JP2893720B2 - Method for manufacturing optical information recording medium - Google Patents

Description

The present invention relates to a method for manufacturing an optical information recording medium, and is preferably applied to a method for manufacturing an optical disk such as a compact disk (CD).

B. Summary of the Invention The present invention relates to a method for manufacturing an optical information recording medium, comprising: an information recording layer formed on a signal pattern layer of a support substrate;
A resin is filled between the light transmitting layer having a thickness of 200 [μm] and cured after the resin is applied, so that the light transmitting layer is adhered to the supporting substrate, so that the information recording layer is recorded from the light transmitting layer side. And / or by manufacturing a reproducible optical information recording medium.

C Prior Art Conventionally, in this type of optical disk manufacturing method, a 2P (photo polymerization) method for duplicating an optical disk using an ultraviolet curable resin has been proposed (Japanese Patent Application No. 61-111199). And Japanese Patent Application No. 61-146731).

That is, in the 2P method, first, as shown in FIG. 2 (A), a disk stamper 1 on which a fine uneven pattern is formed according to a recording signal and a glass substrate 2 having a thickness of about 1.2 [mm]. Before the ultraviolet irradiation, the ultraviolet curable resin 3 in a liquid state is sandwiched, and the ultraviolet curable resin 3 is pressed between the stamper 1 and the glass substrate 2 by pressing from the glass substrate 2 side using a pressing roller (not shown) or the like. Fill.

Subsequently, as shown in FIG. 2 (B), after the ultraviolet light L _UV emitted from the light source UV from the glass substrate 2 side becomes an ultraviolet lamp or the like is irradiated to cure the ultraviolet curable resin 3,
As shown in FIG. 2 (C), the ultraviolet curable resin 3 is peeled off from the stamper 1 together with the glass substrate 2.

Thereby, as shown in FIG. 2 (D), the signal pattern transfer layer 3A having a thickness of several [μm] to several tens [μm] obtained by transferring the fine concavo-convex pattern of the stamper 1 onto the glass substrate 2 is obtained.
To form

Thereafter, as shown in FIG. 2 (E), the aluminum reflective layer is formed from the pit side of the transfer glass substrate 4 on which the signal pattern transfer layer 3A is formed by using, for example, sputtering, vacuum evaporation or spin coating. After forming 5,
A protective layer 6 is formed of a resin material on the aluminum reflective layer 5 side, and thus an optical disk 7 on which a pit pattern corresponding to the concavo-convex pattern of the stamper 1 is formed can be manufactured.

D Problems to be Solved by the Invention By the way, in the optical disk device using the optical disk 7 manufactured as described above, in order to increase the recording density, the wavelength of the laser beam L applied to the optical disk 7 is changed. In addition to shortening, the numerical aperture (NA (numerica
l aperture)) has been increased.

However, the above-mentioned optical disk 7 has an objective lens 8 disposed on the glass substrate 2 side, irradiates a laser beam L through the objective lens 8, and reads a signal based on the reflected light reflected by the aluminum reflective layer as a result. Has been made.

Therefore, between the objective lens 8 and the aluminum reflective layer 5, the thickness of the signal pattern transfer layer 3A (= several μm to several tens μm) is equal to the thickness of the glass substrate 2 (= 1.2 mm). At least, the high NA of the objective lens 8
Was difficult in practice.

To solve this problem, the glass substrate 2 of the optical disk 7
It is conceivable to reduce the thickness of the
Scratches and dust on the surface of the optical disk 7 have a large effect on the aluminum reflective layer 5 and increase the warpage of the glass substrate 2, thereby increasing the skew of the optical disk 7.

In addition, in such a case, according to the manufacturing method, the birefringence is expected to increase, and the durability of the aluminum reflective layer 5 around environmental changes may be deteriorated. It was still insufficient.

The present invention has been made in view of the above points, and has as its object to propose a method for manufacturing an optical information recording medium capable of manufacturing an optical information recording medium suitable for high-density recording in a simple process.

E. Means for Solving the Problem In order to solve such a problem, in the present invention, a signal pattern layer 3A made of an ultraviolet curable resin having a fine uneven pattern transferred onto the support substrate 2 is formed, ~ 200
[Μm] and a cover glass 10 for transmitting a laser beam radiated from outside onto the signal pattern layer 3A.
Pressure bonding was performed on the signal pattern layer 3A with the 11A interposed therebetween.

F action Between the information recording layer 5 of the supporting substrate 2 and the light transmitting layer 10 having a thickness of 50 to 200 [μm], the resin 11 is filled and cured, and the light transmitting layer 10 is bonded to the supporting substrate 2. By doing so, it is possible to manufacture an optical information recording medium 12 which can record and / or reproduce information on and from the information recording layer 5 from the light transmitting layer 10 side.

G Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a method for manufacturing an optical disk according to the present invention,
First, as shown in FIG. 1 (A), the 2P method (FIG. 2 (A) to FIG.
(D) On the signal pattern transfer layer 3A of the transfer glass substrate 4 on which the signal pattern transfer layer 3A is formed, the aluminum reflection layer 5 is formed by a technique such as sputtering.

Subsequently, a thin cover glass 10 having a thickness of 50 to 200 [μm] is arranged on the transfer glass substrate 4 on the side of the aluminum reflective layer 5, and a few centipoise to a few centimeters are provided between the transfer glass substrate 4 and the thin cover glass 10. After sandwiching a liquid ultraviolet curable resin 11 having a viscosity of 10 centipoise, pressure is applied from the thin cover glass 10 side using a pressure roller (not shown), so that the transfer glass substrate 4 and the thin cover glass 10 are pressed. The ultraviolet curable resin 11 is filled.

