JPS60121557A - Manufacture of optical information carrier disk - Google Patents

Abstract

PURPOSE:To allow transfer of a signal track, etc. from a stamper by providing an annular recessed stage part at the outside of an effective signal track forming area and protruding a thermo setting resin to the outer circumference of a disk substrate. CONSTITUTION:A disk substrate 10 forms an annular recessed stage part 11 with the prescribed depth at the outside of an effective signal track forming area. The annular recessed stage part 11 provided on the disk substrate 10 is filled with a UV resin 4; therefore the UV resin 4 will not protrude from the disk sub strate 10. In order to fill the width 12 of the recessed stage part 11 with the UV resin 4, the width of the recessed stage part 11 and the applying amount of the UV resin 4 are controlled. When it is assumed that the depth 13 of the recessed stage part 11 will be more than four times the thickness of UV resin layer, flowing out of the UV resin layer due to a capillary phenomenon can be prevented. If the surface of the concave stage part 11 is finished so that its surface coarseness will be more than Ra3mum, adhesiveness of the UV resin 4 and the disk substrate 10 can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing an optical information carrier disk (hereinafter simply referred to as an optical disk) for optically recording, reproducing, or reproducing video information, etc.

Conventional configuration and its problems Optical recording and reproducing systems record and reproduce information by irradiating the recording film of an optical disc with a laser beam that corresponds to the information signal, creating optical shading or unevenness on the thin recording film. This method is capable of recording minute signals of several micrometers, and in principle enables high-density recording on the order of the wavelength of light.

This optical recording/playback method eliminates wear because the laser light pickup and optical disk do not come into contact during recording and playback, providing multi-functionality such as still images and high-speed search, and is practical for industrial and business purposes such as still image files and document files. It is becoming more and more popular.

In addition, playback-only optical discs such as optical video discs and digital audio discs have also been put into practical use.

One of the methods of forming a signal l/rack for laser light guide or a concavo-convex phase type signal bit on the disk substrate of these optical disks is to use a curable resin (for example, ultraviolet curable resin, hereinafter simply referred to as UV resin). Another method is to transfer the signal track grooves formed on a stamper onto a disk substrate.

A conventional method of transferring signal track grooves and the like using UV resin will be described below. FIG. 1 is a cross-sectional front view showing a corrective method for transferring signal tracks, etc. using conventional UV resin.
is the stamper that formed the signal track 2. 3 is a resin substrate that becomes a disk substrate; 4 is a UV resin filled between the signal track 2 of the stamper 1 and the disk substrate 30; 6
is a transparent pressurized glass plate that transmits ultraviolet light. Reference numeral 6 denotes an ultraviolet lamp which irradiates ultraviolet rays in the direction of arrow 8 using a reflector plate 7. A method of transferring the signal track 2 configured as described above will be explained. U on the signal track 2 side of stamper 1
The V-resin 4 is applied, the disc substrate 3 is placed on top of the V-resin 4 to prevent air bubbles from being mixed therein, and the entire surface of the disc substrate 3 is filled with the UV resin 4 by pressing with a pressure glass plate 5. Next, when ultraviolet rays are irradiated as shown by arrow 8, the ultraviolet rays pass through pressurized glass plate 5 and disk substrate 3 and cure UV resin 4. After the UV resin 4 is cured in this way, the pressurized glass plate 5 is removed as shown in FIG. The signal track 2 of the stand 1 can be transferred onto the stand 3. In addition, the pitch of this signal trunk, or the signal bit of the uneven phase difference, is usually highly accurate at 1 to 3 μm, so even a small amount of foreign matter or defects may cause errors such as dropouts, so it should be kept in a clean room. The above-mentioned manufacturing is carried out within the factory. In this method, even if the working environment is completely clean, minute foreign matter is generated during the manufacturing process, causing errors such as dropouts. That is, as shown in FIG. 3, the UV resin 4 overflowing to the outer periphery of the disk substrate 3 gradually becomes thinner, and its outermost periphery 9 becomes extremely thin. When the UV resin 4 is cured in this state, the outermost peripheral portion 9 is also naturally cured. When the UV resin 4 cured in this way is peeled off from the stamper 1, the extremely thin UV resin at the outermost circumferential portion 9 is not peeled off integrally with the UV resin 4 filled in the area of the disk substrate 3, and a minute amount of the UV resin 4 is peeled off from the stamper 1. The resin layer adhered to the UV41 resin surface onto which signal tracks and the like were transferred due to static electricity generated during peeling, causing errors such as dropouts. In addition, when a disk substrate manufactured in this way is transported by hand, the outer edge of the disk substrate is usually held, but since this outer edge is very thin, new resin is used during transfer. Powder is generated. Furthermore, since the stand used for storage etc. is held at the outer peripheral end, it also hinders the cleanliness of the entire manufacturing process.

As a countermeasure to this problem, it is possible to prevent the UV resin from overflowing only to the circumference of the disk substrate.

By eliminating overflow of the UV resin to the outer periphery, it becomes possible to reduce dropouts due to collapse of the UV resin, and at the same time, it becomes easier to transport and store the disk substrate.

FIG. 4 shows an example in which the UV resin does not overflow onto the outer periphery of the disk substrate. As shown in FIG.
It is possible to reduce dropouts caused by the collapse of the resin 4. However, it was not possible to obtain a uniform UV resin layer over the entire surface. Specifically, the UV resin flowed out toward the outer circumference (in the direction of the arrow shown in Figure 4) due to capillary phenomenon, causing the thickness of the UV resin layer near the outer circumference to increase. has become thinner.

Purpose of the Invention The present invention solves the above-mentioned conventional problems, and provides high-quality signal tracks without generating minute foreign matter such as resin powder when transferring signal tracks, etc. from a stamper to a disk substrate using a curable resin. It is an object of the present invention to provide a manufacturing method that can obtain the following properties and also make the manufacturing process cleaner.

Structure of the Invention The present invention provides an annular concave step outside the effective signal track forming area on the signal track transfer surface side of a disk substrate, and fills the concave step area with a curable resin, thereby reducing the thickness of the curable resin layer. This is a manufacturing method that allows transfer of signal tracks, etc., without the curable resin overflowing to the outer periphery of the disk substrate.

In other words, the end of the curable resin layer is located in a part (concave step) that is larger than the thickness of the curable resin layer to prevent the curable resin from flowing out due to capillarity, and to obtain the thickness of the curable resin layer while at the same time By filling the concave step area without letting the resin protrude from the disk substrate, the curable resin end has a sufficient thickness and has an end face shape with curvature due to surface tension.
This reduces the generation of resin powder that occurs when the curable resin is peeled off, and also prevents the generation of new resin powder during transportation and storage.

DESCRIPTION OF THE EMBODIMENTS FIG. 6 is a sectional view showing a method of transferring signal tracks according to an embodiment of the present invention. In Figure 5, Figures 1 to 4
Components that are the same as those in the figures will be explained using the same numbers. In FIG. 6, reference numeral 1 denotes a stamper on which a signal track 2 is formed. 1
o is a disk substrate according to the present invention, and is a disk substrate in which an annular recessed step 11 of a predetermined depth d is formed outside the effective signal track forming area. 4 is a UV resin (ultraviolet curing resin) layer. UV resin layer 4//i Pressurized by pressurized glass plate 6, annular recessed step 11 provided on disk substrate 1o
Filled within the area. Thereafter, the configuration and operation of the ultraviolet lamp 6 and the reflection plate 7 are the same as those described in the conventional example.

The signal track transfer method of this embodiment configured as described above will be explained below.

As shown in FIG. 6, by filling the UV resin 4 into the annular recessed step 11 area provided on the disk substrate 1o,
The V-resin 4 is not allowed to protrude beyond the disk substrate 10. In order to fill the width 12 of the recessed step 11 with the UV resin 4, the width 12 of the recessed step 11 and the amount of UV resin 4 applied are controlled. The UV resin 4 filled in the four step portions 11 is large in quantity, and even if there is a slight difference in the amount applied, it is easy to position the end of the UV resin 4 within the width 12 of the recessed step portion 11. becomes. Next, if the depth 13 of the recessed step portion 11 is set to be four times or more the thickness 14 of the UV resin layer, it is possible to prevent the UV resin layer from flowing out due to capillary action.

Further, the UV resin terminal portion has a curvature shape due to surface tension, so that the UV resin is less likely to collapse. Furthermore, by finishing the surface roughness Ra of the recessed step portion 11 to be 3 μm or more, it is possible to improve the adhesion force between the UV resin 4 and the disk substrate 1o, and this can also be used as a measure for improving the adhesion direction.

A recording film 15 is formed on the replica plate thus created, and a protective substrate 16 provided with a concave step 11 similar to that of the disk substrate 1o is bonded thereto. It is shown in FIG. 17 is a UV resin.

Next, finish the outer diameter of the disk as shown by the two-dot thin line.

Although one embodiment of the present invention has been described above, similar effects can be obtained by using a disk substrate provided with an annular recessed step as shown in FIG.

Further, although the embodiment of the present invention shows only the outer periphery of the disk substrate, the same effect can be obtained also on the inner periphery (near the center hole).

Furthermore, although the present invention has been explained using a disk substrate made of resin, the same applies to a disk substrate made of a glass substrate.

Effects of the Invention As described above, according to the present invention, signal track grooves, etc. can be transferred from the standber with a structure in which the curable resin does not protrude to the outer or inner periphery of the disk substrate. It is possible to reduce outflow and at the same time obtain a uniform resin layer thickness. Since the curable resin does not collapse during transportation or storage, it is possible to reduce dropouts and keep the clean room clean. Furthermore, by controlling the surface roughness of the annular recessed portion provided on the signal track transfer surface side of the disk substrate, it was possible to improve the adhesive strength between the curable resin and the disk substrate.

[Brief explanation of drawings]

Figure 1 is a side sectional view of an apparatus showing an overview of a conventional optical information disc manufacturing method, Figure 2 is a side sectional view showing the peeling state of the manufacturing process in the same apparatus, and Figure 3 is the outer periphery of the same disk substrate. FIG. 4 is a lateral cross-sectional view of an optical information carrier disk showing prevention of UV resin extrusion in a conventional example, and FIG. 6 is a method for manufacturing an optical information carrier disk according to the present invention. 6 is a side sectional view of the main part of the disk substrate according to the present invention, and FIG. 7 is a side sectional view showing the post-process of the method for manufacturing an optical information carrier disk according to the present invention. FIGS. 8a and 8b are side sectional views of a disk manufactured by a method for manufacturing an optical information carrier disk in another embodiment of the present invention, respectively. DESCRIPTION OF SYMBOLS 1... Stamper, 10... Disk substrate, 11... Annular concave step, 4... UV resin layer, 5... Glass plate . Name of agent: Patent attorney Toshio Nakao and 1 other group
1 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7! 6 (a)

Claims (3)

[Claims] (1) forming an annular recessed step on the side of the transfer surface outside the effective signal track formation area of the disk substrate onto which the signal track is to be transferred, via a hardening resin from the stump where the signal track is formed; An optical information carrier characterized in that the curable resin is filled from the signal track area into the recessed step area, and after the curable resin is cured, the curable resin is peeled off together with the disk substrate using a stand gullet. Disc manufacturing method. (2) The concave step provided on the disk substrate is made of curable resin 1-
2. The method of manufacturing an optical information carrier disk according to claim 1, wherein the depth is four times or more the thickness. (3) Raise the surface roughness of the concave step provided on the disk substrate.
Claim 1 characterized in that the diameter is 3 μm or more.
A method for producing an optical information carrier disk as described in Section 1.