JP2007109307A - Method and apparatus for bonding disk substrates - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for bonding disk substrates with which the warp angle of the disk substrates can be efficiently adjusted. <P>SOLUTION: The bonding apparatus 10 has such constitution such that two disk substrates d1, d2 bonded via an ultraviolet ray curable resin are irradiated with ultraviolet rays and the ultraviolet ray curable resin is cured, and is provided with an ultraviolet ray source 22 irradiating one side plane of a disk D with ultraviolet rays, and a ultraviolet ray polarizing means 21 provided at the middle of a path where the ultraviolet rays emitted from the ultraviolet ray source 22 travel to the disk substrate d2. In the ultraviolet ray polarizing means 21, difference of illuminance of ultraviolet rays emitted to the disk substrate d2 side is 50% or more. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bonding method and a bonding apparatus for a disk substrate constituting a disk used as an optical information recording medium, and in particular, a bonding method and a bonding apparatus for a disk substrate capable of adjusting a warp angle of an optical disk. About.

  CD-R (Compact Disc-recordable), CD (Compact Disc), DVD (digital versatile disc), DVD-R (digital versatile disc-recordable) are optical discs that record or reproduce information using laser light. Etc. are already popular.

  In the optical disk manufacturing process, for example, a liquid UV curable resin is applied onto a resin disk substrate by spin coating or screen printing, and then irradiated with UV light in a state of being bonded to another disk substrate. Then, the ultraviolet curable resin is cured.

  When performing recording / reproduction, the optical disk rotates the disk and irradiates the surface of the disk with laser light to focus the laser light on a groove of several microns formed on the recording layer of the disk substrate. Based on the aberration of the lens used for focusing the laser beam, a high-density recording disk such as a DVD disk needs to satisfy a warp angle within ± 0.8 °. For this reason, in the optical disc manufacturing process, it is necessary to adjust so that the disc on which the two disc substrates are bonded has a warp angle within ± 0.8 °.

  As a technique for adjusting the warp angle of the disk to bond the disk substrates, for example, the technique disclosed in Patent Document 1 below is known.

JP 2004-30756 A Japanese Patent Laid-Open No. 9-306033

  In Patent Document 1, an ultraviolet light source is provided above and below a support plate on which an optical disk is disposed, and the optical disk is irradiated with ultraviolet light from the ultraviolet light source. A shutter is provided in the middle of the UV irradiation path for irradiating UV light to one side of the disk and the UV irradiation path for irradiating UV light to the other side of the disk, and the UV irradiation start timing is controlled by these shutters. To do.

  Further, although the warp angle of the disk is not adjusted, in Patent Document 2, a mask is provided between the ultraviolet light source and the disk, and the pattern is formed on the disk by irradiating the disk with ultraviolet light through the mask. Or drawing a design.

  Conventionally, the warping angle of the disc after pasting is changed by changing the substrate state before laminating with a molding machine, after the UV curable resin is cured by uniformly irradiating ultraviolet rays to bond the disc substrate. Was adjusting. For this reason, there is a problem that the conditions of the molding machine must be changed every time the bonding conditions are changed. As a result of intensive studies, the present inventor has paid attention to the fact that the disc substrate can be warped by imparting a bias to the amount of ultraviolet irradiation. Then, the inventors have found that by irradiating ultraviolet rays, the ultraviolet curable resin is cured to bond the disk substrates and the warp angle can be adjusted.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a disk substrate bonding method and a bonding apparatus capable of efficiently adjusting the warp angle of the disk substrate.

  The object of the present invention is a disk substrate bonding apparatus for irradiating two disk substrates bonded via an ultraviolet curable resin with ultraviolet rays to cure the ultraviolet curable resin, wherein one surface of the disk substrate is An ultraviolet light source for irradiating the disk with ultraviolet light, and an ultraviolet polarization means provided in the middle of the path to which the ultraviolet light emitted from the ultraviolet light source reaches the disk substrate, the ultraviolet polarization means being emitted toward the disk substrate side. This is achieved by a disk substrate laminating apparatus characterized in that the difference in illuminance of ultraviolet rays is 50% or more.

  The above object of the present invention is a method for laminating a disk substrate by irradiating two disk substrates bonded via an ultraviolet curable resin with ultraviolet rays to cure the ultraviolet curable resin. When the ultraviolet light is polarized by the ultraviolet light polarizing means in the middle of the path of the irradiated ultraviolet light to the disk substrate, the ultraviolet light polarizing means has an illuminance of the ultraviolet light emitted to the disk substrate side. The difference is 50% or more. This is achieved by a method for laminating disk substrates, which is characterized in that the difference is 50% or more.

