JP2700699B2 - Method of manufacturing disc-shaped information recording substrate - Google Patents

Description

Description: TECHNICAL FIELD [0001] The present invention relates to a method for manufacturing a disc-shaped information recording substrate, and in particular, hardly any defective products are generated in a press step of pressing a plurality of disc-shaped substrates. The present invention relates to a method for manufacturing a disc-shaped information recording substrate having a high yield.

[Problems to be solved by conventional technology and invention]

2. Description of the Related Art Disc-shaped information recording substrates such as optical disks have been put to practical use in conjunction with the demand for paperless recording because of their extremely large recording capacity.

The disc-shaped information recording substrate is used to protect the recording layer that controls writing and reading of information, for example, between disc-shaped information recording bases on which recording layers are formed, or between disc-shaped information recording layers on which recording layers are formed. The disk-shaped information recording substrate on which the recording layer is not formed is bonded to a substrate in advance by using an adhesive, and is pressed by using a pressing unit.

Conventionally, a hydraulic press such as a hydraulic press or a pneumatic press has been used as a pressing means.

FIG. 5 is a front view of a hydraulic press used in a conventional crimping method.

In the figure, a hydraulic press 51 includes a copper movable press 52 having a flat and circular press surface,
A support member 53 for supporting the vertical press, a copper fixed press 54 having a flat and circular press surface, and the fixed press 54
And a fixing member 55 for fixing and supporting.

The movable press 52 and the fixed press 54 are arranged with their press surfaces facing each other so that the axes of their press axes coincide with each other, and the press surfaces of both presses 52 and 54 are An elastic sheet 56 made of silicone rubber is bonded so that a uniform rolling force is applied.

In the hydraulic press 51 having the above-described configuration, the material to be pressed W formed by laminating a plurality of disk-shaped substrates via an adhesive, which is produced in the previous step, is placed at the center of the press surface of the fixed press 54, When the movable press 52 is lowered by driving a hydraulic cylinder (not shown) to be attached, and pressed for a predetermined time in a state where a predetermined pressure is applied to the material W to be crimped, the adhesive action of the adhesive is strongly exhibited, and Are crimped and integrated.

The air press system is common to the above-described hydraulic press system in that fluid pressure is used, except that the power medium is different.

However, the above-mentioned conventional manufacturing method using a fluid pressure press has a problem in that defective products having defects such as warpage, inclination, splitting, and the incorporation of air frequently appear with difficulty in reading well. In order to find out the cause, the disk pressure of 10 kg / cm ² was increased by using the hydraulic press 51 shown in FIG.
The pressure distribution in the case of applying the pressure for 2 seconds was examined by pressing a pressure measurement film (trade name “Prescale Ultra Low Pressure”, manufactured by Fuji Photo Film Co., Ltd.).

FIG. 6 shows the pressure measurement film at that time, and in the drawing, the shade of the color indicates the magnitude of the pressure applied to the portion. As is clear from the figure, the density is remarkable, and it can be seen that the pressure is not uniformly applied to the material to be compressed. Next, consider why the pressure is not applied uniformly.

Returning to FIG. 5, when the cylinder device is driven, the press shaft 52a of the movable press 52 is supported by the hole 53a of the support member 53 and moves up and down. A predetermined gap is provided between the press shaft 52a and the hole 53a to enable the vertical movement.

Therefore, no matter how the upper and lower presses 52 and 54 are arranged so that the axes of the press shafts coincide with each other, a slight deviation occurs between the both axes when viewed from a microscopic viewpoint. Although such a deviation is very small, it cannot be neglected in the pressure bonding of the information recording base material which requires a precision on the order of microns. This is the reason why defective products having warpage, inclination, and the like frequently appear in the conventional method.

In addition, in the conventional method, there is a possibility that air may be mixed between the substrates during the pressing.

Furthermore, since there is an aspect that it is difficult to incorporate into a continuous production line, it does not conform to the modern direction in which labor saving and automation of the production line are actively called, and there is also a problem in terms of production efficiency.

For this reason, recently, as a pressing means of the disk-shaped substrate,
There has been newly proposed a method of using a roll press having at least one pair of pressure rolls instead of the fluid pressure press.

According to the method by the roll press machine, by arranging the axes of the pair of pressure bonding rolls in parallel with each other,
It is possible to prevent defects such as inclination from occurring. In addition, in this method, the disc-shaped base material is sequentially pressed and pressed while releasing air between the base materials, so that air is less likely to be mixed between the base materials during the pressing. Furthermore, it is advantageous in that automation can be achieved because it can be easily incorporated into a continuous production line.

However, in this method, misalignment is likely to occur between the disk-shaped substrates at the time of pressure bonding. The misalignment may cause a disc rotation failure which causes a reduction in movement during recording and reproduction.

