JP2003231866A - Method for joining body, joining device, and device for producing disc - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for joining plate bodies, capable of stably forming an electrical field so as to make safely and stably an adhesive raised, and therefore capable of preventing bubbles from being mixed into the adhesive, when the plate bodies are together joined. <P>SOLUTION: In this method for joining two of the plate bodies comprising disc bases 1a, 1b, an ultraviolet-curing resin composition is applied to the disc base 1a, and the electric field is formed on one of surfaces of the disc base 1b other than the surface to which the disc base 1a is joined in such a manner that the electric field corresponds to the applied resin composition, so that the formed electrical field penetrates the disc base 1b, acts on the applied ultraviolet-curing resin composition, and makes inductive charges developed on the surface of the resin composition. Because Coulomb's force acts on the inductive charges, the surface of the ultraviolet-curing resin composition is raised toward the disc base 1b, so that an initial contact area between the ultraviolet-curing resin composition and the disc base 1b is made to be small. And, a contact region of the ultraviolet-curing resin composition is gradually enlarged from the initial contact area as a starting point, then air exiting between the disc bases is pushed off by the ultraviolet-curing resin composition, so that the bubbles are prevented from being mixed into the composition. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for joining two objects with a liquid adhesive, and for example, two disk substrates are bonded together with a liquid adhesive to produce one disk. Technology.

[0002]

2. Description of the Related Art In the case of joining two objects with a liquid adhesive, if air bubbles are caught in the joining interface, the assembly accuracy after joining is lowered, and the joining strength and durability are also lowered. is there. Furthermore, in the bonding of optical elements such as prisms, lenses and filters, or in the bonding of these optical elements and light receiving elements, the presence of bubbles at the bonding interface significantly reduces the optical performance. In addition, if air bubbles enter the bonding interface of glass, transparent plastic, or a composition made of a laminate of these, the aesthetic appearance thereof is significantly impaired. As described above, preventing bubbles from entering the bonding interface is a universal problem in various fields, and many proposals have been made so far.

For example, Japanese Patent Laid-Open No. 07-335512 discloses a method of joining two substrates without using an adhesive equivalent to a normal adhesive, after deforming one substrate into a convex shape at the center, A method is disclosed in which a voltage is applied between two substrates when they are brought into contact with the other substrate and the bonding portion is expanded to the periphery so that the curvature of the non-contact portion does not change.

Also, in Japanese Patent Laid-Open No. 2000-290602, when two plate-like objects are bonded together via an adhesive, an electric field is applied to the space between the bonding surfaces for at least a part of the period before bonding. A method of forming, raising an adhesive and then laminating is disclosed.

All of these known methods utilize electrostatic force to suppress bubble generation,
The point of forming an electric field in order to develop an electrostatic force, and the point of forming an electric field is that it is provided by sandwiching two plate-like objects to be joined, and is performed by a pair of electrodes approaching each other as the plate-like objects approach each other. Etc. are in agreement.

Incidentally, in order to generate a desired electrostatic force, it is usually necessary to generate an electric field having a magnitude of several kV / cm to several tens of kV / cm. In the case of the electrode pair of the type, the magnitude of the voltage to be applied at that time depends on the thickness of the two target plate-like objects, but generally the higher the thickness and the greater the distance between the electrodes, the higher the voltage. Will be needed.

[0007]

In a circuit to which a high voltage is applied, it is natural that the electric insulation must be taken into consideration to prevent electric shock accidents. However, as described above, in the case where the electrode pair for generating the electric field is provided so as to sandwich the two plate-like objects, not only a higher voltage is required if the distance between the electrodes is long, but also Since the electrode pairs are provided separately from each other, electrical insulation must be taken into consideration, and the complexity of circuit design has been a problem.

Further, in the above case, if the value of the applied voltage is kept constant, there is a problem that the distance between the electrodes is reduced when the plate-like objects are superposed and the electric field is increased. The electric field increases and its magnitude is 3
When it exceeds 0 kV / cm, air causes dielectric breakdown and causes various discharge phenomena such as corona discharge and spark discharge,
In addition to destroying the plate-shaped object, if the adhesive is flammable, it may cause a fire, which is extremely dangerous.

In order to avoid such a problem, it is necessary to maintain the electric field at a desired magnitude. For that purpose, the applied voltage is reduced in proportion to the reduction in the distance between the electrodes to make the magnitude of the electric field constant. It is conceivable that the control is performed so as to maintain it, but in that case, it is necessary to separately provide a control mechanism, and it is easily expected that the specification of the manufacturing line needs to be changed and the cost will increase.

The present invention has been made in view of the above circumstances, and allows an electric field to be stably formed when objects are bonded together to safely and effectively raise the adhesive to prevent bubbles from entering. The purpose is to prevent.

