JP2007129063A - Teaching device for wafer transfer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a teaching device capable of achieving high teaching precision without depending on an operator while reducing burdens on the operator and a time required for teaching-work in the teaching work of, especially, the height direction for a wafer transfer device. <P>SOLUTION: The teaching device is provided with an inner plate 1 placeable on a placing pin in a module, an outer plate 2 vertically freely ascendably/descendably supporting the inner plate 1, a light-shielding plate 6 mounted to the inner plate 1, and a transmission sensor 3 mounted to the outer plate 2 so as to allow the light-shielding plate 6 to block a light path. The device is arranged so that a state of the transmission sensor 3 is changed, when the outer plate 2 is vertically moved relative to the inner plate 1 after placing the inner plate 1 on the placing pin in the module. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus used in teaching a robot in a wafer transfer apparatus, and more particularly to a teaching apparatus that teaches a position in a height direction.

  In a wafer transfer apparatus using a robot, it is necessary for the robot to accurately transfer the wafer to a predetermined position in the module in order to prevent problems such as a wafer falling or being unable to perform processing correctly. However, in actuality, the wafer can be accurately transferred to the specified position even if the robot is moved to the designed position due to various causes such as dimensional errors of the parts constituting the wafer transfer device and assembly errors of the device. I can't. Therefore, prior to the operation of the wafer transfer apparatus, a robot teaching operation is required.

  Conventional robot teaching work is finally performed visually by an operator while finely moving the robot near the target position. Regarding the height direction, for example, when positioning with the tip of the mounting pin in the module as a reference, the teaching position is confirmed by measuring the gap between the mounting pin and the wafer transfer unit of the robot with a gauge or the like. . However, the number of robots and modules in the apparatus has increased as the density and height of semiconductor manufacturing apparatuses have increased, and the teaching work has become complicated and requires a lot of time. Furthermore, it is difficult to confirm the teaching position by visual inspection, and the teaching work for the module installed at a high position requires work in an unstable posture, which increases the burden on the operator, and also varies the teaching accuracy by the operator. There was also a problem that occurred.

  In order to solve such a problem, for example, Patent Document 1 describes an automatic teaching jig for a substrate transport apparatus as shown in FIG. The jig 200 has a main body 210 that can be held by the arm 31b of the wafer transfer apparatus, and the detected portion 122 provided at a transfer position of an arbitrary wafer processing unit is loosely inserted into the main body 210. For this purpose, a hole 270 is formed, and optical sensor heads 231, 232, 241, 242 for detecting the edge portion of the detected part 122 are provided around the hole 270. The optical sensor heads 231 and 232 are a pair of optical sensor heads composed of a light projecting part and a light receiving part for detecting the detected part 122 in the Y-axis direction, and the optical sensor heads 241 and 242 are covered in the X-axis direction. It is a set of optical sensor heads composed of a light projecting unit and a light receiving unit for detecting the detection unit 122. From these optical sensor heads, an optical fiber F1 for transmitting and receiving an optical signal is connected to the optical connectors 251 to 254. The teaching jig 200 is set on the arm 31b, the arm 31b is moved so that the detected part 122 provided at a predetermined transport position enters the hole 270 of the main body 210, and the arm 31b is moved in the X-axis direction, Y By moving in the axial direction and the Z-axis direction to obtain the center position of each axis, the reference position of each axis is obtained, and the positional deviation of the substrate transport position is eliminated. In FIG. 9, 35 is an arm support for supporting the arms 31a and 31b, 38 is a holding member, and 39 is a holding table for holding the optical connectors 256 to 263.

Patent Document 2 describes a teaching apparatus for a wafer transfer apparatus as shown in FIG. The teaching apparatus 320 includes an inner plate 301 simulating the shape of a wafer and an outer plate 302 that supports the inner plate 301 so as to be movable up and down. The outer plate 302 includes a projector 303, a light receiver 304, and a mirror 305-1. , 305-2. The inner plate 301 blocks the light path 306 from the light projector 303 to the light receiver 304 by moving the outer plate 302 relatively up and down with the inner plate 301 placed on the placement pin in the processing unit. The position of the inner plate 301 in the height direction is measured and the position is taught.
Japanese Patent Laid-Open No. 2001-156153 (page 12, FIG. 7) Japanese Unexamined Patent Publication No. 2004-146686 (page 9, FIG. 1)

  When the teaching jig described in Patent Document 1 is used, a cylindrical detection target serving as a reference is required in advance. Usually, when placing a wafer in a module, it is often placed on three placement pins in order to reduce the ground contact area with the wafer. The height information of the mounting pins for mounting the wafer on the surface cannot be obtained, and cannot be applied to teaching. In addition, in the method of installing the detected part, the inside of the module is narrow due to the high density of the semiconductor device, it is difficult to install the detected part, and there is also a risk of interference with the mounting pin during the teaching operation.

  Moreover, since the teaching apparatus described in Patent Document 2 reflects the optical path from the projector 303 to the light receiver 304 with the mirrors 305-1 and 305-2, the optical path becomes very long, thereby spreading the light. The influence of the angle on the measurement accuracy in the height direction cannot be ignored, and as a result, there is a problem that the position cannot be taught with high accuracy. Further, there has been a problem that it is difficult to adjust the optical axis of the apparatus itself due to the complicated reflection of the optical path.

  The present invention has been made in view of such problems, and improves teaching accuracy in the height direction, reduces the burden on the operator in teaching work, shortens the time required for teaching work, and variation in teaching accuracy by the operator. The purpose is to eliminate.

  In order to solve the above problem, the present invention is configured as follows.

According to the first aspect of the present invention, there is provided a wafer transfer apparatus including a robot for transferring a wafer placed on a wafer mounting unit to a taught transfer position and a controller for controlling the robot. A teaching device for teaching a position in the height direction, and a thin plate-like outer plate placed on the wafer mounting portion and supported on the outer plate so as to be detachable in the upward direction, and can be mounted at the transfer position A thin plate-shaped inner plate, a transmission sensor that is mounted on either the outer plate or the inner plate, and includes a light emitting unit and a light receiving unit, and the outer plate or the inner plate on which the transmission sensor is not mounted. The teaching device of the transport device includes a light shielding plate that is mounted and shields the light emitting portion and the light receiving portion of the transmission sensor.

According to a second aspect of the present invention, there is provided a wafer transfer apparatus comprising a robot for transferring a wafer placed on a wafer mounting unit to a taught transfer position and a controller for controlling the robot. A teaching device for teaching a position in the height direction, and a thin plate-like outer plate placed on the wafer mounting portion and supported on the outer plate so as to be detachable in the upward direction, and can be mounted at the transfer position A thin plate-like inner plate, mounted on either the outer plate or the inner plate, and comprising at least three transmission sensors each including a light emitting portion and a light receiving portion, and the outer plate or the Each of the transmission sensors when mounted on the inner plate and blocks the light emitting unit and the light receiving unit of the transmission sensor, and the same number of light shielding plates as the transmission sensor, and when the inner plate is mounted at the transport position. Transfer from output A mounting surface equation calculating unit that calculates a surface equation of the mounting transport surface; a mounting angle that calculates a relative angle between the mounting surface described by the transport surface equation and the wafer mounting surface of the wafer mounting unit; And a teaching device for a conveying device including a placement surface angle detection unit.

The invention described in claim 3 is characterized in that the outer plate is an annular disk having a hollow portion, and the inner plate is a disk substantially matching the hollow portion of the outer plate. The teaching device of the conveying device according to 1 or 2 is used.

As described above, according to the first aspect, after being attached to the wafer mounting portion of the robot for the wafer transfer apparatus, if the robot is moved up and down at the target transfer position, the signal of the transmission sensor is detected and the placement surface at the transfer position is detected. Can be measured with high accuracy, so the teaching accuracy in the height direction is improved.
In addition, when the mounting position is within the module, teaching in the height direction in the wafer mounting operation can be performed from outside the module, so that the load on the operator can be reduced and the time required for the teaching operation can also be shortened. . Furthermore, since the measurement in the height direction is not relied on visually, there is an effect that variation in teaching accuracy by the operator does not occur.

  According to the second aspect, the height of the mounting surface in the module can be measured, and the relative inclination between the wafer mounting portion of the wafer transfer device robot and the mounting surface of the transfer position can be measured. Therefore, it is possible to determine the mounting failure of the mounting pin, and to further improve the reliability of the teaching work.

  According to the third aspect of the present invention, the present invention can be applied to various robots and mounting positions by making the inner plate and the outer plate resemble a wafer, thereby providing a versatile teaching device. it can.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an example of a teaching apparatus of a wafer transfer apparatus in the first embodiment of the present invention. As shown in FIG. 1, the teaching apparatus of the wafer transfer apparatus of the present embodiment includes an inner plate 1 having a size that can be placed on a placement pin in a module, and an outer plate that can be placed on a wafer mounting portion of a robot. In general, the inner plate 1 is supported by the outer plate 2. A light-shielding plate 6 is attached to the inner plate 1, and a transmission sensor 3 to which a light emitting unit 4 and a light receiving unit 5 are attached facing each other is mounted on the outer plate 2. Normally, in a state where the inner plate 1 is supported by the outer plate 2, the optical path of the transmission sensor 3 is blocked by the light shielding plate 6.
FIG. 2 shows a block diagram of a control mechanism using the teaching apparatus 10. The output state of the transmission sensor 3 mounted on the teaching apparatus 10 is captured by the CPU 16 via the I / F unit 11, and at the same time, the position information in the height direction of the wafer mounting unit of the robot 12 is connected to the motor of the robot 12. It can be acquired by the encoder 13 and can be taken into the CPU 16 via the servo amplifier 14 and the I / F unit 15. The state of the transmission sensor 3 and the position information in the height direction of the wafer mounting surface are sent to the mounting surface height detector 17 in the CPU 16 to detect the height of the mounting surface, and the teaching position is determined from the height information of the mounting surface. The generation position 18 calculates the teaching position 20 of the robot. The calculated teaching position 20 is stored, and based on the stored teaching position 20, an operation of placing a wafer in the module by the command unit 19 is executed.

  A procedure of teaching work using the teaching apparatus of the wafer transfer apparatus according to the present embodiment will be described. FIG. 3 is a side view of the vicinity of the transmission sensor with the teaching device mounted on the wafer mounting portion of the robot and inserted into the module. In the state of FIG. 3, the inner plate 1 is supported by the outer plate 2, and the optical path 8 of the transmission sensor 3 is blocked by the light blocking plate 6. When the wafer mounting portion of the robot is moved downward from the state of FIG. 3, the inner plate 1 of the teaching apparatus contacts the mounting pins 7 for mounting the wafer in the module as shown in FIG. In the state of FIG. 4, the optical path 8 of the transmission sensor 3 is still blocked by the light shielding plate 6. When the wafer mounting portion of the robot is further moved downward from the state of FIG. 4, the inner plate 1 is placed on the placing pins 7 in the module, and the inner plate 1 is lifted relative to the outer plate 2. Become. When the wafer mounting portion of the robot is further moved downward, the light path 8 of the transmission sensor 3 is detached from the light shielding plate 6 and the light from the light emitting portion 4 reaches the light receiving portion 5 as shown in FIG. A change occurs in the output. The position in the height direction of the robot wafer mounting part in this state is acquired and recorded. Even if the wafer mounting portion of the robot is further moved downward, the transmission sensor 3 remains in the light receiving state as shown in FIG.

  When taking out the wafer mounting portion of the robot equipped with the teaching apparatus from the module, the wafer mounting portion is moved upward from the state of FIG. 6 and returned to the state of FIG. 3 in the reverse procedure to the above. Removal is possible.

  With the above operation, the position in the height direction of the robot wafer mounting portion when the transmission sensor 3 is changed can be obtained. Here, the distance from the end of the light shielding plate 6 to the optical path 8 in the state where the inner plate 1 of FIG. 3 is supported by the outer plate 2 is a, and the distance from the bottom surface of the outer plate 2 to the bottom surface of the inner plate 1 is b. And At this time, when the robot actually mounts the wafer on the wafer mounting portion and places the wafer on the mounting pin, the position where the bottom surface of the wafer contacts the mounting pin 7 is the robot wafer recorded when the transmission sensor 3 changes. It is located upward (a + b) from the height direction position of the mounting portion. The values of a and b can be calculated from the design values of the teaching apparatus, and the position (a + b) above the position in the height direction of the robot wafer mounting portion recorded when the transmission sensor 3 is changed is mounted on the wafer. The teaching operation is completed by teaching the control device as the set position.

  Note that the position in the height direction of the robot wafer mounting portion when the transmission sensor 3 changes in the teaching procedure by the downward movement from FIG. 3 to FIG. 6 was recorded, but the upward direction from FIG. 6 to FIG. The same effect can be obtained by recording the position in the height direction of the robot wafer mounting portion when the transmission sensor 3 changes in the teaching procedure by the movement to. Moreover, the position when the transmission sensor 3 changes in both the downward direction and the upward direction is recorded, and by taking the average value, the influence of hysteresis can be reduced, and a more accurate value can be obtained.

  The direction of the transmissive sensor 3 and the shape of the light shielding plate 6 may be the same as those shown in FIG.

  FIG. 8 is a block diagram of a control mechanism according to the second embodiment of the present invention. In the teaching apparatus according to the second embodiment, three or more transmission sensors 3 each having a light emitting unit 4 and a light receiving unit 5 are installed on the outer plate 2, and the inner plate 1 is positioned to block the optical path 8 of each transmission sensor. Further, the same number of light shielding plates 6 as the transmission sensors 3 are provided. The output state of each transmission sensor 3 is taken into the CPU 16 via the I / F unit 11 in the same procedure as in the first embodiment. Further, the position information in the height direction of the wafer mounting portion of the robot when the output state of each transmission sensor 3 changes can be acquired by the encoder 13 connected to the motor of the robot 12, and the servo amplifier 14, I / O The data can be taken into the CPU 16 via the F unit 15. As a result, three or more positions of the wafer mounting portion where the output state of the transmission sensor 3 changes can be measured, so that the surface of the mounting surface formed by the mounting surface equation calculation unit 21 by the three mounting pins. An equation can be calculated. From the surface equation of the mounting surface, the mounting surface height detector 17 calculates the height of the mounting surface by the mounting pins, and enables teaching in the height direction for the wafer mounting operation. Further, from the surface equation of the mounting surface, the mounting surface angle detector 22 calculates the inclination of the mounting surface, and determines whether there is a mounting surface tilt caused by a mounting pin inclination or a mounting pin installation error. This can improve the reliability of teaching work.

The perspective view of the teaching apparatus which shows 1st Example of this invention The block diagram of the control mechanism for performing the teaching work of 1st Example of this invention The side view which shows a state when the teaching apparatus is inserted in the module of 1st Example of this invention. The side view which shows a state when the inner board of the teaching apparatus of 1st Example of this invention contacts the mounting pin. The side view which shows the state which the inner board of the teaching apparatus of 1st Example of this invention was mounted in the mounting pin, and the change produced the output of the permeation | transmission sensor. The side view which shows the state which the inner board of the teaching apparatus of 1st Example of this invention was mounted in the mounting pin, and the permeation | transmission sensor received light completely. The perspective view of the teaching apparatus which shows another example of the permeation | transmission sensor and light-shielding plate of 1st Example of this invention. The block diagram of the control mechanism for performing the teaching work of 2nd Example of this invention A perspective view showing an example of a conventional teaching apparatus A perspective view showing an example of a conventional teaching apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner plate 2 Outer plate 3 Transmission sensor 4 Light-emitting part 5 Light-receiving part 6 Light-shielding plate 7 Mounting pin 8 Optical path 10 Teaching apparatus 11 I / F part 12 Robot 13a-b Motor encoder 14 Control part 15 I / F part 16 CPU
17 Mounting surface height detection unit 18 Teaching position generation unit 19 Command unit 20 Teaching position 21 Mounting surface equation calculation unit 22 Mounting surface angle detection unit

Claims (3)

A teaching for teaching a position in the height direction at the transfer position to a wafer transfer apparatus comprising a robot for transferring a wafer placed on the wafer mounting unit to a taught transfer position and a control device for controlling the robot. A device,
A thin plate-shaped outer plate placed on the wafer mounting portion;
A thin plate-shaped inner plate that is supported by the outer plate so as to be detachable in the upward direction and can be mounted at the transport position;
Mounted on either the outer plate or the inner plate, a transmission sensor comprising a light emitting part and a light receiving part,
A teaching device for a conveying apparatus, comprising: a light shielding plate which is mounted on the outer plate or the inner plate on which the transmission sensor is not mounted and which blocks a light emitting unit and a light receiving unit of the transmission sensor. A teaching device for teaching a position in the height direction at the transfer position to a wafer transfer device comprising a robot for transferring a wafer placed on the wafer mounting unit to a taught transfer position and a controller for controlling the robot. There,
A thin plate-shaped outer plate placed on the wafer mounting portion;
A thin plate-shaped inner plate that is supported by the outer plate so as to be detachable in the upward direction and can be mounted at the transport position;
Mounted on either the outer plate or the inner plate, at least three transmission sensors comprising a light emitting portion and a light receiving portion;
The same number of light-shielding plates as the transmissive sensor, which is mounted on the outer plate or the inner plate on which the transmissive sensor is not mounted and blocks the light-emitting portion and the light-receiving portion of the transmissive sensor,
A placement surface equation calculation unit that calculates a surface equation of the transport surface at the transport position from the output of each of the transmission sensors when the inner plate is mounted at the transport position;
A teaching apparatus for a transfer apparatus, comprising: a mounting surface angle detection unit that calculates a relative angle between the transfer surface represented by the transfer surface equation and a wafer mounting surface of the wafer mounting unit.   The conveying apparatus teaching apparatus according to claim 1 or 2, wherein the outer plate is an annular disk having a hollow portion, and the inner plate is a disk that substantially matches the hollow portion of the outer plate.

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