JPH11283286A - Sticking device for disk-shaped recording medium, and disk-shaped recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stacking device for a disk-shaped recording medium by which the possibility of damaging the surface on which a laser beam for recording and reproducing is made incident is prevented, and to provide a disk- shaped recording medium having no flaw on the surface by using the device. SOLUTION: In this sticking device for a disk-shaped recording medium in which an adhesive agent is interposed between two single plate disks 1a composed of polycarbonate resin plates or the like and these two single plate disks 1a are pressed and adhered between a pair of pressing plates 8 and 10 composed of stainless steel or the like, protecting sheets 8a and 10a composed of the urethane foaming bodies or polytetrafluoroethylene resins of a hardness smaller than that of the single plate disks 1a are fixed on the sbutting surfaces of the pressing plates 8 and 10 with the single plate disks 1a, and a laser beam incident side surface 1b for recording and reproducing is not damaged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc-shaped recording medium bonding apparatus and a disc-shaped recording medium, and more particularly, to a disc-shaped recording medium for pressing and bonding two single-plate discs with an adhesive therebetween. And a disc-shaped recording medium.

[0002]

2. Description of the Related Art Conventionally, a user has arbitrarily recorded information on a disk-shaped recording medium such as a ROM (Read Only Memory) disk such as a compact disk, a magneto-optical disk or a phase change disk, and reproduced the information as necessary. And RAM ((Random Access Memo
ry) There is a disk.

In recent years, a single disk having a thickness of 0.6 mm has been
DVD (Digital Vide) that has the same outer diameter (120 mm) as a compact disc
o Discs and Digital Versatile Discs) have been commercialized. ROM disk and RA in this DVD
As shown in FIGS. 7 and 8, which are schematic sectional views, there are two types of M disks. That is, as shown in FIG. 7, one type is a ROM or an R.R.
An information recording layer 2 of AM is formed, and the information recording layer 2 is bonded with an adhesive 7 with the formation surfaces thereof facing each other. In the other type, as shown in FIG. 8, although the information recording layer 2 of ROM or RAM is formed on one of the single-plate disks 1a to be bonded, the other single-plate disk 1a is bonded as a dummy. It is bonded with Agent 7.

The information recording layer 2 of a read-only ROM disk has a single-layer reflecting film of Al, Au, or the like formed on uneven recording pits of, for example, about 1/4 wavelength of the reproducing light. Is to detect a change in reflectivity due to light interference generated in the uneven recording pits. RAM
Information recording layer 2 of phase change disk as an example of disk
, For example the first dielectric layer composed of ZnS-SiO _2, for example, configured recorded film GeSbTe, for example, the second dielectric film composed of ZnS-SiO _2, reflected for example composed of Al A multilayer film such as a film is formed. Then, in this phase change disk, recording and reproduction are performed by changing a recording pattern from a crystal state to an amorphous state in accordance with recording information and detecting a change in reflectance accompanying the recording pattern. Further, on these information recording layers 2, a corrosion prevention film made of, for example, an acrylic ultraviolet curable resin is formed to prevent corrosion.

As the transparent substrate provided for the single disk 1a, polycarbonate resin, acrylic resin, epoxy resin and the like are used in addition to glass, and are particularly excellent in moldability, dimensional stability, low water absorption and the like. Therefore, polycarbonate resins are often used. A roll coating method or a spin coating method is used as a method of applying the adhesive 7 when the two single-plate disks 1a are bonded to each other. As the adhesive 7, a hot-melt adhesive, an ultraviolet curable adhesive, or the like is used. , A thermosetting adhesive or the like is used.

In recent years, as the adhesive 7 used for bonding the two single-plate disks 1a, a late-acting ultraviolet-curing adhesive which takes several minutes from the irradiation of ultraviolet rays to the complete curing is used in recent years. It is being done. By using this slow-acting ultraviolet-curing adhesive, even if the RAM disk has the information recording layer 2 formed of a multilayer film that does not transmit ultraviolet light, the two single-plate disks 1a can be bonded after the ultraviolet irradiation. It is possible to do. actually,
A corrosion prevention film made of an acrylic ultraviolet curing resin is formed on the information recording layer 2 of the single disk 1a, and a slow-acting ultraviolet curing adhesive is uniformly applied on the corrosion prevention film.
Next, the bonding surfaces of the two single-plate disks 1a face each other and are pressed and bonded. Next, the two laminated single-plate disks 1a are pressed again, and the pressed state is maintained for several minutes to further increase the bonding strength. As described above, in the step of bonding the two single-plate disks 1a,
In order to improve the throughput, a bonding process in which the bonding surfaces face each other and pressed and bonded using a bonding device for the disk-shaped recording medium 1 for several seconds to several tens of seconds, Using a bonding device, press for a few more minutes to further increase the bonding strength,
And a curing step.

