TWI876761B - Conveying device and control method of conveying device - Google Patents

Abstract

The transport robot (1A) comprises: an end actuator (20) having a plurality of chuck parts (21), wherein the plurality of chuck parts (21) are arranged in an up-down direction and respectively chuck wafers; at least two photoelectric sensors (31) are arranged at a spacing (P2) less than half of the distance (D1) from the topmost chuck part (21) to the bottommost chuck part (21) of the plurality of chuck parts (21), and detect whether there are objects on the sides of the plurality of chuck parts (21); a position data storage unit; a control unit; and a calculation unit.

Description

Conveying device and control method of conveying device

The present invention relates to a conveying device and a control method of the conveying device.

In the past, there is a known conveying device that includes a plurality of chucks for conveying a plurality of substrates in batches. In such a conveying device, there is a device that measures the height of the chuck or substrate in order to clamp the substrate without damaging the substrate using the chuck.

For example, Patent Document 1 discloses a transport device, which includes: a base disposed between the transport device body and a cassette containing substrates and lifted and lowered by a lifting mechanism; a sensor disposed on the base and measuring the height of each of a plurality of substrates in the cassette by lifting and lowering the base; and an actuator that adjusts the height of the chuck head based on the height of the substrate measured by the sensor.

In addition, Patent Document 2 discloses a transport device, which includes: a plurality of clamping heads each having a lifting pad and using the lifting pad to clamp a substrate; and a lifting mechanism for lifting a sensor, which detects the substrate contained in the cassette. The transport device described in Patent Document 2 uses a lifting mechanism to lift the sensor, thereby not only detecting the substrate, but also detecting whether the lifting pad is in the desired lifting state.

[Prior Art Literature]

[Patent Literature]

[Patent document 1] Japanese Patent Publication No. 2004-22807

[Patent Document 2] Japanese Patent Publication No. 2017-224658

In the transport device described in Patent Document 1, the lifting mechanism lifts the base, thereby lifting the sensor. Therefore, in order to measure the height of all the multiple substrates in the cassette, it is necessary to lift the sensor by a distance from the bottom of the cassette to the top plate. As a result, the lifting distance of the sensor becomes larger, causing the measurement to take time.

In addition, in the conveying device described in Patent Document 2, in order to detect the lifting status of the lifting pads of all the chuck parts and the presence or absence of the substrate, it is also necessary to lift the sensor by a distance equivalent to: from the lowest chuck part below the substrate at the bottom layer of the chuck to the top of the substrate at the top layer of the chuck when the chuck part enters the cassette. As a result, the lifting distance of the sensor becomes larger, causing the measurement to take time.

This invention is designed to solve this problem. Its purpose is to provide a conveying device and a control method for the conveying device, which can detect whether the height of each clamping head for clamping the substrate is abnormal in a short time.

In order to achieve the above-mentioned purpose, the conveying device of the first aspect of the present invention is characterized by comprising: an end actuator having a plurality of clamping heads arranged in the vertical direction and clamping the substrates respectively; at least two first sensors arranged at a distance less than half of the distance from the topmost clamping head located at the top to the bottommost clamping head located at the bottom of the plurality of clamping heads, and detecting whether there is an object on the side of the plurality of clamping heads; position data A storage unit stores a database, wherein the database stores data of normal vertical positions of the plurality of chuck units; a control unit causes the end actuator to rise relative to the at least two first sensors by at least the distance when the lowest chuck unit is at a first reference position, wherein the first reference position is lower than the lowest first sensor of the at least two first sensors by the distance, or when the highest chuck unit is at a first reference position. The end effector is caused to descend relative to the at least two first sensors by at least the distance in a state of the second reference position, the second reference position being higher than the first sensor located at the top of the at least two first sensors by the distance; and the calculation unit obtains from the control unit the relative movement of the end effector from the first reference position or the second reference position during the period of ascending or descending the end effector relative to the at least two first sensors. The moving distance data is obtained, and the detection data is obtained from the at least two first sensors. Based on the obtained moving distance data and the detection data, the vertical position of each of the chuck parts is calculated. Then, according to the database stored in the position data storage unit and the calculated vertical positions, the deviation of each of the chuck parts from the normal vertical position is calculated, and based on the calculated deviation, whether each of the plurality of chuck parts is abnormal is determined.

The spacing may be the same as the length obtained by dividing the distance from the uppermost clamp head to the lowermost clamp head by the number of the first sensors.

The conveying device may further include: a base, which supports the end effector in a manner that enables it to move forward and backward; and a support, which is arranged on the base and supports the at least two first sensors from the side in a direction perpendicular to the forward and backward direction and the up and down direction and at a position adjacent to the forward and backward path of the end effector.

The normal up-down position of each of the chuck parts stored in the database may be the position of the tip of the chuck part. The at least two first sensors may detect whether there is an object on the side of the tip of the plurality of chuck parts. The calculation unit may calculate the deviation of each of the tip of the plurality of chuck parts in the up-down direction relative to the normal up-down position based on the database, the obtained moving distance data and the detection data, and further determine whether the calculated deviation of each of the tip exceeds the first allowable value. When the calculation unit determines that at least one of the deviations of each of the tip exceeds the first allowable value, the control unit may stop the movement of the end effector.

The conveying device may further include: a warning device, which warns of an abnormality when the calculation unit determines that at least one of the deviation amounts of each of the tip portions exceeds the first allowable value.

The normal up-down position of each of the clip parts stored in the database may be the position of the tip of the clip part. The at least two first sensors may be located on the side of the tip of the plurality of clip parts to detect whether there is an object on the side. The calculation unit may calculate the position of each of the tip of the plurality of clip parts relative to the normal up-down direction based on the database, the obtained moving distance data and the detection data. The calculation unit calculates the deviation amount in the vertical direction, and calculates the tilt angle of each of the plurality of chuck parts relative to the horizontal direction according to the calculated deviation amount, and then determines whether the calculated tilt angle of each of the plurality of chuck parts exceeds the second allowable value. When the calculation unit determines that at least one of the tilt angles of each of the plurality of chuck parts exceeds the second allowable value, the control unit can stop the movement of the end effector.

The thickness data of the substrate can be stored in the position data storage unit, and the calculation unit can calculate the vertical position of each chuck unit based on the obtained moving distance data and the detection data, and then determine whether each of the multiple chuck units clamps the substrate based on the database stored in the position data storage unit, the thickness data of the substrate and the calculated vertical position.

The end effector may have a clamping part, and the clamping part clamps the substrate in batches from the side when the plurality of clamping parts clamp the substrate respectively. When all or part of the clamping parts clamp the substrate, the control part may clamp the substrate by the clamping part and keep the substrate clamped by the clamping part, and when the lowermost clamping part is in the first reference position, the end effector is raised relative to the at least two first sensors by at least the distance, or when the uppermost clamping part is in the second reference position, the end effector is lowered relative to the at least two first sensors by at least the distance.

The conveying device may further include: a base, which supports the end effector in a manner that enables it to move forward and backward; a first moving mechanism, which supports the base and can move in a direction perpendicular to the forward and backward direction and the up and down direction of the end effector; a support body, which supports the first moving mechanism in a manner that enables it to move; and a second sensor, which is disposed on the base and detects the inclination of the base in the forward and backward direction relative to the upper surface of the support body. When the output of the second sensor exceeds a third allowable value, the operation unit determines that the inclination of the base in the forward and backward direction relative to the support body is abnormal. When the operation unit determines that the inclination in the forward and backward direction is abnormal, the control unit may stop the movement of the end effector.

The second sensor may include: a light-emitting portion, which is disposed on the substrate and emits light in the advancing and retreating direction; a light-receiving portion, which is disposed on the substrate and faces the light-emitting portion in the advancing and retreating direction and receives the light from the light-emitting portion and measures the amount of the received light; and a light shielding plate, which is disposed on the supporting body and extends from the supporting body to between the light-emitting portion and the light-receiving portion to shield a part of the light from the light-emitting portion. When the inclination of the base relative to the support body in the advancing and retreating direction changes, the position of the light shielding plate relative to the light emitting part and the light receiving part may change, thereby the amount of light shielding the light emitting part may change. When the change of the light amount measured by the light receiving part exceeds the third allowable value, the calculation unit may determine that the inclination of the base relative to the support body in the advancing and retreating direction is abnormal.