[0011]

As means for solving the above problems, the present inventor has decided to adopt the following joining method and joining apparatus for objects. That is, the method for joining objects according to the present invention is a joining method for joining two objects using a liquid adhesive, and a step of applying the adhesive to one object and sandwiching the adhesive between the one object. And the step of superimposing the other object on each other, and at the time of superimposing, an electric field acting on the adhesive is formed between the two objects by the electric field forming means installed on the surface side different from the superposing surface of the other object. It is characterized by An object joining apparatus according to the present invention is a joining apparatus for joining two objects using a liquid adhesive, and includes an application unit for applying an adhesive to one object and an adhesive for one object. It is characterized in that it is provided with a superposing means for superposing the other object with the other object sandwiched therebetween, and an electric field forming means for forming an electric field acting on the adhesive on a surface side different from the superposing surface of the other object. According to the present invention, when superposed, the electric field penetrates the other object and acts on the adhesive surface, the adhesive is raised toward the other object, and the contact area of the adhesive spreads between the two objects. You can join two objects without entraining air bubbles.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, in the case of stacking objects, the first electrode and the second electrode have a flat plate-to-plate electrode structure on the side different from the stacking surface of the other object. Corresponding to the adhesive applied to one of the objects, not the uniform (uniform) electric field that is formed between the electrode plates, but the non-uniform (nonuniform) electric field that is formed, for example, in the flat pair electrode configuration To form. This electric field penetrates the other object, preferably a plate-like object, and acts on the adhesive, and an induced charge appears on the surface of the adhesive. The electric field formed in the space opposite to the plate electrode centering on the line electrode may be referred to as "leakage electric field". At the time of superposition, this leakage electric field penetrates the other object, and the adhesive surface charge induced thereby is
It receives a mechanical action from the leakage electric field. The acting direction of the force is a direction in which the adhesive surface and the object overlapping surface are always attracted to each other. Therefore, the surface of the adhesive is raised toward the other object. This ridge reduces the initial contact area between the adhesive and the other object, and the contact area of the adhesive between the two objects expands starting from this small initial contact point, and the air that exists between the two objects adheres. Since it is extruded into the agent, air bubbles are not caught between the object and the adhesive agent.

In the joining method according to the present invention, the object is a disk substrate, the adhesive is an ultraviolet curable resin composition, and D
VD (Digital Video / Versatile Disc)-
It can be performed in the process of laminating optical disks such as RAM and DVD-ROM. As a result, it is possible to improve the assembling accuracy after bonding, improve the bonding strength and durability, and further, the appearance of the disk can be finished beautifully.

In the joining method according to the present invention, the electric field forming means includes a plate-shaped electrode as a first electrode arranged on a surface side different from the overlapping surface of the other plate-shaped object, and the plate-shaped electrode It is preferable to have a linear electrode as a second electrode arranged at a fixed position apart from each other, and to have a voltage applying means for applying a voltage between both electrodes. Rather than making the electrodes for forming an electric field the same shape as each other, make one close to the other object linear and mold the linear electrode according to the adhesive applied to one plate object. As a result, an electric field is concentratedly formed in accordance with the shape of the adhesive applied, and the induced charges of the adhesive also appear concentratedly in a narrow area of the adhesive surface. This promotes the bulging of the adhesive and reduces the initial contact area between the adhesive and the other object, so that it is possible to prevent air bubbles from being mixed at the first contact.

In the joining method according to the present invention,
It is preferable that the adhesive is applied to a clamp area provided on the inner peripheral portion of the disc substrate in a concentric pattern with the disc substrate. A metal thin film is formed as an information recording layer on at least one of the two disk substrates. When these two disk substrates are faced to each other and an electric field is applied to the two disk substrates, electrostatic discharge by the metal layers is caused. The shielding action makes it difficult to obtain a leakage electric field sufficient to cause the adhesive to rise. Here, turning to the inner peripheral portion of the disc substrate, a clamp area having no information recording layer is provided in this portion so that the disc as a product can be held in the reproducing device without any trouble. Therefore, in the present invention, an adhesive is applied to this clamp area concentrically with the disk substrate, and an electric field is directly applied to the adhesive without passing through the information recording layer, thereby causing the phenomenon of capacitor formation of the information recording layer. Without it, a relatively low voltage can cause adhesive bulge.

In the bonding apparatus according to the present invention, as described above, the electric field forming means is a plate-shaped electrode as a first electrode disposed on the surface side different from the superposing surface of the other object, and the plate. It is preferable to provide a linear electrode as a second electrode which is different in shape from the plate electrode and is arranged at a fixed position apart from the plate electrode, and a voltage applying means for applying a voltage between these two electrodes. Furthermore, it is preferable that the linear electrode is formed according to the application shape of the adhesive applied to one of the objects. The width of the linear electrode in this case is 0.
It is preferably 5 mm or less. It has been confirmed that the bulging of the adhesive agent positively occurs in this range and the generation of bubbles is drastically reduced.

The linear electrode is composed of, for example, a metal wire. Since the metal wire is available at a relatively low cost and is easy to handle, the electrode can be manufactured easily and at low cost. Alternatively, the linear electrodes may be thin film electrodes. In this case, for example, ion beam sputtering,
Ion beam etching, DC magnetron sputtering,
By using a thin film forming technique such as RF magnetron sputtering, an extremely fine linear electrode can be formed with high accuracy. It is also possible to form a linear electrode having a complicated shape that is difficult to manufacture with a metal wire.

When the bonding method according to the present invention is carried out in the above-mentioned laminating step of various optical disks, it is preferable to use a disk manufacturing apparatus having the following structure.
That is, the disc manufacturing apparatus according to the present invention is a laminating apparatus for laminating two disc substrates using a liquid adhesive, and a coating means for coating one disc substrate with the adhesive and one disc substrate. An overlaying means for overlaying the other disk substrate with an adhesive sandwiched between the substrates,
On the surface side different from the overlapping surface of the other disk substrate,
An electric field forming means for forming an electric field corresponding to the adhesive applied to one of the disk substrates is provided.

In the disk manufacturing apparatus according to the present invention, it is preferable that the stacking means is provided with a holding means for holding the other disk substrate on a surface different from the stacking surface, and the holding means is provided with an electric field forming means. . To bond two disk substrates together, at least one of them must be held and stacked on top of each other, but if one disk substrate coated with an adhesive is to be held and moved. As a result, the adhesive drips or the applied shape is changed, and uniform working accuracy cannot be obtained. Therefore,
It is preferable that one disk substrate coated with an adhesive be stationary and the other disk substrate be held and superposed on it, but the other disk substrate has an electric field on the side different from the superposing surface. Forming means must be provided. According to the present invention, the electric field forming means can be installed by holding the other disk substrate at the time of bonding, so that a series of bonding operations are simplified and the productivity is improved. The electric field forming means may be replaceable with a different electric field forming position. When the outer diameters of the disk substrates are different, the amount of adhesive applied is increased or decreased according to the increase or decrease of the outer diameter, but the adhesive applied when the two disk substrates are joined is not spread inside. ,
In order to perform the spreading appropriately like the outward spreading, it is necessary to adjust not only the coating amount but also the coating position of the adhesive. Therefore, if a plurality of electric field forming means having different electric field forming positions are provided and the electric field forming means is replaced and the electric field forming position is adjusted to correspond to the adhesive applying position in accordance with the change in the adhesive applying position. Good.

In the disk manufacturing apparatus according to the present invention, as in the above-described joining apparatus, the electric field forming means is composed of a plate electrode, a linear electrode arranged at a fixed position separated from the plate electrode, and both of these electrodes. It is preferable to provide a voltage applying means for applying a voltage between the electrodes, and the linear electrode is preferably formed according to the application shape of the adhesive agent applied to one plate-like object. Also in this case, the width of the linear electrode is 0.5 mm.
The following is preferable.

Further, in the disk manufacturing apparatus according to the present invention, in order to carry out the above-mentioned joining method, the coating means is provided in the clamp area provided on the inner peripheral portion of the disk substrate, and the adhesive is concentric with the disk substrate. It is preferably provided so as to be applied in a striped manner.

[0022]

EXAMPLE An example of the present invention will be described by taking the manufacture of a DVD as an example. FIG. 1 shows a schematic configuration of a DVD manufacturing apparatus. In the figure, reference numerals R1 and R2 are both disc substrate ejecting portions, R3 is a disc producing portion, R4 is a disc inspecting portion, and R5 is a disc ejecting portion, both of which are housed inside a case (not shown).

The disk substrate take-out portion R1 is a stock device 3 for stocking one of two disk substrates, which are bonded together to form one disk (DVD), in a state of being stacked on a disk holder 2, and a disk holding device. The disk substrate 1a held in the container 2 is taken out one by one.

Similarly, the disk substrate take-out section R2 stocks the other of the two disk substrates.
And a take-out device 4 for taking out the stocked disk substrates 1b one by one.

The disc producing section R3 is provided with a disc substrate 1a.
A coating device (coating means) 5 for coating the ultraviolet curable resin composition (in this case, a cationic polymerization type ultraviolet curable resin composition) S as an adhesive on the superposed surface of the sheet and the ultraviolet curable resin composition S. An ultraviolet irradiator 6 for irradiating the coated disk substrate 1a with ultraviolet rays, and a disk substrate 1b superposed on the disk substrate 1a with the applied ultraviolet curable resin composition S interposed therebetween to form one disk 1. A device (overlapping means) 7, a spreading device 8 for circumferentially rotating and spreading the superposed disc substrates 1a and 1b, and a flash including light including ultraviolet rays and infrared rays on the finished disc 1. It is configured by an end surface processing device 9 which irradiates the end surface to perform an end surface hardening process, and a flat surface holding device 10 which holds the disk 1 which has been subjected to the end surface processing flat for a predetermined time.

As shown in FIGS. 2 and 3, the superposing device 7 is provided at an end portion of an elevating plate 20 for placing and elevating the disc substrate 1a coated with the ultraviolet curable resin composition S and for elevating the disc substrate 1a. Disc substrate holding device (holding means) 21
And a reversing arm 22 which holds the disk substrate 1b and swings with its base end supported by a shaft.

The elevating plate 20 forms a part of the coating / bonding stage B, and is at a predetermined position (overlapping position B4).
The disk substrate 1a moved to the actuator 20
It is adapted to be lifted in the vertical direction by driving a.

The disc substrate holding device 21 includes a substrate receiving portion 23 that abuts on the clamp area of the disc substrate 1b.
A plurality of vacuum suction sections 24 are provided around the substrate receiving section 23 and suction the vacuum area to the clamp area. The vacuum suction unit 24 is connected to a suction device 26 via an air passage 25. The disk substrate 1 is located at the center of the substrate receiving portion 23.
A center boss 27 to be inserted into the center hole of b is provided.

In the disc substrate holding device 21, an electric field forming device (electric field forming means) for transmitting an electric field through the disc substrate 1b to the ultraviolet curable resin composition S applied to the disc substrate 1a during superposition. ) 28 is provided. The electric field forming device 28 includes the ultraviolet curable resin composition S.
A plate-like electrode 29 (first electrode) formed in an annular shape corresponding to, and a linear electrode 30 (second electrode) also formed in an annular shape corresponding to the ultraviolet curable resin composition S, Voltage applying device (voltage applying means) 31 for applying a voltage between both electrodes
It has and. One plate electrode 29 constituting the electric field forming means 28 is provided on a side surface different from the substrate side of the electrically insulating solid body 32 forming the substrate receiving portion 23, and the other linear electrode 30 is also electrically insulated. It is embedded inside the sex medium 32, and both electrodes are completely electrically insulated from the adjacent structure and the external space. Further, both the plate-shaped electrode 29 and the linear electrode 30 are arranged at fixed positions apart from the disc substrate 1b which is in contact with the substrate receiving portion 23 with the center boss 27 as the center, and the linear electrode 30 is plate-shaped. It is provided at a position closer to the disc substrate 1b than the electrode 29. The voltage applying device 31 itself is provided outside, and is connected to the plate electrode 29 and the linear electrode 30 via the conductive wire 33 arranged on the reversing arm 22.

The plate electrode 29 is manufactured by using a thin film forming technique such as ion beam sputtering, ion beam etching, DC magnetron sputtering, RF magnetron sputtering. The linear electrode 30 is manufactured by bending a metal wire having a width (thickness) of 0.5 mm or less.

As shown in FIG.
A plurality of peripheral circuits 41, 42, 43, and a first elevating device 44 for elevating between the upper peripheral circuit 41 and the middle peripheral circuit 42,
A second elevating device 45 that elevates and lowers between the middle circuit 42 and the lower circuit 43, and a third elevating device 46 that elevates and lowers between the upper circuit 41 and the lower circuit 43. There is. A plurality of flat surface holding units 48 are movably installed in each of the peripheral circuits 41, 42, 43. The flat surface holding unit 48 sucks the air with a fan provided inside to suck the disk 1 onto a flat holding member and hold it in a planar shape. These flat surface holding units 48 are configured so that the bonded discs 1 are placed and each circuit is circulated in the order of the upper stage, the middle stage, and the lower stage, and finally returns to the upper stage peripheral circuit 41 again.

FIG. 5A is a plan view of the plane holding unit 48 as seen from above, and FIG. 5B is a side view. The flat surface holding unit 48 has wheels 50 fixed to the bottom surface of a housing 49 having openings on the bottom surface and the top surface, and an electric fan 51 is incorporated inside the housing 49. Case 4
On the upper surface of the first through hole 52 and the second through hole 5,
A flat plate-shaped holding member 54 having a number 3 is attached. Further, at the center of the holding member 54, a protrusion 55 that fits into the central hole H1 of the disc 1 is provided.

The disk inspection section R4 is composed of a disk inspection device 11 which inspects the disk 1 and judges whether the disk 1 is good or bad. The disc payout unit R5 includes a nondefective product payout unit 12 that pays out the disc 1 that is determined to be a non-defective product, and a defective product payout unit 13 that pays out the disc 1 that is determined to be a defective product.

Next, the manufacturing process of the disc 1 by the DVD manufacturing apparatus configured as described above will be described. First, in the disk substrate take-out section R1, the stock device 3
The stock stage A, which constitutes the above, rotates in the direction of the arrow in the figure, and one of the plurality of disk holders 2 installed on the stage moves to the substrate extraction position A1 to prepare for the substrate extraction by the extraction device 4. On each disc holder 2, disc substrates 1a and spacers (not shown) are alternately laminated. The take-out device 4 is provided with two arms 4a and 4b which are driven synchronously, and the uppermost one of the disc substrates 1a held by the disc holder 2 at the substrate take-out position A1 is the arm. It is conveyed to the substrate receiving position B1 on the coating / bonding stage B by 4a. Also,
During the return operation of the arm 4a, the spacer held by the disk holder 2 at the substrate take-out position A1 is conveyed to the spacer collector 14 by the arm 4b and collected.

Similarly, in the disk substrate unloading section R2, the stock stage A constituting the stocking device 3 rotates in the direction of the arrow in the drawing, and one of the plurality of disk holders 2 installed on the stage picks up the substrate unloading position A1. Move to. Subsequently, the uppermost one of the disc substrates 1b held by the disc holder 2 at the substrate take-out position A1 is conveyed to the stacking device 7 by the arm 4a, and transferred to the reversing arm 22 to hold the disc substrate. It is adsorbed and held by the device 21. Further, during the return operation of the arm 4a, the spacer held by the disk holder 2 at the substrate take-out position A1 is conveyed to the spacer collector 14 by the arm 4b and collected.

