JP2006048828A - Disk bonding method and optical disk manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk bonding method and an optical disk manufacturing device capable of suppressing disk deformation caused at the time of disk bonding. <P>SOLUTION: In this disk bonding method for bonding two disk substrates D1 and D2 with an ultraviolet curable adhesive 12, a spot light source 14 capable of emitting ultraviolet rays in spot shapes is used in a curing process step of the adhesive 12, and the curing timing of the adhesive 12 is made different between a disk inner circumference and a disk outer circumference by moving the spot light source 14 from the disk inner circumferential side to the disk outer circumferential side while rotating the disk substrates D1 and D2 on a spindle stage 11. This bonding suppresses the disk deformation caused by the curing and contraction of the adhesive 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a disk laminating method for laminating two disks via an ultraviolet curable adhesive, and an optical disk manufacturing apparatus suitable for use in the manufacture of a bonded type optical disk. The present invention relates to a disc bonding method and an optical disc manufacturing apparatus capable of suppressing deformation of a disc due to curing shrinkage.

  For example, an optical disc such as a DVD (Digital Versatile Disc) has a structure in which two transparent synthetic resin discs having a diameter of 120 mm and a thickness of 0.6 mm are bonded together via an ultraviolet curable adhesive. . Conventionally, this bonded optical disc has been manufactured through the processes schematically shown in FIGS.

  As shown in FIG. 4A, after placing one disk substrate D1 on a spindle stage 1 having a rotational drive source, an ultraviolet curable adhesive 2 is annularly formed on the inner periphery of the upper surface of the disk substrate D1. Supply. Then, as shown in FIG. 4B, the other disk substrate D2 is superposed on the disk substrate D1 with the adhesive 2 interposed therebetween. On the rotation axis 1a of the spindle stage 1, a reference pin 1b that fits in the center hole C of the disk substrates D1 and D2 is provided upright. The two disk substrates D1 and D2 are connected to the reference pin 1b. Overlaid on the spindle stage 1 with reference to the fitting position of the center hole C with high accuracy.

  Next, as shown in FIG. 4C, the spindle stage 1 is driven, and the two disk substrates D1 and D2 are rotated at high speed around the rotation axis 1a while being uncured between the disk substrates D1 and D2. The adhesive 2 is spread to the outer periphery of the disk by centrifugal force, and the adhesive 2 is spread on the entire surface of the disk. At this time, the surplus of the adhesive 2 is shaken off to the outer side of the disk diameter.

  Finally, after transferring the bonded disk substrates D1 and D2 to the stage 4 for the ultraviolet irradiation process, the entire surface of the disk is irradiated with ultraviolet rays UV from the light source 3 arranged above the center of the disk substrate D2. The adhesive 2 is cured (FIG. 4D). As described above, the bonding process of the optical disc D is completed.

  Prior art documents related to the invention of this application are shown below.

JP 2000-260072 A JP 2002-298454 A

  As described above, when the bonded optical disk D is manufactured, an ultraviolet UV irradiation process is provided on the disk for the curing process of the adhesive 2 that joins the two disk substrates D1 and D2. . In the conventional disk laminating method, the disk on the spindle stage 1 is irradiated with ultraviolet rays UV from the fixed light source 3 to the entire surface of the disk, and the adhesive 2 interposed between the disk substrates D1 and D2 is simultaneously applied to the entire surface. It is made to harden.

  However, in this method, the deformation of the optical disc D due to the curing shrinkage of the adhesive 2 is increased, and as a result, the track readability by the optical pickup is deteriorated in the optical disc recording / reproducing apparatus. In some cases, the signal writing characteristics are adversely affected.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a disk bonding method and an optical disk manufacturing apparatus that can suppress deformation of a disk that occurs during disk bonding.

  In solving the above problems, the disk laminating method of the present invention is rotated on a holding member using a light source capable of irradiating ultraviolet rays in a spot shape in a curing process of an ultraviolet curable adhesive for laminating two disks. The timing of irradiating the adhesive with ultraviolet rays is made different between the inner peripheral side and the outer peripheral side of the disc.

  According to this method, since the curing timing of the adhesive can be made different between the inner and outer peripheral sides of the disc, the adhesive is cured as compared with the case where the adhesive is simultaneously cured on the entire surface of the disc. It is possible to suppress the deformation of the disk due to the shrinkage.

  As a specific method for differentiating the curing timing of the adhesive between the inner peripheral side and the outer peripheral side of the disc, the light source is moved from the inner peripheral side to the outer peripheral side of the disc while the disc is rotated. The method is preferred. As a result, the adhesive is cured sequentially from the adhesive on the inner peripheral side of the disc, and the volume decrease of the inner peripheral side adhesive due to curing shrinkage is applied by the outer peripheral side adhesive that is quantitatively increased. The overall deformation amount can be greatly suppressed.

