JPH08293131A - Production of optical disk - Google Patents

Abstract

PURPOSE: To eliminate the air pockets and bubbles between a first resin substrate and a second resin substrate and to obtain an optical disk uniform in terms of strength by applying an adhesive on the first substrate and placing the second substrate thereon in such a manner that both substrates come into contact with each other successively from the central part to the outer side in production of the optical disk. CONSTITUTION: The resin substrate U1 recorded with signals is placed on a rotatable receiving base C and the adhesive is applied thereon. The resin substrate U2 held on the receiving table B is handed to a turnable and freely vertically movable holding device A and is placed in a curved state onto the substrate U1. The pressing member 2 of the holding device A presses the central part of the substrate U2 to bring the substrate into contact with the central part of the substrate U1. The holding body is moved outward and is disengaged from the circumference of the substrate U2, by which both resin substrate are brought into contact with each other outward from the central part. As a result, the air is extruded outward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical disk, and more specifically, when a second resin substrate is placed on a first resin substrate during bonding, an air trap is formed between both resin substrates. The present invention relates to a method for manufacturing an optical disc in which air bubbles and the like are not generated as much as possible.

[0002]

2. Description of the Related Art Today, computers are used in all fields, and development of capacity, speed, etc. is remarkable. In particular, the memory density of the memory body has been dramatically improved, and the effect of changing common sense in daily life is being exerted. Of the storage media, recording discs, especially optical discs,
It is compact and convenient to carry, and is used in many applications for storage.

An optical disk is made of a disk-shaped substrate made of synthetic resin such as polycarbonate resin. A signal pit, which is an information signal, is recorded on the resin substrate,
A reflective film of aluminum, nickel or the like is formed on the signal pits. And on this reflective film,
In order to protect the signal pits, for example, a protective resin material such as an ultraviolet curable resin (commonly called UV resin) is formed.

By the way, it is preferable that the thickness of the substrate is as thin as possible in order to increase the density of information and record signals.
0.6 mm is adopted from the viewpoint of manufacturing restrictions and strength. Since the standard of CD is about 1.2 mm in thickness, if it is attempted to match it, another resin substrate will be bonded to the above resin substrate. For example, the optical disk shown in FIG. 14 shows a structure in which two resin substrates are bonded together.

That is, the optical disc 1D has a first resin substrate 2 having a reflection film 3D and a protective resin material 4D formed on signal pits.
D and the second resin substrate 6D are bonded together with an adhesive 5D and cured. As described above, the one obtained by sticking two resin substrates together can naturally have sufficient strength. That is, the two optical discs bonded together are strong in strength and conform to the mainstream CD standard.
It is extremely advantageous from the viewpoint of versatility.

The present inventors have manufactured such an optical disc in which two resin substrates are bonded together by the following method. First, a resin substrate on which a signal is recorded (first
An adhesive, for example, an ultraviolet curable resin is applied to the resin substrate). For coating in this case, a method using a coating roller, a discharge nozzle, a mandrel, or the like is adopted.

After the adhesive is applied to the first resin substrate,
The second resin substrate is placed on it. After the second resin substrate is placed, the adhesive agent interposed between both resin substrates is cured. For example, when an ultraviolet curable resin is used as the adhesive, ultraviolet rays are applied during curing. When the adhesive is cured, the first resin substrate and the second resin substrate are surely integrated, and an optical disc in which they are firmly bonded together can be obtained.

By the way, when the second resin substrate is placed on the first resin substrate in the bonding method as described above, the second resin substrate is initially placed on the first resin substrate as much as possible. They were placed so that they contacted each other in parallel. However, it has been found that such a placement causes a phenomenon in which a large amount of air enters between the first resin substrate and the second resin substrate and the air is trapped in the adhesive.

Particularly, in the area of the small diameter portion of the optical disk, many air pockets and air bubbles are likely to occur. If the air reservoir is left inside in this way and then the adhesive is hardened, the air is fixed as independent reservoirs or air bubbles. Therefore, the optical disk formed as a result of bonding the two resin substrates has a partial weak point in strength as a result of air pockets and air bubbles remaining between the two substrates. Also, when viewed from the surface, air pockets and air bubbles are conspicuous, and the appearance of the optical disk is disadvantageous.

