JP2000298887A - Manufacture of discoidal information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a discoidal information recording medium with a plurality of reflection films that are laminated one another by an adhesion layer without any holding of air bubbles. SOLUTION: In the method for manufacturing a discoidal information recording medium made of a multilayer stamper where discoidal foundation L0 with a reflection film and a discoidal stamper L1 are laminated and then the stamper is released and the reflection film is formed, a first stage for applying an adhesive to either lamination surface of the foundation L0 or the stamper L1 in the air by a specific film thickness, a second stage for overlapping the foundation and the stamper so that they approach in an axial direction each other without rotating in the vacuum atmosphere, a third stage for taking out the laminated foundation and stamper into the air and at the same time releasing the stamper from the cured adhesive, and a fourth stage for forming the reflection film on the surface of the adhesive. Then, the first to fourth stages are repeated by using another stamper Ln.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a disc-shaped information recording medium for manufacturing a disc-shaped information recording medium by bonding a plurality of disc-shaped bases with an adhesive. It is.

[0002]

2. Description of the Related Art In recent years, high-density recording media capable of recording or reproducing a large amount of information have appeared. This type of high-density recording medium is manufactured by bonding a plurality of disk-shaped substrates via an adhesive. As a disc-shaped information recording medium of this kind, for example, an optical disc, a so-called digital video disc or digital versatile disc (DVD, trade name) is particularly known. As a method of bonding a plurality of disk-shaped substrates with an adhesive, there is a method of applying a UV curable resin (ultraviolet curable resin) as an adhesive between the substrates by a spinner method.

FIG. 10 shows a conventional lamination type disc-shaped information recording medium 1. This disc-shaped information recording medium 1 is a disc-shaped or disc-shaped base L0.
And the base L1 are bonded via the bonding layer 2. A reflection film 3 is formed on one surface of the substrate L0, and a reflection film 4 is formed on one surface of the substrate L1.
Is formed, and the adhesive layer 2 adheres to the reflective films 3 and 4 side. On these bases L0 and L1, for example, an uneven portion for forming a pit shape corresponding to a predetermined signal is formed in advance, and reflective films 3 and 4 are formed on the uneven surface. Thus, when the light 5 from the optical pickup (not shown) is emitted from, for example, the substrate L0 side, the signal corresponding to the unevenness recorded on the reflection film 3 by the return light of the signal from the reflection film 3 through the transparent substrate L0. Is read, or the light of the optical pickup is applied to the reflective film 4 via the substrate L0, the reflective film 3 and the adhesive layer 2, and the reflected light from the reflective film 4
Is read.

In the conventional disk-shaped information recording medium 1 as shown in FIG. 10, when air bubbles 6 enter the adhesive layer 2, light 5 from the optical pickup is The signal recorded on the reflective film 4 cannot be read because the light is refracted at the portion and is not irradiated on the signal surface to be read, or the amount of return light is less than the required light amount.

FIGS. 11 to 13 show examples in which an adhesive is applied by a spinner method. In FIG. 11, after the adhesive 7 is dropped in a ring shape on the inside of one disk-shaped base L0, the other base L1 is overlaid on the base L0. Thereafter, the stacked substrates L0 and L1 are both driven to rotate around the central axis O at high speed, whereby the adhesive 7 extends and spreads between the substrates L0 and L1 by centrifugal force, and the film thickness becomes a predetermined value. Adjusted.

However, in this method, the bases L0,
If the speed when layering L1 is fast, depending on the speed,
As shown in FIGS. 12 and 13, from the relationship between the air pressure generated in the base L0 and the viscosity of the adhesive 7, the air on the lower surface of the base L1 pushes away the adhesive 7, and the base L1 comes into contact with the adhesive 7. When doing so, the adhesive 7 embraces the air bubbles 6. Most of the foam 6 is blown out of the bonding surface together with the adhesive 7 by spinning, but cannot be completely eliminated. The embrace of bubble 6
If the speed at which the substrates L0 and L1 are overlapped is reduced, the speed can be reduced, but it cannot be completely eliminated.