  As an apparatus configuration for carrying out the method of the present invention, an optical disk manufacturing apparatus of the present invention includes a holding member that rotatably holds a disk, a supply unit that supplies an ultraviolet curable adhesive, and irradiates ultraviolet rays in a spot shape. A light source and irradiation means for changing the irradiation timing of ultraviolet rays between the inner peripheral side and the outer peripheral side of the disk are provided.

  In particular, the irradiating means includes a moving mechanism that moves the spot light source between the inner peripheral side and the outer peripheral side of the disk.

  According to the disk laminating method of the present invention, a light source capable of irradiating ultraviolet rays in a spot shape is used, and the irradiation timing of ultraviolet rays is made different between the inner peripheral portion and the outer peripheral portion of the rotating disc. Thus, it is possible to provide a time difference in the curing timing of the adhesive between the inner peripheral side and the outer peripheral side of the disk, thereby suppressing the deformation of the disk due to the curing shrinkage.

  Further, according to the optical disk manufacturing apparatus of the present invention, it is possible to bond the disks with high accuracy while suppressing the deformation of the disks, and therefore it is possible to manufacture an optical disk with excellent mechanical characteristics that does not affect the signal characteristics. it can.

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

[First Embodiment]
FIG. 1 shows a schematic configuration of an optical disc manufacturing apparatus 10 according to the first embodiment of the present invention. This optical disk manufacturing apparatus 10 is used for manufacturing an optical disk such as a DVD, and is configured as a disk bonding apparatus that bonds two disk substrates D1 and D2 via an ultraviolet curable adhesive.

  The disc substrates D1 and D2 are made of a transparent material such as polycarbonate, and at least one of them is provided with a recording layer (signal forming surface), and the recording layer forming surface side is a bonding surface. .

  The optical disk manufacturing apparatus 10 includes a spindle stage 11, a discharge nozzle 13 that discharges an ultraviolet curable adhesive 12, a spot light source 14 that irradiates ultraviolet rays in a spot shape, a discharge nozzle 13, and a spot light source 14. The moving mechanism 15 that moves between the position immediately above and the radially outward position, and these control units 16 to 19 are configured.

  The spindle stage 11 corresponds to the “holding member” of the present invention, and is configured to be rotatable around the rotation axis 11a in a state where the disk substrates D1 and D2 are placed. A plurality of suction holes for vacuum-sucking the lower surface of the disk substrate D1 are formed on the upper surface of the spindle disk 11 even if not shown. At the position of the rotation axis 11a on the upper surface of the spindle stage 11, a reference pin 11b that fits into the center hole C of the disk substrates D1 and D2 is provided upright. The rotation control unit 16 drives the spindle stage 11 and controls the number of rotations thereof.

  The discharge nozzle 13 is for supplying the adhesive 12 to a predetermined position on the inner peripheral side of the upper surface of the disk substrate D1, and corresponds to the “supply section” of the present invention. The nozzle port 13a of the discharge nozzle 13 is configured to be movable up and down a predetermined distance with respect to the disk substrate D1, and takes a lowered position when the adhesive 12 is discharged, and a raised position when irradiated with ultraviolet rays from a spot light source 14 described later. It has come to take. The discharge controller 17 controls the discharge operation (ON / OFF) of the adhesive 12, the discharge amount, the discharge timing, and the like.

  The spot light source 14 irradiates ultraviolet rays UV in a wavelength band (for example, 400 nm or less) necessary for curing the adhesive 12 in a spot shape. Although the spot diameter is not particularly limited, in the present embodiment, a light source having a diameter of about 10 mm is used in the defocused state. For the adhesive 12, for example, a rapid-acting radical adhesive is used. The UV control unit 18 controls ultraviolet irradiation timing, illuminance (power), and the like.

  The moving mechanism 15 constitutes the “irradiating means” of the present invention, and includes an arm 20 that supports the discharge nozzle 13 and the spot light source 14, and a linear drive source 21 such as an electric actuator that reciprocates the arm 20 in the disk radial direction. And. The movement control unit 19 performs movement control, movement speed control, movement position (disk radial position) detection, and the like of the arm 20 by the drive source 21.

  The rotation controller 16, the discharge controller 17, the UV controller 18, and the movement controller 19 are each connected to the controller 22. The controller 22 centrally manages the control units 16 to 19, and performs overall control of the bonding process of the disk substrates D1 and D2, as will be described later.

