JP7303709B2 - processing equipment - Google Patents

Description

The present invention relates to a processing apparatus for processing workpieces such as semiconductor wafers.

A processing apparatus for processing a workpiece such as a semiconductor wafer, and a grinding apparatus for grinding a wafer (see, for example, Patent Document 1) holds a wafer on a chuck table and grinds the wafer with a grinding wheel to a predetermined thickness. there is Further, the fully automatic grinding apparatus is equipped with transport means for loading and unloading wafers onto and from the chuck table.

That is, in a fully automatic grinding apparatus, a robot unloads a plurality of wafers from a cassette storing a plurality of wafers in a shelf shape, places the wafers on a temporary placement table by the robot, and loads the wafers from the temporary placement table to a chuck table by means of loading means. Wafers are being transported. Furthermore, a series of processing operations is performed by transferring the ground wafer from the chuck table to the spinner cleaning table by the carrying-out means, and storing the wafer after the spinner cleaning in the cassette by the robot.

JP 2017-013144 A

A cassette may contain wafers having different thicknesses. If a wafer that is too thick or too thin is transported to the chuck table, the processing means may not be able to grind the wafer appropriately. In order to prevent this, when the thickness of the wafer held on the chuck table before grinding is measured by a thickness measuring instrument equipped with, for example, a contact gauge, if there is a problem with the thickness of the wafer, the grinding device The operator is notified by recognizing an abnormality in the thickness of the steel sheet and issuing an alarm.

However, after the alarm is issued, it takes time to recover the wafer from the chuck table, such as drying the wafer.
Therefore, in the processing apparatus, there is a problem of improving work efficiency by making it possible to recognize whether or not there is a problem with the thickness of the wafer at an earlier stage than holding the wafer on the chuck table.

To solve the above problems, the present invention provides a cassette having a shelf capable of storing a plurality of wafers, a cassette stage on which the cassette is placed, and a wafer stored in the cassette placed on the cassette stage. and a processing means for processing the wafer carried out by the robot and held on the chuck table, wherein the robot comprises a robot hand holding the wafer; a moving means for moving the robot hand; and a determining means for determining whether the thickness of the wafer held by the robot hand is a predetermined normal thickness, wherein the moving means moves the robot hand. and a current control unit for controlling the current flowing through the motor. If the value of the current flowing through the motor is within a predetermined range, it is determined that the held wafer has a normal thickness, and the wafer is conveyed to the chuck table and processed, and the value of the current is increased. However, if it is out of the preset range, it is determined that the held wafer has an abnormal thickness.

The moving means is, for example, reversing moving means for reversing one surface and the other surface of the robot hand.

The moving means is, for example, vertical moving means for vertically moving the robot hand.

The moving means is, for example, horizontal moving means for horizontally moving the robot hand.

In the processing apparatus according to the present invention, the robot comprises a robot hand holding a wafer, a moving means for moving the robot hand, and a judgment as to whether or not the thickness of the wafer held by the robot hand is a predetermined normal thickness. the moving means includes a motor that generates driving force for moving the robot hand; and a current control section that controls current flowing through the motor. The determining means holds a wafer of a predetermined thickness. When the robot hand is operated at a preset speed, that is, when the motor is driven, if the value of the current flowing through the motor is within a preset range, it is determined that the held wafer has a normal thickness. If the wafer is transported to the chuck table and processed, and if the current value is out of a predetermined range, it is determined that the held wafer has an abnormal thickness. When the wafer is held and taken out from the chuck table, the abnormal thickness of the wafer can be detected. can.

Since the moving means is a reversing movement means for reversing one surface and the other surface of the robot hand, after the robot holds and takes out the wafer from the cassette, the robot hand is reversely moved, and the thickness of the wafer is changed. Even if is an abnormal thickness that differs from the normal thickness of the wafer, the abnormality in the thickness can be detected. Efficiency can be improved.

Since the moving means is a vertical moving means for moving the robot hand in the vertical direction, it is possible to notice an abnormality in the thickness of the wafer at the stage when the robot holds and raises the wafer in the cassette and is in the cassette. Therefore, it is possible to eliminate the wasteful operation of transferring a wafer with an abnormal thickness to the chuck table, thereby improving work efficiency.

