JP2002025127A - Method and device for chucking, and method for manufacturing falt plate body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for chucking, capable of surely chucking a relatively thin and low-rigid flat plate body such as the substrate of an optical disk or the like without any deformation even when it is sucked by a negative pressure, and a method for manufacturing the flat plate body. SOLUTION: This chucking method holds the flat plate body to a fixed surface by disposing the flat plate body in a fixed surface 23 having rigidity, and sucking a surface to be sucked from a number of suction holes 24, 25, 26 opened in the fixed surface. The area of one of the suction holes is converted into a circle, and the diameter of the converted circle is set equal to/lower than the thickness of the flat plate body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chucking method for chucking a flat plate such as an optical disk at the time of manufacturing, etc., a chucking device, and a manufacturing method for bonding and manufacturing a flat plate.

[0002]

2. Description of the Related Art For example, an optical disk represented by a DVD (Digital Versatile Disk), which is formed by bonding two resin light-transmitting substrates each having a thickness of about 0.6 mm, has been put to practical use. . In producing such an optical disc, a resin (mainly a polycarbonate resin or a polyolefin resin) having a thickness of about 0.6 mm is used.
After forming a recording layer and a protective layer on the disc-shaped light-transmitting substrate described above, these two disc-shaped substrates are bonded together.

Various methods are applied to this bonding method depending on the adhesive to be used. In any case, the disk-shaped substrate must be fixed to the work table. Although this fixing method differs depending on the bonding method to be applied, a method called suction using mainly suction force by negative pressure air is used.

[0004] Suction using the suction force of negative pressure air is used not only at the time of bonding but also in various situations such as a manufacturing apparatus using a spin coating method for applying an adhesive and a drive apparatus for recording / reproducing. In general, a method is employed in which a portion other than the information area on the light incident surface of the optical disk, that is, only the inner peripheral chucking portion of the disk is sucked. However, since this suction method has a small suction force, a suction method over the entire disk surface has been proposed as a method for more firmly chucking (sucking) (for example, see Japanese Patent Application Laid-Open No. 9-306070).

Here, the suction force can be increased by increasing the suction force of the negative pressure air. However, as described above, DVDs have a relatively low rigidity because the light-transmitting substrate is as thin as 0.6 mm and is made of resin. When such a light-transmitting substrate is used, it is necessary that the substrate be sucked by a weak suction force corresponding to its rigidity so as not to be deformed by suction (to maintain a flat surface).

[0006]

However, chucking with a weak suction force is not preferable in terms of workability and safety. Particularly, when a screen printing method is used as an adhesive application method for bonding, etc. When the adhesive is applied to the disk surface of the sucked disk substrate by screen printing, the adhesive applied to the disk surface comes into close contact with the screen (plate), and the disk substrate moves together with the plate. Sometimes. In order to prevent this, it is necessary to suction strongly. However, as described above, since the light-transmitting substrate has relatively low rigidity, the following problem occurs. That is,
As shown in FIG. 4, the disk-shaped substrate 50 is
When the suction is performed more strongly by 52, a difference occurs in the load of the force between the sucked portion 50a and the non-sucked portion 50b, so that the disk-shaped substrate 50 is locally deformed. This deformed portion becomes a concave portion 50c by suction, and the concave portion 50c
May be applied with a smaller amount of adhesive compared to other portions, or conversely, the recess 50c may be applied depending on other adhesive application methods.
As a result, a large amount of adhesive was applied to the adhesive, and the adhesive could not be applied satisfactorily, causing uneven application. For this reason, when an optical disk is manufactured by bonding two disk-shaped substrates together, mechanical accuracy such as surface runout acceleration has deteriorated.

In view of the above-mentioned problems of the prior art, the present invention reliably chucks a relatively thin and rigid plate-like body such as a substrate of an optical disk or the like without being deformed even when sucked by negative pressure. It is an object of the present invention to provide a chucking method and a chucking device that can be king.
Further, a flat plate which can prevent uneven application of the adhesive when one flat plate is manufactured by bonding two flat plates by applying an adhesive in a state of being sucked by a negative pressure. It is intended to provide a method for producing a body.

[0008]

Means for Solving the Problems The present inventor has made intensive studies to achieve the above object, and as a result, has found that the size of a large number of suction holes provided on a fixing surface to which a plate-like body such as an optical disc substrate is fixed is fixed. It has been found that the above problem can be solved by appropriately setting the thickness in relation to the thickness of the plate-shaped body to be sucked, and the present invention has been accomplished.

