 5 corresponding to the center hole from the uneven pit surface toward the back surface of the uneven pit surface.
6, 48 are provided. As a result, stamper 5
In the center hole of, punch burrs occur on the side of the uneven pit,
In addition, dripping occurs on the back surface of the uneven pit surface. Therefore, when injection molding is performed using this stamper 5, since the sagging occurs on the concave and convex pit surface side of the disk substrate 60, the problem due to the generation of burrs can be avoided.

Further, according to the present invention, in the stamper manufacturing method for forming a center hole in the stamper 5, a force is applied from the surface of the two surfaces of the stamper 5 opposite to the surface on which the concave and convex pits are formed. Thus, the central region of the stamper 5 corresponding to the center hole is punched in the direction of the surface on which the uneven pits are formed. As a result, in the center hole of the stamper 5, punch burrs are formed on the concave and convex pit surface side, and sag is generated on the back surface of the concave and convex pit surface. Therefore, when injection molding is performed using this stamper 5, since the sagging occurs on the concave and convex pit surface side of the disk substrate 60, the problem due to the generation of burrs can be avoided.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 40 denotes a punching die which forms a center hole of the stamper as a whole, and applies a force from the surface of the stamper opposite to the surface on which the concave and convex pits are formed. By providing the stamper, the center region of the stamper corresponding to the center hole is punched in the direction of the surface on which the uneven pits are formed. As a result, in the punching die 40, the direction in which sagging and punching burrs occur is reversed from the conventional direction.

The punching die 40 is provided with a cylindrical male die 42 on a fixed platen 41. A doughnut-shaped mounting table 43 formed so as to surround the male mold 42 is connected to the fixed platen 41 via a coil spring 44. Thus, the mounting table 43 is connected to the fixed platen 41 by the coil spring 44 so as to be able to move up and down. The mounting surface of the mounting table 43 is made of magnet,
The mounted stamper 5 is held by magnetic force.

A movable platen 47 connected to a hydraulic cylinder 46 via a piston rod 45 is provided above the stamper 5.
Is moved up and down by a hydraulic cylinder 46. The movable platen 47 is provided with a female mold 48 extending in the direction of the stamper 5, and the female mold 48 descends together with the movable platen 47 to press the upper surface of the stamper 5 (that is, the uneven pit surface).

In the above configuration, when the stamper 5 is positioned and mounted on the mounting table 43 at a predetermined position, the punching die 40 holds the stamper 5 at that position by the magnetic force of the magnet. At this time, the stamper 5 is placed so that the concave and convex pit surface faces upward. Next, the movable platen 47 is lowered by driving the hydraulic cylinder 46. As a result, the tip of the female mold 48 comes into contact with the upper surface of the stamper 5.

Here, the height of the mounting table 43 is such that the lower surface of the stamper 5 mounted and held is
Slightly away from the tip of the
It is selected so that it comes into contact with the tip of the. Then, when the female mold 48 descends while abutting on the stamper 5, the stamper 5 and the mounting table 43 are integrally pressed down.

Then, the male mold 42 comes into contact with the lower surface of the stamper 5, and a center hole is made in the stamper 5 by the blade formed at the tip of the male mold 42. At this time, the male mold 42 fits into the punched hole 48A of the female mold 48. In this way, the punching die 40 punches out the center hole from the surface of the stamper 5 opposite to the uneven pit surface. It should be noted that the punching waste is removed through the punching hole 48A.

FIG. 2 shows the shape of the center hole formed by the punching die 40 according to the embodiment. As is apparent from the drawing, the sag is formed on the surface opposite to the concave and convex pit surface, and the punching burr is formed on the concave and convex pit surface side, contrary to the conventional stamper. When this stamper 50 is attached to an injection molding machine, it becomes as shown in FIG. FIG. 4 shows a reflective film layer 61 and a disk substrate 60 formed by injection molding.
The state where the protective film layer 62 and the printing layer 63 are formed is shown.

As is clear from FIG. 4, no burrs (FIG. 10) are formed on the disk substrate 60 as in the prior art.
As a result, when performing screen printing, the screen mesh is not damaged. In addition, as shown in FIG. 5, when the two optical disks are bonded with an adhesive 64 to form a bonded disk 70, there is no burr on the disk substrate 60, so that there is no gap between the two optical disks. Can be maintained at a constant value, and a good bonded optical disk 70 can be obtained.

According to the above structure, the center hole of the stamper 5 is formed by applying a force from the surface opposite to the concave and convex pit surface and punching in the direction of the concave and convex pit. The occurrence of burrs at 60 can be prevented.