  The present invention comprises an ultraviolet polarizing means, and when the ultraviolet curable resin is cured by irradiating the ultraviolet curable resin, the amount of the ultraviolet light applied to the disk substrate is controlled by the ultraviolet polarizing means, thereby bonding the disk substrates together. A predetermined warp angle can be given to the disc. For this reason, it is not necessary to perform a step of bending the disk with a molding machine after the disk substrates are bonded together as in the conventional disk manufacturing process, and the manufacturing task can be improved.

  The ultraviolet polarizing means is preferably an optical filter whose transmittance changes in a direction perpendicular to the surface emitting ultraviolet light. In this way, the ultraviolet light irradiated to the disk substrate is polarized by the optical filter, and the difference in illuminance of the ultraviolet light emitted to the disk substrate side is adjusted to be 50% or more. In this way, by controlling the amount of ultraviolet light applied to the disk substrate by the optical filter, a predetermined warp angle can be given to the disk formed by bonding the disk substrates.

  ADVANTAGE OF THE INVENTION According to this invention, the bonding method and bonding apparatus of a disc substrate which can adjust the curvature angle of a disc substrate efficiently can be provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a bonding apparatus according to the present invention. The laminating apparatus 10 of this embodiment is used in the process of manufacturing an optical disk used as an optical recording medium such as a DVD or DVD-R, and is applied to one of the two disk substrates. An optical disk (hereinafter also simply referred to as a disk) is manufactured by bonding both disk substrates together with the ultraviolet curable resin sandwiched between them and curing the ultraviolet curable resin.

  The bonding apparatus 10 includes a turntable 11 having a regular circular shape when viewed from the top (front view of FIG. 1). The turntable 11 is provided with a plurality of support portions 12 on which the disk substrates D of optical disks are placed at equal intervals in the circumferential direction of the upper surface thereof. In the present embodiment, the five support portions 12 are arranged at equal intervals in the circumferential direction of the turntable 11, but the number of support portions 12 is not particularly limited and can be changed as appropriate.

  FIG. 2 is a perspective view for explaining a state in which the disk substrate is placed on the support portion of the turntable. The support portion 12 has a substantially cylindrical shape protruding upward from the upper surface of the turntable 11, and a support surface 12 a on which one disk substrate d <b> 2 is placed is formed at the upper end of the support portion 12. At the center of the support surface 12a, a positioning pin 13 is inserted upward through the center opening of the mounted disk substrate d2 and positions the disk substrate D on the support surface 12a.

  In the present embodiment, the surface on which the ultraviolet curable resin is applied is located on the upper surface side in a state where the disk substrate d2 is placed on the support surface 12a. Then, the disk substrate d1 is bonded to the upper surface of the disk substrate d2 via an ultraviolet curable resin. Thus, the disk D is formed by bonding the disk substrates d1 and d2.

  Since the turntable 11 can change the circumferential position of the support portion 12 by rotating as shown by an arrow in FIG. 1, the turntable 11 is attached to a processing apparatus separately provided outside the turntable 11 in the radial direction. The support unit 12 can be moved to a corresponding position and a predetermined process can be performed on the disk substrates d1 and d2 placed on the support unit 12. In the present embodiment, the turntable 11 functions as a conveying member.

  On the outer side in the radial direction of the turntable 11, as each processing apparatus for manufacturing an optical disk, a carry-in unit 14, a bonding unit 16, and ultraviolet irradiation in turn in the counterclockwise direction of FIG. An ultraviolet irradiation unit 18 that functions as a unit and an unloading unit 19 are provided.

  The carry-in unit 14 has a configuration in which a disk substrate d2 that has been previously coated with an ultraviolet curable resin on one side is placed on the support unit 12 of the turntable 11 by a robot arm (not shown). The disk substrate d2 is placed in a state where the surface on which the ultraviolet curable resin is applied faces upward (the side opposite to the support surface 12a of the support portion 12).

  The bonding unit 16 has a mechanism for bonding the other disk substrate d1 to one disk substrate d2 placed on the support surface 12a in a chamber maintained in a vacuum state. As a mechanism of the bonding unit 16, a conventional configuration can be used.

  The ultraviolet irradiation unit 18 irradiates the pair of disk substrates d1 and d2 bonded by the bonding unit 16 with ultraviolet rays from below the turntable 11, and cures the ultraviolet curable resin to thereby bond the disk substrates d1 and d2 together. Adhere to a single disc. A specific mechanism of the ultraviolet irradiation unit 18 will be described later.

  The unloading part 19 takes out the disk D stuck together from each support part 12 of the turntable 11 in order by a robot arm (not shown) after irradiation of ultraviolet rays, and conveys the disk D to another transport mechanism or a storage part (not shown). .

