JP3970042B2 - Method for controlling the traveling of a transport carriage in a vacuum chamber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling a travel of a conveying cart in a vacuum chamber, capable of transferring a substrate safely and reliably under a special environment where visual checking cannot can be performed. <P>SOLUTION: An abutment block is disposed at a location where a cart cannot advance ahead of a target stop position where a substrate is transferred from the cart to the other member in a vacuum processing chamber (a); a distance enough to lower a propulsive force of the cart before the cart abuts on the abutment block is set (b); the revolution of a pinion or a revolution of a pinion drive source is detected to calculate a location of the conveying cart based on the detected revolution (c); when a distance between a calculated position and the target stop position is equal to or smaller than the distance set by the step (b), the drive torque of the pinion is decreased to lower the propulsive force of the cart (d); and the cart is set to abut on the abutment block by the smaller propulsive force than when normally conveying, and the pinion is continually driven at low torque only in a predetermined period to continue to advance the cart in a state of abutting on the abutment block (e). <P>COPYRIGHT: (C)2003,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum chamber traveling control method for a transport carriage that transports a glass substrate in a vacuum processing chamber in which a CVD film is formed.
[0002]
[Prior art]
A conventional cart traveling control method will be described with reference to FIG. The vacuum processing system includes a vacuum processing chamber 101, a cart rotation chamber 102, and a vacuum processing chamber 103 connected in series via a gate valve 112. The transport carriage 6 is configured to run on the rail 8 by a driving force transmitted from the pinion 172 with the rack 64 formed on the side surface meshing with the pinion 172. The pinions 172 are arranged along the rail 8 at a predetermined interval, and are individually driven by stepping motors 170A to 170D controlled by the controller 180.
[0003]
The controller 180 controls the stepping motors 170A to 170D so that all the pinions 172 on the rails 8 arranged on the same line are rotated in a synchronized state. The transport cart 6 transports the glass substrate G from the vacuum processing chamber 101 to the cart rotation chamber 102 through the gate valve 112 that is opened and closed, and then from the cart rotation chamber 102 to the vacuum processing chamber 103 for film formation. The substrate G is delivered to a film forming unit (not shown) in the vacuum processing chamber.
[0004]
[Problems to be solved by the invention]
However, since the vacuum processing chamber for performing processing such as plasma CVD, sputtering, and dry etching on the substrate is surrounded by the outer wall of the chamber, the operator cannot stop the conveyance carriage at the target position while visually checking the chamber. In the environment. For this reason, the conventional cart traveling control method has the following problems (1) to (3).
[0005]
(1) Even if the positioning is electrically completed in the control system between the controller / stepping motor / pinion, it is possible to respond appropriately when mechanical backlash occurs at the carriage stop position at the board delivery location. Since this is not possible, the delivery operation of the substrate becomes uncertain, and the substrate may be damaged due to collision or dropping with other members.
[0006]
(2) In order to guarantee the transfer reproducibility in which the same result can be obtained when the same operation is repeated, high positional accuracy is set such that the stop position of the carriage is within ± 1 mm with respect to the target stop position (transfer position). Required.
[0007]
(3) It is necessary to confirm the target stop position of the transport carriage every time the apparatus is maintained, and the time required for maintenance increases accordingly.
[0008]
The present invention has been made to solve the above-described problems, and provides a vacuum carriage traveling control method for a transport carriage capable of safely and reliably delivering a substrate in a special environment where visual confirmation is impossible. Objective.
[0009]
[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 a vacuum chamber traveling control method of a transport carriage for transporting a held substrate to a plurality of vacuum processing chambers,
(A) A stopper block is arranged at a place where the transport carriage cannot move forward from a target stop position where the substrate is transferred from the transport carriage to another member in the vacuum processing chamber,
(B) setting a distance with a margin to reduce the propulsive force of the transport carriage before the transport carriage hits the stopper block;
(C) detecting the rotational speed of the pinion or the rotational speed of the pinion drive source, and calculating the position of the transport carriage based on the detected rotational speed;
(D) When the distance from the calculated position to the target stop position is the same as or smaller than the distance set in the step (b), the driving torque of the pinion is decreased to promote the transport carriage Reduce power,
(E) The conveyance carriage is caused to abut against the stopper block with a propulsive force smaller than that during normal conveyance, and the pinion is continuously driven at a low torque for a predetermined time and conveyed in a state where it is abutted against the stopper block. It is characterized by continuing to move the cart forward.
[0010]
In this case, it is preferable that the set distance in the step (b) is 90 to 110 mm. Since the steady speed of the conveyance carriage is 200 to 500 mm / second, there will be a time margin of 0.2 to 0.5 seconds until the conveyance carriage hits the stopper block after traveling this set distance. During this time, the control operation for switching the drive of the pinion drive source (servo motor) from high torque to low torque is completed.
[0011]
Moreover, in the said process (e), it is preferable to set the virtual driving | running | working distance which a conveyance trolley will advance to 100-300 mm as a thing without a corresponding stop block applicable while the conveyance trolley is contacting the stop block. .
[0012]
Furthermore, in the step (d), it is preferable to reduce the rotation speed of the pinion drive source and decelerate the transport carriage. Since the transport cart is a heavy object having a total weight exceeding 10 kg when the substrates are loaded, the inertial force is large. For this reason, even when the propulsive force (drive torque) transmitted from the pinion to the carriage is reduced, a large impact is generated when the conveyance carriage collides with the stopper block, which is transmitted to the substrate as vibration. This is because it is necessary to reduce as much as possible.
[0013]
Further, the rotation angle of the servo motor drive shaft is feedback controlled by detecting the motor rotation speed with the attached encoder, the gear teeth of the pinions arranged on the same line are aligned, and the pinion and the rack are synchronously engaged. Since the motor is synchronously controlled in this way, the impact at the moment when the 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.
[0014]
The vacuum processing chamber may be a film forming chamber for forming a plasma CVD film on a substrate, may be a cart rotating chamber that changes the transport direction of the substrate by rotating the transport cart, or It may be a load chamber in which the transport carriage enters the vacuum side from the atmosphere side, or an unload chamber in which the transport carriage exits from the vacuum side to the atmosphere side.
[0015]
When the vacuum processing chamber is a film forming chamber, the predetermined time in the step (e) is set as a time until the delivery of the substrate from the transfer carriage to another member is completed, and the substrate in the step (e). After completing the delivery, the pinion is rotated in the reverse direction, and the transport carriage is withdrawn from the film forming chamber.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, various preferred embodiments of the present invention will be described with reference to the accompanying drawings.
[0017]
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.
[0018]
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. As shown in FIG. 2, the gate valve mechanism 12 includes a gate valve that opens and closes a pair of left and right loading / unloading ports 12a and 12b, and a cylinder that drives each gate valve.
[0019]
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 opened and closed manually or electrically, 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.
[0020]
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.
[0021]
As shown in FIG. 2, a pair of parallel rails 8 are laid so as to be connectable from the atmospheric conveyance path through the load chamber 10 to the rotation rail 8 in the carriage rotation chamber 16, and the conveyance carriage 6 has one on each rail 8. It is designed to run one by one. The rails 8 in the load chamber 10 are respectively provided on the extended lines of the rails 8 of the atmospheric conveyance path, and the conveyance carriage 6 passes through the steps of the gate valve mechanism 12 from the rails 8 of the atmospheric conveyance path to the rails 8 of the vacuum conveyance path. You can change.
[0022]
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.
[0023]
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.
[0024]
As shown in FIGS. 3 and 4, 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.
[0025]
As shown in FIG. 3, each pinion 72 is connected to the rotation drive shafts of servo motors 70A and 70B arranged below the conveyance path, and the pinions 72 are driven independently by the servo motors 70A and 70B. It has become. An encoder 75 is attached to each of the servo motors 70A and 70B, and a signal that detects the motor rotation speed is sent to the controller 80, respectively. In this embodiment, the encoder 75 for detecting the motor rotation speed is employed. However, the present invention is not limited to this, and the pinion rotation speed may be detected using another encoder. .
[0026]
The stopper block 77B is attached only to the maintenance door side of the film forming chamber and the cart rotating table in the cart rotating chamber, does not have a vertical mechanism by the cylinder, and is fixed to the container of the film forming chamber and the cart rotating table with bolts. ing.
[0027]
The film forming chamber 18 is provided with two sets of device elements necessary for plasma CVD film forming, and a film forming unit (not shown) and a heater unit are arranged facing each other so as to sandwich the substrate transport path from both sides.
[0028]
The heater unit includes a planar heater element and a heater cover that covers the heater element. The heater cover is for protecting the heat generating surface of the heater element, and is supported by a pressing mechanism. The pressing mechanism is a mechanism that moves the heater cover toward the film forming unit.
[0029]
The film forming unit includes a ladder electrode with a gas supply function, a film forming unit cover, a temperature control heater, a substrate pressing plate, and an exhaust passage. A high frequency power source and a gas supply source are connected to the ladder electrode. The high frequency power source applies a high frequency of a predetermined frequency to the electrode, and generates plasma between the electrode and the substrate G. For example, a process gas mainly containing silane is contained as a reactive gas in the gas supply source.
[0030]
A second stop block 77B is fixed on the base surface of the rail 8 with bolts and nuts at a target stop position in the film forming chamber 18. The bolt hole is formed as a long hole so that the mounting position of the second stopper block 77B can be finely adjusted. The transport carriage 6 enters the film forming chamber 18 from the carriage rotation chamber 16, hits the second stopper block 77 </ b> B, and is stopped at the target stop position (that is, the substrate delivery position).
[0031]
The controller 80 includes the length of the conveyance path in each part of the system, the distance to the stopper blocks 77A and 77B in the vacuum processing chamber, the processing recipe for the substrate G, predetermined drive torques T1 and T2 in the servo motors 70A and 70B, and Rotational speeds V1, V2, etc. are provided as initial data, and the drive of each servo motor 70A, 70B is controlled based on this initial data and a detection signal input from each encoder 75. Further, the controller 80 performs synchronous drive control of the pinion drive motors 70A and 70B provided along the rails 8 arranged in series on the same line. Furthermore, the controller 80 also controls the length of time when the transport carriage 6 continues to abut against the stopper block 77B.
[0032]
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 larger than the long side of the substrate G, and the substrate G is placed between 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.
[0033]
Next, a 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. 3 and 6.
[0034]
The transport carriage 6 receives the substrate G from a roller frame mechanism (not shown) on the atmospheric transport path, enters the load chamber 10 from the atmospheric transport path, and stops at a target stop position in the load chamber 10. As a stop method, a stop position is set in advance in the servo motor, and the stop is performed based on the set position data.
[0035]
When the controller 80 receives a carry-in YES signal from the cart rotation chamber 16, it sends a signal to each power source of the gate valve mechanism 12 and the pinion drive servomotor 70 to open the gate valve and rotate the pinion 72. As a result, the transport cart 6 enters the cart rotation chamber 16 from the load chamber 10.
[0036]
Further, the controller 80 sends a signal to the servo motor, switches the drive of the pinion 72 from the steady speed / steady torque to the low speed / low torque, abuts the transport carriage 6 against the stop block 77A, and the target stop position in the carriage rotation chamber. To stop. This target stop position is substantially at the center of the turntable 17. Next, the transport carriage 6 is rotated by the turntable 17, the transport direction is aligned with the film forming chamber 18, and preparations for entering the film forming chamber 18 are completed.
[0037]
When the preparation in the bogie rotation chamber is completed, the controller 80 sends a signal to each power source of the gate valve mechanism 12 and the servo motors 70A and 70B, opens the gate valve, and further rotates the pinion 72. As a result, the transport cart 6 enters the film forming chamber 18 from the cart rotating chamber 16, hits the fixed stopper block 77 </ b> B, and stops at the target stop position in the film forming chamber.
[0038]
Next, the case where the transport carriage 6 enters the film forming chamber 18 and further leaves the film forming chamber 18 will be described in detail with reference to FIG.
[0039]
As shown in FIG. 6A, the controller 80 starts the motor 70B with the steady torque T1 at the timing t1, switches the driving of the motor 70B to the low torque T2 at the timing t2 after a predetermined time has elapsed, 6 is run with low torque.
[0040]
Further, as shown in FIG. 6B, the controller 80 starts the motor 70B at the steady speed V1 at the timing t1, and switches the driving of the motor 70B to the low speed V2 at the timing t2 after a predetermined time has elapsed. The carriage 6 is run at a low speed.
[0041]
The transport carriage 6 hits the stopper block 77B at a timing t3 after a predetermined time has elapsed. The controller 80 continues to supply power to the motor 70B and drive the pinion 72 until a predetermined time (time t3 to t6) elapses thereafter. However, since the conveyance carriage 6 is prevented from further moving forward by the stopper block 77B, the pinion 72 cannot rotate while being held in the rack 64.
[0042]
Note that the timing t2 at which the driving torque of the motor 70B is switched is the distance from the current position of the carriage at the time of driving switching to the stopper block 77B when the transport carriage 6 is traveling at the motor rotation speed V2 (average speed). It is set to be 100 mm. That is, the controller 80 determines the distance from the stop position (position of the stopper block 77A) in the cart rotation chamber to the target stop position (position of the stopper block 77B) in the film forming chamber, and the motor rotation speed V1 (average speed) in the first half. The second half of the motor rotation speed V2 (average speed), the time from the timing t1 to t3, and the virtual distance of 100 mm until the arrival at the stopper block 77B are substituted into a predetermined formula to calculate the timing t2. At the timing t2, a signal for switching the driving of the motor 70B to low torque T2 / low speed V2 is sent.
[0043]
Further, as shown in FIG. 6C, the controller 80 sends a signal to the delivery mechanism on the film forming unit side and the delivery mechanism on the carriage side at timing t4 after the carriage 6 hits the stopper block 77B. send. The pressing mechanism moves the heater cover forward and close to the substrate G on the carriage 6, releases the restraint of the substrate G by the holding claws, and transfers the substrate G from the support arm 62 of the carriage onto the support protrusion of the heater cover. During the transfer time t4 to t5 of the substrate G, the carriage 6 continues to advance in a state of low speed and low torque. Therefore, the stop position of the carriage 6 in the film forming chamber 18 is accurately set to the position of the stopper block 77B. Become. For this reason, the board | substrate G is reliably delivered with sufficient reproducibility from the cart side to the film forming unit side.
[0044]
After the plasma CVD film is formed on the substrate G in the film forming chamber 18, the reverse operation is performed to transfer the substrate G from the film forming unit side to the carriage side. In this way, the delivery of the substrate G is completed at the timing t5.
[0045]
Further, the controller 80 sends a signal to the gate valve mechanism 12 and the motor 70B at timing t6 after completion of film formation / substrate delivery, opens the gate valve, and as shown in FIGS. 6 (a) and 6 (b). The motor 70B is reversely rotated at a steady torque −T1 / steady speed −V1, and the carriage 6 is retreated from the film forming chamber 18 to the carriage rotating chamber 16.
[0046]
In the above embodiment, the traveling control of the transport carriage in the film forming chamber has been described. However, the present invention can also be applied to a cart rotation chamber, a load chamber, an unload chamber, and an intermediate chamber other than the film forming chamber. it can.
[0047]
【The invention's effect】
As described above in detail, according to the present invention, even when mechanical backlash occurs at the carriage stop position at the board delivery location, it is possible to appropriately cope with the board delivery operation safely and reliably. Therefore, there is no possibility of damaging the substrate due to collision or dropping with other members.
[0048]
Further, according to the present invention, the same result can be obtained when the same operation is repeatedly performed even when a high position accuracy is required for the stop position of the carriage with respect to the target stop position (delivery position). Delivery reproducibility can be guaranteed.
[0049]
Furthermore, according to the present invention, it is not necessary to confirm the target stop position of the transport carriage every time the apparatus is maintained, and the cost and time required for maintenance are reduced accordingly.
[Brief description of the drawings]
FIG. 1 is a 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 a perspective side sectional view showing a carriage and a drive mechanism in a vacuum processing chamber.
FIG. 4 is a perspective plan 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.
FIG. 6A is a timing chart showing servo motor driving torque (cart driving force) control, FIG. 6B is a timing chart showing servo motor rotation speed (cart driving speed) control, and FIG. The timing chart which shows delivery.
FIG. 7 is a diagram showing an outline of an apparatus used for conventional cart traveling control.
[Explanation of symbols]
6 ... transport cart,
8 ... Rail,
10 ... Road room,
12 ... Gate valve mechanism,
16 ... bogie rotation room (common transfer room),
18 ... film formation room,
19 ... Intermediate room (communication room),
20 ... unloading room,
61 ... body frame,
62 ... posts,
64 ... rack,
70A, 70B ... Servo motor,
72 ... pinion,
75: Encoder,
77A, 77B ... stopper block,
78 ... Elevating cylinder mechanism,
80 ... Controller,
G: Substrate.

Claims (10)

Transporting a plurality of pinions arranged at predetermined intervals along the rails into a rack of a transport carriage to transmit driving force and transporting a substrate held on the transport carriage to a plurality of vacuum processing chambers In the traveling control method of the dolly in the vacuum chamber,
(A) A stopper block is arranged at a place where the transport carriage cannot move forward from a target stop position where the substrate is transferred from the transport carriage to another member in the vacuum processing chamber,
(B) setting a distance with a margin to reduce the propulsive force of the transport carriage before the transport carriage hits the stopper block;
(C) detecting the rotational speed of the pinion or the rotational speed of the pinion drive source, and calculating the position of the transport carriage based on the detected rotational speed;
(D) When the distance from the calculated position to the target stop position is equal to or smaller than the distance set in the step (b), the driving torque of the pinion is decreased and the conveyance cart is promoted. Reduce power,
(E) The conveyance carriage is made to abut against the stopper block with a propulsive force smaller than that during normal conveyance, and the pinion is continuously driven at a low torque for a predetermined time and conveyed in the state where it is abutted against the stopper block. A method for controlling the traveling of a transfer carriage in a vacuum chamber that delivers a substrate from the transfer carriage to another member while continuing to advance the carriage. 請 Motomeko 1 method according shall be the 90~110mm the set distance of the step (b). While abuts the stop block against the conveying carriage in said step (e), will transport vehicle as there is no stop block Te applicable is advanced virtual travel distance 請 Motomeko 1 wherein shall be the 100~300mm the the method of. In the previous SL step (d), the smaller the rotational speed of the pinion drive source, 請 Motomeko 1 The method according to Ru slow down the transport carriage. Predetermined time, time 請 Motomeko 1 method according you to transfer the substrate from the transport carriage to another member to complete the step (e). After completing the transfer of the substrate in the previous SL step (e), the pinion rotated in reverse, 請 Motomeko 5 The method according to Ru is exiting the transport carriage from the vacuum processing chamber. 請 Motomeko 1 The method according to Ru with AC servo motors as said pinion drive source. The vacuum processing chamber, 請 Motomeko 1 method according Ru film chamber der to plasma CVD film formation on the substrate. The vacuum processing chamber rotates the conveyance carriage Ru carriage rotating chamber der changing the conveying direction of the substrate 請 Motomeko 1 The method according. The vacuum processing chamber, the load chamber, or the platform car is Ru unload chamber der exiting the vacuum side to the atmosphere side 請 Motomeko 1 method according to the conveyance carriage enters from the atmosphere side to the vacuum side.

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