That is, the chucking method according to the present invention comprises:
A chucking method of arranging a flat plate on a fixed surface and chucking the flat plate with respect to the fixed surface by sucking the suctioned surface from a number of suction holes opened in the fixed surface, The fixing surface has rigidity, and the area of one suction hole is converted into a circle, and the diameter of the converted circle is equal to or less than the thickness of the flat plate.

According to this chucking method, the area of each suction hole is determined such that the diameter of a circle converted from the area of one suction hole is equal to or less than the thickness of the flat plate to be sucked. Even when the body is relatively thin and low in rigidity, suction is performed appropriately without deformation, and the fixed surface is rigid and hard to deform, so that the flat body can be reliably chucked to the fixed surface. .

Here, the area of the suction hole means the area of the suction hole opened on the fixed surface. In addition, that the fixing surface has rigidity means that the surface has a hardness equal to or higher than that of the flat body, and has a relatively soft shock absorbing member made of a cushion material or the like. No state means. Also, since the diameter of the circle converted from the area of one suction hole is set to be equal to or less than the thickness of the flat body to be sucked,
The negative pressure generated in the suction hole on the fixed surface is not particularly limited and can be appropriately selected.

[0012] In this case, the flat plate is measured by the measuring method AST.
Flexural strength by MD790 is 8000-12000N /
cm ² is preferable from the viewpoint of achieving the effect of the present chucking method.

Further, the chucking device according to the present invention comprises:
A rigid surface on which a flat body is disposed, and a number of suction holes opened in the fixed surface for sucking a suction surface of the flat body and chucking the flat body against the fixed surface. Wherein the area of one suction hole is converted into a circle, and the diameter of the converted circle is equal to or less than the thickness of the flat plate.

According to this chucking device, the flat plate is deformed by making the diameter of the circle calculated from the area of one of the plurality of suction holes not more than the thickness of the flat plate to be sucked. Since the fixing surface is rigid and hardly deformed, the flat body can be reliably chucked to the fixing surface.

[0015] In this case, the flat body is measured by the ASTM measuring method.
Flexural strength according to D790 is 8000-12000N / c
m ² is preferable from the viewpoint of achieving the effect of the present chucking device.

Further, the method of manufacturing a flat plate according to the present invention is a method of manufacturing one flat plate by bonding two flat plates together, wherein the first flat plate is fixed to a fixed surface. And chucking the first flat plate with respect to the fixed surface by sucking the suction surface of the first flat plate through the plurality of suction holes by the chucking method described above. A step of applying an adhesive to an adhesive surface of the first flat plate opposite to the suctioned surface, and a step of applying an adhesive to the first flat plate and the second flat plate. And a step of bonding together.

According to this method for manufacturing a flat plate, the first flat plate can be reliably chucked without being deformed with respect to the fixed surface. Coating unevenness becomes difficult. Therefore, by bonding the second flat plate to the bonding surface of the second flat plate, a flat plate having good bonding quality can be manufactured.

In this case, it is also possible to apply an adhesive to the opposite adhesive surface of the second flat plate-like member while sucking the surface to be sucked and chucking the fixed surface in the same process as described above. preferable.

The first and second flat bodies are disk-shaped light-transmitting substrates, and the two light-transmitting substrates can be bonded together with an adhesive to manufacture an optical disk. According to this manufacturing method, uneven application of the adhesive is hardly performed on the two light-transmitting substrates. Therefore, the surface vibration acceleration and the like of an optical disc manufactured by bonding the two light-transmitting substrates with the adhesive are reduced. The machine accuracy becomes stable and good.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view schematically showing a main part of a chucking device according to an embodiment of the present invention, and FIG. 2 is a plan view of a fixing surface of FIG.

A chucking device 21 shown in FIG. 1 includes a fixing base 22 made of stainless steel or the like, a fixing surface 23 provided in the fixing base 22 in a circular shape, and a circular fixing surface 23.
Suction holes 24, 25, 26 formed by opening into
And suction through the communication holes 27 communicating with the suction holes 24, 25, and 26, and the suction holes 24, 2 on the fixed surface 23.
5, a suction pump 28 for generating a negative pressure.

