JP2003340754A - Articulated robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an area exclusively required for the orientation, i.e., the direction of a work so that arms face both sides of the work in a non-contact manner. <P>SOLUTION: In an articulated robot 1 in which a first arm 3 and a second arm 4 are rotatably connected to a hand part 6 of a rotary table or the like to hold a work 5 such as a wafer, the work 5 at a first position of a cassette or the like is taken out by the hand part 6, and temporarily placed at a temporary placement position, the work 5 is re-taken by the hand part 6, and installed on the second position 10 of a process device or the like, a sensor 25 to detect a part 5a to be detected such as a notch formed in the work 5 is provided in an area of rotation of the work 5 by the first arm 3 and the second arm 4, and a temporary placement hand part 26 forming the temporary placement position is integrated with a base. The part 5a to be detected is detected by the sensor 25 while rotating the work 5 by the first arm 3 and the second arm 4 while the work 5 is held by the hand part 6, the holding angle θe of the work 5 is detected, and the work 5 is temporarily placed on the temporary placement hand part 26 at a predetermined angle based on the holding angle θe. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an articulated robot for moving a work. More specifically, the present invention relates to a mechanism for orienting, that is, orientation of a work of an articulated robot.

[0002]

2. Description of the Related Art An articulated robot is used to move a work such as a semiconductor wafer between process devices such as a cassette and a film forming device. The articulated robot 100 is
For example, as shown in FIG. 21, the base 101 and the first arm 10
2, the second arm 103, and the hand unit 104. Then, when the wafer 107 is transferred from the cassette 105 to the process device 106, a so-called orientation work for adjusting the orientation and holding angle of the wafer 107 may be performed. The orientation is performed by the orientator 108. The Orientator 108
It has a vertical support cylinder 110 that rotates with respect to the base 109 and an optical sensor 111 that detects a notch (notch) 107a at the edge of the wafer 107 placed on the support cylinder 110.

When the wafer 107 is transferred from the cassette 105 to the process device 106, the hand portion 104 is inserted into the cassette 105 and the wafer 107 is pulled out.
Next, the arms 102 and 103 are rotated to rotate the wafer 1
The center of 07 is placed on the support cylinder 110 of the orientator 108. The support cylinder 110 sucks the wafer 107 and rotates as it is. Then, the sensor 111 of the orientator 108 has a notch 107a formed on the edge of the wafer 107.
To detect. Based on the detection result, the wafer 107 is supported by the orientator 108 in a predetermined direction.

Thereafter, the hand unit 104 lifts the wafer 107 of the orientator 108, and the process unit 10
Place on 6. Here, by supporting the wafer 107 in advance in a predetermined direction with respect to the orientator 108, the wafer 107 can be mounted in a predetermined direction with respect to the process apparatus 106.

[0005]

However, since the above-mentioned orientator 108 shown in FIG. 21 is separately and independently installed from the articulated robot 100, the cassette 105, and the process device 106, the wafer 107 is provided.
A large floor area is required to move the cassette 105 from the cassette 105 to the process device 106 via the orientator 108. In particular, since the orientator 108 needs to have an area equal to that of the wafer 107, the size of the orientator 108 has increased with the recent enlargement of the wafer 107 and the required floor area also increases. And the wafer 10
Since the movement of 7 is performed in the clean room, it is necessary to prepare a clean room as large as the size of the orientator 108, and it is difficult to reduce the equipment cost by reducing the work space.

Further, the support shaft 11 of the orientator 108
Since 0 supports the wafer 107 from the back side,
It must directly contact the backside of the wafer 107. However, if the back surface of the wafer 107 whose both surfaces are polished comes into contact with the back surface of the wafer 107, that portion may not be commercialized. Therefore, it has been desired to carry out orientation without contacting both surfaces of the wafer 107.

Therefore, the present invention is to provide an articulated robot which can reduce the area exclusively required for orientation and can perform orientation without touching any surface of the work. To aim.

[0008]

In order to achieve such an object, the invention of claim 1 is such that a second arm is rotatably connected to a first arm rotatable with respect to a base, and a tip of the second arm. Has a hand part that can hold a work, and
In the articulated robot in which the workpiece at the position is taken out by the hand unit, temporarily placed at the temporary placement position, the workpiece at the temporary placement position is again picked up by the hand unit, and the workpiece is placed at the second position. A sensor for detecting the detection unit is provided in the rotation range of the work by the first arm and the second arm, and a temporary placement hand unit for sandwiching and holding the work at the temporary placement position is provided integrally with the base, and the hand unit While the work is being held by the first arm and the second arm while rotating the work, the sensor detects the detected part and detects the holding angle of the work. The work is rotated and positioned by the first arm and the second arm so that the work should be positioned at the position where So as to lifting, it noted with and the first arm is a rotating table, the second arm so that an arm mechanism connecting the two arm members.