As a solution to the above-described problem in the case of using a roll press machine, a method using a multi-stage roll press machine in which the press pressure applied to the disc-shaped base material is small in the initial stage of the press and gradually increased thereafter. It has been proposed (JP-A-63-13147). According to this method, since the pressing pressure in the initial stage of the press in which the adhesion between the disk-shaped substrates is insufficient is small, the positional displacement hardly occurs.

However, since there is usually a difference in the rotational force between the upper and lower rolls of the pressure roll, even if the press pressure in the initial stage of the press is reduced, it is not possible to effectively prevent displacement.
In particular, when the disc-shaped base material is fed with a slight inclination with respect to the clearance between the pressure-bonding rolls, misalignment is likely to occur.

Further, since a multi-stage roll press is required, a great deal of expense is required to prevent misalignment, and a considerably large space is required for the pressing process. This method is difficult to adopt when the space for the pressing process is small.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a manufacturing method capable of manufacturing a disc-shaped information recording substrate with a small positional deviation even in a small space at a low cost and with a high yield. is there.

[Means for solving the problem]

In order to achieve the above object, a method of manufacturing an information recording substrate according to the present invention is a roll press including a plurality of disc-shaped substrates superposed with an adhesive interposed between the substrates, and at least a pair of pressure rolls. In manufacturing a disc-shaped information recording substrate by pressing with a machine, the plurality of disc-shaped bases have through holes having a diameter slightly larger than the diameter of the plurality of disc-shaped bases, and the plurality of discs After being housed in a holder having a body slightly thinner than the base material, a bottom flexible film for closing the bottom of the through-hole, and an upper flexible film for closing the top of the through-hole openably and closably, The paper is fed to the roll press machine.

[Action]

In the method of the present invention, when the holder holding the disc-shaped base material is fed to a roll press machine, the disc-shaped base material is sequentially squeezed from the front end and pressed while releasing air between the base materials. At this time, since the disc-shaped base material is pressure-bonded while being housed in the holder, even if the holder is fed with a slight inclination with respect to the clearance between the pressure rolls, the disc-shaped base material is misaligned. It is unlikely to occur. In addition, since the disc-shaped base material is stored in the holder and fed, the feeding is easy, and the pressure roll and the disc-shaped base material are unlikely to be damaged or contaminated.

〔Example〕

Hereinafter, the present invention will be described based on examples. However, the present invention is not limited to the following examples, and can be appropriately modified and implemented without changing the gist thereof.

FIG. 1 shows an example of a roll press machine as a pressing means for carrying out a method for manufacturing a disc-shaped information recording substrate according to the present invention. The roll press machine 1 has a predetermined distance, for example, 2.4 mm thickness. When the disk-shaped substrate is pressure-bonded, the disk-shaped substrate is usually composed of a pair of upper and lower pressure-bonding rolls 11, 12 arranged in parallel at a distance of about 2.2 to 2.65 mm and a drive motor (not shown).

The press rolls 11 and 12 are made of a material to be pressed (a disk-shaped base material) W
It is configured so that the roll interval (clearance) can be adjusted according to the thickness, the desired rolling force, etc., and the rolling force is uniformly applied to the material W to be pressed on the peripheral surface of each of the pressure rolls. An elastic member such as silicone rubber having a thickness of about 1 to 5 mm is stretched. The main bodies of the pressure rolls 11 and 12 are made of a hard material such as steel.

Both ends of each of the roll shafts 11a and 12a of the pressure bonding rolls 11 and 12 are supported by support means (not shown) and connected to a drive motor, and the drive motor drives the cover to be fed from the left side in the figure. The crimping material W is configured to be able to be discharged to the right in the figure while being crimped.

The roll length of each of the pressure rolls 11 and 12 is
If the thickness, strength, etc. of a and 12a are sufficient, there is no particular limitation, but care should be taken because unnecessarily long rolls may be bent and may not be uniformly reduced.

Using the roll press machine 1 as described above, the information recording substrate
In order to manufacture a CD, first, after adjusting the clearances of the pressure-bonding rolls 11 and 12 so that an appropriate rolling force is applied to the material-to-be-pressed W, a motor is moved and both rolls are rotated. 1 is brought into a state capable of being crimped.

Next, the material W to be crimped is placed on both pressure rolls 1 from the left side in the figure.
It is fed between 1, 12 and discharged to the right in the figure while being pressed by the pressing force and rotational force of both pressing rolls.

