JP2013197454A - Transfer control device, transfer system, reference table creation method, and holding position calibration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer control device which efficiently identifies deviation of a substrate holding position when transferring a substrate.SOLUTION: A transfer control device 10 controlling a transfer mechanism 20 which transfers a substrate 60 includes: a reception section for acquiring a signal indicating passage timing of the substrate in the middle of a substrate transfer path by the transfer mechanism 20; a substrate position acquisition section for acquiring deviation of a holding position of the substrate 60 by referring to a reference table on the basis of the timing of the signal acquired by the reception section; the reference table for recording a plurality of holding positions of the substrate 60 with respect to a holding part 26 in association with the timing of the signals indicating passage of the substrate when the transfer mechanism 20 holds the substrate 60 at the respective holding positions and transfers the substrate; and an operation control section for correcting a transfer operation of the transfer mechanism 20 on the basis of the deviation of the holding position of the substrate 60 acquired by the substrate position acquisition section and transferring the substrate 60 to a target position.

Description

  The present invention relates to a substrate transfer technique, and more particularly to a technique for specifying a shift amount of a substrate holding position of a transfer mechanism.

In the semiconductor integrated circuit manufacturing process, hundreds of processes are performed on a substrate such as a silicon wafer. The substrate is transferred between various substrate processing apparatuses, substrate storage cassettes, and the like by a transfer mechanism such as a robot arm.
If the substrate is placed at a position deviated from the correct placement location for some reason, is gripped, or moves on the gripping part during transport, the transport mechanism grips the substrate at a position deviated from the normal gripping position. Will be transported as is. As a result, the substrate cannot be accurately placed at the transfer target position, which may affect the product yield, and may cause problems such as damage to the substrate or stop of the apparatus.

  For this reason, various methods have been proposed for detecting and calibrating the displacement of the holding position of the substrate being transported. Patent Document 1 describes a substrate processing apparatus that detects a substrate being transferred using a plurality of sensors and determines the eccentricity of the substrate with respect to a desired position on an end effector of a robot manipulator. According to this technique, the timing at which the substrate being transferred passes in front of the sensor is detected. Since the positions of the robot, the transfer destination station, and the sensor are strictly measured in advance, the eccentricity of the substrate can be calculated from the passage timing. The stop position of the end effector of the robot manipulator is controlled so as to correct the displacement based on the calculation result.

Special table 2009-500869 gazette

  In order to realize the above-described technology, as a precondition, it is necessary that an apparatus, a transport mechanism, a sensor, and the like serving as a transport start point and a transport target point are accurately positioned. For positioning, accuracy of about 0.1 mm is required, but the other components, each having a certain size and complexity, are accurately positioned on the floor or on the base on which the components are mounted. It is not always easy to place. For this reason, after positioning the device and sensor once, a laborious and time-consuming preparatory work is performed such that the trial operation of the transport mechanism is repeated and the error of the installation position is corrected by trial and error.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a transport control device, a transport system, a reference table creation method, and a gripping position calibration method that can efficiently specify a shift amount of a substrate gripping position. There is.

  In order to solve the above-described problems, a transport control device according to an aspect of the present invention is a transport control device that controls a transport mechanism that transports a substrate, and shows a passage timing of the substrate in the middle of a substrate transport track by the transport mechanism. A receiving unit that acquires a signal, a storage unit that stores a reference table used for specifying a positional deviation amount when the substrate gripping unit of the transport mechanism grips the substrate, and a reference table based on the timing of the signal acquired by the receiving unit , And a substrate position acquisition unit that specifies the amount of positional deviation of the substrate. The reference table correlates a plurality of known positions of the substrate with respect to the substrate gripping unit and the timing of signals acquired by the receiving unit when the substrate is gripped and transported at each position.

  According to this aspect, for example, the shift amount of the substrate gripping position of the transport mechanism can be obtained using a table created in advance based on actual measurement values.

  Another aspect of the present invention is a transport system. This transport system is a transport system that includes a transport mechanism that transports a substrate, a sensor that emits a signal when the passage of the substrate is detected, and a transport control device that controls the transport mechanism. Referring to the reference table based on the timing of the signal generated by the sensor and the storage unit that stores the reference table used to specify the amount of positional deviation when the substrate gripping part of the mechanism grips the board, specify the amount of positional deviation of the board A substrate position acquisition unit. The reference table associates multiple positions of the substrate with respect to the substrate gripping unit and the timing of the signal generated by the sensor when the substrate is gripped and transported at each position, and the transport mechanism is specified by the substrate position acquisition unit The transport operation is corrected based on the amount of positional deviation of the substrate, and the substrate is transported to the transport target position.

