JP3327064B2 - Stamper holding method and substrate forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for holding a stamper for transferring information when a substrate used for an optical disk or the like is formed, and a method for forming a substrate.

[0002]

2. Description of the Related Art Conventionally, substrates for optical disks have been formed by injection molding using synthetic resins such as polycarbonate resins, acrylic resins, and polyolefin resins.

At this time, a stamper provided with grooves for forming information pits and tracks is mounted on a mold to form a substrate. This stamper is generally made of nickel, and the back surface is polished and mirror-finished, and the stamped ring is mechanically held on the mirror surface of the mold or held by vacuum suction. I have. Particularly, holding the stamper by vacuum suction has an advantage that the stamper can be quickly attached and detached. A method of vacuum suctioning the stamper is disclosed in Japanese Patent Application Laid-Open No. 60-201919.

FIG. 8 shows a conventional method for vacuum suction of a stamper.
This will be described with reference to FIG. Reference numeral 101 denotes a stamper, and concentric annular gaps 103 and 1 provided in a fixed mold 102.
04 from the vacuum formed by the vacuum pump 105,
The inner circumference and the outer circumference of the stamper 101 are sucked.

The stamper 101 is mounted on a fixed mold 102.
The stamper 101 is attached to the positioning protrusion 106 provided on the upper side.
The position of the stamper is adjusted by aligning the inner holes of the electromagnetic valve opening / closing circuit 108 with a command from the stamper attaching / detaching circuit 107 while the vacuum pump 105 is operating.
By operating the valve 109 and the valve 110 in this order, the fixed mold 10
Perform the vacuum suction in Step 2. Removal of the stamper 101
Conversely, the electromagnetic valve opening / closing circuit 108 is operated by a command from the stamper attaching / detaching circuit 107, and the valve 110, the valve 109
In this order, the vacuum suction with the fixed mold 102 is completed and performed in the order of the outer periphery and the inner periphery of the stamper 101. Thus, there is one vacuum pump.

The fixed mold 102 is attached to the large plate 111 with bolts or the like. Also, the movable mold 112 is
Like the fixed mold 102, it is attached to the large plate 113 with bolts or the like. In FIG. 8, an abutment method is used in which an outer peripheral ring 114 for defining the outer diameter of a molded product is provided on a movable mold 112.

The movable mold 112 is moved by a hydraulic clamping mechanism 115 connected to the large plate 113. In addition, the movable mold 11 is
A mold clamping force is generated when the fixed mold 2 and the fixed mold 102 are closed.

In the conventional vacuum suction method, the degree of vacuum is monitored by:
The degree of vacuum measured by the vacuum gauge 116 is monitored by the vacuum degree monitoring circuit 117 only at the inner periphery of the stamper 101 having a small vacuum suction area, and when the vacuum degree falls below a specified value, the mold closing stop circuit 1
18 to stop the molding to protect the stamper 101, the fixed mold 102 and the movable mold 112,
The alarm circuit 119 is operated to notify the worker of the abnormality.

[0009]

In the conventional vacuum suction method for a stamper, only one vacuum generating means is required. However, when any of the vacuum suction portions on the back surface of the stamper comes off the mold, the vacuum suction is performed. Since the degree of vacuum is reduced at all locations where the stamper is used, there is a problem that the stamper is detached and damaged.

In particular, since the inner peripheral portion of the stamper is a portion forming a substrate, the area for sucking the stamper is small so that the deformation of the stamper is not transferred, and the force for attracting the stamper is smaller than the outer peripheral portion. Therefore, there is a problem that the inner peripheral portion of the stamper is easily detached from the mold.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a method for holding a stamper using vacuum suction, which makes it difficult for the stamper to be detached from a mold during substrate molding, and a molding system for preventing breakage of the stamper.

[0012]

According to a first method of holding a stamper of the present invention for solving the above-mentioned problems, a plurality of locations on the back surface of the stamper are evacuated using individual vacuum generating means.

According to a second method of holding a stamper of the present invention, at least the inner peripheral portion of the back surface of the stamper is vacuum-sucked at a plurality of locations.

