JP7306957B2 - Transfer device and vacuum processing device - Google Patents

Description

The present invention relates to a transfer device that transfers a tray on which a substrate can be placed in a non-contact manner, and a vacuum processing apparatus that includes the transfer device.

2. Description of the Related Art A vacuum processing apparatus that performs a film forming process on a substrate placed on a tray is used to manufacture flat panel displays, solar cells, and the like. A conveying device provided in a vacuum processing apparatus conveys a tray while magnetically levitating it in order to suppress generation of dust or the like from a sliding member for conveying the tray (see, for example, Patent Document 1).

JP 2016-103633 A

The transport device described above includes an electromagnet facing the right side of the tray and an electromagnet facing the left side of the tray. The two electromagnets act as an attractive force that attracts the tray to the electromagnets. The attraction force exerted on the tray by the two electromagnets suppresses the position of the magnetically levitated tray from being biased to the right and the position of the tray to be biased to the left.

On the other hand, the command value of the attractive force for driving the electromagnet is calculated by feedback control using the tray position as a feedback value. As a result, the command value of the suction force is calculated such that the tray position is arranged at the target position. However, even if mutually equal suction force command values are calculated, if the tray positions are different from each other, the actual suction forces acting on the trays will also be different from each other. For example, even if mutually equal command values of attraction force are calculated, if the tray position is close to the electromagnet, the attraction force that actually acts becomes large. Conversely, if the tray position is far from the electromagnet, the actual attractive force will be small. Then, the difference between the calculated suction force command value and the actual suction force acting on the tray causes the tray to exhibit unstable behavior such as rocking in the horizontal direction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a transfer apparatus and a vacuum processing apparatus that can suppress changes in tray position.

A transport apparatus for solving the above problems includes a transport unit that transports a tray on which a substrate can be placed in the front-back direction while magnetically levitating it, a measurement unit that measures the tray position that is the position of the tray in the left-right direction, a suppressing unit that suppresses a change in the tray position by a braking force of an electromagnet; a braking force command value for arranging the tray position at a target position; and converting the braking force command value into a current command value for the electromagnet. and a driving device for The driving device has current data for obtaining the current command value for arranging the tray position at the target position from the tray position and the braking force command value, and calculates the measured value of the tray position. is used to feedback-control the braking force command value, and when applying the braking force command value and the measured value to the current data, the two values of the tray position and the braking force command value included in the current data are calculated. Dimensional interpolation is performed to calculate the current command value corresponding to the braking force command value and the measured value.

According to the transport device, the braking force command value calculated by the driving device is calculated by feedback control using the tray position. The current command value supplied to the electromagnet for suppressing lateral displacement of the tray is a value calculated by applying the calculated braking force command value and the measured value of the tray position to the current data. It is a value calculated through two-dimensional interpolation between the tray position and the braking force command value at that time. As a result, the current value supplied to the electromagnet becomes a value reflecting the difference in the tray position, that is, a value reflecting the working distance between the electromagnet and the tray. As a result, even when braking force command values that are equal to each other are calculated, it is possible to supply current values that are different from each other, reflecting the spatial difference for applying the braking force. In addition, it is possible to suppress the occurrence of unstable behavior such as rocking in the horizontal direction in the tray.

In the conveying device, the drive device may include, as the current data, a table in which the current command value is associated with the tray position and the braking force command value.
According to this configuration, the current command value associated with the measured value of the tray position and the calculated braking force command value is calculated from the table that is the current data. Therefore, it is possible to supply a current value that reflects the spatial difference for applying the braking force.

In the conveying apparatus, the current data associates a larger current command value with the braking force command value as the braking force command value increases, and the current data increases as the distance between the tray and the electromagnet increases. A table may be included in which the large current command value is associated with the tray position.

According to this configuration, even when braking force command values that are equal to each other are calculated, the actual braking force that the electromagnet acts on the tray increases as the distance between the tray and the electromagnet increases. Therefore, it is possible to enhance the effectiveness of the effect of suppressing unstable behavior in the tray.

In the conveying device, the driving device calculates the braking force command value by adding an offset value that increases the braking force command value to the braking force calculated using the measured value of the tray position as a feedback value. may

When changing the current value of the electromagnet based on the feedback control of the braking force command value, there is a difference between the tray position when used to calculate the current command value and the tray position when the current is supplied. A deviation occurs due to a time lag between the time of supply and the time of supply. In this respect, according to the above configuration, the deviation of the braking force caused by the divergence of the tray position between the time of calculation and the time of supply is reduced by adding the offset value. As a result, it is possible to reduce the time required to converge the deviation between the tray position and the target position, and thus suppress the unstable behavior in the tray.

A vacuum processing apparatus for solving the above problems includes a vacuum chamber, a tray on which a substrate can be placed, and a transfer device for transferring the tray in the vacuum chamber, and the transfer device is the above-described It is a transport device.

According to the above-described vacuum processing apparatus, it is possible to prevent the tray from exhibiting unstable behavior such as rocking in the horizontal direction.

