JP3498816B2 - Optical disc manufacturing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical disk, and more particularly, to mounting a second resin substrate on a first resin substrate when bonding. The present invention relates to a method for manufacturing an optical disk in which air pockets, air bubbles, and the like are not generated between resin substrates as much as possible. 2. Description of the Related Art Today, the use of computers is widespread, and the development of their capacity, speed, etc. is remarkable. In particular, the memory density of the memory body has been dramatically improved, and this is giving an influence that changes common sense in daily life. Recording disks, especially optical disks, are the
It is compact and convenient to carry, and is used for many purposes for storage. An optical disk is made of a disc-shaped substrate made of a synthetic resin such as a polycarbonate resin. Signal pits, which are information signals, are recorded on the resin substrate.
On this signal pit, a reflection film of aluminum, nickel or the like is formed. 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 referred to as a UV resin) is formed. [0004] In order to record signals at a higher density of information, it is preferable that the thickness of the substrate is as thin as possible.
0.6 mm is adopted from the viewpoint of manufacturing restrictions and strength. Then, since the CD standard is about 1.2 mm in thickness, if it is attempted to conform to the standard, another resin substrate is further 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 disk 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, a substrate obtained by bonding two resin substrates naturally has a sufficient strength. That is, since the two optical discs are strong in strength and conform to the mainstream CD standard,
This is extremely advantageous from the viewpoint of versatility. The inventor of the present invention manufactures such an optical disk on which two resin substrates are bonded 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). The application in this case employs a method using an application roller, a discharge nozzle, a mandrel, or the like. After the adhesive is applied to the first resin substrate,
A second resin substrate is mounted thereon. After the second resin substrate is placed, the adhesive interposed between the two resin substrates is cured. For example, when an ultraviolet curable resin is used as the adhesive, ultraviolet light is applied during curing. When the adhesive is cured, the first resin substrate and the second resin substrate are surely integrated, and an optical disk that is firmly bonded is obtained. By the way, the present inventors, when placing the second resin substrate on the first resin substrate in such a bonding method, initially, the second resin substrate is made as small as possible with respect to the first resin substrate. It was placed so as to contact in parallel. However, it has been found that when placed in this manner, a large amount of air enters between the first resin substrate and the second resin substrate, and a phenomenon occurs in which 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 be generated. When the adhesive is hardened after the air pool is left inside as described above, the air is fixed as an independent pool or air bubble. Therefore, the optical disk formed by bonding the two resin substrates has air pockets and air bubbles remaining between the two substrates, so that the optical disk includes a partial weak point in terms of strength. Also, when viewed from the surface, air pockets and air bubbles are conspicuous, and the optical disc is disadvantageous in appearance. [0010] The present invention is directed to overcoming the problems set forth above. That is, an object of the present invention is to minimize air gaps and air bubbles between the two substrates when the second resin substrate is placed on the first resin substrate in the process of manufacturing an optical disc. It is an object of the present invention to provide a method for manufacturing an optical disk having excellent appearance. In order to solve such a problem, the present inventors examine the state of contact of the second resin substrate with the first resin substrate, and thereby determine the air condition in the mounting process. Did not enter, and the present invention was completed based on this finding. That is, the present invention provides a first method in which a signal is recorded.
A pressing portion which is coated with an ultraviolet curable resin on the resin substrate (U1), and which is disposed on the resin substrate (U1) so as to be biased downward at the center.
Material (2) and a plurality of materials arranged around it, inclined inward and downward
( 1) provided with a groove ( P ) having a lower surface ( P1 )
A second resin substrate (U2) is placed by a gripping device ( A ) having the following, and the ultraviolet-curable resin is cured by ultraviolet irradiation to integrate the two substrates;
When mounting the second resin substrate (U2) on the first resin substrate (U1), first , the inclination of the pressing member (2) and the groove ( P )
The second resin substrate ( U2 ) is bent downward by the lower surface ( P1 )
And then hold it in the first resin substrate ( U1 )
Positioned upwardly by the pressing member (2), and oppressive to be contacted with the pressing while the first resin substrate (U1) the central portion of the second resin substrate (U2), the first resin substrate (U 1) To
And gradually move the second resin substrate ( U2 ) outward from its center.
