Control Device for Substrate Transfer Robot and Control Method for Joint Motor

Abstract

To stably and highly accurate elimination of board misalignment.SOLUTION: A control device controls a board transfer robot whose joint axes are oriented in the vertical direction. The rotation direction of a joint motor that drives the joint can be switched. The control device corrects the position of a hand at least in either a case of taking out the board or a case of placing the board on the basis of position deviation information. The control device controls the hand to pass through the relay position before the hand reaches the correction position, which is the position of the hand after correction. In the control device, the joint motor drives the joint in one direction to cause the hand to reach the relay position, and the joint motor drives the joint in the same one direction to cause the hand to reach from the relay position to the correction position.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to control of a motor that drives a joint in a substrate transfer robot whose joint has an axis in the vertical direction.

Background Art

[0002] Conventionally, in a substrate transfer system, when a positional deviation occurs in a substrate to be transferred, a configuration is known in which the positional deviation is eliminated by changing the position of a hand when taking out or placing the substrate.

[0003] Patent Document 1 discloses a wafer transfer system having a pre-aligner device. In Patent Document 1, it is mentioned that the pre-aligner device not only aligns the notch position of the wafer but also detects, calculates the amount of center deviation, and performs center alignment. In Patent Document 1, as a method of performing center alignment, based on the information on the amount of center deviation, the wafer transfer device shifts (corrects) the wafer receiving position with respect to the turning center of the pre-aligner device, and moves the end effector of the transfer device so that the center position coincides when receiving the wafer. This method is exemplified.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the configuration of Patent Document 1, the wafer receiving position can vary depending on the amount of center deviation. Usually, a speed reducer or the like is arranged between the joint motor and the joint of the robot. A gear transmission mechanism is often used in the speed reducer. When the rotation direction of the joint changes during the movement of the hand, the positional accuracy decreases due to the backlash of the gear train, and there are cases where the center deviation cannot be accurately corrected.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to stably eliminate positional deviation with high accuracy regardless of how the positional deviation of the substrate occurs.

Means for Solving the Problems

[0007] The problems to be solved by the present invention are as described above. Next, the means for solving these problems and their effects will be described.

[0008] According to a first aspect of the present invention, there is provided a control device for a substrate transfer robot having the following configuration. That is, this control device controls a substrate transfer robot including a hand, a joint, and a joint motor. The hand can hold a substrate. The axis of the joint is oriented in the vertical direction. The joint motor drives the joint. The joint motor can switch the rotation direction. The control device corrects the position of the hand in at least one of the cases of taking out and placing the substrate based on position deviation information indicating the position deviation of the substrate. Before the hand reaches the corrected position, which is the position of the hand after correction, the control device controls the hand to pass through a relay position. The control device causes the joint motor to drive the joint in one direction so that the hand reaches the relay position, and causes the joint motor to the one direction and drive the joint only in the same one direction so that the hand reaches the corrected position from the relay position. The relay position is spaced apart from the range within which the correction position can be taken. The relay position is determined such that the one direction is the same regardless of the correction position.

[0009] Thereby, the adverse effects due to the backlash of the joint drive portion can be stably avoided. Therefore, the positional accuracy when taking out / placing the substrate is improved. Since the movement distance from the relay position to the extraction position can be ensured, the axis alignment accuracy can be improved. With simple control, the adverse effects caused by backlash can be avoided.

[0010] According to a second aspect of the present invention, there is provided a robot system including the above control device and a substrate transfer robot.

[0011] Thereby, a robot system capable of stably improving the positional accuracy of the substrate can be obtained.