FIG. 2 is a top plan view of the internal structure in one embodiment of the vacuum processing apparatus; The side view which shows the side structure of a conveying apparatus. FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2; FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3; FIG. 2 is a block diagram functionally showing the configuration of a conveying device; 4 is a configuration diagram showing an example of offset data; FIG. The block diagram which shows an example of electric current data. FIG. 2 is a control block diagram functionally showing a configuration provided in a control unit of the conveying device; (a) to (d) are operation diagrams showing the operation of the transport process executed by the transport device. FIG. 4 is an operation diagram showing the operation of braking processing executed by the conveying device;

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

Each vacuum chamber 1 is equipped with a vacuum pump 1TP. The vacuum pump 1TP reduces the pressure inside the vacuum chamber 1 . Each vacuum chamber 1 shares a transport device 2 with other vacuum chambers 1 . The transfer device 2 carries 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 processes such as surface treatment, film formation, and heat treatment on the substrate S placed on the tray T. As shown in FIG.

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 communication and non-communication between two vacuum chambers 1 adjacent to each other. Each gate valve 1GV enables transfer of the tray T between two vacuum chambers 1 adjacent to each other.

As shown in FIG. 2 , the transport device 2 includes a transport section 10 and a guide section 20 . The transfer section 10 is located at the bottom of the vacuum chamber 1 . The guide part 20 is positioned at the top of the vacuum chamber 1 . The transport unit 10 and the guide unit 20 cooperate to transport the tray T in the front-rear direction while the substrate S is 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. As shown in FIG. Moreover, the direction orthogonal to the traveling direction X and the vertical direction Z is also called the left-right direction Y. As shown in FIG. A plurality of vacuum chambers 1 are arranged in the traveling direction X. As shown in FIG. The transport section 10 and the guide section 20 extend in the front-rear direction. The transport section 10 and the guide section 20 erect the substrate S substantially along the vertical direction Z. As shown in FIG.

[tray]
As shown in FIG. 2, the tray T comprises a tray top T1. The tray upper portion T1 has a rectangular frame shape surrounding the substrate S. As shown in FIG. The tray top T1 secures the substrate S to the tray top T1 using a plurality of clamps or the like. An upper end portion of the tray upper portion T1 is provided with a guided member 21A. The guided member 21A is a permanent magnet extending in the traveling direction X. As shown in FIG. The guided member 21A faces a portion of the guide portion 20 in the vertical direction Z. As shown in FIG.

As shown in FIG. 3, the tray T comprises a tray lower part T2. The lower tray T2 has a pair of left and right levitated magnets 11A. Further, the tray lower portion T2 is provided with a pair of braked portions 12A on the left and right.

The tray lower portion T2 has an inverted U shape in which the lower end portion is branched in the horizontal direction in a cross section including the horizontal direction Y and the vertical direction Z. As shown in FIG. The tray lower portion T2 has an inverted U-shaped cross section that is continuous in the front-rear direction. The tray lower portion T2 has a pair of left and right movable vertical walls FT, and a movable horizontal wall FB that spans the pair of movable vertical walls FT. The tray lower portion T2 supports the tray upper portion T1 on which the substrate S is placed.

The movable horizontal wall FB is joined to the lower end of the tray top T1. The two movable vertical walls FT extend downward from both left and right ends 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 horizontal direction Y. As shown in FIG. The position of the right movable vertical wall FT in the horizontal direction Y and the position of the left movable vertical wall FT in the horizontal direction Y are tray positions.

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

The right braked portion 12A is positioned on the right outer surface of the right movable vertical wall FT. The left braked portion 12A is located on the left outer surface of the left movable vertical wall FT. Each braked portion 12A is a ferromagnetic material. 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 has one scale 16A and one mover 13A. 13 A of movers function as a mover which comprises the linear motor 13. As shown in FIG. The mover 13A includes a yoke 13A1 and a pair of left and right transported magnets 13A2.

The yoke 13A1 has an inverted U shape in a cross section including the horizontal direction Y and the vertical direction Z. As shown in FIG. The yoke 13A1 exists intermittently along the front-rear direction. Each yoke 13A1 has a pair of left and right yoke vertical walls, and a yoke horizontal wall extending over 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 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 direction X of travel. The plurality of patterns to be read are arranged in the traveling direction X at regular intervals.

The right conveyed magnet 13A2 is positioned on the right inner surface of the right yoke vertical wall. The left transported magnet 13A2 is positioned on the left inner surface of the left yoke vertical wall. The plurality of transported magnets 13A2 are arranged in the front-rear direction over substantially the entire front-rear direction of the tray lower portion T2. The transported magnets 13A2 arranged in the front-rear direction are permanent magnets arranged with their magnetic poles alternately reversed in the front-rear direction.

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

The guiding member 21B and the guided member 21A are opposed to each other with different magnetic poles. The guide member 21B is a permanent magnet. The guiding member 21B applies a suction force to the guided member 21A so as to attract the tray T to the guiding portion 20. As shown in FIG. The suction force exerted by the guide member 21B suppresses the upper portion of the tray T from being displaced in the horizontal direction Y. As shown in FIG.

As shown in FIG. 3, the conveying section 10 has a pair of left and right braking rails 10A. Each braking rail 10A extends in the front-rear direction over the entire front-rear direction of the conveying section 10 .
The transport section 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 such 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. As shown in FIG.

A gap in the horizontal direction Y between the right braking rail 10A and each stator 10B is configured to accommodate the right movable vertical wall FT. A gap in the lateral 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 yoke vertical walls of the yoke 13A1.

The conveying unit 10 includes a pair of left and right levitation magnets 11B. The right levitation magnet 11B is located in the gap between the right braking rail 10A and the stator 10B. The left levitation magnet 11B is located in the gap between the left braking rail 10A 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 of the conveying section 10 .