As shown in FIG. 2, a large number of suction holes 29 are formed in the surface of the circular fixed surface 23 in FIG. Since each suction hole 29 may not be circular, the diameter of the circle converted from one area thereof is set to 0.5 mm. In addition, since the fixing base 22 is made of stainless steel or the like, and a cushioning material or the like is not attached to the fixing surface 23, the fixing surface 23 has sufficient rigidity with respect to a disk 30 to be chucked as described later. The distribution of the large number of suction holes 29 on the fixed surface 23 is not limited to the case as shown in FIG. 2, but may be another distribution form or a random distribution.

Next, the operation and effects of the chucking device 21 shown in FIGS. 1 and 2 will be described with reference to FIG. The disk-shaped body 30 as a flat body to be chucked is placed on the concave circular fixed surface 23 on the fixed base 22. The disk 30 is made of a thermoplastic resin having a bending strength of 8000 to 12000 N / cm ² according to the measurement method ASTM D790, and has a thickness t of 0.6 mm.

Next, by operating the suction pump 28 shown in FIG. 1, a large number of suction holes 24, 2 are formed through the communication holes 27.
Suction is performed through suction holes 5 and 26 (suction holes 29 in FIG. 2), and the suction surface 30a of the disc 30 is sucked and fixed to the fixed surface 23 by the negative pressure. At this time, each suction hole 24,
The area of 25, 26 (suction hole 29 in FIG. 2) is 0.5 mm as the diameter of the circle when converted into a circle, and the diameter is larger than the thickness 0.6 mm of the disk 30 to be sucked. Since it is small, the disk 30 hardly deforms as shown in FIG. 3, as compared with the case where the diameter of the suction hole is relatively large as in the conventional example of FIG. As described above, since a relatively thin disk-shaped body is appropriately sucked without being deformed and the fixing surface 23 is not deformed, the disk-shaped body can be reliably chucked to the fixing surface 23.

Also, the disk-shaped body 30 can be measured by the measuring method AST.
Flexural strength by MD790 is 8000-12000N /
If the material is relatively low in rigidity such as cm ² , it has been difficult to deform the chucking in the past and it was difficult to surely adsorb the material, but in the chucking device 21 of FIG. Even in this case, the effects of deformation prevention and reliable chucking can be obtained.

Next, an example in which the above-described chucking device is applied to a method of manufacturing an optical disk by bonding an adhesive will be described with reference to FIGS. 5, 6, and 7. FIG. FIG.
FIG. 6 is a cross-sectional view of the optical disk substrate before bonding in which each layer is formed. FIG. 6 is a diagram showing a process of chucking the optical disk substrate of FIG. 5 on a fixed base and applying an adhesive, and FIG. FIG. 7 is a diagram showing a manufacturing process of the optical disk after the adhesive of FIG. 6 is applied.

First, a light-transmitting substrate for manufacturing an optical disk and each layer formed thereon will be described with reference to FIG. The light transmitting substrate 40 has a bending strength of 8000 to 120 according to the measurement method ASTM D790, such as polycarbonate, polyolefin, and polymethyl methacrylate.
It is made of a thermoplastic resin of 00 N / cm ² . This light-transmitting substrate is formed into a disk shape having a thickness of 0.6 mm and a diameter of 120 mm, and groups, pits, and the like are formed on the surface.

Next, a recording layer 41 such as a phase change recording layer, a magneto-optical recording layer or an organic dye recording layer is formed on the light transmitting substrate 40. The phase-change recording layer and the magneto-optical recording layer are formed on the light-transmitting substrate by sputtering materials as needed. Further, the organic dye recording layer, on the organic dye layer formed by applying an organic dye solution on a light-transmitting substrate by a spin coating method and drying,
For example, it is obtained by forming a metal reflection layer of Au, Ag, or the like.
In this manner, a known recording / reproducing recording layer is provided according to the purpose, for example, a write-once DVD-R, a rewritable DVD-RAM, -RW, and + RW. Alternatively, a read-only DVD-ROM in which pre-pits serving as information are formed in advance on a light-transmitting substrate and a metal reflection layer such as A1 or Ag is formed thereon may be used.

For the purpose of protecting the recording layer 41, an organic protective layer 42 mainly made of a colorless and transparent UV-curable acrylic resin or the like is formed on the recording layer 41 by spin coating, screen printing, or the like. It is formed with a thickness of 50 μm. As described above, the first optical disk substrate 11 is obtained by forming the recording layer 41 and the organic protective layer 42 on the light transmitting substrate 40. The lower surface 40 of the light transmitting substrate 40
a may be formed with a hard coat layer.

