JP2000311391A - Production of resin disk substrate and apparatus for producing resin disk substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To melt and process the flashes generated at the peripheral edge of a resin disk substrate with high accuracy by setting the irradiate direction of a laser beam perpendicularly to the main surface part of a resin disk substrate and irradiating the flashes with this laser beam, thereby melting the flashes. SOLUTION: The resin disk substrate 1 molded by injection molding is installed on a disk table 2 and the disk table 2 is rationally manipulated at a specified rotating speed by a spindle 3. The resin disk substrate 1 is positioned relative to the disk table 2 and the spindle 3 by using a positioning pin 4b at this time and simultaneously the inner peripheral flash falling to the inner side is directed and corrected toward the outer side by utilizing the tapered part on the bottom end side of the positioning pin 4b and thereafter, the data surface 1d is irradiated perpendicularly thereto to execute the melting and processing, by which the dislodgment of the inner peripheral flash 1b may be prevented without diminishing the bore of a central hole 1C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin disk substrate manufacturing method and a resin disk substrate manufacturing apparatus for melting burrs on an inner peripheral portion or an outer peripheral portion of a resin disk substrate.

[0002]

2. Description of the Related Art Various types of disk-shaped recording media such as optical disks and magneto-optical disks have been proposed.
These disc-shaped recording media are formed by forming a signal recording layer on a resin disc substrate. As shown in FIG. 1, this resin disk substrate is formed in a disk shape by injection molding using a transparent synthetic resin such as polycarbonate (polycarbonate) as a material. This resin disk substrate 1 has a center hole 1c that serves as a positioning reference when chucking in a recording / reproducing apparatus or the like.

In the resin disk substrate 1, after the injection molding is performed, as shown in FIG. 2, an outer peripheral portion and an inner peripheral portion have a size or a size generated due to a feature in a mold structure. There are an outer flash 1a and an inner flash 1b whose shapes are unstable. The outer peripheral burr 1 a is formed along the outer peripheral edge of the resin disk substrate 1.
Exists on both the front side and the back side. Inner circumference burr 1b
Exists along the inner peripheral edge of the resin disk substrate 1 and only on one surface side of the resin disk substrate 1 or on the rear surface side. Since these burrs are fragile and easily chipped, they fall off during transportation of the disk substrate and the like, causing a quality problem.

In order to solve this problem, the present inventor has
As shown in FIG. 4, in the state in which the resin disc substrate 1 on the disc table 2, using a CO ₂ laser,
A method for removing the outer peripheral burr 1a and the inner peripheral burr 1b by irradiating a laser beam and fusing it was developed. That is, first, the resin disk substrate 1 is set on the disk table 2. The disk table 2 is rotated by a spindle 3 at a constant rotation speed. The disk table 2 has positioning pins 4a (not shown) for positioning the resin disk substrate 1 from the inside of the disk table 2 so that the resin disk substrate 1 does not become eccentric even when rotated by the spindle 3. It has a vacuum mechanism for dust suction. On the upper side of the disk table 2,
A positioning pin 4b for positioning the resin disk substrate 1 from above is provided.

Then, a CO ₂ laser capable of irradiating the outer peripheral burr 1a and the inner burr 1b with laser light under a certain condition is used. The irradiation position of the laser light of the CO ₂ laser is adapted to be positioned with high accuracy. By the irradiation of the laser beam, the burrs are melted and are prevented from dropping from the resin disk substrate 1.

[0006]

In the above-described apparatus for manufacturing a resin disk substrate, as shown in FIG. 4, the data surface 1d line of the resin disk substrate 1 is used as a reference surface, and the data surface 1d line is used. Is irradiated with a CO ₂ laser from an oblique direction indicated by an arrow 5a. In this case, swelling due to the melting of the resin occurs at the laser beam irradiation portion. The height of the swell is preferably as small as possible with respect to the reference plane 1d. In addition, the melting range in the radial direction from the outer peripheral portion of the resin disk substrate 1 to the data surface also needs to be reduced as much as possible due to the demand for increasing the recording capacity.

However, the height and the range of the bulge caused by the melting of burrs tend to increase as the resin disk substrate is melted by the laser. In the above method, in order to provide a resin disk having a small swelling and melting range due to melting, adjustment of the output of laser light per unit time and adjustment of the irradiation position of laser light and the like are dealt with. With some measures, the swelling and the melting range cannot be sufficiently reduced.

Accordingly, the present invention has been proposed in view of the above-mentioned circumstances, and a method for preventing burrs on a peripheral portion of a resin disk substrate from falling off by melting by irradiating a laser beam is provided. An object of the present invention is to provide a resin disk substrate manufacturing method and a resin disk substrate manufacturing apparatus capable of reducing the height of the bulge of the peripheral portion and its range of influence on the recording surface.