[0010]

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems. That is, an object of the present invention is to prevent air pockets and air bubbles from entering between the two substrates when placing the second resin substrate on the first resin substrate during the optical disc manufacturing process. It is an object of the present invention to provide a method for manufacturing an optical disc that is excellent in appearance.

[0011]

However, the inventors of the present invention have examined the contact state of the second resin substrate with the first resin substrate to prevent air from entering during the mounting process. The present invention has been completed based on this finding.

That is, according to the present invention, an adhesive is applied to a first resin substrate on which signals are recorded, a second resin substrate is placed on the first resin substrate, and the adhesive is cured to integrate the two substrates. A method of manufacturing an optical disc, wherein when mounting a second resin substrate on a first resin substrate, the second resin substrate is mounted on the first resin substrate so that the second resin substrate gradually contacts the center portion of the first resin substrate to the outside. And a method for manufacturing an optical disc. The second resin substrate is in a method for manufacturing an optical disc in which a signal is recorded on the resin substrate.

Further, the first resin substrate on which the signal is recorded is coated with an ultraviolet curable resin, the second resin substrate is placed on the first resin substrate, and the ultraviolet curable resin is cured by irradiation of ultraviolet rays to integrate the two substrates. A method of manufacturing an optical disc that is becoming
The present invention resides in a method of manufacturing an optical disc in which, when the second resin substrate is placed on the first resin substrate, the second resin substrate is placed on the first resin substrate so that the second resin substrate gradually contacts the outside from the center portion thereof. In addition, the second resin substrate is also a method of manufacturing an optical disc in which a signal is recorded on the resin substrate.

Further, an ultraviolet curable resin is applied to the first resin substrate on which a signal is recorded, a second resin substrate is placed on the first resin substrate, and the ultraviolet curable resin is cured by irradiation of ultraviolet rays to integrate the two substrates. A method of manufacturing an optical disc that is becoming
A method of manufacturing an optical disk is one in which, when the second resin substrate is placed on the first resin substrate, the central portion of the first resin substrate is elastically pressed and brought into contact with the second resin substrate to be placed. In addition, the second resin substrate is also a method of manufacturing an optical disc in which a signal is recorded on the resin substrate.

Also, a step of placing a first resin substrate on which a signal is recorded on a pedestal, a step of applying an adhesive to the first resin substrate, and a second resin substrate on the first resin substrate The method for producing an optical disc includes a step of placing the parts while keeping them in contact with each other toward the outside, and a step of curing the adhesive.

Further, a step of placing the first resin substrate on which a signal is recorded on a pedestal having a positioning boss at the center, and a step of pressing the second resin substrate toward the outside while pressing the peripheral portion of the boss first. A method of manufacturing an optical disc includes a step of placing the pieces in contact with each other and a step of curing the adhesive.

Further, the present invention also resides in a method of manufacturing an optical disk in which the adhesive is an ultraviolet curable resin. In addition, the second resin substrate is also a method of manufacturing an optical disc in which a signal is recorded on the resin substrate.

[0018]

According to the present invention, since the first resin substrate and the second resin substrate are in contact with each other from the center toward the outside, air pockets, bubbles, etc. can be driven out to the outside. Little air remains between the substrates.

[0019]

The present invention will be described below with reference to the accompanying drawings. 13 (1) to 13 (5) schematically show steps of manufacturing an optical disc D by bonding two resin substrates together. The steps will be briefly described below. First of all, first, the resin substrate U1 in which a signal is recorded on the receiving table 7.
A (first resin substrate) is placed (step 1).

Here, the pedestal C has a boss portion for positioning the resin substrate in the center and is rotatable (the boss portion is omitted in the figure). Next, the first on the cradle C
After the resin substrate U1 is placed, an adhesive such as an ultraviolet ray curable resin is applied onto the first resin substrate (step 2). When the adhesive uses an ultraviolet curable resin, it is preferable that the application is performed by dropping the adhesive from the first resin substrate U1.

For example, if the discharge nozzle 8 is moved while the first resin substrate U1 is rotated, the adhesive can be applied in a spiral shape as shown in the figure. This spiral coating is extremely advantageous from the viewpoint of preventing bubbles,
Since the details of this point are not essential to the present invention, they are omitted here. After the adhesive is applied to the first resin substrate U1, the second resin substrate U2 is placed thereon (step 3).