Therefore, since the sensor for detecting the detected portion of the work is provided in the rotation range of the work rotated by the first arm and the second arm, the work can be rotated right above the articulated robot. The orientation and holding angle of can be detected. Further, since the temporary placement hand unit is provided on the base of the articulated robot, the workpiece is placed at the temporary placement position at a predetermined angle, the hand unit is temporarily removed, and the hand unit is rotated by a predetermined angle to re-hold the workpiece. The work can be performed without using a dedicated device separately installed in addition to the articulated robot.

Further, the rotation of the workpiece for detecting the detected portion is performed while the workpiece is held by the hand portion, and the temporary placement position of the workpiece is the temporary placement hand portion. Therefore, other members do not come into contact with both surfaces of the work during orientation of the work.

Further, since the second arm is an extendable and retractable arm as a whole, even when the rotation center of the first arm and the rotation center of the work held by the hand portion are deviated from each other, the second arm is extended and contracted while the second arm is extended and retracted. By rotating one arm, the work can be rotated without eccentricity so that the rotation center of the first arm and the rotation center of the work coincide with each other. As a result, the edge of the disk-shaped work passes through the fixed point, so that only one sensor for detecting the detected portion is required.

Further, in the articulated robot according to claim 2,
The turntable is rotatably held on the base, and the sensor and the temporary placement hand unit are attached to the base. Therefore, since the base, the rotary table, the sensor, and the temporary placement hand unit can be integrated, the wafer orientation can be performed without disposing a dedicated orientation mechanism.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the present invention will be described below in detail based on an example of an embodiment shown in the drawings. As shown in FIGS. 1 and 4, the articulated robot 1 according to the present invention includes a first arm 3 rotatable with respect to a base 2 and a second arm 4 rotatably connected to the second arm 4. A hand portion 6 capable of holding a circular wafer 5 as a work is provided at the tip, and the wafer 5 at the first position is taken out by the hand portion 6 and temporarily placed at the temporary placement position. Is again picked up by the hand unit 6 and installed at the second position. And this articulated robot 1
Is provided with a sensor 25 for detecting a notch 5a, which is a detected portion formed on the wafer 5, in the rotation range of the wafer 5 by the first arm 3 and the second arm 4, and
The temporary placement hand parts 26, 26, which are the temporary placement positions of the base 2,
It is integrated with. In addition, this articulated robot 1
The holding angle θ of the wafer 5 is detected by detecting the notch 5a by the sensor 25 while rotating the wafer 5 by the first arm 3 and the second arm 4 while holding the wafer 5 in the hand portion 6.
e is detected, and the wafer 5 is temporarily placed on the temporary placement hand parts 26, 26 at a predetermined angle based on the holding angle θe.

The structure of the base 2, the first arm 3, the second arm 4, and the hand portion 6 of the articulated robot 1 of this embodiment is as follows.
The scalar type shown in FIGS. 2 and 3, the sensor 25 and the temporary placement hand parts 26, 26 according to the present invention are omitted, but this is because only the rotating parts of the arms 3, 4 and the like are shown. The configuration of the articulated robot 1 shown in 2 and 3 alone does not constitute the present invention.

As shown in FIGS. 2 to 4, the second arm 4 includes a base side arm 7 and a hand side arm 8 that are rotatably connected to each other and have the same length. I am trying to expand and contract while facing. A pulley 7 is attached to each of the base side arm 7 and the hand side arm 8.
a, 7b, 8a, 8b and belts 7c, 8c are built in. The diameter ratio between the base-side pulley 7a and the hand-side pulley 7b of the base-side arm 7 is 2: 1. The diameter ratio between the base-side pulley 8a and the hand-side pulley 8b of the hand-side arm 8 is 1: 2. Further, the base side arm 7 and the hand side arm 8 are connected by a connecting shaft 9. Here, the hand side pulley 7 of the base side arm 7
b and the arm 8 on the hand side are connected by a connecting shaft 9a. The base side arm 7 and the base side pulley 8a of the hand side arm 8 are connected by a connecting shaft 9b. Therefore, the base side pulley 7a and the hand side pulley 7b of the base side arm 7 (that is, the base side pulley 8 of the hand side arm 8).
The rotation angle ratio between a) and the hand side pulley 8b of the hand side arm 8 is 1: 2: 1.

