JPH11154697A - Substrate treating apparatus and method for measuring amount of backlash - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate treating apparatus by which the moving position of a movable part which moves for the treatment or the transport of substrates can be controlled with high degrees of accuracy, and to provide a method for measuring the amount of backlash. SOLUTION: A driving mechanism is provided with a stepping motor 1, a driving pulley 2 mounted on the axis of the motor, an idler pulley 3 and a timing belt 4 which is looped over between the driving pulley 2 and the idler pulley 3. A sector 6 for confirming position is mounted on the timing belt 4. A returning limit sensor 6 is disposed in the returning direction of the timing belt 4, and an advancing limit sensor 8 is disposed in the advancing direction. Prior to the operation of the driving mechanism, the stepping motor 1 is provided with the same number of driving pulses in both the forward and reverse directions. The difference between the moving amount in the advancing direction B of the timing belt 4 and that in the returning direction A is detected based on to the number of driving pulses of the stepping motor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a substrate processing apparatus having a movable portion driven for processing or transporting a substrate, and a method of measuring a backlash amount in a mechanism for driving the movable portion.

[0002]

2. Description of the Related Art Substrate processing apparatuses are used to perform various processes on substrates such as semiconductor wafers, glass substrates for liquid crystal display devices, glass substrates for photomasks, and glass substrates for optical disks. For example, in a semiconductor device manufacturing process, a substrate processing apparatus in which each of a series of processes is unitized and a plurality of processing units are integrated is used in order to increase production efficiency.

FIG. 5 is a perspective view of a substrate processing apparatus. The substrate processing apparatus has a processing area 20 and a loading / unloading area 30. In the processing region 20, a rotary coating unit 20a for applying a processing liquid to the substrate, a rotary developing unit 20b for performing a developing process on the substrate, a heating unit HP for performing a heating process on the substrate, and a cooling unit for performing a cooling process on the substrate An edge exposure unit (not shown) for performing exposure processing of the unit CP, an outer peripheral edge portion (edge) of the substrate, and the like are arranged. Further, a transfer area 21 is provided in the processing area, and a transfer unit 22 for transferring a substrate in the transfer area 21 is provided.

A loading / unloading area 30 has a loading section 32 for loading a plurality of cassettes 31 for accommodating a plurality of substrates.
Transfer robot 3 that can move in and out of loading / unloading area 30
3 are provided.

The transfer robot 22 in the transfer area 21 holds the substrate W and moves in the horizontal and vertical directions, and transfers the substrate to and from each processing unit. Further, the transfer robot 33 moves in the horizontal and vertical directions while holding the substrate W in the carry-in / carry-out area 30. Then, the transfer of the substrate between the cassette 31 and the transfer robot 32 is performed.

In order to perform the above-described moving operation, the transfer robot 22 and the transfer robot 33 are provided with movable parts for processing or transferring the substrate W. For example,
A movable unit such as a moving unit that horizontally moves the transfer robot 22 and the transfer robot as a whole, and a substrate holding arm that horizontally moves the substrate W while holding the substrate W is provided.

[0007] These movable parts are driven by a drive mechanism. The movable parts of the transfer robot 22 and the transfer robot 33 must accurately move to predetermined positions in the processing area 20 and the carry-in / carry-out area 30, respectively, in order to carry and transfer substrates. For this reason, the drive mechanism is provided with a position control system.

FIG. 6 is a schematic diagram showing the structure of a conventional driving mechanism. In FIG. 6, the driving mechanism is a stepping motor 1, a driving pulley 2 attached to a rotating shaft of the stepping motor 1, a driven pulley 3 attached to a rotating shaft 5, and a timing applied to the driving pulley 2 and the driven pulley 3. The belt 4 is provided. A plurality of teeth are formed on the outer peripheral surfaces of the driving pulley 2 and the driven pulley 3. Further, a plurality of teeth that mesh with the teeth of the driving pulley 2 and the driven pulley 3 are formed on the inner peripheral surface of the timing belt 4.

The driving mechanism shown in FIG.
Is transmitted to the timing belt 4 and the rotating shaft 5. Then, a driving force is applied to the movable parts of the transfer robot 22 and the transfer robot 33 that are connected to the rotating shaft 5 or directly connected to the timing belt 4 to move the movable parts to predetermined positions.

For example, when the movable parts of the transfer robot 22 and the transfer robot 33 are the substrate holding arms that hold the substrate and move forward and backward, the substrate holding arm receives the driving force from the timing belt 4 and enters the standby position. Reciprocate between the substrate and the substrate transfer position. When transferring a substrate, the substrate cannot be transferred to a processing unit or the like unless the substrate holding arm accurately moves to a predetermined substrate transfer position.