  FIG. 3 is a diagram illustrating a configuration of the ultraviolet irradiation unit. As shown in FIG. 3, the ultraviolet irradiation unit 18 has a lower surface of the disk D composed of the disk substrates d1 and d2 supported by the support unit 12 of the turntable 11 (that is, the lower disk substrate d2 in this embodiment). The ultraviolet light source 22 which irradiates ultraviolet rays is provided on the lower surface. The ultraviolet light source 22 is configured to irradiate parallel light L0 including ultraviolet rays upward.

  The site | part in which the support part 12 of the turntable 11 is provided, and the support part 12 are comprised from the material which can permeate | transmit an ultraviolet-ray at least, for example, is glass.

  The ultraviolet irradiating unit 18 is provided with an ultraviolet polarizing means 21 in the middle of a path where the ultraviolet rays emitted from the ultraviolet light source 22 reach the disk substrate d2. In the present embodiment, an optical filter is used as the ultraviolet polarization means 21. The ultraviolet irradiation unit 18 can be configured to replace the ultraviolet polarization means 21.

  The ultraviolet polarization means 21 converts the parallel light L0 incident from the ultraviolet light source 22 into polarized light L1 obtained by adjusting so as to have a predetermined illuminance difference, and irradiates the polarized light L1 below the support portion 12 in the turntable 11. The ultraviolet polarization means 21 is configured such that the difference in illuminance of ultraviolet rays emitted to the disk substrate d2 side is 50% or more.

  FIG. 4 is a diagram showing a state in which the optical filter which is the ultraviolet polarization unit of the present embodiment is viewed in the ultraviolet incident direction. FIG. 5 is a graph showing the relationship between the transmittance of ultraviolet rays and the position in the X direction in the optical filter of FIG.

  The optical filter functioning as the ultraviolet polarization means of the present embodiment has a plane perpendicular to the direction in which the ultraviolet light is incident, and its transmittance changes in a predetermined linear direction (X direction in FIG. 4) on the plane. It is configured as follows. That is, the optical filter of the present embodiment has a different ratio of transmitting the light incident from the ultraviolet light source 22 depending on its position. Therefore, the polarized light emitted from the optical filter has an illuminance P2 at the portion x2 where the transmittance is high. And the illuminance P1 decreases in the portions x1 and x3 where the transmittance is small. As described above, the transmittance of the ultraviolet polarizing means 21 of the present embodiment is adjusted by the material of the optical filter so that the difference in illuminance (P2−P1) of the ultraviolet rays emitted to the disk substrate d2 side is 50% or more. It is configured.

  When an optical filter is used as the ultraviolet polarizing means 21 as in the present embodiment, the transmittance is changed in the direction perpendicular to the surface from which the ultraviolet light is emitted (plane direction), and the disk substrate d2 side is changed. If the difference in illuminance of the emitted ultraviolet rays is within a range of 50% or more, the transmittance distribution can be arbitrarily set.

  FIG. 6 is a diagram illustrating another form of the optical filter of the present embodiment. FIG. 7 is a diagram illustrating another form of the optical filter. 6 and 7 are optical filters in a state where a plane perpendicular to the direction in which light having ultraviolet rays is transmitted is viewed in plan. In the optical filters of FIGS. 6 and 7, a portion where the transmittance of ultraviolet rays is large is indicated by a dark tone, and a portion where the transmittance is low is indicated by a thin tone.

  As shown in FIG. 6, the optical filter can be configured such that the transmittance gradually increases (or decreases) in a predetermined linear direction. Further, as shown in FIG. 7, the optical filter can be configured such that the transmittance decreases (or increases) toward the center. The pattern of the transmittance distribution in the optical filter is not limited to these, and can be appropriately modified as long as the difference in illuminance of the emitted ultraviolet light can be 50% or more.

  As such an optical filter, a liquid crystal panel having a predetermined transmittance pattern can be used. In this case, a predetermined transmittance can be obtained by measuring in advance the transmittance distribution that provides the desired warping angle of the disk to be manufactured and adjusting the orientation of the liquid crystal molecules on the panel based on the measured transmittance distribution. A liquid crystal panel having the following pattern can be obtained.

  The laminating apparatus 10 according to the present invention includes an ultraviolet polarization unit 21 and controls the irradiation amount of the ultraviolet ray irradiated to the disk substrate d2 by the ultraviolet polarization unit 21 when the ultraviolet curable resin is cured by irradiating the ultraviolet ray. Thus, a predetermined warp angle can be given to the disk D formed by bonding the disk substrate d1. For this reason, it is not necessary to perform a step of bending the disk with a molding machine after the disk substrates are bonded together as in the conventional disk manufacturing process, and the manufacturing task can be improved.