The disk substrate 1a transported to the substrate receiving position B1 moves to the adhesive coating position B2 as the coating / bonding stage B rotates in the direction of the arrow in the figure. The ultraviolet curable resin composition S is linearly applied to the overlapping surface of the disc substrate 1a which has been moved to the adhesive application position B2 by the application device 5 so as to draw a concentric ring in the clamp area of the disc substrate 1a. To be done. The coating amount here is as uniform and quantitative as possible in the circumferential direction.
It is desirable to carry out only the required amount. It is the following 2
For one reason. One is that, as described above, the ultraviolet curable resin composition S applied in a required amount or more is followed by irradiation of the composition with ultraviolet rays, superposition with the disk substrate 1b, and rotational spreading as described above. At the time of the rotational spreading, it scatters from the end portion of the bonded disc 1 and then hardens. The cured UV-curable resin composition cannot be reused as an adhesive and is therefore discarded. For this reason, it is desirable that the amount of waste is as small as possible, and therefore, it is desirable that the amount of application here is only the required amount in advance. The second reason is related to the coating of the ultraviolet curable resin composition S in the clamp area of the disk substrate 1a. According to the verification by the present inventors, the ultraviolet curable resin composition S Although there is a difference depending on the viscosity, when the coating amount exceeds about 800 mg, the line width of the ring-shaped coating material after coating becomes wide, and after the next step, the disk substrate 1b is superposed and then subjected to the rotary spreading step. This is because the ultraviolet-curable resin composition protrudes from the holes in the inner peripheral portion of the bonded disc 1 before the transfer, and at this point the cause of poor finish is already created. As the ultraviolet curable resin composition S, a cationic polymerization type ultraviolet curable resin composition having a light absorption coefficient in the wavelength region of 310 to 340 nm of 2 × 10 ³ m ⁻¹ or less is used. Such an ultraviolet curable resin composition is used as a photopolymerization initiator in an amount of 350
It is obtained by selectively using a material having a relatively small light absorption coefficient of nm or less.

The disk substrate 1a coated with the ultraviolet curable resin composition S moves to the ultraviolet irradiation position B3 as the coating / bonding stage B rotates in the direction of the arrow in the figure. The superposed surface of the disk substrate 1a which has moved to the ultraviolet irradiation position B3 is irradiated with ultraviolet rays from the ultraviolet irradiation device 6 and a reactive species for curing the ultraviolet curable resin composition S is planted. Disk substrate 1 irradiated with ultraviolet rays
A is moved to the superposition position B4 as the coating / bonding stage B is rotated in the direction of the arrow in the figure, and is placed on the elevating plate 20.

When the disc substrate 1a is placed on the elevating plate 20, the disc substrate 1b is inverted together with the reversing arm 22, and the disc substrate 1a is placed at a predetermined distance from the disc substrate 1a with the stacking surface facing the disc substrate 1a. Are placed in parallel with each other. At this time, the electric field forming device 28 is activated to form an electric field on the surface side of the disk substrate 1b different from the overlapping surface. Subsequently, the disc substrate 1a approaches the disc substrate 1b as the elevating plate 20 rises, and the two substrates are bonded by being superposed on each other with the ultraviolet curable resin composition S interposed therebetween to form one disc 1. . The reversing arm 22 which entrusts the disc substrate 1b to the elevating plate 20 is reversed again and returns to its original position.

The disc 1 that has been bonded is transported to the spreading device 8A by the transport arm 15. In the spreading device 8A, the disc 1 is gripped using the central hole,
The ultraviolet curable resin composition is spread by using centrifugal force by being rotated at high speed in its own circumferential direction. Thereby, the ultraviolet curable resin composition between the disk substrates 1a and 1b is spread in a layer having a uniform thickness. Further, at this time, the central axes of the disk substrates 1a and 1b are aligned with each other to align the axes. It should be noted that the spreading device 8 is provided with two systems, but this requires a longer spreading process than the bonding of the disk substrates 1a and 1b, which impairs the productivity of continuous disk manufacturing. Is to eliminate
By alternately passing the disks 1 to the two spreading devices 8A and 8B and executing the spreading simultaneously, it is possible to substantially halve the time required for spreading.

In the process of moving from B3 to B4 in accordance with the rotation of the coating / bonding stage B, some process trouble occurred and the entire bonding device was temporarily stopped. Substrate 1a,
Alternatively, the disc 1 in which a similar stagnation has occurred in the bonding process is not conveyed to the spreading device 8 but moves to the defective product dispensing position B5 as the coating / bonding stage B rotates. The defective product delivery position B5 is provided in order to exclude a defect in a work-in-process from an early stage, and the disc substrate 1a or the disc 1 that has been moved to this position is
The transfer arm 16 transfers the film to the defective product shooter 17 and removes it. The stagnation is a work-in-progress defect for the following reasons. When a curing reaction species is planted in the ultraviolet curable resin composition S by ultraviolet irradiation, the curing reaction occurs immediately after that and the viscosity starts to increase. Therefore, the time from the ultraviolet irradiation to the spreading is different for each bonded disc. From the viewpoint of improving the yield, it is desirable that the value of 1 is always kept constant. On the other hand, with the ultraviolet curable resin composition S which has passed a predetermined time or longer due to some process trouble, spreading due to high speed rotation is no longer difficult, and it can be judged as a clear defect without turning to the next process.

The disc 1 on which the ultraviolet curable resin composition has been spread is conveyed to the disc receiving position C1 on the end surface processing stage C by the conveying arm 18. The disc 1 conveyed to the disc receiving position C1 is moved to the end face processing position C2 as the end face processing stage C is rotated in the direction of the arrow in the drawing.
Moved to. At the end surface processing position C2, both the front and back surfaces of the disk 1 are flashed by the end surface processing device 9 with light rays including ultraviolet rays and infrared rays. At this time, the end surface of the disk 1 is also irradiated by using a reflection mirror or the like. Thereby, the curing of the ultraviolet curable resin composition in the vicinity of the end face is promoted and the protrusion of the composition from the end face is prevented, and the curing time of the entire ultraviolet curable resin composition is heated by the heat rays. Is shortened.