Next, as shown in FIG. 6A, a lower surface 40a faces the fixed surface 23 on a circular concave fixed surface 23 of a fixed base 22 similar to the chucking device 21 of FIG. The first optical disc substrate 11 is arranged as described above. And
The first optical disk substrate 11 is chucked with respect to the fixed surface 23 by sucking the lower surface 40a side through the many suction holes 23, 24, 25.

Next, as shown in FIG. 6B, the adhesive surface 42a, which is the upper surface (the surface of the protective layer 42) of the first optical disk substrate 11, is covered with a screen 31 having a mesh shape. By moving the adhesive member 32 in the horizontal direction H while pressing the adhesive member 32 downward from the top in the vertical direction V, an adhesive 33 made of a slow-acting ultraviolet-curable epoxy resin is applied to the adhesive surface 42a via the screen 31 and the first Adhesive layer 11a on adhesive surface 42a of optical disk substrate 11 (FIG. 7)
To form At this time, since the first optical disc substrate 11 on the fixed surface 23 is hardly deformed by the suction as described above, the adhesive can be uniformly applied on the adhesive surface 42a, and the adhesive layer 11a (FIG. 7) has a uniform thickness, and no coating unevenness occurs. Further, the first optical disk substrate 11 is securely chucked with respect to the fixed surface 23, so that the first optical disk substrate 11 does not move together with the movement of the adhesive member 32.

The adhesive surface of the second optical disk substrate 12 (FIG. 7) composed of the same light-transmitting substrate as described above is also bonded to the adhesive made of the ultraviolet curing epoxy resin similarly to the first optical disk substrate 11. And adhesive layer 12a (FIG. 7)
To form

Next, as shown in FIG.
a and 12a are respectively applied to the first and second optical disk substrates 11 and 12 with ultraviolet light sources 4, 5 to 50, respectively.
An ultraviolet ray of about 0 to 1500 mJ / cm ² is irradiated. Thereby, the curing reaction of the adhesive starts. After a while
After the surfaces of the adhesive layers 11a and 12a are opposed to each other as shown in FIG. 7 (b), the two optical disk substrates 11 and 12 are put together and placed between the disks 6 and 7 as shown in FIG. 7 (c). Sandwich 1
The two optical disc substrates 11 and 12 are adhered to each other by applying pressure at a pressure of about 0 to 100 N / cm ² , and the curing reaction of the adhesive of the adhesive layers 11 a and 12 a proceeds to reach curing. Thus, the optical disk 13 such as a DVD is obtained.

If the suction hole is larger than the thickness of the light-transmitting substrate as in the conventional example shown in FIG. 4, uneven coating will occur during the application of the adhesive, and the mechanical accuracy of the manufactured optical disk, such as the surface deflection acceleration, will be reduced. Although the optical disk characteristics deteriorated easily and the optical disk characteristics were also likely to deteriorate, such a defect can be prevented by the manufacturing method of manufacturing an optical disk as described above. According to this manufacturing method, since the adhesive can be uniformly applied to the bonding surface by appropriately adsorbing the optical disk substrate to the fixed surface, mechanical accuracy and recording such as surface runout acceleration of the optical disk after bonding are achieved. The reproduction characteristics can be improved.

The conditions such as the thread thickness of the screen (plate) used in the screen printing method in the adhesive application step in FIG. 6B and the roughness of the mesh (mesh-shaped portion where the adhesive passes) are as follows. It is appropriately selected depending on the viscosity of the adhesive used, the thickness of the adhesive to be applied, and the like. The thickness of the applied adhesive can be adjusted by the thickness of the plate thread.

The integrated amount of ultraviolet rays in the step of irradiating ultraviolet rays shown in FIG. 7A differs depending on the adhesive used, but is preferably about 500 to 1500 mJ / cm ² .

Various late-acting UV-curable epoxy resin adhesives have been developed.
1000 to 100000 cps (BH type viscometer, 2
rpm). The slow-acting ultraviolet-curable epoxy resin adhesive mainly comprises an epoxy resin and an energy ray polymerization initiator. The curing reaction of an epoxy resin adhesive is generally widely known, and an amine or acid anhydride is used as an energy ray polymerization initiator, and the epoxy resins are ion-polymerized by anionic polymerization or cationic polymerization. It is expected to be a system that has both the speed of reactivity and the cured physical properties of epoxy resins. Furthermore, by adding a substance having an effect of delaying the curing of the epoxy resin, the type of the epoxy resin, the irradiation amount of the ultraviolet resin, or the epoxy resin,
It is possible to adjust the speed of the curing reaction.