Since the moving means is a horizontal moving means for moving the robot hand in the horizontal direction, when the robot holds and takes out the wafers from the cassette, or when the robot moves the wafers in the horizontal direction after taking out, the thickness of the wafers does not change. Even if the wafer has an abnormal thickness that is different from the normal thickness, the abnormality in the thickness can be noticed, so that the wasteful operation of transferring the wafer with the abnormal thickness to the chuck table can be eliminated, resulting in work efficiency. can be improved.

It is a perspective view which shows an example of a processing apparatus. It is a perspective view showing an example of a cassette and a robot. FIG. 3 is a perspective view illustrating various pulleys, turning movement means, and X-axis movement means arranged inside each arm of the robot; FIG. 10 is an explanatory view for explaining the operation of judging whether the thickness of the wafer is normal or not, which is performed by the judging means together with the operation of the vertical moving means when the robot hand holds the wafer; FIG. 10 is an explanatory diagram showing, in graph form, an example of the value of the current flowing through the Z-axis motor when the robot hand holding the wafer rises by a predetermined distance; FIG. 10 is an explanatory diagram for explaining the work of judging whether the thickness of the wafer is normal or not, which is performed by the judging means together with the operation of the reversing moving means when the robot hand holds the wafer; FIG. 5 is an explanatory diagram showing, in graph form, an example of a value of current flowing through a reversing motor when reversing the robot hand after the robot hand holds a wafer; FIG. 10 is an explanatory view for explaining the operation of judging whether the thickness of the wafer is normal or not, which is performed by the judging means together with the operation of the X-axis moving means (horizontal moving means) after the robot hand holds the wafer; FIG. 5 is an explanatory diagram showing, in graph form, an example of the value of current flowing through an X-axis motor when a robot hand holding a wafer horizontally moves a predetermined distance;

A processing apparatus 1 according to the present invention shown in FIG. 1 is an apparatus for grinding a wafer W held on a chuck table 30 by a processing means 16. ) is an attachment/detachment area A where the wafer W is attached/detached to/from the chuck table 30 , and the rear side (+Y direction side) on the apparatus base 10 is the wafer W held on the chuck table 30 by the processing means 16 . This is a processing area B where grinding processing is performed.
The processing apparatus according to the present invention is not limited to a grinding apparatus in which the processing means 16 of the processing apparatus 1 has a single axis, but includes rough grinding means and finish grinding means. A two-axis grinding device or the like may be used in which W can be positioned below each grinding means. Further, the processing device may be a polishing device that polishes the wafer W by processing means having a polishing pad.

The wafer W is, for example, a circular semiconductor wafer made of a silicon base material or the like, and the surface Wa of the wafer W facing downward in FIG. , are protected by a protective tape (not shown). The back surface Wb of the wafer W facing upward is the surface to be ground. The wafer W may be made of gallium arsenide, sapphire, gallium nitride, ceramics, resin, silicon carbide, or the like other than silicon, or may be a rectangular package substrate or the like.

A first cassette stage 150 and a second cassette stage 151 are provided on the front side of the apparatus base 10 in the -Y direction. One cassette 21 is mounted, and the second cassette 22 accommodating the processed wafers W is mounted on the second cassette stage 151 .

Since the first cassette 21 and the second cassette 22 shown in FIG. 1 have the same configuration, only the first cassette 21 will be described below.
The first cassette 21 shown in detail in FIG. 2 has, for example, a bottom plate 210, a top plate 211, a rear wall 212, two side walls 213, and an opening 214 on the front side (+Y direction side). The wafer W can be carried in and out through the opening 214 . Inside the first cassette 21, a plurality of shelves 215 are formed at predetermined intervals in the vertical direction, and the wafers W can be accommodated one by one on the shelves 215. As shown in FIG. Note that the configuration of the first cassette 21 is not limited to this example.

As shown in FIGS. 1 and 2, in front of the opening 214 of the first cassette 21, the wafer W contained in the first cassette 21 placed on the first cassette stage 150 is held. A robot 4 for unloading from the cassette 21 is arranged.
The robot 4 is an articulated robot, and includes a robot hand 40 that holds the wafer W, a moving means 42 that moves the robot hand 40, and a robot hand 40 that holds the wafer W in a predetermined normal thickness. and a judgment means 44 for judging whether or not the thickness is sufficient.