The manner of placement at this time is extremely important and greatly affects the strength after the attachment. Next, after the second resin substrate U2 is placed on the first resin substrate U1,
When the pedestal C is rotated, both are integrally rotated at high speed (4). That is, by this rotation, the first
The adhesive interposed between the resin substrate U1 and the second resin substrate U2 is spread evenly and evenly.

Furthermore, if the adhesive itself contains even a small amount of air bubbles, it is possible at the same time to let it escape completely to the outside by rotation. After spreading the adhesive, the adhesive is cured (5). When the adhesive is an ultraviolet curable resin, the adhesive is cured by irradiating it with ultraviolet light from above the second resin substrate U2 while rotating it at a low speed (here, the ultraviolet light is usually provided with a reflecting mirror 13 behind it). Is irradiated by the ultraviolet irradiation source 12).

The ultraviolet curable resin is cured by receiving ultraviolet rays,
The first resin substrate U1 and the second resin substrate U2 are surely integrated with each other, and a firmly bonded optical disc is completed.
When the adhesive is a hot-melt type adhesive, ultraviolet irradiation is not performed, and the adhesive may be cured by air cooling or slow cooling. Through the steps described above, the two resin substrates are bonded and cured with the adhesive, and the optical disc D is obtained.

As described above, the adhesive is applied to the first resin substrate U1 and then the second resin substrate U2 is placed on the first resin substrate U1 in the process of bonding the optical disks. It is unique because it uses a special method for mounting. Hereinafter, a method of placing this will be described.

FIG. 1 shows a state where the second resin substrate is not yet gripped. At this time, the second cradle C is in a state in which the first resin substrate U1 is placed and the resin agent R is applied to the surface thereof. In the second cradle C, the disc body C1 has a support shaft C2.
The disk body C1 is provided with a boss portion C3 at the center thereof. Further, the first cradle B is in a state in which the second resin substrate U2 carried by a robot hand or the like not shown is placed.

In this first cradle B, a disc body B1 is supported by a support shaft B2, and a boss portion B3 is provided at the center of the disc body B1. The gripping device A is positioned and arranged above the second resin substrate U2. The gripping device A grips the second resin substrate U2 on the first pedestal B and moves vertically or rotationally laterally. The second resin substrate U2
To function as a mounting means for mounting on the first resin substrate U1 on the second cradle C.

Therefore, first, here, the gripping device A is
A brief description will be given with reference to FIG. In the gripping device A, the gripping body 1 is attached to the head portion 4 portion ahead of the rotatable base body 6. The grip body 1 is movable outward or inward through a moving rod 5 driven by an air device (not shown). The base body 6 is also configured to move up and down and turn left and right via a moving rod 7 by an air device (not shown).

The gripping body 1 is composed of a pair of left and right gripping portions 1A and 1A.
B, 1C ... Are provided and the second resin substrate U2 can be held at four places. As shown in FIG. 10A, the grip portion is provided with a groove P slightly larger than the thickness of the second resin substrate, and the lower surface P1 of the groove P is formed in a tapered shape. Therefore, as described below,
When the resin substrate U2 is gripped, the pressing member 2 presses the central portion of the resin substrate U2 to deform the resin substrate to some extent, but the gripping portion 1A can sufficiently tolerate it.

FIG. 10 (b) is a sectional view of the gripping portion taken along the groove. As shown in this figure, the outer peripheral surface of the second resin substrate U2 fitted in the groove P is Abut the wall L. Since the rear wall L has an arc shape, it can be accurately fitted to the outer peripheral surface of the second resin substrate U2.
On the other hand, the pressing member 2 is attached to the bed 6 via the attachment piece 3.
Is attached, and the pressing member 2 is attached to the attachment piece 3
On the other hand, it is urged downward by the elastic spring 2A.

The lower end of the pressing member 2 has a second resin substrate U2.
Is shaped like a ring, and presses around the boss portion provided at the center of the second cradle C. Figure 11
(A) shows a state in which the first resin substrate and the second resin substrate are overlapped and pressed by the pressing member, and the pressing member 2, the boss portion C3, and the two resin substrates U1 and U2 are arranged relative to each other at the time of pressing. It shows the construction relationship. Pressing the periphery of the boss portion C3 in a ring shape means pressing the periphery of the central hole H of the second resin substrate U2 from above.

