JPS6371956A - Production of optical recording medium - Google Patents

Abstract

PURPOSE:To easily obtain an optical recording medium which is free from positional deviations by executing a stage for superposing two sheets of substrates in such a manner that the recording layers thereof are positioned on the inside by a sticking jig for positioning the disk substrates by the outer periphery thereof and curing an adhesive agent continuously after a stage for coating the adhesive agent to the substrates. CONSTITUTION:This production process consists in the continuous execution of the stage for coating the adhesive agent 1 to one of two sheets of the disk substrates, at least one of which is formed with the recording layer for executing information recording by laser light, then the stage for superposing two sheets of the substrates in such a manner that the recording layers are positioned on the inside by the sticking jig 3 for positioning the substrates 2 by the outer periphery thereof and curing the adhesive agent 1. Easy packaging of the sticking type disk without positional deviations is thereby permitted. The bleeding of the adhesive agent to the inner and outer peripheral ends by mis-alignments and the creeping of the adhesive agent to the recording area near the outer periphery of the hollow structure are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing an optical recording medium that can perform recording and reproduction using a light beam.

[Conventional technology]

Rare earth-transition metal alloy thin film on a transparent substrate,
An optical memory material such as a thin film of a reducing oxide such as a chalcogen compound that utilizes phase transition from amorphous to crystalline, or a thin film of a heat mode recording medium is formed, and two recording media or one recording medium and Optical recording media have been proposed that have a bonded structure in which a substrate without a recording layer is bonded to the substrate so that the recording layer is on the inside, or an air sandwich structure in which a spacer is sandwiched between the recording media and bonded together.

If this optical recording medium is in particular an optical disc,
Grooves having a pitch width of usually about 1 to 2 microns are spirally provided on the substrate as guide grooves for laser beam scanning for recording and reproduction. This spiral groove and the center hole of the disk require extremely high eccentricity accuracy. However, after applying adhesive to the substrates and pasting them together, the two substrates tend to shift until the adhesive hardens, causing the adhesive to protrude onto the edge of the center hole, reducing the accuracy of the center hole. .

In addition, in the case of a recording medium with an air sandwich structure, for example, in a recording medium with an outer diameter of 130 mm, the seal width at the outer periphery where the adhesive is applied is about 3 m11, and if the two substrates are misaligned, the recording area near the outer periphery will be corroded. There is a drawback. Furthermore, if the two substrates are bonded together with even a slight deviation, there is a drawback that one rotation unevenness occurs when recording and reproducing are performed at a higher rotation speed in order to increase the data transfer speed.

[Problem that the invention seeks to solve]

The purpose of the present invention is to eliminate the above-mentioned drawbacks, and the purpose of the present invention is to use a bonding jig that aligns the disk substrate by the outer periphery after the process of applying adhesive, so that the recording layer is placed on the inside. It is an object of the present invention to provide a manufacturing method that can easily obtain an optical recording medium without positional deviation by sequentially performing the steps of overlapping two substrates and curing an adhesive.

[Means for solving problems]

The present invention provides two disk substrates, at least one of which has a recording layer for recording information using a laser beam.
A step of applying adhesive to at least one disk substrate, and then a step of curing the adhesive by stacking the two substrates so that the recording layer is on the inside using a bonding jig that aligns them by the outer periphery of the disk substrate. This method of manufacturing an optical recording medium is characterized in that the following steps are continuously performed.

The optical recording medium manufactured according to the present invention has a substrate made of glass, a synthetic resin such as polymethyl methacrylate, polycarbonate, etc., a metal such as Te or Bi, a cyanine-based material,
Hole formation represented by organic dyes such as methine, As-Te
- Phase change represented by Ge system, TeOx system, etc., GdCo
, TbFe, TbFeCo, GdTbFeC: o, and other materials that utilize magnetization reversal, etc., can be recorded by light,
A reproducible material is provided as a recording layer. In addition to the materials mentioned above, the substrate and the recording layer may be made of any other material suitable for optical recording and reproduction.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

Fig. ff51 shows a process schematic diagram of an example according to the method of the present invention. Examples of the adhesive application process include a) roll coating and b) dispenser application. C), d
) and e) are examples of the bonding process.

The method of applying adhesive to the disk substrate on which the recording layer is formed is as shown in FIG. If it is a laminated structure in which the recording layer is glued on the inside, the adhesive 1 is supplied between the fantine roller and the transfer roller and the amount of application is adjusted as shown in Fig. 1a). Roll coating is suitable, in which the adhesive layer 5 is formed by transferring the substrate 2 to a roller and passing the substrate 2 between a composition roller and an impression roller positioned below the composition roller and serving as a suppressor. In addition, as shown in Figure 2 b) and c), if the recording medium has a hollow structure in which spacers are sandwiched and bonded, it is necessary to apply adhesive 1 in a ring shape to areas other than the recording area near the inner and outer peripheries. Therefore, a dispenser coat in which the adhesive 1 is discharged from a nozzle while rotating the substrate as shown in FIG. 1b) is suitable. If it is applied in the form of a ring to form a hollow structure, known coating methods such as screen printing, gravure printing, etc. are suitably used.