The moving means 42 is, for example, a reversing moving means 45 that reverses and moves one surface 40a (hereinafter referred to as an attraction surface 40a) of the robot hand 40 and the other surface 40b (see FIG. 2) opposite to the attraction surface 40a. , vertical movement means 47 for moving the robot hand 40 in the vertical direction (Z-axis direction), and X-axis direction movement means shown in FIG. 2 for moving the robot hand 40 in the horizontal direction (X-axis direction) perpendicular to the vertical direction. 43 (that is, horizontal movement means 43), and turning movement means 48 (see FIG. 2) for turning the robot hand 40 in the horizontal direction (X-axis Y-axis plane) about a turning axis extending in the Z-axis direction. I have.

As shown in FIG. 2, the robot 4 includes, for example, a long plate-shaped first arm 421, a long plate-shaped second arm 422, and a cylindrical robot hand extending in the Z-axis direction. and an arm connecting portion 425 that connects the first arm 421 and the second arm 422 .

An upper surface of one end of the first arm 421 is connected to the robot hand connecting portion 423 . The upper surface of one end of the second arm 422 is connected to the lower surface of the other end of the first arm 421 via an arm connecting portion 425 . The lower surface of the other end of the second arm 422 is connected to a rotating shaft 433 that is rotatably housed inside an elevating casing 470 that constitutes the vertically moving means 47 .

As shown in FIG. 2, a pivoting movement means 48 is arranged within the device base 10 . The turning movement means 48 includes a turning motor 481 that generates driving force for rotating the lifting casing 470 with the center of the lifting casing 470 as a turning axis, a turning roller 483 connected to the shaft of the turning motor 481 , and the turning shaft of the lifting casing 470 . and a current control section 429 for controlling the current flowing through the turning motor 481 . A current control unit 429 electrically connected to the swing encoder 482 and the swing motor 481 by wiring (not shown) recognizes the rotation angle of the elevation casing 470 based on the rotation angle of the swing motor 481 recognized by the swing encoder 482, and recognizes the rotation angle of the lift casing 470. The turning position of the robot hand 40 can be recognized from the rotation angle, and the current flowing through the turning motor 481 can be controlled when the robot hand 40 moves to the set destination.
Note that the turning movement means 48 may be arranged inside the elevating casing 470 .

Further, as shown in FIG. 3, inside the elevator casing 470, an X-axis direction moving means for rotating a rotating shaft 433 coaxial with the turning shaft inside the elevator casing 470 to move the robot hand 40 in the X-axis direction is provided. 43 are provided. The X-axis direction moving means 43 moves the robot hand 40 in the X-axis direction (horizontal direction) by rotating the first arm 421 in conjunction with rotating the second arm 422 . The X-axis direction moving means 43 can horizontally move the robot hand 40 also in the Y-axis direction by rotating the robot hand 40 with the rotating movement means 48 to face the first cassette 21 . The robot 4 includes a pulley 422a on one end inside the second arm 422, a pulley 422b on the other end, and an endless belt 422c connecting the pulleys 422a and 422b. The robot 4 also includes a pulley 421a on one end inside the first arm 421, a pulley 421b on the other end, and an endless belt 421c connecting the pulleys 421a and 421b. Also, the pulley 422b and the pulley 421b are connected by a connecting shaft 422d. Also, the pulley 422a and the rotating shaft 433 are connected. Also, the pulley 421a and the robot hand connecting portion 423 are connected.

The X-axis direction moving means 43 controls an X-axis motor 431 that serves as a driving force source for rotating the rotating shaft 433 , an X-axis encoder 432 that recognizes the rotation angle of the rotating shaft 433 , and a current that flows through the X-axis motor 431 . At least a current control unit 429 is provided.
A current control unit 429 electrically connected to the X-axis encoder 432 and the X-axis motor 431 by wiring (not shown) recognizes the rotation angle of the rotary shaft 433 from the rotation angle of the X-axis motor 431 recognized by the X-axis encoder 432 . , the position of the robot hand 40 in the X-axis direction (or the position in the Y-axis direction) of the robot hand 40 is recognized from the recognized rotation angle, and the current flowing through the X-axis motor 431 when moving the robot hand 40 to the set destination is can be controlled.
When the rotation shaft 433 connected to the X-axis motor 431 is rotated, the second arm 422 is turned, and the turning of the second arm 422 turns the first arm 421 connected by the arm connection part 425, thereby turning the robot hand. 40 is moved horizontally. That is, the first arm 421 and the second arm 422 can be transformed from a crossed state to a straight line state.