The present invention resides in a method of manufacturing an optical disk which is placed so as to come into contact with the optical disk. According to the present invention, the first resin substrate and the second resin substrate are in contact with each other outward from the center. As a result, air pools, air bubbles, and the like are forced to the outside, and almost no air remains between the resin substrates. Next, the present invention will be described based on the drawings with reference to the embodiments. FIGS. 13 (1) to 13 (5) schematically show steps of manufacturing an optical disc D by bonding two resin substrates. The steps will be briefly described below. First, first, the resin substrate U1 on which the signal is recorded
(First resin substrate) is placed (Step 1). Here, the receiving table C has a boss for positioning the resin substrate at the center and is rotatable (the boss is omitted in the figure). Next, the first place
After the resin substrate U1 is placed, an adhesive such as an ultraviolet ray curable resin is applied on the first resin substrate (Step 2). In the case where an ultraviolet-curable resin is used as the adhesive, it is preferable that the application is performed such that the adhesive is dripped from above the first resin substrate U1. For example, if the discharge nozzle 8 is moved while the first resin substrate U1 is rotated, it is possible to apply the adhesive in a spiral shape as shown in the figure. This spiral application is extremely advantageous from the viewpoint of preventing bubbles,
The details of this point are not essential to the present invention, and 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 mounting at this time is extremely important, and greatly affects the strength after bonding. Next, after the second resin substrate U2 is placed on the first resin substrate U1,
By rotating the cradle C, both are integrally rotated at a 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 so as to be evenly distributed. Furthermore, if the adhesive itself contains any bubbles, it is possible to completely release the bubbles by rotation at the same time. After the adhesive is spread, the adhesive is cured (5). When the adhesive is an ultraviolet curable resin, the adhesive is cured by irradiating ultraviolet light from above the second resin substrate U2 while rotating at a low speed (the ultraviolet light usually has a reflecting mirror 13 behind it). Irradiated by the ultraviolet irradiation source 12). The ultraviolet-curing resin is cured by receiving ultraviolet rays,
The first resin substrate U1 and the second resin substrate U2 are surely integrated, and an optical disk that is firmly bonded is completed.
When the adhesive is a hot-melt adhesive, the adhesive may be cured by air cooling or slow cooling without irradiation with ultraviolet rays. Through the above-described steps, the two resin substrates are bonded together via an adhesive and cured to form the optical disc D. As described above, in the process of bonding the optical discs, the adhesive is applied to the first resin substrate U1, and then the second resin substrate U2 is placed thereon. It is unique because it employs a special method of mounting. Hereinafter, this mounting method will be described. FIG. 1 shows a state in which the second resin substrate has not yet been gripped. At this time, the second receiving table C is in a state where the first resin substrate U1 is placed and the surface thereof is coated with the resin agent R. The second receiving table C has a structure in which the disc body C1 is
And a boss C3 at the center of the disk C1. In addition, the first receiving base B is in a state where the second resin substrate U2 carried by a robot hand or the like (not shown) is placed thereon. The first receiving base B has a disk B1 supported on a support shaft B2, and has a boss B3 at the center of the disk B1. Above the second resin substrate U2, the gripping device A is positioned and arranged. The gripping device A grips the second resin substrate U2 on the first receiving table B and moves up and down or pivots laterally.