  According to this aspect, for example, the deviation amount of the substrate gripping position of the conveyance mechanism can be obtained using a table created in advance based on actual measurement values, and the substrate can be more accurately conveyed to the target position based on the obtained deviation amount. it can.

  Yet another embodiment of the present invention is a reference table creation method. This method is a method for creating a reference table used for specifying a positional deviation amount of a substrate in a transport control system including a transport mechanism for transporting a substrate, a sensor for detecting passage of the substrate, and a transport control device. The transfer control device stores the transfer start position of the transfer mechanism, the substrate transfer trajectory, and the transfer target position, and the transfer mechanism grips the substrate placed at the transfer start position by a known deviation amount. A step of transporting the substrate toward the transport target position, a step of acquiring a signal generated when the sensor detects passage of the substrate, and a transport control device. Storing the timing of the acquired signal and the known deviation amount in association with each other.

  According to this aspect, for example, the table used when determining the shift of the substrate gripping position of the transport mechanism can be created by the automatic operation of the transport mechanism.

  Yet another aspect of the present invention is a gripping position calibration method. This method is a method for calibrating the positional deviation of the substrate held by the transport mechanism with reference to the reference table, and the transport control device acquires a signal generated by the sensor while the transport mechanism transports the substrate; The transport control device refers to the reference table based on the timing of the acquired signal, specifies the amount of substrate misalignment, and the transport mechanism corrects the transport operation based on the substrate misalignment, And a step of conveying to a conveyance target position.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the shift | offset | difference of the board | substrate holding position at the time of conveying a board | substrate can be pinpointed efficiently.

It is a figure which shows typically the conveyance control system concerning an Example. It is a figure which shows the structure of the conveyance control apparatus concerning an Example. FIGS. 3A and 3B illustrate signal timing from the sensor when the transport mechanism according to the embodiment grips the substrate at the reference grip position and transports the substrate along the reference transport track to the substrate cassette. It is a figure for doing. 4A and 4B show signal timings from the sensor when the transport mechanism grips the substrate at a position shifted in a direction parallel to the traveling direction with respect to the gripping portion and transports the substrate to the substrate cassette. It is a figure for demonstrating. FIG. 5A and FIG. 5B show signal timings from the sensor when the transport mechanism grips the substrate at a position shifted in the direction perpendicular to the traveling direction with respect to the gripping portion and transports the substrate to the substrate cassette. It is a figure for demonstrating. It is a figure which shows the example of the reference | standard table concerning an Example. It is a figure which shows the example of the some conveyance track | line which can be selected when a conveyance mechanism conveys a board | substrate. It is a figure which shows the reference | standard table preparation process of a conveyance control apparatus. It is a figure which shows the board | substrate holding | grip position calibration process of a conveyance control apparatus.

First, an outline will be described.
In this embodiment, as a preparatory work for obtaining the deviation of the substrate gripping position during transport, the transport mechanism learns after the device, transport mechanism, sensor, and the like that are the transport start point and transport target point are installed at a desired position. Do the driving.
During the learning operation, the transport mechanism reciprocates the transport path while gradually shifting the substrate gripping position, and the transport control device records the timing at which the sensor detected the substrate during that time, and the substrate gripping position shift and sensor signal timing Create a reference table that associates
When the sensor detects the passage of the substrate and issues a signal during actual substrate conveyance, the conveyance control device refers to the reference table based on the timing and obtains the deviation of the substrate gripping position. The transport mechanism can transport the substrate to the original target position by correcting the scheduled operation so as to compensate for the shift of the substrate gripping position.
In this embodiment, since the position where the apparatus and the sensor are actually installed is reflected in the reference table, an error in the installation position of the apparatus and the sensor at the manufacturing site can be absorbed.

This will be specifically described below.
FIG. 1 schematically shows a transport control system 70 according to the embodiment.
The transport control system 70 is installed on a track on which a substrate 60 is transported, a transport mechanism 20 that transports the substrate 60 between a substrate processing apparatus 40 that processes the substrate 60 such as a wafer, and a substrate cassette 50 that accommodates the substrate 60. Sensors 30a and 30b (hereinafter collectively referred to as "sensor 30") that detect the passage of the substrate and generate a signal indicating the passage timing of the substrate, receive signals from the sensor 30, and operate the transport mechanism 20 A transport control device 10 for controlling is provided.