The right levitation magnet 11B and the right levitation magnet 11A have the same magnetic poles facing each other. The left levitation magnet 11B and the left levitation magnet 11A also have the same magnetic poles facing 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 move the tray T away from the levitation magnet 11B. The repulsive force exerted by each levitation magnet 11B levitates the tray T by magnetic force.

Returning to FIG. 2, the transport section 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.

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 right braking magnet 12B is positioned to face the right movable vertical wall FT of the lower tray T2, and to face the right braked portion 12A when the tray T is floated. The left braking magnet 12B is positioned to face the left movable vertical wall FT of the lower tray T2, and to face the left braked portion 12A when the tray T is floated.

Each braking magnet 12B is an electromagnet whose driving is controlled by the driving device 30 . Each braking magnet 12B applies an attractive force to the braked portion 12A so as to attract the tray T to the braking magnet 12B. When the value of current flowing through each braking magnet 12B changes, the attractive force exerted by the braking magnet 12B changes. The attraction force exerted by each braking magnet 12B suppresses the displacement of the lower portion of the tray T in the horizontal direction Y. As shown in FIG.

Each stator 10B has a carrying magnet 13B1. Each carrying magnet 13B1 is positioned so as to face each yoke vertical wall of the yoke 13A1, and to face each carried magnet 13A2 when the tray T is floated. 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 transporting magnets 13B1 are arranged in the front-rear direction such that one or more transporting magnets 13B1 are sandwiched between two transported magnets 13A2.

Each transport magnet 13B1 is an electromagnet whose driving is controlled by the driving device 30 . The plurality of transfer magnets 13B1 function as stators forming a linear motor by changing the direction and magnitude of the current flowing through the transfer magnets 13B1. Each of the carrying magnets 13B1 and the carried magnets 13A2 constitute separate linear motors.

The transport section 10 includes a plurality of tray distance detection sections 15 . The plurality of tray distance detectors 15 are positioned 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 magnets 12B. The plurality of tray distance detection units 15 are arranged at intervals along the front-rear direction. The tray distance detector 15 positioned on the right brake rail 10A faces the right outer surface of the right movable vertical wall FT. The tray distance detector 15 positioned on the left braking rail 10A faces the left outer surface of the left movable vertical wall FT.

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

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

Each tray distance detector 15 outputs a measured value to the driving device 30 . The driving device 30 controls driving of each braking magnet 12B based on the distance in the horizontal direction between the braking magnet 12B and the movable vertical wall FT.

The distance in the left-right direction between the braking magnet 12B and the movable vertical wall FT may be calculated based on the measurement value of the tray distance detection unit 15 associated with the braking magnet 12B. The measured value of the tray distance detection unit 15 associated with the braking magnet 12B may be fictitious. Alternatively, the horizontal distance between the braking magnet 12B and the movable vertical wall FT is based on the measured values of the tray distance detection unit 15 associated with the braking magnet 12B and another tray distance detection unit 15. may be calculated by That is, the distance used to control the driving of the braking magnet 12B may be the measured value of the tray distance detection unit 15 or the estimated value obtained from the measured values of a plurality of tray distance detection units 15. good.

The transport section 10 includes a plurality of load sensors 13K. The load sensors 13K are arranged, for example, at intervals along the front-rear direction on the left inner surface of the left brake rail 10A. 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 photosensor that has a detection range above the stator 10B where the load sensor 13K is positioned, and detects the presence or absence of the tray T within the detection range.

Each load sensor 13K outputs a detection result to the driving device 30. FIG. The driving device 30 controls the driving of each braking magnet 12B based on the detection result of each load sensor 13K. The driving device 30 starts to drive the braking magnet 12B associated with each load sensor 13K based on the detection result of the load sensor 13K. The driving 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 detector 13B2 is positioned at the lower end of each stator 10B. One transport magnet 13B1 is associated with each presence/absence detector 13B2.

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 photosensor that includes a detection range above the stator 10B where the presence/absence detection unit 13B2 is positioned, and detects the presence/absence of the tray T within the detection range.

Each presence/absence detection unit 13 B 2 outputs the detection result to the drive device 30 . The driving device 30 controls driving of each gate valve 1GV based on the detection result of each presence/absence detection unit 13B2. The driving device 30 starts driving the transport magnets 13B1 associated with the presence/absence detection units 13B2 based on the detection results of the presence/absence detection units 13B2.

The transport section 10 includes a plurality of reading sections 16B. Each reading section 16B is positioned at the upper end of 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 such that one or more reading units 16B face the scale 16A. The plurality of reading units 16B are arranged in the front-rear direction such 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 with each transport magnet 13B1.

Each reading unit 16B reads a pattern to be read from the scale 16A when the scale 16A is positioned directly above the reading unit 16B. Each reading unit 16B outputs a count-up signal to the driving device 30 each time it reads one pattern to be read.

The scale 16A and each reading section 16B detect the relative position of the tray T with respect to the reading section 16B. The scale 16A and each reading section 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 are provided with 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 spaced in the front-rear direction.

The driving 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 driving device 30 controls driving of the transport magnet 13B1 associated with the reading section 16B based on the count value of the reading section 16B.

[Driving device]
As shown in FIG. 5 , the drive device 30 includes a control section 31 , a storage section 32 and a drive section 33 . The control unit 31 is configured by, 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 of the various processes by software.