  In the optical disc manufacturing apparatus 10 according to the present embodiment configured as described above, first, basic operations of respective units will be described. FIG. 2 is a process cross-sectional view illustrating a disk bonding process performed by the optical disk manufacturing apparatus 10.

  As shown in FIG. 2A, after placing and adsorbing one disk substrate D1 on the spindle stage 11, an ultraviolet curable adhesive 12 is annularly applied to the upper surface of the disk substrate D1. In the step of applying the adhesive 12, after the ejection nozzle 13 shown in FIG. 1 is moved to a predetermined position on the inner peripheral side of the upper surface of the disk substrate D1 in a stationary state, the nozzle port 13a is moved to a predetermined position on the upper surface of the disk. The adhesive 12 is discharged while being lowered to the height position and rotating the spindle stage 11 at a low speed.

  Next, as shown in FIG. 2B, the other disk substrate D2 is superposed on the disk substrate D1 with the adhesive 12 interposed therebetween. On the spindle stage 11, the two disk substrates D1 and D2 are overlaid with high accuracy by the alignment action by the fitting of the respective center holes C and the reference pins 11b.

  Next, as shown in FIG. 2C, the spindle stage 11 is driven to rotate the two disk substrates D1 and D2 around the rotation axis 11a at a high speed (for example, 5000 rpm), thereby causing the disk substrates D1 and D2 to move. The sandwiched uncured adhesive 12 is spread toward the outer periphery of the disk by centrifugal force, and the adhesive 12 is spread between the disks. At this time, the surplus portion of the adhesive 12 is shaken off radially outward from between the disk substrates D1 and D2.

  Then, the hardening process of the adhesive agent 12 which concerns on this invention is performed (FIG. 2D, E). In the curing process of the adhesive 12, ultraviolet light is irradiated from above the disk substrate D2, and the adhesive 12 developed between the disk substrates D1 and D2 is cured.

  Therefore, in the present embodiment, the spot light source 14 is moved in the disk radial direction with respect to the disk substrates D1 and D2 on the rotating spindle stage 11, and ultraviolet rays are irradiated in order from the disk inner circumference side toward the outer circumference side. The entire surface is cured while shifting the curing timing of the adhesive 12 on the inner and outer circumferences of the disk (FIGS. 2D and 2E).

  As described above, by varying the irradiation timing of the ultraviolet rays on the inner and outer circumferences of the disc, the adhesive 12 on the outer circumference side is cured sequentially from the adhesive 12 on the inner circumference side of the disc, and the volume decrease due to curing shrinkage is quantitatively increased. Will be appropriated. As a result, it is possible to reduce the deformation of the disk due to curing shrinkage as compared with the case where the adhesive is simultaneously cured on the entire surface of the disk.

  Further, since the spot light source 14 is used as the ultraviolet light source, the thermal deformation of the disk due to the ultraviolet irradiation becomes local, and the thermal deformation amount of the disk can be reduced as compared with the simultaneous irradiation to the entire disk surface. Further, it is possible to eliminate the need for a heat exhaust system that has been conventionally required.

  Furthermore, according to the present embodiment, since the discharge nozzle 13 for the adhesive 12 and the spot light source 14 for ultraviolet UV are respectively installed on the common arm 20, the adhesive application process and the curing process are performed on the same stage 11. Thus, it is possible to prevent sticking displacement due to transfer to the UV stage in an uncured state.

  By the way, in the above-described adhesive curing process, when the rotational speed or rotational speed of the spindle stage 11 (disk substrates D1, D2), the moving speed of the spot light source 14, and the amount of ultraviolet irradiation are constant, the disk substrates D1, D2 are used. Due to the difference in peripheral speed between the inner peripheral side and the outer peripheral side, there is a difference in the amount of ultraviolet irradiation per unit length in the track direction (circumferential direction) at each radial position.

  In order to avoid this, in this embodiment, the ultraviolet irradiation amount per unit length in the track direction is made constant by the following method.

  As a first method, the moving speed of the spot light source 14 is changed from the inner circumference side of the disk toward the outer circumference side while keeping the rotation speed of the spindle stage 11 and the ultraviolet irradiation amount constant.

  In this example, the outer peripheral side of the disk has a higher peripheral speed than the inner peripheral side, so that the movement control unit 19 increases the moving speed of the spot light source 14 gradually from the inner peripheral side of the disk toward the outer peripheral side. By controlling the linear drive source 21 of the moving mechanism 15, the amount of ultraviolet irradiation at each radial position is made uniform. In this case, the controller 22 sends a command to the rotation control unit 16 and the UV control unit 18 so as to make the rotation speed and the ultraviolet irradiation amount of the spindle stage 11 constant, and at the moving position (disk radial position) of the spot light source 14. Based on this, the movement speed control of the arm 20 by the movement control unit 19 is executed.

