JPH11238261A - Manufacturing method of optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the handling of a pressure sensitive adhesive sheet, which is a protective substrate, and to reduce the number of turn over defects by recording signals employing fine pits or grooves, forming a reflective film or a recording layer over them to form a plate and pasting a flexible and protective substrate, which beforehand has an adhesive layer, with the plate. SOLUTION: A disk plate 1 is vacuum sucked to a disk plate suction table 3 while the projected section of a clamping area section is faced up. The portion, which corresponds to the clamping area, is cut out from a resin sheet 21 to make a flexible and protective substrate material 2'. The part, which corresponds to the pasting surface of the material 2', is coated with an adhesive layer 22. Then, the material 2' is positioned against the plate 1 while the adhesive surface is faced down, pressed by a rubber elastic pad 42 from the top, pasted and cut. Since the adhesive is beforehand formed on a protective substrate 2', it is hard to make wrinkles on the substrate 2. Moreover, no air bubble exists on the pasted surface because the substrate 2 is flexible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a bonded optical disk.

[0002]

2. Description of the Related Art Optical disks are used in a wide variety of fields such as image information, music information, and data storage media for computers. The optical disks are classified into a read-only optical disk, a write-once optical disk, a rewritable optical disk, and the like, and are used appropriately.

[0003] In these optical disks, a reflective film or a recording film is formed on a substrate on which a signal is formed by fine pits or grooves, and after applying an adhesive to the reflective film recording film, a protective substrate is bonded or reflected. It is manufactured by applying and curing a photocurable resin on the film or the recording film.

[0004]

In the manufacture of an optical disk in which the entire information recording surface of the disk substrate is bonded to the protective substrate, a UV-curable (cationic or radical) adhesive or a hot-melt adhesive is used as an adhesive material. Etc. are used. Adhesive sheets are also used in the production of laser disks (LD) and the like. Among them, the method using the pressure-sensitive adhesive sheet has an advantage that the laminating step can be performed at room temperature and the temperature control is easy. On the other hand, if the adhesive sheet is not a structure in which the base film is sandwiched by an adhesive like a normal double-sided tape, but is bonded using a sheet of adhesive only, the adhesive sheet is treated However, it is difficult to stably bond the disk substrate and the protection substrate with wrinkles, curls and the like.
In addition, UV light is applied to the bonding surface of the disc substrate with information.
If there is unevenness in the thickness of the protective layer due to the cured resin or the like, or if the disk substrate itself has irregularities, air bubbles are likely to remain in the concave portions when bonding with the protective substrate, and a defoaming step is provided to remove the air bubbles. This hindered cost reduction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing an optical disk at a low cost by reducing the defects such as the curling of the sheet by facilitating the handling of the adhesive sheet.

[0006]

According to the present invention, first, a disk substrate 1 on which a signal is provided by fine pits or grooves and a reflective film or a recording film is formed thereon, In a method for manufacturing an optical disk, wherein the protective substrate 2 provided with an adhesive layer in advance is bonded to the disk substrate 1 in a method for manufacturing an optical disk comprising: You.

Secondly, there is provided a method for manufacturing an optical disk, characterized in that a material having flexibility is used as the protective substrate 2 in the first method for manufacturing an optical disk.

Third, in the above-mentioned first or second optical disk manufacturing method, the clamping area of the disk base 1 forms a projection having a height substantially equal to the thickness of the protection substrate 2 from the information recording surface. In addition, there is provided a method of manufacturing an optical disk, wherein a portion corresponding to a clamping area of a protective substrate 2 provided with an adhesive layer in advance is cut.

Fourth, in the first, second, or third optical disk manufacturing method, the protective substrate 2 is supplied as a continuous sheet, which is adhered to the disk substrate 1, and the outer diameter of the disk substrate 1 is reduced. And a method for manufacturing an optical disc, characterized in that the optical disc is cut out in accordance with the method.

According to the optical disk manufacturing method of the present invention,
Since the pressure-sensitive adhesive layer is provided on the protective substrate 2 in advance, the protective substrate 2 does not wrinkle or turn up when bonded to the disk substrate 1, so that stable optical disk production can be performed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1A shows a state immediately before the protection substrate 2 is bonded to the disk substrate 1. In FIG. 1A, a signal obtained by applying fine pits or grooves on a substrate and a reflective film or a recording film is formed on the substrate (disk substrate 1) is formed on a disk substrate suction table 3 by a reflective film or a recording film. It is placed on top. In addition, a protective substrate material 2 ′ provided with an adhesive layer is disposed between the disk substrate 1 and the press 4 in a sheet shape. FIG. 1 (b)
Indicates a state in which the press 4 is lowered and the protective substrate material 2 ′ is bonded to the disk substrate 1. FIG. 1C shows the optical disk taken out of the disk substrate suction table 3 by raising the press 4.