For example, the control unit 31 may include an application specific integrated circuit (ASIC) that is dedicated hardware for executing at least part of the various types of processing. The control unit 31 may be configured as a circuit including one or more dedicated hardware circuits such as ASIC, one or more processors or microcomputers that operate according to software that is a computer program, or a combination thereof. good.

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

[data]
As shown in FIG. 6, the offset data 32B are 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 equal to or greater than 1). The offset value Ki is a compensation value added to the attraction force target value. The offset value Ki acts as a feedforward factor such as a feedforward proportional gain for disturbances dependent on the tray position Ym. The offset value Ki may be a value determined based on a test conducted in advance, or may be a value calculated using various parameters.

The target suction force value is calculated by feedback control such that the measured value of the tray position is used as a feedback value and the tray position is set to the target position. The suction force target value is calculated, for example, from the deviation between the speed for bringing the tray position to the target position and the measured value of the speed of the tray T in the horizontal direction. The offset value is a value for making the suction force command value higher than the suction force target value.

When the tray position is displaced in the configuration described above, the external force causing the tray position to deviate from the target position increases exponentially according to the amount of tray T displacement. This is mainly because the levitated magnets 11A and the levitation magnets 11B are permanent magnets, which is a factor that makes transportation of the tray T unstable, which is included in the above-described configuration.

For example, when the tray T is levitated with the same poles of magnets facing each other, a side force, which is a force that pushes the tray T in the horizontal direction, always acts on the tray T. Force increases. In the control in which the target value of the suction force to which the side force is not added acts as the suction force, the measurement of the tray position and the calculation of the target value of the suction force are performed before the tray T is moved by the suction force against the side force. This will be repeated many times, and it will take a long time to reach the target position of the tray.

The drive device 30 described above performs feedforward compensation for reducing such unstable factors and stably controlling the transport of the tray T. FIG. That is, the driving device 30 performs feedforward compensation using the offset value Ki that varies depending on the tray position as a feedforward proportional gain. The drive device 30 uses the tray position as an observer for estimating disturbances, and performs feedforward compensation for disturbances that depend on the amount of displacement of the tray T, such as compensation for disturbances due to side forces, in an appropriate and responsive manner. high compensation.

The offset data 32B associates, for example, the offset value K1 with the tray position Y1, the offset value K2 with the tray position Y2, and the offset value K3 with the tray position Y3. The offset data 32B associates, for example, the offset value K4 with the tray position Y4 and the offset value K5 with the tray position Y5.

The offset data 32B associates a larger offset value with the tray position, for example, as the tray position is further away from the braking magnet 12B. Further, the offset data 32B associates a constant value as an offset value, for example, when the distance in the horizontal direction Y between the tray position and the braking magnet 12B is less than or equal to a predetermined value.

For example, when the distance between the tray position Ym and the braking magnet 12B increases in the order of tray positions Y3, Y4, and Y5, the offset value Ki increases in the order of offset values K3, K4, and K5. Further, when the distances between the tray positions Y1, Y2 and the braking magnet 12B are equal to or less than a predetermined value and the distances between the tray positions Y3, Y4, Y5 and the braking magnet 12B are greater than the predetermined value, the 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 for a current value to be supplied to 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 horizontal position of the right movable vertical wall FT and the horizontal direction of the left movable vertical wall FT in a state in which the main surface of the substrate S is erected substantially along the vertical direction Z. is the position of

The current data 32A is a table in which current command values are associated with tray positions and suction force command values. 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.

The current data 32A associates a tray position Ym, a suction force command value Fn (n is an integer of 1 or more) with a current command value Cinm (n and m are integers of 1 or more). The current data 32A associates a larger current command value Cinm with the attraction force command value Fn as the attraction force command value Fn increases. Further, the current data 32A associates a larger current command value Cinm with the tray position Ym as the deviation between the tray position Ym and the target position becomes larger.

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

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

For example, when the presence/absence detection unit 13B2 detects arrival of the tray T, the control unit 31 starts supplying current to the transport magnet 13B1 associated with the presence/absence detection unit 13B2. Further, when the presence/absence detection unit 13B2 detects arrival of the tray T, the driving device 30 stops supplying the current to the transport magnets 13B1 associated with the presence/absence detection unit 13B2. As a result, the drive device 30 drives the plurality of transport magnets 13B1 according to the order in which they are arranged in the traveling direction X. As shown in FIG.

For example, the control unit 31 counts 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 a reference position. The global coordinate system is a coordinate system in which the reference positions of each local coordinate system are arranged in the order of the arrangement of the reading units 16B in the front-rear direction. That is, the global coordinate system is a one-dimensional coordinate system along the front-rear direction, and the position at which the transport is started, for example, is set as the reference position.

The control unit 31 transforms the position of the tray T in the local coordinate system into the position of the tray T in the global coordinate system. Based on the position of the tray T in the global coordinate system, the control section 31 controls the direction and magnitude of the current to be applied to each of the transfer magnets 13B1. That is, based on the transport position of the tray T, the controller 31 causes the transport magnets 13B1 and the transported magnets 13A2 to function as linear motors. Based on the position of the tray T in the global coordinate system, the control section 31 controls the direction and magnitude of the current to be applied to each braking magnet 12B.

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

The controller 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 left braking magnet 12B. 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 right braking magnet 12B. That is, the control unit 31 makes the measured value of the tray position and the target position to be used for calculation different between the calculation of the current command value on the left side and the calculation of the current command value on the right side. Below, the calculation of the current command value on the right side will be described in detail, and the redundant description of the configuration for the calculation of the current command value on the left side will be omitted.