A hand portion 6 is attached to the hand side pulley 8b of the hand side arm 8. Hand part 6
Is provided with, for example, two parallel support frames 6a, 6a. Therefore, by rotating the base-side pulley 7a of the base-side arm 7, the angle between the base-side arm 7 and the hand-side arm 8 changes, and the hand portion 6 moves toward the base-side of the base-side arm 7. Pulley 7a and hand side arm 8
And moves on a straight line connecting the hand side pulley 8b. At this time, the hand unit 6 moves while keeping the direction constant.

Here, the support frame 6a of the hand portion 6,
The orientation of the hand portion 6 is set so that the orientation of 6a is parallel to the straight line on which the hand portion 6 moves. This allows
When the hand portion 6 moves linearly, the support frame 6a,
Process device 1 such as a film deposition device for mounting wafer 5 on 6a
It can be moved while facing straight to 0 or a cassette.

On the other hand, the end portion of the base side arm 7 on the base side is attached to the first arm 3 by an elevating cylinder 11 so as to be able to move up and down. In this embodiment, the first arm 3 is a rotary table 3 having a substantially cylindrical shape. And the elevating cylinder 1
1 is provided at a position deviated from the center on the rotary table 3. As shown in FIG. 2, the rotary table 3 is rotatably supported by the base 2 by a bearing (not shown). A table rotation motor 12 is installed on the base 2. The table rotation motor 12 is connected to the rotation table 3 by a timing belt 13. For this reason,
The rotary table 3 is rotated by driving the table rotary motor 12.

A second arm lifting mechanism 14, a second arm extension / contraction mechanism 15, and a second arm rotation mechanism 16 are provided inside the rotary table 3. The second arm lifting mechanism 14 includes a guide shaft 17 having a vertical direction in the vertical direction,
It is fixed to the base side arm 7 with a slide plate 18 as an up-and-down moving part that is guided by the guide shaft 17 and is vertically movable, a screw shaft (not shown) as up-and-down driving means, and a lifting motor 19. It is provided with a cylindrical lifting cylinder 11 that moves up and down together with the slide plate 18. The screw shaft is screwed onto a part of the slide plate 18 and rotates to move the slide plate 18 up and down. Then, the screw shaft is rotated by the lifting motor 19. Therefore, the lifting motor 1
The screw shaft is rotated by the driving of the slide plate 18
When is moved up and down along the guide shaft 17, the lifting cylinder 11 is also moved up and down. The second arm 4 is moved up and down by moving up and down the elevating cylinder 11.

The second arm extension / contraction mechanism 15 includes the slide plate 1.
Timing belt 2 for connecting the arm rotation motor 20, the lifting cylinder 11 and the arm extension motor 20 installed on
1 and. When the arm extension motor 20 is driven, the elevating cylinder 11 is rotated to rotate the base-side arm 7, and the timing belt 7c is rotated along with the rotation of the base-side arm 7.
As a result, the pulley 7b rotates the hand side arm 8 (twice the rotation angle of the base side arm 7).
The bending angle of changes and it expands and contracts as a whole.

The second arm rotating mechanism 16 includes a pulley shaft 22 integrated with a base pulley 7a of the base arm 7, and a pulley shaft 22.
A hand side arm rotation motor 23 installed on the slide plate 18 and a timing belt 24 connecting the pulley shaft 22 and the hand side arm rotation motor 23 are provided.
The second arm 4 is rotated by driving the arm extending / contracting motor 20, and the motor 23 is driven in the direction opposite to the direction in which the arm 8 is extended / contracted (specifically, the pulleys 21 and 24 are moved in the same direction and at the same movement angle). Then, the second arm 4 rotates.

On the other hand, as shown in FIGS. 1 and 4 to 10,
Two support columns 27, 27 reaching the upper side of the rotary table 3 are attached to the base 2 on opposite sides of each other.
Temporarily placed hand parts 26, 2 are provided on top of the support columns 27, 27.
6 is attached. Therefore, each support pillar 27, 2
7, the temporary placement hand parts 26, 26 face each other, and the wafer 5
It can be sandwiched and held. Here, the temporary placement hand parts 26, 26 are provided above the lowermost positions of the rotary table 3 and the second arm 4. For this reason,
During the orientation of the wafer 5, the wafer 5 can always be positioned above the turntable 3 and the second arm 4. Thereby, the rotary table 3 and the second arm 4
Even if dust is dropped from the arms 3 and 4 by the operation such as rotation or sliding of the wafer 3, it does not hit the wafer 5. Therefore, the production yield of the wafer 5 can be improved.

Further, at the upper part of the support column 27 which supports one temporary placing hand portion 26, the sensor 25 is located at a position slightly closer to the center of the rotary table 3 than the temporary placing hand portion 26.
Is provided. As shown in FIGS. 11 and 12, the sensor 25 includes an LED 28 that emits detection light, a photodiode 29 that detects reflected light of the emitted light, and L
The ED 28 and the photodiode 29 are provided with optical path tubes 30 and 30 for guiding the light rays entering and exiting the wafer 5. Therefore, when the detection light of the LED 28 irradiates the edge portion of the wafer 5 held by the hand portion 6 and is reflected by the edge portion as shown in FIG. 11, the reflected light is incident on the photodiode 29, and FIG. As shown, when the light does not pass through the notch 5a and is not reflected, the light is not incident on the photodiode 29. Thereby, the position of the notch 5a can be detected.

A wafer 5 is produced by the articulated robot 1 described above.
From the cassette at the first position for orientation, and then the process device 10 at the second position.
The operation of placing the device on the board will be described.

As shown in FIGS. 2 to 4, in order to move the hand portion 6 to the position of the cassette, the table rotation motor 12 is used.
Drive the rotary table 3 to rotate the second arm 4
And, the hand unit 6 is entirely rotated. Then, the elevating cylinder 11 is rotated by driving the motors 20 and 23 to determine the orientation of the second arm 4. Furthermore, the arm extension motor 20
The angle between the base-side arm 7 and the hand-side arm 8 is changed by driving the second arm 4 to expand and contract. On the other hand, the elevating motor 19 is driven to move the elevating cylinder 11 up and down to set the vertical positions of the second arm 4 and the hand portion 6.

Then, the second arm 4 is extended, and the second arm 4 shown in FIG.
Insert the hand unit 6 into the cassette as shown in FIG. Here, the wafer 5 is taken out by hooking the wafer 5 on the tips of the support frames 6a, 6a and shortening the second arm 4. Further, the first arm 3 and the second arm 4 are moved with the wafer 5 placed on the hand section 6.

Here, as shown in FIGS. 1A and 5, a position where the edge portion of the wafer 5 can be detected by the sensor 25 and the wafer 5 can be held by the temporary placing hand portions 26, 26, that is, The wafer 5 is moved to the rotation area of the wafer 5. Then, the wafer 5 is rotated. Since the center of the wafer 5 and the center of the rotary table 3 are deviated from each other, the rotation of the wafer 5 is eccentric even if the rotary table 3 is simply rotated. Therefore, the wafer 5 is rotated so as not to be eccentric by expanding and contracting the second arm simultaneously with the rotation of the rotary table 3. While the wafer 5 is rotating, the sensor 25 detects the edge of the wafer 5.

When the wafer 5 is rotated and the notch 5a is detected by the sensor 25 as shown in FIGS. 1B and 6, when the wafer 5 is transferred onto the rotary table 3, that is, as shown in FIG. The angle difference between the position of the notch 5a in the state of 1 (A) and the position of the notch 5a when the notch 5a is detected by the sensor 25, that is, in the state of FIG. In other words, θe is a holding angle, that is, an angle formed by the insertion direction when the hand portion 6 is moved to the upper side of the rotary table 3 and the direction in which the notch 5a is formed.

Then, the direction in which the hand section 6 should be sent out to the process apparatus 10, that is, the reference direction S of the hand section 6
The angle formed by the direction with the notch 5a is set in advance as θt. This is because when the wafer 5 is accurately placed on the process device 10, the notch 5 is formed as shown in FIG.
It is set with reference to the angle at which a should be located. Next, the difference θa between the holding angles θe and θt is calculated. That is, this θa is the angle at which the hand portion 6 and the wafer 5 should be displaced, that is, the temporary placement angle. After the temporary placement angle θa is calculated, as shown in FIGS. 1C and 7, the hand unit 6 is positioned at a position displaced from the reference direction S toward the process device 10 by the temporary placement angle θa.

In this state, the wafer 5 is held by the temporary placement hand parts 26, 26 as shown in FIG. Then, the hand portion 6 is rotated by the temporary placement angle θa, and is oriented in the reference direction S with respect to the process device 10 as shown in FIGS. Further, the holding by the temporary placement hand units 26, 26 is released, and the wafer 5 is held again by the hand unit 6. As a result, the deviation of the temporary placement angle θa between the hand portion 6 and the wafer 5 is corrected and the orientation is completed.

Then, as shown in FIGS. 1E and 10, the hand portion 6 is moved to the position of the process device 10,
The second arm 4 is extended and inserted into the inside. At this time, the notch 5a of the wafer 5 due to the insertion of the hand portion 6
The place where is located becomes appropriate. As a result, the wafer 5 can be accurately faced to the process device 10. When the wafer 5 is placed on the process device 10, only the hand portion 6 is pulled out. This allows the wafer 5
Is completed.

By the way, in the embodiment described above, FIG.
The temporary placement angle θa is calculated from the holding angle θe obtained in the state shown in (B) and the known θt, and the hand portion 6 is moved to a position displaced from the reference direction S by θa as shown in FIG. 1 (C). However, if θa is too large, the connecting portion between the hand portion 6 and the hand-side arm 8 is temporarily placed in the hand portions 26, 2.
6 may interfere with the rotation and prevent rotation.

For example, in the multi-joint robot 1 shown in FIGS. 13 and 14, as shown in FIGS.
It is about 180 degrees until the notch 5a is detected after being installed in the rotation range on the rotary table 3 and further rotated by 90 degrees in order to install it in the process apparatus 10 shown in FIG. If you need to
3 (C), the hand portion 6 and the hand side arm 8
The connecting portion of the above will abut on the temporary placement hand section 26.

Therefore, as shown in FIG. 13C, the wafer 5 is rotated until just before the connecting portion of the hand portion 6 and the arm 8 on the hand side and the temporary placement hand portion 26 come into contact with each other, and at that time, the wafer 5 is rotated. The temporary placement hand parts 26, 26 are made to hold. At this time, the remaining angle θr is generated between the reference direction S which should be originally rotated. Then, as shown in FIG. 13D, the hand portion 6 is positioned so as to be displaced from the reference direction S by the remaining angle θr, and the wafer 5 is held again. Further, while holding the wafer 5, the wafer 5 is rotated by the remaining angle θr and directed toward the reference direction S as shown in FIG. This completes the orientation. Then, as shown in FIG. 14, the wafer 5 is placed on the process device 10.

According to the articulated robot 1 of this embodiment,
Hand unit 6 during rotation of wafer 5 during orientation
And the connecting portion of the hand side arm 8 and the temporary placement hand unit 26
Even if they are likely to come into contact with each other, the rotation of the wafer 5 can be stopped and the wafer 5 can be remounted by shifting the remaining angle θr, so that the orientation of the wafer 5 at 360 degrees can be performed. That is, the hand unit 6
Orientation of 360 degrees can be realized by correcting the deviation of the holding angle between the wafer 5 and the wafer 5 in two times, namely, when the wafer 5 is transferred to the temporary placement position and when it is received from the temporary placement position.

Further, according to the multi-joint robot 1, the orientation / holding angle θe of the wafer 5 can be detected by rotating the wafer 5 in the rotation region directly above the multi-joint robot 1. Further, since the temporary placement hand parts 26, 26 are provided on the base 2 of the articulated robot 1, the wafer 5 is placed at the temporary placement position at a predetermined angle, and the hand part 6 is temporarily removed to remove the predetermined angle θe. The orientation work for rotating and re-holding the wafer 5 can be performed without using the multi-joint robot 1 and a dedicated device separately installed.
Therefore, it is possible to reduce the floor area of the clean room in which the work including the orientation of the wafer 5 is performed.
Equipment cost can be reduced.

The rotation of the wafer 5 for detecting the notch 5a is performed while the wafer 5 is held by the hand section 6, and the temporary placement position of the wafer 5 is the temporary placement hand sections 26, 26. Therefore, other members do not come in contact with both surfaces of the wafer 5 during orientation of the wafer 5. Therefore, even if orientation of the wafer 5 whose both surfaces are polished is performed, there is no possibility that the contact portion cannot be commercialized, and the yield can be improved.

Further, in the articulated robot 1 of this embodiment, the first arm is the rotary table 3, and the second arm 4 is composed of an arm mechanism in which two arm bodies 7 and 8 are connected. The second arm 4 is an extendable and retractable arm as a whole, and even when the rotation center of the rotary table 3 and the rotation center of the wafer 5 held by the hand unit 6 are deviated from each other, the second arm 4 is expanded and contracted while the rotary table 3 is extended. By rotating, the wafer 5 can be rotated without being eccentric so that the rotation center of the rotary table 3 and the rotation center of the wafer 5 are coincident with each other. For this reason,
Since the edge of the circular wafer 5 passes through the fixed point, the notch 5a
It means that only one sensor 25 is required to detect
It is possible to prevent an increase in the number of parts.

Further, since the first arm is the rotary table 3 in this embodiment, the stability of rotation of the first arm can be improved. Particularly, it is difficult to prevent vibrations in the first arm because a larger moment acts than in the other arms. However, according to the rotary table 3 of the present embodiment, it is possible to increase the diameter of the support bearings, so that vibrations are effectively prevented. can do. Therefore, the vibration of the arms 3 and 4 as a whole can be prevented, so that the orientation accuracy can be improved.

Further, according to the articulated robot 1 of the present embodiment, the second arm 4 may be expanded and contracted in order to linearly move the hand portion 6, and the rotary table 3 and the second arm 4 have singular points. It never goes into a state. Therefore, the rotary table 3 does not rotate at a particularly high speed, and the vibrations of the arms 3 and 4 can be prevented. Thereby, the stability of the operation of the articulated robot 1 can be improved. In addition, since the position of the center of rotation of the second arm 4 that expands and contracts can be changed by rotating the rotary table 3 when the hand unit 6 is moved linearly, the direction of expansion and contraction of the second arm 4 is limited to a radial direction. Absent. Therefore, the degree of freedom in arranging the articulated robot 1 and the process device 10 can be increased. Thereby, workability can be improved.

Moreover, according to the articulated robot 1 of this embodiment, the pulleys 7a, 7a are used as the extension / contraction mechanism of the second arm 4.
Since a combination of b, 8a, 8b and belts 7c, 8c is used, it can be used in a clean room with less wear. Therefore, it becomes suitable for carrying the semiconductor wafer 5 in the clean room. Further, since the number of arms is substantially three, it is possible to provide the articulated robot 1 that can be housed in a range narrower than the radius of rotation of the hand section 6.

However, the extension / contraction mechanism of the second arm 4 is not limited to the combination of the pulleys 7a, 7b, 8a, 8b and the belts 7c, 8c. For example, the second arm may be composed of two arms that expand and contract in a linear direction by a slider and a ball screw. In this case as well, it is of course possible to improve the degree of freedom of arrangement of the process device 10 and perform linear motion in the vicinity of the base 2.

The above-described embodiment is an example of the preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, the sensor having one detection unit is used as the sensor 25, but the present invention is not limited to this. For example, the sensor 25 may be provided with a plurality of detection units. Specifically, as shown in FIG. 15, the six detection units of the first sensor 25a to the sixth sensor 25f can be installed linearly. In this case, since the edge of the wafer 5 can have a width in the detectable area, the notch 5a can be detected even if the wafer 5 rotates while being eccentric.

Here, as shown by the solid line in FIG.
A sine wave line is drawn by sequentially connecting the rotation angles at which the edges of the wafer 5 are detected by the sensor 25a to the sixth sensor 25f. At the notch 5a portion, the sine wave line is cut out in the shape of the notch 5a. As a result, which sensor 25a
The position of the notch 5a can be detected depending on which rotation angle of 25 f or 25 f the notch 5a is detected.

Further, since the depth of the notch 5a is known, in a region which is inward from the edge of the wafer 5 by the depth of the notch 5a, that is, in a region between the solid line and the broken line in FIG. If only the sensors 25a to 25f detect the notch 5a
Can be detected. Therefore, the hatched area in FIG. 17 is preset as the detectable area. Then, the notch 5a can be detected by any of the sensors 25a to 25f by operating only the sensors 25a to 25f corresponding to the detectable area according to the rotation angle of the wafer 5 to perform detection. Therefore,
Since it is not necessary to detect all the sensors 25a to 25f at the same time, the detection circuit can be simplified.

Further, in the above-mentioned sensor 25, a plurality of sensors are arranged linearly, but the present invention is not limited to this. For example, as shown in FIG. 18, the first sensor 25a to the sixth sensor 25f can be arranged in a 2 × 3 grid pattern. In this case, the sensors 25a to 25f are slightly arranged with respect to the diameter of the wafer 5 so that each sensor 25a
The length of the diameter of the wafer 5 detected by 25 f can be different. As a result, it becomes possible to detect the edge portion at narrow intervals without making the sensors 25a to 25f adjacent to each other. Moreover, in the sensor 25 shown in FIG. 18, since the sensors 25a to 25f are arranged apart from each other, mutual interference between the optical sensors does not occur.

Then, the first sensor 25a to the sixth sensor 2
When 5f is arranged as shown in FIG. 18, each sensor 25
a to 25f are displaced in the circumferential direction of the wafer 5. That is, FIG. 19 shows the relative positions of the sensors 25a to 25f in the circumferential direction. For this reason, when the first sensor 25a to the sixth sensor 25f having such an arrangement are detected based on the time chart as shown in FIG. 17, a shift occurs in the circumferential direction, so that as shown in FIG. The positions of the detectable regions of the 1st sensor 25a to the 6th sensor 25f with respect to the rotation angle of the wafer 5 are set to be shifted based on the relative position in the circumferential direction. By performing the detection by the first sensor 25a to the sixth sensor 25f based on the corrected time chart shown in FIG. 20, the position of the notch 5a can be accurately detected without causing a deviation in the circumferential direction.

According to the articulated robot 1 using the sensor 25 shown in FIGS. 15 to 20, the orientation of the wafer 5 is detected by detecting the position of the notch 5a even if the wafer 5 rotates while being eccentric with respect to the base 2. It can be carried out. Therefore, the arms 3 and 4 of the articulated robot 1 can be rotated with the minimum radius. That is, the rotation diameters of the arms 3 and 4 of the articulated robot 1 shown in FIG. 15 are equal to the total length of the hand portion 6 as indicated by the imaginary line in the figure. On the other hand, when the arms 3 and 4 are rotated while the second arm 4 is expanded and contracted so that the wafer 5 is not eccentric, the rotation diameter of the arms 3 and 4 becomes large. Therefore, according to the articulated robot 1 using the sensor 25 shown in FIGS. 15 to 20, the rotation diameters of the arms 3 and 4 can be reduced, so that the space occupied by the articulated robot 1 can be reduced.

Further, although the wafer 5 is used as the work in the above-mentioned embodiment, the invention is not limited to this, and for example, a liquid crystal glass substrate can be used.

[0050]

As is apparent from the above description, according to the articulated robot of the first aspect, the sensor for detecting the detected portion formed on the work is composed of the first arm and the second arm. In addition to being provided in the rotation range of the workpiece, a temporary placement hand unit for sandwiching and holding the workpiece at the temporary placement position is provided integrally with the base, and the workpiece is rotated by the first arm and the second arm while holding the workpiece in the hand unit. While detecting the detected portion by the sensor, the holding angle of the work is detected, and the first arm and the second arm are arranged so that the detected portion has an angle to be located at the second position based on the holding angle. To rotate and position the work, and hold the work by sandwiching the work with the temporary placement hand part in the positioned state.
Further, since the first arm is a rotary table and the second arm is composed of an arm mechanism in which two arm bodies are connected, it is possible to rotate the work directly above the articulated robot and The holding angle can be detected. Further, since the temporary placement hand unit is provided on the base of the articulated robot, the workpiece is placed at the temporary placement position at a predetermined angle, the hand unit is temporarily removed, and the hand unit is rotated by a predetermined angle to re-hold the workpiece. The work can be performed without using a dedicated device separately installed in addition to the articulated robot. Therefore, it is possible to reduce the floor area of the clean room in which the work including the wafer orientation is performed, and it is possible to reduce the equipment cost.

The rotation of the work for detecting the detected part is performed while the work is held by the hand part, and the temporary placement position of the work is the temporary placement hand part. No other member touches both sides of the workpiece during orientation. Therefore, even if orientation of a work polished on both sides is performed, there is no possibility that the contact portion cannot be commercialized, and the yield can be improved.

Further, the second arm is an extendable and retractable arm as a whole, and even if the rotation center of the first arm and the rotation center of the work held by the hand portion are deviated from each other, the second arm
By rotating the first arm while expanding and contracting the arm, the work can be rotated without eccentricity so that the rotation center of the first arm and the rotation center of the work coincide with each other. For this reason, since the edge of the disk-shaped work passes through the fixed point, only one sensor for detecting the detected portion is required, and an increase in the number of parts can be prevented.

Further, in the articulated robot according to claim 2,
The turntable is rotatably held on the base, and the sensor and the temporary placement hand unit are attached to the base. Therefore, since the base, the rotary table, the sensor, and the temporary placement hand unit can be integrated, the wafer orientation can be performed without disposing a dedicated orientation mechanism.

[Brief description of drawings]

FIG. 1 is a plan view showing the operation of an articulated robot of the present invention, in which (A) is a state in which a wafer is first installed in a rotation range,
(B) is the state where the notch is detected by the sensor, (C)
Is a state in which the wafer is rotated to the temporary placement position, (D) is a state in which the wafer is remounted by the hand portion facing the reference direction, and (E) is a state in which the wafer is placed on the process apparatus.

FIG. 2 is a vertical cross-sectional view showing an operating part such as an arm of an articulated robot.

FIG. 3 is a perspective view showing an operating part such as an arm of an articulated robot.

FIG. 4 is a side view showing a state in which the articulated robot takes out the wafer from the first position.

FIG. 5 is a side view showing a state in which the articulated robot first sets a wafer in a rotation range.

FIG. 6 is a side view showing a state in which a notch is detected by a sensor of the articulated robot.

FIG. 7 is a side view showing a state in which the articulated robot rotates the wafer to a temporary placement position.

FIG. 8 is a side view showing a state in which an articulated robot holds a wafer on a temporary placement hand unit.

FIG. 9 is a side view showing a state in which the articulated robot retakes the wafer by the hand unit facing the reference direction.

FIG. 10 is a side view showing a state in which a multi-joint robot places a wafer on a process apparatus.

FIG. 11 is a side view showing a state where a sensor detects an edge portion of a wafer.

FIG. 12 is a side view showing how a notch of a wafer is detected by a sensor.

FIG. 13 is a plan view showing another operation of the articulated robot, FIG. 13 (A) shows a state in which a wafer is first installed in a rotation range,
(B) is the state where the notch is detected by the sensor, (C)
Is a state in which the wafer is rotated by the remaining angle from the temporary placement position, (D) is a state in which the wafer is remounted by the hand unit rotated by the remaining angle from the reference direction, and (E) is the hand unit is rotated in the reference direction. It is in a state.

FIG. 14 shows a state in which a wafer is placed on a process device by an articulated robot.

FIG. 15 is a plan view of an articulated robot showing another embodiment of a sensor.

FIG. 16 is a graph showing the relationship between the wafer edge detection state by the first to sixth sensors and the wafer rotation angle.

FIG. 17 is a time chart showing the relationship between the detection area of the edge of the wafer by the first to sixth sensors and the rotation angle of the wafer.

FIG. 18 is a plan view showing another embodiment of the sensor.

FIG. 19 is a graph showing the relationship between the relative position at which the edge of the wafer is detected by the first to sixth sensors and the rotation angle of the wafer.

FIG. 20 is a time chart showing the relationship between the detection area at the edge of the wafer by the first to sixth sensors and the rotation angle of the wafer.

FIG. 21 is a plan view showing the arrangement of a conventional articulated robot, an orientator, and the like.

[Explanation of symbols]

1 Articulated robot 2 bases 3 Rotating table (1st arm) 4 second arm 5 wafers (work) 5a Notch (detected part) 6 Hand section 7 Base side arm (arm body) 8 Hand side arm (arm body) 25 sensors 26 Temporary hand unit θe Workpiece holding angle

Continued front page    F term (reference) 3C007 AS24 BS15 BT11 BT14 CT05                       CY12 DS01 ES17 EV02 HS27                       HT02 HT16 HT19 KS04 KV11                       KX02 LT06 LT12 NS13                 5F031 CA02 CA05 DA01 FA01 FA02                       FA07 FA11 FA12 GA36 GA43                       GA47 GA49 JA14 JA17 JA28                       JA35 KA14 LA13 NA02

Claims (2)

[Claims] 1. A first arm rotatably connected to a base has a second arm rotatably connected thereto, and a hand portion capable of holding a work is provided at a tip end of the second arm, and at a first position. In a multi-joint robot in which a certain work is taken out by the hand unit and temporarily placed at a temporary placement position, the work at the temporary placement position is again picked up by the hand unit and set at the second position, the work is formed on the work. A sensor for detecting the detected part is provided in the rotation range of the work by the first arm and the second arm, and a temporary placement hand part for sandwiching and holding the work at the temporary placement position is provided on the base. And integrally detecting the detected part by the sensor while rotating the work by the first arm and the second arm while holding the work in the hand part and detecting the detected part by the sensor. The holding angle of the work is detected, and the work is rotated and positioned by the first arm and the second arm so that the detected portion has an angle that should be located at the second position based on the holding angle. Then, the workpiece is sandwiched and held by the temporary placement hand portion in the positioned state, and the first arm is a rotary table, and the second arm is an arm mechanism in which two arm bodies are connected. An articulated robot characterized by consisting of. 2. The articulated robot according to claim 1, wherein the rotary table is rotatably held on the base, and the sensor and the temporary placement hand unit are attached to the base.