As the adhesive composition, the residual ratio of epoxy groups (the amount of epoxy groups after irradiation with energy rays such as ultraviolet rays with respect to the initial amount of epoxy groups determined by infrared absorption spectrum analysis or the like). The percentage is expressed in%)
However, irradiation is usually performed by adjusting the energy dose of ultraviolet rays or the like so as to be in the range of 50 to 95%, preferably 60 to 90%. When the residual ratio of the epoxy group is 95% or more, curing is not sufficiently performed, and when the residual ratio is 50% or less, adhesiveness is deteriorated.

When the adhesive is irradiated with ultraviolet rays in advance using the same adhesive and then applied to the optical disk substrate and bonded, or when the adhesive is applied to the optical disk substrate,
Simultaneously irradiating ultraviolet rays and bonding them together is also applicable.

Further, the negative pressure sucked by each suction hole is not particularly limited, and can be appropriately selected. Further, the thickness of the light-transmitting substrate made of a thermoplastic resin such as polycarbonate, polyolefin, and polymethyl methacrylate is not particularly limited. However, if it is about 0.1 mm to 1.2 mm, a chucking device as shown in FIG. The same effect of preventing deformation can be obtained by appropriately changing the diameter of the suction hole converted into a circle.

Further, the second optical disk substrate 12 corresponds to FIG.
The configuration may be the same as that of the first optical disk substrate 11, or may be a dummy substrate. In the former case, the optical disk has a double-sided specification, and in the latter case, the optical disk has a single-sided specification. In addition, the application step of the adhesive in FIG. 6B is performed by a screen printing method, but may be applied by a spin coater method or a roll coater method depending on an adhesive material to be used.

[0042]

Next, the method of manufacturing the above optical disk will be described more specifically with reference to Examples 1 to 3 and Comparative Examples 1 to 3.

<Example 1>

Referring to FIGS. 5 to 7, the thickness is 0.6 mm, the diameter is 120 mm, and the center hole diameter is 15 mm.
mm transparent resin substrate 40 made of polycarbonate resin,
After a predetermined format information previously formed on the stamper is transferred by injection molding, a recording layer 41 having a known phase change recording film structure is formed thereon by a sputtering method, and an acrylic resin die cure is further formed thereon. Clear S
D318 (manufactured by Dainippon Ink and Chemicals, Inc.) was applied by a spin coating method and cured by irradiating ultraviolet rays to form an organic protective layer 42 of about 5 μm, whereby the first optical disc substrate 11 was produced. Similarly, a second optical disk substrate 12 was manufactured.

Next, as shown in FIGS. 6A and 6B, the disc-shaped adhesive surface 11 on the organic protective layer of each optical disc substrate is formed.
SK7000 (Sony Chemical Co., Ltd.) which is a slow-acting UV-curable epoxy resin adhesive
Was applied by a screen printing method. At this time, when the area of one suction hole opened in the fixing surface 23 of the chucking device 21 in FIG. 1 was converted into a circle, the diameter of the circle was 0.5 mm.

Further, the applied adhesive layers 11a, 11b
After irradiating the surface of the substrate with ultraviolet rays of about 1000 mJ / cm ² , the surfaces of the adhesive layers 11a and 11b face each other, and the first optical disk substrate 11 and the second optical disk substrate 12 are pressed at a pressure of approximately 3 kg / cm ^2. Then, the adhesive layer was completely cured while being held on a flat plate, and bonded.

The surface deflection acceleration, which is a typical mechanical accuracy of an optical disk (DVD) as an optical recording medium obtained by bonding together, was measured by LM1200 manufactured by Ono Sokki Co., Ltd. That is, the focus and tracking servo are applied to the guide groove of the DVD, the movement of the objective lens that traces the guide groove is measured, and the amount of vertical displacement at an arbitrary measurement point (for example, 256 points) in the circumference is calculated by 2 The surface deflection acceleration in the circumferential direction was measured by differentiating twice.

<Embodiment 2>

The same as Example 1 except that the thickness of the light-transmitting substrate was 0.5 mm, and the diameter of the circle when the area of one suction hole for chucking was converted to a circle was 0.4 mm. An optical disk was manufactured under the conditions described above, and the surface runout acceleration was measured.