Next, examples of the present invention will be described.
Using the laminating apparatus of the above embodiment, as Examples 1 and 2 and Comparative Example 2, the optical curing resin is controlled by an optical filter having a predetermined transmittance distribution, and the ultraviolet curable resin is cured, and a disk is formed with a warp angle. After manufacturing, eight discs manufactured under the same conditions were rotated under the same conditions, and the amount of surface runout was measured. In Comparative Example 1, a conventional laminating apparatus was used to irradiate parallel light including ultraviolet rays from an ultraviolet light source to cure the ultraviolet curable resin, to manufacture a disk, and then the disk 8 manufactured under the same conditions. The amount of runout was measured by rotating the sheet under the same conditions. In each of Comparative Examples 1 and 2 and Examples 1 and 2, the surface runout amount at a position where the radius R of the disk was 58 mm was measured. The conditions of the optical filters used in Examples 1 and 2 and Comparative Examples 1 and 2 are shown in the following table.

  The results of Comparative Examples 1 and 2 are shown in FIGS. 8 and 9, respectively, and the results of Examples 1 and 2 are shown in FIGS. 10 and 11, respectively. 8 to 11 are graphs showing the relationship of the surface runout amount (mm) with respect to the measurement position (°) of the disk when the disk is rotated.

  As shown in FIG. 8, in Comparative Example 1, it was found that the surface runout amount with respect to the measurement position of the disk was not constant between the disks, and there was no periodicity. Further, as shown in FIG. 9, in Comparative Example 2, it was found that the surface runout amount with respect to the measurement position of the disk has no periodicity as in Comparative Example 1.

  As shown in FIG. 10, in Example 1, it was found that the surface runout amount changed in two cycles for one rotation of the disk. Further, as shown in FIG. 11, in Example 2, it was found that the surface runout amount changed more significantly in two cycles per rotation of the disk than in Example 1. Here, it can be said that stable recording and reproduction can be performed by showing a stable period with respect to one rotation of the disk. Thus, when curing the ultraviolet curable resin, it can be seen that by making the disc a warp angle with a transmittance difference of 65% or more, the amount of surface deflection becomes a constant period and stable recording and reproduction can be performed. It was.

It is a figure which shows the optical disk bonding apparatus which concerns on this invention. It is a perspective view explaining the state which mounts a disc board | substrate in the support part of a turntable. It is a figure which shows the structure of an ultraviolet irradiation part. It is a figure which shows the state which looked at the optical filter which is an ultraviolet-polarization means of this embodiment in the incident direction of an ultraviolet-ray. 5 is a graph showing the relationship of the transmittance of ultraviolet rays with respect to the position in the X direction in the optical filter of FIG. 4. It is a figure explaining the other form of an optical filter. It is a figure explaining the other form of an optical filter. 6 is a graph showing the results of Comparative Example 1. 10 is a graph showing the results of Comparative Example 2. 3 is a graph showing the results of Example 1. 10 is a graph showing the results of Example 2.

Explanation of symbols

10 Bonding device 11 Turntable (conveying member)
12 Supporting part 16 Bonding part 18 Ultraviolet irradiation part 21 Ultraviolet polarization means 22 Ultraviolet light source d1, d2 Disk substrate D Disk

Claims (4)

A disk substrate bonding apparatus for irradiating two disk substrates bonded via an ultraviolet curable resin with ultraviolet rays to cure the ultraviolet curable resin,
An ultraviolet light source that irradiates one surface of the disk substrate with ultraviolet light;
UV polarization means provided in the middle of the path where the ultraviolet light emitted from the ultraviolet light source reaches the disk substrate,
The disk substrate bonding apparatus, wherein the ultraviolet polarization means has a difference in illuminance of ultraviolet light emitted to the disk substrate side of 50% or more.   2. The disk substrate bonding apparatus according to claim 1, wherein the ultraviolet polarization means is an optical filter whose transmittance changes in a direction perpendicular to a surface emitting ultraviolet light. A method of laminating a disk substrate by irradiating two disk substrates bonded via an ultraviolet curable resin with ultraviolet rays to cure the ultraviolet curable resin,
Irradiate one side of the disk substrate with ultraviolet light,
When the irradiated ultraviolet rays are polarized by the ultraviolet polarization means in the middle of the path to the disk substrate, the ultraviolet polarization means has a difference in illuminance of the ultraviolet rays emitted to the disk substrate side of 50% or more. A method of laminating a disk substrate characterized by   4. The disk substrate bonding method according to claim 3, wherein the ultraviolet polarizing means is an optical filter whose transmittance changes in a direction perpendicular to a surface emitting ultraviolet light.

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