Function as mounting means for mounting the first resin substrate U1 on the second receiving table C. Therefore, first, this gripping device A is
This will be briefly described with reference to FIG. The gripping device A is one in which the gripping body 1 is attached to a head portion 4 at the tip of a rotatable base body 6. The grip body 1 is movable in an outward or inward direction via a moving rod 5 driven by an air device (not shown). The base body 6 is also configured to move up and down and rotate to the left and right via a moving rod 7 by an air device (not shown). The gripper 1 has a pair of right and left grippers 1A, 1
B, 1C,..., And can hold the second resin substrate U2 at four positions. As shown in FIG. 10A, a groove P slightly larger than the thickness of the second resin substrate is provided in the grip portion, and a lower surface P1 of the groove P is formed in a tapered shape. For this reason, as described later, the second
When the resin substrate U2 is gripped, the resin substrate is slightly deformed by being pressed at the center by the pressing member 2, but the grip portion 1A can sufficiently allow it. FIG. 10B is a cross-sectional view in which the grip portion is cut at the groove. As shown in FIG. 10B, the outer peripheral surface of the second resin substrate U2 fitted in the groove P is It contacts the wall L. Since the rear wall L has an arc shape, the rear wall L can be accurately fitted on 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 mounting piece 3.
The pressing member 2 is attached to a mounting piece 3.
On the other hand, it is urged downward by the resilient spring 2A. The lower end of the pressing member 2 is connected to the second resin substrate U2
Is pressed in a ring shape, and presses around a boss provided at the center of the second receiving table C. FIG.
(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 C3, and the mutual arrangement of the resin substrates U1 and U2 at the time of pressing. It shows the relationship. Pressing the periphery of the boss C3 in a ring shape means that the periphery of the center hole H of the second resin substrate U2 is pressed 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. Using such a gripping device A, a placing operation as described below is performed. First, the holding device is lowered from the state shown in FIG. At this time, the pressing member 2 of the gripping device A
The periphery of the boss portion B3 of the first receiving table B is pressed. The holding body 1 stops at a position where it holds the second resin substrate U2 from the surroundings (FIG. 2). Here, the gripper 1 is moved inward to grip the second resin substrate U2 from the periphery (FIG. 2 → FIG. 3). Next, with the second resin substrate U2 gripped, the gripper 1 is raised (FIG. 3 → FIG. 4). When raised, the center of the second resin substrate U2 is
Pressed down. At this time, since the periphery is gripped and fixed by the gripper 1, the second resin substrate itself has a slightly curved state having a convex portion as shown in FIG. Then, the gripping device A is turned, that is, the base body 6 is rotated, and the gripper 1 is slid sideways and transferred onto the second receiving table C (FIG. 4 → FIG. 5). Thus, the second resin substrate U2 is located just above the first resin substrate U1. Next, the gripper 1 is lowered, and the first resin substrate U1 is moved to the second resin substrate U2.
Approach. Here, since the center 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 its center (FIG. 5).
→ Figure 6). That is, first, the pressing member 2 is positioned at the center of the second resin substrate U2 (in particular, in this case, around the center hole H of the second resin substrate, that is, around the boss C3 of the second receiving base C).
Is brought into pressure contact with the first resin substrate U1 (FIG. 1).
1). Next, in a state where the central portion is pressed and contacted, the gripper 1 is moved outward to move the periphery of the second resin substrate U2 to the gripper 1.
(Fig. 6-> Fig. 7). When the holding body 1 is separated from the second resin substrate U2, the second resin substrate U2 comes in contact outward from the pressed central portion. By contacting outward, air is sequentially pushed outward from the air pool in the small diameter portion region. Here, as described above, there are various methods for applying the adhesive. However, no matter what the state of application of the adhesive, as a result of performing such an operation, air is greatly prevented from entering between the resin substrates. Is done. Finally, the entire second resin substrate is brought into close contact with the first resin substrate, and the mounting is completed (FIG. 8). The transmission of this contact is performed by the elastic force of the second resin substrate U2, and is short in time.