On the other hand, in the case of a disc-shaped information recording medium comprising a multi-layer disc base having two or more layers manufactured by the so-called 2P method, the base L1 having the reflective film 4 is provided.
Instead, after the master is bonded to the base L0 with the adhesive layer 2, the master is peeled off, and the second reflection film 4 is formed on the adhesive layer 2. Then, the same operation is repeated to form a plurality of reflective films, and thereafter, the reflective film on the surface is covered with a protective film to manufacture a disc-shaped information recording medium.

[0008]

However, also in this case, as in the case of bonding the substrates L0 and L1, air bubbles are generated in the bonding layer when the substrate L0 and the master are bonded. There was a problem of mixing.

In view of the above, it is an object of the present invention to provide a method of manufacturing a disc-shaped information recording medium having a plurality of reflective films bonded to each other by an adhesive layer that does not entrap air bubbles. And

[0010]

SUMMARY OF THE INVENTION According to the present invention, there is provided a disk-shaped base having a reflective film and a disk-shaped master are bonded together with an adhesive layer. A method of manufacturing a disc-shaped information recording medium comprising a multilayer substrate, in which a reflective film is formed thereon, wherein an adhesive is applied in air to a bonding surface of either the substrate or the master. The first step of coating with a predetermined film thickness, the second step of laminating the base and the master in a vacuum atmosphere without rotating them and approaching each other in the axial direction relatively to each other, and laminating each other A third step of removing the base and the master to the atmosphere, peeling the master from the cured adhesive, and a fourth step of forming a reflective film on the surface of the adhesive, and further including another master And repeat steps 1 through 4 above. By returning to forming the reflective film multiple layers of the base plate surface, the method for producing a disc-shaped information recording medium, is achieved.

According to the first aspect of the present invention, when the disc-shaped base and the disc-shaped master are bonded with an adhesive, first, in the first stage, either the base or the master is bonded. After applying the adhesive to the surface in the air,
Both the base and the master are placed in a vacuum atmosphere, and the base and the master are superimposed on each other without rotating so as to be bonded.

Thus, the application of the adhesive to the base or the master is easily performed by applying the adhesive to a predetermined thickness in the atmosphere. By disposing the base and the master in a vacuum atmosphere and superimposing them on each other, no air bubbles are trapped in the adhesive, and there is no need to apply a rotational force to the base and the master. Therefore, the base and the master can be securely adhered and bonded in a short time and easily.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. still,
Since the embodiments described below are preferred specific examples of the present invention, various technically preferred limitations are added.
The scope of the present invention is not limited to these embodiments unless otherwise specified in the following description.

FIG. 1 shows the configuration of a disc-shaped information recording medium manufacturing apparatus for carrying out the disc-shaped information recording medium manufacturing method according to the present embodiment. In FIG. 1, a disc-shaped information recording medium manufacturing apparatus 10 includes a first storage unit 12, a second storage unit 14, a moving unit 16, a master pressing unit 18, and the like. The first accommodating portion 12 and the second accommodating portion 14 constitute a part of the vacuum chamber 20, and the first accommodating section 12 and the second accommodating section 14 are provided in one part and the other part of the vacuum chamber 20. Is provided. The inside of the vacuum chamber 20 is constantly evacuated by the operation of the exhaust pump 22, and is maintained at a predetermined vacuum pressure, for example, a constant pressure in a range of 100 Pa to 20,000 Pa.

The pressure of the vacuum atmosphere in the vacuum chamber 20 is
If it is smaller than 100 Pa, a small amount of volatile components will start to be emitted from the adhesive, which may impair the adhesive performance. This pressure is 1
Even if the pressure is smaller than 00 Pa, the pressure becomes a molecular level pressure and is not related to the effect of the present invention, and the evacuation time becomes longer.
A molecular pump or the like is required, resulting in a useless configuration. On the other hand, if the pressure of the vacuum atmosphere is higher than 20,000 Pa, the existence of air cannot be ignored, which is contrary to the intention of the present invention.

