JPH10228674A - Disk substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity without injuring a master disk when mold material and a disk substrate are peeled off from the master disk by providing a tapered angle on the outer peripheral end part of the disk substrate. SOLUTION: In manufacture that the disk substrate 1 is stuck to the master disk 3, and a photosetting or thermosetting resin layer 5 is formed between them, and after the resin layer 5 is set by irradiating the resin layer 5 with ultraviolet rays, the substrate 1 and the resin layer 5 are peeled off from the master disk 3 also, and a recording medium is obtained, a taper of 5-60 deg. is provided on the outer peripheral end part of the substrate 1, and a engagement pawl 11 of an engagement member 10 is abutted on the tapered part, and the disk substrate is engaged surely. When it is peeled off from the master disk 3, by turning a movable member 6 and peeling off it while abutting on the engagement pawl 11, the peeling off becomes possible with small force. At this time, when the taper angle is not more 5 deg., the engagement pawl becomes easy to come off, and further, when it exceeds 60 deg., the probability that a crack and a break occur in the disk substrate 1 at a peeling time exists.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk substrate capable of improving the productivity of a recording medium such as an optical disk or a molded product and increasing the recording density.

[0002]

2. Description of the Related Art Conventionally, for example, in an optical disk such as a CD-ROM or other recording medium, a mold (stamper) for manufacturing a substrate is formed in a process called mastering, and an injection molding method is performed using the mold. Is manufactured by molding a resin-made disk substrate and forming a recording film, a reflection film, and the like on the disk substrate.

It is necessary to form an irregular shape on the recording surface of the disk substrate in accordance with the recording data. At present, a mold having a shape for molding the irregular shape on its surface is made of Ni. A disk substrate is formed by using a metal master formed by plating, injecting a molten resin into a mold of the master by an injection molding method, and cooling and solidifying the resin.

On the other hand, instead of the injection molding method described above,
A UV curable resin is applied to the surface of either the master or the resin-made disk substrate having translucency, and the master and the disk substrate are bonded together via the UV curable resin. In this state, ultraviolet light is applied from the disk substrate side. Irradiating the resin to cure the resin, and then peeling the disk substrate together with the cured resin layer from the master disc (JP-A-56-37836, JP-A-1-180328, etc.).

As described in Japanese Patent Application Laid-Open No. 4-31833, the surface of a semiconductor wafer made of Si or the like is not formed by a master made of a metal such as Ni as described above, but by a known photolithography method. There is also proposed a method of using a master formed by fine processing.

[0006]

In the conventional optical disk manufacturing method using the injection molding method, the relationship between the viscosity of the molten resin and the dimensions of the inner surface structure of the mold, the mixing of bubbles, and the heating in the injection molding method are described. Transferability may be insufficient due to warping and distortion due to resin, sink of resin during cooling, etc., and there is a limit in molding accuracy, so a serious obstacle to increasing the recording density of the optical disk There is a problem that becomes.

On the other hand, in a method in which a resin is interposed between a master and a disk substrate, and the resin is cured and then peeled off, the resin having good transferability but being cured and in close contact or adhesion is removed. There is a problem that it is difficult to peel off from the master and productivity is reduced.

Further, when a master made of a thin and brittle material such as a semiconductor wafer such as Si is used as described above, there is a problem that the master is likely to be damaged due to stress during peeling. is there. Therefore, it is difficult to effectively use the semiconductor fine processing technology, and it is difficult to increase the recording density of an optical disc to be copied.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to realize the manufacture of a disk substrate capable of improving the productivity of a recording medium such as an optical disk and increasing the recording density. Can be performed with good productivity without damaging the master, when the master and the disk substrate are bonded together via the molding material and the disk substrate is peeled off from the master together with the molding material after the molding material is cured. It is to provide a disk substrate.

[0010]

In order to solve the above-mentioned problems, a disk substrate of the present invention is obtained by laminating an original master processed into a predetermined surface shape and the disk substrate via a molding material. A taper angle for peeling the disk substrate with the molding material remaining on the surface of the disk substrate after curing the material is provided at an outer peripheral end of the disk substrate.

Further, in the disk substrate according to the present invention, the taper angle is 5 degrees or more and 60 degrees or less.

[0012] Further, the disk substrate of the present invention is obtained by laminating an original master processed into a predetermined surface shape and the disk substrate via a molding material, and curing the molding material, and thereafter, on the surface of the disk substrate. An uneven portion for peeling off the disk substrate with the molding material left is provided at an outer peripheral end of the disk substrate.