[0009]

In order to solve the above-mentioned problems, a method of manufacturing a resin disk substrate according to the present invention is directed to a method of manufacturing a resin disk substrate by injection of laser light onto burrs generated on a peripheral portion of a resin disk substrate formed by injection molding. A method for manufacturing a resin disk substrate in which the burrs are irradiated and melted to prevent the burrs from dropping from the resin disk substrate, wherein the irradiation direction of the laser beam is perpendicular to the main surface of the resin disk substrate. It is assumed that.

Further, the method of manufacturing a resin disk substrate according to the present invention is directed to a method of manufacturing a resin disk substrate by irradiating a laser beam to a burr generated at a peripheral portion of a resin disk substrate formed by injection molding to melt the resin disk. In the method of manufacturing a resin disk substrate for preventing the resin disk from falling off, the laser beam irradiated to the burrs is transmitted through the resin disk substrate and absorbed.

The apparatus for manufacturing a resin disk substrate according to the present invention irradiates laser light to burrs generated on the peripheral portion of the resin disk substrate formed by injection molding to melt the burrs. An apparatus for manufacturing a resin disk substrate which prevents the resin disk substrate from falling off, comprising light irradiation means for vertically irradiating a main surface portion of the resin disk substrate with a laser beam.

Further, the resin disk substrate manufacturing apparatus according to the present invention is characterized in that burrs generated on a peripheral portion of a resin disk substrate formed by injection molding are irradiated with a laser beam to melt the resin disk. An apparatus for manufacturing a resin disk substrate that prevents the burrs from falling off from the substrate, comprising: a laser beam irradiating unit that irradiates a laser beam. The laser beam after irradiation is transmitted through a resin disk substrate and absorbed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the resin disk substrate manufacturing method according to the present invention is a method for manufacturing a resin disk substrate constituting various types of disk-shaped recording media such as an optical disk and a magneto-optical disk. The resin disk substrate manufacturing apparatus according to the present invention is an apparatus capable of performing the resin disk substrate manufacturing method according to the present invention.

The disc-shaped recording medium is formed by forming a signal recording layer on a resin disc substrate 1. This resin disc substrate is made of polycarbonate (Polycarbonate).
First, a disk is formed by injection molding using a transparent synthetic resin or an amorphous polyolefin resin as shown in e). This resin disk substrate 1 has a center hole 1c that serves as a positioning reference when chucking in a recording / reproducing apparatus or the like. After the injection molding is performed, the resin disk substrate 1 has, as shown in FIG. 2, an outer peripheral edge portion and an inner peripheral edge portion with features in a mold structure and a characteristic at the time of separation from the mold. The outer burrs 1a and the inner burrs 1b are unstable in size and shape due to the combination of shearing scraps caused by punching. Since the burrs 1a and 1b are fragile and easily chipped, they fall off during transport of the disk or the like, causing a quality problem.

The outer peripheral burrs 1 a are present on both the front side and the back side of the resin disk substrate 1 along the outer periphery of the resin disk substrate 1. As shown in FIG. 3, the inner peripheral burr 1 b exists along the inner peripheral edge of the resin disk substrate 1 on only one surface side of the resin disk substrate 1 or only one side on the rear surface side.

As shown in FIG. 4, the resin disk substrate manufacturing apparatus according to the present invention includes a spindle unit 6 for positioning and stably rotating the resin disk substrate 1. In this resin disk substrate manufacturing apparatus,
The resin disk substrate 1 is subjected to burr melting by laser light irradiation while being held by the spindle unit 6.

In this resin disk substrate manufacturing apparatus, first, as shown in FIG. 4, a resin disk substrate 1 formed by injection molding is set on a disk table 2. The disk table 2 is rotated by a spindle 3 at a constant rotation speed. Disk table 2
In order to prevent the resin disk substrate 1 from being eccentric when the resin disk substrate 1 is rotated, positioning pins 4a (not shown) for positioning the resin disk substrate 1 from inside the disk table 2 and dust suction are provided. It has a vacuum mechanism. Also, disk table 2
A positioning pin 4b for positioning the resin disk substrate 1 from above is provided on the upper side.

As shown in FIG. 4, the resin disk substrate manufacturing apparatus can irradiate the outer peripheral burr 1a and the inner peripheral burr 1b of the resin disk substrate 1 with a laser beam under certain conditions. That is, this resin disk substrate manufacturing apparatus includes a laser oscillator (CO ₂ laser), and the laser beams 5a, 5b, 5c
Has been made to get. These laser beams 5a, 5
b and 5c are designed so that the irradiation position can be positioned with high accuracy.