Second resin substrate U with respect to first resin substrate U1
The contact portion T of No. 2 also has a ring shape as shown in FIG. By using such a gripping device A, a mounting operation as described below is performed. First, the gripping device descends from the state of FIG. At this time, the pressing member 2 of the gripping device A is
The periphery of the boss portion B3 of the first cradle B is pressed.

Further, the grip body 1 stands by at a position where the second resin substrate U2 is gripped from the surroundings and stops (FIG. 2). Here, the grip body 1 is moved inward to grip the second resin substrate U2 from the surroundings (FIG. 2 → FIG. 3). Next, with the second resin substrate U2 being held, the holding body 1 is raised (FIG. 3 → FIG. 4). When raised, the central portion of the second resin substrate U2 will move to the pressing member 2
Can be pushed down with.

At this time, since the periphery is gripped and fixed by the grip body 1, the second resin substrate itself is in a slightly curved state having a downward convex portion as shown in FIG. Then, the gripping device A is swung, that is, the base body 6 is rotated, and the gripping body 1 is laterally slid and transferred onto the second cradle C (FIG. 4 → FIG. 5). With this, the second resin substrate U2 is positioned just above the first resin substrate U1. Next, the gripping body 1 is lowered so that the first resin substrate U1 is placed on the second resin substrate U2.
To approach.

Since the central portion of the second resin substrate U2 is pressed and slightly lowered, the second resin substrate U2 first comes into contact with the first resin substrate U1 from the central portion (FIG. 5).
→ Figure 6). That is, first, the pressing member 2 is first in the central portion of the second resin substrate U2 (in particular, in this case, around the central hole H of the second resin substrate, that is, around the boss portion C3 of the second cradle C).
Is pressed into contact with the first resin substrate U1 (see FIG. 1).
1). Next, in a state where the central portion is in pressure contact, the grip body 1 is moved outward to move the periphery of the second resin substrate U2 to the grip body 1.
Remove from (Figure 6 → Figure 7).

When the gripping body 1 is separated from the second resin substrate U2, the second resin substrate U2 comes in contact with the center portion being pressed outward in the outward direction. By making contact with each other in the outward direction, air is sequentially pushed outward from the air pool in the small diameter region. Here, as described above, there are various methods of applying the adhesive agent, but no matter what the application state, as a result of such an action, air is largely prevented from entering between the resin substrates. To be done.

Finally, the entire second resin substrate is brought into close contact with the first resin substrate to complete the mounting (FIG. 8). The transmission of this contact is performed by the elastic force of the second resin substrate U2, which is a short time.
Here, the gripping body 1 is lifted and laterally moved by the lifting and rotating drive of the gripping device A, and is positioned and arranged above the first cradle B which is the original position. Hereinafter, such an operation is repeated.

By the way, the mounting operation by the gripping body 1 as described above is the case where the gripping portion of the gripping body 1 is at four positions. However, the number of grips by the grip body 1 is not limited to this. FIG. 12 schematically shows some examples thereof.

(A) shows an example in which there are two grips 1A. In this way, when gripped at two places, the second resin substrate U
Since the force tends to act so that 2 is folded in two at the line connecting the gripping portions 1A, it is preferable that the number is more than 2 places.

(B) shows an example in which there are three grips 1A. (C) shows an example in which the grip portion 1A has eight positions. In this case, the circumference of the second resin substrate U2 is evenly gripped, for example, in a state close to the circumference. Therefore, when the pressing member 2 presses the center, the whole is deformed into a conical shape.

As a result, the second resin substrate U2 can be brought into proper contact with the first resin substrate U1 from the center toward the outside. Therefore, at this time, the action of pushing the air outward becomes more effective. As described above, it can be understood that it is preferable that the gripping body 1 is physically gripped as much as possible.

Although the present invention has been described above, the present invention is not limited to the embodiments, and various modifications can be made without departing from the essence thereof. For example, the shape of the tip portion of the pressing member 2 can be modified within the range where the purpose is achieved, and the shape of the grip portion is the same.

[0043]

Since the present invention has the above-mentioned structure, it has the following merits. 1. It is difficult for air (air traps, bubbles, etc.) to enter between the first resin substrate and the second resin substrate. 2. The optical disk has a uniform strength. 3. There are no air traps and bubbles, and the optical disc is uniform in appearance.

[Brief description of drawings]

FIG. 1 is a state diagram of a resin substrate mounting procedure.