The disk 1 which has undergone the end surface processing is transferred to the transfer position C by the rotation of the end surface processing stage C in the direction of the arrow in the figure.
3, and the plane holding device 10 is moved by the transfer arm 19.
Be transported to. As shown in FIG. 4, the disc 1 is first placed on the plane holding unit 48 located at the loading position D1 of the upper peripheral circuit 41. The flat surface holding unit 48 on which the disk 1 is placed makes a half turn around the circumferential circuit 41 and is placed on the first lifting device 44. The first lifting device 44 mounts the flat surface holding unit 48 and descends to the peripheral circuit 42 in the middle stage. The plane holding unit 48 that has descended to the middle circuit 42 is mounted on the second elevating device 45 this time by making one circuit around the circuit 42 in the opposite direction.
The second lifting device 45 mounts the flat surface holding unit 48 and descends to the peripheral circuit 43 in the lower stage. The flat surface holding unit 48 that has descended to the lower peripheral circuit 43 is mounted on the third elevating device 46 this time, again making one round of the peripheral circuit 43 in the opposite direction. The third lifting device 46 mounts the flat surface holding unit 48 and ascends to the upper peripheral circuit 41. The flat surface holding unit 48 that has returned to the upper circumferential circuit 41 completes the remaining half of the circumferential circuit 41 for the discharge position D.
Up to 2.

From the loading position D1 to the discharging position D2 of the flat surface holding unit 48, the disk 1 on the flat surface holding unit 48 is held flat, and the curing of the ultraviolet curable resin composition proceeds during this time. Then, the shape of the bonded disc 1 is hardened. The disk 1 that has been cured in the flat surface holding device 10 is removed from the flat surface holding unit 48 that has reached the ejection position D2, and the disk inspection device 1
1 is transported.

In the disc inspection apparatus 11, the discs 1 determined to be defective are removed from the regular line, and only the discs 1 determined to be non-defective are discs on the disc stock table E provided in the non-defective item dispenser 12. The disk holder 2 is stacked on the holder 2 and is conveyed to the subsequent process together with the disk holder 2.

The disk 1 is manufactured through the above steps, but when the disk substrates 1a and 1b are bonded together,
Between both the substrates, the electric field formed by the electric field forming device 28 passes through the disk substrate 1b and acts on the ultraviolet curable resin composition S, and induced charges appear on the surface thereof. The Coulomb force acts on this induced charge, and the ultraviolet curable resin composition S
Since the surface of the swells toward the disk substrate 1b, the initial contact area between the ultraviolet curable resin composition S and the disk substrate 1b becomes small. Then, the contact area of the ultraviolet curable resin composition S between the disk substrates 1a and 1b spreads from this portion as a starting point, and the air existing between the both substrates is pushed out from the end surface of the substrate by the ultraviolet curable resin composition S. Therefore, bubbles are not caught between the disk substrates 1a and 1b and the ultraviolet curable resin composition S.

In this case, since the plate electrode 29 and the linear electrode 30 forming the electric field forming device 28 are both arranged on one side of the disk substrate 1b, and the distance between both electrodes is fixed, Since the magnitude of the electric field does not change even when the disk substrate 1a is brought close to the disk substrate 1b, various discharge phenomena such as corona discharge and spark discharge do not occur, and it is not necessary to strictly control the timing of voltage application. .

Further, instead of making both electrodes the same shape, one side near the disk substrate 1a is made linear and this linear electrode 30 is made to match the ultraviolet curable resin composition applied to the disk substrate 1a. Since it is molded, an electric field is concentratedly formed as if it conforms to the coating shape (ring shape) of the UV curable resin composition, and the induced charge is also generated in a narrow area on the surface of the UV curable resin composition. Appears concentrated.
As a result, the protrusion of the ultraviolet curable resin composition is promoted, the tip of the protrusion rises sharply, and the initial contact area with the disk substrate 1b becomes smaller, which also prevents the inclusion of bubbles.

Further, in the above manufacturing process, the ultraviolet curable resin composition is applied to the clamp area of the disc substrate 1a while avoiding the information recording layer, and is directed toward the ultraviolet curable resin composition without the information recording layer. Since the electric field is directly applied, the adhesive can be raised even at a relatively low voltage without being affected by the electrostatic shielding effect of the information recording layer which is a conductor.

Next, a modified example of the DVD manufacturing apparatus according to the embodiment of the present invention will be described with reference to FIGS. 6 and 7, and the same or similar parts and members as those in the above embodiment will be described with the same reference numerals. Omit it. There are several types of discs (DVDs) having different outer diameters, for example, outer diameter φ
Some are 120 mm and φ80 mm. After manufacturing a disk of φ120 mm, when manufacturing a disk in which the disk substrates 1a and 1b of φ80 mm are bonded together in the same apparatus, in order to eliminate the ultraviolet curable resin composition S scattered to the outside as much as one ultraviolet ray It is necessary to reduce the coating amount of the curable resin composition S. In this case, when the amount of the ultraviolet curable resin composition S applied to the disk substrate is reduced, it becomes difficult to spread the inside of the disk during spreading, which may cause a disc adhesion failure or the like. In order to eliminate such inconvenience, it is necessary to change the coating position of the ultraviolet curable resin composition S according to the change of the outer diameter dimension of the disc substrates 1a and 1b, and to increase or decrease the outer diameter of the disc substrates 1a and 1b. Accordingly, the diameter of the ultraviolet curable resin composition S applied in an annular shape is increased or decreased concentrically. However, when the coating diameter of the ultraviolet curable resin composition S is reduced (or increased),
The annular coating position and the (plate electrode 29 of the electric field forming device 28
And) The position of the linear electrode 30 is deviated from the opposite position. Therefore, the ultraviolet curable resin composition S is displaced from the position where the electric field is applied, and the protrusion phenomenon of the ultraviolet curable resin composition S does not appear when the electric field is formed.
In the worst case, there is a problem that the ultraviolet curable resin composition S that spreads at the time of bonding holds air bubbles. This modification is designed to solve such a problem.