The input unit 41 inputs a target 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 to calculate 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 the positional deviation on the right side.

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

The speed counter 46 uses the measured value of the tray position on the right side as a feedback value, and calculates the measured value of the current tray speed using the measured value of the tray position this time 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 section 42 and the measured value of the tray speed this time as the speed deviation on the right side.

The speed control unit 43 calculates the attraction force for zeroing the speed deviation on the right side output from the adder/subtractor 42A. The speed control unit 43 outputs the calculated attraction force as the attraction force target value for the right side.

The attraction force determination unit 44 determines whether or not the attraction force target value is less than zero. When the attraction force determination unit 44 determines that the attraction force target value is equal to or greater than zero, the attraction force determination unit 44 outputs the attraction force target value to the adder 44A. When the attraction force determination unit 44 determines that the attraction force target value is smaller than zero, it outputs the attraction force target value as zero to the adder 44A. That is, the attraction force determination unit 44 determines whether the force corresponding to the target attraction value is the attraction force or the repulsive force. is output to the adder 44A, and if it is determined to be a repulsive force, the attraction force target value is set to zero and output to the adder 44A.

The offset value calculator 47 outputs an offset value based on the tray position measurement value using the tray position measurement value and the offset data 32B. At this time, the offset value calculator 47 performs interpolation processing using the offset data 32B, thereby outputting the 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 linear interpolation such as linear interpolation, polynomial interpolation, or spline interpolation between the tray positions Ym included in the offset data 32B. Outputs a continuous offset value. The adder 44A outputs the addition value of the attraction force target value on the right side and the offset value output by the offset value calculator 47 as the attraction force command value Fn.

The current command value calculator 45 uses the attraction force command value Fn output by the adder 44A, the measured value of the tray position, and the current data 32A to calculate the current command value based on the attraction force command value Fn and the measured value. Calculate At this time, the current command value calculator 45 performs a two-dimensional interpolation process using the attraction force command value Fn and the measured value of the tray position. A current command value Cimm is calculated. 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 , performs spline interpolation, thereby outputting a continuous current command value that is not discrete. The current command value calculator 45 outputs the calculated current command value to the driver 33 . The driving unit 33 detects the current value supplied to the right braking magnet 12B, and feedback-controls the current value supplied to the right braking magnet 12B so that the current value becomes the current command value.

[Action 1: Conveying process]
Next, an example of the transporting process executed by the driving device 30 will be described with reference to FIG. 9 . An example in which two trays T are continuously transported on one path in which three reading units 16B are arranged in the traveling direction X will be described below. Note that FIG. 9 shows an example in which the distance between the presence/absence detecting portion 13B2, the transport magnet 13B1, and the reading portion 16B 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 section 16B and the position of each tray T in a one-dimensional global coordinate system extending in the traveling direction X. FIG. Also, the coordinate values of the tray T in each local coordinate system are shown above the coordinate axes. Also, the coordinate values of the transport position in the global coordinate system are shown below the coordinate axes. Hereinafter, coordinate values in the local coordinate system are also referred to as local coordinates, and 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. As shown in FIG. The reading units 16B located at the coordinate values YB1, YB2, and YB3 are also called the first reading unit 16B1, the second reading unit 16B2, and the third reading unit 16B3, respectively.

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

As shown in FIG. 9A, when the leading end of the tray T in the traveling direction X reaches the coordinate value YB1, the first presence/absence detection unit detects that the tray T has arrived. The driving device 30 starts supplying current to the first transfer magnet based on the detection result of the first presence/absence detection unit. Next, when the tip of the tray T in the traveling direction X begins to pass the coordinate value YB1, the control section 31 counts up the count value of the first reading section 16B1 from "0".

During this time, the driving 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 transport magnet, and the , change the size. As a result, the driving device 30 transports the tray T in the traveling direction X. As shown in FIG. Further, the driving 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 current to the identified 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 a predetermined position at a predetermined transport speed. Control. Further, the control unit 31 controls driving of the braking magnet 12B based on the detection result of the load sensor 13K. Note that 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 to the local coordinates of the first encoder.

As shown in FIG. 9B, when the tip of the tray T in the traveling direction X reaches the coordinate value YB2, the second presence/absence detector detects that the tray T has arrived. Then, based on the detection result of the second presence/absence detection unit, the driving device 30 starts supplying the current to the second carrier magnet and stops supplying the current to the first carrier magnet. Further, the control unit 31 sequentially counts up the count value of the second reading unit 16B2 from "0", and sets "1000" which is the global coordinate when the count value of the second reading unit 16B2 is "0". Compensation value.

During this time, the driving 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. FIG. Based on the global coordinates of the tray T, the driving device 30 changes the direction and magnitude of the current supplied to the second transfer magnet. As a result, the driving device 30 further transports the tray T in the traveling direction X. As shown in FIG. Further, the driving device 30 identifies 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 identified braking magnet 12B. When the control unit 31 starts converting the count value of the second reading unit 16B2 into the global coordinates, the control unit 31 resets the count value of the first reading unit 16B1 to "0".