For example, as shown in FIGS. 2 and 3, a vertically moving means 47 is arranged inside the device base 10 . The vertical movement means 47 includes an elevating casing 470, a Z-axis motor 471 that generates driving force for moving the robot hand 40 in the Z-axis direction, and a Z-axis encoder 472 that recognizes the height position of the robot hand 40 in the Z-axis direction. , and a current control unit 429 that controls the current flowing through the Z-axis motor 471 . The current control unit 429 recognizes the height position of the robot hand 40 from the rotation angle of the Z-axis motor 471 recognized by the Z-axis encoder 472, and operates the Z-axis motor 471 when moving the robot hand 40 to the set destination. can control the current flowing through

Further, inside the apparatus base 10, a Z-axis motor 471 is connected to a ball screw 473 having an axis in the Z-axis direction, a pair of guide rails 474 arranged parallel to the ball screw 473, and a nut inside the ball screw 473. The elevator casing 470 is connected to the elevator plate 475 via a bearing (not shown) and a gear (not shown). It is also connected to the turning roller 483 by, for example. When the Z-axis motor 471 rotates the ball screw 473, the elevating plate 475 is guided by the guide rail 474 to reciprocate in the Z-axis direction, and the elevating casing 470 connected to the elevating plate 475 also moves in the Z-axis direction. move back and forth.

The Z-axis encoder 472 detects the rotation angle of the rotation shaft of the Z-axis motor 471, and based on the rotation angle, the movement amount of the elevator plate 475 in the Z-axis direction, in other words, the movement amount of the robot hand 40 in the Z-axis direction. is calculated, the height position of the robot hand 40 can always be recognized. The Z-axis encoder 472 can transmit information about the recognized rotation angle of the Z-axis motor 471 , in other words, information about the recognized height position of the robot hand 40 to the electrically connected current control unit 429 . ing.

A current control unit 429 including a motor driver or the like is electrically connected to the Z-axis motor 471, and can control the amount of current flowing through the Z-axis motor 471 by supplying power from a driving power source (not shown). .

A reversing movement means 45 is arranged on the upper end side of the robot hand connecting portion 423 . The reversing movement means 45 includes, for example, a housing 451 that rotatably supports a spindle 450 having an axis in the X-axis direction perpendicular to the vertical direction (Z-axis direction) in FIG. For example, inside the housing 451, a reversing motor 454 that generates a driving force to reversely move the one surface 40a (suction surface 40a) and the other surface 40b of the robot hand 40 is arranged. A reversing encoder 456 is connected to the reversing motor 454. The reversing encoder 456 detects the rotation angle of the rotating shaft of the reversing motor 454, and determines whether the attraction surface 40a of the robot hand 40 moves vertically, for example, based on the rotation angle. You can always recognize which direction you are facing.

The reversing encoder 456 can transmit information about the recognized rotation angle of the reversing motor 454, in other words, information about the recognized orientation of the attracting surface 40a of the robot hand 40 to the electrically connected current control unit 429. there is The current control unit 429 is electrically connected to the reversing motor 454 and can control the amount of current flowing through the reversing motor 454 by supplying power from a drive power source (not shown). It is possible to control the current flowing through the reversing motor 454 when the orientation of the attraction surface 40a of the robot hand 40 is reversed upside down by the rotation angle of the reversing motor 454.

The tip side of the spindle 450 rotated by the driving force generated by the reversing motor 454 shown in FIG. 2 protrudes from the housing 451 in the +X direction. is set. As the reversing motor 454 rotates the spindle 450, the robot hand 40 connected to the spindle 450 via the support holder 452 rotates, and the attraction surface 40a of the robot hand 40 can be vertically inverted. .

The plate-shaped robot hand 40 that is mounted on the support holder 452 and holds the wafer W by suction includes, for example, a rectangular plate-shaped base portion 400 that is mounted on the support holder 452 and a substantially U-shaped base portion 400 integrally formed with the base portion 400 . and a suction portion 401 having a shape. Note that the robot hand 40 is not limited to the shape in this embodiment.

In FIGS. 1 and 2, the upward attracting surface 40a of the robot hand 40 is finished smooth. Further, the edge (ridge line) of the attraction surface 40a may be chamfered so as not to damage the wafer W when it comes into contact with it.

A plurality of suction holes 403 are opened in the adsorption surface 40a. For example, the suction holes 403 are opened at five locations in an area on the outer peripheral side of the attracting surface 40a at approximately equal intervals, three or four at each. Note that the number and locations of the suction holes 403 are not limited to this example.
A deformable rubber suction cup or the like may be provided in the suction hole 403 .