That is, FIG. 6 shows an electric field forming device according to a first modification, wherein (a) is a side view and (b) is a plan view seen from the substrate receiving portion side. The electric field forming device 60 shown in the figure corresponds to the disc substrate holding device 7 shown in FIG.
The suction device 26, the vacuum suction unit 24, and the air passage 25 are shown in FIG.
Is omitted in. In the electric field forming device 60, the electrode portion 61 and the electrode mounting arm 62 are integrally formed. The electrode portion 61 is formed, for example, in a substantially columnar shape, and in the electrically insulating solid body 32 of the electrode portion 61, a substantially ring-shaped plate electrode 29 and a linear electrode 30 are concentrically opposed to each other and extend in the central axis direction. It is arranged in a state of being spaced apart and embedded. Therefore, the plate electrode 29 is arranged at a position relatively distant from the substrate receiving portion 23 which is one end face of the electrode portion 61, and the linear electrode 30 is arranged at a position relatively close to the substrate receiving portion 23. There is. The conductive wires 33 connected to the plate electrode 29 and the linear electrode 30, respectively, extend in the electrode mounting arm 62 and are connected to a terminal (not shown) provided at the free end 62a. The free end 62 a of the electrode mounting arm 62 will be connected to the power socket of the voltage applying device 31. The electrode mounting arm 62 is provided at a predetermined position facing the elevating plate 20 of the disk substrate holding device 7 at a predetermined position.
A positioning hole 63 is provided for mounting the.
The electric field forming device 60 configured as described above is provided with a plurality of electric field forming devices having the same outer diameter dimension, and in these electric field forming devices 60, at least the outer diameter dimensions of the linear electrodes 30 are different from each other. . The electric field forming device 60 includes a suction device 26, a vacuum suction portion 24, and an air passage 25.
It may be configured separately from.

As described above, depending on the diameter of the ultraviolet curable resin composition applied to one of the disks in an annular shape, an electric field forming device suitable for the diameter is used properly. That is, φ12
In the case of manufacturing a 0 mm disk, the linear electrode 30 (and the plate-shaped electrode 2 is used because the ultraviolet curable resin composition S applied in an annular shape on one disk substrate 1a has a relatively large diameter.
The electric field forming device 60 having a relatively large diameter of 9) having a diameter substantially the same as the diameter of the ultraviolet curable resin composition S is installed facing each other to form an electric field. Also, for example, φ80 mm
One disc substrate 1a when manufacturing other discs
Since the ultraviolet curable resin composition S applied to the surface of the electric field forming device 60 has a comparatively small diameter, the diameter of the linear electrode 30 (and the plate electrode 29) is comparatively small (for example, about 4 mm in diameter). Then, it is attached and an electric field is formed. According to the diameter of the annular ultraviolet curable resin composition S set by the disc to be manufactured in this manner, the electric field forming device 60 having the linear electrode 29 of the corresponding diameter is selected to select the disc substrate holding device. When it is mounted on No. 7, the ultraviolet curable resin composition S can be surely contained within the electric field working range, a bulging phenomenon at the time of bonding can be expressed, and air bubbles can be prevented from being mixed.

In the electric field forming device 70 according to the second modification shown in FIG. 7, the electrode portion 61 and the electrode mounting arm 62 are constructed as separate bodies and are detachable. If such a configuration is adopted, when the outer diameter dimension of the disk to be manufactured is changed, the electric field forming device 60 can be replaced simply by replacing the electrode portion 61, which is simple.

In the above-mentioned embodiment and each modification, the two objects to be bonded to each other are both the disk substrate 1.
Although it is configured by a plate-like object consisting of a and 1b, the present invention is not limited to the configurations of the embodiments and modified examples.
The two superposed objects do not necessarily have to be plate-shaped objects. For example, an object supported by the lift plate 20 and coated with the ultraviolet curable resin composition S (corresponding to the disk substrate 1a) is the first object, and an object supported by the receiving portion 23 (corresponding to the disk substrate 1b) is an object. In the case of the second object, the second object supported by the receiving portion 23 is not a plate-like object as long as the electric field formed by the electric field forming device can pass through and act on the ultraviolet curable resin composition S. May be. However, in order to facilitate the transmission of the electric field, it is preferable that the second object has at least a thin plate-shaped region through which the electric field is transmitted to act on the ultraviolet curable resin composition S. Further, since the first object to which the ultraviolet curable resin composition S is applied does not transmit an electric field, its shape and the like are arbitrary and are not limited to plate-like objects. In addition, it is preferable that the first object and the second object each have a flat surface on which the ultraviolet curable resin composition S is superposed.

