JP2010067336A - Vacuum transfer device and vacuum transfer method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum transfer device reducing contamination in the device and reducing maintenance work, and to provide a vacuum transfer method. <P>SOLUTION: A desired gas is injected into a main vacuum chamber 40 for transfer to generate a pressure difference in the main vacuum chamber 40. Thereby, an air flow is forcibly generated in the main vacuum chamber 40, which prevents a volatile substance generated upon transferring an uneven pattern onto a UV-curable resin layer on a disk substrate 1, from adhering on an undesired part in the device in the main vacuum chamber 40. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vacuum transfer apparatus that transfers a concavo-convex pattern to a disk substrate using a stamper in a vacuum space, and a vacuum transfer method.

  In the optical disc manufacturing process, a stamper is pressed against the photoreactive resin layer spread on the disc substrate, and the photoreactive resin layer is cured, so that a pit pattern or a groove pattern formed on the stamper Transferring the concavo-convex pattern is performed.

  Patent Document 1 listed below describes an optical disk manufacturing apparatus that can manufacture a two-layer high-density recording optical disk with high quality. Patent Document 2 below describes a method for manufacturing an optical disc that can prevent bubbles from entering between the optical disc and the stamper in the optical disc manufacturing process.

JP 2005-310247 A JP 2004-303385 A

  When transferring a concavo-convex pattern such as a pit / land or a groove (groove) of a disk substrate using a stamper, the following procedure is usually performed.

First, an uncured ultraviolet curable resin is spread on a disk substrate by spin coating.
Then, a stamper having an uneven pattern is pressed against the layer of the ultraviolet curable resin. In this state, ultraviolet irradiation is performed to cure the ultraviolet curable resin layer. Then, the stamper is peeled off from the disk substrate after curing.

Here, when transferring such a concavo-convex pattern, when the stamper is pressed against the uncured ultraviolet curable resin layer, bubbles in the resin layer may be generated or dust may be involved. This adversely affects the shape of the fine concavo-convex pattern, which ultimately affects the disc playback signal.
Therefore, a technique is known in which the above-described transfer process is executed in a vacuum space using a vacuum transfer device in order to prevent generation of bubbles and the like.

  However, in a conventional vacuum transfer apparatus, when a disk substrate coated with an uncured ultraviolet curable resin is carried into the vacuum chamber, the ultraviolet curable resin partially volatilizes in the vacuum, and the volatiles adhere to the vacuum chamber. The problem that occurs. Moreover, the malfunction that the volatile component produced | generated when an ultraviolet curable resin hardens | cures adheres in a vacuum chamber also arises. The problem will be described in detail below.

  A conventional vacuum transfer apparatus has a holding table made of quartz glass having a high ultraviolet transmittance for holding a disk substrate. Then, the disk substrate is placed on a holding table made of quartz glass, and the ultraviolet curable resin spread on the disk substrate is cured by passing through the holding table and irradiating with ultraviolet rays.

  However, when a volatile component adheres to the surface of the holding table in the curing stage of the ultraviolet curable resin, an ultraviolet curable resin film is laminated on the quartz glass constituting the holding table. If it does so, the ultraviolet transmittance of a holding table will fall, the hardening defect of the ultraviolet curable resin on a disk substrate will generate | occur | produce, and it will cause a transfer defect and a failure when peeling a disk substrate from a stamper. In such a case, in such a vacuum transfer apparatus, since the operation rate as the apparatus is lowered, some countermeasure is required.

  As countermeasures against volatile substances in the vacuum transfer device, conventionally, volatiles are volatilized by putting parts that adhere volatiles into the vacuum chamber, or irradiating the volatile substances in the vacuum chamber with light or the like before adhesion. There are known methods such as removing an object or removing it by reacting with another reactive gas. However, it is difficult to implement these methods with an actual vacuum transfer apparatus, and a new improvement measure is required to solve the problem.

  In view of the above points, the present invention provides a vacuum transfer apparatus and a method for manufacturing the same that reduce dirt adhered to the apparatus and reduce maintenance.

  In order to solve the above problems and achieve the object of the present invention, the vacuum transfer apparatus of the present invention is evacuated by a vacuum suction mechanism, and has a preliminary vacuum chamber that can be opened to the atmosphere by an atmosphere release mechanism, and a vacuum suction mechanism. A main vacuum chamber to be evacuated. Then, a substrate transport unit that carries the disk substrate into and out of the preliminary vacuum chamber and a disk substrate on which the ultraviolet curable resin is spread are placed, and the disk substrate is transported between the preliminary vacuum chamber and the main vacuum chamber. And a transfer unit that performs a transfer process of transferring the concave / convex pattern to the disk substrate using a stamper in the main vacuum chamber. In addition, an ultraviolet irradiation unit that irradiates the disk substrate mounted on the inter-vacuum chamber transfer unit with ultraviolet rays, and in operation, a desired gas is injected into the main vacuum chamber to generate a differential pressure in the main vacuum chamber. And a pressurizing mechanism.

  In the vacuum transfer apparatus of the present invention, an airflow is forcibly generated by generating a differential pressure in the main vacuum chamber in the operating state of the apparatus. Thereby, the volatile substance of the ultraviolet curable resin on the disk substrate generated in vacuum is exhausted to the outside of the apparatus according to the air flow.

  The vacuum transfer method of the present invention includes a step of evacuating a main vacuum chamber and a step of carrying a disk substrate on which an uncured ultraviolet curable resin layer is formed into a preliminary vacuum chamber. Then, the step of placing the disk substrate carried into the preliminary vacuum chamber on the inter-vacuum transfer section that divides the main vacuum chamber into the upper vacuum chamber and the lower vacuum chamber, the step of evacuating the preliminary vacuum chamber, the preliminary vacuum A step of conveying from the chamber to the main vacuum chamber. Furthermore, by injecting a desired gas into the lower main vacuum chamber, the pressure in the lower main vacuum chamber is made higher than the pressure in the upper main vacuum chamber, and a desired stamper is pressed against the ultraviolet curable resin layer. At the same time, a step of irradiating the ultraviolet curable resin layer with ultraviolet rays through the conveyance section between the vacuum chambers from the lower main vacuum chamber side is included.

  In the vacuum transfer method of the present invention, a differential pressure can be generated between the lower main vacuum chamber and the upper main vacuum chamber by injecting a desired gas into the lower main vacuum chamber. Thereby, the gas injected into the lower main vacuum chamber slightly flows into the upper main vacuum chamber, and an air flow is generated. Thereby, the volatile substance of the ultraviolet curable resin on the disk substrate generated in a vacuum is exhausted out of the apparatus according to the air current.

  According to the present invention, in a vacuum, volatile substances generated from the ultraviolet curable resin on the disk substrate are exhausted out of the apparatus according to the airflow. Thereby, it can prevent that a volatile substance adheres to the unnecessary part in an apparatus.

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

[Optical Disc Manufacturing Method]
First, in order to facilitate understanding of the embodiment of the present invention described below, an optical disk manufacturing method will be described with reference to FIGS.

  FIG. 1 shows a flow of an optical disk manufacturing method, and FIGS. 2A to 2D and FIGS. 3E to H show schematic cross-sectional configurations showing the manufacturing process of the optical disk. In this example, the manufacture of a read-only dual-layer disc having two recording layers, L0 layer and L1 layer, will be described. When manufacturing a two-layer disc, a disc master having a pit pattern as information to be recorded in the L0 layer and a disc master having a pit pattern for information to be recorded in the L1 layer are prepared. A stamper for forming the L0 layer (hereinafter referred to as L0 layer stamper) and a stamper for forming the L1 layer (hereinafter referred to as L1 layer stamper) are produced from the master. The optical disk manufacturing process shown in FIG. 1 is a process of manufacturing an optical disk using the L0 layer stamper and the L1 layer stamper.

  First, the disk substrate 1 on which the pit pattern constituting the L0 layer is formed is formed by injection molding (step F101). FIG. 2A shows a schematic cross-sectional configuration of a mold used when the disk substrate 1 having the L0 layer is formed. In the mold, the concave lower cavity 120 and the concave upper cavity 121 are combined so that the concave surfaces are arranged inside each other. An L0 layer stamper 104 for transferring information pits of the L0 layer is disposed on the concave surface of the lower cavity 120. The L0 layer stamper 104 is formed with an uneven pattern 104a of information pits. A disk substrate 1 on which an L0 pit pattern 3 as shown in FIG. 2B is formed by injecting, for example, polycarbonate resin into a space formed by combining the lower cavity 120 and the upper cavity 121 is cured. can get. In addition, the injection-molded disk substrate 1 is configured to have a center hole 2 by opening the center part to a predetermined size.

  By the way, in the manufacturing process of the read-only optical disc in this example, the L0 layer stamper 104 on which the concave / convex pattern of information pits is formed is used as the emboss pit. On the other hand, in a manufacturing process of a recordable optical disc such as a write-once disc or a rewritable disc, a stamper having a concavo-convex pattern for forming a groove (wobbling groove) serving as a recording track is disposed.

  The disk substrate 1 formed as described above has a signal reading surface on the side where the L0 pit pattern 3 constituting the L0 layer is formed.

  Subsequently, as shown in FIGS. 2C and 2D, a reflective film (hereinafter referred to as an L0 layer reflective film) 4 is formed on the L0 pit pattern 3 by using a sputtering method (step F102). FIG. 2D is an enlarged view of a main part of FIG. 2C. The L0 layer reflective film 4 is formed of, for example, an Ag alloy and is formed using a sputtering method.

Next, an ultraviolet curable resin is spread on the L0 layer reflective film 4 of the disk substrate 1 on which the L0 layer is formed by spin coating. Then, the L1 layer stamper is pressed against the uncured UV curable resin layer, and the UV curable resin layer pressed with the L1 layer stamper is irradiated with ultraviolet rays.
By this process, the ultraviolet curable resin pressed with the stamper is cured, and as shown in FIG. 3E, the spacer layer 5 and the L1 pit pattern 6 constituting the L1 layer are formed (step F103).
This transfer process is a process performed in the vacuum transfer apparatus of the present invention.

  Subsequently, as shown in FIGS. 3F and 3G, a reflective film (hereinafter referred to as an L1 layer reflective film) 7 is formed on the L1 pit pattern 6 formed in the layer of the ultraviolet curable resin by sputtering. (Step S104). FIG. 3G is an enlarged view of a main part of FIG. 3F. The L1 layer reflective film 7 has a light transmittance smaller than that of the L0 layer reflective film 4.

Thereafter, as shown in FIG. 3H, a light transmission layer (also referred to as a cover layer) 8 is formed (step F105). The light transmission layer 8 is formed for the purpose of protecting the optical disk, and laser light used for recording / reproduction of the optical disk is transmitted through the light transmission layer 8 and is recorded on the recording layer including the L0 layer and the L1 layer. Focused. That is, in the optical disk, the side on which the light transmission layer 8 of the disk substrate 1 is formed is the signal reading surface.
The light transmissive layer 8 is formed by dropping an ultraviolet curable resin for the light transmissive layer, spreading it by spin coating, and curing it by irradiating with ultraviolet rays.

Then, as necessary, a hard coat film 9 is formed as shown in FIG. 3I (step F106). The hard coat film 9 is similar to the light transmission layer 8 in order to protect the optical signal from mechanical shock and scratches, and to protect the recording / reproduction quality of information signals from the adhesion of fingerprints during handling by the user. Is formed.
The hard coat layer 9 is formed by dropping an ultraviolet curable resin for the hard coat film 9 on the light transmission layer 8, spreading it by a spin coat method, and curing it by irradiating with ultraviolet rays.

  Subsequently, a moisture-proof film 10 is formed on the surface of the disk substrate 1 that is the surface opposite to the signal reading surface, if necessary (step F107). The moisture barrier film 10 is formed to protect the optical disk from moisture or the like.

Finally, the printing layer 11 subjected to label printing is formed on the moisture-proof film 10 (Step F108).
Through the above steps, an optical disc having two recording layers is completed.

  The present invention is carried out in the process indicated by Step F103 in the above-described optical disk manufacturing method. This will be described in detail below.

[First Embodiment]
FIG. 4 is a schematic configuration diagram of the vacuum transfer apparatus according to the first embodiment of the present invention.