One end of a suction path 404 passing through the interior of the robot hand 40 communicates with each of the suction holes 403 , and the other end of the suction path 404 is made of flexible resin so as not to hinder the turning movement of the robot hand 40 . A tube 490 communicates via a joint (not shown) or the like. The other end of the resin tube 490 is connected to a suction source 49 such as a vacuum generator or an ejector mechanism. Although FIG. 2 shows the suction path 404 communicating with only one suction hole 403 , the other suction holes 403 are also communicated with the suction paths 404 .

Judgment means 44 for judging whether or not the thickness of the wafer W is a predetermined normal thickness with the robot hand 40 holding the wafer W shown in FIG. properly connected. The current control unit 429 outputs information about the value of the current flowing through the Z-axis motor 471, the information about the value of the current flowing through the reversing motor 454, and the information about the value of the current flowing through the X-axis motor 431. It can be transmitted to the comparison unit 440 . The determination unit 44 in this embodiment includes, for example, the current value comparison unit 440 and a storage unit 443 such as a memory.

As shown in FIG. 1, a temporary placement area 152 is provided adjacent to the robot 4, and an alignment means 153 is provided in the temporary placement area 152. As shown in FIG. The alignment means 153 aligns (centers) the wafer W unloaded from the first cassette 21 and placed on the temporary placement area 152 at a predetermined position with a diameter-reduced alignment pin.

A loading arm 154a that pivots while holding the wafer W is arranged at a position adjacent to the alignment means 153 . The loading arm 154a sucks and holds the wafer W aligned by the alignment means 153, and conveys it to the chuck table 30 disposed within the processing area B. As shown in FIG.

The chuck table 30 for sucking and holding the wafer W has, for example, a circular outer shape and includes a holding surface 300 made of a porous member or the like for sucking and holding the wafer W. As shown in FIG. The chuck table 30 is rotatable about a rotation axis whose axial direction is the Z-axis direction (vertical direction), and is surrounded by a cover 39. It can be reciprocated on the device base 10 in the Y-axis direction by a Y-axis direction moving means (not shown) disposed under the expandable bellows cover 39a.

A column 100 is erected on the rear side (+Y direction side) of the device base 10, and on the front surface of the column 100, a processing feed means 17 for processing and feeding the processing means 16 in the Z-axis direction is arranged. ing. The processing feed means 17 includes a ball screw 170 having an axis in the Z-axis direction, a pair of guide rails 171 arranged parallel to the ball screw 170, a motor 172 connected to the ball screw 170 to rotate the ball screw 170, and an internal A nut is screwed onto the ball screw 170 and the side portion is in sliding contact with the guide rail 171. A holder 174 is connected to the elevating plate 173 and holds the processing means 16. A motor 172 rotates the ball screw 170. As a result, the elevating plate 173 is guided by the guide rail 171 to reciprocate in the Z-axis direction, and the processing means 16 supported by the holder 174 also reciprocates in the Z-axis direction.

The processing means 16 for processing the wafer W carried out by the robot 4 and held on the chuck table 30 rotates the rotary shaft 160 whose axial direction is the Z-axis direction orthogonal to the holding surface 300 of the chuck table 30 and the rotary shaft 160. A housing 161 that supports the rotary shaft 160, a motor 162 that rotationally drives the rotary shaft 160, a mount 163 that is attached to the lower end of the rotary shaft 160, and a grinding wheel 164 that is detachably connected to the mount 163. The grinding wheel 164 includes a wheel base and a plurality of grinding wheels having a substantially rectangular parallelepiped outer shape and arranged in a plurality of rings on the lower surface of the wheel base.

At a position adjacent to the chuck table 30 positioned below the processing means 16, for example, a thickness measuring means 38 for measuring the thickness of the wafer W held by the chuck table 30 during grinding in a contact manner. are arranged.

The wafer W ground by the processing means 16 is unloaded from the chuck table 30 by the unloading arm 154b arranged in the loading/unloading area A. As shown in FIG.