[0054]

As described above, according to the present invention,
When two objects, for example, disk substrates and the like are superposed with an adhesive, an electric field is formed on the surface side different from the superposing surface of the other object, corresponding to the adhesive applied to one object, By allowing the electric field to pass through the other object and act on the adhesive, the initial contact area between the adhesive and the other object is reduced. Then, the contact area of the adhesive between both objects expands starting from this part, and the air existing between both objects is pushed out by the adhesive, so that air bubbles may be caught between the object and the adhesive. Absent. Moreover,
Both the first electrode and the second electrode forming the electric field forming means are arranged on one side of the two objects, and if the distance between the two electrodes is fixed, the magnitude of the electric field can be increased even when the two objects are brought close to each other. Does not change, so the discharge phenomenon does not occur.
As a result, it is possible to safely and effectively raise the adhesive and prevent air bubbles from entering between the bonded objects.

[Brief description of drawings]

FIG. 1 is a plan view showing a schematic configuration of a disk manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing a schematic configuration of a superposing device.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a plan view showing a schematic configuration of a flat surface holding device.

FIG. 5 is a plan view showing a schematic configuration of a plane holding unit,
FIG.

6A and 6B show an electric field forming device according to a first modification of the present invention, wherein FIG. 6A is a side view and FIG. 6B is a plan view seen from the substrate receiving portion side.

7A and 7B show an electric field forming apparatus according to a second modification, wherein FIG. 7A is a side view in a separated state, and FIG. 7B is a plan view similarly seen from the substrate receiving portion side.

[Explanation of symbols]

1 disc 1a disc substrate (one disc substrate) 1b Disc substrate (other disc substrate) 5 Coating device (coating means) S UV curable resin composition 6 UV irradiation device 7 Overlay device (overlap means) 8 Spreading device 21 Disk substrate holding device (holding means) 22 Reverse arm 23 Board receiving part 28, 60, 70 Electric field forming device (electric field forming means) 29 Plate-shaped electrode (first electrode) 30 linear electrode (second electrode) 31 voltage application device (voltage application means)

Claims (17)

[Claims] 1. A joining method for joining two objects using a liquid adhesive, the method comprising: applying an adhesive to one object; and another object with the adhesive sandwiched between the one object and the other object. Forming an electric field acting on the adhesive between the two objects by an electric field forming means installed on a surface side different from the overlapping surface of the other object at the time of overlapping. A method of joining objects characterized by. 2. The method for joining objects according to claim 1, wherein among the two objects, at least the other object is a plate-like object. 3. The method for joining objects according to claim 1, wherein the two objects are disk substrates. 4. The first electrode, wherein the electric field forming means is arranged on a surface side different from the overlapping surface of the other object,
The object bonding according to any one of claims 1 to 3, further comprising a second electrode arranged at a fixed position apart from the first electrode so as to form an unequal electric field between the two electrodes. Method. 5. The object joining method according to claim 4, wherein the first electrode is a plate-like electrode, and the second electrode is a linear electrode disposed closer to the object than the first electrode. Method. 6. The method for joining objects according to claim 1, wherein the adhesive is an ultraviolet curable resin composition. 7. The method for joining objects according to claim 3, wherein the adhesive is applied to a clamp area provided on an inner peripheral portion of the disc substrate in a concentric pattern with the disc substrate. . 8. A joining device for joining two objects using a liquid adhesive, comprising: an application means for applying the adhesive to one object; and another device with the one object sandwiching the adhesive. An object joining apparatus comprising: a superposing means for superposing objects, and an electric field forming means for forming an electric field acting on the adhesive on a surface side different from a superposing surface of the other object. 9. The object joining apparatus according to claim 8, wherein at least the other of the two objects is a plate-like object. 10. The electric field forming means comprises: a first electrode arranged on a surface side different from the overlapping surface of the other object; and a second electrode arranged at a fixed position separated from the first electrode. The object according to claim 8 or 9, further comprising: a voltage applying unit that applies a voltage between the both electrodes, wherein the second electrode is formed in accordance with a shape of an adhesive applied to the one object. Joining equipment. 11. The object joining apparatus according to claim 10, wherein the second electrode is a linear electrode and has a width of 0.5 mm or less. 12. A disk manufacturing apparatus for bonding two disk substrates using a liquid adhesive to form one disk, and an applying means for applying the adhesive to one of the disk substrates. A superposing means for superposing the other disc substrate while sandwiching the adhesive on the disc substrate, and a surface side different from the superposing surface of the other plate-like object,
An electric field forming means for forming an electric field corresponding to the adhesive applied to the one plate-like object, the disk manufacturing apparatus. 13. The stacking means is provided with a holding means for holding the other disk substrate on a surface different from the stacking surface, and the holding means is provided with the electric field forming means. The disk manufacturing apparatus according to claim 12. 14. The disk manufacturing apparatus according to claim 12, wherein the electric field forming means is replaceable with a device having a different electric field forming position. 15. The electric field forming means comprises a plate electrode and a linear electrode arranged at a fixed position apart from the plate electrode.
15. A voltage applying means for applying a voltage between the both electrodes, wherein the linear electrode is formed in conformity with an application shape of an adhesive applied to the one disk substrate. The described disk manufacturing apparatus. 16. The disk manufacturing apparatus according to claim 15, wherein the width of the linear electrode is 0.5 mm or less. 17. The application means is provided to apply the adhesive in a concentric circle with the disc substrate to a clamp area provided on an inner peripheral portion of the disc substrate. Disc manufacturing equipment.