In a first method of forming a substrate according to the present invention, a plurality of locations on the back surface of a stamper are evacuated using a plurality of vacuum generating means, and a vacuum gauge is provided for each vacuum generating means to monitor the degree of vacuum. The operation of closing the mold is stopped when the degree of vacuum in one vacuum gauge falls below a specified degree of vacuum.

Further, the second method of forming a substrate according to the present invention comprises:
Vacuum suction is performed on a plurality of locations on the back surface of the stamper using the same vacuum generating means, and when the mold is opened, the path for vacuum suction on the outer peripheral side of the stamper is closed to maintain a vacuum, and provided at each vacuum suction location. The degree of vacuum is monitored by a vacuum gauge, and the operation of closing the mold is stopped when the degree of vacuum in at least one of the vacuum gauges falls below a specified level.

Further, in the third substrate molding system of the present invention, a plurality of locations on the back surface of the stamper are evacuated using the same vacuum generating means, and the outer peripheral side of the stamper is evacuated when the mold is opened. Closed or switched to the path of vacuum generating means with a lower ultimate vacuum, and monitor the vacuum with a vacuum gauge provided at each vacuum suction point. Then, the operation of closing the mold is stopped.

[0017]

According to the present invention, a plurality of locations on the back surface of the stamper are individually suctioned using a vacuum generating means, so that even if the degree of vacuum is deteriorated at one location, the other vacuum suction locations are not affected. It is hard to come off the mold.

In addition, by vacuum-suctioning at least a plurality of locations on the inner peripheral portion of the back surface of the stamper, the area for attracting the inner peripheral portion of the stamper is increased, the suction force is increased, and the stamper is less likely to come off the mold.

Further, since the degree of vacuum is monitored for each individual vacuum generating means for vacuum-sucking the back surface of the stamper, when the stamper comes off the mold, the operation of closing the mold is always stopped. Is done.

Further, a plurality of locations on the back surface of the stamper are evacuated using the same vacuum generating means, and when the mold is opened,
Vacuum is generated by closing the path where the outer peripheral side of the stamper is vacuum-sucked to maintain the vacuum, or by switching the path where the outer peripheral side of the stamper is vacuum-sucked to the path of vacuum generating means having a lower ultimate vacuum. The number of means can be reduced, and the vacuum generating means capable of generating a high degree of vacuum can be effectively used.

[0021]

An embodiment of the present invention will be described with reference to the drawings. In the following description, a case where an annular flat stamper in which pits and grooves are formed is attached to a fixed mold will be described.

(Embodiment 1) FIG. 1 shows a first embodiment of a stamper holding method according to the present invention.

Reference numeral 1 denotes a stamper, which is attached to a fixed mold 2. The stationary mold 2 has annular gaps 3 and 4, and the stamper 1 is attracted to the stationary mold 2 by drawing a vacuum by vacuum pumps 5 and 6 connected by tubes. That is, a vacuum pump is provided at each location where the stamper 1 is vacuum-sucked. Therefore, even if the degree of vacuum is reduced while vacuum suction is being performed, the other is not affected. Therefore, the stamper 1 is less likely to come off.

The stationary mold 2 has a positioning projection 7.
The positioning is performed by fitting the inner hole of the stamper 1. The method of attaching / detaching the stamper 1 to / from the fixed mold 2 is the same as in the prior art, and a command is issued from the stamper attaching / detaching circuit 8 to the electromagnetic valve opening / closing circuit 9 to open and close the valves 10 and 11.

Next, a method of forming a first substrate according to the present invention will be described. Tubes leading to the annular gaps 3 and 4 provided on the inner and outer circumferences of the stamper 1, respectively,
Vacuum gauges 12 and 13 are provided, and a vacuum degree monitoring circuit 14 monitors whether the degree of vacuum is equal to or more than a specified value. If the value falls below the specified value, a signal is sent to the mold closing / stopping circuit 15 to stop the mold in an open state, and a signal is sent to the alarm circuit 16 to release the stamper 1 from the fixed mold 2. To the operator.