That is, when switching the target of action on the mover 13A from the first conveying magnet to the second conveying magnet, the control unit 31 changes the conversion source of the global coordinates from the local coordinates by the first reading unit 16B1 to the second reading unit 16B1. Switch to local coordinates by the unit 16B2. At this time, the control unit 31 adds a compensation value to the local coordinates obtained 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. FIG. Note that 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 driving device 30 converts the count value of the second reading section 16B2 to the global coordinates of the tray T even while the tray T is passing 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 addition result is used as the global coordinates of the tray T. Then, the driving device 30 changes the direction and magnitude of the current supplied to the second carrying magnet based on the conversion result of the count value of the second reading section 16B2. As a result, the driving device 30 transports the tray T in the traveling direction X. As shown in FIG. Further, the driving device 30 identifies 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 identified braking magnet It controls the driving of 12B.

For example, if the count value of the second reading unit 16B2 is "500", the result obtained by adding the compensation value "1000" to the count value "500" of the second reading unit 16B2 is A certain "1500" is used as the global coordinates of the tray T. Then, the driving device 30 changes the direction and magnitude of the current supplied to the second carrying magnet based on the fact that the global coordinates of the tray T are "1500". Further, the driving device 30 changes the magnitude of the current supplied to the braking magnet 12B based on the fact that the global coordinates of the tray T are "1500".

As shown in FIG. 9D, in the driving device 30, the third presence/absence detection unit detects arrival of the tray T when the leading end of the tray T in the traveling direction X reaches the coordinate value YB3. Then, based on the detection result of the third presence/absence detection unit, the driving device 30 starts supplying current to the third carrier magnet and stops supplying current to the second carrier magnet. Further, the control unit 31 sequentially counts up the count value of the third reading unit 16B3 from "0", and sets "2000" which is the global coordinate when the count value of the third reading unit 16B3 is "0". Compensation value.

During this time, the driving 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. Based on the global coordinates of the tray T, the drive device 30 changes the direction and magnitude of the current supplied to the third transfer magnet. Further, the driving device 30 identifies 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 identified braking magnet 12B. As a result, the driving device 30 further transports the tray T in the traveling direction X. As shown in FIG. When the control unit 31 starts converting the count value of the third reading unit 16B3 into global coordinates, the control unit 31 resets the count value of the second reading unit 16B2 to "0".

That is, when switching the target of action on the mover 13A from the second conveying magnet to the third conveying magnet, the control unit 31 changes the conversion source of the global coordinates from the local coordinates by the second reading unit 16B2 to the third reading unit 16B2. Switch to local coordinates by the unit 16B3. At this time, the control unit 31 adds a 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. FIG.

Note that when the leading end of the succeeding tray T in the traveling direction X 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 driving device 30 starts supplying the current to the first transfer magnet again. Also, when the leading edge of the succeeding tray T in the traveling direction X begins to pass the coordinate value YB1, the control section 31 again counts up the count value of the first reading section 16B1 from "0". Then, the control unit 31 repeats the drive control of each reading unit 16B, each transporting magnet 13B1, and each braking magnet 12B in the same manner as the preceding tray T. FIG.

[Action 2: Braking process]
When controlling the drive of the right braking magnet 12B, the control section 31 inputs the measured value output by the right tray distance detection section 15, and controls the right braking magnet 12B corresponding to the tray distance detection section 15. The driving of the magnet 12B is controlled based on the measured value of the tray distance detection section 15. FIG. Similarly, when controlling the driving of the left braking magnet 12B, the control section 31 inputs the measured value output by the left tray distance detecting section 15, and controls the driving of the left braking magnet 12B to the left braking magnet 12B. Control is performed based on the measured value of the tray distance detection unit 15 .

That is, the controller 31 uses the measured value of the tray position on the right side as a feedback value, and 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. do. Similarly, the control unit 31 uses the measured value of the tray position on the left side as a feedback value, and calculates 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 measurement value by the right tray distance detection unit 15 and the offset data 32B to calculate the offset value Ki based on the measurement value as the offset value to be applied to the right braking magnet 12B. do. Then, the control unit 31 calculates the addition value of the attraction force target value on the right side and the offset value on the right side as the attraction force command value on the right side. Further, the control unit 31 uses the measurement value by the left tray distance detection unit 15 and the offset data 32B to calculate the offset value Ki based on the measurement value as the offset value to be applied to the left braking magnet 12B. do. Then, the control unit 31 calculates the sum of the left side attraction force target value and the left side offset value as the left side attraction force command value.

Next, the control unit 31 calculates a current command value to be applied to the right braking magnet 12B and a current command value to be applied to the left braking magnet 12B using the common current data 32A. That is, the control unit 31 uses the measurement value by the right tray distance detection unit 15, the right suction force command value, and the current data 32A to determine the measurement value by the right tray distance detection unit 15 and the right suction force. A current command value is calculated based on the command value. Further, the control unit 31 uses the measurement value by the left tray distance detection unit 15, the left suction force command value, and the current data 32A to determine the measurement value by the left tray distance detection unit 15 and the left suction force. A current command value is calculated based on the command value.

Thus, the attraction force command value Fn calculated by the driving device 30 is calculated by feedback control using the tray position Ym. The current command value Cinm calculated by the driving device 30 is calculated using the calculated attractive 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 detector 15 and the tray T, that is, the working distance W between the braking magnet 12B and the tray T. is a value that reflects

Also, the attractive force command value Fn for generating the current command value Cinm is the sum 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 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 has a magnitude that brings the tray position Ym closer to the target position by the offset value Ki.

As described above, according to the above embodiment, it is possible to obtain the following effects.
(1) Between the case where the attractive force command value Fn is calculated at the tray position close to 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 distance of the attraction force that the magnet 12B exerts on the tray T differs from each other. Such a spatial difference for applying the attraction force can be reduced by calculating the current command value Cinm associated with the tray position Ym. As a result, it is possible to prevent the tray from exhibiting unstable behavior such as swinging in the horizontal direction.

(2) Since the current command value Cinm associated with the measured value of the tray position and the attraction force command value Fn is calculated from the table, it is possible to improve the feasibility of obtaining the effect according to the above (1). It becomes possible.

(3) Further, the actual attractive force acting on the tray T by the braking magnet 12B decreases as the distance between the tray T and the braking magnet 12B increases. Therefore, if the current data 32A associates a larger current command value Cinm with the tray position Ym as the distance between the tray T and the braking magnet 12B increases, the effect according to the above (1) can be obtained. It is also possible to further improve performance.

(4) An offset value Ki that varies with tray position is used as a feedforward proportional gain. Therefore, it is possible to appropriately compensate for a disturbance such as a side force that causes the tray position to deviate from the target position with high responsiveness.

(5) As the distance between the tray T and the braking magnet 12B increases, the offset value Ki can be increased and, in turn, the attractive force can be increased. It is possible to improve the effectiveness of

(6) 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 kept constant. Excessive force can be suppressed.

(7) Since the global coordinates of the tray T are converted from the local coordinates of each reading unit 16B provided in the transport unit 10, the signal cable for transmitting the output of the encoder is used to transport the tray T instead of the tray T. It becomes possible to connect to a 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.

(8) 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 can increment the local coordinates for the next tray T. Therefore, it is possible to apply such a conveying device 2 even to a mass-production machine that is required to convey a plurality of trays T continuously.

(9) Switching the conversion target from the local coordinates of the first reading unit 16B1 to the local coordinates of the second reading unit 16B2 means switching from driving the first conveying magnet to driving the second conveying magnet; That is, it is performed at the same time as the switching of the action target with respect to the mover 13A. This makes it possible to match the switching of the conversion target and the switching of the effect target. As a result, for example, the conversion target is not switched even though reading by the first reading unit 16B1 is disabled, or the conversion target is switched even though reading by the second reading unit 16B2 is disabled. It is suppressed from occurring. That is, it is possible to suppress the occurrence of an error in the global coordinates due to the mismatch between the switching of the object to be transformed and the switching of the object to be operated.

(10) Further, it becomes possible to more smoothly switch the conversion target from the local coordinates of the first reading unit 16B1 to the local coordinates of the second reading unit 16B2.
(11) It is also possible to convert the local coordinates of the second reading unit 16B2 by a simple operation of adding the global coordinates at the time of switching the conversion target and the local coordinates output by the second reading unit 16B2.

(12) 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 detection of the presence/absence of the tray T by the second presence/absence detection unit. As a result, the object to be converted is switched based on whether or not the tray T actually exists. It is also possible to suppress the switching of the conversion target despite the fact that reading by the second reading unit 16B2 is impossible. That is, it is possible to suppress the occurrence of an error in the global coordinates due to the mismatch between the switching of the conversion target and the switching of the reading unit.

It should be noted that the above embodiment can be implemented with the following modifications.
[Current data]
- The current data 32A can be changed into various arithmetic expressions. The arithmetic expression is a relational expression between the tray position Ym, the attraction force command value Fn, and the current command value Cinm, which enables the calculation of the current command value Cimm from the tray position Ym and the attraction force command value Fn. . The point is that the current data 32A may be configured so that the current command value that compensates for the spatial difference, ie, the difference in the distance in which the braking force acts, can be calculated from the tray position and the attraction force command value.

- Part of the current data 32A may correspond to a plurality of combinations of the tray position Ym and the attractive force command value Fn with mutually equal current command values Cinm. For example, a constant current command value Cinm may be associated with a plurality of tray positions Ym for a range of tray positions Ym in the vicinity of the target position.

[Offset data]
- The offset data 32B can be changed to various arithmetic expressions. The arithmetic expression is a relational expression between the tray position Ym and the offset value Ki that enables calculation of the offset value Ki from the tray position Ym. In short, the offset data 32B may be configured so that 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 forming the offset data 32B can be changed to larger values as the tray position Ym is further away from the braking magnet 12B.
- The offset value Ki forming the offset data 32B is not limited to a value that makes the attraction force command value higher than the attraction force target value. For example, if the position control unit 42 and the speed control unit 43 are configured so that a target suction force value greater than the actual suction force is always calculated, the suction force command value is set higher than the target suction force value. The offset data 32B is composed of the offset value Ki that decreases.

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

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

The offset data 32B can be modified so that a constant value is associated as the offset value Ki within a range in which the distance in the horizontal direction Y between the tray position Ym and the braking magnet 12B is equal to or greater than a predetermined value.

[encoder]
- The scale 16A is not limited to an incremental linear scale, and 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 horizontal direction, and has an outer peripheral surface in which mutually different magnetic poles are alternately repeated along the circumferential direction. The stator 10B is configured to advance the mover 13A in the traveling direction X following the rotation of the rotating body. 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 not on the tray T but on the stator 10B. With this configuration, the scale 16A can be omitted from the tray T, and the configuration of the tray T can be simplified.

[Braking force]
In the above embodiment, an example was described in which the braking force for arranging the tray position at the target position is the attraction force that attracts the tray T toward the braking magnet 12B. Without being limited to this, the braking force for arranging the tray position at the target position may be a repulsive force that moves 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, the magnetic force acting on the braked portion 12A changes from attractive force to repulsive force, or from repulsive force to attractive force, when the direction of the current flowing through the braking magnet 12B changes. Therefore, the combination of the braked portion 12A and the braking magnet 12B may be configured to be positioned only on either the right side or the left side of the tray T in the left-right direction.
- In the above-described embodiment, an example in which one tray distance detection unit 15 is associated with one braking magnet 12B has been described. By changing this, the interval between the mutually adjacent tray distance detectors 15 and the interval between the mutually adjacent braking magnets 12B 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 detector 15 . At this time, the driving device 30 has, for example, coordinate values of each braking magnet 12B in the global coordinate system. Further, the driving device 30 identifies the braking magnets 12B whose distance between the conveying position of the tray T and the braking magnets 12B is equal to or less than a predetermined value. Then, the driving device 30 controls driving of the specified braking magnet 12B so as to suppress displacement of the tray T in the left-right direction.

For example, two or more tray distance detectors 15 may be associated with one braking magnet 12B. At this time, the driving device 30 has, for example, coordinate values of each braking magnet 12B in the global coordinate system. Further, the driving device 30 identifies the braking magnets 12B whose distance between the conveying position of the tray T and the braking magnets 12B is equal to or less than a predetermined value. Then, the driving device 30 identifies the attitude of the tray T from the measured values of the tray distance detection units 15, and controls the driving of the identified braking magnets 12B so as to suppress lateral displacement of the tray T. .

- The tray distance detection unit 15 may be configured to be positioned only on one of the left and right sides of the tray T between them. The distance between the braking magnets 12B in the horizontal direction and the width of the tray T in the horizontal direction can be known in advance. It is possible to calculate the distance on the other side.

[others]
- The guided member 21A may be a magnetic body that is attracted to the guide portion 20 . In short, it is sufficient that the guided member 21A is displaced upward in the vertical direction Z by receiving the magnetic force exerted by the guide portion 20 .

- The guide member 21B may be a magnetic body that attracts the tray T. The point is that the guide member 21B should be configured to displace the guided member 21A upward in the vertical direction Z by receiving the magnetic force exerted by the guided member 21A.

- The braked portion 12A may be a magnetic body that is attracted to the braking magnet 12B. The point is that the braked portion 12A is configured to receive the magnetic force exerted by the braking magnet 12B and displace the braked portion 12A in the left-right direction.

- The drive device 30 may have a configuration in which the presence/absence detector 13B2 is omitted. At this time, the drive device 30 has, for example, global coordinates of each of the transport magnets 13B1. Then, the driving device 30 identifies the transport magnet 13B1 whose 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 identifies the braking magnet 12B facing the tray T among the plurality of braking magnets 12B based on the count value of the first reading section 16B1, and drives the identified braking magnet 12B. to control.

- The mover 13A mounted on the tray T may be an electromagnet, and the transfer magnet 13B1 may be a permanent magnet extending in the front-rear direction. At this time, the driving device 30 conveys the tray T in the traveling direction X by controlling the driving of the mover 13A. Even with this configuration, it is possible to obtain the effects corresponding to the above (1) to (6).

The control unit 31 omits the calculation of the offset value Ki using the offset data 32B and the addition of the attraction force target value and the offset value Ki, and changes the configuration so that the attraction force target value is the attraction force command value Fn. It is possible. Even with this configuration, it is possible to obtain the effects corresponding to the above (1) to (3) and the above (7) to (12).

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

Ci11, Ci12, Ci13, Ci21, Ci31, Cinm... current command value, K1, K2, K3, K4, K5, Ki... offset value, S... substrate, T... tray, Y1, Y2, Y3, Y4, Y5, Ym Tray position 1 Vacuum chamber 2 Conveying device 10 Conveying unit 30 Driving device 32A Current data 32B Offset data.

Claims (5)

a transport unit that transports a tray on which a substrate can be placed in the front-rear direction while magnetically levitating;
a measuring unit that measures a tray position, which is the position of the tray in the horizontal direction;
a suppressing unit that suppresses a change in the tray position by a braking force of an electromagnet;
a driving device that calculates a braking force command value for placing the tray position at a target position and converts the braking force command value into a current command value for the electromagnet;
The driving device
current data for obtaining the current command value for arranging the tray position at the target position from the tray position and the braking force command value, and using the measured value of the tray position, the braking force command value is feedback-controlled, and when applying the braking force command value and the measured value to the current data, two-dimensional interpolation is performed between the tray position and the braking force command value included in the current data to obtain the A conveying device that calculates the current command value corresponding to the braking force command value and the measured value. 2. The conveying apparatus according to claim 1, wherein the driving device includes, as the current data, a table in which the current command value is associated with the tray position and the braking force command value. The current data associates a larger current command value with the braking force command value as the braking force command value is larger, and a larger current command value is associated with the braking force command value as the distance between the tray and the electromagnet becomes longer. 3. The conveying apparatus according to claim 1, further comprising a table in which current command values are associated. 4. The driving device calculates the braking force command value by adding an offset value that increases the braking force command value to the braking force calculated using the measured value of the tray position as a feedback value. The transport device according to any one of Claims 1 to 3. a vacuum chamber;
a tray on which the substrate can be placed;
a transport device for transporting the tray in the vacuum chamber,
A vacuum processing apparatus, wherein the transfer device is the transfer device according to any one of claims 1 to 4.

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