Here, as shown in FIG. 4, an experiment in which laser beams 5a, 5b and 5c are applied to the inner peripheral burr 1b from three directions with reference to the data surface 1d line which is the main surface of the resin disk substrate 1. Was done. Laser spot diameter about 1m
m, the laser power (intensity) was 4.8 W, the rotation speed of the resin disk substrate 1 was 20 rpm, and the conditions other than these irradiation directions were all the same.
Direction (incident angle 45 ° direction and -45 °
In the case of laser beams 5a and 5c emitted from
When the irradiation amount of the laser beam to the inner peripheral burr 1b is small,
The inner peripheral burr 1b is more likely to fall into the inner peripheral side, and as a result, the inner diameter of the center hole 1c is smaller. Further, when the irradiation amount of the laser beam is large, the base material other than the burrs is melted, and the inner diameter of the center hole 1c is reduced.

On the other hand, a laser beam 5b irradiated from a direction perpendicular to the data surface 1d (incident angle 0 ° direction).
In this case, the inner peripheral burr 1b does not fall down to the inner peripheral side, the size of the inner peripheral burr 1b can be reduced, and the inner peripheral burr 1b can be prevented from falling off by being fused to the base material. The small inner peripheral burr 1b has disappeared.

By the way, as shown in FIG. 5, the inner peripheral burr 1b may have originally fallen inward.
The inner peripheral burr 1b which has fallen into such an inside
Irradiates the laser beam 5b perpendicularly to the data surface 1d,
As a result, the inner diameter of the center hole 1c is reduced. To solve this problem, as shown in FIG. 6, the resin disk substrate 1 is positioned with respect to the disk table 2 and the spindle 3 using the positioning pins 4b shown in FIG. The peripheral burr 1b is straightened outward using the tapered portion on the lower end side of the positioning pin 4b, and then, as shown in FIG. 7, the laser beam 5b is irradiated perpendicularly to the data surface 1d to perform a melting process. As a result, as shown in FIG.
Of the inner peripheral burr 1b can be prevented without reducing the inner diameter of the inner burr.

As shown in FIG. 9, the outer burr 1a is irradiated with the laser beam 5a by directly aiming at the outer burr 1a obliquely above the data surface 1d of the resin disk substrate 1. As shown in FIG. 10, a laser beam 5c is directed to the outer peripheral burr 1a obliquely from the lower side of the data surface 1d of the resin disk substrate 1 and irradiates the laser beam 5c directly from the outer surface 1e of the resin disk substrate 1. The comparison was made between the case where the laser beam 5c is irradiated through the resin disk substrate 1 so as to be absorbed through the surface 1d. In addition,
According to the properties of the CO ₂ laser, the resin disk substrate 1 can be melted because the laser light is absorbed by the resin disk substrate 1. That is, the laser light of the CO ₂ laser is absorbed by transmitting through the resin disk substrate 1.

The following Table 1 shows the data surface 1 for the upper peripheral burr 1a when the laser light conditions are the same.
When the laser beam 5a is irradiated obliquely from above d,
This is a comparison of the case where the upper outer peripheral burr 1a is irradiated with the laser beam 5c obliquely from the lower side of the data surface 1d. The outer peripheral burr 1a before laser beam irradiation has a length (width)
Was about 40 μm and the thickness was about 20 μm.

[0025]

[Table 1]

In this Table 1, the “effective range of melting in the laser spot” is an evaluation indicating the range of variation of the resin disk substrate 1 within a predetermined height of the swelling with respect to the position of the laser spot in the stationary state. This is an item and is a parameter indicating a range that can respond to a change in the shape of the resin disk substrate. The larger the "effective range of melting in the laser spot", the better the value. The “heat affected range from the outer peripheral edge” is an evaluation item indicating a range in the radial direction on the inner peripheral side from the outer peripheral edge, which has swelled under the influence of laser light irradiation. The smaller the “heat affected range from the outer peripheral edge”, the better.

As can be seen from Table 1, when the upper outer peripheral burr 1a is irradiated with the laser beam 5c obliquely from the lower side of the data surface 1d, the upper outer peripheral burr 1a is inclined obliquely from the upper side of the data surface 1d. As compared with the case of irradiating the laser beam 5a to the laser beam, the effective range of the melting process in the laser spot is expanded 12 times, and the heat affected range from the outer peripheral edge is
It is reduced to 2/5.