The mold closing / stopping circuit 15 operates on the mold clamping mechanism 17 and, after the mold is opened, the operator confirms an abnormal state and does not operate the mold unless the state is released. The mold clamping mechanism 17 is hydraulically operated, and moves the movable mold 19 via the large plate 18. 20 is also a large plate and has a fixed mold 2
Is attached with bolts or the like. Reference numeral 21 denotes an outer ring, which defines the outer diameter of the molded substrate.

In the present invention, vacuum gauges 12 and 13 are provided at each position where the stamper 1 is vacuum-evacuated, and the degree of vacuum is monitored. Therefore, when the stamper 1 comes off the fixed mold 2, the mold is reliably stopped in an open state, so that the stamper 1, the fixed mold 2 and the movable mold 19 can be prevented from being damaged.

(Embodiment 2) FIG. 2 shows a second embodiment of the stamper holding method according to the present invention. In comparison with the first embodiment, the number of annular gaps for sucking the inner periphery of the stamper 1 is increased to 12 and 24. The annular gaps 12 and 24 have the same center as the stamper 1. The suction position on the inner periphery of the stamper 1 is at a position where a molded substrate is formed. Therefore, the width of the annular gap is 50 μm or less, preferably 40 μm or less in order not to deform the stamper. Further, it is necessary to suck the stamper 1 at the inner periphery in order not to affect the signal portion. As a result, the suction area is small and the force for sucking the stamper 1 is weak, and the stamper 1 may come off the fixed mold 2 on the inner periphery. On the other hand, in the present invention, since a plurality of annular gaps are provided, the area for sucking the inner periphery of the stamper 1 is increased, and the suction force is increased, so that the inner periphery of the stamper 1 is less likely to come off from the fixed mold 2. Become.

On the other hand, the suction at the outer periphery of the stamper 1 can be performed outside the formation of the molded substrate, so that there is no influence of the deformation of the stamper 1 and the suction area can be widened, so that the suction force can be sufficiently increased. .

In the present invention, since a plurality of vacuum generating means are provided and are independent of each other, even if the degree of vacuum is reduced by one vacuum pump, the other one is not affected. Therefore, the stamper 1 is unlikely to come off the fixed mold 2.

(Embodiment 3) FIG. 3 shows a third embodiment of the stamper holding method according to the present invention. In comparison with the first embodiment, an annular gap 22 for vacuum suction is increased on the inner periphery of the stamper 1, and a vacuum valve 23 and a vacuum gauge 24 are newly introduced. Further, as the vacuum generator, Convum 25, 26,
27, and the convum 25, 26, 27
Is led to compressed air. Second Embodiment Because the number of annular gaps for adsorbing the inner periphery of the stamper 1 is increased from one to two.
Similarly, the area for sucking the inner periphery of the stamper 1 increases, and the suction force increases, so that the stamper 1 is less likely to come off the fixed mold 2. Further, since the vacuum systems sucking the stamper 1 have independent vacuum generating means,
Even if the degree of vacuum is reduced at one suction point, the other suction parts are not affected, and the stamper 1 is fixed at the suction point where the degree of vacuum is not reduced because the stamper 1 is to be held in the fixed mold 2. It is difficult for the mold 2 to come off.

In general, when a convum is used, the degree of vacuum fluctuates under the influence of fluctuations in the compressed air pressure. However, in the configuration of the present invention, there is sufficient power to suck the stamper 1 into the fixed mold 2, so that it is sufficiently practical. It is.

(Embodiment 4) FIG. 4 shows a second embodiment of the method of forming a substrate according to the present invention. Compared to FIG. 1, there is one vacuum pump, and a molding cycle monitor circuit 28 is newly connected to the electromagnetic valve opening / closing circuit 9. Here, the valve 10
(A) and the operation at the time of molding the valve 11 (B) will be described with reference to FIG. First, the molding cycle monitor circuit 28 detects the opening time of the mold, and closes the valve 11 (B) connected to the annular gap 4 sucking the outer periphery of the stamper 1 for this period. The molding cycle monitor circuit 28 includes the movable mold 19
The opening start signal and the opening completion signal may be monitored.
The valve 10 (A) connected to the annular gap 3 sucking the inner periphery of the stamper 1 remains open. Therefore, the vacuum pump 5 only sucks the inner periphery of the stamper 1 when the mold is opened. The force acting on the stamper 1 in the direction of peeling from the fixed mold 2 is applied when the formed substrate and the stamper 1 are peeled off, that is, when the fixed mold 2 and the movable mold 19 are opened. Therefore, the fixed mold 2 is attached to the stamper 1.
Stamper 1 with a small suction area when a force is applied to peel it off
Is sucked by the vacuum pump 5 alone. Further, the vacuum suction system on the outer periphery of the stamper 1 has a larger suction area than the inner periphery, so that the suction force is strong, and
Vacuum is maintained for a while during the operation of opening the mold to close (B). Therefore, the stamper 1 is less likely to come off the fixed mold 2. This configuration has the advantage that the number of vacuum generating means can be reduced.

Also in this embodiment, vacuum gauges 12 and 13 are provided in the respective inner and outer systems for sucking the stamper, and it is confirmed by the vacuum degree monitoring circuit 14 that the values are equal to or larger than a specified value. When the suction force is weakened, the mold closing stop circuit 15 and the alarm circuit 16 operate, so that the stamper 1, the fixed mold 2, and the movable mold 19 are not likely to be damaged.

Embodiment 5 FIG. 6 shows a third embodiment of the substrate forming method of the present invention. In contrast to the second embodiment, a convum 30 is connected to the outer peripheral suction system of the stamper 1 via a valve 29 (C). And this valve 29
(C) is also connected to the electromagnetic valve opening / closing circuit 9.

FIG. 7 shows how the valve is opened and closed. First,
The molding cycle monitor circuit 28 detects when the mold opens, and when the mold opens, the valve 11 (B) is closed and the valve 29 (C) is opened. Valve 10 (A) remains open. As a result, when the mold is opened, the inner periphery of the stamper 1 is sucked by the vacuum pump 5 and the outer periphery is
Aspirate. In other cases, the vacuum pump 5 suctions the inner and outer peripheries of the stamper 1. As a result, the inner periphery having a small area for sucking the stamper 1 is always sucked by the vacuum pump 5, which has a strong suction force and is stable. At the outer periphery of the stamper 1, most of the time is sucked by the vacuum pump 5, which has a strong suction force and is stable, so that the degree of vacuum does not decrease even when the mold is opened. Therefore, the stamper 1 is less likely to come off the fixed mold 2.

Also in this embodiment, the vacuum gauges 12 and 13 are provided in the respective inner and outer systems for sucking the stamper, and it is confirmed by the vacuum degree monitoring circuit 14 that the values are equal to or larger than a specified value. When the suction force is weakened, the mold closing stop circuit 15 and the alarm circuit 16 operate, so that the stamper 1, the fixed mold 2, and the movable mold 19 are not likely to be damaged.

In this embodiment, the vacuum pump for suctioning the outer periphery of the stamper 1 determines whether the vacuum pump 5
And the vacuum 30 are switched, but a vacuum gauge for measuring the vacuum of the vacuum 30 is provided, and compared with the vacuum at the vacuum gauge 13 indicating the vacuum of the outer periphery, the vacuum by the vacuum 30 becomes the same. Then, it may be switched to the convum 30.

In this embodiment, the outer peripheral ring 21 is the stamper 1
Although the case where the outer ring 21 is attached to the mold on which the stamper 1 is adsorbed may be attached, it is needless to say that the outer ring 21 may be attached to the mold on which the stamper 1 is adsorbed. Even when the outer peripheral ring 21 and the stamper 1 are closest to each other, there is a clearance for gas escape, and there is no contact. Therefore, the outer ring 2
Even when the stamper 1 is mounted on the mold on the side where the stamper 1 is located, the suction of the outer periphery of the stamper 1 suppresses the vibration in the direction of removing the stamper 1 from the mold, and the stamper 1 It is hard to come off. Further, in this embodiment, the case where the stamper 1 is on the fixed mold 2 side is shown, but the case where the stamper 1 is on the movable mold 19 side may be used.

[0040]

According to the present invention, since a plurality of locations on the back surface of the stamper are evacuated using individual vacuum generating means, even if the degree of vacuum is deteriorated at one location, the other evacuated locations are not affected. The stamper is hard to come off the mold.

Further, by vacuum-suctioning at least a plurality of locations on the inner peripheral portion of the back surface of the stamper, the area for attracting the inner peripheral portion of the stamper is increased, the suction force is increased, and the stamper is less likely to come off the mold.

Furthermore, since the degree of vacuum is monitored for each individual vacuum generating means for vacuum-sucking the back surface of the stamper, when the stamper comes off the mold, the operation of closing the mold always stops. Is prevented.

Further, a plurality of locations on the back surface of the stamper are vacuum-suctioned using the same vacuum generating means, and when the mold is opened,
Vacuum is generated by closing the path where the outer peripheral side of the stamper is vacuum-sucked to maintain the vacuum, or by switching the path where the outer peripheral side of the stamper is vacuum-sucked to the path of vacuum generating means having a lower ultimate vacuum. The number of means can be reduced, and the vacuum generating means capable of generating a high degree of vacuum can be effectively used.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a stamper holding method and a molding system according to the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the stamper holding method of the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of a stamper holding method according to the present invention.

FIG. 4 is a configuration diagram showing a second embodiment of the substrate forming method of the present invention.

FIG. 5 is a view showing a valve operation of a second embodiment of the substrate forming method of the present invention.

FIG. 6 is a configuration diagram showing a third embodiment of the substrate forming method of the present invention.

FIG. 7 is a view showing a valve operation of a third embodiment of the substrate forming method of the present invention.

FIG. 8 is a configuration diagram showing a conventional stamper holding method and a substrate molding method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 stamper 2 fixed mold 3, 4, 22 annular gap 5, 6 vacuum pump 8 stamper attaching / detaching circuit 9 electromagnetic valve opening / closing circuit 10, 11, 23, 29 valve 12, 13, 24 vacuum gauge 14 vacuum monitoring circuit 15 mold Closing stop circuit 19 Movable mold

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-142617 (JP, A) JP-A-59-7023 (JP, A) JP-A-7-29225 (JP, A) 212751 (JP, A) Japanese Utility Model 1-127720 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 33/00-33/76 B29C 45/00-45/84 G11B 7/00-7/30

Claims (5)

(57) [Claims] A method for holding a stamper, wherein a plurality of individual vacuum generating means are used to suction the back surface of the stamper at a plurality of locations. 2. A plurality of locations on the back surface of the stamper are evacuated using a plurality of vacuum generating means, and a vacuum gauge is provided for each of the vacuum generating means to monitor the degree of vacuum. A method of forming a substrate that stops the operation of closing the mold when the temperature deteriorates . 3. A plurality of locations on the back surface of the stamper are evacuated using individual vacuum generating means, and a vacuum gauge is provided for each of the vacuum generating means to monitor the degree of vacuum. A method of forming a substrate that stops the operation of closing the mold when the temperature deteriorates . 4. The vacuum suction means for vacuuming a plurality of locations on the back surface of the stamper using the same vacuum generating means, and closing a path for vacuuming the outer peripheral side of the stamper when the mold is opened. A method of forming a substrate, wherein the degree of vacuum is monitored by a provided vacuum gauge, and the operation of closing a mold is stopped when the degree of vacuum in at least one vacuum gauge becomes lower than a prescribed degree of vacuum . 5. A vacuum generating means having a low degree of ultimate vacuum through a path in which a plurality of locations on the back surface of the stamper are evacuated using the same vacuum generating means, and the outer peripheral side of the stamper is evacuated when the mold is opened. The method of forming a substrate in which the degree of vacuum is monitored by a vacuum gauge provided for each vacuum suction point, and the operation of closing the mold is stopped when the degree of vacuum becomes worse than a prescribed degree of vacuum in at least one vacuum gauge.