The components of the pressing plate for pressing the two single-plate disks 1a in the device for bonding the disk-shaped recording medium 1 used in the bonding step and the curing step described above include:
Generally, stainless steel or structural steel having a higher hardness than the polycarbonate resin or the like forming the single-plate disk 1a is used. That is, the laser beam incident side surface 1b of the disc-shaped recording medium 1 produced by laminating the two single-plate discs 1a is directly pressed by the surfaces of these steel materials. When foreign matter is attached to at least one of the laser beam incident side surface 1b and the surface of the pressing plate of the bonding device for the disc-shaped recording medium 1,
The laser beam incident side surface 1b of the disc-shaped recording medium 1 produced by laminating the two single-plate discs 1a was scratched to affect the recording / reproducing characteristics, and there was a great risk of becoming defective. In the future, this effect will be even greater in the disk-shaped recording medium 1 which will be further increased in density, and in the bonding step and the curing step in which two single-plate disks 1a are pasted together,
There has been a demand for a device for bonding the disc-shaped recording medium 1 which does not have a possibility of damaging the laser beam incident side surface 1b.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus for bonding a disk-shaped recording medium which does not have a possibility of damaging the surface on which a recording / reproducing laser beam is incident and which can be further densified. And to provide a high-quality disc-shaped recording medium having no damage on the surface on the side where the recording / reproducing laser beam is incident by using this.

[0009]

In order to solve the above-mentioned problems, in the apparatus for bonding a disk-shaped recording medium according to the present invention, an adhesive is interposed between two single-plate disks, and the two single-plate disks are interposed. In a disc-shaped recording medium bonding apparatus in which a plate disk is sandwiched between a pair of pressing plates and pressed and bonded, a protection sheet having a hardness smaller than that of the single disk is fixed to a contact surface of the pressing plate with the single disk. Then, the surface of the single disk on which the recording / reproducing laser beam is incident is not damaged. And, as a material constituting the protective sheet,
Any material can be used as long as it is a material having a hardness smaller than that of the single-plate disk, but a urethane resin foam or a polytetrafluoroethylene resin is particularly desirable.

[0010] A disk-shaped recording medium of the present invention is characterized by being produced by using the disk-shaped recording medium bonding apparatus of the present invention.

According to the above-described means, there is no possibility that the recording / reproducing laser light incident on the surface on the incident side of the recording / reproducing laser beam which affects the recording / reproducing characteristics of the disk-shaped recording medium is damaged. It is possible to provide a simple disk-shaped recording medium.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a ROM or a RAM on at least one of at least two single-plate disks.
An information recording layer is formed, and an adhesive is interposed between the two single-plate disks, and the two single-disk plates are sandwiched between a pair of pressing plates and bonded by pressing. The present invention can be applied to a disc-shaped recording medium manufactured by using a laminating apparatus and a disc-shaped recording medium bonding apparatus.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a disk-shaped recording medium manufactured by using the disk-shaped optical recording medium bonding apparatus of the present invention will be described with reference to FIGS. Note that components in the figure that have the same structure as the conventional technology are denoted by the same reference numerals.

Embodiment 1 In this embodiment, a recording is made of a first dielectric film composed of four layers of ZnS-SiO ₂ and GeSbTe on each of two single-plate disks 1a to be bonded. Film, ZnS-
A _second dielectric film composed of SiO ₂ and an information recording layer 2 composed of a reflective film composed of Al are formed;
This is an example in which a slow-acting ultraviolet curable adhesive (trade name: SK-7000, manufactured by Sony Chemical Co., Ltd.) is used as the adhesive 7 for bonding the two single-plate disks 1a. In addition,
As the single-plate disk 1a, a polycarbonate resin obtained by injection molding with a disk diameter of 120 mm and a plate thickness of 0.6 mm was used.

First, as shown in FIG. 1, an acrylic UV curable resin, for example, is dropped as an anti-corrosion film liquid 3 on the information recording layer 2 of the single disk 1a, and the average film is formed by spin coating. An acrylic ultraviolet curable resin film having a thickness of 15 μm is formed. In this case, an acrylic ultraviolet curable resin film having an average film thickness of 15 μm is formed on each of the two single-plate disks 1a.

Next, as shown in FIG. 2, an ultraviolet lamp 4 is used to irradiate the acrylic ultraviolet-curable resin film of the single-plate disk 1a with ultraviolet light of 300 mJ / cm ² using an ultraviolet lamp. The corrosion prevention film 3a in which the resin film is cured is formed. In this case, two single-plate discs 1
Irradiation of ultraviolet light with an amount of ultraviolet light of 300 mJ / cm ² is applied to each of the a to form the corrosion prevention film 3a.