FIG. 2 is a cross-sectional view showing an example of the material to be press-bonded W, in which a recording layer 22 having a thickness of 1000 to 3000 mm is compressed on one surface of a base material 21 made of polycarbonate or the like having a concave portion. Molding, injection molding, 2P method, etc., a conventionally known method, an aluminum thin film 23 as a light reflecting plate is formed thereon by sputtering or the like, and a thickness of 3 to 20 μm is further formed thereon.
For the production of an information recording board of 2.4mm thickness, two protective films 24 each having a degree of protection are formed, and each protective film 24 is coated with an epoxy, ultraviolet curable, acrylic, etc. The substrate S.

In the manufacturing method according to the present invention, a specific holder is used when the information recording substrate manufacturing base material S is fed to a roll press machine. In addition, the feeding of the holder to the roll press machine,
It may be performed continuously using a transport roll, a conveyor or the like.

FIG. 3 shows an example of a holder used in the method of the present invention. In the figure, a holder 31 has a main body 32 having a through hole having a diameter slightly larger than the diameter of the material to be pressed W at the center, a bottom flexible film 33 for closing the bottom of the through hole, and an upper part of the through hole. It is composed of an upper flexible film 34 that can be opened and closed freely, and is configured to be able to accommodate the material to be pressed W in the formed hole. The body 32 is formed to be slightly thinner than the material W so that the material W can be pressed. By using such a holder, it is possible to effectively prevent the material W to be crimped from being squeezed while passing between the rolls and causing misalignment between the base materials that have been preliminarily aligned and overlapped. At the same time, the supply of the material to be compressed W to the roll press machine 1 is facilitated.

Further, the holding tool 31 may be formed in a belt shape, a plurality of crimped material receiving portions may be provided, and the plurality of crimped material W may be held at equal intervals, so that the production line may be automated.

By attaching an appropriate label to the information recording substrate CD obtained as described above, a final product is completed.

Fig. 4 shows the pressure measurement film (trade name "Prescale Ultra Low Pressure" manufactured by Fuji Photo Film Co., Ltd.) on a 2.46 mm thick disk-shaped substrate, and a 5 mm thick silicone rubber. The clearance between the two pressure rolls 11 and 12 with a diameter of 130 mm, which is bonded to the press surface, is 2.25 m
This is a pressure measurement film after crimping when set to m and crimped at a line speed of 5 m / min.

As is clear from the figure, uniform coloring appears,
It can be seen that the pressure is uniformly applied to the entire surface of the disk. In addition, no displacement was recognized.

In the above embodiment, the case where a roll press having a pair of pressure rolls is used has been described. However, the present invention is not limited to such a case, and a plurality of pressure rolls may be used as necessary.

In addition, a wedge-shaped clearance adjusting member capable of adjusting the clearance by, for example, entering and retreating is inserted between the two pressure bonding rolls, and both ends of one roll shaft are constantly urged from opposite directions by a fluid pressure, a biasing means such as a spring. By applying the force, the roll press machine may be prevented from being damaged.

Further, when a thermosetting adhesive is used as the adhesive, a heater may be attached to one of the pressure rolls.

〔The invention's effect〕

As described above in detail, according to the method of the present invention using a specific holder when pressing a disc-shaped base material using a roll press machine, a disc-shaped information recording substrate with a small displacement can be reduced even if Even in a space, it can be manufactured at low cost and with good yield.

[Brief description of the drawings]

FIG. 1 is a front view of a roll press used for carrying out the method of the present invention, FIG. 2 is a sectional view of a material to be pressed, FIG. 3 is a perspective view showing an example of a holder used in the method of the present invention, and FIG. Is a plan view of a pressure measurement film showing a pressure distribution applied to a material to be compressed when a roll press is used, FIG. 5 is a front view of a hydraulic press used in a conventional compression method, and FIG. 6 is a hydraulic press. It is a top view of the pressure measurement film which shows the pressure distribution applied to a to-be-compressed material at the time of using. 1 roll press machine (compression bonding means) 11,12 pressure bonding rolls 11a, 12a roll axis CD disk information recording substrate W material to be pressed (disk base material)

Claims (2)

(57) [Claims] 1. A disk-shaped information recording substrate is manufactured by pressing a plurality of disk-shaped substrates stacked one on top of another with an adhesive between the substrates, using a roll press machine having at least a pair of pressure-bonding rolls. In the above, the plurality of disk-shaped substrates, having a through-hole having a diameter slightly larger than the diameter of the plurality of disk-shaped substrates, a body slightly thinner than the plurality of disk-shaped substrates, the through-hole A disc, wherein the disc is stored in a holder having a bottom flexible film for closing the bottom and a top flexible film for opening and closing the top of the through-hole so as to be opened and closed, and then fed to the roll press machine. Manufacturing method of a state information recording substrate. 2. The method for manufacturing a disc-shaped information recording substrate according to claim 1, wherein said pressure roll has an elastic member provided on a peripheral surface thereof.