The first accommodating section 12 has an access port 24, a load lock mechanism 26, and the like. The doorway 24
For example, it is formed in a circular shape on the upper surface of the casing 28 of the vacuum chamber 20. The load lock mechanism 26 includes a head 30,
It is composed of a transfer tray 32 of a base and a support 60. The head 30 of the load lock mechanism 26 can be moved in the Z direction (vertical direction) by a driving source (not shown). When the head 30 is lowered, the head 30 moves through the entrance 24 so that air does not enter or exit. It can be tightly sealed.

The transfer tray 32 of the base is fixed to a rod 36 of a cylinder 34. Thereby, the cylinder 3
When 4 is operated, the transfer tray 32 of the base moves up and down by a predetermined stroke in the Z direction. On the transfer tray 32 of the base, for example, the base L0 coated with an adhesive can be placed. The access port 24 is evacuated to the outside by an exhaust pump (not shown) via an exhaust valve 40.

On the other hand, the second storage section 14 is
The second accommodating portion 14 has a master disk slot 124 and a load lock mechanism 126. The inlet / outlet 124 for the master is formed in an upper part of the casing 28. The load lock mechanism 126 includes a head 130, a master plate delivery tray 132, and a support 62. The head 130 can be moved in the Z direction by driving means (not shown), and when the head 130 is lowered, the access opening 124 can be tightly sealed so that air does not leak.

The delivery tray 132 of the master is a cylinder 13
4 is fixed to the rod 136. When the cylinder 134 operates, the transfer tray 132 of the master moves up and down by a predetermined stroke in the Z direction. By moving the cylinder upward, the transfer tray 132 of the master presses the support 62 against the inner wall of the vacuum chamber, and the inside of the vacuum chamber 20 and the inlet 12
4 is shut off. Furthermore, the delivery plate 132 of the master is
For example, the base L0 sent from the first storage unit 12 by the moving unit 16 can be held.

Next, the moving section 16 is disposed in the vacuum chamber 20 between the first housing section 12 and the second housing section 14.
The moving section 16 is provided with a transfer tray 32 on the base of the first accommodation section 12.
Is temporarily received and rotated, so that the base L0 is transferred to the master delivery tray 132 side of the second storage unit 14. The moving unit 16 includes the rotating arm 5
0, and an actuator 52 for rotating the rotary arm 50. The actuator 52 is fixed to the casing 28 together with the cylinders 34 and 134. The operating shaft 54 of the actuator 52 is fixed to the center of the rotary arm 50,
By operating 2, the index can be performed, for example, every 180 degrees.

At one end of the rotary arm 50, for example, a support 60 for supporting the base L0 is provided.
At the other end of the rotary arm 50, for example, a support 62 for supporting the master L1 is provided. These supports 60 and 62 allow, for example, the base L0 placed on the base delivery tray 32 or the master delivery tray 132 to be transferred to the base delivery tray 32 or the master delivery tray 32 by lowering the base delivery tray 32 in the Z direction. 132 can be supported. The control unit 100 controls the cylinders 34 and 134, the actuator 52, and the head 3
In addition to controlling the operation of 0, 130, the exhaust pump 22 and the like can be controlled.

Next, a method for manufacturing a disc-shaped information recording medium according to the first embodiment of the present invention will be described with reference to the flowchart shown in FIG. Step S first
At T1, the base L0 is formed. The substrate L0 can be made of, for example, a material such as polycarbonate having a light-transmitting property, for example, in the manner of molding a substrate of an optical disk that has been conventionally used. An uneven surface is formed. Next, step ST
At 2, a reflective film is formed on the signal pit surface of the substrate L0. The reflection film is made of a metal film, for example, aluminum, gold, silver, a semiconductor, or the like.

Subsequently, in step ST3, a resist as an adhesive, for example, a UV curing resist is uniformly applied on the reflective film of the base L0 in the air. Here, the adhesive is not limited to the resist, and other adhesives are also used. As a method of applying the resist, for example, a conventionally used spinner method is adopted, but another method such as a silk screen method may be used. The feature of the application of the resist is that it is applied in the air as shown in step ST3 of FIG. Thereby, the resist can be easily applied to the base L0.

Thereafter, in step ST4, the substrate L0 is put in a vacuum chamber. On the other hand, in another process parallel to the above, the first master disc L
1 are formed, and in step ST6, the first master L1 is put in a vacuum chamber. Then, in step ST7,
As shown in FIG. 1 and FIGS. 3 to 5, the base L0 and the first master L1 are superimposed on each other and adhered in a vacuum chamber.

In FIGS. 1 and 3, the head 30 of the load lock mechanism 26 is raised in the Z direction,
The substrate L0 on which the reflection film is formed and the resist is applied is accommodated in the access opening 24 of the substrate. In this state, as shown in FIG.
Is placed on the delivery tray 32 of the base. At the same time as inserting the base L0 into the access port 24 of the first storage section 12, or at another time, the access port 124 of the second storage section 14
On the side, a first master L1 is prepared. That is, the head 130 of the load lock mechanism 126 holds the first master L1 by suction.

The head 30 shown in FIG. 3 is lowered in the Z direction to close and close the access port 24, and the cylinder 34 is operated to lower the transfer tray 32 of the base in the Z direction. Thereby, as shown in FIG. 4, the base L0 is transferred from the transfer tray 32 of the base to the support 60 side. At this time, the transfer plate 132 of the master is also lowered in the Z direction by the operation of the cylinder 134.

When the actuator shown in FIG. 4 is operated, the rotary arm 50 rotates 180 degrees. As a result, the base L0 placed on the support 60 is located on the second storage section 24 side as shown in FIG. Thereafter, the cylinder 134 is operated to move up from the state shown in FIG. 5 in the Z direction, so that the transfer tray 132 of the master receives the base L0 from the support 60 and supports it. In this state, the second storage unit 1
The base L0 located on the fourth side is located immediately below the first master L1, and the first master L on which the resist is not applied.
It is opposed to 1.

When the head 130 is lowered in the Z direction, the head 130 closes the access opening 124 completely tightly. At this time, the head 30 also closes the access opening 24 completely tightly. From this, the inside of the vacuum chamber 20 is maintained at a predetermined vacuum pressure, preferably 100 Pa to 2000 Pa.
It is kept at any constant value within the range of 0 Pa. Then, as the rod 136 of the cylinder 134 rises in the Z direction, the base L0 and the first master L1 relatively approach in the axial direction of the base, that is, the Z direction in step ST7 of FIG. Completely adhered through. Thus, the shape of the signal pits formed on the surface of the first master L1 is transferred to the surface of the resist. This bonding state is performed within a predetermined vacuum pressure of the vacuum chamber 20. Therefore, no air bubbles are mixed into the resist, and the air is completely drawn from the adhesive and discharged to the outside by the exhaust pump 22. In addition, since the base L0 and the first master L1 are superposed only by relatively linearly moving in the Z direction without being rotated, they can be bonded to each other only by the resist. As a result, the base L0 and the first master L1 can be easily bonded together, and the production speed can be dramatically improved as compared with the case of rotating and bonding. In addition, since the resist is not scattered around in comparison with the case of rotating, the production speed can be further increased.

Then, the disc-shaped information recording medium D comprising the base L0 and the first master L1 bonded in this manner.
Is taken out of the vacuum chamber 20 by lifting the head 130 in the Z direction in step ST8. Here, the base L0 coated with the resist is stored in the first storage unit 12, and the first master L1 not coated with the resist is stored in the second storage unit 14 side. However, the present invention is not limited to this, and a resist may be applied to the first master L1. In this case, instead of the above-described step ST3, as shown in FIG. 6, in step ST3a, a resist as an adhesive is uniformly applied to the first master L1 in the air.

Next, the information recording medium D is stored in step S
At T9, the resist is cured. Thus, the signal pits formed on the first master L1 are transferred to the surface of the cured resist film. The hardening of the resist is performed in the vacuum chamber 20 as shown in FIG. 7, and thereafter, the information recording medium D is taken out from the vacuum chamber 20, that is, step ST8 and step ST9 are performed in reverse order. Is also good. In this case, the hardening of the resist is performed by, for example, as shown in FIG.
This is performed by ultraviolet rays emitted from a UV lamp unit 138 incorporated therein.

Thereafter, in step ST10, the first master disc L1 is peeled off from the cured resist film. Then, in step ST11, a reflection film is formed on the cured resist film, so that the step ST2 is formed on the substrate L0.
And the second reflective film formed in step ST11. Here, a disk-shaped information recording medium having two layers of reflective films is obtained.

Then, as shown in FIG. 2A, a plurality of reflective layers are formed on the substrate L0 on which the two-layer reflective film is formed by using a new master a desired number of times, for example. Can be formed. That is, on the path indicated by the symbol A,
The new master supplied in step ST12, that is, the second master L2, is stored in step ST4 and step ST4 respectively.
In step S6, the substrate L0 is placed in the vacuum chamber 20 and steps ST7 to ST11 are repeated, whereby
Above, a (n + 1) -layer reflective film is formed for the number of repetitions n.

After that, in step ST13, a protective film is formed on the final reflection film, and then, in step ST14, label printing is performed using printing ink. Here, printing of the label is performed on the surface of the information recording medium D opposite to the reading surface. As described above, the manufacture of the multilayer disk-shaped information recording medium is completed.

In this embodiment, a resist is previously applied to the substrate L0 or the master Ln in the air instead of in the vacuum chamber 20, and then the base L0 and the master Ln are axially moved in the vacuum chamber. The substrate L0 and the master Ln are completely adhered only by the resist, so that the substrate L0 and the master Ln are completely bonded only by the resist. Since there is no air between the surface to be bonded and the surface of the base or the master, the familiarity of the resist is improved, and the flatness is maintained.

The master pressing section 18 shown in FIG. 1 is composed of the above-described cylinder 134, a master delivery tray 132, and the like. When the master pressing section 18 tries to press the base L0 relatively to the master L1 as shown in FIG. 5, the elastic force applying section 70 can add an elastic force to some extent. That is, the elastic force applying section 7
Numeral 0 has a moving part 71 and a spring 72. When the base L0 is pressed against the base L1, the spring 72 can apply a force in the Z direction via the moving part 71. As a result, the base L0 and the master L1 can be stuck exactly via the resist. Such an elastic addition portion 70 is similarly provided on the other base delivery tray 32.

In the present embodiment, it is not necessary to reduce the operating speed of the bonding mechanism as in the prior art in order to prevent air bubbles from being entrapped. In addition, it is possible to eliminate defects at the time of manufacturing a disc-shaped information recording medium without mixing air bubbles into the resist, and to omit defect inspection. Further, since the resist can be applied to the base or the master in advance in the air before the base and the master are bonded to each other, the resist can be accurately applied to a desired position of the base or the master. As a result, the finished state of the disc-shaped information recording medium becomes clear.

As described above, according to the present embodiment, a disc-shaped information recording medium provided with the two-layer reflecting films R0 and R1 shown in FIG. 9A, or a multilayer information recording medium shown in FIG. A disc-shaped information recording medium having the reflective films R0, R1, R2 is manufactured. However, not limited to this,
By bonding two disc-shaped information recording media shown in FIG. 9A or FIG.
It is also possible to manufacture a multi-layer disc-shaped information recording medium having the structure shown in FIGS.

Here, in the case of manufacturing a disk-shaped information recording medium having a double-sided multilayer structure as shown in FIG. 9C or 9D, in the manufacturing apparatus 10 shown in FIG.
Instead of the master L1, a single-sided multi-layered disc-shaped information recording medium manufactured in advance is placed in the vacuum chamber 20 in steps ST4 and ST6, respectively, and the above-described bonding of the base L0 and the master L1 is performed. As in the case described above, by laminating each other with a resist, a double-sided, multilayered disk-shaped information recording medium in which air bubbles are not similarly mixed is produced.

In the above-described embodiment, a UV-curable resist is used as an adhesive.
Clearly, other types of resists or other adhesives may be used. Further, in the above-described embodiment, the protection film is formed in step ST13 of FIG. 2, but is not limited thereto, and the protection film may not be formed.
In this case, if a resist of a material that does not corrode the reflective film is used for the material of the reflective film, the adhesive covers the reflective film, so that the adhesive protects the reflective film.

[0040]

As described above, according to the present invention, when the disc-shaped base and the disc-shaped master are bonded together with an adhesive, first of all, in the first stage, either of the base or the master is required. After an adhesive is applied to one of the bonding surfaces in the air, both the base and the master are placed in a vacuum atmosphere, and the base and the master are laminated by rotating without rotating. Thus, the application of the adhesive to the base or the master is easily performed by applying the adhesive to a predetermined film thickness in the atmosphere. By disposing the base and the master in a vacuum atmosphere and superimposing them on each other, no air bubbles are trapped in the adhesive, and there is no need to apply a rotational force to the base and the master. Therefore, the base and master are securely and easily bonded in a short time,
Can be laminated. Thus, according to the present invention, it is possible to provide a method of manufacturing a disc-shaped information recording medium having a plurality of reflective films bonded to each other by an adhesive layer that does not embrace air bubbles.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an apparatus for manufacturing a disc-shaped information recording medium for performing a manufacturing method according to the present invention.

FIG. 2 is a flowchart showing an embodiment of a method for manufacturing a disc-shaped information recording medium according to the present invention using the manufacturing apparatus of FIG. 1;

FIG. 3 is a schematic sectional view showing a manufacturing process in the manufacturing apparatus of FIG.

FIG. 4 is a schematic sectional view showing a state further advanced from the manufacturing process of FIG. 3;

FIG. 5 is a schematic sectional view showing a further advanced manufacturing process in the state of FIG. 4;

FIG. 6 is a flowchart showing a part of a modification of the manufacturing method of FIG. 2;

FIG. 7 is a flowchart showing a part of another modification of the manufacturing method of FIG. 2;

FIG. 8 is a partial sectional view showing a main part for curing a resist in the manufacturing apparatus of FIG. 1;

FIG. 9 is a schematic sectional view showing various disk-shaped information recording media manufactured according to the present invention.

FIG. 10 is a schematic sectional view showing an example of a disc-shaped information recording medium manufactured by a conventional manufacturing method.

FIG. 11 is a partially enlarged sectional view showing a state where an adhesive is dropped by a conventional manufacturing method.

FIG. 12 is a diagram showing a state where a plurality of substrates are about to be bonded by the dropped adhesive of FIG. 11;

13 is a partially enlarged cross-sectional view showing a state in which air bubbles are mixed in the adhesive between the substrates in FIG. 12;

[Explanation of symbols]

Reference numeral 10: apparatus for manufacturing a disc-shaped information recording medium, 12
... First accommodation section, 14 ... Second accommodation section, 16 ...
Base moving unit, 18: master press unit, 20: vacuum chamber, D: disc-shaped information recording medium, L0 ...
Base, L1 ... first master.

Claims (3)

[Claims] 1. A multi-layer substrate in which a disc-shaped base provided with a reflective film and a disc-shaped master are bonded by an adhesive layer, and then the master is peeled off and a reflective film is formed on the adhesive layer. A method for manufacturing a disc-shaped information recording medium comprising:
A first step of applying an adhesive in a predetermined film thickness in the air, and a second step of superimposing the base and the master in a vacuum atmosphere without rotating them and relatively approaching each other in the axial direction. A third step of removing the base and the master bonded together into the atmosphere and peeling the master from the cured adhesive, and a fourth step of forming a reflective film on the surface of the adhesive. Manufacturing a disc-shaped information recording medium, wherein a plurality of reflective films are formed on the substrate surface by repeating the above first to fourth steps using still another master disc. Method. 2. In the third step, after curing the adhesive,
2. The method for manufacturing a disc-shaped information recording medium according to claim 1, wherein the base and the master attached to each other are taken out into the atmosphere. 3. The disk-shaped information recording device according to claim 1, wherein, in the third step, the adhesive is cured after the base and the master attached to each other are taken out into the atmosphere. The method of manufacturing the medium.