Next, as shown in FIG. 3, the screen 6 is covered so as to cover the corrosion prevention film 3a of the single-plate disk 1a, and a slow-acting ultraviolet-curing adhesive Is dropped. Then, using the squeegee 5, a slow-acting ultraviolet curable adhesive is applied on the corrosion prevention film 3a.
The adhesive is uniformly applied so that the thickness of the adhesive is 30 μm. In this case, any one of the corrosion prevention films 3a of the two single-plate disks 1a
A slow-acting UV-curable adhesive is evenly applied thereon so that the thickness of the cured adhesive is 30 μm.

Next, as shown in FIG. 4, ultraviolet rays having an amount of ultraviolet rays of 300 mJ / cm ² are applied to the surface of the single-disk 1a on which the slow-acting ultraviolet-curable adhesive is applied, using an ultraviolet lamp 4. In this case, both of the two single-plate discs 1a have a UV light amount of 30
Irradiate with ultraviolet rays of 0 mJ / cm ² . The two single-plate disks 1a that have been irradiated with the ultraviolet rays are bonded together using the disk-shaped recording medium 1 bonding apparatus shown in FIG.

The schematic configuration of the apparatus for bonding the disk-shaped recording medium 1 used here will be described with reference to FIG. At the center of one of the pressing plates 8 made of stainless steel or the like, a columnar central shaft 9 whose outer diameter is slightly smaller than the center hole diameter of the single-plate disk 1a is positioned with respect to the main surface of the pressing plate 8. It is vertically suspended and fixed. A urethane resin foam having a hardness of 0.5 mm and a hardness smaller than that of the component of the veneer disk 1a is provided on the surface of the pressing plate 8 on which the central axis 9 is vertically provided and which comes into contact with the veneer disk 1a. A protection sheet 8a made of a body is fixed. On the other hand, the other end of the pressing plate 10 made of stainless steel or the like is provided with an opening having a diameter slightly larger than the outer diameter of the center shaft 9 and inserted through the center shaft 9. Similarly to the pressing plate 8, a protective sheet 10 a made of urethane resin foam having a thickness of 0.5 mm is also fixed to the contact surface of the pressing plate 10 with the single-plate disk 1 a. When a convex portion such as a stack rib is formed on the disk-shaped recording medium 1, concave portions corresponding to the position where the convex portion is formed and its shape are provided on the pressing plates 8 and 10.

Hereinafter, the continuation of the step of bonding the two single-plate disks 1a using the disk-shaped recording medium 1 bonding apparatus will be described with reference to FIG. 5 again.

Next, the two single-plate disks 1a are placed in such a manner that their respective surfaces coated with a slow-acting UV-curable adhesive face each other.
It is inserted through the central shaft 9 in order. Here, the pressing plates 8, 1 of the present invention
0 on the contact surface with the single disk 1a.
In order to confirm the effect of fixing the single disk 1a, a small 0.3 mm square piece of polycarbonate resin made of the same material as the single disk 1a was used as the foreign substance 11 to be inserted between the pressing plates 8, 10 and the single disk 1a. On an arbitrary information recording layer formed on the substrate. The reason why the polycarbonate resin small piece was selected as the foreign material 11 is that burrs generated at the time of molding the single disk 1a often become the foreign material 11.

Next, the pressing plate 10 is pressed so that the surface of the pressing plate 10 on which the protective sheet 10a is formed is in contact with the single disk 1a.
Through the center shaft 9.

Next, a pressure of 9.8 × 10 ³ Pa is applied uniformly from the surface of the pressing plate 10 opposite to the surface on which the protective sheet 10a is formed.
Then, the two single disks 1a are pressed and bonded.
After this bonding step, the area of the concave portion formed by the foreign matter 11 is determined by using an optical disk appearance inspection device (trade name: VCD-12).
0CTNL, Dr. Schenk).

Next, as shown in FIG. 6, the bonding strength of the disk-shaped recording medium 1 is further increased by using the same device as the example described with reference to FIG. At this time, a newly prepared 0.3 is prepared on the information recording layer 2 at a position different from the position where the foreign material 11 which is a small 0.3 mm square polycarbonate resin piece was placed in the previous bonding step.
A small piece of polycarbonate resin of square mm was placed. And
The pressing plate 10 was uniformly pressed from the surface opposite to the surface on which the protective sheet 10a was formed at a pressure of 1.3 × 10 ³ Pa for 15 minutes to further increase the adhesive strength of the two single-plate disks 1a. Thereafter, the pressure was released to complete the disk-shaped recording medium 1 on which the two single-plate disks 1a were bonded. After this curing step, the area of the concave portion formed by the foreign matter 11 is again determined by using an optical disk appearance inspection device (trade name: VCD-120CT).
NL, Dr. Schenk).