Therefore, the drive mechanism of FIG. 6 is provided with a position control system for controlling the position and the amount of movement of the timing belt 4. The position control system of the drive mechanism includes a position confirmation sector 6, a return limit sensor (RLS) 7, a feed limit sensor 8, an origin sensor (OS) 10, and a control unit 9. The position confirmation sector 6 is attached to the timing belt 4 and reciprocates as the timing belt 4 rotates. Hereinafter, the timing belt 4 indicated by an arrow A in the figure
Is referred to as the return direction, and the direction indicated by arrow B is referred to as the feed direction.

The turning operation of the timing belt 4 is controlled by changing the pulse number and pulse frequency of the driving pulse applied to the stepping motor 1. Also,
The return limit sensor 7 is used for detecting the position of the timing belt 4 in the return direction A, the origin sensor 10 is used for detecting the origin position, and the feed limit sensor 8 is used for detecting the position of the timing belt 4 in the feed direction B. .

FIG. 7 is an explanatory diagram of the driving operation of the driving mechanism of FIG. 6, and FIG. 8 is a flowchart of the driving operation of the driving mechanism. In the following description, the rotation direction of the stepping motor 1 that moves the timing belt 4 in the return direction A is defined as the reverse rotation direction, and the rotation direction that is moved in the feed direction B is defined as the normal rotation direction.

In the driving mechanism shown in FIG.
Theoretically, when the movable unit connected to the timing belt 4 is at the standby position (this is called a mechanical origin), the position confirmation sector 6 is detected by the origin sensor 10 (this is called the drive origin). It is arranged as in. However, in actuality, when assembling the driving mechanism, it is difficult to accurately arrange the origin sensor 10 at the driving origin, which causes misalignment. Therefore, at the time of assembling the drive mechanism, the amount of deviation between the mounting position of the origin sensor 10 and the driving origin position is measured in advance, and the origin correction amount d corresponding to this deviation amount is measured.
Is calculated, and a position correction for setting the timing belt 4 to the driving origin when the driving mechanism operates is performed. In addition,
In the following description, a case where the origin correction amount d is generated in the return direction A from the origin sensor 10 will be described.

As shown in FIGS. 7A and 8, when returning the timing belt 4 moved in the feed direction B to the driving origin position, the control unit 9 first rotates the stepping motor 1 in the reverse direction (step S21). . As a result, the timing belt 4 and the position confirmation sector 6 move in the return direction A.

The detection unit 7 of the return limit sensor 7
a detects the position confirmation sector 6 (step S2).
2) The control unit 9 rotates the stepping motor 1 forward (step S23). This causes the timing belt 4 and the position confirmation sector 6 to move in the feed direction B as shown in FIGS. 7B and 8.

When the detection section 10a of the origin sensor 10 detects the position confirmation sector 6 (step S24),
As shown in FIGS. 7C and 8, the control unit 9 gives the stepping motor 1 a reverse rotation driving pulse corresponding to the origin correction amount d calculated in advance, rotates the stepping motor 1 in the reverse direction, and returns the timing belt 4. Move in the direction A and stop at the drive origin position. As a result, the movable part connected to the timing belt 4 is stopped at the standby position (Step S25).

Thereafter, in order to move the movable section from the standby position to the position in the predetermined feeding direction B, the control section 9 rotates the stepping motor 1 forward to move the timing belt 4 in the feeding direction B, thereby moving the movable section. The part is moved to a predetermined position (step S26).

[0019]

However, in the conventional driving mechanism, the position control taking into account the backlash between the timing belt 4 and the driving pulley 2 is not performed. For this reason, when the rotation direction of the timing belt 4 changes, an error occurs in the movement amount of the timing belt 4 due to backlash.

Here, the backlash will be described.
FIG. 9 is an explanatory diagram of backlash.

As shown in FIG. 9 (a), the tooth profile of the pulley 11 and the timing belt 4 for transmitting power by meshing with each other is such that the tooth surfaces of the pulley 11 and the timing belt 4 smoothly mesh with each other. The tooth surfaces 11a and 11b of the pulley 11 and the tooth surfaces 4a and 4b of the timing belt 4
And a gap called a backlash is formed.

When the pulley 11 moves in the feed direction B, one tooth surface 11a of the pulley 11 and one tooth surface 4a of the timing belt 4 come into contact, and the driving force of the pulley 11 causes the timing belt 4 to feed. Move in direction B.

Further, as shown in FIG.
1 is reversed from the feed direction B to the return direction A, the timing belt 4 does not initially move, and the pulley 11
Only the tooth surface 11a of the pulley 11 starts moving in the return direction A, and the one tooth surface 11a of the pulley 11 is separated from the one tooth surface 4a of the timing belt 4. After the other tooth surface 11b of the pulley 11 abuts on the other tooth surface 4b of the timing belt 4, the driving force of the pulley 11 is transmitted to the timing belt 4, and the timing belt 4 moves in the return direction A.

As described above, when the moving direction of the pulley 11 is reversed, the moving distance of the timing belt 4 becomes smaller than the moving distance of the pulley 11 by the backlash amount e. In FIG. 9, the backlash between the linear pulley 11 and the timing belt 4 is described. However, the same is true between the driving pulley 2 and the timing belt 4 in the driving mechanism in FIG. 6. Occurs.

In the drive mechanism shown in FIG. 6, the amount of rotation of the stepping motor 1 is controlled by the number of applied drive pulses. The rotation amount of the driving pulley 2 corresponds to the rotation amount of the stepping motor 1. However, the movement amount when the movement direction of the timing belt 4 is reversed is reduced by the backlash amount between the driving pulley 2 and the timing belt 4. For this reason, the moving position of the movable part moved by the timing belt 4 is shifted by the backlash amount every time the reversing movement is performed.

In this case, when the moving amount of the driving pulley 2 corresponding to the rotation amount of one step of the stepping motor 1 is larger than the backlash amount, the reduction of the moving amount of the timing belt 4 due to the backlash does not cause a serious problem. However, when the movement amount of the drive pulley 2 corresponding to the rotation amount of one step of the stepping motor is smaller than the backlash amount, the movement error of the timing belt 4 cannot be ignored, and the movement of the movable portion is performed with high accuracy. Trouble occurs.

The effect of the backlash as described above is shown in FIG.
This occurs when the timing belt 4 shown in (c) is moved in the feed direction B from the drive origin position. That is, the timing belt 4 is stopped at the drive origin moved from the origin sensor 10 in the return direction A by the origin correction amount d. For this reason,
When the timing belt 4 is reversely moved from the driving origin in the feed direction B opposite to the return direction A, the timing belt 4 does not move in the feed direction B due to backlash at the initial stage of the movement. Therefore, the timing belt 4 moves to a position shifted by a backlash amount e from a desired position in the feed direction B.

The displacement due to the backlash occurs every time the moving direction of the timing belt 4 is reversed. For this reason, in the conventional drive mechanism, it is difficult to control the position of the movable part with high accuracy.

An object of the present invention is to provide a substrate processing apparatus capable of controlling a moving position of a movable portion for moving or processing a substrate with high accuracy.

Still another object of the present invention is to provide a method of measuring the amount of backlash for measuring the amount of backlash between a driving member and a moving member engaged with each other.

[0031]

Means for Solving the Problems and Effects of the Invention A substrate processing apparatus according to a first aspect of the present invention is a substrate processing apparatus having a movable portion that moves for processing or transporting a substrate. A moving member that is provided to be movable in a first direction and a second direction opposite to the first direction, and that moves the movable portion, and a second tooth that meshes with the first tooth; A driving member movably provided in a direction corresponding to the first and second directions to move the moving member in the first and second directions, a driving source for driving the driving member, and driving by the driving source Control means for controlling the movement of the member and correcting the movement amount of the drive member based on the backlash amount between the movement member and the drive member when the drive member is moved in one direction and then in the opposite direction. It is provided with.

In the substrate processing apparatus according to the first aspect of the present invention, a mechanism including a driving source, a driving member, and a moving member is used to drive the movable portion. The driving force generated from the driving source is transmitted to the driving member, and further transmitted to the moving member via teeth of the driving member and the moving member that mesh with each other.
Then, the movable part directly or indirectly connected to the moving member is moved to a predetermined position.

Each time the moving direction of the moving member is reversed, the control means corrects the moving amount of the driving member based on the amount of backlash between the driving member and the moving member. For this reason, even if the moving member is reversely moved, an error due to backlash in the moving amount of the moving member is prevented, and the position of the movable portion moved by the moving member can be controlled with high accuracy.

The substrate processing apparatus according to the second invention has a first
In the configuration of the substrate processing apparatus according to the present invention, the moving member is an endless belt provided with a plurality of first teeth and movably provided in the first and second directions.
Has a plurality of second teeth meshing with the teeth of the first endless belt
And a rotation member provided to be capable of normal rotation and reverse rotation to move the rotation member in the second direction, the driving source is rotation driving means for rotating the rotation member forward and reverse, and the control means is a rotation driving means. When controlling the rotation of the rotating member and rotating the rotating member in one of the normal rotation direction and the reverse rotation direction and then in the reverse direction, the first teeth of the endless belt and the second teeth of the rotation member are rotated. The rotation amount of the rotating member is corrected based on the backlash amount between the teeth.

In this case, there is usually a backlash between the teeth of the rotating member and the teeth of the endless belt, and the backlash moves between the rotating member and the endless belt each time the rotation driving means rotates forward and backward. A quantity error occurs. Therefore,
The controller corrects the amount of movement of the endless belt to a desired amount by correcting the amount of rotation of the rotating member based on the amount of backlash. Thereby, the position of the movable part moved by the endless belt can be controlled with high accuracy.

A substrate processing apparatus according to a third aspect of the present invention is the substrate processing apparatus according to the second aspect, wherein the rotating member comprises:
The endless belt is formed of a pulley having a plurality of first teeth on the outer periphery, and the endless belt is formed of a timing belt having a plurality of second teeth meshing with the first teeth of the pulley.

In this case, the amount of movement of the pulley is corrected based on the amount of backlash between the pulley and the timing belt engaged with the pulley. Therefore, even if the pulley is reversely moved, an error due to backlash in the movement amount of the timing belt is prevented, and the position of the movable portion moved by the timing belt can be controlled with high accuracy.

The substrate processing apparatus according to the fourth invention comprises:
In the configuration of the substrate processing apparatus according to any one of the third aspects of the present invention, the control unit may move the driving member in one direction by a predetermined moving amount in the first direction when the backlash amount is measured. The amount of backlash is detected based on the difference between the amount of movement of the moving member and the amount of movement of the moving member in the second direction when the driving member is moved in the reverse direction by a predetermined amount of movement.

In this case, when the driving member moves in one direction, the moving amounts of the driving member and the moving member are equal. However, when the driving member moves in the opposite direction, the backlash between the driving member and the moving member causes a displacement between the driving member and the moving member, and the amount of movement of the driving member and the moving member is reduced by the amount of backlash. There is a corresponding difference. Therefore, the control means detects the amount of backlash between the driving member and the moving member by detecting the difference between the amount of movement of the moving member in the first direction and the amount of movement in the second direction, and detects the amount of backlash between the driving member and the moving member. The moving amount of the driving member is corrected based on the amount. Thereby, the position of the movable part moved by the moving member can be controlled with high accuracy.

According to a fifth aspect of the present invention, in the substrate processing apparatus according to the fourth aspect of the present invention, there is provided a substrate processing apparatus according to the fourth aspect, further comprising: a detecting section provided on the moving member; Means for moving the driving member in one direction by the driving source from the state in which the detection means is detecting the portion to be detected at the time of measuring the backlash amount. The driving member is moved in the opposite direction by a predetermined moving amount, and when the driving member moves in one direction, the moving amount of the driving member from the start of the movement of the driving member until the detecting means no longer detects the detected portion. And detecting the amount of backlash based on the difference between the amount of movement of the drive member from when the detection unit detects the detected portion to when the drive member stops when the drive member moves in the opposite direction.

In this case, when the driving member is moved in one direction by a predetermined moving amount, the moving amount of the driving member from the start of the movement of the driving member until the detecting means stops detecting the portion to be detected is obtained. . When the driving member is moved in the reverse direction, the amount of movement of the driving member from when the detection unit detects the detected portion to when the driving member stops is obtained. A difference corresponding to the amount of backlash between the driving member and the moving member occurs between the obtained moving amount in one direction and the moving amount in the opposite direction. Therefore, the control means can detect the amount of backlash between the driving member and the moving member by detecting the difference between the moving amount of the driving member in one direction and the moving amount in the opposite direction. Then, the control means corrects the moving amount of the driving member based on the detected backlash amount, thereby controlling the position of the movable portion with high accuracy.

A substrate processing apparatus according to a sixth aspect of the present invention is the substrate processing apparatus according to the fourth or fifth aspect, wherein the driving source comprises a stepping motor, and the control means controls the pulse of the driving pulse applied to the stepping motor. The backlash amount is detected based on the number.

In this case, the stepping motor is capable of normal rotation and reverse rotation according to the drive pulse, and the amount of rotation is controlled by the number of drive pulses. Therefore, the control means detects the number of drive pulses to the stepping motor when the moving member is reversely moved,
The backlash amount can be accurately detected.

According to a seventh aspect of the present invention, in the configuration of the substrate processing apparatus according to the fourth or fifth aspect, the driving source comprises a servomotor, and the control means detects a rotation amount of the servomotor. It has an encoder and detects the amount of backlash based on the output from the encoder.

In this case, the amount of rotation of the servomotor is detected by the output from the encoder. For this reason, the control means can accurately detect the backlash amount based on the output from the encoder when the moving member is reversed.

According to an eighth aspect of the present invention, there is provided a method for measuring the amount of backlash, comprising: a moving member having first teeth and movably provided in a first direction and a second direction opposite to the first direction. And a second tooth meshing with the first tooth, the first and second teeth for moving the moving member in the first and second directions.
A measurement method for measuring the amount of backlash between a driving member movably provided in a direction corresponding to the direction of
The moving member is provided with a detected portion and a detecting means for detecting the detected portion is provided, and a moving amount of the moving member in the first direction when the driving member is moved by a predetermined moving amount in one direction. The amount of backlash is measured based on the difference between the amount of movement of the moving member in the second direction when the driving member is moved in the reverse direction by a predetermined amount of movement.

In the backlash measuring method according to the eighth aspect of the present invention, the detected portion is provided on the moving member, and the detecting means is provided at a predetermined position in the moving direction of the moving member. And
After moving the driving member in one direction, it is moved in the opposite direction by the same amount. When the moving member moves in one direction due to the movement of the driving member, the moving member and the driving member move by the same amount. Further, when the moving member moves in the opposite direction, the moving amount of the moving member is smaller than the moving amount of the driving member by the backlash amount between the moving member and the driving member. Therefore, the amount of movement of the detected part provided on the moving member in one direction and the amount of movement in the opposite direction are detected by the detecting means, and the difference is obtained to determine the distance between the driving member and the moving member. Can easily be measured.

According to a ninth aspect of the present invention, in the method of measuring the backlash amount according to the eighth aspect of the present invention, the driving member is moved in one direction from a state in which the detecting means is detecting the portion to be detected. After moving a predetermined amount,
The drive member is moved in the reverse direction by a predetermined movement amount, and when the drive member moves in one direction, the movement amount of the drive member from the start of the movement of the drive member until the detection means no longer detects the detected portion. Further, when the driving member moves in the reverse direction, the amount of backlash is measured based on the difference between the amount of movement of the driving member from when the detection unit detects the detected portion to when the driving member stops.

In this case, when the drive member is moved by a predetermined amount in one direction, the amount of movement of the drive member from the start of the movement of the drive member until the detection means stops detecting the portion to be detected is obtained. . When the driving member is moved in the reverse direction, the amount of movement of the driving member from when the detection unit detects the detected portion to when the driving member stops is obtained. A difference corresponding to the amount of backlash between the driving member and the moving member occurs between the obtained moving amount in one direction and the moving amount in the opposite direction. Therefore, by detecting the difference between the amount of movement of the driving member in one direction and the amount of movement in the opposite direction, the amount of backlash between the driving member and the moving member can be easily measured.

[0050]

FIG. 5 is a perspective view of a substrate processing apparatus. The substrate processing apparatus includes the processing area 20 and the loading / unloading area 3
Has zero. In the processing region 20, a rotary coating unit 20a for applying a processing liquid to the substrate, a rotary developing unit 20b for performing a developing process on the substrate, a heating unit HP for performing a heating process on the substrate, and a cooling unit for performing a cooling process on the substrate An edge exposure unit (not shown) for performing exposure processing of the unit CP, an outer peripheral edge portion (edge) of the substrate, and the like are arranged. Further, a transfer area 21 is provided in the processing area,
A transport unit 22 that transports a substrate in the transport area 21
Are provided in the transfer area 21.

The loading / unloading area 30 has a loading section 3 on which a plurality of cassettes 31 for storing a plurality of substrates W are placed.
2 and a transfer robot 33 that can move within the carry-in / carry-out area 30.

The transfer robot 22 in the transfer area holds the substrate W, moves in the horizontal and vertical directions, and transfers the substrate W to and from each processing unit. Further, the transfer robot 33 moves in the horizontal and vertical directions while holding the substrate W in the carry-in / carry-out area 30. Then, the transfer of the substrate between the cassette 31 and the transfer robot 32 is performed.

FIG. 1 is a schematic diagram showing a configuration of a driving mechanism of a substrate processing apparatus according to an embodiment of the present invention. The driving mechanism of FIG. 1 is a transfer robot 33 provided in the substrate processing apparatus of FIG.
Moving section of the transfer robot 22 and the substrate W
This is used for a substrate holding arm that moves in the horizontal direction while holding, or a movable portion such as a moving portion of an exposure optical system of an edge exposure unit (not shown).

In FIG. 1, the driving mechanism includes a stepping motor 1, a driving pulley 2 attached to a rotating shaft of the stepping motor, a driven pulley 3 attached to a rotatable rotating shaft 5, a driving pulley 2 and a driven pulley 3. A timing belt 4 is provided.

A plurality of teeth are formed on the outer peripheral surfaces of the driving pulley 2 and the driven pulley 3. Further, a plurality of teeth that mesh with the teeth of the driving pulley 2 and the driven pulley 3 are formed on the inner peripheral surface of the timing belt 4. When the stepping motor 1 rotates, the drive pulley 2 rotates. Tooth of drive pulley 2 and driven pulley 3 and timing belt 4
Teeth are in mesh with each other. Therefore, the rotational force of the driving pulley 2 is transmitted to the driven pulley 3, and the driving pulley 2 and the driven pulley 3 rotate in synchronization.

The driving mechanism shown in FIG.
Is transmitted to the timing belt 4 and the rotating shaft 5. Then, a driving force is applied to the movable portion of the transfer robot or the transfer robot that is connected to the rotating shaft 5 or directly connected to the timing belt 4 to move the movable portion to a predetermined position.

Therefore, the drive mechanism of FIG. 1 uses a timing belt 4 to accurately move the movable portion to a predetermined position.
Has a position control system for controlling the position and the amount of movement. The position control system includes a position confirmation sector 6, a return limit sensor 7, a feed limit sensor 8, and a control unit 9.

The sector 6 for position confirmation is the timing belt 4
And reciprocates with the rotation of the timing belt 4. Hereinafter, the moving direction of the timing belt 4 indicated by the arrow A in the drawing is referred to as the return direction, and the direction indicated by the arrow B is referred to as the feed direction.

The rotation of the timing belt 4 is controlled by changing the number of drive pulses and the pulse frequency applied to the stepping motor 1.

The control section 9 receives the outputs of the return limit sensor 7 and the feed limit sensor 8 and controls the number of drive pulses applied to the stepping motor 1 and the pulse frequency to control the rotation operation of the stepping motor 1.

Here, the stepping motor 1 of the present embodiment
Corresponds to the driving source and the rotation driving means of the present invention, the driving pulley 2 corresponds to the driving member and the rotating member, the timing belt 4 corresponds to the moving member and the endless belt, and the control unit 9 corresponds to the control means. Further, the position confirmation sector 6 corresponds to a detected portion, and the return limit sensor 7 corresponds to a detecting means.

The drive mechanism of this embodiment detects the amount of backlash between the drive pulley 2 and the timing belt 4, and performs an operation taking into account the amount of backlash during driving. FIG. 2 is an explanatory diagram of the driving operation of the driving mechanism of the present embodiment, and FIG. 3 is a flowchart of the driving operation. In the following description, the rotation direction of the stepping motor 1 that moves the timing belt 4 in the return direction A is referred to as the reverse rotation direction, and the rotation direction that moves the timing belt 4 in the feed direction B is the normal rotation direction.

First, as shown in FIGS. 2A and 3, the control section 9 rotates the stepping motor 1 in the reverse direction and moves the timing belt 4 in the return direction A (Step S).
1). Then, when the detection unit 7a of the return limit sensor (RLS) 7 detects the position confirmation sector 6 (Step S).
2) The control unit 9 further applies a predetermined number of drive pulses in the return direction A to the stepping motor 1 in the return direction A from the position where the detection unit 7a of the return limit sensor 7 has detected the position confirmation sector 6, and moves the timing belt 4 in the return direction A. And the position confirmation sector 6 is stopped at the maximum return position Pb. The maximum return position Pb is set to a position where a part of the position confirmation sector 6 is detected by the detection unit 7a of the return limit sensor 7 (Step S3).

Further, as shown in FIG. 2B and FIG. 3, the control section 9 supplies several stepping drive pulses to the stepping motor 1 to cause the stepping motor 1 to rotate forward and then stop. As a result, the timing belt 4 stops at the position where the position confirmation sector 6 has moved by the distance B1 in the feed direction B from the maximum return position Pb. This position is set as the drive origin O. By setting the drive origin O on the feed direction B side from the maximum return position Pb, a movement error in the feed direction B due to banklash is not caused when the timing belt 4 is moved in the feed direction B thereafter. (Step S4).

Next, it is determined whether or not the backlash amount is detected (step S5). The operation of detecting the backlash amount is performed in the assembly stage of the substrate processing apparatus, and is not performed in the actual use stage. Therefore, here, the operation of detecting the backlash amount at the time of assembling the substrate processing apparatus will be described first. FIG. 4 is a waveform diagram of a drive pulse applied to the stepping motor.

As shown in FIG. 2C, FIG. 3 and FIG. 4A, when the backlash amount is detected (step S
5) The control unit 9 gives the stepping motor 1 a predetermined number (for example, 100 pulses) of forward drive pulses NF to move the timing belt 4 in the feed direction B, and moves the position confirmation sector 6 to the reverse position in the feed direction B. Stop at Pf.

At this time, as shown in FIG. 4A, the moving distance of the timing belt 4 in the feed direction B corresponding to the normal rotation drive pulse NF is Xf. The number of forward rotation drive pulses while the detection unit 7a of the return limit sensor 7 is detecting the position confirmation sector 6 is Nf, and the movement distance of the timing belt 4 during this period is Lf. The control section 9 counts the number Nf of forward rotation drive pulses while the detection section 7a of the return limit sensor 7 detects the sector 6 for position confirmation.

Next, FIGS. 2 (d), 3 and 4 (b)
As shown in (1), the control unit 9 gives the stepping motor 1 a reverse drive pulse NB having the same number of pulses as the forward drive pulse NF, moves the timing belt 4 in the return direction A, and then stops. Sector 6 for position confirmation at this time
Is the return origin Ob. The moving distance of the position confirmation sector 6 in the return direction A is defined as Xb, and the movement distance from the start of detection of the position confirmation sector 6 by the detection unit 7a of the return limit sensor 7 to the return origin Ob is Lb.
And The control unit 9 counts the number Nb of reverse rotation drive pulses from the start of the detection of the position confirmation sector 6 by the detection unit 7a of the return limit sensor 7 to the return origin Ob (step S6).

At the beginning of the reversing movement in the return direction A, a displacement occurs due to backlash between the timing belt 4 and the driving pulley 2. Therefore, the movement distance Lb of the position confirmation sector 6 in the return direction A is smaller than the movement distance Lf in the feed direction B by the backlash amount e. Therefore, the backlash amount e is obtained from the backlash amount e = Lf−Lb. The backlash amount e is determined by the controller 9
Is calculated by the counted number of drive pulses to the stepping motor 1 counted. That is, (Nf-Nb) is calculated as the backlash correction pulse Ne (step S
7).

When the backlash amount is detected, the control unit 9
Gives a forward drive pulse to the stepping motor 1 to move the position confirmation sector 6 further in the feed direction B of the return limit sensor 7 (step S8). Then, the process returns to the operations of steps S1 to S4 again, and stops the timing belt 4 at the driving origin position. Thereby, an actual driving operation of the driving mechanism is enabled.

During the operation of the driving mechanism, the operations of steps S6 to S8 are not performed in step S5, and the timing belt 4 is driven to a predetermined position in the feeding direction B from the driving origin. Further, when the timing belt 4 is reversed, the control unit 9 performs a correction by adding the already calculated backlash correction pulse Ne to a drive pulse corresponding to the actual moving distance of the timing belt 4 to be reversed and moves. 1 is driven (step S9).

As described above, in the above-described drive mechanism, the backlash amount can be obtained only by one return limit sensor 7 without using the origin sensor. For this reason,
The configuration of the position control system is simplified. Also, by adding a backlash correction pulse Ne to the drive pulse applied to the stepping motor 1 every time the rotation direction of the timing belt 4 is reversed, the movement amount of the timing belt 4 is controlled to be exactly the desired movement amount. can do. For this reason, the position of the movable part moved by the timing belt 4 can be controlled with high accuracy.

Further, before the actual use operation of the drive mechanism,
Since the backlash amount can be detected, the tension (tension) of the timing belt 4 is increased and the drive pulley 2
Adjustment work such as suppressing slippage between the belt and the timing belt 4 becomes unnecessary. Furthermore, since the origin sensor is omitted, there is no need to adjust the position of the origin sensor. As a result, man-hours for assembling the drive mechanism are reduced.

It should be noted that, instead of the stepping motor 1 of the drive mechanism of the above-described embodiment, a servomotor provided with an encoder may be used. In this case, the rotation amount of the servomotor is detected by the encoder, and the backlash amount can be calculated using the output signal from the encoder.

The drive mechanism according to the present embodiment can be applied not only to a transfer robot or a transfer robot of a substrate processing apparatus or an edge exposure unit, but also to other movable parts.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating a configuration of a driving mechanism of a substrate processing apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a driving operation of a driving mechanism.

FIG. 3 is a flowchart of a driving operation of a driving mechanism.

FIG. 4 is a waveform diagram of a driving pulse applied to a stepping motor.

FIG. 5 is a perspective view of the substrate processing apparatus.

FIG. 6 is a schematic diagram showing a configuration of a conventional driving mechanism.

FIG. 7 is an explanatory diagram of a driving operation of the driving mechanism of FIG. 6;

FIG. 8 is a flowchart of a driving operation of the driving mechanism.

FIG. 9 is an explanatory diagram of backlash.

[Explanation of symbols]

 Reference Signs List 1 stepping motor 2 drive pulley 3 driven pulley 4 timing belt 6 position confirmation sector 7 return limit sensor 9 control unit

Claims (9)

[Claims] 1. A substrate processing apparatus having a movable part that moves for processing or transporting a substrate, the substrate processing apparatus having a first tooth, and a second direction opposite to the first direction and the first direction. And a second member meshing with the first tooth, the second member meshing with the first tooth, for moving the moving member in the first and second directions. A driving member movably provided in directions corresponding to the first and second directions, a driving source for driving the driving member, and controlling the movement of the driving member by the driving source, and When moving the member in one direction after moving the member in one direction, the control unit corrects the amount of movement of the driving member based on the amount of backlash between the moving member and the driving member. Characteristic substrate processing equipment. 2. The moving member is an endless belt having a plurality of the first teeth and movably provided in the first and second directions. The driving member includes a first tooth. A rotating member having a plurality of the second teeth meshing with each other, the rotatable member being provided so as to be able to rotate forward and backward to move the endless belt in the first and second directions; Rotation driving means for rotating the member forward and backward, wherein the control means controls the rotation of the rotation member by the rotation driving means, and rotates the rotation member in one of a forward rotation direction and a reverse rotation direction. When rotating in the reverse direction after the rotation, the amount of rotation of the rotating member is corrected based on the amount of backlash between the first teeth of the endless belt and the second teeth of the rotating member. Claim 1. Substrate processing equipment. 3. The rotating member includes a pulley having a plurality of the first teeth on an outer periphery thereof, and the endless belt includes a timing belt having a plurality of the second teeth meshing with the first teeth of the pulley. 3. The substrate processing apparatus according to claim 2, wherein: 4. The method according to claim 1, wherein, when measuring the backlash amount, the control unit moves the moving member in the first direction when the driving member is moved by a predetermined moving amount in one direction;
The backlash amount is detected based on a difference between the moving amount of the moving member in the second direction when the driving member is moved in the reverse direction by the predetermined moving amount. The substrate processing apparatus according to any one of claims 1 to 3. 5. The apparatus according to claim 5, further comprising: a detection unit provided on the moving member; and a detection unit configured to detect the detection unit moving with the moving member, wherein the control unit performs the measurement when measuring the backlash amount. After the detecting means detects the detected part, the driving source moves the driving member by one predetermined amount in one direction, and then the driving source moves the driving member in the reverse direction by the predetermined movement. An amount of movement of the drive member from the start of movement of the drive member when the drive member moves in the one direction from the start of movement of the drive member until the detection unit no longer detects the detected portion; Detecting the amount of backlash based on a difference between the amount of movement of the driving member from when the detection unit detects the detected portion to when the driving member stops when the member moves in the reverse direction; Especially The substrate processing apparatus according to claim 4,. 6. The method according to claim 4, wherein the driving source comprises a stepping motor, and the control means detects the backlash amount based on the number of driving pulses applied to the stepping motor. Substrate processing equipment. 7. The drive source includes a servomotor, the control unit includes an encoder that detects a rotation amount of the servomotor, and detects the backlash amount based on an output from the encoder. The substrate processing apparatus according to claim 4 or 5, wherein 8. A moving member having first teeth and movably provided in a first direction and a second direction opposite to the first direction, and a moving member meshing with the first teeth. Backlash between a driving member having two teeth and movably provided in directions corresponding to the first and second directions to move the moving member in the first and second directions. A measuring method for measuring an amount, comprising: providing a detected portion on the moving member and providing a detecting means for detecting the detected portion, wherein the driving member is moved by a predetermined moving amount in one direction. Difference between the moving amount of the moving member in the first direction and the moving amount of the moving member in the second direction when the driving member is moved in the reverse direction by the predetermined moving amount. Measuring the backlash amount based on the backlash amount Measurement method. 9. After moving the driving member in one direction by a predetermined amount of movement from a state in which the detecting means is detecting the detected portion, move the driving member in the opposite direction by the predetermined amount of movement. Moving the drive member when the drive member moves in the one direction from the start of the movement of the drive member until the detection unit no longer detects the detected part; Wherein the backlash is measured based on a difference between the movement of the driving member from when the detection unit detects the detected portion to when the driving member stops when the movement in the reverse direction is performed. The method for measuring a backlash amount according to claim 8.