  As a second method, the rotation speed of the spindle stage 11 is changed as the spot light source 14 moves from the inner circumference side of the disc toward the outer circumference side while keeping the ultraviolet ray irradiation amount and the moving speed of the spot light source constant.

  In this example, the rotation control unit 16 controls the rotational drive of the spindle stage 11 so that the rotational speed of the spindle stage 11 gradually decreases as the light source unit 14 moves from the inner circumference side to the outer circumference side of the disk. The amount of ultraviolet irradiation at the radial position is made uniform. In this case, the controller 22 sends a command to the movement control unit 19 and the UV control unit 18 so as to keep the movement speed and ultraviolet irradiation amount of the spot light source 14 constant, and also sets the movement position (disk radial position) of the spot light source 14. The rotation is sequentially supplied to the rotation control unit 16 and the rotation speed control of the spindle stage 11 is executed.

  As a third method, the UV irradiation amount (irradiation output) is increased as the light source unit 14 moves from the inner circumference side of the disc toward the outer circumference side while keeping the rotation speed of the spindle stage 11 and the moving speed of the spot light source 14 constant. Change.

  In this example, the UV control unit 18 controls the amount of ultraviolet irradiation so that the amount of ultraviolet irradiation from the spot light source 14 gradually increases as the spot light source 14 moves from the inner peripheral side to the outer peripheral side of the disc. The amount of UV irradiation in the system is made uniform. In this case, the controller 22 sends commands to the rotation control unit 16 and the movement control unit 19 so as to keep the rotation speed of the spindle stage 11 and the movement speed of the spot light source 14 constant, and also controls the movement position of the spot light source 14 by UV control. It supplies to the part 18 sequentially, and performs ultraviolet irradiation control.

  As described above, since the amount of ultraviolet irradiation to the adhesive 12 can be made uniform over the entire surface of the disk, the bonding quality of the disk substrates D1 and D2 can be improved, and the signal characteristics are not adversely affected. A highly reliable optical disc D in which deformation is suppressed can be manufactured.

For example, in the conventional optical disk manufactured by simultaneous irradiation of ultraviolet rays on the entire disk surface, the maximum acceleration in the direction of the rotation axis, which is an index of the amount of surface deflection, is about 8 m / s ^2. According to the embodiment, it has been confirmed that the maximum acceleration can be reduced to 5 m / s ² or less. This makes it possible to obtain an optical disc having mechanical characteristics (skew, acceleration) that can withstand, for example, high-speed use at 8 × speed or higher.

  The above-described examples are not limited to being performed alone, and the above-described movement speed control of the spot light source 14, ultraviolet ray irradiation amount control, and spindle stage rotation speed control may be executed in any combination.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

  FIG. 3 shows a second embodiment of the present invention. In the figure, portions corresponding to those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, the curing process of the ultraviolet curable adhesive 12 developed between the two disk substrates D1 and D2 is performed in a state where the weight member 24 having a predetermined weight is placed on the upper disk substrate D2. I am doing so.

  Thus, by performing the curing process of the adhesive 12 with the weight member 24 placed on the disk substrate D2, it is possible to suppress the deformation of the disk due to the curing shrinkage of the adhesive 12 and the heat generated during the ultraviolet irradiation. In addition, it is possible to correct the disc warp caused by the difference in the coating thickness of the adhesive 12 and the internal stress or residual stress in the disc surface in the molding or film forming step before the disc bonding step, and the amount of deformation is small. It becomes possible to manufacture a high-quality optical disc D having excellent signal characteristics.

  The weight member 24 is made of a material that is transparent to ultraviolet rays UV and can correct or prevent warpage and deformation that may occur in the disk D as described above. In this embodiment, the weight member 24 is a transparent glass having a weight of about 200 g. A board is used. Then, the reference pin 11b of the spindle stage 11 is fitted into the hole 24a formed at the center of the weight member 24, and the weight member 24 is rotated together with the disk substrates D1 and D2, as in the above-described embodiment. The spot light source 14 for ultraviolet rays UV is moved from the inner circumference side of the disk to the outer circumference side so that the adhesive 12 is cured from the inner circumference side of the disk.

  In addition, by making the shape of the weight member 24 circular, the pressure distribution acting on the disk substrates D1 and D2 can be equalized. Depending on the shape of the weight member, it is possible to form a desired pressure distribution in the disk surface, so the shape of the weight member may be varied depending on the conditions.

  In particular, if the weight member 24 uses a transparent material having a heat ray shielding function, for example, heat ray reflection glass, or if a heat ray cut filter is provided on the upper surface of the weight member 24, heat generation during ultraviolet irradiation can be reduced. As a result, the disk flatness can be further improved.

  As mentioned above, although each embodiment of this invention was described, of course, this invention is not limited to these, A various deformation | transformation is possible based on the technical idea of this invention.

  For example, in each of the embodiments described above, the spot light source 14 that is an ultraviolet UV irradiation source is moved from the inner peripheral side to the outer peripheral side of the disc. However, the deformation of the disc due to the curing shrinkage of the adhesive 12 can be suppressed. As long as the spot light source 14 is moved from the outer peripheral side of the disk toward the inner peripheral side, the adhesive 12 may be cured from the outer peripheral side of the disk.

  Further, the spot light source 14 is not limited to the case of continuously irradiating the ultraviolet rays UV, but may be irradiated in a pulse shape. In this case, the duty of the generated pulse may be made variable to adjust the ultraviolet ray irradiation amount at the disk radial position.

  In each of the above-described embodiments, the step of bonding the disk substrates D1 and D2 for DVD use has been described. However, the present invention can also be applied to the manufacture of bonded optical disks other than DVD.

1 is a schematic configuration diagram of an optical disc manufacturing apparatus 10 according to a first embodiment of the present invention. It is process sectional drawing explaining the disk bonding method of this Embodiment. It is a schematic diagram explaining the disk bonding method by the 2nd Embodiment of this invention. It is process sectional drawing explaining the conventional disc bonding method.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Optical disk manufacturing apparatus, 11 ... Spindle stage, 12 ... Ultraviolet curable adhesive, 13 ... Discharge nozzle, 14 ... Spot light source, 15 ... Movement mechanism, 16 ... Rotation control part, 17 ... Discharge control part, 18 ... UV control Reference numeral 19: Movement controller, 20: Arm, 21: Drive source, 22: Controller, 24: Weight member, D: Optical disk, D1, D2: Disk substrate, UV: Ultraviolet light

Claims (10)

A step of applying an ultraviolet curable adhesive on the upper surface of the first disk placed on the rotatable holding member, and a step of superimposing the second disk on the first disk via the adhesive And rotating the holding member to spread the adhesive between the two disks by centrifugal force, and curing the adhesive by irradiating ultraviolet rays from above the second disk. A method for laminating discs,
In the step of curing the adhesive, a light source capable of irradiating ultraviolet rays in a spot shape is used, and the irradiation timing of the ultraviolet rays is made different between the inner peripheral side and the outer peripheral side of the disk rotating on the holding member. Disc sticking method. The disk bonding method according to claim 1, wherein, in the step of curing the adhesive, the light source is moved from the inner circumference side of the disk toward the outer circumference side. 3. The disk laminating method according to claim 2, wherein in the step of curing the adhesive, the moving speed of the light source is changed so that the amount of ultraviolet irradiation per unit length in the track direction is constant. . The disk bonding method according to claim 2, wherein in the step of curing the adhesive, the rotational speed of the disk is changed so that the amount of ultraviolet irradiation per unit length in the track direction is constant. . 3. The disk attachment according to claim 2, wherein in the step of curing the adhesive, the amount of ultraviolet irradiation from the light source is changed so that the amount of ultraviolet irradiation per unit length in the track direction is constant. How to match. The disc bonding method according to claim 1, wherein the step of curing the adhesive is performed by placing a weight made of a transparent material on the other disc. An apparatus for manufacturing an optical disc in which two discs are bonded together via an ultraviolet curable adhesive,
A holding member for rotatably holding the disk;
A supply section of the adhesive;
A light source that emits ultraviolet rays in a spot shape;
An optical disc manufacturing apparatus comprising: irradiation means for changing the irradiation timing of the ultraviolet rays between an inner peripheral side and an outer peripheral side of the disc. The optical disk manufacturing apparatus according to claim 7, wherein the irradiation unit includes a moving mechanism that moves the spot light source between an inner peripheral side and an outer peripheral side of the disk. A control means is provided for controlling at least one of the number of rotations of the holding member, the output of the spot light source, and the moving speed so that the amount of ultraviolet irradiation per unit length in the track direction is constant. The optical disk manufacturing apparatus according to claim 8. The optical disk manufacturing apparatus according to claim 7, further comprising a weight for applying a predetermined load between the two disks on the holding member, and the weight having a heat ray shielding function.

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