JP3362016B2 - Optical disc bonding apparatus and method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminating apparatus for laminating an optical disk substrate having an information recording layer having a conductive thin film as a reflective layer with an adhesive to make one optical disk.

[0002]

2. Description of the Related Art Disc bonding will be described as a conventional example. In an optical disc laminating apparatus using a liquid adhesive, it is necessary to prevent voids (air bubbles) in the adhesive layer after laminating. Is important, and various methods have been considered for that purpose. However, all methods are voids or diameters with a diameter of about 0.1 mm or more.
Minute voids of 0.05 mm to 0.1 mm or less or mixed voids are formed between the disk substrates.

As a method capable of considerably improving such a conventional method, the present applicant has filed a patent application for the following invention (Japanese Patent Application No. 10-257530). The invention of this application will be described with reference to FIG.

Of the two disk substrates A and B, the adhesive surface of the lower disk substrate A is faced up, and the annular adhesive liquid film a is formed there. On the bonding surface of the upper disk substrate B, a plurality of dot-shaped adhesive liquid films b are formed on a virtual circle having a diameter slightly larger than or similar to the diameter of the annular adhesive liquid film a. After that, the two disc substrates A and B are brought close to each other with their adhesive surfaces facing each other, and the annular adhesive liquid film a and the dot-shaped adhesive liquid film b are brought into contact with each other to make two disc substrates A. , B on top of each other. Next, two disk substrates A and B
Is spin-treated to spread the adhesive liquid film a and the adhesive liquid film b, and the excess adhesive is shaken off to form an adhesive layer having a uniform film thickness between the disk substrates A and B.

That is, on the outside of the annular adhesive liquid film a on the surface of the lower disk substrate A, the upper disk substrate B is placed.
By appropriately contacting the tops of the dot-shaped adhesive liquid films b on a virtual circle on the surface, it is possible to prevent the occurrence of voids, particularly minute voids, which occur at the moment when these liquid films contact each other, and When the contact portion spreads over the entire liquid film, air between the liquid films can be eliminated, so that the occurrence of voids at this time is reduced.

[0006]

However, even with such a method, it is extremely difficult to sufficiently reduce the contact area at the moment when the adhesive liquid film a and the adhesive liquid film b contact each other. You can't eliminate all such voids.

Accordingly, the present invention provides an optical disk substrate bonding apparatus and method in which, when two disk substrates are bonded together with an adhesive, virtually no voids are generated or hardly generated between them. It is an issue.

[0008]

In order to solve the above-mentioned problems, the invention of claim 1 is an optical disk bonding apparatus for manufacturing one optical disk by bonding optical disk substrates with an adhesive, An electric field forming device for forming an electric field in a space between the optical disk substrate and the electric field is formed in the space between the optical disk substrates, and the electrostatic attraction due to the electric field causes the top portion of the liquid film of the adhesive to move. The present invention provides an optical disk laminating apparatus characterized by tapering to reduce a contact area and preventing bubbles from existing between the two optical disk substrates.

In order to solve the above-mentioned problems, the invention of claim 2 provides an adhesive agent to at least one of the optical disk substrates, and the adhesive agent is sandwiched between the optical disk substrate and the other optical disk substrate so as to be bonded together. In an optical disk laminating apparatus for manufacturing an optical disk, at least a part of a surface, which is a means for supporting each of the optical disk substrates and abutting opposite surfaces corresponding to the adhesive-supplied surfaces of the optical disk substrate, from electrodes. becomes, and a pair of electrodes and support means the electrodes are each flat, a voltage is applied between the electrodes of the electrode-and-bearing means, by forming an electric field in the space between the optical disc substrate, that Adhesion by electrostatic attraction by electric field
The top of the liquid film of the agent is tapered to reduce the contact area,
Prevent bubbles from existing between the two optical disk substrates
The present invention provides an optical disk laminating apparatus, which is provided with:

In order to solve the above-mentioned problems, the invention of claim 3 relates to the invention of claim 2, wherein, of the pair of electrode / bearing means, one of the electrodes on the side to which a voltage is applied by the power source is the reflection. An optical disk laminating apparatus, which is substantially the same as the reflecting film in order to reduce the stray capacitance between the film and the ground.

In order to solve the above problems, in the invention of claim 4, an adhesive is applied to at least one of the optical disk substrates, and the adhesive is sandwiched between the other optical disk substrate and the other optical disk substrate so as to adhere to each other. In an optical disk laminating method for manufacturing an optical disk, an electric field is formed in a space between the optical disk substrate and the optical disk substrate before being superposed, and the top of the liquid film of the adhesive is tapered by electrostatic attraction due to the electric field. A method for laminating optical discs, characterized in that the contact area is made smaller to prevent air bubbles from existing between the two optical disc substrates.

In order to solve the above problems, in the invention of claim 5, an adhesive is applied to at least one of the optical disk substrates, and the adhesive is sandwiched between the other optical disk substrate and the other optical disk substrate so as to be bonded together. In an optical disk laminating method for manufacturing an optical disk, a predetermined voltage is applied by each electrode corresponding to each optical disk substrate to form an electric field in a space between the optical disk substrates.
And a step of bringing them into proximity with each other while applying a predetermined voltage between the optical disk substrates, and electrostatically attracting them by the electric field.
The contact area is made by tapering the top of the liquid film of the adhesive with force.
To bring the adhesive into contact with the liquid, a step of removing the predetermined voltage between the optical disk substrates to reduce it to a low voltage, and a step of separating the electrodes from each other,
And a bubble exists between the two optical disk substrates.
An optical disk laminating method characterized by preventing

In order to solve the above-mentioned problems, the invention of claim 6 relates to claim 4 or claim 5, wherein the electric field is
A method for laminating optical disks, wherein electric charges having positive and negative polarities are induced on the two optical disk substrates.

In order to solve the above-mentioned problems, the invention of claim 7 is the invention of claim 4 or claim 5, wherein the electric field is
A method for laminating optical disks, wherein electric charges are induced in the adhesive and the electric charges of the adhesive are neutralized when they come into contact with each other.

[0015]

First, the principle of the present invention will be described. The present invention is based on the finding that when the liquid film of the adhesive formed on the upper and lower optical disk substrates first comes into contact, the smaller the contact area, the more difficult it is to form minute voids. By forming it in the space between them, the top of the liquid film of the adhesive is tapered by the attractive force of the electric field, and the initial contact area is made sufficiently small.

Further, by applying positive and negative charges having different polarities to the upper and lower discs and the liquid film by the electric field, the liquid film and the optical disc resulting from the combination of the positive and negative charges when the liquid films come into contact with each other. The spreadability between the substrate and the substrate is improved and the generation of voids is further suppressed.

As a generally known digital versatile disc (DVD), a single-sided single-layer type optical disc having a recording layer including a pit row and a reflective layer only on one optical disc substrate to be laminated, both laminated Double-sided single-layer type optical disc having a recording layer on the optical disc substrate, or one-sided two with one reflecting layer made of a semitransparent film
There is a layered optical disc or a double-sided dual-layered optical disc in which two single-sided dual-layered optical discs are stuck together, and the present invention can be applied to the production of these various types of DVDs.

An embodiment according to the present invention will be described below with reference to the drawings. In this embodiment, the voltage applied between the optical disk substrates via the electrodes is effectively applied between the reflection films, and the sticking is performed so that no discharge occurs between the electrodes when the optical disk substrates approach each other. This is to specify a matching method and electrodes.

As shown in FIG. 1, the lower optical disk substrate A is placed on the electrode 1 of the electrode / bearing means which also functions as a pedestal, and the upper optical disk substrate B is the electrode 2 of the electrode / bearing means. Supported by. Optical disk substrate A,
Each B has a normal recording layer (not shown) on one surface, and reflective films A ′ and B ′ formed thereon. These reflective films
Optical disk substrate A so that A'and B'face each other with a gap.
, B are supported by the electrodes 1 and 2 of the electrode / bearing means. The optical disk substrates A and B respectively have central holes X and Y having substantially the same diameter, and the reflective films A ′ and B ′ generally have central holes X and
It has an inner diameter larger than Y and also has an optical disc substrate A.
, B has a smaller outer shape than that of B.

In FIG. 1, only those electrodes 1 and 2 are shown as the electrode / bearing means. The electrodes 1 and 2 of the electrode / bearing means have the same shape and the same size, and their optical disk substrates A, The surface in contact with B has a smooth flat plate shape. Although not shown in FIG. 1, the electrodes 1 and 2 of the electrode / bearing means have ordinary suction holes for sucking and holding the optical disk substrates A and B, respectively, and the plurality of suction holes are not shown in the drawing. Be combined with. The electrodes 1 and 2 of the electrode / bearing means have an inner diameter that is about the diameter of the central holes X 1 and Y 2 of the optical disk substrates A 1 and B 2 or that is larger than that, and about the outer diameter of the reflecting films A ′ and B ′, or more Also has a small outer diameter.

When the electrodes 1 and 2 of the electrode / bearing means have a size outside this region, a discharge is likely to occur between the electrodes 1 and 2 of the electrode / bearing means when they come closest to each other, as described later. Therefore, it is not preferable. Even if the electrodes 1 and 2 of the electrode / bearing means are in the above-mentioned area, if the area is significantly smaller than the areas of the reflection films A ′ and B ′, the stray between the reflection film A ′ and the ground, which will be described later, will be described. A capacitance is increased, and a reflection film for a voltage applied between the electrodes 1 and 2 of the electrode / bearing means
There is a problem that the voltage between A'and B'is considerably small. Therefore, preferably, as shown in FIG. 3, the electrodes 1 and 2 of the electrode / bearing means have an inner diameter substantially equal to the inner diameters of the reflection films A ′ and B ′, and substantially equal to the outer diameters of the reflection films A ′ and B ′. It is preferable to have an outer diameter, that is, a shape congruent with the reflection films A ′ and B ′.

The electrode 1 of the electrode / bearing means is selectively connected to the DC power source 4 or the ground via the switch 3, and the electrode 2 of the electrode / bearing means is fixed to the ground. Therefore, when the DC output voltage of the DC power source 4 is set to V and the switch 3 is closed to the contact 3a side, the voltage V is applied via the switch 3 between the electrodes 1 and 2 of the electrode / bearing means. Here, the electrode 1 serving as the electrode / bearing means, the reflecting film A ′, and the insulating material of the optical disk substrate A form a capacitance C1. Reflective film A'and B '
And the air gap between them forms a variable capacitance C2. Further, the reflective film B ', the electrode 2 of the electrode / bearing means and the insulating material of the optical disk substrate B sandwiched therebetween form a capacitance C3. These capacitances C1 to C3 are connected in series as shown in FIG.

However, in practice, as shown in FIG. 1, there is a stray capacitance that greatly affects the voltage applied to these capacitances C1 to C3, that is, the sharing of the voltage. As this stray capacitance, there is a stray capacitance SC which is connected between the reflection film A ′ to which a voltage is applied and the ground, which is connected as shown in FIG. This stray capacitance SC is the capacitance of the stray capacitance SC due to the connection relationship with each capacitance.
The larger the capacitance value of C2 and C3 in series, the greater the proportion of the capacitance C1 that shares the power supply voltage V. As a result, the voltage applied to the capacitances C2 and C3 decreases, and the capacitance C3 is constant, so the voltage applied to the capacitance C2 decreases.
This indicates that the voltage between the reflection films A ′ and B ′ becomes small.

That is, as the stray capacitance SC becomes smaller than the capacitance C1, the reflective film
The ratio of the power supply voltage V applied between A'and B'is increased.
Further, the larger the capacitances C1 and C3, the larger the voltage applied to the capacitance C2. Therefore, FIG.
As shown in FIG.
Stray capacitance when almost equal to A '
Since SC becomes extremely small, that is, it becomes extremely small compared to the capacitance value of the capacitances C2 and C3 in series, and becomes negligible, the ratio of the power source voltage V applied to the capacitance C2 becomes the largest.

The stray capacitance formed between the reflective film B ′ and the ground acts in the direction of increasing the voltage sharing, but since its value is difficult to determine in design, it is ignored. Therefore, here, the electrode 2 of the electrode / bearing means is used.
The shape and size of the
It may be smaller than.

Although it has been described that the electrode 1 of the electrode / bearing means and the reflecting film A ′ should come close together, in reality, the electrode 1 of the electrode / bearing means on the voltage applying side is reflected due to the relation of the transport mechanism. It may not always be a good idea to make the outer diameter substantially equal to the outer diameter of the film A ′ due to the mechanism or the like, and in this case, there is no choice but to make it smaller than the outer diameter of the reflective film A ′ by a certain width. It is preferable to use a flat plate-shaped one such as a needle-shaped or rod-shaped one having a small tip portion area because it can reduce the stray capacitance SC described above. It is preferable that it is a ring-shaped flat plate that is as large as possible except for. Here, the flat plate includes not only a relatively thick flat plate but also a metal thin film formed on an insulating plate or the like.

The reflective films A ′ and B ′ of the disk substrates A and B
As shown in FIG. 4, liquid films a 1 and b 2 of an adhesive are provided on the top of each. A continuous annular liquid film a is formed on the lower optical disc substrate A, and a discontinuous liquid film b is formed on the upper optical disc substrate B at substantially regular intervals in a virtual circle indicated by a chain line b ′.
Is formed. Here, the diameter of the center of the continuous annular liquid film a of the lower optical disc substrate A is D, and the diameter of the virtual circle shown by the chain line b ′ of the upper optical disc substrate B is D, which are equal to each other. .

Next, with reference to FIGS. 5 to 8, a description will be given of an embodiment in which optical disks are bonded by a voltage application method. The electrode 1 of the electrode / bearing means which also functions as a pedestal is fixed to a center shaft 5 projecting at the center thereof. A side wall of the center shaft 5 is divided into a plurality of pieces so that the chuck claws, which will be described later, can be passed through when the expansion and contraction operations are performed. The electrode 1 of the electrode / bearing means is fixed to an elevating shaft 6 coaxial with the center shaft 5, and although not shown, as the elevating shaft 6 is moved up and down by a driving device, the electrode 1 of the electrode / bearing means is Also moves up and down, for example, an optical disk substrate A placed on each window of the turntable
In the process of ascending, the electrode 1 of the electrode / bearing means receives and ascends to the position shown.

The electrode 1 is selectively connected to the negative terminal of the DC power source 4 by the switch 30 and the conductor 7. The positive terminal of the DC power source 4 is grounded. The voltage value of the DC power supply 4 causes the tip portions of the liquid film a and the liquid film b of the adhesive to be deformed into a tapered shape immediately before they come into contact with each other.
The value is set to a value that is equal to or higher than the voltage at which the wettability of the liquid film a and the liquid film b of the adhesive is improved and spreads, and is equal to or lower than the voltage at which discharge does not occur between the electrode / bearing means.

The flat plate-shaped electrode 2 of the electrode / supporting means that supports the upper optical disk substrate B is equipped with a general suction tool (not shown), and the suction operation is performed by the suction tool.
Adsorb and hold the upper surface of B. Electrode 2 of electrode and bearing means
Is connected to a transfer arm that can swivel horizontally at an angle (not shown), and is grounded through the transfer arm or the like.

The electrode 2 of the electrode / bearing means is fixed at its center to the chuck means 8 having an axis centered with the axis of the center shaft 5 of the lower electrode / bearing means. Chuck means 8
Has three chuck claws 9 which are operated by an external signal and perform expansion / contraction diameter operation. The chuck claw 9 expands the optical disk substrates A and B in the central hole X of the optical disk substrates A and B before transferring them to another place while holding the stacked state. It supports the inner walls of A and B, and its operation will be described in detail later.

Next, the bonding will be described while explaining the operation of this mechanism. At least the upper optical disk substrate B is attracted to and held by the electrode 2 of the electrode / bearing means, and at another position, as shown in FIG. Is formed. The optical disk substrate A on the lower side is the electrode 1 of the electrode and supporting means.
A continuous annular liquid film a is formed on the upper surface in a state of being placed on the upper surface. Figure 4 shows the positional relationship between liquid film a and liquid film b.
become that way. Next, the transfer arm (not shown) connected to the electrode 2 of the electrode / bearing means performs a pivotal movement to convey the electrode 2 of the electrode / bearing means to the position shown in FIG. 5 and stop it.

Next, as shown in FIG. 6, the lifting shaft 6
By raising the electrode 1 of the electrode / bearing means, the electrode 1 of the electrode / bearing means and the electrode 2 of the electrode / bearing means start to approach each other, and a certain distance (for example, about 20 mm)
When it comes close to, the voltage V of the DC power supply 4 is applied between the electrodes 1 and 2 by closing the switch 3 to the contact 3a. Accordingly, as described above, the optical disc substrates A and B are
A voltage having a certain ratio of the voltage V 2 is applied between the reflective films A ′ and B ′. Therefore, an electric field is formed in the space between the reflective films A ′ and B ′.

By applying the voltage, the liquid film a of the adhesive a
The liquid film b and the liquid film b have opposite charges, and when they attract each other, the top of the liquid film a and the tip of the liquid film b tend to taper. Then, as the space between the optical disk substrates A and B narrows, the electric field in that space increases, and the liquid film a
When liquid comes into contact with liquid film b, the attractive force due to the electric field is maximized, and the top of liquid film a and the tip of liquid film b are further tapered,
Since the top of the tapered liquid film a and the tip of the liquid film b first come into contact with each other, the area at the moment of contact between the liquid film a and the liquid film b is significantly smaller than in the conventional case.

The state after this contact is shown in FIG. When the top of liquid film a and the tip of liquid film b contact, the negative and positive charges of liquid film a and liquid film b are neutralized to improve wettability, resulting in discontinuous liquid film b. Rapidly spreads in an elliptical shape along a continuous liquid film a, and liquid film a and liquid film b together form an annular liquid film, and positive and negative charges remain on the surface. It spreads between the optical disk substrates A and B in the radial direction.

Next, the chuck means 8 is operated by an external signal, and the chuck claws 9 of the chuck means 8 move in the central holes of the optical disk substrates A and B.
The diameter expansion operation is performed at X, and the inner walls of the optical disk substrates A and B are pressed and held as shown in FIG. Then, the switch 3 is switched to the contact 3b to cut off the power supply voltage, and at the same time, the electrode 1 is connected to the ground voltage, and after the voltage between the electrode 1 and the electrode 2 becomes almost zero, the elevating shaft 6 descends. And lower the electrode 1 of the electrode and bearing means,
The optical disk substrates A and B are held by chuck means 8 and supported on the electrode 2 side of the electrode / supporting means. As described above, since the electrode 1 is moved away from the electrode 2 after the voltage between the electrode 1 and the electrode 2 is almost zero, a discharge may occur between the electrodes and damage the optical disk substrates A and B. There is also no.
Here, since the voltage of the capacitance C2 between the reflection films A'and B'of the optical disk substrates A and B decreases and becomes zero due to the discharge due to the liquid contact, the voltage is not a problem, but the capacitance C2
It is necessary to reduce the voltage of electrode 1 to almost zero in order to discharge C1 and C3.

Actually, in this state,
The liquid film of the adhesive between B and B spreads inward and outward from the drawing, and as a result of observing through the optical disk substrates A and B, minute voids and larger voids were not visible. After that, the electrode 2 of the electrode / bearing means is replaced with the optical disk substrate A.
The optical disk substrates A and B are transferred together with B to a spinner device (not shown) by a rotating means (not shown), and the centrifugal force produces a uniform film thickness.
Unnecessary adhesive is shaken off. Of course, both disks may be spin-treated at the position where they come into contact with the liquid.

According to this embodiment, the top of the liquid film a and the tip of the dot-shaped liquid film b taper due to the electric field, and the adhesive comes into contact with the tips of the liquid film a. Occurrence of minute voids that are easily formed is suppressed. Further, in order to improve the wettability, the discontinuous liquid film b rapidly becomes an ellipse and spreads along the annular continuous liquid film a without generating voids, and at the same time, the liquid films a and b Does not engulf air in this process because it spreads between the optical disk substrates A and B whose surfaces are positively and negatively charged in the outward radial direction.
It was confirmed that in the adhesive layer spread uniformly between A and B, the generation of micro voids and large voids with a larger diameter than that can be significantly suppressed.

In this embodiment, it is assumed that the diameter of the center of the continuous annular liquid film a of the lower optical disk substrate A and the diameter of the virtual circle shown by the chain line b ′ of the upper optical disk substrate B are equal to each other. As described above, the diameter of either one may be somewhat larger, and the effect of the present invention can be obtained even if the liquid film is formed only on one of the optical disk substrates. Further, even if the adhesives are discontinuously formed on both optical disk substrates in a dotted line shape, the effect of the present invention can be similarly obtained if the distance between the liquid films adjacent to each other is relatively small. Furthermore, in the above-described embodiment, the electrodes of both electrode / bearing means have the same shape and the same size, but they do not have to be the same, and the ground side electrode may be small.

In the example embodiment of FIGS. 5-8, the electrode 1
Although the disk substrate A is placed on the upper electrode by dividing it into two parts, the lower electrode is connected to the elevating shaft 6 and moves up and down together. , For example, if the upper disk located on the transport turntable is raised together with the disk substrate A, or if the upper disk is returned to the turntable, the upper electrode can be transferred onto the optical disk without bearing on the transport. It can be combined with the reflective film A ′ of the substrate A. By doing so, the stray capacitance between the electrode 1 and the ground can be greatly reduced.

Further, in the above embodiment, the switch 3 is used for the sake of easy understanding of the description.
A controllable power supply capable of supplying a DC output voltage having a desired pulse width without using a power supply, and a capacitor or a capacitor on the output side of the power supply during a period in which the power supply does not substantially output the DC output voltage. A circuit configuration in which the electrode 1 is connected to the ground potential by a resistor may be used.

[0042]

As described above, according to the present invention, when the optical disk substrates are bonded together, a planar electric field is formed in the space between the reflective films before they are stacked, and the adhesives facing each other are contacted with each other. Since the planar electric field is applied, the liquid contact is performed in a state where the adhesive is very preferable, and it is possible to significantly suppress the formation of voids between the bonded objects.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an optical disk laminating apparatus according to the present invention.

FIG. 2 is a diagram for explaining a relationship of capacitance in the optical disk bonding apparatus according to the present invention.

FIG. 3 is a diagram for explaining an optical disk laminating apparatus according to the present invention.

FIG. 4 is a diagram for explaining an optical disk laminating apparatus according to the present invention.

FIG. 5 is a diagram for explaining an example of an embodiment of an optical disk laminating apparatus according to the present invention.

FIG. 6 is a diagram for explaining an embodiment of an optical disk laminating apparatus according to the present invention.

FIG. 7 is a diagram for explaining an example of an embodiment of an optical disk laminating apparatus according to the present invention.

FIG. 8 is a diagram for explaining an example of an embodiment of an optical disk laminating apparatus according to the present invention.

FIG. 9 is a diagram for explaining a conventional optical disc bonding method.

[Explanation of symbols]

1, 2 ... Electrodes serving as electrodes and supporting means 3 ... switch 4 ... DC power supply 5 ... Center shaft of lower electrode and bearing means 6 ... Lifting shaft 8: chuck means A, B ・ ・ ・ Optical disk substrate A ', B' ... Reflective film on optical disk substrates A and B a, b ... Adhesive liquid film

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Kotoyori 1-18-1 Takada, Toshima-ku, Tokyo Within Ordin Electric Co., Ltd. (56) Reference JP 9-293282 (JP, A) JP JP 10-312591 (JP, A) JP-A-7-228847 (JP, A) JP-2000-290602 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B 7/26 B29C 65/00

Claims (7)

(57) [Claims] 1. An optical disk bonding apparatus for manufacturing an optical disk by bonding optical disk substrates with an adhesive, comprising an electric field forming device for forming an electric field in a space between the optical disk substrates. By forming the electric field in the space between the optical disk substrates, the electrostatic attraction due to the electric field causes the top of the liquid film of the adhesive to be tapered to reduce the contact area, and to form a bubble between the two optical disk substrates. An optical disk laminating apparatus characterized by preventing the existence of the above. 2. An optical disk bonding apparatus for manufacturing one optical disk by applying an adhesive to at least one optical disk substrate and bonding the adhesive to the other optical disk substrate, wherein the optical disk substrate Means for supporting each of the
At least a part of the surfaces of the optical disk substrate, which are in contact with the opposite surfaces corresponding to the adhesive-supplied surfaces, are made of electrodes, and the electrodes have a flat plate shape. Applying a voltage between the electrodes of the support means,
In particular to form an electric field in the space between the optical disc substrate
The electrostatic attraction of the electric field causes the top of the liquid film of the adhesive.
Taper to reduce the contact area,
An optical disk laminating apparatus comprising: a power supply for preventing bubbles from existing between the disc substrates . 3. The reflecting electrode according to claim 2, wherein one of the pair of electrodes and bearing means on one side to which a voltage is applied by the power source reduces the stray capacitance between the reflection film and the ground. An optical disk laminating apparatus, which is almost congruent with a film. 4. An optical disk bonding method for manufacturing one optical disk by applying an adhesive to at least one optical disk substrate and bonding the adhesive to the other optical disk substrate before the superposition. By forming an electric field in the space between the optical disk substrate and the optical disk substrate ,
A method of laminating optical disks, characterized in that the contact area is reduced by tapering the top of the liquid film of the adhesive by the electrostatic attraction to prevent air bubbles from existing between the two optical disk substrates. 5. An optical disk bonding method for producing one optical disk by applying an adhesive to at least one optical disk substrate and bonding the adhesive to the other optical disk substrate, wherein A predetermined voltage is applied to each of the electrodes corresponding to the optical disk substrates,
A step of forming an electric field in the space, and bringing them close to each other while applying a predetermined voltage between the optical disk substrates , and adhering them by electrostatic attraction by the electric field.
Tapering the top of the liquid film of the agent to reduce the contact area and bringing the adhesive into contact with the adhesive, and removing the predetermined voltage between the optical disk substrates to reduce it to a low voltage And a step of separating the electrodes from each other , wherein bubbles are present between the two optical disk substrates.
A method for laminating optical disks, which is characterized by preventing 6. The optical disk bonding method according to claim 4, wherein the electric field induces charges of positive and negative opposite polarities on the two optical disk substrates. 7. The optical disk laminating method according to claim 4, wherein the electric field induces electric charges in the adhesive, and the electric charges of the adhesive are neutralized when they come into contact with each other. .