As shown in FIG. 9, even when the lower outer burr 1a is irradiated with the laser beam 5b obliquely from the upper side of the data surface 1d, the upper outer burr 1a is lower than the data surface 1d. The same result as in the case of irradiating the laser beam 5c more obliquely is obtained.

[0029]

As described above, in the resin disk substrate manufacturing method and the resin disk substrate manufacturing apparatus according to the present invention, the irradiation direction of the laser beam is set to be perpendicular to the main surface of the resin disk substrate. A burr generated on the periphery of the resin disk substrate formed by molding is irradiated with a laser beam and melted to prevent the burr from falling off the resin disk substrate.

Therefore, the present invention enables high-precision burr melting processing, and particularly when applied to inner peripheral burr,
Enables burr melting without changing the inner diameter of the center hole.

In the resin disk substrate manufacturing method and the resin disk substrate manufacturing apparatus according to the present invention, the laser beam irradiated to the burr is transmitted through the resin disk substrate and absorbed.

Accordingly, the present invention can provide a resin disk substrate manufacturing method and a resin disk substrate manufacturing apparatus capable of reducing the height of the bulge of the peripheral portion with respect to the recording surface and the range of influence on the recording surface. Things.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a resin disk substrate manufactured by a resin disk substrate manufacturing method according to the present invention.

FIG. 2 is a longitudinal sectional view showing a configuration of the resin disk substrate.

FIG. 3 is a longitudinal sectional view showing a configuration of a main part of the resin disk substrate.

FIG. 4 is a longitudinal sectional view showing a configuration of a main part of a resin disk substrate manufacturing apparatus according to the present invention.

FIG. 5 is a longitudinal sectional view showing a configuration of a main part of the resin disk substrate before being processed in the resin disk substrate manufacturing apparatus.

FIG. 6 is a longitudinal sectional view showing a configuration of a main part of a resin disk substrate that has been preprocessed by the resin disk substrate manufacturing apparatus.

FIG. 7 is a longitudinal sectional view showing a configuration of a main part of a resin disk substrate that has been melted in the resin disk substrate manufacturing apparatus.

FIG. 8 is a longitudinal sectional view showing a configuration of a main part of a resin disk substrate processed by the resin disk substrate manufacturing apparatus.

FIG. 9 is a longitudinal sectional view showing an irradiation direction of a laser beam applied to a lower peripheral burr in the resin disk substrate manufacturing apparatus.

FIG. 10 is a longitudinal sectional view showing an irradiation direction of a laser beam applied to an upper peripheral flash in the resin disk substrate manufacturing apparatus.

[Explanation of symbols]

1. Resin disk substrate, 1a outer burr, 1b inner burr, 2 disk table, 3 spindle

Claims (6)

[Claims] 1. A resin disk substrate for preventing burrs from falling off from the resin disk substrate by irradiating laser light to burrs generated on a peripheral portion of the resin disk substrate formed by injection molding to prevent the burrs from falling off from the resin disk substrate. A method of manufacturing a resin disk substrate, wherein the irradiation direction of the laser beam is perpendicular to a main surface of the resin disk substrate. 2. The method for manufacturing a resin disk substrate according to claim 1, wherein the projection direction of the burr is corrected before the laser beam irradiation. 3. A resin disk substrate for irradiating laser light to burrs formed on the peripheral portion of a resin disk substrate formed by injection molding and melting the burrs to prevent the burrs from falling off from the resin disk substrate. A method of manufacturing a resin disk substrate, wherein the laser beam after being applied to the burr is transmitted through and absorbed by the resin disk substrate. 4. A resin disk substrate for irradiating a laser beam to burrs generated on a peripheral portion of a resin disk substrate formed by injection molding and melting the burrs to prevent the burrs from falling off from the resin disk substrate. A manufacturing apparatus, comprising: a laser beam irradiating unit for irradiating the laser beam, wherein the laser beam irradiating unit irradiates a laser beam perpendicularly to a main surface portion of the resin disk substrate. Equipment for manufacturing disk substrates. 5. The apparatus for manufacturing a resin disk substrate according to claim 4, further comprising a burr correcting means for correcting a burr projection direction prior to the laser light irradiation by the laser light irradiation means. 6. A resin disk substrate for preventing burrs from falling off the resin disk substrate by irradiating laser light to burrs generated on the peripheral portion of the resin disk substrate formed by injection molding to prevent the burrs from falling off the resin disk substrate. A manufacturing apparatus, comprising: a laser beam irradiating unit for irradiating the laser beam, wherein the laser beam irradiating unit irradiates a laser beam to a burr and emits a laser beam irradiated to the burr to a resin An apparatus for manufacturing a resin disk substrate, which transmits and absorbs the inside of the substrate.