<Embodiment 3>

Same as Example 1 except that the thickness of the light-transmitting substrate was 1.2 mm, and the diameter of the circle when the area of one suction hole for chucking was converted to a circle was 1.0 mm. An optical disk was manufactured under the conditions described above, and the surface runout acceleration was measured.

<Comparative Example 1>

An optical disk was prepared under the same conditions as in Example 1 except that the diameter of the circle when the area of one suction hole for chucking was converted to a circle with the chucking device of FIG. 1 was 1.0 mm. It was manufactured and the surface runout acceleration was measured.

<Comparative Example 2>

Same as Example 1 except that the thickness of the light-transmitting substrate was 0.5 mm, and the diameter of one circle when the area of one suction hole for chucking was converted to a circle was 1.0 mm. An optical disk was manufactured under the conditions described above, and the surface runout acceleration was measured.

<Comparative Example 3>

Same as Example 1 except that the thickness of the light-transmitting substrate was 1.2 mm and the diameter of the circle when one suction hole for chucking was converted to a circle was 2.0 mm. An optical disk was manufactured under the conditions described above, and the surface runout acceleration was measured.

The results of Examples 1 to 3 and Comparative Examples 1 to 3 are shown in Table 1 below, including the results of observation of the state of application of the adhesive on the bonding surface of the substrate.

<Table 1> Light-transmitting substrate Diameter of converted circle Coating condition Thickness of surface runout acceleration (mm) (mm) (m / s ² ) Example 1 0.6 0.5 Evenly Good 3.5 Example 2 0.5 0.4 Unevenly good 3.0 Example 3 1.2 1.0 Unevenly good 2.5 Comparative example 1 0.6 1.0 Coating unevenness 8.5 Comparative example 2 0.0. 5 1.0 Uneven Coating Occurred 6.5 Comparative Example 3 1.2 2.0 Uneven Coating Occurred 5.0

As can be seen from Table 1, the conversion circle from the area of one suction hole of the chucking device of FIG. 1 is smaller than the thickness of the light transmitting substrate (substantially equal to the thickness of one optical disc before bonding). When the diameter is large, uneven coating occurs on the bonding surface and the surface run-out acceleration is 5.0 (m / s).
² ) The reference value for tracking the focus of the optical head of the apparatus (8 m /
s ² ). On the other hand, when the diameter of the converted circle from the area of one suction hole of the chucking device in FIG. 1 is smaller than the thickness of the light-transmitting substrate, there is no uneven coating on the adhesive surface, and the surface deflection acceleration is good. Is 3.5 (m /
s ² ) or less, which was a good result.

Embodiment 4

As a fourth embodiment, the intensity of the ultraviolet light is set to be constant and the irradiation time of the ultraviolet light is set to 0.5 seconds and 1.5 seconds in the first embodiment.
Five optical disks were produced under the same conditions except that the time was changed to 2.5 seconds and 2.5 seconds, and the surface deflection acceleration was measured.

<Comparative Example 4>

As Comparative Example 4, the diameter of the converted circle from the area of one suction hole for chucking was set to 0.5 in Example 4.
Five optical disks were manufactured under the same conditions except that the thickness was changed from 2.0 mm to 2.0 mm, and the surface runout acceleration was measured.

FIG. 8A shows the result of Example 4 and FIG.
FIG. 8 (b) shows the results of the above as the ultraviolet irradiation time on the horizontal axis. As shown in FIG. 8B, when the diameter of the converted circle from the area of one suction hole is larger than the thickness of the light-transmitting substrate, especially when the ultraviolet irradiation time is long, the surface deflection acceleration becomes large, In some cases, the reference value may exceed 8 (m / s ² ), and the value tends to vary. On the other hand, as shown in FIG. It is understood that when it is smaller than the above value, the surface runout acceleration tends to be small and stable with a small variation regardless of the change in the ultraviolet irradiation time.

As described above, when the adhesive is applied to the bonding surface of the two optical disk substrates, the chucking device shown in FIG. 1 sucks the disk surface of each optical disk substrate to perform chucking, and the fixed surface has rigidity. By converting the area of one suction hole for chucking into a circle and setting the diameter of the circle to be equal to or less than the thickness of the sucking member, mechanical accuracy such as surface deflection acceleration is stable and good. An optical disk can be obtained.