Subsequently, as shown in FIG. 1 (B), it is irradiated with ultraviolet light L _UV emitted from the light source UV to cure the ultraviolet curing resin 11, a transparent UV adhesive layer 11A made of the number of thick [μm] is formed As a result, the thin cover glass 10 is transferred to the transfer glass substrate 4.
Glue to

Thus, as shown in FIG. 1 (C), an optical disk 12 capable of reproducing the pit pattern of the aluminum reflective layer 5 is manufactured through the thin cover glass 10 and the transparent UV adhesive layer 11A.

When the optical disk 12 manufactured as described above is irradiated with the laser beam L through the objective lens 13 arranged on the side of the thin cover glass 10, the objective lens 13 is thinner than the aluminum reflective layer 5. The thickness can be approached to an interval obtained by adding the thickness of the transparent UV adhesive layer 11A (= several μm) to the thickness of the cover glass 10 (= 50 to 200 μm).

Thus, in the optical disk device using the optical disk 12, the objective lens 13 can be closer to the aluminum reflective layer 5 as compared with the conventional one, so that the objective lens 13 having a higher NA can be used. As a result, an optical disk 12 capable of higher density recording than before can be obtained.

According to the above method, the resin 11 is filled between the aluminum reflective layer 5 and the thin cover glass 10 on the transfer glass substrate 4 and then cured to bond the thin cover glass 10 to the transfer glass substrate 4. As a result, an optical disk 12 capable of reproducing the aluminum reflective layer 5 from the thin cover glass 10 side can be manufactured. In this way, the distance between the objective lens 13 and the aluminum reflective layer 5 is significantly reduced as compared with the conventional case. By shortening the length of the optical disk, the NA of the objective lens 13 can be increased, and thus a method of manufacturing the optical disk 12 capable of manufacturing the optical disk 12 capable of high-density recording / reproduction with a simple process can be realized.

Further, according to the above-described method, the cover glass 10 is adhered to the aluminum reflective layer 5 on the side of the objective lens 13, so that the light is excellent in flatness and transparency, hardly permeates moisture, and resistant to scratches and dirt. Discs can be manufactured.

Further, according to the above-described method, since a glass substrate similar to the conventional glass substrate is used as the substrate, it is possible to prevent surface runout and skew from occurring.

Further, according to the above-mentioned method, the pit pattern of the aluminum reflective layer 5 is reproduced through the thin cover glass 10 and the transparent UV adhesive layer 11A, thereby producing the optical disk 12 capable of effectively removing the occurrence of birefringence. it can.

In the above-described embodiment, the case where a glass substrate is used as the substrate has been described. However, the present invention is not limited to this, and it is not necessary to irradiate laser light from the substrate side. The same effect as in the above-described embodiment can be realized by using the substrate.

Further, in the above-described embodiment, the case where the ultraviolet curable resin 11 is filled between the transfer glass substrate 4 and the thin cover glass 10 is described. However, the present invention is not limited to this. It may be applied to the substrate 4 or the thin cover glass 10 side.
The silane coupling treatment may be applied to 10 in advance.

In the above-described embodiment, the optical disk according to the present invention is applied to a device that irradiates a laser beam from one side of the optical disk to reproduce information on the aluminum reflective layer.
Not limited to this, an aluminum reflective layer is formed on both sides of the substrate by the 2P method, a thin cover glass is bonded on each of the aluminum reflective layers on both sides, and laser light is irradiated from both sides of the optical disc to the aluminum The information of the reflection layer may be reproduced.

In the above-described embodiment, the present invention is applied to a method of manufacturing an optical disk such as a compact disk, but may be applied to a method of manufacturing another optical disk such as a magneto-optical disk instead.

By the way, when manufacturing a magneto-optical disc, instead of the aluminum reflective layer as the information recording layer, a perpendicular magnetization film may be formed by sputtering or the like.In this case, if an external magnetic field is applied from the objective lens side, The space between the magnetic head and the perpendicular magnetic film can be further reduced, and the configuration of the magneto-optical head can be further simplified by using a low magnetic field as the external magnetic field.

Further, in the above-described embodiment, the present invention is applied to a method of manufacturing an optical disk. However, the present invention is not limited to this, and is widely applicable to a method of manufacturing another optical information recording medium such as an optical card. is there.

H Effects of the Invention As described above, according to the present invention, a resin is filled between a signal pattern layer of a support substrate and a light transmission layer having a thickness of 50 to 200 μm, and then cured to form a light transmission layer. By adhering the layer to the support substrate, an optical information recording medium that can be recorded and / or reproduced from the light transmitting layer side can be manufactured, and thus an optical information recording medium suitable for high-density recording in a simple process. A method of manufacturing an optical information recording medium that can be manufactured can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a method for manufacturing an optical disk according to one embodiment of the present invention, and FIG. 2 is a schematic diagram showing a method for manufacturing an optical disk by a 2P method. DESCRIPTION OF SYMBOLS 1 ... Stamper, 2 ... Glass substrate, 3, 11 ... UV curable resin, 3A ... Signal pattern transfer layer, 5 ... Aluminum reflective layer, 8, 12 ... Optical disk, 10 ... Thin cover glass.

Claims (1)

(57) [Claims] A step of forming a signal pattern layer made of an ultraviolet curable resin having a fine uneven pattern transferred onto a supporting substrate; and a step of applying a laser beam having a thickness of 50 to 200 [μm] and being externally irradiated. A step of pressure-bonding a cover glass, which allows transmission on the signal pattern layer, to the signal pattern layer with a transparent adhesive layer interposed therebetween, the method comprising: