JP2021072309A - Transport device and vacuum processing device - Google Patents

Abstract

To provide a transport device capable of reducing restrictions imposed on targets to which the transport device is applied, and a vacuum processing device.SOLUTION: A transport device includes: a first stator 13B1 configuring a first linear motor together with a movable element 13A; a second stator configuring a second linear motor together with the movable element 13A and located in the direction of travel of a tray T compared to the first stator 13B1; a first encoder detecting the drive amount by the first stator; a second encoder detecting the drive amount by the second stator; and a controller controlling the drive of each stator based on global coordinates of the tray T, the controller converting local coordinates output by each encoder to calculate the global coordinates.SELECTED DRAWING: Figure 3

Description

The present invention relates to a transport device for transporting trays configured so that a board can be placed in a non-contact manner, and a vacuum processing device.

A vacuum processing device that performs a film forming process on a substrate placed on a tray is used in the manufacture of flat panel displays, solar cells, and the like. The transport device included in the vacuum processing device transports the tray while magnetically levitating it in order to suppress the generation of dust or the like from the sliding member for transporting the tray (see, for example, Patent Document 1).

JP-A-2010-159167

The above-mentioned transfer device transfers a plurality of trays supplied to the transfer device to a plurality of vacuum chambers according to a processing order. At this time, as shown in FIG. 11, the encoder 102 for detecting the position of the tray 101 is mounted on the tray 101, which is a mover. Then, the drive device 103 for processing the output of the encoder 102 and the tray 101 are connected by a signal cable 104 or the like for transmitting the output of the encoder 102. As a result, a signal cable is provided as in the case where the vacuum chamber 100 is provided with a door 106 for carrying the tray 101, or the vacuum chamber 100 in the previous process and the vacuum chamber 100 in the subsequent process are connected by a gate valve 105. The above-mentioned transfer device cannot be applied to the vacuum processing device in which the 104 is difficult to move.

An object of the present invention is to provide a transfer device and a vacuum processing device capable of reducing the restrictions imposed on the object to which the transfer device is applied.

The transport device for solving the above problems is a transport device that transports a tray configured so that a substrate can be placed while magnetically levitating it. The tray is provided with a mover, and the mover and the first linear motor are provided. The first stator constituting the structure, the second stator constituting the mover and the second linear motor, and the second stator located in the traveling direction of the tray with respect to the first stator. A first encoder that detects the drive amount by the first stator, a second encoder that detects the drive amount by the second stator, and a control unit that controls the drive of each stator based on the global coordinates of the tray. And. Each encoder is an incremental encoder, and the control unit is configured to be able to convert the local coordinates output by each encoder to calculate the global coordinates, and for the preceding tray, the conversion target is the first encoder. After switching from the local coordinates of the above to the local coordinates of the second encoder and switching the conversion target, the first encoder increments the local coordinates of the following tray.

According to the transfer device, the global coordinates for controlling the drive of each motor are converted from the local coordinates of the first encoder and also converted from the local coordinates of the second encoder. This makes it possible to connect the signal cable for transmitting the output of the encoder to the device for transporting the tray instead of the tray. As a result, the transfer device can be applied to a vacuum processing device or the like in which it is difficult to move a signal cable between vacuum chambers adjacent to each other.

Further, after the conversion target is switched from the local coordinates of the first encoder to the local coordinates of the second encoder, the first encoder can increment the local coordinates for the next tray. This makes it possible to apply the above-mentioned transfer device even to a mass-produced machine that is required to continuously transfer a plurality of trays.

In the transfer device, when the control unit switches the target of action on the mover from the first stator to the second stator, the control unit changes the conversion target from the local coordinates of the first encoder to the second stator. Switch to the local coordinates of the encoder.

According to the transfer device, the conversion target is switched from the local coordinates of the first encoder to the local coordinates of the second encoder together with the switching of the action target on the mover. As a result, it is possible to match the switching of the conversion target and the switching of the action target, so that an error occurs in the global coordinates due to these inconsistencies, but it is also possible to suppress it. In addition, the conversion target can be switched more smoothly from the local coordinates of the first encoder to the local coordinates of the second encoder.

In the transfer device, the control unit uses the global coordinates when the target of action of the mover is switched from the first stator to the second stator as a compensation value, and the local coordinates output by the second encoder. In the conversion, the compensation value is added to the local coordinates output by the second encoder.

According to the above transport device, the local coordinates of the second encoder are converted by a simple calculation of adding the global coordinates at the time of switching the conversion target and the local coordinates output by the second encoder, and by extension, the global coordinates are converted. It will also be possible to obtain.

The transport device further includes a presence / absence detection unit that detects the presence of the tray, and the control unit sets the action target of the mover to the first when the presence / absence detection unit detects the presence of the tray. The 1 stator is switched to the 2nd stator, and the conversion target is switched from the local coordinates of the 1st encoder to the local coordinates of the 2nd encoder.

According to the above-mentioned transfer device, the conversion target is switched from the local coordinates of the first encoder to the local coordinates of the second encoder based on the detection of the presence / absence of the tray by the presence / absence detection unit. As a result, the conversion target can be more smoothly switched from the local coordinates of the first encoder to the local coordinates of the second encoder.

The vacuum processing device for solving the above problems includes a vacuum chamber, a tray on which a substrate can be placed, and a transport device for transporting the tray in the vacuum chamber, and the tray has a mover. The transport device is the above-mentioned transport device.

Top view of the internal structure of one embodiment of the vacuum processing apparatus as viewed from above. The side view which shows the side structure of the transport device. FIG. 2 is a sectional view taken along line III-III of FIG. FIG. 3 is a sectional view taken along line IV-IV of FIG. A block diagram functionally showing the configuration of a transport device. The block diagram which shows an example of offset data. The block diagram which shows an example of the current data. A control block diagram functionally showing the configuration of the control unit of the transport device. (A) to (d) The action diagram which shows the action of the transport process executed by a transport device. The operation diagram which shows the action of the braking process executed by a transfer device. The block diagram which shows the structure of the transfer apparatus in the vacuum processing apparatus of the conventional example.

Hereinafter, an embodiment of the transfer device and the vacuum processing device will be described.
[Vacuum processing equipment]
As shown in FIG. 1, the vacuum processing apparatus includes a plurality of vacuum chambers 1 and a plurality of gate valves 1 GV. The plurality of vacuum chambers 1 are arranged in one direction. The vacuum processing apparatus is, for example, an in-line type film forming apparatus.

Each vacuum chamber 1 is equipped with a vacuum pump 1TP. The vacuum pump 1TP depressurizes the inside of the vacuum chamber 1. Each vacuum chamber 1 shares a transfer device 2 with another vacuum chamber 1. The transfer device 2 carries in the tray T into each vacuum chamber 1 and carries out the tray T from each vacuum chamber 1. Each vacuum chamber 1 performs various treatments such as surface treatment, film formation treatment, and heat treatment on the substrate S placed on the tray T.

Each gate valve 1GV is connected to one vacuum chamber 1 and another vacuum chamber 1 adjacent to the vacuum chamber 1. Each gate valve 1GV switches between two adjacent vacuum chambers 1 between communicating and non-communicating. Each gate valve 1 GV allows the tray T to be transported between two vacuum chambers 1 adjacent to each other.

As shown in FIG. 2, the transport device 2 includes a transport unit 10 and a guide unit 20. The transport unit 10 is located at the bottom of the vacuum chamber 1. The guide portion 20 is located at the top of the vacuum chamber 1. Through these cooperation, the transport unit 10 and the guide unit 20 transport the tray T in the front-rear direction with the substrate S upright.

Hereinafter, the direction in which the tray T advances in the front-rear direction in which the tray T is conveyed is also referred to as the traveling direction X of the tray T. Further, the direction orthogonal to the traveling direction X and the vertical direction Z is also referred to as a left-right direction Y. The plurality of vacuum chambers 1 are arranged in the traveling direction X. The transport unit 10 and the guide unit 20 extend in the front-rear direction. The transport unit 10 and the guide unit 20 stand the substrate S substantially along the vertical direction Z.

[tray]
As shown in FIG. 2, the tray T includes a tray upper portion T1. The tray upper portion T1 has a square frame shape surrounding the substrate S. The tray upper part T1 fixes the substrate S to the tray upper part T1 by using a plurality of clamps or the like. The upper end of the tray upper portion T1 includes a guided member 21A. The guided member 21A is a permanent magnet extending in the traveling direction X. The guided member 21A faces a part of the guide portion 20 in the vertical direction Z.

As shown in FIG. 3, the tray T includes a tray lower portion T2. The tray lower portion T2 includes a pair of levitated magnets 11A on the left and right sides. Further, the tray lower portion T2 includes a pair of braked portions 12A on the left and right sides.

The tray lower portion T2 has an inverted U shape in which the lower end portion is branched in the left-right direction in a cross section including the left-right direction Y and the vertical direction Z. The tray lower part T2 has an inverted U-shaped cross section continuous in the front-rear direction. The tray lower portion T2 has a pair of movable vertical wall FTs on the left and right sides and a movable horizontal wall FB erected on the pair of movable vertical wall FTs. The lower tray T2 supports the upper tray T1 on which the substrate S is placed.

The movable horizontal wall FB is joined to the lower end of the tray upper portion T1. The two movable vertical wall FTs extend downward from both ends in the left-right direction of the movable horizontal wall FB. Each movable vertical wall FT is used to detect the tray position, which is the position of the tray T in the left-right direction Y. The position of the movable vertical wall FT on the right side in the left-right direction Y and the position of the movable vertical wall FT on the left side in the left-right direction Y are tray positions, respectively.

The levitation magnet 11A on the right side is located at the lower end of the movable vertical wall FT on the right side. The levitation magnet 11A on the left side is located at the lower end of the movable vertical wall FT on the left side. Each levitation magnet 11A is a permanent magnet. Each levitation magnet 11A extends in the traveling direction X over the entire traveling direction X in the tray lower portion T2.

The braked portion 12A on the right side is located on the right outer surface of the movable vertical wall FT on the right side. The braked portion 12A on the left side is located on the left outer surface of the movable vertical wall FT on the left side. Each braked portion 12A is a ferromagnet. Each braked portion 12A extends in the traveling direction X over the entire traveling direction X in the tray lower portion T2.

The lower tray T2 includes one scale 16A and one mover 13A. The mover 13A functions as a mover constituting the linear motor 13. The mover 13A includes a yoke 13A1 and a pair of magnets 13A2 to be conveyed on the left and right sides.

The yoke 13A1 has an inverted U shape in a cross section including the left-right direction Y and the vertical direction Z. The yoke 13A1 exists intermittently along the front-rear direction. Each yoke 13A1 has a pair of vertical yoke walls on the left and right, and a horizontal yoke wall erected on the pair of vertical walls. The yoke horizontal wall is joined to the lower surface of the movable horizontal wall FB.

The scale 16A is, for example, an incremental linear scale extending in the front-rear direction. The scale 16A is used for detecting the local coordinates, which is the position of the tray T in the local coordinate system. The local coordinate system is a one-dimensional coordinate system extending in the front-rear direction, and is a relative coordinate system for each detection unit that reads the scale 16A. The scale 16A has a plurality of patterns to be read over the entire tray T in the traveling direction X. The plurality of read patterns are arranged at equal intervals in the traveling direction X.

The magnet 13A2 to be conveyed on the right side is located on the inner right side surface of the vertical wall of the yoke on the right side. The magnet 13A2 to be conveyed on the left side is located on the inner left side surface of the vertical wall of the yoke on the left side. The plurality of magnets 13A2 to be conveyed are arranged in the front-rear direction over substantially the entire front-rear direction in the tray lower portion T2. The magnets 13A2 to be conveyed arranged in the front-rear direction are permanent magnets arranged by alternately reversing the magnetic poles along the front-rear direction.

[Transport device]
Returning to FIG. 2, the guide portion 20 has a columnar shape extending in the front-rear direction. The guide unit 20 includes a guide member 21B. The guide member 21B is a permanent magnet extending in the front-rear direction. The guide member 21B faces the guided member 21A in the vertical direction Z.

The guide member 21B and the guided member 21A face each other with different magnetic poles. The guide member 21B is a permanent magnet. The guide member 21B exerts a suction force on the guided member 21A so as to attract the tray T to the guide portion 20. The suction force exerted by the guide member 21B suppresses the upper portion of the tray T from being displaced in the left-right direction Y.

As shown in FIG. 3, the transport unit 10 includes a pair of braking rails 10A on the left and right sides. Each braking rail 10A extends in the front-rear direction over the entire front-rear direction of the transport portion 10.
The transport unit 10 includes a plurality of stators 10B. The plurality of stators 10B are arranged at intervals along the front-rear direction. As shown in FIG. 4, the distance between the stators 10B adjacent to each other in the front-rear direction is equal to or less than the length of the tray T in the front-rear direction. That is, the plurality of stators 10B are arranged in the front-rear direction so that one or more stators 10B face one mover 13A. Each stator 10B is sandwiched between two braking rails 10A in the left-right direction Y.

The gap in the left-right direction Y between the right braking rail 10A and each stator 10B is configured to accommodate the right movable vertical wall FT. The gap in the left-right direction Y between the left braking rail 10A and each stator 10B is also configured to accommodate the left movable vertical wall FT. Each stator 10B is configured to be sandwiched between the yoke vertical walls included in the yoke 13A1.

The transport unit 10 includes a pair of levitation magnets 11B on the left and right sides. The levitation magnet 11B on the right side is located in the gap between the braking rail 10A on the right side and the stator 10B. The levitation magnet 11B on the left side is located in the gap between the braking rail 10A on the left side and the stator 10B. Each levitation magnet 11B is a permanent magnet. Each levitation magnet 11B extends in the front-rear direction over the entire front-rear direction in the transport portion 10.

The levitation magnet 11B on the right side and the levitation magnet 11A on the right side have the same magnetic poles facing each other. The levitation magnet 11B on the left side and the levitation magnet 11A on the left side also face the same magnetic poles with each other. Each levitation magnet 11B faces a separate levitation magnet 11A in the vertical direction Z, and exerts a repulsive force on the levitation magnet 11A so as to keep the tray T away from the levitation magnet 11B. The repulsive force acted on by each levitation magnet 11B causes the tray T to levate by magnetic force.

Returning to FIG. 2, the transport unit 10 includes a plurality of braking magnets 12B. The plurality of braking magnets 12B are arranged at intervals along the front-rear direction. The distance between the braking magnets 12B adjacent to each other in the front-rear direction is equal to or less than the length of the tray T in the front-rear direction. That is, the plurality of braking magnets 12B are arranged in the front-rear direction so that one or more braking magnets 12B face the tray T.

As shown in FIG. 3, the plurality of braking magnets 12B are located on the left inner surface of the right braking rail 10A and the right inner surface of the left braking rail 10A. The braking magnet 12B on the right side is positioned so as to face the movable vertical wall FT on the right side provided in the lower part T2 of the tray, and to face the braked portion 12A on the right side when the tray T is in a raised state. The braking magnet 12B on the left side is positioned so as to face the movable vertical wall FT on the left side provided in the lower tray T2, and to face the braked portion 12A on the left side when the tray T is in a raised state.

Each braking magnet 12B is an electromagnet whose drive is controlled by the drive device 30. Each braking magnet 12B exerts an attractive force on the braked portion 12A so as to attract the tray T to the braking magnet 12B. When the value of the current flowing through each braking magnet 12B changes, the attractive force exerted by the braking magnet 12B changes. The attractive force exerted by each braking magnet 12B suppresses the lower portion of the tray T from being displaced in the left-right direction Y.

Each stator 10B includes a transport magnet 13B1. Each transport magnet 13B1 is positioned so as to face each yoke vertical wall included in the yoke 13A1 and to face each transport magnet 13A2 when the tray T is in a floating state. The distance between the transport magnets 13B1 adjacent to each other in the front-rear direction is equal to or less than the length of the tray T in the front-rear direction. That is, the plurality of transport magnets 13B1 are arranged in the front-rear direction so that one or more transport magnets 13B1 are sandwiched between the two transport magnets 13A2.

Each transport magnet 13B1 is an electromagnet whose drive is controlled by the drive device 30. The plurality of transport magnets 13B1 function as stators constituting the linear motor by changing the direction and magnitude of the current flowing through the transport magnets 13B1. The transport magnet 13B1 and the transport magnet 13A2 form separate linear motors.

The transport unit 10 includes a plurality of tray distance detection units 15. The plurality of tray distance detecting units 15 are located on the left inner surface of the right braking rail 10A and the right inner surface of the left braking rail 10A, like the braking magnet 12B. The plurality of tray distance detection units 15 are arranged at intervals along the front-rear direction. The tray distance detection unit 15 located on the right braking rail 10A faces the right outer surface of the right movable vertical wall FT. The tray distance detecting unit 15 located on the left braking rail 10A faces the left outer surface of the left movable vertical wall FT.

Each tray distance detecting unit 15 located on the right braking rail 10A is associated with, for example, one braking magnet 12B located on the right braking rail 10A. Each tray distance detecting unit 15 located on the left braking rail 10A is associated with, for example, one braking magnet 12B located on the left braking rail 10A.

Each tray distance detection unit 15 measures the distance in the left-right direction between the tray distance detection unit 15 and the movable vertical wall FT facing the tray distance detection unit 15. Each tray distance detecting unit 15 measures the distance between the movable vertical wall FT and the movable vertical wall FT in a non-contact manner. Each tray distance detection unit 15 is, for example, one of an optical distance sensor, an eddy current type distance sensor, an ultrasonic type distance sensor, and a capacitance type distance sensor. The tray position is grasped by detecting the tray distance, which is the distance between each tray distance detecting unit 15 and the movable vertical wall FT facing the tray distance detecting unit 15 in the left-right direction.

Each tray distance detection unit 15 outputs a measured value to the drive device 30. The drive device 30 controls the drive of each braking magnet 12B based on the distance between the braking magnet 12B and the movable vertical wall FT in the left-right direction.

The distance between the braking magnet 12B and the movable vertical wall FT in the left-right direction may be calculated based on the measured value of the tray distance detecting unit 15 associated with the braking magnet 12B. It may be imitated by the measured value of the tray distance detecting unit 15 associated with the braking magnet 12B. Alternatively, the distance between the braking magnet 12B and the movable vertical wall FT in the left-right direction is based on the measured values of the tray distance detecting unit 15 and the other tray distance detecting unit 15 associated with the braking magnet 12B. May be calculated. That is, the distance used for controlling the drive of the braking magnet 12B may be a measured value of the tray distance detecting unit 15 or an estimated value obtained from the measured values of the plurality of tray distance detecting units 15. Good.

The transport unit 10 includes a plurality of load sensors 13K. The load sensors 13K are arranged at intervals along the front-rear direction on the left inner side surface of the left braking rail 10A, for example. The load sensor 13K detects whether or not the tray T has reached the detection range of the load sensor 13K. Each load sensor 13K is, for example, a photo sensor that includes a detection range above the stator 10B on which the load sensor 13K is located and detects the presence or absence of the tray T in the detection range.
Each load sensor 13K outputs a detection result to the drive device 30. The drive device 30 controls the drive of each braking magnet 12B based on the detection result of each load sensor 13K. The drive device 30 starts driving the braking magnet 12B associated with each load sensor 13K based on the detection result of the load sensor 13K. The drive device 30 stops driving the braking magnet 12B associated with each load sensor 13K based on the detection result of the load sensor 13K.
As shown in FIG. 4, the transport unit 10 includes a plurality of presence / absence detection units 13B2. The presence / absence detection unit 13B2 is located at the lower end of each stator 10B. The transport magnet 13B1 is associated with each presence / absence detection unit 13B2 one by one.

Each presence / absence detection unit 13B2 detects whether or not the tray T has reached the detection range of the presence / absence detection unit 13B2. Each presence / absence detection unit 13B2 is, for example, a photo sensor that includes the upper part of the stator 10B where the presence / absence detection unit 13B2 is located as a detection range and detects the presence / absence of the tray T in the detection range.

Each presence / absence detection unit 13B2 outputs the detection result to the drive device 30. The drive device 30 controls the drive of each gate valve 1 GV based on the detection result of each presence / absence detection unit 13B2. The drive device 30 starts driving the transport magnet 13B1 associated with each presence / absence detection unit 13B2 based on the detection result of the presence / absence detection unit 13B2.

The transport unit 10 includes a plurality of reading units 16B. Each reading unit 16B is located at the upper end portion on the inner surface of the braking rail 10A. The distance between the reading units 16B adjacent to each other in the front-rear direction is equal to or less than the length of the tray T in the front-rear direction. The plurality of reading units 16B are arranged in the front-rear direction so that one or more reading units 16B face the scale 16A. The plurality of reading units 16B are arranged in the front-rear direction so that one or more reading units 16B face the scale 16A. One reading unit 16B is associated with each presence / absence detection unit 13B2, that is, one reading unit 16B is associated with each transport magnet 13B1.

When the scale 16A is located directly above the reading unit 16B, each reading unit 16B reads the pattern to be read from the scale 16A. Each reading unit 16B outputs a count-up signal to the drive device 30 each time one read pattern is read.

The scale 16A and each reading unit 16B detect the relative position of the tray T with respect to the reading unit 16B. The scale 16A and each reading unit 16B function as an incremental encoder that detects the position of the tray T in the local coordinate system. In other words, the transport device 2 and the tray T include a plurality of incremental encoders for detecting the position of the tray T in the local coordinate system, and the plurality of incremental encoders are arranged at intervals in the front-rear direction.

The drive device 30 measures the count-up signal output by each reading unit 16B as a count value for each reading unit 16B. The reading unit 16B starts reading the scale 16A when the transport magnet 13B1 associated with the reading unit 16B starts to be driven. The drive device 30 controls the drive of the transport magnet 13B1 associated with the reading unit 16B based on the count value of the reading unit 16B.

[Drive]
As shown in FIG. 5, the drive device 30 includes a control unit 31, a storage unit 32, and a drive unit 33. The control unit 31 is composed of, for example, hardware elements used in a computer such as a CPU, RAM, and ROM, and software. The control unit 31 is not limited to processing all kinds of processing by software.

For example, the control unit 31 may include an application specific integrated circuit (ASIC), which is dedicated hardware that executes at least a part of various processes. The control unit 31 may be configured as a circuit including one or more dedicated hardware circuits such as an ASIC, a microcomputer which is one or more processors operating according to software which is a computer program, or a combination thereof. Good.

The storage unit 32 stores various programs including the transfer program. The storage unit 32 stores various data including the current data 32A and the offset data 32B. The control unit 31 reads the transfer program stored in the storage unit 32 and the data, and executes the transfer program to cause the drive unit 33 to execute various processes such as the transfer process. The data stored in the storage unit 32 includes coordinate values in the global coordinate system of each presence / absence detection unit 13B2, each transport magnet 13B1, each reading unit 16B, and each braking magnet 12B.

[data]
As shown in FIG. 6, the offset data 32B is used to calculate the offset value Ki. The offset data 32B is a table in which the offset value Ki (i = m) is associated with the tray position Ym (m is an integer of 1 or more). The offset value Ki is a compensation value added to the suction force target value. The offset value Ki acts as a feedforward element, such as feedforward proportional gain for disturbances that depend on the tray position Ym. The offset value Ki may be a value determined based on a test or the like conducted in advance, or may be a value calculated using various parameters.

The suction force target value is calculated by feedback control in which the measured value of the tray position is used as the feedback value and the tray position is set to the target position. The suction force target value is calculated from, for example, the deviation between the speed for setting the tray position to the target position and the measured value of the speed in the left-right direction of the tray T. The offset value is a value for increasing the suction force command value from the suction force target value.

When the tray position is displaced in the above configuration, an external force that causes the tray position to deviate from the target position increases exponentially according to the displacement amount of the tray T. This is mainly because the levitation magnet 11A and the levitation magnet 11B are permanent magnets, which is a factor that destabilizes the transport of the tray T included in the above-described configuration.
For example, when the same poles of the magnets face each other to levitate the tray T, the side force that pushes the tray T in the left-right direction always acts on the tray T, and the farther the tray position is from the target position, the more this side Force increases. In the control that the suction force target value without the side force is added as the suction force, the tray position is measured and the suction force target value is calculated before the tray T is moved by the suction force that opposes the side force. It will be repeated many times, and it will take a lot of time to reach the target position of the tray.
The drive device 30 described above performs feedforward compensation for stably controlling the transport of the tray T by reducing such unstable factors. That is, the drive device 30 performs feedforward compensation using the offset value Ki that fluctuates depending on the tray position as the feedforward proportional gain. The drive device 30 uses the tray position as an observer for estimating the disturbance, and provides appropriate and responsiveness to the feedforward compensation of the disturbance depending on the displacement amount of the tray T, for example, the compensation of the disturbance by the side force. High compensation.

In the offset data 32B, for example, the tray position Y1 is associated with the offset value K1, the tray position Y2 is associated with the offset value K2, and the tray position Y3 is associated with the offset value K3. Further, in the offset data 32B, for example, the tray position Y4 is associated with the offset value K4, and the tray position Y5 is associated with the offset value K5.

In the offset data 32B, for example, the farther the tray position is from the braking magnet 12B, the larger the offset value is associated with the tray position. Further, the offset data 32B associates a constant value as an offset value when, for example, the distance between the tray position and the braking magnet 12B in the left-right direction Y is equal to or less than a predetermined value.

For example, when the distance between the tray position Ym and the braking magnet 12B is larger in the order of the tray positions Y3, Y4, Y5, the offset value Ki is larger in the order of the offset values K3, K4, K5. Further, when the distance between the tray positions Y1 and Y2 and the braking magnet 12B is equal to or less than a predetermined value and the distance between the tray positions Y3, Y4 and Y5 and the braking magnet 12B is larger than the predetermined value, the offset is offset. A constant value smaller than the value K3 is associated with the offset values K1 and K2.

As shown in FIG. 7, the current data 32A is used for calculating the current command value. The current command value is a command value of the current value to be passed through the braking magnet 12B, and is a current value for arranging the tray position at the target position. The target positions are, for example, the positions of the movable vertical wall FT on the right side in the left-right direction and the movable vertical wall FT on the left side in the left-right direction when the main surface of the substrate S is erected along the vertical direction Z. The position of.

The current data 32A is a table in which the current command value is associated with the tray position and the suction force command value. The attractive force command value is a command value of the attractive force acting on each braking magnet 12B. The suction force command value is a suction force for arranging the tray position at the target position. The suction force command value is calculated from the suction force target value and the offset value.

In the current data 32A, the tray position Ym and the suction force command value Fn (n is an integer of 1 or more) are associated with the current command value Thinm (n, m is an integer of 1 or more). In the current data 32A, the larger the attractive force command value Fn is, the larger the current command value Thin is associated with the attractive force command value Fn. Further, in the current data 32A, the larger the deviation between the tray position Ym and the target position, the larger the current command value Thin is associated with the tray position Ym.

For example, when the magnitude of the attractive force increases in the order of the attractive force command values F1, F2, F3, the magnitude of the current value Cinm is set so as to increase in the order of the current command values Ci11, Ci21, and Ci31. Further, when the deviation between the tray position and the target position increases in the order of the tray positions Y1, Y2, Y3, the magnitude of the current value is set so as to increase in the order of the current command values Ci11, Ci12, and Ci13.

[Control unit]
The control unit 31 inputs the detection results of the plurality of presence / absence detection units 13B2, and controls the drive of the transport magnet 13B1 associated with the presence / absence detection unit 13B2 based on the detection results of the presence / absence detection unit 13B2. The control unit 31 inputs the detection results of the plurality of load sensors 13K and controls the drive of the braking magnet 12B corresponding to the detection range of the load sensor 13K based on the detection results of the load sensor 13K. To do. The control unit 31 inputs the detection results of the plurality of presence / absence detection units 13B2, and controls the drive of the reading unit 16B associated with the presence / absence detection unit 13B2 based on the detection results of the presence / absence detection unit 13B2. The control unit 31 inputs count-up signals of the plurality of reading units 16B for each reading unit 16B, and controls the drive of the transport magnet 13B1 associated with the reading unit 16B based on the count value of the reading unit 16B. To do.

For example, when the presence / absence detection unit 13B2 detects the arrival of the tray T, the control unit 31 starts supplying a current to the transport magnet 13B1 associated with the presence / absence detection unit 13B2. Further, when the presence / absence detection unit 13B2 detects the arrival of the tray T, the drive device 30 stops the supply of current to the transport magnet 13B1 associated with other than the presence / absence detection unit 13B2. As a result, the drive device 30 drives the plurality of transport magnets 13B1 in the order of arrangement in the traveling direction X.

The control unit 31 counts, for example, the count-up signal output by the reading unit 16B, and calculates the position of the tray T in the global coordinate system, that is, the transport position. The count value of the reading unit 16B indicates the position of the tray T in the local coordinate system with the reading unit 16B as the reference position. The global coordinate system is a coordinate system in which reference positions of each local coordinate system are arranged in the front-rear direction in the order of arrangement of the reading units 16B. That is, the global coordinate system is a one-dimensional coordinate system along the front-rear direction, and for example, the position where the transportation is started is set as the reference position.

The control unit 31 converts the position of the tray T in the local coordinate system to the position of the tray T in the global coordinate system. The control unit 31 controls the direction and magnitude of the current flowing through each of the transport magnets 13B1 based on the position of the tray T in the global coordinate system. That is, the control unit 31 causes each transport magnet 13B1 and the transport magnet 13A2 to function as a linear motor based on the transport position of the tray T. The control unit 31 controls the direction and magnitude of the current flowing through each braking magnet 12B based on the position of the tray T in the global coordinate system.

As shown in FIG. 8, the control unit 31 includes an input unit 41, a position control unit 42, a speed control unit 43, a suction force determination unit 44, a current command value calculation unit 45, a speed counter 46, an offset value calculation unit 47, and addition / subtraction. A device 41A, 42A, and an adder 44A are provided.

The control unit 31 uses the measured value of the tray position on the left side and the target position of the tray position on the left side in calculating the current command value applied to the braking magnet 12B on the left side. The control unit 31 uses the measured value of the tray position on the right side and the target position of the tray position on the right side in calculating the current command value applied to the braking magnet 12B on the right side. That is, the control unit 31 causes the measured value of the tray position used for the calculation and the target position to be different from each other between the calculation of the current command value on the left side and the calculation of the current command value on the right side. In the following, the calculation of the current command value on the right side will be described in detail, and the description of the overlapping configuration will be omitted for the calculation of the current command value on the left side.

The input unit 41 inputs the target position of the tray position on the right side. The adder / subtractor 41A uses the measured value of the tray position on the right side as a feedback value, and calculates the deviation between the measured value of the tray position on the right side and the target position on the right side. The adder / subtractor 41A outputs the calculated deviation as a position deviation on the right side.

The position control unit 42 calculates the speed of the tray T for making the position deviation on the right side output by the adder / subtractor 41A zero. The position control unit 42 outputs the calculated tray T speed as a target value of the tray speed on the right side.

The speed counter 46 calculates the measured value of the current tray speed by using the measured value of the tray position on the right side as a feedback value and using the measured value of the current tray position and the measured value of the previous tray position. The adder / subtractor 42A outputs the deviation between the target value of the tray speed on the right side output by the position control unit 42 and the measured value of the tray speed this time as a speed deviation on the right side.

The speed control unit 43 calculates the suction force for making the speed deviation on the right side output by the adder / subtractor 42A zero. The speed control unit 43 outputs the calculated suction force as a suction force target value on the right side.

The suction force determination unit 44 determines whether or not the suction force target value is smaller than zero. When the suction force determination unit 44 determines that the suction force target value is zero or more, the suction force target value is output to the adder 44A. When the suction force determination unit 44 determines that the suction force target value is smaller than zero, the suction force determination unit 44 sets the suction force target value to zero and outputs the output to the adder 44A. That is, the suction force determination unit 44 determines whether the force corresponding to the suction force target value is the suction force or the repulsive force, and if it is determined to be the suction force, the suction force target value. Is output to the adder 44A, while when it is determined that the force is repulsive, the suction force target value is set to zero and the output is output to the adder 44A.

The offset value calculation unit 47 outputs an offset value based on the measured value of the tray position by using the measured value of the tray position and the offset data 32B. At this time, the offset value calculation unit 47 performs interpolation processing using the offset data 32B, thereby outputting an offset value Ki based on the measured value of the tray position. An example of the interpolation processing performed by the offset value calculation unit 47 is that linear interpolation such as linear interpolation, polynomial interpolation, or spline interpolation is performed between the tray positions Ym included in the offset data 32B, whereby the interpolation is not discrete. Outputs a continuous offset value. The adder 44A outputs the sum of the suction force target value on the right side and the offset value output by the offset value calculation unit 47 as the suction force command value Fn.

The current command value calculation unit 45 uses the suction force command value Fn output by the adder 44A, the measured value of the tray position, and the current data 32A, and the current command value based on the suction force command value Fn and the measured value. Is calculated. At this time, the current command value calculation unit 45 performs a two-dimensional interpolation process using the suction force command value Fn and the measured value of the tray position, thereby based on the suction force command value Fn and the measured value of the tray position. Calculate the current command value Thinm. An example of the two-dimensional interpolation processing performed by the current command value calculation unit 45 is linear interpolation such as linear interpolation, polynomial interpolation, or between the tray positions Ym included in the current data 32A and the attractive force command value Fn. , Spline interpolation is performed, thereby outputting a continuous non-discrete current command value. The current command value calculation unit 45 outputs the calculated current command value to the drive unit 33. The drive unit 33 detects the current value supplied to the braking magnet 12B on the right side, and feedback-controls the current value supplied to the braking magnet 12B on the right side so that the current value becomes the current command value.

[Action 1: Transport processing]
Next, an example of the transfer process executed by the drive device 30 will be described with reference to FIG. In the following, an example will be described in which the three reading units 16B continuously convey the two trays T on one path arranged in the traveling direction X. Note that FIG. 9 shows an example in which the distance between the presence / absence detection unit 13B2, the transport magnet 13B1 and the reading unit 16B that are adjacent to each other is slightly shorter than the length of the tray T in the front-rear direction.

9 (a) to 9 (d) show the position of the reading unit 16B and the position of each tray T in a one-dimensional global coordinate system extending in the traveling direction X. Further, the coordinate values of the tray T in each local coordinate system are shown on the upper side of the coordinate axes. In addition, the coordinate values of the transport position in the global coordinate system are shown below the coordinate axes. Hereinafter, the coordinate values in the local coordinate system are also referred to as local coordinates, and the coordinate values in the global coordinate system are also referred to as global coordinates.

As shown in FIG. 9, the global coordinates of the three reading units 16B are coordinate values YB1, YB2, and YB3 from upstream to downstream in the traveling direction X. The reading unit 16B located at the coordinate values YB1, YB2, YB3 is also referred to as a first reading unit 16B1, a second reading unit 16B2, and a third reading unit 16B3, respectively.

In the control unit 31, the presence / absence detection unit 13B2 associated with the coordinate values YB1, YB2, YB3 is also referred to as a first presence / absence detection unit, a second presence / absence detection unit, and a third presence / absence detection unit, respectively. The transport magnet 13B1 associated with each presence / absence detection unit 13B2 is also referred to as a first transport magnet, a second transport magnet, and a third transport magnet.

As shown in FIG. 9A, when the tip of the traveling direction X in the tray T reaches the coordinate value YB1, the first presence / absence detecting unit detects the arrival of the tray T. The drive device 30 starts supplying a current to the first transport magnet based on the detection result of the first presence / absence detection unit. Next, when the tip of the traveling direction X in the tray T begins to pass the coordinate value YB1, the control unit 31 counts up the count value of the first reading unit 16B1 in order from “0”. Under these series of controls, the magnet 13A2 to be transported and the magnet 13B1 to be transported are synchronized with each other when the tray T arrives, and the transport processing of the tray T is continued.

During this time, the drive device 30 uses the count value of the first reading unit 16B1 as the global coordinates of the tray T, and based on the count value of the first reading unit 16B1, the direction of the current supplied to the first conveying magnet and the direction of the current. , Change the size. As a result, the drive device 30 conveys the tray T in the traveling direction X. Further, the drive device 30 identifies the braking magnet 12B facing the tray T among the plurality of braking magnets 12B based on the detection result of the load sensor 13K, and supplies a current to the specified braking magnet 12B. To control.

That is, the control unit 31 sequentially calculates the transport position of the tray T, and drives the first transport magnet based on the calculated transport position so that the tray T reaches the predetermined position at a predetermined transport speed. Control. Further, the control unit 31 controls the drive of the braking magnet 12B based on the detection result of the load sensor 13K. The count value of the first reading unit 16B1 is an example of the local coordinates of the first encoder. Using the count value of the first reading unit 16B1 as the global coordinates of the tray T is an example of conversion of the first encoder to the local coordinates.

As shown in FIG. 9B, when the tip of the traveling direction X in the tray T reaches the coordinate value YB2, the second presence / absence detecting unit detects the arrival of the tray T. Then, based on the detection result of the second presence / absence detection unit, the drive device 30 starts supplying a current to the second transport magnet so as to maintain synchronization with the magnet 13A2 to be transported attached to the tray T, and at the same time, the first Stop supplying current to the transport magnet. Further, the control unit 31 counts up the count value of the second reading unit 16B2 in order from "0", and sets "1000", which is the global coordinate when the count value of the second reading unit 16B2 is "0". Use as compensation value. That is, the compensation value becomes the same value as the count value of the reading unit 16B1 when the count value of the second reading unit 16B2 is "0", and is passed. That is, a local coordinate switching event occurs.

During this period, the drive device 30 uses the value obtained by adding the compensation value “1000” to the count value of the second reading unit 16B2 as the global coordinates of the tray T. Then, the drive device 30 changes the direction and magnitude of the current supplied to the second transport magnet based on the global coordinates of the tray T. As a result, the drive device 30 further conveys the tray T in the traveling direction X. Further, the drive device 30 specifies the braking magnet 12B facing the tray T among the plurality of braking magnets 12B based on the global coordinates of the tray T, and controls the driving of the specified braking magnet 12B. Then, when the control unit 31 starts converting the count value of the second reading unit 16B2 into the global coordinates, the control unit 31 returns the count value of the first reading unit 16B1 to “0”.

That is, when the control unit 31 switches the target of action on the mover 13A from the first transport magnet to the second transport magnet, the control unit 31 sets the conversion source of the global coordinates from the local coordinates by the first read unit 16B1 to the second read. Switch to local coordinates by unit 16B2. At this time, the control unit 31 adds the compensation value to the local coordinates by the second reading unit 16B2 in the conversion of the local coordinates by the second reading unit 16B2. Then, when the control unit 31 switches the conversion target of the global coordinates to the local coordinates by the second reading unit 16B2, the first reading unit 16B1 can increment the local coordinates for the next tray T. The count value of the second reading unit 16B2 is an example of the local coordinates of the second encoder.

As shown in FIG. 9C, the drive device 30 converts the count value of the second reading unit 16B2 into the global coordinates of the tray T even while the tray T passes through the coordinate value YB2. In the conversion of the count value of the second reading unit 16B2, the compensation value "1000" is added to the count value of the second reading unit 16B2, and the added result is used as the global coordinates of the tray T. Then, the drive device 30 changes the direction and magnitude of the current supplied to the second transport magnet based on the conversion result of the count value of the second reading unit 16B2. As a result, the drive device 30 conveys the tray T in the traveling direction X. Further, the drive device 30 specifies the braking magnet 12B facing the tray T among the plurality of braking magnets 12B based on the conversion result of the count value of the second reading unit 16B2, and the specified braking magnet. Controls the drive of 12B.

For example, if the count value of the second reading unit 16B2 is "500", the compensation value "1000" is added to the count value "500" of the second reading unit 16B2, and the result is the addition. A certain "1500" is used as the global coordinates of the tray T. Then, the drive device 30 changes the direction and magnitude of the current supplied to the second transport magnet based on the global coordinates of the tray T being "1500". Further, the drive device 30 changes the magnitude of the current supplied to the braking magnet 12B based on the global coordinates of the tray T being "1500".

As shown in FIG. 9D, when the tip of the traveling direction X in the tray T reaches the coordinate value YB3, the third presence / absence detecting unit detects the arrival of the tray T. Then, based on the detection result of the third presence / absence detection unit, the drive device 30 starts supplying a current to the third transport magnet so as to maintain synchronization with the magnet 13A2 to be transported attached to the tray T, and at the same time, the second Stop supplying current to the transport magnet. Further, the control unit 31 counts up the count value of the third reading unit 16B3 in order from "0", and sets "2000", which is the global coordinate when the count value of the third reading unit 16B3 is "0". It is a compensation value. That is, the compensation value is the same as the value obtained by adding the immediately preceding compensation value to the count value of the reading unit 16B2 when the count value of the third reading unit 16B3 is "0", and is delivered. That is, a local coordinate switching event occurs.

During this period, the drive device 30 uses the value obtained by adding the compensation value “2000” to the count value of the third reading unit 16B3 as the global coordinates of the tray T. Then, the drive device 30 changes the direction and magnitude of the current supplied to the third transport magnet based on the global coordinates of the tray T. Further, the drive device 30 specifies the braking magnet 12B facing the tray T among the plurality of braking magnets 12B based on the global coordinates of the tray T, and controls the driving of the specified braking magnet 12B. As a result, the drive device 30 further conveys the tray T in the traveling direction X. When the control unit 31 starts converting the count value of the third reading unit 16B3 into the global coordinates, the control unit 31 returns the count value of the second reading unit 16B2 to “0”.

That is, when the control unit 31 switches the target of action on the mover 13A from the second transport magnet to the third transport magnet, the control unit 31 reads the global coordinate conversion source from the local coordinates by the second read unit 16B2. Switch to local coordinates by unit 16B3. At this time, the control unit 31 adds the compensation value to the local coordinates by the third reading unit 16B3 in the conversion of the local coordinates by the third reading unit 16B3. Then, when the control unit 31 switches the conversion target of the global coordinates to the local coordinates by the third reading unit 16B3, the second reading unit 16B2 can increment the local coordinates for the next tray T.

When the tip of the traveling direction X in the subsequent tray T reaches the coordinate value YB1, the first presence / absence detection unit detects the arrival of the tray T again. Based on the detection result of the first presence / absence detection unit, the drive device 30 starts supplying a current to the first transport magnet again so as to maintain synchronization with the magnet 13A2 to be transported attached to the tray T. Further, when the tip end portion of the traveling direction X in the subsequent tray T begins to pass the coordinate value YB1, the control unit 31 counts up the count value of the first reading unit 16B1 again in order from "0". Then, the control unit 31 repeats the control of the drive of each reading unit 16B, each conveying magnet 13B1, and each braking magnet 12B in the same manner as in the preceding tray T.

[Action 2: Braking process]
The control unit 31 inputs a measured value output by the tray distance detection unit 15 on the right side when controlling the drive of the braking magnet 12B on the right side, and is associated with the tray distance detection unit 15 for braking on the right side. The drive of the magnet 12B is controlled based on the measured value of the tray distance detecting unit 15. Similarly, when controlling the drive of the left braking magnet 12B, the control unit 31 inputs the measured value output by the left tray distance detection unit 15, and drives the left braking magnet 12B on the left side. Control is performed based on the measured value of the tray distance detection unit 15.

That is, the control unit 31 calculates the suction force target value on the right side from the position deviation of the tray position on the right side and the speed deviation of the tray T on the right side, using the measured value of the tray position on the right side as a feedback value. To do. Similarly, the control unit 31 uses the measured value of the tray position on the left side as a feedback value, and sets the suction force target value on the left side from the position deviation of the tray position on the left side and the speed deviation of the tray T on the left side. calculate.

Next, the control unit 31 uses the measured value by the tray distance detecting unit 15 on the right side and the offset data 32B to calculate the offset value Ki based on the measured value as an offset value applied to the braking magnet 12B on the right side. To do. Then, the control unit 31 calculates the sum of the suction force target value on the right side and the offset value on the right side as the suction force command value on the right side. Further, the control unit 31 uses the measured value by the tray distance detecting unit 15 on the left side and the offset data 32B to calculate the offset value Ki based on the measured value as an offset value applied to the braking magnet 12B on the left side. To do. Then, the control unit 31 calculates the sum of the suction force target value on the left side and the offset value on the left side as the suction force command value on the left side.

Next, the control unit 31 calculates the current command value applied to the braking magnet 12B on the right side and the current command value applied to the braking magnet 12B on the left side using the common current data 32A. That is, the control unit 31 uses the measured value by the tray distance detecting unit 15 on the right side, the suction force command value on the right side, and the current data 32A to measure the value measured by the tray distance detecting unit 15 on the right side and the suction force on the right side. Calculate the current command value based on the command value. Further, the control unit 31 uses the measured value by the tray distance detecting unit 15 on the left side, the suction force command value on the left side, and the current data 32A, and the measured value by the tray distance detecting unit 15 on the left side and the suction force on the left side. Calculate the current command value based on the command value.

In this way, the suction force command value Fn calculated by the drive device 30 is calculated by feedback control using the tray position Ym. The current command value Thin calculated by the drive device 30 is calculated using the calculated suction force command value Fn, the measured value of the tray position, and the current data 32A. As a result, as shown in FIG. 10, the current value supplied to the braking magnet 12B is the distance between the tray distance detecting unit 15 and the tray T, that is, the acting distance W between the braking magnet 12B and the tray T. Is the reflected value.

Further, the attractive force command value Fn for generating the current command value Thinm is an added value of the attractive force target value and the offset value Ki. The offset value Ki for calculating the suction force command value Fn is calculated by using the offset data 32B and the measured value of the tray position. As a result, the current value supplied to the braking magnet 12B becomes large enough to bring the tray position Ym closer to the target position by the amount of the offset value Ki.

As described above, according to the above embodiment, the following effects can be obtained.
(1) Since the global coordinates of the tray T are converted from the local coordinates of each reading unit 16B included in the transport unit 10, the signal cable for transmitting the output of the encoder is transported to the tray T instead of the tray T. It becomes possible to connect to the device for. Therefore, the transfer device 2 can be applied to a vacuum processing device or the like in which it is difficult to move the signal cable between the vacuum chambers 1 adjacent to each other.

(2) Further, after the conversion target is switched from the local coordinates of the first reading unit 16B1 to the local coordinates of the second reading unit 16B2, the first reading unit 16B1 receives the arrival of the next tray T and the local coordinates. Can be incremented. Therefore, the transfer device 2 can be applied to a mass-produced machine that is required to continuously transfer a plurality of trays T.

(3) Switching the conversion target from the local coordinates of the first reading unit 16B1 to the local coordinates of the second reading unit 16B2 switches from driving the first transport magnet to driving the second transport magnet. That is, it is performed together with the switching of the action target on the mover 13A. This makes it possible to match the switching of the conversion target with the switching of the action target. As a result, for example, the conversion target is not switched even though the reading by the first reading unit 16B1 is impossible, or the conversion target is switched even though the reading by the second reading unit 16B2 is impossible. It is suppressed that it occurs. That is, it is possible to suppress an error in the global coordinates due to the inconsistency between the switching of the conversion target and the switching of the action target.

(4) Further, the conversion target can be more smoothly switched from the local coordinates of the first reading unit 16B1 to the local coordinates of the second reading unit 16B2. This means that the tray T can be smoothly conveyed even when the door 106 or the gate valve 105 is present within the distance at which the local coordinates can be switched, that is, the distance between the reading units 16B. The distance between the reading units 16B may be slightly shorter than the length of the tray T in the front-rear direction, or only the scale 16A may be extended to provide a corresponding distance.
(5) It is also possible to convert the local coordinates of the second reading unit 16B2 by a simple calculation of adding the global coordinates at the time of switching the conversion target and the local coordinates output by the second reading unit 16B2.

(6) Switching the conversion target from the local coordinates of the first reading unit 16B1 to the local coordinates of the second reading unit 16B2 is performed based on the detection of the presence / absence of the tray T by the second presence / absence detection unit. As a result, the conversion target is switched based on the actual existence or non-existence of the tray T. Therefore, for example, the conversion target is not switched even though the first reading unit 16B1 cannot read the tray T, or the conversion target is not switched. 2 It is also possible to suppress switching of conversion targets even though reading by the reading unit 16B2 is impossible. That is, it is possible to suppress an error in the global coordinates due to the inconsistency between the switching of the conversion target and the switching of the reading unit.

(7) For braking between the case where the attractive force command value Fn is calculated at the tray position near the braking magnet 12B and the case where the attractive force command value Fn is calculated at the tray position far from the braking magnet 12B. The working distances of the attractive forces that the magnet 12B acts on the tray T are different from each other. Such a spatial difference for applying the suction force can be reduced by calculating the current command value Thinm associated with the tray position Ym. This makes it possible to suppress the occurrence of unstable behavior such as rocking in the left-right direction on the tray.

(8) Since the current command value Thinm associated with the measured value of the tray position and the suction force command value Fn is calculated from the table, it is possible to improve the feasibility of obtaining the effect according to the above (7). It will also be possible.

(9) Further, the actual attractive force exerted by the braking magnet 12B on the tray T becomes smaller as the distance between the tray T and the braking magnet 12B becomes longer, so that the effect according to (7) above can be obtained. It is also possible to further improve the feasibility of.

(10) The offset value Ki, which fluctuates depending on the tray position, is used as the feedforward proportional gain. Therefore, it is possible to compensate for disturbances such as side force that deviate from the target position in an appropriate and highly responsive manner.

(11) The longer the distance between the tray T and the braking magnet 12B, the larger the offset value Ki and the higher the attractive force, so that the effect according to (10) above can be obtained. It is possible to increase the effectiveness of the matter.

(12) Further, when the distance between the measured value of the tray position and the braking magnet 12B is equal to or less than a predetermined value, the offset value Ki can be set to a constant value, so that the actual suction acting on the tray T can be achieved. Excessive force can be suppressed.

The above embodiment can be modified and implemented as follows.
[Current data]
-The current data 32A can be changed to various arithmetic expressions. The calculation formula is a relational expression between the tray position Ym and the suction force command value Fn and the current command value Thinn, which makes it possible to calculate the current command value Thin from the tray position Ym and the suction force command value Fn. .. In short, the current data 32A may have a configuration in which the current command value for compensating for the spatial difference of the difference in the distance on which the braking force acts can be calculated from the tray position and the suction force command value.

-A part of the current data 32A may associate a current command value Thinm equal to each other for a plurality of combinations of the tray position Ym and the suction force command value Fn. For example, with respect to the range of the tray position Ym in which the tray position Ym is near the target position, a constant current command value Thin may be associated with the plurality of tray positions Ym.

[Offset data]
-The offset data 32B can be changed to various arithmetic expressions. The calculation formula is a relational expression between the tray position Ym and the offset value Ki, which makes it possible to calculate the offset value Ki from the tray position Ym. In short, the offset data 32B may have a configuration in which the offset value Ki for bringing the tray position Ym closer to the target position can be calculated from the measured value of the tray position.

All of the offset values Ki constituting the offset data 32B can be changed to larger values as the tray position Ym moves away from the braking magnet 12B.
The offset value Ki constituting the offset data 32B is not limited to a value that raises the suction force command value higher than the suction force target value. For example, when the position control unit 42 and the speed control unit 43 are configured so that a suction force target value larger than the actual suction force is always calculated, the suction force command value is set higher than the suction force target value. The offset data 32B is configured by a lowering offset value Ki.

Alternatively, the position control unit 42 and the speed control unit 43 always calculate the first range in which the suction force target value larger than the actual suction force is always calculated, and the suction force target value smaller than the actual suction force. The second range to be formed may be configured to be identifiable as a range of tray positions. In this case, the offset data 32B includes an offset value Ki such that the suction force command value is lower than the suction force target value in the first range, and the suction force command value is lower than the suction force target value in the second range. It is provided with an offset value Ki that enhances.

In short, the offset value Ki may be a compensation value added to the suction force target value, and may be a value that compensates for disturbances that deviate from the target position based on the tray position Ym.

The offset data 32B can be changed to a configuration in which a constant value is associated with the offset value Ki in a range in which the distance between the tray position Ym and the braking magnet 12B in the left-right direction Y is equal to or greater than a predetermined value.

[encoder]
-The scale 16A is not limited to the incremental linear scale, but can be changed to an incremental rotary scale. At this time, the stator 10B is, for example, a rotating body having a rotation axis in the left-right direction, and includes an outer peripheral surface in which magnetic poles different from each other are alternately repeated along the circumferential direction. Then, the stator 10B is configured to follow the rotation of the rotating body and advance the mover 13A in the traveling direction X. The scale 16A is attached to the stator 10B so that the pattern to be read rotates following the rotation of the stator 10B.

That is, the scale 16A may be provided on the stator 10B instead of the tray T. With this configuration, the scale 16A can be omitted from the tray T, and the configuration provided in the tray T can be simplified.

[Braking force]
-In the above embodiment, an example has been described in which the braking force for arranging the tray position at the target position is the attractive force for attracting the tray T toward the braking magnet 12B. Not limited to this, the braking force for arranging the tray position at the target position may be a repulsive force that keeps the tray T away from the braking magnet 12B. In this case, the braked portion 12A is a permanent magnet.

When the braked portion 12A is a permanent magnet, when the direction of the current flowing through the braking magnet 12B changes, the magnetic force acting on the braked portion 12A also changes from attractive force to repulsive force or from repulsive force to attractive force. Therefore, the set of the braked portion 12A and the braking magnet 12B may be configured to be located only on either the right side or the left side of the tray T in the left-right direction.

-In the above embodiment, an example in which the tray distance detecting unit 15 is associated with one braking magnet 12B one by one has been described. By changing this, the distance between the tray distance detection units 15 adjacent to each other and the distance between the braking magnets 12B adjacent to each other in the traveling direction X may be different from each other.

For example, two or more braking magnets 12B may be associated with one tray distance detecting unit 15. At this time, the drive device 30 has, for example, the coordinate values of each braking magnet 12B in the global coordinate system. Further, the drive device 30 specifies the braking magnet 12B in which the distance between the transport position of the tray T and the braking magnet 12B is equal to or less than a predetermined value. Then, the drive device 30 controls the drive of the specified braking magnet 12B so as to suppress the displacement of the tray T in the left-right direction.

For example, two or more tray distance detection units 15 may be associated with one braking magnet 12B. At this time, the drive device 30 has, for example, the coordinate values of each braking magnet 12B in the global coordinate system. Further, the drive device 30 specifies the braking magnet 12B in which the distance between the transport position of the tray T and the braking magnet 12B is equal to or less than a predetermined value. Then, the drive device 30 specifies the posture of the tray T from the measured values of each tray distance detection unit 15, and controls the drive of the specified braking magnet 12B so as to suppress the displacement of the tray T in the left-right direction. ..
The tray distance detection unit 15 may be configured to be located on only one of the left and right sides sandwiching the tray T. Since the distance between the braking magnets 12B in the left-right direction and the width of the tray T in the left-right direction can be grasped in advance, if the distance on one of the left and right sides sandwiching the tray T is detected, It is possible to calculate the distance on the other side.

[Other]
The guided member 21A may be a magnetic material that is attracted to the guide portion 20. In short, the guided member 21A may be configured to be displaced upward in the vertical direction Z by receiving a magnetic force applied by the guide portion 20.

The guide member 21B may be a magnetic material that attracts the tray T. In short, the guide member 21B may be configured to displace the guided member 21A upward in the vertical direction Z in response to the magnetic force acted by the guided member 21A.

The braked portion 12A may be a magnetic material that is attracted to the braking magnet 12B. In short, the braked portion 12A may be configured to displace the braked portion 12A in the left-right direction in response to the magnetic force applied by the braking magnet 12B.

The drive device 30 may have a configuration in which the presence / absence detection unit 13B2 is omitted. At this time, the drive device 30 has, for example, the global coordinates of each transport magnet 13B1. Then, the drive device 30 specifies the transport magnet 13B1 in which the distance between the transport position of the tray T and the transport magnet 13B1 is equal to or less than a predetermined value based on the transport position so that the tray T is transported in the traveling direction X. In addition, the drive of each of the specified transport magnets 13B1 may be controlled.
-The drive device 30 may have a configuration in which the load sensor 13K is omitted. At this time, the driving device 30 specifies the braking magnet 12B facing the tray T among the plurality of braking magnets 12B based on the count value of the first reading unit 16B1 and drives the specified braking magnet 12B. To control.

The control unit 31 omits the calculation of the current command value Thin using the current data 32A, that is, the calculation of the current command value Thin corresponding to the measured value of the tray position and the attractive force command value Fn, and simply simply. It is possible to change the configuration to calculate the current command value from the attraction command value Fn. Even with this configuration, it is possible to obtain the effects according to the above (1) to (6) and the above (10) to (12).

-The control unit 31 omits the calculation of the offset value Ki using the offset data 32B and the addition of the suction force target value and the offset value Ki, and changes the configuration so that the suction force target value is the suction force command value Fn. It is possible. Even with this configuration, it is possible to obtain the effects according to the above (1) to (8).

-The transport device may transport the tray with the substrate S tilted along the horizontal plane.

Ci11, Ci12, Ci13, Ci21, Ci31, Tinm ... Current command value, K1, K2, K3, K4, K5, Ki ... Offset value, S ... Board, T ... Tray, Y1, Y2, Y3, Y4, Y5, Ym ... Tray position, 1 ... Vacuum chamber, 2 ... Transfer device, 10 ... Transfer unit, 30 ... Drive device, 32A ... Current data, 32B ... Offset data.

Claims (5)

It is a transport device that transports a tray that is configured to allow a substrate to be placed while magnetically levitating.
The tray has a mover
The mover, the first stator constituting the first linear motor, and
The second stator constituting the mover and the second linear motor, which is located in the traveling direction of the tray with respect to the first stator, and the second stator.
A first encoder that detects the amount of drive by the first stator, and
A second encoder that detects the amount of drive by the second stator, and
A control unit that controls the drive of each stator based on the global coordinates of the tray is provided.
Each encoder is an incremental encoder,
The control unit is configured to be able to calculate the global coordinates by converting the local coordinates output by each encoder, and for the preceding tray, the conversion target is the second encoder from the local coordinates of the first encoder. After switching to the local coordinates of the above and switching the conversion target, the first encoder increments the local coordinates of the following tray. When the control unit switches the target of action on the mover from the first stator to the second stator, the control unit changes the conversion target from the local coordinates of the first encoder to the local coordinates of the second encoder. The transport device according to claim 1, which is switched. The control unit uses the global coordinates when the target of action of the mover is switched from the first stator to the second stator as a compensation value, and in the conversion of the local coordinates output by the second encoder, the first 2. The transport device according to claim 2, wherein the compensation value is added to the local coordinates output by the encoder. A presence / absence detection unit for detecting the existence of the tray is further provided.
When the presence / absence detection unit detects the presence of the tray, the control unit switches the action target of the mover from the first stator to the second stator, and changes the conversion target to the first. The transport device according to any one of claims 1 to 3, which switches from the local coordinates of the encoder to the local coordinates of the second encoder. With a vacuum chamber
A tray on which the board can be placed and
A transport device for transporting the tray in the vacuum chamber is provided.
The tray includes a mover and
The transfer device is a vacuum processing device according to any one of claims 1 to 4.

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