Next, in the bonding process, one of the two substrates, at least one of which has a recording layer formed thereon, and at least one of which is coated with an adhesive, is aligned by the outer periphery of the substrate. The substrate is fitted into the jig, and the other substrate is fitted in the same way, and the recording layer is placed on the inside, and the adhesive is cured while being fixed by the jig.

The first method is to bond two substrates together without misalignment.
As shown in Figure C), three ring-shaped bonding jigs in which the outer and inner diameters of the disks are the same are placed on a plate with good flatness and bonded together. A method using a bonding jig in which a similar ring is fixed in advance on a flat table, or a method using a bonding jig in which a similar ring is fixed in advance on a flat table, or a method in which multiple fins are combined at the center so that they do not overlap, although they are not ring-shaped, as shown in e). Any type of jig, such as a method using the alignment jig 3, may be used as long as the outer diameter of the disk can be determined accurately.

The inner diameter of the bonding jig 3 is preferably 0 to +0.2 mm smaller than the nominal value, more preferably 0 to +0.1 mm. This means that, for example, in the case of a disk with an outer diameter of 1301, the inner diameter of the bonding jig is preferably 130.0 to 130.2 m+*.

After the above-described bonding process, it is mounted so that the cross section shown in FIG. 2 is obtained. A) shows an example in which an adhesive layer 5 is further formed on the substrate on which the recording layer 4 is formed, and another substrate 2 is bonded to the substrate. This structure is easy to manufacture and has high practicality because it improves storage stability. b) The two substrates 2 on which the recording layer is formed are arranged so that the recording layer surfaces 4 facing each other face each other on the inside. An example is shown in which a spacer 6 is interposed and the adhesive layer 5 is bonded to form a hollow structure.

With this configuration, the recording layer 4 is isolated from the outside air without impairing its sensitivity, and can be protected from dust, scratches, contact with harmful gases, etc., thereby improving storage stability. Furthermore, in a method in which the recording layer 4 undergoes changes such as melting, decomposition, and evaporation by laser light to form bits, the surface of the recording layer 4 is free space, making it easy to form bits, and the thermal conductivity of air is Since the layer is much larger than the substrate, the diffusion of heat caused by laser light is small, improving recording sensitivity.

Furthermore, it is possible to record on both sides and is highly practical. c) is an example in which a substrate 2 on which a recording layer 4 is formed and a substrate 2 without a recording layer are formed into a hollow structure similarly to b).

As the spacer 6, any material such as resin, metal, ceramics, glass, etc. can be used as long as it is possible to maintain a constant distance between the two substrates. The structure shown in FIG. 2d) can be obtained by mixing granular substances 6' of the above material with roughly uniform particle sizes with an adhesive and applying the mixture together with the adhesive. In this case, Fig. 2 b), c)
It is much simpler and more practical than the one shown in Figure 2, which involves bonding ring-shaped spacers together. Also, Figure 2 e
), it is also possible to provide a convex portion on the inner and outer peripheral portion of the substrate 2 or to form a hollow structure.

The adhesive l used for the adhesive layer 5 may be a commonly used ultraviolet curing adhesive, thermosetting adhesive, solvent volatile adhesive, etc. as long as it does not invade the recording area of the recording layer 4.
Adhesive layers such as moisture-curing adhesives, hot-melt adhesives, two-component curing adhesives, etc. can be used. In particular, ultraviolet curable adhesives and two-component curable adhesives are preferably used in terms of workability and productivity.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to easily mount a bonded type disk without positional deviation, and prevent adhesive from protruding to the inner and outer peripheral edges due to axis misalignment.
Since it is possible to prevent the adhesive from entering the recording area near the outer periphery of the hollow structure, it is possible to provide an optical recording medium that has good center diameter accuracy, can increase information capacity, and can handle high speeds with less rotational unevenness. It is possible.

[Brief explanation of the drawing]

FIG. 1 is a process schematic diagram of an example according to the method of the present invention.
, b) shows the coating process, c), d), and e) show the bonding process, and FIG. 2 shows a cross-sectional view of the optical recording medium after bonding and mounting according to the present invention. 1 Adhesive 2 ゛Substrate 3 Bonding jig 4 Recording layer 5 Adhesive layer 6 Spacer 6° Particulate matter Patent applicant
Canon Co., Ltd. Agent Tadashi Wakabayashi Figure 1 Figure 2

Claims (2)

[Claims] (1) A step of applying adhesive to at least one of the two disk substrates, at least one of which has a recording layer for recording information using a laser beam, and then aligning the disk substrates using the outer periphery. 1. A method for producing an optical recording medium, comprising successively performing the steps of laminating two substrates using a laminating jig so that the recording layer is on the inside and curing an adhesive. (2) The method for manufacturing an optical recording medium according to claim 1, wherein the adhesive contains particulate matter.