  The transport mechanism 20 is rotatably attached to a base portion 22 that is movable with respect to the floor, a first arm that is rotatably attached to the rotation shaft of the base portion 22, and a rotation shaft at the tip of the first arm. An arm portion 24 including a second arm, and a grip portion 26 rotatably attached to a rotation shaft at the tip of the second arm. The gripping unit 26 grips the substrate using an electrostatic chuck, a vacuum chuck, a mechanical holding mechanism, a frictional force, or the like (not shown). Note that the base portion 22 may be fixed to the floor on which it is installed.

  The sensor 30 includes a radiation part (not shown) that emits a light beam to the transport path of the substrate, and a detection part (not shown) provided at a position that receives the light beam from the radiation part across the transport path. . The sensor 30 emits a signal when the front edge of the substrate transported along the transport track by the transport mechanism 20 blocks the light beam, that is, when the substrate non-detection state is switched to the substrate detection state.

Note that the sensor 30 may include a radiation unit, a reflection unit that reflects a light beam from the radiation unit across the conveyance path, and a light receiving unit provided at a position that receives light from the reflection unit. In this case, the radiation part and the light receiving part may be formed integrally.
In addition, the sensor 30 moves when the trailing edge of the substrate moving along the transport path passes through the light beam radiation region and the light beam shielded by the substrate is detected again, that is, from the substrate detection state to the substrate non-detection state. A signal may also be issued when switching to.
In addition, the sensor 30 may be an infrared sensor or an ultrasonic sensor, and may be any sensor that can detect the passage of the conveyance target.

FIG. 2 shows a configuration of the transport control apparatus 10 according to the embodiment.
When the conveyance control device 10 obtains an instruction acquisition unit 100 that acquires an instruction to execute substrate conveyance or a learning operation from a user or the like, a reception unit 102 that acquires a signal indicating the substrate passage timing from the sensor 30, and a shift amount of the substrate gripping position The table creation unit 120 for creating the reference table 130 referred to in the above, the storage unit 104 for storing the reference table 130, the trajectory information acquisition unit 106 for obtaining the trajectory information for specifying the substrate transport trajectory, and the reference table 130 at the time of substrate transport In addition, a substrate position acquisition unit 108 that determines the amount of substrate misalignment, and an operation control unit 110 that controls the transport mechanism 20 during substrate transport or learning operation are provided.

  The operation control unit 110 calculates a correction value for the movement target position of the gripping unit 26 of the transport mechanism 20 based on the amount of displacement of the substrate obtained by the substrate position acquisition unit 108, substrate transport and learning. A command unit 114 that sends an operation command to the transport mechanism 20 during operation, and a trajectory setting unit 116 that sets a reference transport trajectory (hereinafter also referred to as “reference trajectory”) when the learning operation starts.

  The reference trajectory is typically an actual trajectory for transporting a substrate, but may be a trajectory that is not used for actual transport. As described later, a plurality of substrate transport trajectories may be used. In some cases, it may be one of them.

  The instruction acquisition unit 100 acquires an instruction from a user via an operation unit (not shown) including a switch, a keyboard, a pointing device such as a mouse and a trackball, a touch panel, and a microphone.

  When the instruction for creating the reference table 130 is acquired from the user, the instruction acquisition unit 100 sends a trajectory setting instruction to the trajectory setting unit 116 of the operation control unit 110. The trajectory setting unit 116 sets the trajectory input from the user by a general method used as the trajectory setting method of the transport mechanism as a reference trajectory used when creating the table, and stores it in the storage unit 104 as attribute information of the reference table 130. . For example, the user places and holds the substrate 60 at a position where the substrate 60 should be gripped on the gripping portion 26 (hereinafter referred to as “reference gripping position”), and in that state, the arm portion 24, the gripping portion 26, the base portion The desired trajectory is input by manually operating 22 and moving the substrate 60 from the transfer start position of the substrate processing apparatus 40 to the target position of the substrate cassette 50. The trajectory setting unit 116 stores the trajectory of the gripping unit 26 at this time in the storage unit 104 as a reference trajectory.

  The reference gripping position is, for example, a gripping position recommended for the design of the transport mechanism 20. Alternatively, it may be a desired position specified by the user in accordance with the form of the substrate installation location at the transfer start position or the transfer target position.

When the reference trajectory is set, the command unit 114 of the operation control unit 110 sends a transport start command to the transport mechanism 20, moves the gripper 26 along the reference trajectory, and transports the substrate 60.
3A and 3B show signal timings from the sensor 30 when the transport mechanism 20 grips the substrate 60 at the reference grip position and transports the substrate 60 to the substrate cassette 50 along the reference trajectory. .

  In FIG. 3B, when the sensor 30a detects the front edge of the substrate when the command unit 114 transports the transport mechanism 20 to the transport mechanism 20 at the time origin T0 and the reference gripping position. Is indicated as Ta0, and the time when the sensor 30b detects the front edge of the substrate is indicated as Tb0. The same applies to FIGS. 4B and 5B described later.

The table creation unit 120 stores the signal timings Ta0 and Tb0 in the storage unit 104 as attribute information of the reference table 130.
When the substrate 60 reaches the transfer target position, the gripper 26 releases the substrate 60 and accurately places it at the transfer target position.

Next, the command unit 114 reciprocates the reference trajectory while gradually shifting the substrate gripping position to the transport mechanism 20, and the table creating unit 120 creates the reference table 130 by relating the sensor signal timing and the substrate gripping position.
Specifically, in response to a command from the command unit 114, the transport mechanism 20 sets the position of the gripper 26 to sx in a direction parallel to the transport track (hereinafter also referred to as “x direction”), and is perpendicular to the transport track in the horizontal plane. The sy is moved in the direction (hereinafter also referred to as “y direction”), and the substrate 60 placed at the transfer target position is gripped. Since the position of the gripping portion 26 is moved, the substrate 60 is gripped on the gripping portion 26 at a position shifted by −sx in the x direction and −sy in the y direction from the reference gripping position. After gripping the substrate 60, the transport mechanism 20 returns the position of the gripper 26 to the original position.
Note that the gripping portion 26 is moved by the operation of any of the base portion 22, the arm portion 24, and the gripping portion 26 of the transport mechanism 20, or a combination of these operations.

  In response to a command from the command unit 114, the transport mechanism 20 moves to the transport start position while holding the substrate 60 at a shifted position, and the substrate cassette that is the transport target so that the grip unit 26 moves along the transport track. Transport again to 50. Since the substrate 60 is gripped at a position shifted by −sx in the x direction and −sy in the y direction from the reference grip position, the substrate 60 is moved in the −sx and y directions in the x direction compared to the case where the substrate 60 is gripped and transported. The trajectory is shifted by -sy.

Each of the sensors 30a and 30b generates a signal when it detects the passage of the front end of the substrate 60. When the receiving unit 102 detects signals from the sensors 30a and 30b, the table creating unit 120 records the signal detection time in association with the gripping position of the substrate 60 with respect to the gripping unit 26 in the reference table 130.
When the substrate 60 reaches the substrate cassette 50 that is the conveyance target, the command unit 114 moves the position of the gripping portion 26 sx in the x direction and sy in the y direction again, and causes the gripping portion 26 to release the substrate 60. 60 is placed at an accurate conveyance target position.

The above processing is repeated for a plurality of shift positions sx and sy, and sensor signal timing is measured in each case and recorded in the reference table 130.
For example, if the sampling interval is Δx in the x direction and Δy in the y direction, i and j are integers satisfying | i | <m and | j | <n, and sx = mΔx and sy = nΔy, (2m−1 ) × (2n−1) different substrate gripping positions, sensor signal timing is recorded in the reference table 130. Here, as the positive numbers m and n indicating the measurement range and the sampling intervals Δx and Δy, values set in advance may be used, and values specified when the user instructs the creation of the reference table 130 or the like. May be used.

4A and 4B show signal timings from the sensor 30 when the transport mechanism 20 grips the substrate 60 at a position shifted in the y direction with respect to the grip portion 26 and transports the substrate 60 to the substrate cassette 50. FIG. Indicates. In this example, the sensor 30a detects the passage of the front edge of the substrate 60 at a time T1 that is earlier than when the substrate 60 is transported at the reference gripping position, and the sensor 30b transports the substrate 60 at the reference gripping position. The passage of the front edge of the substrate 60 is detected at a time T2 that is later than the case.
The table creation unit 120 records the position of the substrate 60 with respect to the gripping unit 26, the signal timing T1 from the sensor 30a, and the signal timing T2 from the sensor 30b in the reference table 130.

FIG. 5A and FIG. 5B are signal timings from the sensor 30 when the transport mechanism 20 grips the substrate 60 at a position shifted in the x direction with respect to the grip portion 26 and transports the substrate 60 to the substrate cassette 50. Indicates. In this case, both the sensor 30a and the sensor 30b detect the passage of the front edge of the substrate 60 at times T3 and T4 that are later than when the sensors 30a and 30b are conveyed at the reference gripping position.
The table creation unit 120 records the position of the substrate 60 with respect to the gripping unit 26, the signal timing T3 from the sensor 30a, and the signal timing T4 from the sensor 30b in the reference table 130.

3B, 4B, and 5B, the sensors 30a and 30b each detect the front end of the substrate 60 when the substrate 60 is transported at the reference gripping position. Although an example in which the times Ta0 and Tb0 are the same time has been shown, Ta0 and Tb0 may not be the same time.
That is, in the present embodiment, the sensors 30a and 30b are not necessarily arranged in the direction perpendicular to the transport track. The installation position of the sensor 30 may be a position where a substrate passing through the transport track can be detected.

  As described above, according to the present embodiment, the installation position of the sensor 30 may not be accurately positioned. Further, the reference table 130 can be created by automatically operating the transport mechanism 20 with the apparatus and the sensor 30 installed at an actual manufacturing site. Therefore, it is possible to simplify the preparation work for detecting the shift of the holding position of the substrate by the sensor.

  In FIGS. 3A to 5B, the time point when the command unit 114 issues a transport start command to the transport mechanism 20 is the time origin T0. However, the time origin may be arbitrarily determined. . For example, the time Ta0 when the sensor 30a detects the front end of the substrate 60 when the substrate 60 is transported at the reference gripping position, and the time Tb0 when the sensor 30b detects the front end of the substrate 60, respectively. It is good also as the origin of the time at the time of expressing a signal timing and the signal timing of the sensor 30b. Further, as will be described later, when one reference table 130 is used for a plurality of tracks, any distance on the track where the distance to the sensor 30 becomes equal within a range in which the plurality of tracks and the reference transport track are parallel to each other. The time at which the gripper 26 passes the point may be defined as the time origin.

FIG. 6 shows an example of the reference table 130.
The reference table 130 associates the position of the substrate 60 with respect to the grip portion 26 and the signal timing from the sensor 30 when the substrate 60 is placed and transported at that position.
For example, when the substrate 60 is gripped and transported with respect to the gripper 26 at a position represented by coordinates (x ₃ , y ₂ ), the receiver 102 sends signals from the sensors 30a and 30b to the time Ta ₃ , Assume that Ta ₂ is acquired. In this case the table creation section 120, _{x 3} field 132 and _{y 2} field 134 and the field intersecting the reference table 130, i.e., in the column corresponding to the substrate position _(x 3, _{y 2),} the sensor 30a, the signal timing from 30b Is recorded (Ta ₃ , Ta ₂ ).

  Here, the origin when the position of the substrate 60 with respect to the grip portion 26 is expressed as coordinates may be arbitrarily determined. For example, the center of the substrate 60 when the substrate 60 is gripped at the reference gripping position may be determined as the origin. In this case, the position coordinates of the substrate 60 with respect to the grip portion 26 represent the deviation of the center of the substrate 60 being gripped from the center of the substrate 60 when the substrate is held at the reference gripping position. This corresponds to the deviation (−sx, −sy) from the gripping position.

The transport mechanism 20 can transport the substrate along a plurality of transport tracks.
FIG. 7 shows an example of a plurality of transport tracks that can be selected when the transport mechanism 20 transports the substrate 60.
The transport mechanism 20 can transport the substrate along three transport paths from the substrate processing apparatus 40a to the substrate cassette 50a, from the substrate processing apparatus 40b to the substrate cassette 50a, and from the substrate processing apparatus 40c to the substrate cassette 50b. When the plurality of tracks are parallel to the reference transfer track in the detectable range of the sensors 30a and 30b, the transfer control device 10 is based on one reference table 130 and the substrate transferred along each track as described later. Can be determined.

Returning to FIG.
When the instruction acquisition unit 100 acquires a transport instruction for the substrate 60 from a user or from a processing control device (not shown) that controls the substrate processing apparatus 40, the instruction acquisition unit 100 causes the trajectory information acquisition unit 106 to transfer the transport path of the substrate 60. Send information acquisition instructions. The trajectory information acquisition unit 106 reads out trajectory information included in the transport instruction or inquires the user to acquire trajectory information, and specifies a trajectory (hereinafter also referred to as “designated transport trajectory”) on which the substrate 60 should be transported. The trajectory information includes at least transfer start position information and transfer target position information.

The command unit 114 of the operation control unit 110 moves the grip unit 26 of the transport mechanism 20 to the substrate processing apparatus 40 that is the transport start position, and grips the substrate 60. At this time, if the position of the substrate 60 processed in the substrate processing apparatus 40 is shifted from the normal position, the gripping portion 26 of the transport mechanism 20 may grip the substrate 60 at a position different from the reference gripping position. is there.
In response to a command from the command unit 114, the transport mechanism 20 transports the substrate 60 toward the transport target position.

The sensors 30a and 30b each generate a signal when detecting the passage of the front end of the substrate 60, and the receiving unit 102 acquires signals from the sensors 30a and 30b. The substrate position acquisition unit 108 searches the reference table 130, and acquires a combination of signal timings close to the combination of signal timings of the sensors 30a and 30b, and a position of the substrate 60 corresponding to the combination with respect to the grip unit 26.
The substrate position acquisition unit 108 uses two or more sets of data close to the measured timing of the sensor 30 to determine the position of the substrate 60 relative to the gripping unit 26 corresponding to the measured values of the signal timings of the sensors 30a and 30b by linear interpolation. Identify. Instead of linear interpolation, quadratic interpolation or polynomial interpolation may be used.
The substrate position acquisition unit 108 calculates the amount of deviation of the substrate 60 from the reference gripping position by taking the difference between the specified position of the substrate 60 relative to the gripping unit 26 and the reference gripping position.

When the reference transport track and the designated transport track are equal, the substrate position acquisition unit 108 can use the position of the substrate 60 relative to the gripping unit 26 shown in the reference table 130 as it is, but when the reference transport track and the specified transport track are different. Requires correction by an offset value.
In this case, the substrate position acquisition unit 108 refers to the attribute information of the reference table 130 and the trajectory information of the designated transport trajectory, and calculates the position coordinate and time offset value based on the positional relationship between the reference transport trajectory and the designated transport trajectory.

For the position coordinates, for example, the distance between the reference transport path and the designated transport path in the vicinity of the detection range of the sensor 30 is set as the position offset value.
For the time, for example, the time offset value is determined so that the time from the time origin to the detection range of the sensors 30a and 30b is equal between the reference transport path and the designated transport path.

  As a result, the same reference table 130 can be used when the substrate is transported on a different track from the reference track used when the reference table 130 is created. The same reference table 130 can also be used when the transport mechanism 20 transports a substrate along a plurality of tracks. Therefore, the preparation work for detecting the shift of the gripping position of the substrate with the sensor can be simplified, and the shift of the gripping position of the substrate can be efficiently identified.

  The correction value calculation unit 112 calculates a correction value for the movement target position of the gripping unit 26 so as to compensate for the positional deviation amount obtained by the substrate position acquisition unit 108. Specifically, for example, when the positional deviation amount is dx in the x direction and dy in the y direction, the movement target position of the gripper 26 is corrected by −dx in the x direction and −dy in the y direction.

The command unit 114 moves the grip unit 26 of the transport mechanism 20 so that it finally reaches the corrected movement target position. Thereby, the shift of the grip position of the substrate 60 is canceled by the movement of the grip portion 26, and the substrate 60 is transported to the original transport target position.
When correcting the movement target position of the grip part 26, the transport mechanism 20 may change any of the operations of the base part 22, the arm part 24, and the grip part 26. Moreover, since it is only necessary to finally reach the corrected movement target position, the trajectory until reaching the movement target position may be arbitrary.
Thereby, the shift | offset | difference of a board | substrate holding position can be compensated comparatively simply in a conveyance process.

The operation according to the above configuration is as follows.
FIG. 8 shows a reference table creation process of the transport control apparatus 10 according to the embodiment.
First, the user inputs a reference table creation instruction, and the instruction acquisition unit 100 acquires the reference table creation instruction (S10). When the user causes the gripper 26 to grip the substrate 60 at the reference gripping position and manually operates the transport mechanism 20 to move the substrate 60 to the transport target position, the trajectory setting unit 116 causes the gripper 26 to The traced path is set as a reference trajectory and recorded as attribute information in the reference table 130 (S12).

  In response to an instruction from the command unit 114, the transport mechanism 20 moves the gripping unit 26 along the reference trajectory, and transports the substrate 60 gripped to the reference gripping position (S14). When the sensor 30 detects the passage of the substrate 60, the sensor 30 emits a signal. When the receiving unit 102 acquires the signal from the sensor 30 (S16), the signal detection time is recorded as attribute information of the reference table 130 (S18). When the substrate 60 reaches the transfer target position, the gripper 26 places the substrate 60 at the transfer target position (S20).

  Since the scanning of the measurement range has not been completed (N in S22), the command unit 114 moves the grip unit 26 of the transport mechanism 20 and grips the substrate 60 at a position shifted from the reference grip position (S24). The transport mechanism 20 returns to the transport start position according to an instruction from the command unit 114, and transports the substrate 60 again so that the gripper 26 moves along the reference track (S14). When the sensor 30 detects the passage of the substrate 60, the sensor 30 generates a signal. When the receiving unit 102 acquires the signal from the sensor 30 (S16), the position of the substrate 60 with respect to the gripping unit 26 and the signal detection time are associated with each other. 130 (S18). When the substrate 60 reaches the transfer target position, the gripper 26 places the substrate 60 at the original transfer target position (S20).

  The processing of step 24 and steps S14 to S22 is repeated while changing the substrate gripping position in units of sampling intervals, and when the scanning of the measurement range is completed (Y in S22), the creation process of the reference table 130 is finished.

Even after the reference table 130 is created once and the substrate transfer processing is started regularly using the reference table 130, the reference table 130 is created again once a month or several times a year, for example.
As a result, it is possible to reflect the positional shift and dimensional change of the substrate processing apparatus 40, the substrate cassette 50, the transport mechanism 20 and the sensor 30 due to secular change on the reference table 130, and more accurately transport over a long period of time. It is possible to specify the displacement of the substrate holding position inside.

FIG. 9 shows a substrate gripping position calibration process of the transport control apparatus 10 according to the embodiment.
When the instruction acquisition unit 100 acquires the transport instruction for the substrate 60 (S30), the trajectory information acquisition unit 106 acquires information on the designated transport trajectory for actually transporting the substrate (S32). The command unit 114 causes the transport mechanism 20 to transport the substrate 60 toward the transport target position on the designated transport path (S34). When the sensor 30 detects the passage of the front end of the substrate 60, the sensor 30 generates a signal, and the receiving unit 102 acquires the signal from the sensor 30 (S36).

  The substrate position acquisition unit 108 searches the reference table 130, acquires two or more data close to the combination of the detected signal timings, obtains the holding position of the substrate 60 with respect to the holding unit 26 by interpolation, and obtains the reference holding position. The amount of displacement of the gripping position is specified (S38). The correction value calculation unit 112 corrects the movement target position of the gripping unit 26 based on the shift amount of the gripping position (S40), and the transport mechanism 20 determines the movement target position of the gripping unit 26 based on the calculated correction value. The correction is made to compensate for the shift of the holding position of the substrate, and the substrate 60 is transferred to the original transfer target position (S42).

  In the above, this invention was demonstrated based on embodiment. It will be understood by those skilled in the art that the present invention is not limited to the above-described embodiment, and various design changes are possible, various modifications are possible, and such modifications are within the scope of the present invention.

  In the embodiment, the substrate is detected by the two sensors 30, but one sensor 30 may be used. In this case, the sensor 30 generates a signal when the substrate non-detection state is switched to the substrate detection state. That is, a signal is generated when the trailing edge passes in addition to when the leading edge of the substrate 60 passes. As in the embodiment, the combination of the signal timing from the sensor 30a and the signal timing from the sensor 30b in the embodiment is replaced with a combination of the signal timing at the time of passing through the leading edge and the signal timing at the time of passing through the trailing edge. Furthermore, the deviation of the substrate gripping position can be specified by simple preparation. Furthermore, it can cope with a case where the sensor installation space is limited.

Three or more sensors may be provided. When two or more sensors are provided, some or all of the sensors may detect passage of both the front edge and the rear edge of the substrate 60. In this case, the reference table 130 associates the holding position of the substrate with respect to the holding unit 26 and the substrate detection timing of each sensor 30.
Thereby, the shift | offset | difference of the holding position of the board | substrate 60 can be pinpointed with high precision. In addition, the present invention can be applied to a positional deviation when transporting a transport target having a shape other than a circle.

In the embodiment, the example of the transport mechanism for transporting the substrate 60 has been described. However, the present invention is not limited to this, and the transport object having a specific shape is held or placed and the transport is repeated in the same transport sequence. Applicable to processing and equipment.
By referring to the signal timing and the table according to the known shape of the substrate, it is possible to calculate not only the deviation amount but also the coordinates of the substrate.

  As described above, the present invention can be used in a transfer control device that controls transfer of a substrate.

  DESCRIPTION OF SYMBOLS 10 Conveyance control apparatus, 20 Conveyance mechanism, 26 Gripping part, 30 Sensor, 60 Substrate, 70 Conveyance control system, 80, 82, 84 Conveyance track, 102 Receiving part, 104 Storage part, 108 Substrate position acquisition part, 110 Operation control part 130 Reference table.

Claims (6)

A transport control device for controlling a transport mechanism for transporting a substrate,
A receiving unit for obtaining a signal indicating the passage timing of the substrate in the middle of the substrate transport orbit by the transport mechanism;
A storage unit for storing a reference table used for specifying a positional deviation amount when the substrate gripping unit of the transport mechanism grips the substrate;
A substrate position acquisition unit that refers to the reference table based on the timing of the signal acquired by the reception unit and identifies the amount of substrate displacement;
The reference table associates a plurality of known positions of the substrate with respect to the substrate gripping unit and timings of signals acquired by the receiving unit when the substrate is gripped and transported at each position. Transport control device.   The apparatus according to claim 1, further comprising an operation control unit that corrects the operation of the transport mechanism based on the substrate positional deviation amount specified by the substrate position acquisition unit and transports the substrate to a transport target position. The conveyance control apparatus as described. The transport mechanism is capable of transporting a substrate along a plurality of transport tracks,
The substrate position acquisition unit refers to the reference table based on one designated transfer trajectory of the plurality of transfer trajectories and the timing of the signal acquired by the receiving unit, and determines the amount of substrate positional deviation. The conveyance control device according to claim 1, wherein the conveyance control device is specified. A transport system comprising a transport mechanism that transports a substrate, a sensor that emits a signal when the passage of the substrate is detected, and a transport control device that controls the transport mechanism,
The transfer control device
A storage unit for storing a reference table used for specifying a positional deviation amount when the substrate gripping unit of the transport mechanism grips the substrate;
A substrate position acquisition unit that refers to the reference table based on the timing of a signal generated by the sensor and specifies the amount of substrate displacement;
The reference table associates a plurality of positions of the substrate with respect to the substrate gripping unit and timings of signals generated by the sensor when the substrate is gripped and transported at each position,
The transport system corrects the transport operation based on the positional deviation amount of the substrate specified by the substrate position acquisition unit, and transports the substrate to a transport target position. In a transport control system comprising a transport mechanism for transporting a substrate, a sensor for detecting the passage of the substrate, and a transport control device, a method for creating a reference table used for specifying a positional deviation amount of a substrate,
The transfer control device storing a transfer start position of the transfer mechanism and a transfer target position;
Gripping the substrate placed at the transport start position by shifting the substrate by a known shift amount;
A transport mechanism that grips the substrate transports the substrate toward the transport target position;
The transfer control device acquiring a signal that is emitted when the sensor detects passage of a substrate;
The conveyance control device storing the timing of the acquired signal and the known deviation amount in association with each other;
A method for creating a reference table, comprising: A method for calibrating a positional deviation of a substrate held by the transport mechanism with reference to a reference table created by the method according to claim 5,
The transport control device acquiring a signal generated by the sensor while the transport mechanism transports the substrate;
The transfer control device refers to the reference table based on the timing of the acquired signal, and specifies the amount of substrate displacement,
The transport mechanism correcting the transport operation based on the positional deviation amount of the substrate and transporting the substrate to a transport target position;
A gripping position calibration method comprising:

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