  As shown in FIG. 4, the vacuum transfer apparatus 2 according to this embodiment includes a main vacuum chamber 40 and a preliminary vacuum chamber 41. Inside the main vacuum chamber 40, there is a transfer table 25 as a transfer unit between vacuum chambers rotatably installed. The main vacuum chamber 40 is separated from the upper main vacuum chamber 40a by the transfer table 25 as a boundary. The main vacuum chamber 40b is divided. The vacuum transfer device 2 also includes a substrate transport unit 20 for loading / unloading the disk substrate to / from the vacuum transfer device 2 and a transfer unit 30 for transferring a concavo-convex pattern onto the disk substrate.

  The main vacuum chamber 40 is a space where transfer is actually performed using a stamper, and is a relatively wide space. A vacuum pump 36 is connected to the upper main vacuum chamber 40a and the lower main vacuum chamber 40b of the main vacuum chamber 40 via vacuum valves 37a and 37b, respectively. A gas generator 61 is connected to the lower main vacuum chamber 40b via a pressurizing valve 63 and a flow meter 62. An inert gas of nitrogen is generated from the gas generator 61 of the present embodiment.

  The preliminary vacuum chamber 41 is a space through which a disk substrate passes when a desired disk substrate is carried in and out of the vacuum transfer apparatus 2. The preliminary vacuum chamber 41 is a very narrow space compared to the main vacuum chamber 40. A vacuum pump 22 is connected to the preliminary vacuum chamber 41 via a vacuum valve 23. An air release valve 24 is also connected to the preliminary vacuum chamber 41.

  The substrate transport unit 20 transports the disk substrate from the previous process to the preliminary vacuum chamber 41 of the vacuum transfer apparatus 2 by a mechanism (not shown), and transports the disk substrate taken out from the preliminary vacuum chamber 41 to the next process. is there. The substrate transfer unit 20 is positioned above the preliminary vacuum chamber 41 during the process operation of the vacuum transfer device 2. The substrate transport unit 20 is connected to an opening / closing motor 21, and the cylinder portion is driven by the opening / closing motor 21, so that the part that holds the disk substrate moves up and down with respect to the preliminary vacuum chamber 41. . In particular, when the substrate transfer unit 20 is lowered to a position in contact with the upper surface side of the preliminary vacuum chamber 41, the substrate transfer unit 20 itself becomes a wall surface on the upper surface side for forming the sealed space of the preliminary vacuum chamber 41. Also works.

  The transfer table 25 is for transferring the disk substrate carried in via the preliminary vacuum chamber 41 to a position in the main vacuum chamber 40 where the transfer process is performed. The transport table 25 is supported at the center of the transport table 25 by a support shaft 29a and is rotated by a transport motor 29 connected to the support shaft 29a.

  FIG. 5 shows a schematic configuration when the transfer table 25 is viewed from above. The transport table 25 has two holes Ha and Hb at positions that are point-symmetric with respect to the center position of the transport table 25. The holes Ha and Hb are provided so as to have an outer diameter larger than the outer diameter of the disk substrate.

On the transfer table 25, holding tables 26A and 26B are formed so as to close the holes Ha and Hb, respectively. In the state of FIG. 4, the holding table 26 </ b> A is positioned below the preliminary vacuum chamber 41 on the transfer table 25, while the holding table 26 </ b> B is also positioned below the transfer unit 30 on the transfer table 25. .
The structural portion including the left half of the preliminary vacuum chamber 41 and the main vacuum chamber 40 as the left side in FIG. 4 is hereinafter referred to as “preliminary vacuum chamber side”, and the right side of the main vacuum chamber 41 as the right side in FIG. The structure part including the half is hereinafter referred to as “transfer part side”. In the following description, the side of the holding tables 26A and 26b on which the disk substrate is held is the upper surface, and the opposite surface is the lower surface.

  A cover component 60 is formed on the edge of the outer peripheral portion of the transfer table 25. The cover component 60 is provided so as to close a gap formed between the outer peripheral portion of the transfer table 25 and the side wall of the main vacuum chamber 40. The upper space closed by the cover part 60, that is, the space on the side where the holding tables 26A and 26B are formed is the upper main vacuum chamber 40a, and the space on the opposite side is the lower main vacuum chamber. 40b. The cover component 60 is not configured to prevent gas from passing back and forth between the upper main vacuum chamber 40a and the lower main vacuum chamber 40b, so that slight gas movement is possible. It is composed.

  The transfer motor 29 rotates the transfer table 25 by 180 ° during substrate transfer. Each time the transport table 25 rotates 180 °, the positions of the holding tables 26A and 26B are alternately switched between the preliminary vacuum chamber side and the transfer unit side.

At the center of the upper surface of the holding tables 26A and 26B, a convex portion is formed into which the center hole of the disk substrate is fitted.
Further, a flange 66a is formed on the outer peripheral portion of the upper surface of the holding tables 26A and 26B. And the conveyance table 25 and the collar part 66a of holding | maintenance table 26A, 26B are connected by the elastic member 64 which can be expanded-contracted so that it may each surround the hole parts Ha and Hb.
In addition, a stepped portion 66b is formed on the lower surface of the holding tables 26A and 26B on the outer periphery of the holes Ha and Hb. A holding table vertical movement unit 27 is disposed below the hole Ha located on the auxiliary vacuum chamber side of the transfer table 25. The holding table up / down moving unit 27 is connected to a table lifting / lowering motor 28.

The holding table up-and-down moving unit 27 passes through the hole Ha, contacts the stepped portion 66b of the holding table 26A, and pushes up the holding table 26A from the transfer table 25 toward the preliminary vacuum chamber 41. In this case, the holding table 26 </ b> A is pushed up to a state in contact with the preliminary vacuum chamber 41. In a state where the holding table 26 </ b> A is pushed up to a position in contact with the lower surface of the preliminary vacuum chamber 41, the holding table 26 </ b> A itself also functions as a lower wall surface for forming the sealed space of the preliminary vacuum chamber 41.
When the holding table 26B is on the preliminary vacuum chamber 41 side, the holding table vertical movement unit 27 passes through the hole Hb and comes into contact with the holding table 26B, so that the holding table 26B is moved up and down.
The center of the lower surface of the holding table 26 </ b> A (or 26 </ b> B) and the surface of the holding table vertical movement unit 27 do not contact the stepped portion 66 b.
Further, air and gas are not exchanged between the inner side of the elastic member 64 and the outer side of the elastic member 64, so that airtightness is maintained.

The holding tables 26 </ b> A and 26 </ b> B are respectively inserted into shaft portions 25 a and 25 b that are provided so as to project from the transport table 25. The shaft portions 25a and 25b serve as guide shafts when the holding tables 26A and 26B move up and down with respect to the transport table 25.
The holding tables 26A and 26B are made of a material that transmits ultraviolet rays. An example of a material constituting the holding tables 26A and 26B is quartz glass. In the present embodiment, a light transmissive silicon mat 65 is placed on the glass members constituting the holding tables 26A and 26B. The silicon mat 65 is provided to absorb slight irregularities on the holding tables 26A and 26B and the contact surface of the disk substrate 1 placed on the holding tables 26A and 26B.

  The transfer unit 30 includes a stamper holder 32 that holds a desired stamper at the tip, a holder elevating unit 33 for elevating the stamper holder 32, and a transfer motor 31 for driving the holder elevating unit 33. Composed.

  The stamper holder 32 holds the stamper 50 in the upper main vacuum chamber 40a with the transfer surface facing downward. As described above, the stamper used in this embodiment is the L1 layer stamper 50 on which the transfer surface of the L1 pit pattern constituting the L1 layer is formed, and may be a metal stamper such as Ni.

  The holder lifting / lowering unit 33 is attached above the stamper holder 32 and is configured to be lifted / lowered by driving the transfer motor 31. By raising and lowering the holder lifting and lowering portion 33, the L1 layer stamper 50 held at the tip of the stamper holder 32 is lowered to a position where it is pressed against the disk substrate placed on the holding table 26B (or 26A). It rises to a position away from the substrate, for example, the position shown in FIG.

  Further, the stamper holder 32 has a protruding pin 34. The protrusion pin 34 is moved downward by driving a pin lifting motor 35 connected to the protrusion pin 34, and presses the disk substrate to which the L1 layer stamper 50 is pressure-bonded against the holding table 26B (or 26A) side. That is, when the protrusion pin 34 is lowered, the protrusion pin 34 passes through the center hole portion of the L1 layer stamper 50 and works to press the periphery of the center hole of the disk substrate held by the holding table 26B. is there. Further, an air flow such as nitrogen gas flows in the direction of the disk substrate from around the protrusion pin 34.

  In the main vacuum chamber 40, an ultraviolet irradiation unit 38 is provided below the transfer unit 30 side where the transfer unit 30 is arranged as described above. The ultraviolet irradiation unit 38 applies ultraviolet light to the disk substrate held by the holding table 26B (or 26A) on the transfer unit 30 side via the hole Hb (or Ha) and the holding table 26B (or 26A) of the transport table 25. Is irradiated.

[Vacuum transfer method]
A vacuum transfer method using the vacuum transfer apparatus 2 having the above configuration will be described with reference to FIGS. In this embodiment, the disk substrate 1 carried into the vacuum transfer apparatus 2 is formed on the surface of the L0 layer reflective film 4 after the L0 pit pattern 3 to be the L0 layer is formed as shown in FIG. 2C. This is a disk substrate 1 in a state where an uncured ultraviolet curable resin is spread by spin coating. This ultraviolet curable resin is a resin that becomes the spacer layer 5. Further, the disk substrate 1 unloaded from the vacuum transfer device 2 through the steps in the vacuum transfer device 2 is in a state where a spacer layer (intermediate layer) 5 and an L1 pit pattern are formed as shown in the figure.

  FIG. 6 shows a flowchart as a process performed on the preliminary vacuum chamber side and a process performed on the transfer unit side. Note that the steps F201 to F209 on the preliminary vacuum chamber side and the steps F302 to F305 on the transfer unit side are simultaneously performed in parallel on the disk substrate 1 that is sequentially loaded. The process proceeds according to the procedure indicated by the double arrow. That is, the procedure is step F201 →... F206 → F302 →... → F305 → F207 →.

In the description of the present embodiment, each step as a flow from loading to unloading of one disk substrate 1A along a double line arrow will be described with reference to FIG. During this time, a parallel process is also performed with the next disk substrate 1B being carried in, which will be described after the description of a series of processes for the disk substrate 1A.
Each step in FIG. 6 is labeled with the corresponding figure number in FIGS.

  First, preparation before operation for operating the vacuum transfer apparatus 2 of the present embodiment is performed. The substrate transfer unit 20 in a state where the disk substrate 1A is not held is lowered to the auxiliary vacuum chamber side, and the holding table 26A is raised to seal the auxiliary vacuum chamber 41. The sealed preliminary vacuum chamber 41, the upper main vacuum chamber 40a and the lower main vacuum chamber 40b are evacuated by opening the vacuum valves 23, 37a and 37b and evacuating them with the vacuum pumps 22 and 36. To do. After the upper main vacuum chamber 40a and the lower main vacuum chamber 40b reach a specified pressure, for example, 0.1 Pa, the vacuum valve 37b on the lower main vacuum chamber 40b side is closed, and then the pressure valve 63 open. Then, an inert gas controlled to a constant amount per unit time is always injected into the lower main vacuum chamber 40b by the flow meter 62. By doing so, the lower main vacuum chamber 40a can always maintain a high pressure state between the upper main vacuum chamber 40a and the lower main vacuum chamber 40b. The evacuation on the upper main vacuum chamber 40a side and the injection of the inert gas into the lower main vacuum chamber 40b side are continuously or intermittently performed during the operation period of the vacuum transfer apparatus 2 thereafter.

  In this embodiment, nitrogen gas is used as the inert gas. However, the gas injected into the lower main vacuum chamber 40b is not limited to this, and may be an example of injecting air. Then, by injecting an inert gas into the lower main vacuum chamber 40b, the pressure in the lower main vacuum chamber 40b becomes higher than the pressure in the upper main vacuum chamber 40a.

A cover component 60 provided on the outer peripheral portion of the transfer table 25 so as to cover a gap between the outer peripheral portion of the transfer table 25 and the side wall of the main vacuum chamber 40 includes an upper main vacuum chamber 40a and a lower main vacuum. The chamber 40b is not completely sealed, and there is a slight gap. Since the lower main vacuum chamber 40b has a higher pressure than the upper main vacuum chamber 40a, the inert gas injected into the lower main vacuum chamber 40b passes through the slight gap into the upper main vacuum chamber 40a. The air is exhausted by the vacuum pump 36. Thereby, in the main vacuum chamber 40, an air flow is forcibly generated from the lower main vacuum chamber 40b side to the upper main vacuum chamber 40a side.
The airflow generated in the main vacuum chamber 40 is generated while the apparatus is operating. After the above pre-operation preparation, the transfer process is performed. Below, a transfer process is demonstrated.

  A disk substrate 1A shown in FIG. 7 and thereafter is assumed to be a disk substrate that is first loaded after the vacuum transfer device 2 is operated. Further, it is assumed that the disk substrate 1B shown in FIG. 13 and subsequent figures is a disk substrate that is secondly carried into the vacuum transfer device 2.

First, the substrate transport unit 20 transports the disk substrate 1A coated with the uncured ultraviolet curable resin in the previous process to the upper side of the preliminary vacuum chamber 41 (step F201). Here, as shown in FIG. 7, a certain disk substrate 1 </ b> A is transported above the preliminary vacuum chamber 41 from the previous process. At this time, the substrate transport unit 20 transports the disk substrate 1A while holding the surface on which the ultraviolet curable resin is applied facing upward.
At this time, the holding table 26 </ b> A is raised by the holding table vertical movement unit 27. The holding table up-and-down moving portion 27 passes through the hole Ha and contacts the stepped portion 66b formed on the lower surface side of the holding table 26A, so that the holding table 26A is pushed up toward the preliminary vacuum chamber 41. . For this reason, the lower surface of the holding table 26 </ b> A other than the stepped portion 66 b is not in direct contact with the holding table vertical movement unit 27. Further, the holding table 26 </ b> A is raised to a position where the lower side wall surface of the preliminary vacuum chamber 41 is formed by the holding table vertical movement unit 27.

Next, the disk substrate 1A is transferred into the preliminary vacuum chamber 41 (step F202). Here, as shown in FIG. 8, the substrate transport unit 20 is lowered by the opening / closing motor 21, whereby the disk substrate 1 </ b> A held by the substrate transport unit 20 enters the internal space of the preliminary vacuum chamber 41. .
At this time, the substrate transfer unit 20 is lowered to a position in contact with the upper surface side of the preliminary vacuum chamber 41, and the substrate transfer unit 20 itself constitutes the upper side wall surface of the preliminary vacuum chamber 41. Then, the upper and lower surfaces of the preliminary vacuum chamber 41 are closed by the holding table 26 </ b> A and the substrate transfer unit 20. Thereby, the preliminary vacuum chamber 41 becomes a sealed space.
At this time, the atmosphere release valve 24 is opened.

  Next, the disk substrate 1A is transferred from the substrate transport unit 20 to the holding table 26A (step F203). As shown in FIG. 8, in a state where the substrate transport unit 20 is lowered, the disk substrate 1A is placed on the upper surface of the raised holding table 26A. Therefore, when the substrate transport unit 20 releases the grip of the disk substrate 1A, the disk substrate 1A is delivered to the holding table 26A.

Next, the preliminary vacuum chamber 41 is evacuated (step F204). First, the air release valve 24 is closed, the preliminary vacuum chamber 41 is completely sealed, the vacuum valve 23 is opened, and the vacuum pump 22 performs evacuation.
When the preliminary vacuum chamber 41 reaches a predetermined degree of vacuum, for example, about 50 Pa, by vacuuming, the holding table 26A is lowered and the disk substrate 1A is transported to the upper main vacuum chamber 40a (step F205). That is, as shown in FIG. 9, the disk substrate 1A placed on the holding table 26A enters the upper main vacuum chamber 40a. The holding table 26 </ b> A itself is placed on the upper surface of the transfer table 25.

Next, the disk substrate 1A is transported to the transfer unit side together with the holding table 26A (step F206). Here, the conveyance table 25 is rotated by 180 ° by the conveyance motor 29, and the holding table 26A and the disk substrate 1A are moved from the state of FIG. 9 to the state of FIG. 10 toward the transfer unit in the upper main vacuum chamber 40a. .
In this state, steps S302 and F302 and subsequent steps are executed for the disk substrate 1A as a process on the transfer unit side.

  First, a stamper is pressed against the uncured ultraviolet curable resin layer of the disk substrate 1A to transfer a desired uneven pattern (step F302). In this embodiment, an L1 layer stamper 50 is used as a stamper and a desired L1 pit pattern is transferred. Here, as shown in FIG. 12, the holder lifting / lowering portion 33 is lowered by the transfer motor 31, whereby the L1 layer stamper 50 held by the stamper holder 32 is lowered, and the ultraviolet curable resin layer of the disk substrate 1A is lowered. Pressed against.

  Next, the ultraviolet curable resin is cured by irradiating the ultraviolet curable resin with ultraviolet rays for a certain period of time while the L1 layer stamper 50 is pressed against the ultraviolet curable resin layer (step F303). Here, as shown in FIG. 13, with the L1 layer stamper 50 pressed against the disk substrate 1A, ultraviolet rays are irradiated from the ultraviolet irradiation unit 38 configured on the lower main vacuum chamber 40b side. The ultraviolet light passes through the hole Ha and the holding table 36A made of a material that transmits ultraviolet light, and further passes through the disk substrate 1A made of transparent polycarbonate, and reaches the ultraviolet curable resin applied to the surface of the disk substrate 1A. The curable resin is cured.

  In step F303, the L1 layer stamper 50 and the disk substrate 1A are lifted from the holding table 26A in a state where the L1 layer stamper 50 and the disk substrate 1A are in close contact, and the disk substrate 1A is brought into a non-contact state with the holding table 26A. Irradiation may be performed.

Once the ultraviolet curable resin is cured, the L1 layer stamper 50 is then peeled from the disk substrate 1A (step F304). Here, as shown in FIG. 14, the protrusion pin 34 is lowered by the pin lifting motor 35 so as to pass through the center hole of the L1 layer stamper 50 and press the periphery of the center hole of the disk substrate 1A with the protrusion pin 34. To do. Further, a peeling air flow is emitted from the protruding pin 34 to assist the peeling of the L1 layer stamper 50. By emitting the airflow, a gas intervenes between the L1 layer stamper 50 and the disk substrate 1A, and it becomes easy to peel off. In addition, by flowing an air flow such as nitrogen gas, the disk substrate 1A or the L1 layer stamper 50 is damaged by discharge due to static electricity generated when the L1 layer stamper 50 and the disk substrate 1A are peeled off in a vacuum. Can be prevented.
In this state, the L1 layer stamper 50 is peeled off from the disk substrate 1A by raising the holder elevating part 33 by the transfer motor 31 and raising the stamper holder 32.

Next, the disk substrate 1A is transported to the preliminary vacuum chamber 41 side (step F305).
While the above steps F302 → F303 → F304 are being performed on the transfer unit side, steps F207 → F208 → F209 → F201 → F202 → F203 → F204 → F205 are performed on the preliminary vacuum chamber 41 side. As will be described later, when the disk substrate 1A is to be transported to the auxiliary vacuum chamber side in step F305, the next disk substrate 1B is placed on the holding table 26B as shown in FIG. It has become.
From this state, in step F305, the transfer table 25 is rotated 180 ° by the transfer motor 29, and the holding table 26A and the disk substrate 1A are placed in the main vacuum chamber 40 in the preliminary vacuum chamber as shown in FIG. Moved to the side. At the same time, the next disk substrate 1B is moved to the transfer section side in the main vacuum chamber 40 together with the holding table 26B.

  Looking at the disk substrate 1A, the disk substrate 1A is subsequently transferred to the preliminary vacuum chamber 41 (step F207). Here, as shown in FIG. 18, when the holding table vertical movement unit 27 is raised, the holding table 26 </ b> A on which the disk substrate 1 </ b> A is placed is lifted, and the disk substrate 1 </ b> A is placed in the preliminary vacuum chamber 41. At this time, the holding table 26 </ b> A is in a state of constituting the lower surface side wall surface of the preliminary vacuum chamber 41. As shown in FIG. 18, the substrate transport unit 20 is in a state of constituting the upper side wall surface of the preliminary vacuum chamber 41, and the preliminary vacuum chamber 41 is sealed.

  In this state, the atmosphere release valve 24 is opened, and the preliminary vacuum chamber 41 is opened to the atmosphere (step F208). Next, the substrate transfer unit 20 holds the disk substrate 1A, and the opening / closing motor 21 raises the substrate transfer unit 20 as shown in FIG. 19 (step F209). Thereafter, the disk substrate 1A is transported to the next step.

As described above, the disc substrate 1A that is unloaded after finishing a series of steps in the vacuum transfer apparatus 2 is already in the state in which the spacer layer 5 and the L1 pit pattern 6 are formed as shown in FIG. 3E. Yes.
With regard to the disk substrate 1A, the spacer layer 5 and L1 layer forming process as step F103 in FIG. 1 is completed in the above process, and then the process proceeds to the process after step F104 in FIG. 1 as described above. An optical disc is manufactured.

  When attention is paid to one disk substrate 1A, the above steps are performed. Here, when the next disk substrate 1B is carried in, the steps are performed in parallel on the preliminary vacuum chamber side and the transfer unit side. Explain what will be done.

As described above, it is assumed that the disk substrate 1A is the first one from the start of operation. FIG. 10 shows a state in which steps F201 to F206 are performed on the disk substrate 1A and the disk substrate 1A is conveyed to the transfer unit side.
Here, steps F302, F303, and F304 are performed on the transfer unit side as described above, and in parallel with this, operations on and after step F207 are performed on the preliminary vacuum chamber side.

  First, as shown in FIG. 11, the holding table up-and-down moving unit 27 is lifted to lift the holding table 26 </ b> B transported to the auxiliary vacuum chamber side, and the holding table 26 </ b> B constitutes the lower side wall surface in the auxiliary vacuum chamber 41. (Step F207). The substrate transfer unit 20 is in a state of continuously forming the upper side wall surface of the preliminary vacuum chamber 41 from the time of Step F202 (FIG. 9).

  Next, the atmosphere release valve 24 is opened to release the preliminary vacuum chamber 41 to the atmosphere (step F208). Then, the substrate transport unit 20 is raised by the opening / closing motor 21 as shown in FIG. 19 (step F209).

Subsequently, the process returns to Step F201 on the preliminary vacuum chamber side.
First, the substrate transport unit 20 transports the next disk substrate 1B, to which the uncured ultraviolet curable resin has been applied in the previous process, above the preliminary vacuum chamber 41 as shown in FIG. 13 (step F201).

  Next, as shown in FIG. 14, the substrate transport unit 20 is lowered by the opening / closing motor 21, whereby the disk substrate 1 </ b> B held by the substrate transport unit 20 is transported into the preliminary vacuum chamber 41 (step). F202). Thereafter, the disk substrate 1B is transferred from the substrate transport unit 20 to the holding table 26B (step F203).

  Next, in the state shown in FIG. 15, the preliminary vacuum chamber 41 is evacuated again (step F204). That is, the air release valve 24 is closed and the preliminary vacuum chamber 41 is completely sealed, and then the vacuum valve 23 is opened and the vacuum pump 22 performs evacuation.

  When the preliminary vacuum chamber 41 reaches a predetermined degree of vacuum (for example, about 50 Pa) by evacuation, next, as shown in FIG. 16, the holding table 26B is lowered and the disk substrate 1B is transferred to the upper main vacuum chamber 40a. (Step F205).

  As described above, the state shown in FIG. 16 is a stage where the stamper peeling process for the disk substrate 1B has been completed on the transfer unit side.

Next, step F206 is performed on the preliminary vacuum chamber side, and step F305 is performed on the transfer unit side. This is one operation in which the transport table 25 is rotated 180 ° by the transport motor 29. Is executed.
Thus, as described above, the disk substrate 1A is returned to the preliminary vacuum chamber side, and the next disk substrate 1B is sent to the transfer portion side. That is, the state shown in FIG.
Thereafter, as described above, the disk substrate 1A is sent to the preliminary vacuum chamber 41 as shown in FIG. 18, and after the preliminary vacuum chamber 41 is opened to the atmosphere, it is unloaded by the substrate transfer unit 20 as shown in FIG. However, at this time, on the transfer portion side, the L1 layer stamper 50 is pressed against the disk substrate 1B in step F302 as shown in FIG.

After that, on the transfer portion side, the ultraviolet irradiation process of Step F303 and the stamper peeling process of Step F304 are performed on the disk substrate 1B.
Further, although not shown in the drawing, the next disk substrate is further carried on the preliminary vacuum chamber side, and steps F201 to F205 are performed.

  In the vacuum transfer device 2 of the present embodiment, every time the disk substrate 1 is sent from the previous process, the above operation is performed in parallel on the preliminary vacuum chamber side and the transfer unit side.

  In the vacuum transfer apparatus 2 of the present embodiment, a pressure difference can be provided between the lower main vacuum chamber 40b and the upper main vacuum chamber 40a by injecting an inert gas into the lower main vacuum chamber 40b. As a result, an air flow is generated from the lower main vacuum chamber 40b toward the upper main vacuum chamber 40a, and in the upper main vacuum chamber 40a, the volatile components generated from the uncured ultraviolet curable resin and the ultraviolet curable resin Volatile components generated during curing can be prevented from adhering to the holding tables 26A and 26B and the peripheral portion. Further, the main vacuum chamber 40 is divided into an upper main vacuum chamber 40a and a lower main vacuum chamber 40b, and due to a differential pressure between the upper main vacuum chamber 40a and the lower main vacuum chamber 40b, the upper main vacuum chamber 40a. Volatile components generated in the above do not enter the lower main vacuum chamber 40b. Thereby, it is possible to prevent volatile components from adhering to the holding tables 26A and 26B on the side irradiated with ultraviolet rays, and reduce the curing failure of the ultraviolet curable resin spread on the disk substrate 1 in the transfer process. be able to.

  As described above, in the vacuum transfer device 2 and the vacuum transfer method of the present embodiment, the air current is forcibly generated in the main vacuum chamber 40 to generate the ultraviolet curable resin spread on the disk substrate. It is possible to prevent the volatile substance to adhere to the vacuum transfer device 2. This eliminates the need for regular maintenance of the vacuum transfer apparatus 2 that is performed to remove volatile substances. Alternatively, the interval for carrying out regular maintenance can be increased, leading to an improvement in operating rate.

  In the above-described embodiment, the main vacuum chamber 40 is divided into the upper main vacuum chamber 40a and the lower main vacuum chamber 40b, and the pressure in the upper main vacuum chamber 40a and the pressure in the lower main vacuum chamber 40b are changed. Thus, a differential pressure is generated to generate an air flow. The present invention is not limited to such a configuration, and any configuration that can generate a differential pressure and forcibly generate a desired air flow in the main vacuum chamber 40 may be used.

  Further, in this embodiment, by providing the preliminary vacuum chamber 41, release of the atmosphere and evacuation when the disk substrate 1 is carried out / in is performed in the preliminary vacuum chamber 41. Since the preliminary vacuum chamber 41 does not require a relatively large space for performing stamper transfer, it can be formed as a space having a small space volume as illustrated. Similarly, since it is not a space for performing stamper transfer, the degree of vacuum can be set lower than that of the main vacuum chamber 40. For this reason, evacuation in the preliminary vacuum chamber 41 can be performed quickly.

  Further, since the preliminary vacuum chamber 41 and the main vacuum chamber 40 are provided, it is possible to perform simultaneous process operations on the preliminary vacuum chamber side and the transfer unit side. Thereby, in the vacuum transfer apparatus 2 of the present embodiment, a very efficient vacuum transfer process is realized.

In the present embodiment, an example in which the vacuum transfer device 2 is used in the process of forming the L1 layer pit pattern and the spacer layer in the manufacturing process of the read-only two-layer disk is shown. The present invention can be applied even to a manufacturing process of a disc having three or more recording layers.
For example, the vacuum transfer device 2 can perform the same operation as described above in the step of forming pit patterns and spacer layers as the third recording layer and the fourth recording layer on three or more optical discs.
Further, when forming the first recording layer (L0 layer) in a single-layer disc or a multi-layer disc, the vacuum transfer device of the present invention may be used instead of injection molding. For example, a pit pattern as an L0 layer is formed by applying an ultraviolet curable resin to a disk substrate (for example, a glass substrate) having a flat surface and performing the operation of the above-described embodiment with a vacuum transfer device. Is also possible.

  Of course, the concavo-convex pattern may be a groove pattern such as a write-once type or a rewritable type disk, not a pit pattern for forming a read-only disk. In other words, if the stamper used in the vacuum transfer apparatus is a groove transfer stamper, the present invention can be applied to a manufacturing process using a write-once disc or a rewritable disc.

  Further, the present invention can be applied to the manufacture of various discs such as Blu-ray discs, DVD (Digital Versatile Disc) type discs, CD (Compact Disk) type discs, etc. as types of optical discs.

It is a flowchart of the disc manufacturing process of one embodiment concerning the present invention. It is process drawing of the board | substrate on the manufacturing process of one Embodiment which concerns on this invention. It is process drawing of the board | substrate on the manufacturing process of one Embodiment which concerns on this invention. 1 is a schematic configuration diagram of a structure of a vacuum transfer apparatus according to an embodiment of the present invention. It is a schematic block diagram when the conveyance table of the vacuum transfer apparatus of one Embodiment which concerns on this invention is seen from the upper surface. It is a flowchart of the spacer layer and L1 layer formation process using the vacuum transfer device of one embodiment concerning the present invention. It is a schematic block diagram at the time of carrying in of the disc substrate in the vacuum transfer device of one embodiment concerning the present invention. It is a schematic block diagram at the time of carrying in the preliminary | backup vacuum chamber of the disk substrate in the vacuum transfer apparatus of one Embodiment which concerns on this invention. It is a schematic block diagram at the time of conveyance to the main vacuum chamber of the disk substrate in the vacuum transfer apparatus of one embodiment concerning the present invention. It is a schematic block diagram of the state at the time of conveyance to the transfer part side of a disk substrate in the vacuum transfer apparatus of one embodiment concerning the present invention. It is explanatory drawing of the operation | movement by the side of the preliminary | backup vacuum chamber of the vacuum transfer apparatus of one Embodiment which concerns on this invention. It is explanatory drawing of the operation | movement at the time of transcription | transfer of the vacuum transfer apparatus of one Embodiment which concerns on this invention. It is explanatory drawing of the operation | movement at the time of ultraviolet irradiation of the vacuum transfer apparatus of one Embodiment which concerns on this invention. It is explanatory drawing of the operation | movement at the time of stamper peeling of the vacuum transfer apparatus of one Embodiment which concerns on this invention. It is explanatory drawing of the operation | movement at the time of stamper peeling of the vacuum transfer apparatus of one Embodiment which concerns on this invention. It is explanatory drawing of the operation | movement by the side of the preliminary | backup vacuum chamber of the vacuum transfer apparatus of one Embodiment which concerns on this invention. It is explanatory drawing of the disk substrate conveyance of the preliminary | backup vacuum chamber side and transfer part side of the vacuum transfer apparatus of one Embodiment which concerns on this invention. It is explanatory drawing of conveyance to the preliminary | backup vacuum chamber of the disk substrate of the vacuum transfer apparatus of one Embodiment which concerns on this invention. It is explanatory drawing of the state at the time of carrying out the disk substrate of the vacuum transfer apparatus of one Embodiment which concerns on this invention.

Explanation of symbols

  1, 1A, 1B ... Disk substrate, 3 ... L0 pit pattern, 4 ... L0 layer reflective film, 5 ... Spacer layer, 6 ... L1 pit pattern, 7 ... L1 layer reflective film, 8 ... Light Transmission layer, 20 ... substrate transfer part, 22, 36 ... vacuum pump, 23, 37a, 37b ... vacuum valve, 24 ... atmosphere release valve, 25 ... transport table, 26A, 26B ... holding table, 30 ..Transfer section, 32..Stamp holder, 38..Ultraviolet irradiation section, 40..Main vacuum chamber, 40a..Upper main vacuum chamber, 40b..Lower main vacuum chamber, 41..Preliminary vacuum chamber

Claims (8)

A preliminary vacuum chamber that is evacuated by a vacuum suction mechanism and can be opened to the atmosphere by an atmosphere release mechanism;
A main vacuum chamber that is evacuated by a vacuum suction mechanism;
A substrate transfer unit for loading / unloading the disk substrate into / from the preliminary vacuum chamber;
A disk substrate on which an ultraviolet curable resin is spread is placed, and a conveyance unit between the vacuum chambers that conveys the disk substrate between the preliminary vacuum chamber and the main vacuum chamber,
In the main vacuum chamber, a transfer unit that performs a transfer process for transferring a concavo-convex pattern to a disk substrate using a stamper;
An ultraviolet irradiation unit for irradiating the disk substrate placed in the inter-vacuum chamber transfer unit with ultraviolet rays;
A pressure mechanism for injecting a desired gas into the main vacuum chamber to generate a differential pressure in the main vacuum chamber in an operating state;
Including vacuum transfer device. A preliminary vacuum chamber that is evacuated by a vacuum suction mechanism and can be opened to the atmosphere by an atmosphere release mechanism;
A main vacuum chamber that is evacuated by a vacuum suction mechanism;
A substrate transfer unit for loading / unloading the disk substrate into / from the preliminary vacuum chamber;
The main vacuum chamber is divided into an upper main vacuum chamber and a lower main vacuum chamber, and a disk substrate on which an ultraviolet curable resin is spread is placed on the upper main vacuum chamber, and the preliminary vacuum chamber and the An inter-vacuum chamber transport unit that transports the disk substrate to and from the main vacuum chamber;
In the upper main vacuum chamber, a transfer unit that performs a transfer process of transferring a concavo-convex pattern to a disk substrate using a stamper;
An ultraviolet irradiating unit that irradiates the disk substrate placed on the inter-vacuum chamber transport unit through the vacuum chamber transport unit from the lower main vacuum chamber side;
A pressure mechanism for holding the pressure of the lower main vacuum chamber to be higher than the pressure of the upper main vacuum chamber in an operating state;
Including vacuum transfer device.   The vacuum transfer apparatus according to claim 2, further comprising a cover part configured to cover a gap between the outer peripheral portion and a wall surface of the main vacuum chamber on an outer peripheral portion of the inter-vacuum chamber conveying portion.   The disk substrate placed on the inter-vacuum chamber transport section covers a hole provided in the inter-vacuum chamber transport section, on a light-transmitting holding table provided on the upper main vacuum chamber side. The vacuum transfer device according to claim 2, wherein the holding table and the outer peripheral portion of the hole are connected by an elastic member.   The vacuum transfer apparatus according to claim 2, wherein the cover part is configured to allow gas to pass from the lower main vacuum chamber side to the upper main vacuum chamber side.   3. The vacuum transfer device according to claim 2, wherein the pressurizing mechanism includes a gas generating device and a pressurizing valve that injects a desired gas flowing from the gas generating device into the lower main vacuum device.   The vacuum transfer device according to claim 6, wherein the pressurizing mechanism includes a flow meter, and a flow rate of the gas injected into the lower main vacuum device is controlled by the flow meter. Vacuuming the main vacuum chamber,
A step of carrying a disk substrate on which an uncured ultraviolet curable resin layer is formed into a preliminary vacuum chamber;
Placing the disk substrate carried into the preliminary vacuum chamber on a transfer unit between vacuum chambers that divides the main vacuum chamber into an upper vacuum chamber and a lower vacuum chamber;
Evacuating the preliminary vacuum chamber;
Transferring from the preliminary vacuum chamber to the main vacuum chamber;
Injecting a desired gas into the lower main vacuum chamber to make the pressure of the lower main vacuum chamber higher than the pressure of the upper main vacuum chamber;
A step of irradiating the ultraviolet curable resin layer with ultraviolet rays through the vacuum chamber transfer portion from the lower main vacuum chamber side simultaneously with pressing a desired stamper on the ultraviolet curable resin layer;
And a vacuum transfer method.

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