Further, the disk substrate of the present invention is characterized in that the molding material is made of a photocurable resin or a thermosetting resin.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Next, an embodiment according to the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a disk substrate 1 of the present invention.
FIG. The portion of θ shown in FIG. 1 corresponds to the taper angle. As the disk substrate, a resin substrate such as amorphous polyolefin, polycarbonate, acrylic, or the like, or a glass substrate or other materials is used. FIG. 2 is a side view of the peeling mechanism of the disk substrate 1. In the peeling mechanism, a base 4 for holding the master 3 on the base 2 is attached. A master 4 made of a silicon substrate is held and fixed on the surface of the base 4. The master 3 is formed by processing various materials such as a nickel substrate, a glass substrate, and a resin substrate in addition to the silicon substrate. This type of master 3 is thin and brittle, so it is easily broken. On the other hand, it is widely used as a semiconductor, such as a silicon substrate, and therefore has high market distribution. There is an advantage that it can be applied as it is. In particular, the one formed by exposing the applied photoresist to a pattern corresponding to the recording data is preferable from the viewpoint of increasing the recording density. For example, as described in Japanese Patent Application Laid-Open No. Hei 4-31833, the master 3 is formed with a resist mask by a well-known photolithography technique and then subjected to an etching process. An uneven shape is formed.

The surface of the base 4 has its surface irregularities limited to several μm or less by polishing or the like. Due to this smoothness, the adhesion to the master 3 can be improved and the suction force can be increased, and the distortion of the master 3 can be suppressed, so that the master 3 is less likely to be damaged even when an external stress is applied. Thus, it is possible to increase the accuracy of the surface structure formed on the disk substrate, and thus the surface accuracy of the disk substrate onto which the structure is transferred.

On the surface of the master 3, a disk substrate 1 made of a transparent resin is interposed via a resin layer 5 made of an ultraviolet curable resin.
Is fixed. A resin layer 5 is applied to the disc substrate 1 in a previous step, and the applied surface is adhered to the surface of the master 3 and irradiated with ultraviolet rays to form the resin layer 5.
Has been cured.

A generally plate-shaped movable member 6 is arranged above the base 4, the master 3, and the disk substrate 1. The movable member 6 is rotatably mounted on the pedestal 2 about a rotation shaft 8 by being pivotally supported by a shaft support 7 fixed to the upper surface of the pedestal 2. A slider 9 is attached to the distal end side of the movable member 6, and a locking member 10 attached to the distal end of the slider 9 can be protruded and retracted in the plate surface direction of the movable member 6. A locking claw 11 is provided at the lower end of the locking member 10 and extends in the direction of the plate surface of the movable member 6, and the tip of the locking claw 11 contacts the outer peripheral end of the disk substrate 1. By providing the locking claw 11 having an upward tapered surface corresponding to the tapered surface of the outer peripheral end of the disk substrate 1, the engagement between the locking claw 11 and the disk substrate 1 can be ensured. Further, by providing the locking claws 11 at a plurality of positions with respect to the disk substrate 1 or by increasing the contact area between the locking claws 11 and the disk substrate 1, the separation can be further reliably performed. . Movable member 6
Has a built-in suction holding structure (not shown) so that the disk substrate 1 is sucked and held at the time of peeling.
When the disk substrate 1 is peeled, the resin layer 5 is peeled off at the interface between the resin layer 5 and the master 3 with the resin layer 5 fixed to the bottom surface of the disk substrate 1. This is because the material is selected in advance so that the adhesion between the disc substrate 1 and the resin layer 5 is greater than the adhesion between the master 3 and the resin layer 5. Further, in order to further increase the adhesion between the disk substrate 1 and the resin layer 5, the surface of the disk substrate 1 may be subjected to a surface activation treatment such as a plasma treatment.

The optical disk according to the present invention is manufactured by the following steps. First, the disk substrate 1 is subjected to a surface activation process by a plasma processing process. Next, a photocurable resin is applied to the surface. As this coating method, there is also a method of coating the surface of the master 3 instead of the disk substrate 1, or the coating may be performed on both the master 3 and the disk substrate 1. Further, as the resin material constituting the resin layer 5, it is necessary to use a resin material suitable as a final product, and it is not limited to the above-described photocurable resin, and as a result, a fine structure can be transferred to some extent. If so, a resin such as a thermosetting resin or a thermoplastic resin or another material may be used. In particular, when a photo-curing resin or a thermosetting resin is used, it is a general-purpose resin, and high productivity can be obtained and cost reduction can be realized. Further, the transferability of a fine pattern is very excellent. Next, the disk substrate 1 and the master 3 are bonded together, and the resin is spread over the entire surface.
The resin layer 5 is formed. Next, the resin layer 5 is irradiated with ultraviolet rays.
To cure. Finally, peeling is performed using the above peeling mechanism. In the peeling step, first, the movable member 6 is rotated on the disk substrate 1 to suck the disk substrate. next,
The locking claw 11 is moved so as to contact the outer peripheral end of the disk substrate 1. Then, the movable member 6 is rotated in the peeling direction while the locking claw 11 is in contact with the outer peripheral end of the disk substrate 1, and the disk substrate 1 and the resin layer 5 are peeled from the master 3. By using this method, peeling can be performed with a smaller peeling force.