As described above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to these.
Various modifications are possible within the scope of the technical idea of the present invention. For example, the flat body chucked to the fixed surface is not limited to a disk-shaped body, but may be another shape such as a rectangular shape, a polygonal shape, and an elliptical shape.

The chucking method and the chucking device according to the present invention can be applied not only to an adhesive applying step for manufacturing an optical disk but also to a flat plate to be chucked by applying to other devices and methods. It is possible to obtain the same effect that it is difficult to deform and can be securely fixed. For example, the present invention can be applied to a driving device that fixes an optical disk and performs recording / reproduction.

[0069]

According to the chucking method and the chucking apparatus of the present invention, even if a relatively thin and rigid plate-like body such as a substrate of an optical disk or the like is sucked by negative pressure, no deformation occurs without fail. Can be chucked.

Further, according to the method for producing a flat plate of the present invention, two flat plates are bonded together by applying an adhesive while being sucked by a negative pressure to produce one flat plate. In this case, uneven application of the adhesive can be prevented, and a flat body having good adhesive quality can be manufactured. In this case, the chucking method or the chucking device of the present invention is applied when manufacturing the optical disc by bonding the two light-transmitting substrates with an adhesive by using the plate-shaped body as a disc-shaped light-transmitting substrate. This makes it difficult for the adhesive to be unevenly applied to the two light-transmitting substrates, and the manufactured optical disc has stable and favorable mechanical accuracy such as surface runout acceleration.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a main part of a chucking device according to an embodiment of the present invention.

FIG. 2 is a plan view of a fixing surface of FIG. 1;

FIG. 3 is a partial cross-sectional view for explaining an operation and an effect of the chucking device of FIG. 1;

FIG. 4 is a partial sectional view for explaining a problem of the conventional chucking device.

FIG. 5 is a cross-sectional view of the optical disk substrate before bonding in the optical disk manufacturing method according to the present embodiment.

6 is a side sectional view showing a step (a) of chucking the substrate of the optical disk of FIG. 5 on a fixed base and a step (b) of applying an adhesive.

7A to 7C are diagrams showing manufacturing steps (a), (b), and (c) of the optical disk after application of the adhesive of FIG. 6;

8A is a diagram illustrating a relationship between an ultraviolet irradiation time and a surface shake acceleration in an example, and FIG. 8B is a diagram illustrating a similar relationship in a comparative example.

[Explanation of symbols]

Reference Signs List 21 chucking device 23 fixing surface 24, 25, 26, 28 suction hole 11, 12 optical disk substrate (flat body) 30 disk-shaped body (flat body) 30a suction surface 40 light-transmitting substrate 40a lower surface of optical disk substrate ( Surface to be sucked) 42a Adhesive surface of optical disk substrate

Claims (6)

[Claims] 1. A chucking method in which a flat plate is disposed on a fixed surface, and the flat plate is chucked to the fixed surface by sucking the suction surface from a plurality of suction holes opened in the fixed surface. A method wherein the fixed surface has rigidity, the area of one of the suction holes is converted into a circle, and the diameter of the converted circle is equal to or less than the thickness of the flat plate. King way. 2. The method according to claim 1, wherein the flat plate is measured by ASTM D79.
Chucking method of claim 1 0 due to bending strength is equal to or is 8000~12000N / cm ^2. 3. A fixed surface on which a flat plate is disposed and having rigidity, and an opening in the fixed surface for sucking a suctioned surface of the flat plate and chucking the flat plate against the fixed surface. A plurality of suction holes, wherein the area of one of the suction holes is converted into a circle, and the diameter of the converted circle is equal to or less than the thickness of the flat plate. 4. The method according to claim 1, wherein the flat body is measured by ASTM D79.
0 due to the bending strength of the chucking device according to claim 3, characterized in that the 8000~12000N / cm ^2. 5. A method for manufacturing one flat plate by bonding two flat plates together, comprising: arranging a first flat plate on a fixed surface; Chucking the first plate-like body with respect to the fixing surface by sucking the suctioned surface of the first plate-like body from the plurality of suction holes by the chucking method described in the above, A step of applying an adhesive to an adhesive surface of the first flat body opposite to the suctioned surface; and a step of bonding the adhesive surface of the first flat body to the adhesive surface of the second flat body. The manufacturing method of the flat body characterized by including these. 6. The optical disk according to claim 1, wherein the first and second flat bodies are disk-shaped light-transmitting substrates, and the two light-transmitting substrates are bonded to each other with an adhesive to manufacture an optical disk. The method according to claim 5.