JP3861013B2 - Method for controlling traveling in a vacuum chamber of a transport carriage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum indoor travelling control method of a carrier carriage of high through-put capable of speedily and smoothly carry a base plate without giving fatal vibration and impact to the base plate without dropping speed of the carriage in a vacuum processing chamber. <P>SOLUTION: A following servo motor is started at low torque in timing immediately before engagement of a following pinion with a rack in a state where a precedent pinion is engaged with the rack and driving force is transmitted to the carrier carriage, driving of a precedent servo motor is changed from high torque over to low torque in timing at an instant of the following pinion engaged with the rack, and simultaneously, driving of the following servo motor is changed from low torque over to high torque, the vacuum indoor travelling control method of the carrier carriage to carry the base plate held on the carrier carriage to a plurality of the vacuum processing chambers by transmitting driving force by engaging a plurality of the pinions arranged with specified intervals along a track with the rack of the carrier carriage. <P>COPYRIGHT: (C)2003,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a traveling control method for a transport carriage of a transport carriage that transports a glass substrate in a vacuum processing chamber for performing CVD film formation or the like.
[0002]
[Prior art]
Since the vacuum processing chamber that performs processing such as plasma CVD, sputtering, and dry etching on the substrate is surrounded by the outer wall of the chamber in order to maintain hermeticity, it is impossible to control the traveling of the conveyance carriage with the naked eye. The method for transmitting the driving force into the processing chamber is greatly restricted.
[0003]
For example, since the vacuum processing chamber is partitioned by a gate valve, a timing belt drive mechanism cannot be employed for synchronization in vacuum. If the timing belt drive mechanism is installed in the atmosphere, it cannot be installed due to space limitations of the frame on which the vacuum processing chamber is placed, and the mechanism becomes complicated when vacuum processing chambers with complicated shapes are connected to each other. Therefore, its practical application is very difficult.
[0004]
In order to transport a board safely and smoothly so that a fatal impact or vibration is not transmitted to the board under such a special environment, several traveling control methods for the transport carriage have been proposed.
[0005]
For example, in Japanese Patent Application Laid-Open No. 10-158835, in order to reduce the impact at the moment when the rack of the carriage meshes with the pinion, the rotational drive of a plurality of pinion shafts is controlled synchronously using a stepping motor or the like, and the rack engages with the pinion. There is a description of a traveling control method for a transport carriage in which the rotation speed of the pinion is reduced at the moment of insertion, the carriage is decelerated, and acceleration is performed after the rack and the pinion are completely engaged.
[0006]
[Problems to be solved by the invention]
However, in the conventional traveling control method of the carriage, the carriage is repeatedly decelerated and accelerated each time the rack is engaged with the pinion. Therefore, the carriage is frequently vibrated and the glass substrate is likely to be damaged such as chipping. In addition, since the number of times of deceleration on the conveyance path is large, the conveyance tact time is prolonged and the throughput of processing is reduced.
[0007]
The present invention has been made to solve the above-described problems, and transports a substrate quickly and smoothly without reducing the speed of the carriage in the vacuum processing chamber and without giving a fatal vibration or impact to the substrate. It is an object of the present invention to provide a high-throughput transport control method for a transport carriage that can be performed.
[0008]
[Means for Solving the Problems]
According to the present invention, there is provided a method for controlling the traveling of a transport carriage in a vacuum chamber, wherein a plurality of pinions arranged at predetermined intervals along a rail are engaged with a rack of the transport carriage to transmit driving force to the transport carriage. In the vacuum chamber traveling control method for transporting a held substrate to a plurality of vacuum processing chambers, (a) in the state where the preceding pinion is engaged with the rack and the driving force is transmitted to the transport cart, At the timing just before the pinion meshes with the rack, the subsequent servo motor is started with low torque,
(B) The drive of the preceding servo motor is switched from high torque to low torque at the moment when the subsequent pinion meshes with the rack, and at the same time, the drive of the subsequent servo motor is switched from low torque to high torque. It is characterized by that.
[0009]
In this case, the encoder detects the rotational speed while the preceding servo motor is driving the leading pinion with high torque, and based on this detected rotational speed, the low torque start timing of the succeeding servo motor in step (a) is detected. decide. In this way, there is no waste of idling the subsequent pinion when the cart is far away, and when the cart approaches, the subsequent servo motor can be started with low torque just before the subsequent pinion bites into the rack. , Power consumption is reduced.
[0010]
Moreover, it is preferable to synchronize the rotation of the preceding servo motor and the succeeding servo motor at the meshing timing of the succeeding pinion in the step (b). At this timing, the drive of the subsequent pinion is switched from the low torque to the high torque, the impact at the moment when the subsequent pinion meshes with the rack is reduced, and the vibration transmitted to the carriage is reduced. In particular, when a large substrate is transported, it is preferable to drive at high torque and low speed because the carriage receives an impact when the pinion / rack is engaged and vibration is transmitted to the substrate. Incidentally, the traveling speed of the carriage is switched in the range of 1.0 to 500 mm / second, and is accelerated or decelerated.
[0011]
In the control method of the present invention, the carriage is driven without reducing the speed by torque-controlling the carriage drive servomotor, and the impact transmitted to the carriage at the moment when the plurality of pinions mesh with the rack is reduced.
[0012]
That is, as shown in FIGS. 6A and 6B, at the timing t3 immediately before the second pinion meshes with the rack, the second motor is started with the low torque LT, and the moment when the second pinion meshes with the rack. At the timing t4, the driving torque of the first motor is switched from the high torque HT to the low torque LT, and at the same time, the driving torque of the second motor is switched from the low torque LT to the high torque HT. In this way, the propulsive force of the cart is smoothly switched from the first pinion to the second pinion, the cart is advanced by the high torque driving force transmitted from the second pinion, and the first pinion prevents the cart from moving forward. Continues rotating at a low torque LT that is not so weak.
[0013]
In the present invention, since the driving torque of the pinion is controlled without reducing the speed of the carriage, the role of transmitting the main driving force to the rack can be switched from the preceding pinion to the succeeding pinion. The impact and vibration transmitted to the carriage at the moment of meshing are greatly reduced.
[0014]
Further, in the present invention, the pinion driving servomotor is less likely to cause step-out, so that pinion synchronization adjustment is facilitated.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, various preferred embodiments of the present invention will be described with reference to the accompanying drawings.
[0016]
As shown in FIG. 1, in the cluster type vacuum processing system 1, a cart rotation chamber 16 as a common transfer chamber is disposed in the center, and a plurality of vacuum processing chambers 10, 18, and 20 are radially disposed around it. The cart rotation chambers 16 are connected to each other by a communication passage chamber (intermediate chamber) 19.
[0017]
Among the vacuum processing chambers, the load chamber 10 and the unload chamber 20 are provided with a gate valve mechanism 12 for blocking an opening between the front surface side and the external transfer path of the atmospheric atmosphere, and a common transfer chamber 16 with a vacuum atmosphere on the rear side. A gate valve mechanism 12 for blocking the opening therebetween is provided.
[0018]
Among the vacuum processing chambers, the plurality of film forming chambers 18 are each provided with a gate valve mechanism 12 that blocks an opening with the common transfer chamber 16. Openable and closable doors are attached to the back side of each film forming chamber 18 so that the inside of each film forming chamber 18 can be maintained by opening the door. The door is attached to each chamber so that the door can be manually opened and closed, and a seal member is interposed between the frame wall and the door constituting each chamber. A part of the plurality of film forming chambers 18 may be used as a spare chamber. Needless to say, the preliminary chamber is used as a film forming chamber, but may be used as a standby chamber in which the transport carriage 6 is temporarily standby (retracted), or the substrate G before the film forming process is reserved. Alternatively, it may be used as a preheating chamber for heating or a cooling chamber for cooling.
[0019]
The floor of the common transfer chamber 16 is composed of a turntable 17, and the turntable 17 rotates the transfer carriage 6 on the rail 8 in a horizontal plane so that the direction of the transfer carriage 6 can be changed to any direction of 360 °. It has become.
[0020]
As shown in FIG. 2, a pair of parallel rails 8 are laid so as to be connectable to the rotating rails 8 in the cart rotating chamber 16 from the external transport path through the load chamber 10, and the transporting cart 6 has one on each rail 8. It is designed to run one by one. Rails 8 in the load chamber 10 are respectively provided on the extended lines of the rails 8 of the external conveyance path, and the conveyance carriage 6 can be transferred from the external rails 8 to the internal rails 8 through the gate valve mechanism 12.
[0021]
Each transport cart 6 independently holds and transports one substrate G at a time. That is, the cart 6 includes a pair of support columns 62 and a plurality of support claws (not shown) on the main body frame 61, thereby holding one glass substrate G in a slightly inclined upright posture. Incidentally, the size of the glass substrate G is, for example, 1 m square. The 1 m square size glass substrate G has a weight of more than 10 kgf, which is a considerable weight.
[0022]
The transfer carriage 6 holding the substrate G enters the carriage rotation chamber 16 from the external transfer path through the load chamber 10, is rotated by the turntable 17, is aligned with the film formation chamber 18, and enters the film formation chamber 18. Then, after the film is formed on the substrate G, it passes through the cart rotation chamber 16 and the unload chamber 20 and goes out to the external conveyance path.
[0023]
As shown in FIG. 3, a plurality of pinions 72 are provided in the vicinity of the side of the rail 8 at a predetermined interval. These pinions 72 are arranged at positions where they can mesh with racks 64 formed on the side surfaces of the transport carriage 6. The mutual interval between the pinions 72 is shorter than the length (1.5 to 1.6 m) of the rack 64 of the carriage. For example, in the case of the carriage 6 that transports a 1 m square substrate G, the distance between the pinions 72 is 1.2 to 1.4 m. Is desirable. A stopper block 77 is attached to the terminal position of the rail 8 in the film forming chamber 18 so that the transport carriage 6 is stopped at a predetermined position.
[0024]
As shown in FIG. 4, servomotors 70A, 70B, and 70C are attached to each pinion 72, and the pinions 72 are driven to rotate independently. An encoder 75 is attached to each of the servo motors 70A, 70B, and 70C, and the detected motor rotation number signal is sent to the controller 80, respectively.
[0025]
When the rotational speed detection signal is input, the controller 80 obtains the current position of the transport carriage 6 and the scheduled point passage time based on the calculated result, and outputs a control signal to each of the servo motors 70A, 70B, and 70C according to the result. The drive torque and the rotation speed of each pinion 72 are controlled. The pinion drive motors 70A, 70B, and 70C provided on the same line of the rails 8 arranged in series are synchronously driven and controlled by the controller 80.
[0026]
As shown in FIG. 5, the transport carriage 6 includes a main body frame 61, a pair of support columns 62, and a plurality of roller wheels 63. A rack 64 is formed on one side surface of the main body frame 61, and the above-described pinion 72 is engaged therewith. The pair of support columns 62 are provided upright on the main body frame 61 so as to be inclined by about 10 ° with respect to the longitudinal orthogonal axis of the main body frame 61. The mutual interval between the columns 62 is slightly smaller than the long side of the substrate G, and is held and transported by the substrate G holding claws attached to the pair of columns 62. The support column 62 is firmly fastened to the main body frame 61 so as to withstand the weight of the substrate G. The support 62 and the main body frame 61 are made of a high-strength and strong metal material such as stainless steel. The plurality of roller wheels 63 are rotatably contacted with each part of the rail 8 having a T-shaped cross section, and are supported by a buffer mechanism for absorbing vibration and impact transmitted to the main body frame 61 of the carriage.
[0027]
Next, the case where the glass substrate G is transferred by the transfer carriage 6 in the cluster type vacuum processing system 1 will be described with reference to FIGS. 6 and 7.
[0028]
The transfer carriage 6 receives the substrate G from a roller frame mechanism (not shown) on the external transfer path, enters the cart rotation chamber 16 through the load chamber 10 from the external transfer path, and stops at the center of the turntable 17. The film is rotated by the turntable 17 and aligned with the film forming chamber 18, and preparations for entering the film forming chamber 18 are completed.
[0029]
When the preparation in the bogie rotation chamber is completed, the controller 80 sends a signal to the power source of the gate valve mechanism 12, drives the cylinder to open the gate valve, and sends a signal to the power source of the first motor 70A. As shown in (a), the first pinion 72 is activated with a low torque LT, switched to high torque HT drive after a predetermined time has elapsed, and the transport cart 6 is directed from the cart rotation chamber 16 toward the film formation chamber 18. Move forward.
[0030]
That is, as shown in FIG. 6A, the controller 80 starts the first motor 70A with the low torque LT at the timing t1, and at the timing t2, the controller 80 moves the first motor 70A from the low torque LT to the high torque. Switch to HT drive. At this time, the second motor 70B also rotates in synchronization with the first motor 70A in a low torque state. Incidentally, the second and third motors 70B and 70C start rotating at a low torque LT in synchronism with timing t1 when the first motor 70A starts rotating.
[0031]
As shown in FIG. 7B, the first motor 70A is driven with the high torque HT until the subsequent second pinion 72 is engaged with the rack 64 (time t2 to t4). As shown in c), the driving is switched from the high torque HT to the low torque LT when the subsequent pinion biting timing t4 comes.
[0032]
On the other hand, as shown in FIG. 6B, the controller 80 starts the second motor 70B with the low torque LT at a timing t1 before the timing t4 at which the second pinion 72 bites into the rack 64. As shown in FIG. 7D, the second motor 70B is switched from the low torque LT to the high torque HT drive at the timing t4. The second motor 70B is driven with a high torque HT until the subsequent third pinion 72 is engaged with the rack 64 (time t4 to t6), and the high torque is reached when the subsequent pinion engagement timing t6 is reached. The driving is switched from HT to low torque LT.
[0033]
As a result, the propulsive force of the conveyance carriage 6 is smoothly switched from the first motor 70A to the second motor 70B, the conveyance carriage 6 is advanced by the high torque driving force transmitted from the second motor 70B, and the first motor 70A is The rotation is continued with a low torque LT that is weak enough not to prevent the carriage 6 from moving forward.
[0034]
Further, as shown in FIG. 6C, the controller 80 activates the third motor 70C with the low torque LT at timing t5 slightly before timing t6 when the third pinion 72 engages with the rack 64. When the timing t6 is reached, the third motor 70C is switched from the low torque LT to the high torque HT drive.
[0035]
The third motor 70C is switched from the high torque HT to the low torque LT drive just before the tip of the transport carriage 6 collides with the stopper 77 (not shown), and the motor rotation speed is reduced. When the tip of the transport carriage 6 contacts the stopper 77, the transport carriage 6 stops. After the transfer cart 6 stops, the substrate G is transferred to the film forming mechanism in the film forming chamber, and then the transfer cart 6 is discharged out of the film forming chamber, the gate valve is closed, and the substrate G is formed in the film forming chamber 18 by plasma CVD. Film.
[0036]
After film formation, the controller 80 activates the third motor 70C to rotate reversely with low torque, then switches from low torque LT to high torque HT drive, and causes the transport carriage 6 to leave the film formation chamber 18. Further, the second motor 70B is reversely activated with a low torque, and then the drive is switched from the low torque LT to the high torque HT to smoothly shift the rack 64 from the third pinion 72 to the second pinion 72. Further, the first motor 70A is reversely activated with a low torque, and then the drive is switched from the low torque LT to the high torque HT, so that the rack 64 smoothly shifts from the second pinion 72 to the first pinion 72. . In this way, the transport cart 6 moves from the film forming chamber 18 to the cart rotation chamber 16, closes the gate valve, rotates the turntable 17, opens the gate valve, and transfers the cart from the cart rotation chamber 16 to the unload chamber 20. The carriage 6 moves forward and goes out through the unload chamber 20 to the external conveyance path.
[0037]
According to the above embodiment, since the subsequent motor is started with the low torque LT at a timing slightly before the timing when the subsequent pinion bites into the rack, the propulsive force of the carriage is smoothly switched from the preceding motor to the subsequent motor, The carriage is advanced by the high torque driving force transmitted from the succeeding motor, and the preceding motor continues to rotate at a low torque LT that is weak enough not to prevent the carriage from moving forward. For this reason, the impact transmitted to the carriage when the subsequent pinion is engaged is greatly relieved, and the vibration transmitted to the substrate is remarkably reduced.
[0038]
Moreover, although the said embodiment demonstrated the case where a 1m square size board | substrate was supported and conveyed, this invention is not restricted only to this, For example, a larger board | substrate, for example, a 1.2m square-1.5m square size large size It is also possible to hold and transport the substrate.
[0039]
【The invention's effect】
As described above in detail, according to the present invention, the driving torque of the pinion is controlled without reducing the speed of the transport carriage, so that the role of transmitting the main driving force to the rack is quickly and smoothly transferred from the preceding pinion to the succeeding pinion. The impact and vibration transmitted to the carriage at the moment when the subsequent pinion is engaged with the rack of the carriage can be greatly reduced. For this reason, the glass substrate of a conveyance target object is not substantially damaged, and the yield of a product improves significantly.
[0040]
In addition, according to the present invention, the pinion drive servomotor is less likely to step out, so that the synchronization adjustment of the pinion drive can be facilitated.
[Brief description of the drawings]
FIG. 1 is an internal perspective plan view showing a vacuum processing system provided with a transport carriage.
FIG. 2 is a perspective view showing a gate valve and a carriage transport path provided in a vacuum processing system.
FIG. 3 is an internal perspective plan view showing a carriage and a drive mechanism in a vacuum processing chamber.
FIG. 4 is an internal perspective side sectional view showing a carriage and a drive mechanism in a vacuum processing chamber.
FIG. 5 is a partially enlarged sectional view showing a drive mechanism and rails of the carriage.
FIGS. 6A to 6C are timing charts showing driving torques of the first, second and third motors, respectively, for explaining the method of the present invention.
FIGS. 7A to 7D are schematic views showing motors whose driving torque is controlled when the pinion / rack is engaged, in order to explain the method of the present invention.
[Explanation of symbols]
6 ... transport cart,
61 ... body frame,
62 ... posts,
63 ... Roller wheels,
64 ... rack,
70A, 70B, 70C ... Servo motor,
72 ... pinion,
75: Encoder,
8 ... Rail (carriage carriage path),
10 ... Road room,
16 ... Common transfer room (cart rotation room),
17 ... Turntable,
18 ... Film forming chamber (vacuum processing chamber, spare chamber),
19 ... Communication passage room (intermediate room),
20 ... unloading room,
77 ... The stopper block,
80 ... Controller,
G: Glass substrate.

Claims (3)

Along the rail to transmit the driving force of the plurality of pinions are respectively attached to a plurality of servo motors by bitten rack conveyance carriage a plurality of pinions which are arranged at a predetermined interval, the transport carriage In the vacuum chamber traveling control method of the transport carriage for transporting the held substrate to a plurality of vacuum processing chambers,
(A) in a state preceding the pinion driving force meshes with the rack is transferred to the transport carriage, and then start up the rear connection servomotor at low torque until a subsequent pinion meshes with the rack,
(B) the same time when the subsequent pinion switches the driving of the preceding servomotor said preceding pinion is mounted at the timing of the instant meshed with said rack from a high torque low torque, the driving of the rear connection servomotor low A method for controlling the traveling of a transport carriage in a vacuum chamber, wherein the torque is switched from torque to high torque. The rotational speed between said the rotational speed between said destination Gyosa Bomota is driven pinion of the lead in high torque subsequent servo motor is driven the subsequent pinion at low torque detected by the encoder, 2. The method for controlling the traveling of a transport carriage in a vacuum chamber according to claim 1 , wherein the controller controls the driving torque and the rotational speed of the preceding pinion and the subsequent pinion based on the detected rotational speed. In meshing timing of the subsequent pinion of the step (b), the leading servo motor and the subsequent servo transfer carriage according to one of claims 1 or 2 the rotation of the motor, characterized in that to synchronize Vacuum chamber travel control method.

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