The conveying device may further include: a first motor driving a second moving mechanism, the second moving mechanism causing the end effector to move forward and backward; and a second motor driving a third moving mechanism, the third moving mechanism causing the second moving mechanism to move up and down. The calculation unit may obtain torque value data from the first motor and the second motor respectively, and determine whether the torque value of the first motor obtained exceeds a first threshold value, and further determine whether the torque value of the second motor obtained exceeds a second threshold value. If the calculation unit determines that the torque value of the first motor exceeds the first threshold value, the control unit may stop the first motor, or if the calculation unit determines that the torque value of the second motor exceeds the second threshold value, the control unit may stop the second motor.

The control method of the conveying device of the second aspect of the present invention is a control method of the conveying device as follows, the conveying device comprises: an end actuator, having a plurality of clamping heads arranged in the up-down direction and clamping the substrates respectively; and at least two first sensors, arranged at a distance less than half of the distance from the topmost clamping head at the top to the bottommost clamping head at the bottom of the plurality of clamping heads, on the sides of the plurality of clamping heads, to detect whether there are objects on the sides, the conveying device comprises: an end actuator, having a plurality of clamping heads arranged in the up-down direction and clamping the substrates respectively; and at least two first sensors, arranged at a distance less than half of the distance from the topmost clamping head at the top to the bottommost clamping head at the bottom of the plurality of clamping heads, on the sides of the plurality of clamping heads, to detect whether there are objects on the sides, The control method of the device is characterized in that it includes the following steps: when the lowermost clamping head is in a first reference position, the end actuator is raised relative to the at least two first sensors by at least the distance, and the first reference position is lower than the lowermost first sensor of the at least two first sensors by the distance, or when the uppermost clamping head is in a second reference position, the end actuator is lowered relative to the at least two first sensors to The second reference position is higher than the uppermost first sensor of the at least two first sensors by a distance equal to the distance; During the step of raising or lowering the end actuator relative to the at least two first sensors, data of the movement distance of the end actuator relative to the first reference position or the second reference position is obtained, and detection data is obtained from the at least two first sensors; based on the obtained movement distance data and the at least two first sensors, Detecting data, calculating the up-down position of each of the chuck parts, and then calculating the deviation of each of the chuck parts from the normal up-down position based on the database storing the data of the normal up-down position of each of the chuck parts and the calculated up-down position, and determining whether each of the chuck parts has an abnormality based on the calculated deviation; and stopping the movement of the end effector when at least one of the chuck parts has an abnormality.

According to the structure of the present invention, the control unit causes the end effector to rise or fall relative to at least two first sensors by a distance equal to the arrangement distance of the at least two first sensors. Furthermore, the calculation unit uses the data of the movement distance of the end effector relative to the first reference position or the second reference position and the detection data of at least two first sensors to determine whether each of the plurality of chuck parts has abnormalities, and the aforementioned movement distance data and the detection data of the first sensors are obtained during the period of causing the end effector to rise or fall relative to the at least two first sensors. In the present invention, it is not necessary to raise or lower the end effector to a distance equal to the distance between the uppermost clamping head and the lowermost clamping head. It is sufficient to raise or lower the end effector to a distance equal to the distance between at least two first sensors. Therefore, it is possible to detect whether the height of each clamping head is abnormal in a short time.

1A, 1B: Transport robots

2: Transport system

3:FOUP

4: Loading port

10: Robot subject

11: The first straight-acting mechanism

12: Second direct-acting mechanism

15: Frame

20: End effector

21: Clip head

30: Framework

31: Photosensor (first sensor)

32,33: Pillars

34,35: beam components

40: Controller

41: Processor

42: Memory

43: Interface

44: Bus

45: Display device (warning device)

46: Control Department

47: Operation Department

50: Clamping part

60: Base

61: Tilt detection sensor

62: Support frame

63: The third direct-acting mechanism

64: Third sliding member (first moving mechanism)

65: Stand (support body)

111: First sliding member (second moving mechanism)

112: Motor (drive unit)

113: Linear guide rails

121: Second sliding member (third moving mechanism)

122: Motor (drive unit)

211,212: Gripping claws

213,214: Support pin

421: Location data storage unit

422: Judgment parameter storage unit

611: Illumination Department

612: Light receiving part

613: Sunshade

D1: Distance

D2: Diameter

L1: Length

P1, P2: spacing

S1,S2,S3,S4,S5: Steps

T1, T2: thickness

VIII: Region

W: Wafer (substrate)

X,Y,Z: Direction

Y1: Location

Z1: coordinates

Figure 1 is a perspective view of the transport robot of embodiment 1 of the present invention.

Figure 2 is a left side view of the transport system incorporating the transport robot of implementation example 1.

Figure 3 is an enlarged right side view of the front part of the transfer robot including the end effector of implementation example 1.

Figure 4 is a hardware structure diagram of the controller included in the transport robot of implementation example 1.

Figure 5 is a block diagram of the controller included in the transport robot of implementation example 1.

Figure 6 is a flow chart of the abnormality determination process performed by the controller included in the transport robot of implementation example 1.

Figure 7 is a block diagram of the controller included in the transport robot of implementation example 2.

Figure 8 is an enlarged left side view of the base and its vicinity included in the transfer robot of implementation mode 2.

Hereinafter, the conveying device and the control method of the conveying device of the embodiment of the present invention are described in detail with reference to the drawings. Furthermore, the same symbols are attached to the same or equivalent parts in the drawings. In addition, in the orthogonal coordinate system XYZ shown in the drawings, when the forward and backward direction of the robot body is set to the Y axis and the lifting direction of the robot body is set to the Z axis, the direction orthogonal to the Y axis and the Z axis is the X axis. Hereinafter, the coordinate system is appropriately cited for description.

(Implementation Example 1)

The transport device of implementation form 1 is a transport robot, which includes a plurality of grippers to transport a plurality of substrates in batches. In the transport robot, if the grippers are tilted, the wafer may be damaged, so a sensor and a controller for detecting whether the grippers are tilted are also included. The structure of the transport device of implementation form 1 is described below by taking a batch transport robot that transports a plurality of wafers in batches as an example. First, referring to Figures 1 and 2, the structure of the transport robot that is the detection object of the sensor and the control object of the controller is described.

FIG. 1 is a perspective view of the transport robot 1A of embodiment 1. FIG. 2 is a left side view of the transport system 2 in which the transport robot 1A is incorporated. Furthermore, for easy understanding, FIG. 2 shows the loading port 4 for placing the transport robot 1A and the FOUP (front opening unified pod) 3 in the transport system 2. In addition, in addition to showing the appearance, the internal structure is also shown. In addition, FIG. 1 and FIG. 2 show the transport robot 1A holding the wafer W.

As shown in FIG. 1 , the transport robot 1A includes a robot body 10 and an end effector 20. The end effector 20 is mounted on the robot body 10 and is used to clamp the wafer W.

The transport robot 1A is a robot that takes out a plurality of wafers W in batches from a FOUP 3, which is a container for accommodating wafers W, or puts a plurality of wafers W in batches into a FOUP 3. As shown in FIG. 2, the robot body 10 has a first linear motion mechanism 11 and a second linear motion mechanism 12. The first linear motion mechanism 11 makes the end effector 20 move linearly in the front-back direction so that the end effector 20 can enter and exit the FOUP 3. The second linear motion mechanism 12 makes the end effector 20 move linearly in the up-down direction so that the end effector 20 can lift or lower the wafers W in the FOUP 3.

The first linear motion mechanism 11 has a ball screw (hereinafter referred to as the first ball screw) not shown in the figure extending in the front-rear direction (i.e., the Y direction), a first slider 111 that moves in the Y direction by the rotation of the first ball screw, and a motor 112 (also referred to as the first motor) that rotates the first ball screw to move the first slider 111 to a position in the Y direction. In the first linear motion mechanism 11, the controller described later rotates the motor 112 in the desired direction by the desired amount of rotation, thereby moving the first slider 111 to a desired position in the Y direction. The second linear motion mechanism 12 is mounted on the upper side (i.e., the +Z side) of the first slider 111.

The second direct-acting mechanism 12 has a ball screw (hereinafter referred to as the second ball screw) that is not shown in the figure and extends in the up-down direction (i.e., the Z direction) and is different from the first ball screw, a second sliding member 121 that moves in the Z direction by the rotation of the second ball screw, and a motor 122 (also referred to as the second motor) that rotates the second ball screw to move the second sliding member 121 to the Z direction position.

As shown in FIG. 2, in the second direct-acting mechanism 12, a frame 15 for accommodating equipment, wires, pipes, etc. for driving the clamping part 50 is fixed on the front surface side (i.e., +Y side) of the second slider 121. Furthermore, an end effector 20 is installed on the +Y side of the frame 15. Therefore, when the rotation of the motor 112 of the first direct-acting mechanism 11 is controlled by the above-mentioned controller to move the first slider 111 of the first direct-acting mechanism 11 to the desired Y direction position, not only the second direct-acting mechanism 12 carried on the first slider 111 moves, but also the end effector 20 moves to the desired Y direction position.

Furthermore, in the second direct-acting mechanism 12, the controller causes the motor 122 of the second direct-acting mechanism 12 to rotate in the desired direction by the desired amount, thereby causing the second slider 121 to move to the desired position in the Z direction. The end effector 20 is mounted on the second slider 121 via the frame 15, so when the controller causes the second slider 121 to move to the desired position in the Z direction, the end effector 20 also moves to the desired position in the Z direction.

Furthermore, the first sliding member 111 and the second sliding member 121 are specific examples of the second moving mechanism and the third moving mechanism mentioned in the scope of the patent application. In addition, the motor 112 and the motor 122 are specific examples of the driving part mentioned in the scope of the patent application.

Thus, the end effector 20 is moved to the desired position in the Y direction and the Z direction by the first linear motion mechanism 11 and the second linear motion mechanism 12. For example, the end effector 20 is moved into the FOUP 3. The end effector 20 has a plurality of clamping heads 21 to clamp and transport a plurality of wafers W contained in the FOUP 3.

As shown in FIG. 1, each chuck portion 21 is formed in the shape of a fork having two blades and in the shape of a flat plate. The chuck portion 21 has the plate surface facing the vertical direction and the fork-shaped blade tip facing forward. Furthermore, the chuck portion 21 has gripping claws 211, 212 on the plate surface at the tip of the blades. In addition, the chuck portion 21 has support pins 213, 214 on the plate surface at the rear end of the fork. The robot body 10 is provided with a clamping portion 50, which clamps the rear end of the wafer W from the side when the chuck portion 21 lifts the wafer W. When the chuck part 21 clamps the wafer W in the clamping part 50, the wafer W is clamped between the gripping claws 211, 212 and the supporting pins 213, 214. In this way, the chuck part 21 stably transports the wafer W.

The end effector 20 has a plurality of such chuck parts 21. Specifically, the end effector 20 has the same number of chuck parts 21 as the maximum number of wafers W that can be accommodated in the FOUP 3 (e.g., 25 wafers). Thus, the end effector 20 can move all the wafers W accommodated in the FOUP 3 out in batches, or move the maximum number of wafers W accommodated in the FOUP 3 into the FOUP 3 in batches.

In addition, in the end effector 20, a plurality of wafers W in the FOUP 3 are transported in batches, so the chuck parts 21 are arranged in the vertical direction at a certain spacing P1 that is the same as the arrangement spacing of the wafers W in the FOUP 3. In addition, the chuck parts 21 are arranged so that the plate surfaces face the vertical direction and the plate surfaces extend in the horizontal direction as described above, and as a result, the chuck parts 21 are parallel to each other. In this way, in the end effector 20, the wafers W horizontally accommodated in the FOUP 3 can be lifted and transported without damaging them.

However, if the chuck 21 deteriorates over time due to long-term use of the end effector 20, or if the chuck 21 and other parts are replaced according to the type of FOUP 3, the chuck 21 may tilt in the front-back direction or the left-right direction. In addition, the distance P1 in the vertical direction may change. If the chuck 21 tilts or the distance P1 of the chuck 21 deviates from a certain value, the wafer W may be damaged.

Therefore, in order to suppress the damage of the wafer W, the transport robot 1A includes a photo sensor, and the controller determines abnormalities such as the tilt and spacing deviation of the chuck part 21 based on the output of the photo sensor.

In this case, the following method is considered: using a photo sensor disposed on the side of the end effector 20 to detect the inclination or spacing deviation of a plurality of chuck parts 21 arranged in the vertical direction. However, in this case, compared with the distance from the lower surface of the top chuck part 21 to the lower surface of the bottom chuck part 21 (the distance D1 shown in FIG. 3 described later) plus the thickness T1 of the chuck part 21, the end effector 20 needs to be raised and lowered more relative to the photo sensor. As a result, the measurement using the photo sensor takes time, and the determination of the abnormality of the chuck part 21 takes time.

Therefore, in the transport robot 1A, a plurality of photo sensors arranged in the vertical direction are used to determine the abnormality of the clamp head 21. Next, referring to Figures 3 to 5, the structure of the photo sensors and controller included in the transport robot 1A is described.

FIG. 3 is an enlarged right side view of the front part of the transport robot 1A including the end effector 20. FIG. 4 is a hardware structure diagram of the controller 40 included in the transport robot 1A. FIG. 5 is a block diagram of the controller 40. Furthermore, in FIG. 3, for easy understanding, the position of the photo sensor 31 is shown only on one of the pillars 32 included in the frame 30, but in fact, the light emitting part and the light receiving part of the photo sensor 31 are respectively provided on the pillars 32 and 33. The same is true for FIG. 1 and FIG. 2. In addition, in FIG. 4 and FIG. 5, for easy understanding, in addition to the controller 40, the structure of other equipment connected to the controller 40 is also shown.

As shown in FIG. 3 , the transport robot 1A further includes a frame 30 disposed at the front end portion of the robot body 10 and a plurality of photo sensors 31 supported by the frame 30 and disposed to detect the height of the chuck portion 21 included in the end effector 20.

In the transport robot 1A, the tip of the end effector 20 (hereinafter also referred to as the front end) is retracted to the plurality of photo sensors 31 mounted on the frame 30, and the end effector 20 is raised and lowered in this state, so that the plurality of photo sensors 31 detect each chuck portion 21 of the end effector 20. The frame 30 is formed in a square frame shape to present a state in which the end effector 20 can move forward and backward and can be raised and lowered.

Specifically, as shown in FIG. 1, the frame 30 has two pillars 32 and 33 extending in the vertical direction, and beam members 34 and 35 extending in the horizontal direction and connecting the upper and lower ends of the pillars 32 and 33. Moreover, the pillars 32 and 33 are sufficiently long in comparison with the length obtained by adding the thickness T1 of the chuck part 21 shown in FIG. 3 and the thickness T2 of the wafer W to the distance D1 in the vertical direction from the uppermost chuck part 21 of the end effector 20 to the lowermost chuck part 21. In addition, the beam members 34 and 35 are sufficiently long in comparison with the diameter D2 of the wafer W shown in FIG. 1. As a result, the frame 30 is a square frame shape in which the end effector 20 can move forward and backward in its internal space. In addition, it is a square frame shape in which the end effector 20 can be raised and lowered within its internal space.

In addition, in order to enable the multiple photoelectric sensors 31 in a stationary state to detect each clamping head 21 of the end effector 20 during lifting, as shown in Figure 3, the frame 30 is fixed to a portion of the transport robot 1A that does not move with the lifting of the end effector 20.

In detail, the transport robot 1A includes a base 60 for supporting the first linear motion mechanism 11, and a frame of a linear guide 113 is fixed on the base 60. The linear guide 113 guides the first slider 111 of the first linear motion mechanism 11 along the Y direction. The frame 30 is fixed on the base 60. In this way, the frame 30 is fixed to the following position: a position that is not related to the advance and retreat of the end effector 20 through the first slider 111 and is not related to the lifting and lowering of the end effector 20 through the second slider 121.

Furthermore, the frame 30 is arranged in front of and adjacent to the frame of the linear guide 113 so that a plurality of photo sensors 31 can detect the front end portion of each chuck portion 21 of the end effector 20. The length L1 of the frame 30 in the front-to-back direction is sufficiently smaller than the distance that the first slider 111 guided by the linear guide 113 can move forward. In addition, the end effector 20 is located at a position further forward than the first slider 111. Due to this positional relationship, when the first slider 111 moves forward and backward, (a) the entire chuck portion 21 of the end effector 20 and (b) the entire wafer W when the wafer W is clamped by the chuck portion 21 enter the internal space of the frame 30 or pass through the internal space of the frame 30. As a result, the pillars 32 and 33 of the frame 30 are located on the right or left side of the path (also called the advance and retreat path) of the end effector 20. Then, a plurality of photoelectric sensors 31 are arranged on the pillars 32 and 33 to detect the height of the chuck 21 of the end effector 20 advancing, retreating or ascending and descending on the path and the presence or absence of the wafer W.

Although not shown in the figure, each photo sensor 31 has a light emitting part and a light receiving part that receives the light beam emitted by the light emitting part. The light emitting part of the photo sensor 31 is set on either the support 32 or the support 33, and emits a light beam in the horizontal direction. In addition, the light receiving part of the photo sensor 31 is set at a position at the same height as the light receiving part of the other support 32 and 33, and receives the light beam. Then, each photo sensor 31 determines whether there is an object between the light emitting part and the light receiving part based on the amount of light detected by the light receiving part, and outputs whether there is an object. In detail, each photo sensor 31 outputs whether there is an object between the support 32 and 33. That is, the chuck portion 21 of the end effector 20 passes between the pillars 32 and 33, and as a result, each photo sensor 31 outputs whether the chuck portion 21 exists between the pillars 32 and 33. Alternatively, it outputs whether the wafer W exists between the pillars 32 and 33.

In addition, in order to detect the chuck portion 21 of the end effector 20 that rises and falls between the pillars 32 and 33, as shown in Figures 1 to 3, the photoelectric sensors 31 are arranged along the axis of the pillars 32 and 33 in the vertical direction at a spacing P2 (also called the second spacing), and the spacing P2 is greater than the spacing P1 of the chuck portion 21.

In detail, the photosensor 31 at the lowest position among the plurality of photosensors 31 is arranged at the same height as the following height: when the end actuator 20 moves to the reference position (also called the origin, called the first reference position in the scope of the patent application) by the second linear motion mechanism 12, the height of the reference position (the coordinate Z1 in the Z direction shown in FIG. 3) is higher than the height of the reference position by a distance P2. Then, the other photosensors 31 are arranged upward from the photosensor 31 at the lowest position with a distance P2.

Here, the spacing P2 has the same length as the following distance: the distance D1 from the center of the uppermost clamp portion 21 in the vertical direction to the center of the lowermost clamp portion 21 in the vertical direction divided by the number of photo sensors 31.

Since the photo sensors 31 are arranged in this way, if the end effector 20 rises from the reference position by a height equal to the spacing P2, all the chucks 21 of the end effector 20 pass through the side of any photo sensor 31. As a result, the plurality of photo sensors 31 can detect the height of all the chucks 21 of the end effector 20 and the presence or absence of the wafer W in each chuck 21.

In addition, it is ideal that the number of photo sensors 31 is a divisor of the maximum number of wafers W that can be accommodated in FOUP 3. However, it is ideal that the divisor does not include the maximum number. The reason is that if the number is such, the distance that the end effector 20 is raised from the reference position can be minimized. In addition, there is no need to raise the end effector 20 too much. In the transport robot 1A, the maximum number of wafers W that can be accommodated in FOUP 3 is 25. Therefore, in order to meet the above conditions, only 5 photo sensors 31 are provided in the transport robot 1A. Thus, in the transport robot 1A, the above-mentioned distance P2 is made smaller than the distance D1, thereby shortening the distance that the end effector 20 rises in order to detect the height of the chuck 21 and the presence or absence of the wafer W.

Each photo sensor 31 detects the presence of the chuck portion 21 or the wafer W (i.e., the presence of an object blocking the light from the light-emitting portion of the photo sensor 31) and sends the detection data to the controller 40.

Furthermore, the photoelectric sensor 31 is a specific example of the first sensor mentioned in the scope of the patent application.

As shown in FIG. 4 , the controller 40 includes a processor 41 , a memory 42 , and an interface 43 . Then, the processor 41 , the memory 42 , and the interface 43 are connected via a bus 44 .

The interface 43 connects the processor 41 and the memory 42 to other devices so as to communicate with other devices. Specifically, the interface 43 is connected to the plurality of photoelectric sensors 31, the motor 112 of the first linear motion mechanism 11, and the motor 122 of the second linear motion mechanism 12 included in the robot body 10. In addition, it is connected to the display device 45. Thus, the interface 43 enables these devices to send and receive data with the processor 41 and the memory 42.

The processor 41 and the memory 42 constitute a computer. The controller 40 performs various processes for controlling the motor 112 of the first linear motion mechanism 11 and the motor 122 of the second linear motion mechanism 12 of the robot body 10 by reading and executing various programs stored in the memory 42 by the processor 41. For example, the controller 40 performs abnormality determination processing of the end effector 20 to determine abnormalities such as inclination and spacing deviation of the chuck part 21 based on the output of the above-mentioned photo sensor 31 by reading and executing the abnormality determination program stored in the memory 42. The controller 40 includes a control unit 46 and a calculation unit 47 shown in FIG. 5 to perform the processing. Next, the structures are explained.

The control unit 46 controls each part of the robot body 10. For example, the control unit 46 controls the motor 112 of the first linear motion mechanism 11 and the motor 122 of the second linear motion mechanism 12. In this way, the first slider 111 and the second slider 121 are moved, and the end effector 20 is moved forward or backward or raised and lowered to the desired position. In addition, the control unit 46 sends the moving distance data calculated from the above-mentioned reference position (origin) to the calculation unit 47.

In this regard, the calculation unit 47 receives the moving distance data of the end effector 20 from the control unit 46. In addition, the calculation unit 47 receives the detection data of the object from each photo sensor 31.

Here, the detection data of the object refers to the detection data of the chuck part 21 of the end effector 20 or the wafer W. Since the light emitting part and the light receiving part of the photo sensor 31 are respectively arranged on the pillars 32 and 33, the object that blocks the light beam of the photo sensor 31 is limited to the chuck part 21 of the end effector 20 or the wafer W clamped by the chuck part 21. The calculation unit 47 receives the detection data of the chuck part 21 or the wafer W.

When the calculation unit 47 receives the movement distance data of the end effector 20 and the detection data of the object, it obtains the position of the clamping head 21 of the end effector 20 and the presence or absence of abnormality of the clamping head 21 based on the received movement distance data of the end effector 20 and the detection data of the object. In this way, the abnormality determination processing of the end effector 20 is performed to determine abnormalities such as the tilt and spacing deviation of the clamping head 21. Next, referring to Figure 6, the abnormality determination processing of the end effector 20 is described in more detail.

Figure 6 is a flow chart of the abnormality determination process performed by the controller 40.

In the transport robot 1A, (1) when the end effector 20 is advanced to take out the wafer W contained in the FOUP 3, or (2) when the end effector 20 is advanced with the chuck 21 holding the wafer W to contain the wafer W in the FOUP 3, if the chuck 21 is tilted or the distance P1 of the chuck 21 is deviated, the wafer W may be damaged.

Therefore, the controller 40 performs the abnormality determination process shown in FIG. 6 of the end effector 20 using the photo sensor 31 before performing the (1) wafer W removal operation and the (2) wafer W storage operation. Specifically, when the front end portion is at a position further forward than the frame 30 and the position is at the reference position (origin) of the end effector 20, the controller 40 retreats the end effector 20 while maintaining the height of the reference position (origin) before performing the above-mentioned (1) or (2) operation, and when the position of the front end portion of the chuck portion 21 in the front-rear direction (i.e., the Y coordinate) coincides with the Y coordinate of the pillars 32 and 33, the controller determines that the abnormality determination process can be performed, and performs the abnormality determination process. Specifically, the processor 41 reads out and executes the abnormality determination program stored in the memory 42. As a result, the abnormality determination processing flow of the end executor 20 starts.

When the abnormality determination process of the end effector 20 begins, the front end of the chuck 21 is in a position overlapping with the pillars 32 and 33 when viewed from the left and right directions, and is in a state that can be detected by the photo sensor 31. Based on this, as shown in FIG. 6, the controller 40 first raises the end effector 20 and obtains the rise distance data and the detection data of the photo sensor 31 (step S1).

In detail, the control unit 46 causes the motor 122 of the second linear motion mechanism 12 to rotate in the positive direction at a certain rotation speed, thereby causing the second slider 121 to rise at a certain speed. In this way, the end effector 20 is raised at a certain speed. During the rise of the end effector 20, the control unit 46 causes the end effector 20 to rise only by a distance that is the same as the distance P2 at which the photosensors 31 are arranged in the vertical direction. Even if the end effector 20 is raised by only this distance, since the photosensors 31 are arranged in the vertical direction at a distance P2, each chuck portion 21 can be detected by any photosensor 31.

In parallel with the rise of the end effector 20, the calculation unit 47 obtains the moving distance data of the end effector 20 from the control unit 46 every certain time (that is, the data of the distance the end effector 20 has risen from the start of step S1 to the present). In addition, the calculation unit 47 obtains the detection data from each photo sensor 31 every certain time. The calculation unit 47 can obtain such data almost at any time by setting the certain time to a short time.

Next, the calculation unit 47 calculates the height of each clamping head 21 (step S2).

In step S1, the end effector 20 rises at a constant speed by a distance equal to the pitch P2, whereby the front end portion of the chuck portion 21 moves relative to each photosensor 31. Alternatively, when the chuck portion 21 holds a wafer W, the wafer W moves relative to each photosensor 31. Therefore, the calculation unit 47 obtains the following data by obtaining the rising distance data and the detection data of the photosensor 31 in step S1: data on the presence or absence of an object in the length obtained by multiplying the number of photosensors 31 by the pitch P2 in the vertical direction at the position of each photosensor 31 in the front-back direction (position Y1 shown in FIG. 3). The calculation unit 47 generates mapping data indicating the presence or absence of an object in the up-down direction based on such data. Then, the calculation unit 47 calculates the height of the upper surface or lower surface of each chuck portion 21 based on the height of the upper surface or lower surface of the portion where the object exists in the mapping data.

Next, as shown in FIG. 6, the calculation unit 47 determines whether any of the chuck parts 21 has a height abnormality (step S3).

The memory 42 includes the position data storage unit 421 and the judgment parameter storage unit 422 shown in FIG. 5. The position data storage unit 421 stores normal height data of the upper surface or lower surface of each chuck unit 21 (also referred to as a database in the scope of the patent application) and normal thickness data of the thickness T2 of the wafer W (also referred to as substrate thickness data in the scope of the patent application). In addition, the judgment parameter storage unit 422 stores a threshold value of the deviation amount calculated from the ideal height of the chuck unit 21 that should be judged as non-abnormal (also referred to as the first allowable value in the scope of the patent application).

The calculation unit 47 reads the normal height data of the upper surface or lower surface of each chuck unit 21 and the normal thickness data of the thickness T2 of the wafer W from the position data storage unit 421, and compares the read normal height data of the upper surface or lower surface of each chuck unit 21 with the height data of the upper surface or lower surface of each chuck unit 21 obtained in step S2, and obtains the deviation of the height of the upper surface or lower surface of each chuck unit 21 from the normal height.

Furthermore, the calculation unit 47 reads the threshold value of the deviation amount from the judgment parameter storage unit 422, and judges whether any of the deviation amounts of the height of the upper surface or the lower surface of each chuck portion 21 calculated from the normal height is greater than the threshold value of the deviation amount read. Then, when the calculation unit 47 judges that the deviation amount is greater than the threshold value of the deviation amount read, it judges that any of the chuck portions 21 has a height abnormality. Then, the calculation unit 47 further judges whether the chuck portion 21 judged to have an abnormality is tilted or the spacing P1 has deviated. On the other hand, when the calculation unit 47 determines that the deviation amount is less than the threshold value of the read deviation amount, it determines that there is no height abnormality in any of the chuck parts 21. In this way, the calculation unit 47 performs the determination of whether any of the chuck parts 21 has a height abnormality in step S3.

Furthermore, in step S3, the calculation unit 47 determines that the wafer W is clamped by the chuck portion 21 in the following case: in the height data of the upper surface of each chuck portion 21 obtained in step S2, the height data of the upper surface of the chuck portion 21 is higher than the normal height of the upper surface of each chuck portion 21 read by a normal thickness value corresponding to the thickness T2 of the wafer W read. Here, in the case where the normal height of the upper surface of each chuck portion 21 is higher than the normal height of the upper surface of each chuck portion 21 read by a normal thickness value corresponding to the thickness T2 of the wafer W read, it is set as a deviation within the threshold value of the above-mentioned deviation amount. Then, the calculation unit 47 outputs the determination result of the presence or absence of the wafer W to other equipment (for example, the display device 45 shown in FIG. 5 ).

In the determination of step S3, when it is determined that any of the chuck parts 21 has an abnormal height ("Yes" in step S3), the calculation unit 47 sends an abnormal signal to the control unit 46, and the control unit 46 stops the movement of the end effector 20. In this way, the end effector 20 is prevented from entering the FOUP 3 and the wafer W is damaged. In addition, the calculation unit 47 sends an abnormal signal to the display device 45 and causes it to display a warning (step S4). In this way, the calculation unit 47 reminds the user to replace or adjust the chuck part 21. At this time, the number of the chuck part 21 determined to have an abnormal height (for example, the number counted from the top) can be displayed on the display device 45. Furthermore, the display device 45 is an example of a warning device for warning of abnormality mentioned in the scope of the patent application, and may also be a warning light, for example.

Then, the calculation unit 47 ends the abnormality determination process. After the abnormality determination process is completed, the control unit 46 keeps the movement of the transport robot 1A stopped until the user of the transport robot 1A returns it to the origin and replaces and adjusts the chuck part 21 and cancels the warning.

On the other hand, in the judgment of step S3, when it is judged that there is no height abnormality in any chuck part 21 ("No" in step S3), the calculation unit 47 sends the result to the control unit 46, and the control unit 46 makes the end effector 20 descend (step S5) and returns to the state before the end effector 20 rises in step S1. Then, the calculation unit 47 ends the abnormality judgment processing. The control unit 46 infers that there is no abnormality in the chuck part 21 and there is no risk of damage to the wafer W, and makes the robot body 10 perform the above-mentioned (1) wafer W removal action or (2) wafer W storage action.

As described above, in the handling robot 1A of the embodiment 1, the control unit 46 controls the motor 122 of the second linear mechanism 12 to raise the end effector 20 by a distance equal to the spacing P2, which is smaller than the distance D1, which is the distance from the topmost chuck portion 21 to the bottommost chuck portion 21 among the plurality of chuck portions 21. Furthermore, the calculation unit 47 uses the following data to find out whether each chuck portion 21 has an abnormality: the rising distance data of the end effector 20 obtained during the period of raising the end effector 20 by the spacing P2 and the detection data. In the transport robot 1A, it is not necessary to raise the end effector 20 by the distance P1, but it is sufficient to raise or lower the end effector 20 by at least the distance P2. Therefore, in the transport robot 1A, it is possible to detect whether the height of each chuck 21 is abnormal in a short time.

Specifically, in the transport robot 1A, as a result of including 5 photo sensors 31, the spacing P2 is 1/5 of the above distance D1. Therefore, in the transport robot 1A, compared with raising the end effector 20 by the spacing P1 so that the photo sensor 31 detects the shape of the chuck part 21, it is possible to detect whether the height of each chuck part 21 is abnormal in a short time.

In addition, in the transport robot 1A, when the calculation unit 47 determines that there is a high degree of abnormality in any of the chuck units 21, the movement of the end effector 20 is stopped. As a result, in the transport robot 1A, the situation in which the abnormal chuck unit 21 enters the FOUP 3 and causes the wafer W to be damaged can be suppressed. For example, the wafer W is not easily damaged.

In the transport robot 1A, the photo sensor 31 is fixed to the base 60 supporting the first linear motion mechanism 11 via the frame 30. In the transport robot 1A, the base 60 is a part of the robot body 10, so the time spent on detecting the height abnormality of the chuck portion 21 is shorter than when the transport robot is moved to other equipment and the height of the chuck portion is measured by the equipment.

Furthermore, since the frame 30 is located in front of the first linear motion mechanism 11 and adjacent to it, the distance that the end effector 20 moves in order to detect the height abnormality of the chuck portion 21 is shorter. Therefore, the time spent on detecting the height abnormality of the chuck portion 21 is shorter.

In the transport robot 1A, since the photo sensor 31 detects the front end portion of the chuck portion 21 of the end effector 20, when the chuck portion 21 is tilted, the tilt can be easily detected.

(Transformed form)

Furthermore, in the implementation sample 1, in the abnormality determination process of the end effector 20, the deviation of the height of the upper surface or lower surface of each chuck portion 21 from the normal height is calculated, and the chuck portion 21 is determined based on the deviation to determine whether there is a height abnormality. However, the determination of whether there is a height abnormality of the chuck portion 21 can also be performed based on the tilt angle of the chuck portion 21.

For example, the calculation unit 47 can also calculate the tilt angle of each chuck portion 21 based on the deviation of the height of the upper surface or lower surface of each chuck portion 21 from the normal height and the length from the front end of the chuck portion 21 (as the measurement position of the photo sensor 31) to the base end of the chuck portion 21. If the tilt angle exceeds the allowable value (referred to as the second allowable value in the patent application scope), it can be determined that the chuck portion 21 is abnormal.

In addition, in embodiment 1, when the clamping part 50 clamps the wafer W, the chuck part 21 clamps the wafer W by using the gripping claws 211, 212 and the supporting pins 213, 214. However, the clamping part 50 is not only used when the chuck part 21 clamps the wafer W.

When the abnormality determination process of the end effector 20 is performed while the chuck portion 21 is clamping the wafer W, the clamping portion 50 may be used when the end effector 20 is ascending in step S1. That is, the clamping portion 50 is moved forward and backward in the front-back direction by a direct-acting mechanism (not shown), but before the end effector 20 is ascending in step S1, the control portion 46 may control the direct-acting mechanism (not shown) to move the clamping portion 50 forward to clamp the wafer W. Furthermore, the end effector 20 may be ascended in step S1 while the wafer W is clamped. If the end effector 20 is raised in this way, the wafer W will not deviate, so the photo sensor 31 can accurately detect the wafer W.

(Implementation Example 2)

In the embodiment 1, in order to suppress the damage of the wafer W, the calculation unit 47 determines whether each chuck part 21 has an abnormality. However, the present invention is not limited to this. In the present invention, in order to suppress the damage of the wafer W, the calculation unit 47 can further determine whether the base 60 supporting the first linear motion mechanism 11 is tilted.

In the conveying robot 1B of the implementation form 2, a tilt detection sensor for detecting the tilt of the base 60 is included. Moreover, the calculation unit 47 determines whether the tilt of the base 60 is allowed based on the detection result of the tilt detection sensor.

The structure of the transport robot 1B of Implementation Example 2 is described below with reference to Figures 7 and 8. In Implementation Example 2, the description is centered on the structure that is different from Implementation Example 1.

FIG. 7 is a block diagram of the controller 40 included in the transport robot 1B. FIG. 8 is an enlarged left side view of the base 60 and its vicinity included in the transport robot 1B. Furthermore, in FIG. 7, in addition to the controller 40, the structure of other equipment connected to the controller 40 is also shown for easy understanding. In addition, in FIG. 8, the VIII area shown in FIG. 2 included in the transport robot 1B is enlarged.

As shown in FIG. 7 , the transport robot 1B includes a tilt detection sensor 61 in addition to the photoelectric sensor 31 provided on the robot body 10 .

First, the inclination of the base 60, which is the detection object of the inclination detection sensor 61, is described. As described in the embodiment 1, the base 60 supports the first linear motion mechanism 11. In detail, as shown in FIG. 2, the base 60 is formed in a flat plate shape, and is further supported by a support frame 62 disposed thereunder. Then, the support frame 62 is supported by a third slide 64 (also referred to as a slide) included in the third linear motion mechanism 63. The third linear motion mechanism 63 has a rail fixed to a stand 65 and extending in the left-right direction (i.e., the X direction), and the third slide 64 moves linearly along the rail. The third slide 64 moves linearly in the X direction, thereby causing the transport robot 1B supported by the base 60 to move linearly in the X direction. In this way, a conveying system 2 is realized that moves the end effector 20 in the XYZ direction.

However, on the base 60, the frame 15 and the end effector 20 are moved by the first linear motion mechanism 11 and the second linear motion mechanism 12. As a result, deformation, positional deviation and other undesirable conditions may occur due to years of degradation. Therefore, the base 60 may sometimes tilt relative to the third slider 64. When the base 60 tilts relative to the third slider 64, not only the chuck portion 21 of the end effector 20 tilts, but also the frame 30 supporting the photo sensor 31 described in the implementation sample 1 tilts. As a result, it is difficult to use the photo sensor 31 to detect the tilt of the chuck portion 21 caused by the tilt of the base 60. Therefore, a tilt detection sensor 61 is provided in the transport robot 1B. Furthermore, the tilt detection sensor 61 is a specific example of the second sensor mentioned in the patent application scope.

As shown in FIG. 8 , the tilt detection sensor 61 has a light emitting portion 611 and a light receiving portion 612 disposed on a base 60, and a light shielding plate 613 disposed on a stand 65 and shielding light from the light emitting portion between the light emitting portion 611 and the light receiving portion 612.

The light-emitting portion 611 is disposed at the lower portion of the base 60 and emits a light beam to the rear. In contrast, the light-receiving portion 612 is disposed at the lower portion of the base 60 and further rearward than the light-emitting portion 611. Furthermore, the light beam emitted by the light-emitting portion 611 is received.

In addition, the light-emitting portion 611 emits a light beam in a horizontal direction when the surface of the base 60 is horizontal. Moreover, the light-receiving portion 612 faces the light-emitting portion 611 in the Y direction.

On the other hand, the light shielding plate 613 is disposed on the +Z plane of the stand 65. Moreover, it has a tip extending parallel to the YZ plane. The tip extends between the light emitting portion 611 and the light receiving portion 612. Moreover, when the plate surface of the base 60 is horizontal, the light shielding plate 613 blocks half of the light beam of the light emitting portion 611. In this state, when the plate surface of the base 60 is tilted in the Y direction, the tip of the light shielding plate 613 blocks more light beams. That is, the light shielding rate of the light shielding plate 613 to the light beam changes. The light receiving portion 612 measures this amount of light and sends it to the calculation unit 47 shown in Figure 7.

The calculation unit 47 receives the light quantity data measured by the light receiving unit 612 from the tilt detection sensor 61. On the other hand, the data of the normal value of the light quantity and the allowable value of the light quantity change (referred to as the third allowable value in the scope of the patent application) are stored in the judgment parameter storage unit 422. The calculation unit 47 reads the data of the normal value of the light quantity and the allowable value of the light quantity change, and calculates the change amount of the received light quantity data from the normal value of the light quantity. Then, the calculation unit 47 determines whether the calculated change amount exceeds the allowable value. In this way, the calculation unit 47 determines whether the substrate 60 is tilted relative to the +Z plane of the stage 65.

When the calculated variation exceeds the allowable value, the calculation unit 47 determines that the inclination of the substrate 60 relative to the stage 65 is large, and sends an abnormal signal to the control unit 46. When the control unit 46 receives the abnormal signal, it stops the movement of the end effector 20, and sends an abnormal signal to the display device 45 to display a warning, similar to step S4 of the abnormal determination processing of the end effector 20 described in the implementation form 1. During the startup period, the transport robot 1B of the implementation form 2 always executes the determination performed by the calculation unit 47. In this way, in the transport robot 1B, the damage of the wafer W caused by the inclination of the substrate 60 can be suppressed.

The above-mentioned tilt detection sensor 61 is arranged at the rear part of the substrate 60 in the front-back direction. In detail, as shown in FIG. 2, the substrate 60 is supported by the third slider 64 via the support frame 62. The third slider 64 is located below the center of the substrate 60 in the front-back direction. On the other hand, the VIII region shown in FIG. 2 is located at the rear part of the substrate 60, from which it can be seen that the tilt detection sensor 61 is arranged at the rear part of the substrate 60 further back than the third slider 64. As a result, the tilt detection sensor 61 is easily affected by the tilt of the substrate 60 in the front-back direction, and thus the tilt is easily detected. As a result, in the transfer robot 1B, the damage of the wafer W caused by the tilt of the substrate 60 is more effectively suppressed.

Furthermore, the third sliding member 64 is a specific example of the first moving mechanism mentioned in the scope of the patent application. The stand 65 is a specific example of the supporting body mentioned in the scope of the patent application.

As described above, in the transport robot 1B of the embodiment 2, based on the output of the tilt detection sensor 61 provided on the substrate 60 and the stage 65, the calculation unit 47 determines whether the substrate 60 is tilted relative to the upper surface of the stage 65. As a result, in the transport robot 1B, it is not easy to cause damage to the wafer W due to the tilt of the substrate 60.

(Implementation Example 3)

In implementation sample 1, in order to suppress the damage of the wafer W, the calculation unit 47 determines whether each chuck part 21 has an abnormality. In addition, in implementation sample 2, the calculation unit 47 determines whether the base 60 is tilted. However, the present invention is not limited to this. In the present invention, in order to suppress the damage of the wafer W, the calculation unit 47 can also determine whether the motor 112 of the first linear mechanism 11 and the motor 122 of the second linear mechanism 12 have an abnormality.

Based on the structure of implementation example 2, the calculation unit 47 of the transport robot of implementation example 3 determines whether the motor 112, the motor 122, etc. have abnormalities. The structure of the transport robot of implementation example 3 is described below. In implementation example 3, the description is centered on the structure that is different from implementation examples 1 and 2.

Furthermore, the block diagram of the transport robot of implementation example 3 is the same as the transport robot 1B of implementation example 2, so the diagram is omitted.

The motor 112 of the first direct-acting mechanism 11 and the motor 122 of the second direct-acting mechanism 12 each have a torque measuring unit, and send the measured torque value data to the calculation unit 47. In addition, the third direct-acting mechanism 63 described in the embodiment 2 is also provided with a motor for moving the third slide 64. The motor of the third direct-acting mechanism 63 also has a torque measuring unit, and sends the measured torque value data to the calculation unit 47.

On the other hand, the first threshold, second threshold, and third threshold of the torque values of the motor 112 of the first direct-acting mechanism 11, the motor 122 of the second direct-acting mechanism 12, and the motor 63 of the third direct-acting mechanism are stored in the judgment parameter storage unit 422. The calculation unit 47 reads the first threshold, the second threshold, and the third threshold from the judgment parameter storage unit 422. Then, the calculation unit 47 receives each torque value data from each of the motor 112 of the first direct-acting mechanism 11, the motor 122 of the second direct-acting mechanism 12, and the motor 63 of the third direct-acting mechanism, and determines whether each of the data exceeds each of the first threshold, the second threshold, and the third threshold.

When the torque value data of the motor 112 of the first linear motion mechanism 11 exceeds the first threshold value, the calculation unit 47 sends a first torque abnormality signal to the control unit 46. When the control unit 46 receives the first torque abnormality signal, it stops the operation of the first linear motion mechanism 11 and displays a warning on the display device 45, the warning content of which is that there is an abnormality in the first linear motion mechanism 11.

Similarly, when the torque value data of the motor 122 of the second direct-acting mechanism 12 exceeds the second threshold value, the calculation unit 47 sends a second torque abnormality signal to the control unit 46. When the control unit 46 receives the second torque abnormality signal, it stops the action of the second direct-acting mechanism 12 and displays a warning on the display device 45, the warning content of which is that there is an abnormality in the second direct-acting mechanism 12.

Furthermore, when the torque value data of the motor of the third direct-acting mechanism 63 exceeds the third threshold value, the calculation unit 47 sends a third torque abnormality signal to the control unit 46. When the control unit 46 receives the third torque abnormality signal, it stops the action of the third direct-acting mechanism 63 and displays a warning on the display device 45, the warning content of which is that there is an abnormality in the third direct-acting mechanism 63.

As described above, in the transport robot of implementation form 3, the first direct motion mechanism 11, the second direct motion mechanism 12, and the third direct motion mechanism 63 are detected for each abnormality based on the torque values of the motor 112 of the first direct motion mechanism 11, the motor 122 of the second direct motion mechanism 12, and the motor 63 of the third direct motion mechanism. In the transport robot of implementation form 3, the operation is stopped when an abnormality is detected, thereby preventing the wafer W from being damaged during transport.

The above is an explanation of the conveying device and the control method of the conveying device of the embodiments 1 to 3 of the present invention, taking the conveying robot 1A and the conveying robot 1B as examples, but the conveying device and the control method of the conveying device are not limited to these.

For example, in Embodiments 1 to 3, photo sensors 31 are mounted on the frame 30, but the present invention is not limited thereto. In the present invention, the photo sensors 31 may be at least two first sensors as follows: the at least two first sensors are arranged at a distance P2 less than half of the distance D1 from the topmost clamp portion 21 to the bottommost clamp portion 21 among the plurality of clamp portions 21, and are located on the sides of the plurality of clamp portions 21 to detect whether an object exists on the sides. The photo sensors 31 may be located on the sides of the plurality of clamp portions 21, and therefore may be mounted on the pillars 32 and 33 without the beam members 34 and 35. In addition, the photo sensor 31 can also be installed on either of the pillars 32 and 33. As long as it is in this form, it can be located on the side of multiple chuck parts 21 by the advance and retreat of the end effector 20. As a result, the photo sensor 31 can detect the presence or absence of the chuck part 21.

In addition, in embodiments 1 to 3, the photosensor 31 includes a light-emitting part and a light-receiving part that are separately arranged, but the present invention is not limited to this. In the present invention, as described above, the photosensor 31 only needs to be a sensor that detects whether there is an object on the side. For example, the photosensor 31 can also be a reflective sensor as follows: the light-emitting part and the light-receiving part are arranged in a single frame and the light-receiving part receives reflected light from the object to be detected. In addition, the photosensor 31 can also be a retro-reflective sensor as follows: the light-emitting part and the light-receiving part are arranged in a single frame and further include a reflective part that is separately arranged from the light-emitting part and the light-receiving part.

Furthermore, in Embodiment 1 to Embodiment 3, five photosensors 31 are provided. However, the present invention is not limited thereto. In the present invention, as described above, at least two photosensors 31 are sufficient. For example, there may be two photosensors 31. Even in this case, the end effector 20 only needs to rise from the height of the origin (coordinate Z1 in the Z direction shown in FIG. 3) by half the distance D1. Furthermore, it is described in Embodiment 1 that it is ideal that the number of photosensors 31 is a divisor of the maximum number of wafers W that can be accommodated in FOUP 3. However, it is ideal that the divisor does not include the above-mentioned maximum number of wafers.

In implementation examples 1 to 3, when the chuck portion 21 is detected by the photosensor 31, the end effector 20 rises from the height of the origin (the coordinate Z1 in the Z direction shown in FIG. 3). However, the present invention is not limited to this. In the present invention, when the chuck portion 21 is detected by the photosensor 31, the end effector 20 can be raised by at least the distance P2 relative to at least two first sensors when the lowest chuck portion 21 is located at a first reference position. The first reference position is lower than the lowest first sensor among the plurality of photosensors 31 (i.e., the at least two first sensors mentioned in the present invention) by the distance P2. Therefore, the end effector 20 can also start to rise from a position higher than the origin.

Furthermore, in the present invention, when the chuck portion 21 is detected by the photoelectric sensor 31, the end effector 20 can be not only raised but also lowered. That is, in the present invention, the end effector 20 can be lowered at least by the distance P2 relative to at least two first sensors when the uppermost chuck portion 21 is located at the second reference position, and the second reference position is higher than the uppermost first sensor among the plurality of photoelectric sensors 31 (i.e., the at least two first sensors mentioned in the present invention) by the distance P2.

In the embodiment, the chuck part 21 has gripping claws 211, 212 and support pins 213, 214. Moreover, the chuck part 21 clamps the wafer W. However, the present invention is not limited to this. In the present invention, the chuck part 21 only needs to be able to clamp the substrate. Therefore, in the present invention, the specific part of the chuck part 21 that clamps the substrate is an arbitrary part. For example, the chuck part 21 can also use a vacuum suction cup to clamp the wafer W. In addition, the specific shape of the chuck part 21 can also be an arbitrary shape. For example, the chuck part 21 can also have a rectangular shape that can carry a substrate instead of a fork shape. Furthermore, the wafer W as the clamping object can also be other substrates such as a glass substrate.

The present invention can adopt various implementation modes and variations without departing from the broad spirit and scope of the present invention. In addition, the above-mentioned modes are only used to illustrate the present invention, not to limit the scope of the present invention. That is, the scope of the present invention is shown by the scope of the patent application rather than the implementation mode. Moreover, various variations implemented within the scope of the patent application and the scope of the invention meaning equivalent thereto are deemed to be within the scope of the present invention.

1A: Transport robot

10: Robot subject

11: The first straight-acting mechanism

20: End effector

21: Clip head

30: Framework

31: Photosensor (first sensor)

32,33: Pillars

34,35: beam components

50: Clamping part

60: Base

113: Linear guide rails

D1: Distance

L1: Length

P1, P2: spacing

T1, T2: thickness

X,Y,Z: Direction

Y1: Location

Z1: coordinates

Claims (12)

A conveying device, comprising: An end actuator, having a plurality of clamping heads arranged in the vertical direction and clamping substrates respectively; At least two first sensors, arranged at a distance less than half of the distance from the topmost clamping head located at the top to the bottommost clamping head located at the bottom of the plurality of clamping heads, detecting whether there are objects on the sides of the plurality of clamping heads; A position data storage unit, storing a database, which stores data on the normal vertical position of each of the plurality of clamping heads; The control unit, when the lowermost clamping head is in a first reference position, causes the end actuator to rise relative to the at least two first sensors by at least the distance, wherein the first reference position is lower than the lowermost first sensor among the at least two first sensors by the distance, or when the uppermost clamping head is in a second reference position, causes the end actuator to descend relative to the at least two first sensors by at least the distance, wherein the second reference position is higher than the uppermost first sensor among the at least two first sensors by the distance; and The calculation unit obtains the data of the movement distance of the end effector relative to the first reference position or the second reference position from the control unit while the end effector is raised or lowered relative to the at least two first sensors, and obtains detection data from the at least two first sensors, calculates the vertical position of each chuck based on the obtained movement distance data and the detection data, and further calculates the deviation of each chuck from the normal vertical position based on the database stored in the position data storage unit and the calculated vertical positions, and finds out whether each of the plurality of chucks has an abnormality based on the calculated deviation. The conveying device as described in claim 1, wherein, the spacing is the same as the length obtained by dividing the distance from the uppermost clamp head to the lowermost clamp head by the number of the first sensors. The conveying device as described in claim 1 or 2 further comprises: A base, which supports the end effector in a manner that enables it to move forward and backward; and A support, which is disposed on the base and supports the at least two first sensors from a side in a direction perpendicular to the forward and backward direction and the up and down direction and at a position adjacent to the forward and backward path of the end effector. The conveying device as described in claim 1 or 2, wherein, the normal vertical position of each of the clamping parts stored in the database is the position of the tip of the clamping part, the at least two first sensors are located on the side of the tip of the plurality of clamping parts to detect whether there is an object on the side, the calculation unit calculates the deviation of each of the tip of the plurality of clamping parts in the vertical direction relative to the normal vertical position based on the database, the obtained moving distance data and the detection data, and further determines whether the calculated deviation of each of the tip exceeds the first allowable value, when the calculation unit determines that at least one of the deviations of each of the tip exceeds the first allowable value, the control unit stops the movement of the end effector. The conveying device as described in claim 4 further comprises: A warning device, which warns of an abnormality when the calculation unit determines that at least one of the deviation amounts of each of the tip portions exceeds the first allowable value. A conveying device as described in claim 1 or 2, wherein, the normal vertical position of each of the clamping parts stored in the database is the position of the tip of the clamping part, the at least two first sensors are located on the side of the tip of the plurality of clamping parts to detect whether there is an object on the side, the calculation unit calculates the vertical deviation of each of the tip of the plurality of clamping parts relative to the normal vertical position based on the database, the obtained moving distance data and the detection data, calculates the tilt angle of each of the plurality of clamping parts relative to the horizontal direction according to the calculated deviation, and further determines whether the calculated tilt angle of each of the plurality of clamping parts exceeds the second allowable value, When the calculation unit determines that at least one of the tilt angles of each of the plurality of chuck parts exceeds the second allowable value, the control unit stops the movement of the end effector. A conveying device as described in claim 1 or 2, wherein, the thickness data of the substrate is stored in the position data storage unit, the calculation unit calculates the vertical position of each of the clamping head parts based on the obtained moving distance data and the detection data, and further determines whether each of the plurality of clamping head parts clamps the substrate based on the database stored in the position data storage unit, the thickness data of the substrate and the calculated vertical position. The conveying device as described in claim 1 or 2, wherein, the end actuator has a clamping portion, and the clamping portion clamps the substrate in batches from the side when the plurality of clamping head portions each clamp the substrate, The control unit causes the clamping unit to clamp the substrate and maintain the substrate clamped by the clamping unit when all or part of the plurality of clamping units clamp the substrate, and causes the end effector to rise relative to the at least two first sensors by at least the distance when the lowest clamping unit is at the first reference position, or causes the end effector to descend relative to the at least two first sensors by at least the distance when the highest clamping unit is at the second reference position. The conveying device as described in claim 1 or 2 further includes: a base, which supports the end effector in a manner that enables it to move forward and backward; a first moving mechanism, which supports the base and is capable of moving in a direction perpendicular to the forward and backward direction and the up and down direction of the end effector; a support body, which supports the first moving mechanism in a manner that enables it to move; and a second sensor, which is disposed on the base and detects the inclination of the base in the forward and backward direction relative to the upper surface of the support body, when the output of the second sensor exceeds the third allowable value, the calculation unit determines that the inclination of the base in the forward and backward direction relative to the support body is abnormal, When the calculation unit determines that the tilt in the forward and backward direction is abnormal, the control unit stops the movement of the end effector. The conveying device as described in claim 9, wherein, the second sensor comprises: a light-emitting portion, disposed on the base, emitting light in the advancing and retreating direction; a light-receiving portion, disposed on the base, facing the light-emitting portion in the advancing and retreating direction and receiving light from the light-emitting portion, and measuring the amount of light received; and a light-shielding plate, disposed on the supporting body, extending from the supporting body to between the light-emitting portion and the light-receiving portion to block a portion of the light from the light-emitting portion, when the inclination of the base in the advancing and retreating direction relative to the supporting body changes, the position of the light-shielding plate relative to the light-emitting portion and the light-receiving portion changes, thereby changing the amount of light blocked from the light-emitting portion, When the change in the amount of light measured by the light receiving unit exceeds the third allowable value, the calculation unit determines that the inclination of the base relative to the advancing and retreating direction of the support body is abnormal. The conveying device as described in claim 1 or 2 further includes: A first motor drives a second moving mechanism, the second moving mechanism moves the end actuator forward and backward; and A second motor drives a third moving mechanism, the third moving mechanism moves the second moving mechanism up and down, The calculation unit obtains torque value data from the first motor and the second motor respectively, and determines whether the torque value of the first motor obtained exceeds the first threshold value, and further determines whether the torque value of the second motor obtained exceeds the second threshold value, When the calculation unit determines that the torque value of the first motor exceeds the first threshold value, the control unit stops the first motor, or when the calculation unit determines that the torque value of the second motor exceeds the second threshold value, the control unit stops the second motor. A control method for a conveying device, the conveying device comprising: an end actuator having a plurality of clamping heads arranged in the vertical direction and clamping substrates respectively; and at least two first sensors arranged at a distance less than half of the distance from the topmost clamping head located at the top to the bottommost clamping head located at the bottom of the plurality of clamping heads, on the sides of the plurality of clamping heads, detecting whether there are objects on the sides, the control method for the conveying device comprises the following steps: In the state where the lowermost clamping head is at the first reference position, the step of raising the end actuator relative to the at least two first sensors by at least the distance, the first reference position is lower than the lowermost first sensor among the at least two first sensors by the distance, or in the state where the uppermost clamping head is at the second reference position, the step of lowering the end actuator relative to the at least two first sensors by at least the distance, the second reference position is higher than the uppermost first sensor among the at least two first sensors by the distance; During the step of causing the end effector to rise or fall relative to the at least two first sensors, data of the movement distance of the end effector relative to the first reference position or the second reference position is obtained, and detection data is obtained from the at least two first sensors; Based on the obtained movement distance data and the detection data, the up-down position of each of the chuck parts is calculated, and then the deviation of each of the chuck parts from the normal up-down position is calculated based on a database storing data of the normal up-down position of each of the chuck parts and the calculated up-down positions, and whether each of the chuck parts is abnormal is determined based on the calculated deviation; and In the event that at least one of the plurality of chucks is abnormal, the step of stopping the movement of the end effector.