The press 4 has a mortar shape in cross section, has a positioning portion 41 at the center, and a pad 42 having rubber elasticity.
When the protective substrate material 2 'is contracted by pressing it against the disk substrate 1, the positioning portion 41 is also contracted by a spring, for example. Further, a blade 43 is provided at a required tip portion on the outer periphery of the press 4. By the way, as shown in FIG. 2, the protective substrate material 2 ′ used in the apparatus shown in FIGS. 1A and 1B is preferably provided with a plurality of cuts 211 and a clamp portion cut hole 212 in the resin sheet 21. It is a long one having the layer 22 formed thereon. Polyethylene, vinyl resin, vinyl chloride resin, or the like is used for the resin sheet 21, and an acrylic adhesive or the like is used for the adhesive. According to the sheet-like protective substrate material 2 ′, the protective substrate 2 can be easily attached to the disk substrate 1.

FIG. 3 schematically shows an apparatus useful for continuously performing the method of the present invention. The protective substrate material 2 ′ is unwound from the roll, and after the protective substrate 2 is attached to the disk substrate 1, it is wound again. The protective substrate material 2 'to be rolled may be (1) a pressure-sensitive adhesive applied to the unwound resin sheet, or (2) a pressure-sensitive adhesive applied to the resin sheet from the beginning. To the release paper, and the release paper may be peeled off while unwinding.

[0014]

Next, the present invention will be specifically described based on examples.

Embodiment 1 In FIG. 1, only the clamping area has a thickness of 1.2.
The disk substrate 1 having a diameter of 1 mm is vacuum-adsorbed to the disk substrate adsorption table 3 with the convex portion facing upward. The protective substrate material 2 'is supplied in a state where a portion corresponding to a clamping area is cut from a resin sheet 21 having a thickness of 0.6 mm, and a portion corresponding to a bonding surface is coated with an adhesive layer 22. This protective substrate material 2 'is placed on the disk substrate 1 with the adhesive side down.
And stick them together. The bonding is performed by pressing the protective substrate material 2 ′ from above with a pad 42 having rubber elasticity. When the bonding is completed, the supporting portion on the outer peripheral portion of the resin sheet 21 is cut off to obtain a bonded optical disk.

Example 2 In FIG. 2, a resin sheet 21 having a thickness of 0.6 mm
A portion corresponding to the clamp area is cut, and a portion corresponding to the outer diameter of the disk is also provided at several support portions (in FIG. 2A, four sheet support portions are provided at the top, bottom, left, and right).
Are cut, and a large number of portions on which the pressure-sensitive adhesive layer 22 is formed are formed side by side on a portion corresponding to the bonding surface. This sheet-like protective substrate material 2 'was rolled and applied to the apparatus shown in FIG. 3 to produce an optical disk.

[0017]

(1) According to the first aspect of the present invention, since the pressure-sensitive adhesive layer is formed on the protective substrate 2 in advance, wrinkles are formed on the protective substrate 2 when the disk substrate 1 and the protective substrate 2 are bonded to each other. There is no danger of turning over or turning over, and stable production is possible. (2) According to the second aspect of the present invention, since the protective substrate 2 can be flexed freely at the time of bonding, there is no possibility that air bubbles enter the bonding surface. Further, since the protective substrate 2 follows the minute unevenness of the bonding surface of the disk substrate 1, no air bubbles remain in the concave portion. (3) According to the third aspect of the invention, the thickness of the clamping portion for supporting the disk substrate 1 is increased, so that the disk substrate 1
Is improved. (4) According to the invention of claim 4, since the protection substrate 2 can be manufactured by cutting out a resin sheet, the cost is reduced. Further, since a robot hand is not required as in the case of supplying the protection substrate 2 in a single wafer, an optical disc can be manufactured at a low cost with a compact bonding apparatus.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are views for explaining an optical disk manufacturing method of the present invention, and FIG. 1 (c) is a view showing a layer configuration of an obtained optical disk.

FIG. 2A is a plan view of a sheet-like protective substrate material,
FIG. 2B is a cross-sectional view of the sheet-like protective substrate material.

FIG. 3 is a diagram showing an apparatus for manufacturing an optical disk using a long protective substrate material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disc board 2 Protective board (2 'protection board material) 3 Disc board suction table 4 Press 21 Resin sheet 22 Adhesive layer 41 Positioning part 42 Pad 43 Blade 211 Notch 212 Clamp cut hole

Claims (4)

[Claims] 1. A protection substrate 2 comprising: a disk substrate 1 on which a signal is formed by fine pits or grooves, on which a reflection film or a recording film is formed; A method for manufacturing an optical disk, comprising: bonding a protective substrate (2) provided with an adhesive layer in advance to the disk substrate (1). 2. The method according to claim 1, wherein a material having flexibility is used as the protective substrate. 3. The clamping area of the disk base 1 forms a projection having a height substantially equal to the thickness of the protection substrate 2 from the information recording surface, and the protection substrate 2 provided with an adhesive layer in advance is clamped. 3. The method according to claim 1, wherein a portion corresponding to the area is cut. 4. The protection substrate 2 is supplied as a continuous sheet,
After attaching this to the disk substrate 1, the disk substrate 1
2. The cut-out according to the outer diameter of
4. The method for manufacturing an optical disc according to 2 or 3.