Further, in order to perform peeling by this method, the taper angle of the disk substrate 1 is an important parameter. FIG. 3 is a correlation diagram showing the relationship between the taper angle and the yield in peeling. If the taper angle is less than 5 degrees, the locking claw 11 tends to come off from the outer peripheral end of the disk substrate 1 at the time of peeling, which causes a drop in productivity. Also,
If the taper angle exceeds 60 degrees, the disc substrate 1 is not peeled when peeling.
Since the force concentrates on the outer peripheral edge of the disk substrate 1, cracks or chips may occur in the disk substrate 1. Also, the disk substrate 1
Also, there is a problem that the device is easily damaged during handling. When the taper angle is 5 degrees or more and 60 degrees or less, more preferably, when the taper angle is 10 degrees or more and 60 degrees or less,
Peeling can be performed with good productivity without damaging the master. Further, the taper angle may be formed at a part of the outer peripheral end as shown in FIG. 4, and the effect is the same. After peeling, the outer peripheral end may be processed into a desired shape.

The shape of the outer peripheral end portion may be any shape other than the taper, as long as it has irregularities. The larger the contact area with the locking claw, the more stable peeling becomes possible. 5, 6, and 7
FIG. 1 shows an example of a side view of the disk substrate of the present invention.

In this embodiment, an optical disk is taken as an example, but the same applies to other recording media such as a magnetic disk, or molded products.

[0022]

As described above, the present invention has the following effects.

An original disk processed into a predetermined surface shape and the disk substrate are bonded to an outer peripheral end portion of the disk substrate via a molding material, and after the molding material is cured, the master is hardened on the surface of the disk substrate. A disk substrate capable of improving productivity and increasing recording density of a recording medium such as an optical disk or a molded product by providing a taper angle or an uneven portion for peeling the disk substrate in a state where a molding material is left. Can be manufactured. Further, when the master and the disk substrate are bonded together via a molding material, and the disk substrate is peeled off from the master together with the molding material after the molding material is cured, the production can be performed without damaging the master and with high productivity. A disk substrate can be provided.

[Brief description of the drawings]

FIG. 1 is a side view of a disk substrate according to the present invention.

FIG. 2 is a side view showing a disk substrate peeling mechanism according to the present invention.

FIG. 3 is a correlation diagram showing the relationship between the disk substrate and the yield according to the present invention.

FIG. 4 is a side view of the disk substrate according to the present invention.

FIG. 5 is a side view of a disk substrate according to the present invention.

FIG. 6 is a side view of a disk substrate according to the present invention.

FIG. 7 is a side view of the disk substrate according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disc board 2 Base 3 Master 4 Base 5 Resin layer 6 Movable member 7 Shaft support 8 Rotating shaft 9 Slider 10 Locking member 11 Locking claw

Claims (5)

[Claims] 1. A disk substrate, wherein an original master processed into a predetermined surface shape and the disk substrate are bonded together via a molding material, and after the molding material is cured, the molding material is formed on the surface of the disk substrate. A disk substrate characterized in that a taper angle for peeling the disk substrate is provided at an outer peripheral end of the disk substrate in a state where the disk substrate is left. 2. The disk substrate according to claim 1, wherein said taper angle is not less than 5 degrees and not more than 60 degrees. 3. The disk substrate according to claim 1, wherein the molding material is made of a photocurable resin or a thermosetting resin. 4. A disk substrate, wherein an original master processed into a predetermined surface shape and the disk substrate are bonded via a molding material, and after the molding material is cured, the molding material is formed on the surface of the disk substrate. A disk substrate, wherein an uneven portion for peeling the disk substrate is provided at an outer peripheral end of the disk substrate while leaving the disk. 5. The disk substrate according to claim 4, wherein the molding material is made of a photo-setting resin or a thermosetting resin.