Embodiment 2 In this embodiment, 0.5 mm thick polytetrafluoroethylene is used as a constituent material of the protective sheets 8a and 10a which are fixed to the contact surfaces of the pressing plates 8 and 10 with the single plate disk 1a. Except that resin was used, a disk-shaped recording medium 1 on which two single-plate disks 1a were stuck was completed through the same steps as in Example 1 (the same as in Example 1, foreign matter 11 was put and pressed and bonded). did). Then, in the same manner as in Example 1, after the bonding step and the curing step, the area of the concave portion formed by the foreign matter 11 is measured using an optical disk appearance inspection device ((trade name: VCD-1)
20 CTNL, Dr. Schenk).

Comparative Example In this comparative example, two pressing plates 8 and 10 made of conventional stainless steel to which the protective sheets 8a and 10a were not fixed were subjected to the same process as in Example 1 and two single plates were used. The disk-shaped recording medium 1 to which the plate disk 1a was bonded was completed (the foreign matter 11 was put in and pressed and bonded as in Example 1). Then, as in Example 1, after the bonding step and the curing step, the area of the concave portion formed by the foreign matter 11 is determined by using an optical disk appearance inspection device (trade name: VCD-120CTN).
L, Dr. Schenk).

Table 1 shows the measurement results of the area of the concave portion after the bonding step and the curing step in Examples 1 and 2 and the comparative example.

[0028]

[Table 1]

As is clear from Table 1, the area of the concave portion after the bonding step is compared with Examples 1 and 2 and the comparative example. In Example 1, the area is about 1/18 of the comparative example. In Example 2, it was approximately 1/11. Further, when comparing Examples 1 and 2 and Comparative Example with respect to the area of the concave portion after the curing step, Example 1 shows that
39, which was approximately 1/21 in Example 2. From this, if the present invention is applied and the bonding device of the disk-shaped recording medium 1 in which the protection sheets 8a and 10a are fixed to the surfaces of the pressing plates 8 and 10 that abut on the single-plate disks 1a is used, two sheets are required. Laser beam incident side surface 1b of single disk 1a
Alternatively, one of the protection sheets 8a and 10a
Even if 1 adhered, it was confirmed that the scratching area could be greatly reduced.

[0030]

According to the disk-like recording medium bonding apparatus of the present invention, it is possible to provide a disk-like recording medium bonding apparatus which does not have a possibility of damaging the surface on which the recording / reproducing laser beam is incident. By using this, it is possible to provide a high-quality disk-shaped recording medium that can cope with higher densities and has good recording and reproduction characteristics.

[Brief description of the drawings]

FIG. 1 is a process explanatory view illustrating a process for producing a disk-shaped recording medium of the present invention.

FIG. 2 is a process explanatory view following FIG. 1 for explaining a manufacturing process of the disk-shaped recording medium of the present invention.

FIG. 3 is an explanatory process diagram illustrating a manufacturing process of the disk-shaped recording medium of the present invention, following FIG. 2;

FIG. 4 is a process explanatory view following FIG. 3 for explaining a manufacturing process of the disk-shaped recording medium of the present invention.

FIG. 5 is a schematic configuration diagram of the disk-shaped recording medium bonding apparatus of the present invention, and is a process explanatory view following FIG. 4 for explaining a manufacturing process of the disk-shaped recording medium of the present invention.

FIG. 6 is a schematic configuration diagram of the disk-shaped recording medium bonding apparatus of the present invention, and is a process explanatory view following FIG. 5 for explaining a manufacturing process of the disk-shaped recording medium of the present invention.

FIG. 7 is a schematic cross-sectional view of a conventional disk-shaped recording medium, in which an information recording layer is formed on two single-plate disks to be bonded.

FIG. 8 is a schematic cross-sectional view of a conventional disk-shaped recording medium, in which one of two single-plate disks to be bonded is a dummy.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disc-shaped recording medium, 1a ... Single disk, 1b ...
Laser light incident side surface, 2 ... Information recording layer, 3 ... Corrosion prevention film solution, 3a ... Corrosion prevention film, 4 ... Ultraviolet lamp, 5 ... Squeegee, 6 ... Screen, 7 ... Adhesive, 8 ... Pressing plate, 8a ...
Protective sheet, 9 central axis, 10 pressing plate, 10a protective sheet, 11 foreign matter

Claims (3)

[Claims] 1. A disc-shaped recording medium bonding apparatus in which an adhesive is interposed between two single-plate disks and the two single-plate disks are sandwiched between a pair of pressing plates and pressed and bonded. An apparatus for bonding a disk-shaped recording medium, wherein a protection sheet having a lower hardness than the single-plate disk is fixed to a contact surface of the pressing plate with the single-plate disk. 2. The apparatus according to claim 1, wherein the protective sheet is made of one of a urethane resin foam and a polytetrafluoroethylene resin. . 3. A disk-shaped recording medium manufactured by using the disk-shaped recording medium bonding apparatus according to claim 1.