In the above-described embodiment, the stamper manufacturing apparatus according to the present invention includes the holding means 41, 43, 44 for holding the stamper 5 so that the uneven pit surface on which the uneven pits are formed is the upper surface, and the center hole. Has been described, the punching means 42, 45, 46, and 48 for punching the center region of the stamper 5 corresponding to the above from the uneven pit surface toward the back surface of the uneven pit surface, but the present invention is not limited to this. In short, if the center region of the stamper corresponding to the center hole can be punched from the uneven pit surface toward the back surface of the uneven pit, it can be widely applied to various other stamper manufacturing apparatuses. That is, in the embodiment, the holding means includes a base 41, a mounting table 43 for mounting and holding the stamper 5 such that an opening of a predetermined shape is formed at a position corresponding to the center hole, and the uneven pit surface is on the upper surface. Mounting table 43
And a resilient means 44 which is connected to the base 41 so as to be able to move up and down. A punching means is provided at a position facing the back surface of the concave and convex pit surface of the stamper 5 through an opening formed in the mounting table 43. A male member 42 having a projection having the same diameter as the center hole, and a female member 48 provided at a position facing the concave and convex pit surface of the stamper 5 and into which the male member 42 fits.
Moving means 4 for moving the female member 48 in the direction of fitting into the male member 42 and in the direction away from the male member
5 and 46, the holding means and the punching means may have various other structures.

[0027]

As described above, according to the present invention, a force is applied to the stamper corresponding to the center hole by applying a force from the surface of the stamper opposite to the surface on which the concave and convex pits are formed. By punching out the central region of the substrate in the direction of the surface on which the concave and convex pits are formed, it is possible to realize a stamper manufacturing apparatus and a stamper manufacturing method capable of preventing the occurrence of burrs which may cause a problem on an optical disc substrate. .

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration of a stamper punching die according to an embodiment.

FIG. 2 is a side view showing a shape of a center hole formed by a stamper punching die of the embodiment.

FIG. 3 is a schematic side view showing a state where a stamper manufactured by a stamper punching die according to the embodiment is attached to an injection molding machine.

FIG. 4 is a cross-sectional view showing a shape of an optical disk made based on a stamper manufactured by a stamper punching die according to the embodiment.

FIG. 5 is a cross-sectional view showing the shape of a laminated optical disk manufactured based on a stamper manufactured by a stamper punching die according to the embodiment.

FIG. 6 is a cross-sectional view for explaining a stamper forming step.

FIG. 7 is a side view showing a configuration of a conventional stamper punching die.

FIG. 8 is a side view showing the shape of a center hole formed by a conventional stamper punching die.

FIG. 9 is a schematic side view showing a state in which a stamper manufactured by a conventional stamper die is attached to an injection molding machine.

FIG. 10 is a cross-sectional view showing the shape of an optical disk made based on a stamper manufactured by a conventional stamper punching die.

FIG. 11 is a cross-sectional view showing the shape of a bonded optical disk made based on a stamper manufactured by a conventional stamper punching die.

[Explanation of symbols]

5, 7, 50 ... stamper, 6 ... center hole, 1
0, 40 ... Stamper punching die, 11, 41 ... Fixed platen, 12, 48 ... Female type, 12A, 48A ... Punching hole, 13, 45 ... Piston rod, 14, 46 ...
Hydraulic cylinder, 15, 47 ... Movable platen, 16, 4
2 ... male type, 17 ... holding part, 18, 44 ... coil spring, 20, 60 ... optical disk board, 20A ... burr, 21, 61 ... reflective film layer, 22, 62 ... protective film Layers, 23, 63: printing layer, 24, 64: adhesive, 3
0, 70 ... lamination type optical disk, 43 ... mounting table.

Claims (3)

(57) [Claims] In a stamper manufacturing apparatus for forming a center hole in a stamper, the stamper has an uneven pit surface on which an uneven pit is formed.
The holding means for holding the upper surface and the center area of the stamper corresponding to the center hole,
Punching from the uneven pit surface to the back side of the uneven pit surface
Stamper manufacturing characterized by comprising punching means
apparatus. 2. The holding means has a base and an opening having a predetermined shape at a position corresponding to the center hole.
So that the uneven pit surface is the upper surface.
A mounting table for mounting and holding the damper, and elastic means for connecting the mounting table to the base so as to be able to move up and down.
Has, the hitting Nukite stage, the stamper through the opening formed in the mounting table
Is provided at a position facing the back surface of the uneven pit surface,
A male member consisting of a protrusion having the same diameter as the center hole, and a stamper provided at a position facing the concave and convex pit surface.
A female member into which the male member fits, a direction in which the female member is fitted into the male member, and
Moving means for moving in a direction away from the male member
Stamper according to claim 1, characterized in that it comprises bets
Manufacturing equipment. (3) Stan forming a center hole in the stamper
In the manufacturing method An uneven pit is formed on the two surfaces of the stamper.
By applying force from the opposite side to the
The center area of the stamper corresponding to the center hole
Punched in the direction of the surface where the convex pit was formed This
And a stamper manufacturing method.