FIG. 2 shows a state diagram of a mounting procedure of a resin substrate.

FIG. 3 is a state diagram of a resin substrate mounting procedure.

FIG. 4 is a state diagram of a placement procedure of a resin substrate.

FIG. 5 shows a state diagram of a placement procedure of a resin substrate.

FIG. 6 shows a state diagram of a procedure for placing a resin substrate.

FIG. 7 is a state diagram of a resin substrate mounting procedure.

FIG. 8 shows a state diagram of a placement procedure of a resin substrate.

FIG. 9 is a diagram showing a placing device.

FIG. 10A is an enlarged side view of a grip portion of the placement device. FIG. 10B is an enlarged top view of the grip portion of the placement device.

FIG. 11A is a diagram showing a state in which a pressing member is pressing. FIG. 11B is a diagram showing a state of the pressing portion.

FIG. 12 is a modification of the arrangement position of the grip portion.

FIG. 13 is a simplified state diagram showing the sequence of the optical disc manufacturing method.

FIG. 14 is a diagram showing an optical disc in which two resin substrates are bonded together.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Gripping body 1A ... Gripping part 1B ... Gripping part 2 ... Pressing member 2A ... Elastic spring 3 ... Attachment piece 4 ... Head part 5 ... Rod 6 ... Base body 7 ... Rod 7 ... Rod 8 ... Discharge nozzle 12 ... UV irradiation Source 13 ... Concave reflecting mirror A ... Gripping device B ... First pedestal B1 ... Disk body B2 ... Support shaft B3 ... Boss part C ... Second cradle C1 ... Disk body C2 ... Support shaft C3 ... Boss part H ... Center hole L ... Rear wall P ... Groove P1 ... Lower surface R ... Adhesive (ultraviolet curing resin) T ... Contact portion U1 ... First resin substrate U2 ... Second resin substrate

Claims (10)

[Claims] 1. A method of manufacturing an optical disk, wherein an adhesive is applied to a signal-recorded first resin substrate, a second resin substrate is placed thereon, and the adhesive is cured to integrate the two substrates. In mounting the second resin substrate on the first resin substrate, the second resin substrate is mounted on the first resin substrate so that the second resin substrate gradually contacts the outside from the central portion thereof. Optical disk manufacturing method. 2. The method of manufacturing an optical disc according to claim 1, wherein the second resin substrate is a resin substrate on which signals are recorded. 3. A first resin substrate on which a signal is recorded is coated with an ultraviolet curable resin, a second resin substrate is placed on the first resin substrate, and the ultraviolet curable resin is cured by irradiation of ultraviolet rays to integrate the two substrates. A method of manufacturing an optical disc, wherein when mounting the second resin substrate on the first resin substrate, the second resin substrate is mounted on the first resin substrate such that the second resin substrate gradually contacts the outside from the center thereof. Optical disc manufacturing method 4. The method of manufacturing an optical disc according to claim 3, wherein the second resin substrate is a resin substrate on which signals are recorded. 5. An ultraviolet curable resin is applied to a first resin substrate on which a signal is recorded, a second resin substrate is placed on the first resin substrate, and the ultraviolet curable resin is cured by irradiation of ultraviolet rays to integrate the two substrates. A method of manufacturing an optical disk, comprising placing the second resin substrate on the first resin substrate while contacting the second resin substrate while elastically pressing the central portion of the first resin substrate. Of manufacturing an optical disc characterized by: 6. The method of manufacturing an optical disc according to claim 5, wherein the second resin substrate is a resin substrate on which signals are recorded. 7. A step of placing a first resin substrate on which a signal is recorded on a pedestal, a step of applying an adhesive to the first resin substrate, and a second resin substrate on the first resin substrate at a central portion thereof. A method for manufacturing an optical disc, comprising: a step of placing the adhesive from the outside toward the outside, and a step of curing the adhesive. 8. A step of placing a signal-recorded first resin substrate on a pedestal having a positioning boss at the center, and a second step.
A method for manufacturing an optical disk, comprising: a step of placing a resin substrate so that the resin substrate is brought into contact with the periphery of the boss first while facing outward, and a step of curing an adhesive. 9. The method of manufacturing an optical disk according to claim 7, wherein the adhesive is an ultraviolet curable resin. 10. The method of manufacturing an optical disk according to claim 7, wherein the second resin substrate is a resin substrate on which signals are recorded.