[0012] According to a third aspect of the present invention, a method for controlling an articulation motor is provided. That is, this method for controlling an articulation motor controls the articulation motor in a substrate transfer robot including a hand, an articulation, and the articulation motor. The hand can hold a substrate. The axis of the articulation is oriented in the vertical direction. The articulation motor drives the articulation. The articulation motor can switch the rotation direction. In this control method, based on position deviation information indicating the position deviation of the substrate, the position of the hand is corrected at least in either the case of taking out the substrate or the case of placing the substrate. In this control method, before the hand reaches the corrected position which is the position of the hand after correction, the hand is controlled to pass through an intermediate position. In this control method, the articulation motor drives the articulation in one direction so that the hand reaches the intermediate position, and the articulation motor the one direction and drives the articulation only in the same one direction so that the hand reaches the corrected position from the intermediate position. The relay position is spaced apart from the range within which the correction position can be taken. The relay position is determined such that the one direction is the same regardless of the correction position.

[0013] Thereby, the adverse effect due to the backlash of the articulation drive portion can be stably avoided. Therefore, the position accuracy in the case of taking out / placing the substrate is improved. Since the movement distance from the relay position to the extraction position can be ensured, the axis alignment accuracy can be improved. With simple control, the adverse effects caused by backlash can be avoided.

Effects of the Invention

[0014] According to the present invention, regardless of how the position deviation of the substrate occurs, the position deviation can be stably eliminated with high accuracy.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0016] Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the configuration of a robot system 100 according to an embodiment of the present invention. FIG. 2 is a perspective view showing the configuration of the robot 1. FIG. 3 is a block diagram showing a part of the configuration of the robot system 100.

[0017] The robot system 100 shown in FIG. 1 is a system for causing the robot 1 to perform work in a work space such as a clean room.

[0018] The robot system 100 includes a robot 1, a position deviation detection device (substrate aligner) 4, and a controller (control device) 5.

[0019] The robot 1 functions, for example, as a wafer transfer robot that transfers the wafer 2 stored in the storage container 6. In the present embodiment, the robot 1 is realized by a SCARA (Selective Compliance Assembly Robot Arm) type horizontal articulated robot. SCARA is an abbreviation for Selective Compliance Assembly Robot Arm.

[0020] The wafer 2 transported by the robot 1 is a type of substrate. The wafer 2 is formed in a circular thin plate shape.

[0021] As shown in FIG. 2, the robot 1 includes a hand (holding part) 10, a manipulator 11, and joint motors 12a, 12b, and 12c.

[0022] The hand 10 is a type of end effector, and is generally formed in a V shape or a U shape in a plan view. The hand 10 is supported at the tip of the manipulator 11 (specifically, the second link 16 described later). The hand 10 rotates with respect to the second link 16 about a third axis c3 extending in the vertical direction.

[0023] The manipulator 11 mainly includes a base 13, a lifting axis 14, a first link 15, and a second link 16.

[0024] The base 13 is fixed to the ground (for example, the floor surface of a clean room). The base 13 functions as a base member that supports the lifting axis 14.

[0025] The lifting axis 14 moves in the vertical direction with respect to the base 13. By this lifting, the heights of the first link 15, the second link 16, and the hand 10 can be changed.

[0026] The first link 15 is supported above the lifting axis 14. The first link 15 rotates with respect to the lifting axis 14 about a first axis c1 extending in the vertical direction. Thereby, the posture of the first link 15 can be changed within a horizontal plane.

[0027] The second link 16 is supported at the tip of the first link 15. The second link 16 rotates with respect to the first link 15 about a second axis c2 extending in the vertical direction. Thereby, the posture of the second link 16 can be changed within a horizontal plane.

[0028] Thus, the manipulator 11 is configured to include three joints whose axes face in the vertical direction. Hereinafter, in order to specify each joint, it may be called by attaching the symbols c1, c2, and c3 of the central axis.

[0029] The joint motors 12a, 12b, and 12c drive the joints c1, c2, and c3 respectively. Thereby, the position and orientation of the hand 10 in a plan view can be changed in various ways. The joint motors 12a, 12b, and 12c are configured as servo motors, which are a type of electric motor.

[0030] The joint motor 12a that drives the joint c1 is arranged on the first link 15. The joint motor 12b that drives the joint c2 is arranged on the first link 15. The joint motor 12c that drives the joint c3 is arranged on the second link 16. However, the layout of each motor is not limited to the above.

[0031] The position deviation detection device 4 is composed of, for example, a pre-aligner (wafer aligner). As shown in FIG. 1, the position deviation detection device 4 includes a turntable 41 and a line sensor 42.

[0032] The turntable 41 can rotate the wafer 2 by an electric motor or the like (not shown). The turntable 41 rotates with the wafer 2 placed thereon. The turntable 41 is formed in a cylindrical shape as shown in FIG. 1, for example. However, it is not limited to this.

[0033] The line sensor 42 is composed of, for example, a transmissive sensor having a light projecting part and a light receiving part. The light projecting part and the light receiving part face each other and are arranged at a predetermined interval in the vertical direction. The line sensor 42 projects detection light through the light projecting parts arranged in the radial direction of the turntable 41, and receives the detection light through the light receiving part provided below the light projecting part. The detection light can be, for example, laser light. When the wafer 2 is placed on the turntable 41, its outer edge is located between the light projecting part and the light receiving part.

[0034] The line sensor 42 is electrically connected to a deviation amount acquisition unit 51 described later. The line sensor 42 transmits the detection result of the light receiving unit to the deviation amount acquisition unit 51. Although details will be described later, the change in the detection result of the light receiving unit when the turntable 41 is rotated corresponds to the shape of the outer edge of the wafer 2. From this shape of the outer edge, the positional deviation of the center of the wafer 2 from the rotation center of the turntable 41 can be detected. Therefore, in the positional deviation detection device 4, the detection reference position for the positional deviation is the rotation center of the turntable 41. The deviation amount acquisition unit 51 acquires the deviation amount of the wafer 2 based on the detection result of the light receiving unit.

[0035] The line sensor 42 is not limited to a transmissive sensor, and may be composed of, for example, a reflective sensor.

[0036] As shown in FIG. 3, the controller 5 includes a deviation amount acquisition unit 51 and a control unit 52. The controller 5 is configured as a known computer including a CPU, ROM, RAM, auxiliary storage device, etc. The auxiliary storage device is configured as, for example, an HDD, SSD, etc. The auxiliary storage device stores a robot control program and the like for realizing the control method of the articulated motors 12a, 12b, 12c of the present invention. By the cooperation of these hardware and software, the controller 5 can be operated as the deviation amount acquisition unit 51, the control unit 52, etc.

[0037] As described above, the deviation amount acquisition unit 51 acquires the deviation amount of the wafer 2 based on the detection result from the line sensor 42.

[0038] The control unit 52 outputs command values to the respective drive motors that drive the respective parts of the above-described robot 1 according to a predetermined operation program or a movement command input from the user, etc., and controls them to move the hand 10 to a predetermined command position. The drive motors include, in addition to a schematic electric motor for vertically displacing the elevating shaft 14, the above-described articulated motors 12a, 12b, 12c.

[0039] Next, a method for acquiring the positional deviation of the wafer 2 using the positional deviation detection device 4 will be described in detail.

[0040] The control unit 52 controls the robot 1 to take out the wafer 2 from the storage container 6 and convey it to the turntable 41 of the position deviation detection device 4. After the wafer 2 is placed on the turntable 41, the control unit 52 controls the robot 1 to standby at a predetermined position slightly retracted from the position deviation detection device 4. This position can be referred to as a relay position through which the hand 10 passes after the wafer 2 is placed on the turntable 41 and before the wafer 2 is taken out from the turntable 41. Details of this relay position will be described later.

[0041] When the wafer 2 is placed on the turntable 41, the position deviation detection device 4 rotates the turntable 41 while continuously detecting the peripheral position of the wafer 2 with the line sensor 42. When the central axis 2c of the wafer 2 completely coincides with the rotation center of the turntable 41, the peripheral position of the wafer 2 detected by the line sensor 42 is constant regardless of the rotation phase of the turntable 41. When the center of the wafer 2 is deviated from the rotation center of the turntable 41, the peripheral position of the wafer 2 changes with an amplitude corresponding to the deviation distance in conjunction with the rotation of the turntable 41. Also, the direction of the deviation can be obtained based on, for example, the phase of the turntable 41 at which the peripheral position becomes maximum or minimum.

[0042] The deviation amount acquisition unit 51 acquires the deviation amount based on the detection result of the line sensor 42. The deviation amount indicates in which direction and by what distance the central axis 2c of the wafer 2 shown in FIG. 1 is deviated from the rotation center of the turntable 41. The deviation amount can be represented by, for example, a planar vector (ox, oy). Since the calculation method is well-known, the details are omitted, but this deviation amount can be obtained by performing geometric calculations. The deviation amount acquisition unit 51 outputs the obtained deviation amount to the control unit 52.

[0043] The original position where the hand 10 takes out the wafer 2 is a position where its center coincides with the rotation center of the turntable 41. However, if the hand 10 takes out the wafer 2 at this position and there is a displacement of the wafer 2 as described above, then this displacement will directly become the displacement of the wafer 2 with respect to the hand 10. Therefore, the control unit 52 corrects the position where the hand 10 takes out the wafer 2 based on the displacement amount input from the displacement amount acquisition unit 51. The displacement amount is information (position displacement information) indicating the position displacement of the wafer 2. The correction can be achieved by shifting the hand 10 from its original position in the same manner as the obtained displacement amount of the wafer 2. Hereinafter, the corrected position may be referred to as the take-out position (corrected position).

[0044] The control unit 52 moves the hand 10 from the aforementioned relay position to the take-out position. When the movement is completed, the hand 10 takes out the wafer 2 from the turntable 41. Thereby, the wafer 2 can be held by the hand 10 with the central axis 2c of the wafer 2 coinciding with the center of the hand 10. The control unit 52 controls the robot 1 to convey the wafer 2 held by the hand 10 to an appropriate conveyance destination.

[0045] Next, the relay position of the hand 10 when the position displacement detection device 4 is detecting the position displacement will be described in detail.

[0046] While the position displacement detection device 4 is detecting the position displacement of the wafer 2, the hand 10 waits at a location where it does not interfere with the detection of the position displacement. The position (relay position) where the hand 10 waits is determined to be common regardless of the displacement amount of the wafer 2. Thereby, the control of the robot 1 can be simplified. It is preferable that the hand 10 waits near the turntable 41 because the wafer 2 can be taken out immediately.

[0047] When the hand 10 is waiting at the relay position, the amount of deviation of the wafer 2 is unknown. However, if the amount of deviation of the wafer 2 exceeds a predetermined range, the position deviation detection device 4 cannot detect the amount of deviation, or the detected value becomes an abnormal value, so that the robot system 100 stops abnormally. Therefore, the position where the hand 10 picks up the wafer 2 from the position deviation detection device 4 actually falls within a range of a predetermined size.

[0048] When the amount of deviation of the wafer 2 is detected by the position deviation detection device 4, the actual position of the hand 10 when picking up the wafer 2 from the position deviation detection device 4 is determined. This position is the aforementioned pick-up position. The hand 10 moves from the relay position to the pick-up position by rotating one or more of the three joint motors 12a, 12b, 12c in an appropriate direction.

[0049] The relay position can basically be set arbitrarily. Generally, it is preferable that the moving distance from the relay position to the pick-up position is short. Considering this point of view, as shown in the comparative example of FIG. 4, it is considered preferable to set the relay position of the hand 10 at a central or average position so that the moving distance is relatively short regardless of the pick-up position.

[0050] However, when the relay position is set in this way, depending on the direction in which the deviation of the wafer 2 occurs from the rotation center of the turntable 41, the rotation directions of the joints c1, c2, c3 for moving the hand 10 from the relay position to the pick-up position change. This means that the rotation directions of the respective joint motors 12a, 12b, 12c are not constant, and the rotation direction becomes reverse depending on the case, for example, in the plus direction at one pick-up position and in the minus direction at another pick-up position.

[0051] In this specification, the plus direction means the clockwise direction with respect to the joint, and the minus direction means the counterclockwise direction. However, the definitions of the plus direction and the minus direction are for convenience.

[0052] A gear transmission mechanism (for example, a reduction gear) is disposed between each of the joint motors 12a, 12b, 12c and the corresponding joints c1, c2, c3. When the rotation direction is switched in any of the three joint motors 12a, 12b, 12c, the positional accuracy of the hand 10 deteriorates due to the influence of the backlash of the gear transmission mechanism. As a result, the deviation of the wafer 2 obtained by the position deviation detection device 4 cannot be stably canceled with high precision.

[0053] Therefore, in the present embodiment, as shown in FIG. 5, the relay position of the hand 10 is set to a position sufficiently biased to one side with respect to the range in which the take-out position can be taken. Therefore, no matter what position the take-out position is within the predetermined range, the rotation direction of each of the three joints c1, c2, c3 from the relay position to the take-out position of the hand 10 is not affected.

[0054] The relay position is determined so as to be outside the range in which the take-out position can be taken. Strictly speaking, in the present embodiment, the angle of the joint corresponding to the relay position of the hand 10 does not fall within the angle range of the joint corresponding to the range of the take-out position, and deviates from either side of the angle range. This relationship holds for all of the three joints c1, c2, c3 of the manipulator 11. An example of the relationship between the range of the take-out position and the relay position in the three joints c1, c2, c3 is shown as a conceptual diagram in FIG. Focusing on the joint c3 in FIG. 6, no matter what position the take-out position is within the predetermined range, the joint c3 is always driven only in the negative direction until the hand 10 reaches the take-out position from the relay position.

[0055] Furthermore, when the hand 10 reaches the relay position, the control unit 52 controls the joints c1, c2, and c3 to be driven in the same direction as when the hand 10 moves from the relay position to the picking position. This driving direction is shown as a white arrow in FIG. 6. Focusing on the joint c3, when the joint c3 is driven in the negative direction, the hand 10 reaches the relay position. The negative direction, which is the driving direction at this time, coincides with the direction in which the joint c3 is driven until the hand 10 moves from the relay position to the picking position. This relationship holds for each of the three joints c1, c2, and c3 of the manipulator 11.

[0056] By the above control, no matter what position the picking position is, the hand 10 is not affected by backlash when reaching the picking position. Therefore, the accuracy of the picking position of the hand 10 can be stably improved.

[0057] When the relay position is separated from the range of the picking position to a certain extent, the moving distance from the relay position to the picking position can be ensured. When moving the hand 10 from the relay position to the picking position, if the angle change of any of the joints c1, c2, and c3 is almost zero, the coincidence accuracy between the actual angle and the target angle decreases due to the influence of backlash for the relevant joint. In this embodiment, the relay position is determined so that the angle of any of the joints c1, c2, and c3 changes to some extent until the hand 10 moves from the relay position to the picking position, no matter what position the picking position is within a predetermined range. Thereby, the coincidence accuracy of the axes of each joint can be maintained well, and a decrease in the position accuracy of the hand 10 at the picking position can be prevented.

[0058] As described above, the controller 5 controls the robot 1 including the hand 10, the joints c1, c2, c3, and the joint motors 12a, 12b, 12c. The hand 10 can hold the wafer 2. The axes of the joints c1, c2, c3 are oriented in the vertical direction. The joint motors 12a, 12b, 12c drive the joints c1, c2, c3. Each of the joint motors 12a, 12b, 12c can switch the rotation direction. The controller 5 corrects the position of the hand 10 when taking out the wafer 2 based on the position deviation information indicating the position deviation of the wafer 2. Before the hand 10 reaches the take-out position, which is the position of the hand 10 after correction, the controller 5 controls the hand 10 to pass through the relay position. The controller 5 controls the joint motor 12c to drive the joint c3 in one direction so that the hand 10 reaches the relay position, and controls the joint motor 12c to drive the joint c3 only in the same one direction so that the hand 10 reaches the take-out position from the relay position. The controller 5 controls the other joint motors 12a, 12b in the same manner.

[0059] Thereby, it is possible to stably avoid the adverse effects of backlash on the correction of the position of the hand 10. Thereby, a robot 1 with excellent position accuracy can be obtained.

[0060] Further, in the controller 5 of the substrate transfer robot of the present embodiment, the relay position is separated from the range where the correction position can be taken.

[0061] Thereby, since the movement distance from the relay position to the take-out position can be ensured, the axis alignment accuracy can be improved.

[0062] Further, in the controller 5 of the substrate transfer robot of the present embodiment, one direction is the same regardless of the correction position.

[0063] Thereby, the adverse effects of backlash can be avoided with simple control.

[0064] In addition, in the present embodiment, the amount of deviation is information measured by the position deviation detection device 4 on the position deviation of the wafer 2 set in the position deviation detection device 4. The controller 5 corrects the position of the hand 10 when taking out the wafer 2 set in the position deviation detection device 4 based on the amount of deviation.

[0065] Thereby, immediately after the position deviation of the wafer 2 is measured, the wafer 2 can be taken out from the position deviation detection device 4 so as to cancel the position deviation.

[0066] In addition, the controller 5 of the present embodiment controls the robot 1 so that the hand 10 waits at the relay position after setting the wafer 2 in the position deviation detection device 4 and before taking out the wafer 2 from the position deviation detection device 4.

[0067] Thereby, a series of operations from setting the wafer 2 in the position deviation detection device 4 to taking out the wafer 2 can be performed smoothly.

[0068] Although the preferred embodiments of the present invention have been described above, the above configuration can be modified as follows, for example.

[0069] The control described in the above embodiment can also be applied when taking out the wafer 2 from outside the position deviation detection device 4 (for example, a stage for placing the wafer 2). The amount of deviation of the wafer 2 on the stage can be obtained, for example, by analyzing an image of the wafer 2 taken with a camera (not shown).

[0070] The correction of the position of the hand 10 can be applied not only when taking out the wafer 2 from the position deviation detection device 4, but also, for example, when placing the wafer 2 held by the hand 10 in the storage container 6. The amount of deviation of the wafer 2 with respect to the hand 10 can be obtained, for example, by analyzing an image of the wafer 2 held by the hand 10 taken with a camera (not shown). In order to obtain the amount of deviation of the wafer 2 with respect to the hand 10, a non-contact sensor can be provided at an appropriate position of the robot system 100. For example, two optical sensors are arranged at a position where the wafer 2 can cross. The optical axes of the optical sensors are perpendicular to the horizontal surface of the wafer 2. In order to acquire the amount of deviation of the wafer 2, the controller 5 horizontally moves the hand 10 along a predetermined path while holding the wafer 2. During this movement, the coordinates of the hand 10 are stored when the wafer 2 blocks the optical path of each optical sensor and when the blocking is released. A virtual circle is calculated based on the stored coordinates, and based on the position of the center of this virtual circle, the amount of deviation of the wafer 2 with respect to the hand 10 is calculated. Based on the amount of deviation, the position where the robot 1 places the wafer 2 in the storage container 6 is corrected.

[0071] When the robot 1 places the wafer 2 in the storage container 6 at the corrected position, by performing the same control as in the above embodiment, the adverse effect of backlash on the position accuracy can be stably avoided. In this case, the position where the hand 10 waits can be referred to as a relay position that the hand 10 passes through before reaching the position where the wafer 2 is placed in the storage container 6 (the corrected position). When the robot 1 places the wafer 2 in a location other than the storage container 6 (for example, a semiconductor processing apparatus), the above control can also be applied.

[0072] While the position deviation detection device 4 is detecting the position deviation of the wafer 2, the hand 10 may perform other operations (for example, the transfer operation of another wafer 2) without waiting at the relay position. If the detection of the position deviation by the position deviation detection device 4 is completed during other operations, the hand 10 that has finished the operation may pass through without stopping at the relay position and reach the take-out position.

[0073] The control of the turntable 41, the line sensor 42, etc. included in the position deviation detection device 4 may be performed by the controller 5 of the robot 1, or may be performed by another computer. In other words, the deviation amount may be calculated and acquired by the controller 5 itself, or may be input to the controller 5 from the outside.

[0074] The number of joints of the manipulator 11 having an axis in the vertical direction is not limited to three, and may be one, two, or four or more. The hand 10 of the manipulator 11 may be configured to be reversible about a horizontal flip axis.

[0075] The method by which the hand 10 holds the wafer 2 is arbitrary, and various methods such as a passive grip, a suction grip, and an edge grip can be adopted.

[0076] The control described in the above embodiment can also be applied when the robot 1 transports a substrate other than the wafer 2.

Explanation of Reference Numerals

[0077] 1 Robot (Substrate Transfer Robot) 2 Wafer (Substrate) 4 Position Deviation Detection Device (Substrate Aligner) 5 Controller (Control Device) 10 Hand 12a, 12b, 12c Joint Motors 100 Robot System c1, c2, c3 Joints

Claims

1. a hand capable of holding a substrate, a joint with an axis oriented in the vertical direction, a joint motor capable of switching the rotation direction for driving the joint, In a control device for controlling a substrate transfer robot including: Based on position deviation information indicating the position deviation of the substrate, correct the position of the hand in at least one of the cases of taking out and placing the substrate, Before the hand reaches the corrected position, which is the position of the hand after correction, control the hand to pass through an intermediate position, The joint motor drives the joint in one direction so that the hand reaches the intermediate position, and the joint motor drives the joint only in the same one direction as the one direction so that the hand reaches the corrected position from the intermediate position, The intermediate position is spaced apart from the range where the corrected position can be taken, The intermediate position is determined such that the one direction is the same regardless of the state of the corrected position. A control device for a substrate transfer robot.

2. A control device for a substrate transfer robot according to claim 1, The position deviation information is information measured by the substrate aligner on the position deviation of the substrate set in the substrate aligner, A control device for a substrate transfer robot, characterized in that based on the position deviation information, correct the position of the hand when taking out the substrate set in the substrate aligner.

3. A control device for a substrate transfer robot according to claim 2, After setting the substrate on the substrate aligner and before taking out the substrate from the substrate aligner, control the substrate transfer robot so that the hand waits at the intermediate position. A control device for a substrate transfer robot.

4. A control device for a substrate transfer robot according to claim 1, A control device for a substrate transfer robot, characterized in that based on the position deviation information, correct the position of the hand when placing the substrate in a storage container.

5. A control device for a substrate transfer robot according to claim 4, The position deviation information is characterized in that it is acquired while the substrate is held by the hand. A control device for a substrate transfer robot.

6. A control device for a substrate transfer robot according to any one of claims 1 to 5, The substrate transfer robot, A robot system characterized by comprising.

7. a hand capable of holding a substrate, a joint with an axis oriented in the vertical direction, A joint motor capable of switching the rotation direction for driving the joint, In a control method of a joint motor in a substrate transfer robot including, Based on the position deviation information indicating the position deviation of the substrate, correct the position of the hand in at least one of the cases of taking out and placing the substrate, Before the hand reaches the corrected position, which is the position of the hand after correction, control the hand to pass through an intermediate position, The joint motor drives the joint in one direction so that the hand reaches the intermediate position, and the joint motor drives the joint only in the same one direction as the one direction so that the hand reaches the corrected position from the intermediate position, The intermediate position is separated from the range where the corrected position can be taken, The control method of the joint motor is characterized in that the intermediate position is determined so that the one direction is the same regardless of the corrected position.

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