Here, the gripper 1 moves upward and laterally by the raising 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 placing operation by the gripping body 1 as described above has been performed when the gripping portions of the gripping body 1 are four places. However, the number of gripping portions by the gripping body 1 is not limited to this. FIG. 12 schematically shows some examples. FIG. 3A shows an example in which the grip portion 1A has two locations. As described above, when the second resin substrate U is gripped at two places,
2 tends to be folded so that it is folded in two at the line connecting the gripping portions 1A. Therefore, it is preferable to use more than two places. FIG. 4B shows an example in which the number of grips 1A is three. (C) shows an example in which there are eight gripping portions 1A. In this case, the periphery of the second resin substrate U2 is evenly gripped, for example, in a state close to the circumference, so that 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 accurately brought into contact with the first resin substrate U1 outward from the center. Therefore, at this time, the action of pushing the air outward becomes more effective. Thus, it can be understood that it is preferable that the portion to be gripped by the gripping body 1 is physically as large as possible. Although the present invention has been described above, the present invention is not limited only to the embodiments, and various modifications can be made without departing from the essence thereof. For example, the shape of the distal end portion of the pressing member 2 can be deformed within a range in which the purpose is achieved, and the same can be said for the shape of the grip portion. The present invention has the following advantages since it has the above-described configuration. 1. Air (air accumulation, air bubbles, etc.) hardly enters between the first resin substrate and the second resin substrate. 2. An optical disc having uniform strength is obtained. 3. There is no accumulation of air and no air bubbles, and the optical disc becomes uniform in appearance.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a state diagram of a mounting procedure of a resin substrate. FIG. 2 is a state diagram of a mounting procedure of a resin substrate. FIG. 3 shows a state diagram of a mounting procedure of a resin substrate. FIG. 4 shows a state diagram of a mounting procedure of a resin substrate. FIG. 5 shows a state diagram of a mounting procedure of a resin substrate. FIG. 6 shows a state diagram of a mounting procedure of a resin substrate. FIG. 7 shows a state diagram of a mounting procedure of a resin substrate. FIG. 8 shows a state diagram of a procedure for placing a resin substrate. FIG. 9 is a diagram illustrating a mounting device. FIG. 10 (a) is an enlarged side view of a grip portion of the mounting device. FIG. 10B is an enlarged top view of the grip portion of the mounting device. FIG. 11A is a diagram illustrating a state where a pressing member is pressing. FIG. 11B is a diagram illustrating a state of the pressing portion. FIG. 12 is a modified example of an arrangement position of a grip portion. FIG. 13 is a simplified state diagram showing the sequence of a method for manufacturing an optical disk. FIG. 14 is a diagram illustrating an optical disc in which two resin substrates are bonded together. [Description of Signs] 1 ... Grip body 1A ... Grip portion 1B ... Grip portion 2 ... Pressing member 2A ... Spring spring 3 ... Mounting piece 4 ... Head portion 5 ... Rod 6 ... Base body 7 ... Rod 7 ... Rod 8 ... Discharge Nozzle 12 UV irradiation source 13 Concave reflector A Gripping device B First pedestal B1 Disk body B2 Support shaft B3 Boss C Second pedestal C1 Disk body C2 Support shaft C3 Boss Part H Central hole L Rear wall P Groove P1 Lower surface R Adhesive (ultraviolet curable resin) T Contact part U1 First resin substrate U2 Second resin substrate

Claims (1)

(57) [Claim 1] A first resin substrate (U1) on which a signal is recorded
The ultraviolet-curing resin is applied, thereon downwardly in the central portion
A pressing member (2) arranged to be urged, and
A plurality of lower surfaces ( P1 ) that are arranged in
Holding device provided with a holding body (1) provided with a groove ( P ) having
Placing the location second resin substrate by (A) (U2), by ultraviolet irradiation method of manufacturing an optical disc to integrate both substrates by curing the ultraviolet curable resin, the first resin substrate (U
When placing the second resin substrate (U2) on 1), first
The serial pressing member (2) and the inclined bottom surface of the groove (P) (P 1)
Holding the second resin substrate ( U2 ) in a downwardly curved shape
And then position it above the first resin substrate ( U1 )
The second resin substrate (U2) is formed by the pressing member (2 ).
The first resin substrate (U1) while pressing the center of the
To the first resin substrate ( U1 ) and the second resin
The substrate ( U2 ) is gradually in contact with the outside from its center
A method for manufacturing an optical disk, comprising: