TWI664515B - Processing device - Google Patents

Abstract

The object of the present invention is to create a robot that can recognize a wafer even when the wafer is stored in a cassette in a tilted state, and carry out the wafer without breaking it. The solution is to allow the robot to enter the cassette and release the control of the turning motor from the control unit. The robot is set to be rotatable and moved towards the wafer. When the robot contacts the wafer and makes When the angle recognized by the encoder is changed, it is judged that the wafer already contained in the cassette is tilted. Since the tilt of the wafer can be detected by detecting the rotation of the robot, the situation where the robot collides with the wafer and breaks the wafer can be prevented.

Description

Processing device Field of invention

The present invention relates to a processing apparatus having a robot for carrying wafers out of a cassette.

Background of the invention

To carry wafers out of a cassette that holds various wafers in multiple layers, a robot with a plate-shaped robot and an arm that connects the robot to the front end and can move up and down is used. In the robot, a reducer is connected to a servo motor, and the position of the manipulator is controlled by the rotation angle control of the servo motor. In addition, an encoder is connected to the rotation axis of the servo motor, and the position of the robot can be identified by the encoder identifying the rotation angle of the servo motor. By using an absolute encoder as an encoder, a technique for preventing a positional displacement of a robot has also been disclosed (see, for example, Patent Documents 1 and 2).

A pair of opposing support grooves are formed on both inner side surfaces of the cassette, and each wafer is accommodated by being supported by the support grooves. On the other hand, a space is formed in the central portion where the robot can move in the vertical direction. When carrying wafers out of the cassette, the robot is moved into the cassette, and the robot is moved upward or downward in the center while detecting the presence of wafers in each layer of the cassette. move. Therefore, when the wafer does not exist, the robot moves in the vertical direction.

The methods for detecting the presence of a wafer include a method of detecting whether the wafer has been placed on the robot by a sensor such as a light sensor provided on the robot, and a method of detecting when the wafer is attracted to the robot by the robot. The method of detecting the change of the pressure value of the wafer.

Prior art literature Patent literature

Patent Document 1: Japanese Patent Laid-Open No. 2010-238174

Patent Document 2: Japanese Patent Laid-Open No. 2012-106300

Summary of invention

However, when the wafer is stored in a cassette in a tilted state, the wafer and the robot are tilted differently. Therefore, the recognition by the sensor and the recognition by the pressure value at the time of suction are performed. In either case, there is a case where the robot cannot recognize the wafer even though it exists.

In addition, when the wafer is accommodated in the cassette in a tilted state and it is recognized that there is no wafer on a predetermined layer of the cassette, the robot will be moved to the next layer. Therefore, there is a problem that the robot collides with the tilted wafer and breaks the wafer.

The present invention has been made in view of such problems, and an object thereof is to create a case where a robot moves up and down in a cassette to carry out a wafer, even if the wafer is housed in the cassette in an inclined state. In this case, the wafer can still be identified, and the wafer can be carried out in a manner that does not break it.

The present invention is a processing apparatus including a robot for carrying wafers contained in a cassette out of the cassette and a processing mechanism for processing wafers carried out by the robot. In the processing apparatus, the robot is provided with a holding wafer A robot, a reversing mechanism that reverses the front and back surfaces of the wafer held by the robot, and a moving mechanism that moves the robot to a predetermined position, and the reversing mechanism is provided for reversing the front and back surfaces of the wafer held by the robot A reversing shaft of the rotating shaft, a reversing motor connected to the reversing shaft, a control unit for driving the reversing motor, and an encoder connected to the reversing shaft and detecting the rotation angle of the reversing shaft, further comprising a judging unit, the judging unit By moving the robot into the cassette with the moving mechanism and releasing the control of the turning motor from the control unit, the robot can rotate freely to move it closer to the wafer, and the robot contacts the wafer and When the angle recognized by the encoder is changed, it is judged that the wafer already contained in the cassette is tilted.

In the present invention, since the manipulator that has entered the cassette can release the control of the motor, it can move the reversing axis as a center toward the wafer in a freely rotating state, so the wafer is stored in the wafer in an inclined state When the cassette is being boxed, the robot will also rotate to tilt with the tilt of the wafer. Thereby, the tilt of the wafer can be detected by detecting the rotation of the robot, so that it is possible to prevent the robot from colliding with the wafer and damaging the wafer.

1‧‧‧Grinding device

20‧‧‧ holding table (holding mechanism)

21‧‧‧ handover area

22‧‧‧ Processing Area

30‧‧‧Grinding mechanism

31‧‧‧ Spindle housing

32, 92‧‧‧ Motor

33‧‧‧Mount

34‧‧‧Grinding Wheel

35‧‧‧ ground vermiculite

36‧‧‧ bracket

4a, 4b‧‧‧ cassette

40a, 40b‧‧‧ Cassette Platform

41‧‧‧ opening

42‧‧‧Top plate

43‧‧‧Side

431‧‧‧ inside

432‧‧‧support groove

44‧‧‧ floor

50‧‧‧ Robot

51, 51a‧‧‧ manipulator

511‧‧‧base

512‧‧‧Division

513‧‧‧attraction

514‧‧‧wafer detection sensor

515‧‧‧rotation axis

52‧‧‧ Overturn mechanism

521‧‧‧ Flip axis

522‧‧‧turn motor

523‧‧‧Control Department

524‧‧‧Encoder

525‧‧‧Judgment Department

53‧‧‧mobile agency

531‧‧‧Shaft

532‧‧‧arm

533‧‧‧Driver

6‧‧‧Temporary workbench

61‧‧‧mounting table

62‧‧‧pin

7‧‧‧cleaning agency

71‧‧‧washing table

81‧‧‧The first transfer agency

82‧‧‧ The second transfer agency

90‧‧‧Grinding feed mechanism

91‧‧‧ball screw

93‧‧‧rail

94‧‧‧ Lifting plate

W, W1, W2, W3, W4, W5, W6, W7, W8, W9, W10

W1a, W4a‧‧‧ lower surface

X, Y, Z‧‧‧ directions

θ, θ1, θ2‧‧‧ angle

FIG. 1 is a perspective view showing a grinding apparatus.

FIG. 2 is a perspective view showing a manipulator and a cassette.

FIG. 3 is a front view showing a state where the robot has entered the cassette.

FIG. 4 is a front view showing a state in which a robot holds a wafer.

FIG. 5 is a front view showing a state in which the robot is rotated while contacting the inclined wafer.

FIG. 6 is a front view showing a state where the robot arm has been removed from the tilted wafer.

FIG. 7 is a front view showing a state in which the wafer tilt is corrected and accommodated.

FIG. 8 is a front view showing a state where the robot enters the cassette after the tilt of the wafer is corrected.

FIG. 9 is a front view showing a state where another robot hand contacts the inclined wafer.

FIG. 10 is a front view showing a state where the robot hand has been rotated.

Forms used to implement the invention

The grinding device 1 shown in FIG. 1 is a type of processing device to which the present invention is applied, and is a device for grinding a wafer held on a holding table 20 by a grinding mechanism 30.

A cassette stage 40a, 40b is provided at the front of the grinding apparatus 1, and the cassette stages 40a, 40b can mount cassettes 4a, 4b that accommodate wafers. The cassette stages 40a and 40b are arranged in the X-axis direction. The wafer cassette 4a contains wafers before grinding, and the wafer cassette 4b contains wafers after grinding.

A robot 50 is disposed behind the cassette platforms 40a and 40b, and the robot 50 is used to carry out wafer wafers before grinding from wafer cassette 4a and wafer wafers after grinding to wafer cassette 4b. As shown in FIG. 2, this robot 50 includes a robot arm 51 that holds a wafer, a turning mechanism 52 that reverses the front and back surfaces of the wafer held by the robot arm 51, and a moving mechanism 53 that moves the robot arm 51 to a predetermined position. , And the robot arm 51 can enter the inside of the cassettes 4a, 4b.

The robot arm 51 is formed into a flat plate as a whole, and includes a base portion 511 and two branch portions 512 branched from the base portion 511. Each branch portion 512 is provided with a suction port 513. The base 511 is provided with a wafer detection sensor 514 that detects the presence of a wafer. The wafer detection sensor 514 is located at the center of the width direction of the robot arm 51 (that is, a direction orthogonal to the horizontal direction with respect to the entry directions to the cassettes 4 a and 4 b). The wafer detection sensor 514 may be a light sensor or a sensor of a type that detects a wafer by a change in pressure value when it is attracted to the wafer.

The turning mechanism 52 includes a turning shaft 521 connected to the base 511, a turning motor 522 connected to the turning shaft 521, a control unit 523 that controls the turning motor 522, and an encoder connected to the turning shaft 521 and detects a rotation angle of the turning shaft 521. 524, and a judging unit 525 that judges whether the flip shaft 521 has been rotated based on the information about the rotation accuracy from the encoder 524. The axis of the turning axis 521 will become the rotation axis 515 of the robot arm 51. The encoder 524 is an absolute type in which the rotation angle from the origin is memorized even when the power is turned off.

The moving mechanism 53 includes a shaft portion 531 connected to the reversing motor 522 and the encoder 524, a flexible arm portion 532 having a shaft portion 531 at a tip end, and a driving portion 533 for rotating and lifting the arm portion 532.

As shown in FIG. 1, a temporary table 6 and a cleaning mechanism 7 are arranged in a movable area of the robot hand 51 of the robot 50. The temporary table 6 is composed of a mounting table 61 on which wafers before grinding are mounted, and a plurality of supporting pins 62 protruding from the mounting table 61 and arranged to move radially. On the other hand, the cleaning mechanism 7 is provided with a cleaning table 71 that is capable of holding the wafer after grinding and is rotatable, and sprays cleaning water or high-pressure gas on the wafer held on the cleaning table 71. Shown nozzle.

The holding table 20 is formed so as to be rotatable and movable in the Y-axis direction between a handover region 21 where wafer transfer is performed and a processing region 22 where wafer grinding is performed.

A first transfer mechanism 81 for transferring wafers before grinding from the temporary table 6 to the holding table 20 located in the transfer area 21 is disposed near the temporary table 6. On the other hand, a second transfer mechanism 82 for transferring the ground wafer from the holding table 20 located in the transfer area 21 to the cleaning table 71 of the cleaning mechanism 7 is arranged near the cleaning mechanism 7.

The grinding mechanism 30 includes a spindle having a vertical axis, a spindle housing 31 that supports the spindle in a rotatable manner, a motor 32 connected to one end of the spindle, and a spindle detachably mounted on the spindle through a mount 33. Lower grinding wheel 34. A grinding vermiculite 35 fixed in a ring shape is provided at a lower portion of the grinding wheel 34.

The grinding mechanism 30 is driven by the grinding feed mechanism 90 to perform grinding feed in the Z-axis direction. The grinding feed mechanism 90 includes a ball screw 91 having an axial center in the Z-axis direction, a motor 92 connected to one end of the ball screw 91, a guide rail 93 extending in parallel with the ball screw 91, and one of them. One side is connected to the bracket 36 holding the grinding mechanism 30, and the other side is slidably connected to the pair of guide rails 93, and a nut provided inside is screwed to the lifting plate 94 of the ball screw 91. The grinding feed mechanism 90 can raise and lower the elevation plate 94 along the pair of guide rails 93 in the Z-axis direction by rotating the ball screw 91 with the motor 92, and raise and lower the grinding mechanism 30 in the Z-axis direction.

In the grinding device 1 configured as described above, the wafer is taken out one by one from the cassette 4a by the robot 50. And it is mounted on the mounting table 61 of the temporary table 6. Then, the pins 62 are moved toward each other so as to align the wafer to a predetermined position.

After that, the first transfer mechanism 81 transfers the wafer to the holding table 20 located in the transfer area 21 and holds the wafer on the holding table 20. Then, the wafer is moved below the grinding mechanism 30 by moving the holding table 20 to the processing area 22.

Next, the motor 32 of the grinding mechanism 30 rotates the grinding wheel 34, and the grinding feed mechanism 90 lowers the grinding mechanism 30, and the rotating grinding vermiculite 35 contacts the upper surface of the wafer to perform the wafer Grinding. Then, when the wafer is formed to a desired thickness, the grinding feed mechanism 90 raises the grinding mechanism 30 to finish grinding.

After the grinding is completed, the holding table 20 is moved to the transfer area 21. Then, the second conveyance mechanism 82 holds the ground wafer and moves it to the cleaning table 71 of the cleaning mechanism 7, and cleans the ground wafer in the cleaning mechanism 7. After cleaning, the robot 50 holds and stores the cleaned wafers in the cassette 4b.

As shown in FIG. 3, the cassette 4 a is a box formed with an opening portion 41. It has a top plate 42, two side plates 43 suspended from both ends of the top plate 42, and a bottom plate 44 connected to the lower ends of the two side plates 43. A plurality of support grooves 432 are formed on the inner surface 431 of the two side plates 43 at equal intervals in the vertical direction. Wafers W1 to W10 are housed in each support groove 432 of the cassette 4a. In addition, the cassette 4b shown in FIG. 1 is also formed in the same structure, but the wafer is not accommodated before the grinding is started.

The following is a description of a case where wafers are carried out one by one starting from the wafer W1 accommodated in the lowermost support groove 432. As shown in FIG. 3, the wafer cassette 4 a includes a wafer W4 housed in a state of being inclined while being stretched on left and right support grooves 432 having different heights. On the other hand, the wafers W1 to W3 and the wafers W5 to W10 are housed in a state where they are mounted on the left and right support grooves 432 of the same height without being inclined.

The robot 50 shown in FIG. 2 turns off the power of the turning motor 522 to form the robot arm 51 in a rotatable state, and enters the lowermost stage accommodated in the opening 41 as shown in FIG. 3 in this state. Below the wafer W1 on the support groove 432. In addition, the power of the turning motor 522 may be turned off after the robot 51 enters through the opening 41.

Next, as shown in FIG. 4, the robot arm 51 is raised. In this way, the wafer detection sensor 514 provided in the robot arm 51 detects the wafer W1. At this stage, the power of the turning motor 522 is turned on to release the rotatable state of the robot. Since the wafer W1 in the lowermost layer is not tilted, the robot arm 51 does not rotate until the wafer W1 is detected by the wafer detection sensor 514. Thereby, the lower surface W1a of the wafer W1 can be attracted by making the attraction force act on the suction port 513 of the robot hand 51, and In the state, the robot 51 is retracted and the wafer W1 is carried out from the cassette 4a. Then, the turning motor 522 turns the manipulator 51 to turn the front and back surfaces of the wafer W1, and the lower surface W1a of the surface to be ground faces upward, and is transferred to the temporary worktable 6 shown in FIG. 1.

Next, the power of the turning motor 522 is turned off, the robot arm 51 enters the cassette 4 a again, and the robot arm 51 is raised, and similarly, the wafer W2 is sucked out of the cassette 4 a to be transferred to the temporary table 6. . In addition, at this time, the wafer W1 that has been previously transferred is transferred to the holding mechanism 20 by the first transfer mechanism 81. Similarly, the wafer W3 is also carried out from the cassette 4 a and transferred to the temporary table 6. When the wafers W2 and W3 are carried out, the power of the turning motor 522 is turned off at the stage when the wafers W2 and W3 are detected by the wafer detection sensor 514.

Next, when the robot arm 51 is rotatable while the power of the turning motor 522 is turned off, the robot arm 51 is moved into the cassette 4a and raised as shown in FIG. The side (left side) is tilted downward, so before the wafer detection sensor 514 detects the wafer W4, the branching portion 512 (see FIG. 2) on the left side of the robot 51 contacts the lower surface W4a of the wafer W. In this way, since the robot arm 51 is rotatable, the robot arm 51 is rotated by θ degrees in the same direction (clockwise) as the wafer W4 is formed.

The encoder 524 detects this rotation of the robot arm 51. The judging unit 525 judges that the wafer W4 is tilted based on the rotation, and notifies the control unit 523 of the information of the content. In this way, the control unit 523 stops the rising of the robot 51, and as shown in FIG. 6, after lowering the robot 51, Retreat from the cassette 4a. When the robot 51 is retracted from the cassette 4a in this way, the operator corrects the wafer W4 to an appropriate state without tilting as shown in FIG. 7.

When the wafer W4 is accommodated in this manner without being tilted, as shown in FIG. 8, the robot arm 51 is brought into the lower portion of the wafer W4 and then raised to attract the lower surface W4 a of the wafer W4. The wafer W4 is carried out. Thereafter, as with the wafers W2 and W3, the wafers W5 to W10 are sequentially sucked out and carried out.

In the case where the robot arm 51a shown in FIG. 9 is generally narrower in width than the robot arm 51 type, the robot arm 51a can be turned freely even when the power of the turning motor 522 is turned off, and the wafer 51a is in contact with the wafer. W4, before the robot 51a is rotated, it needs more ascending amount than a robot with a wide width like the robot 51. In addition, in a case where the wafer W4 is detected by the wafer detection sensor 514, a larger amount of ascent is required than that of the robot 51. As a result, while the power of the turning motor 522 is kept off as it is, the height of the manipulator 51 is further increased by an amount equivalent to, for example, the height of the support groove 432 on the next level, as shown in FIG. 10, During this ascent process, the determination unit 525 is caused to detect the tilt of the robot arm 51 and notified to the control unit 424.

In this way, the amount of lift of the robot for detecting the tilt of the wafer is adjusted in accordance with the width of the robot (relative to the length in the direction orthogonal to the horizontal direction of the cassette 4a), The inclination of the wafer can be reliably detected, so that the situation of wafer damage can be prevented beforehand.

In addition, in the above-mentioned embodiment, although the wafer which is stored in the lowermost layer of the cassette 4a is first carried out, and when the robot is raised, the The case of sequentially carrying out wafers has been described, but a method may also be adopted in which the wafers stored in the uppermost layer of the cassette 4a are carried out first, and when the robot is lowered, the wafers are sequentially carried out from the upper wafer.

Claims (1)

A processing apparatus includes a robot for carrying wafers contained in a cassette from the cassette, and a processing mechanism for processing a wafer carried out by the robot. In the processing apparatus, the robot is provided with a mechanism for holding a wafer. A robot arm, a turning mechanism for inverting the front and back surfaces of the wafer held by the robot arm, and a moving mechanism for moving the robot arm to a predetermined position, the turning mechanism is provided with a table for making the wafer held by the robot arm The turning axis of the rotation axis when the back is reversed, the turning motor connected to the turning axis, the control unit driving the turning motor, and an encoder connected to the turning axis and detecting the rotation angle of the turning axis, and the processing The device further includes a judging unit that causes the robot to enter the cassette by the moving mechanism and releases the control of the turning motor from the control unit so that the robot can rotate freely to approach it. When the direction of the wafer is moved and the robot is in contact with the wafer and the angle recognized by the encoder is changed, it is determined that the wafer that has been accommodated in the cassette is inclined.