As shown in FIG. 1, at a position close to the unloading arm 154b in the loading/unloading area A, there is a single-wafer type washing machine for cleaning the upward-facing rear surface Wb of the processed wafer W conveyed by the unloading arm 154b. A spinner cleaning mechanism 156 is provided. The spinner cleaning mechanism 156 holds the front surface Wa of the wafer W facing downward on a spinner table 156a, and sprays cleaning water onto the back surface Wb of the wafer W from a cleaning nozzle 156b that moves above the held wafer W. to wash the rear surface Wb.
The wafer W that has been cleaned and, for example, spin-dried by the spinner cleaning mechanism 156 is carried into the second cassette 22 by the robot 4 .

The operation of the processing apparatus 1 shown in FIG. 1 when grinding the wafer W held on the chuck table 30 will be described below.
As shown in FIG. 2, in the first cassette 21, the front surface Wa of the wafer W faces downward, for example. Then, for example, in order for the suction surface 40a of the robot hand 40 to suck and hold the front surface Wa of the wafer W facing downward, the spindle 450 is rotated to set it to face upward (+Z direction side). be done.

For example, the robot hand 40 shown in FIG. 2 is positioned at a height position Z1 recognized by the Z-axis encoder 472. As shown in FIG. The robot hand 40 at this height position Z1 is moved into the first cassette 21 . That is, the turning movement means 48 turns the robot hand 40, and the X-axis direction movement means 43 (horizontal movement means 43) moves the robot hand 40 horizontally so that the robot hand 40 moves toward the opening of the first cassette 21. 214 to a predetermined position inside the first cassette 21, and the robot hand 40 is positioned at a predetermined position in the horizontal plane, for example, so that the center of the robot hand 40 and the center of the wafer W substantially coincide with each other. be done.

After that, the robot hand 40 is raised from the height position Z1 to the height position Z3 shown in FIG. At that time, the robot hand 40 passes through the height position Z2 (the height position Z2 of the shelf 215 where the target wafer W is stored). When passing the height position Z2, the wafer W is sucked and held by the suction surface 40a of the robot hand 40 to which the suction force generated by the suction source 49 is transmitted. For example, when the robot hand 40 is raised from the height position Z1 to the height position Z2, the value of the current flowing through the Z-axis motor 471 is controlled by the current control unit 429 by supplying power from a driving power source (not shown). is the current value CV1 (see FIG. 5).

Then, in the next step, it is determined whether or not the thickness of the wafer W is normal by the determining means 44, which will be described below. The judgment by the judging means 44 may be made at a stage when the robot hand 40 sucking and holding the wafer W is in the first cassette 21 as in the example shown in FIG. , that is, at the stage where the robot hand 40 sucking and holding the wafer W shown in FIG.
In addition, in FIG. 4, each structure of the up-and-down movement means 47 and the reversing movement means 45 is simplified and shown.

When the judgment means 44 makes a judgment, for example, the robot hand 40 is lifted in the +Z direction by the vertical movement means 47 shown in FIG. It is positioned at the height position Z3. A current controller 429 controls the amount of current flowing through the Z-axis motor 471 when the weight of the wafer W is applied to the robot hand 40 . That is, the current value of the Z-axis motor 471 when moving from the height position Z2 to the height position Z3 is the same as that of the robot hand 40 when the robot hand 40 is raised from the height position Z1 to the height position Z2. The current value CV2 indicated by the bar graph G1 in FIG. In order to move the robot hand 40 while maintaining a predetermined speed both before and after holding the wafer W, the load acting on the Z-axis motor 471 causes the robot hand 40 to hold the wafer W. This is because the Z-axis encoder 472 and the current control unit 429 feedback-control the Z-axis motor 471 so that it rotates at a constant number of revolutions even when the rotation speed increases.
It should be noted that the current values shown in FIG. 5 indicate current values when the Z-axis motor 471 completes acceleration and operates at a constant speed. It should be noted that the determination may be made based on the current value during the acceleration operation.

The current control unit 429 shown in FIG. 4 transmits information about the current value CV2 of the current flowing through the Z-axis motor 471 to the determination means 44 .
For example, in the storage unit 443 of the determination unit 44, the robot hand 40 sucking and holding a wafer W of normal weight is controlled by the current control unit 429 and the Z-axis motor 471 is driven while the robot hand 40 is ascending at a predetermined speed. An upper limit value CV3 and a lower limit value CV4 (see FIG. 5) are stored for the flowing current value. As a result, the upper limit value CV3 to the lower limit value CV4, which are the predetermined range for the value of the current flowing through the Z-axis motor 471, are set in the determination means 44 in advance. The predetermined range, that is, the upper limit value CV3 to the lower limit value CV4, is a range determined by data obtained from past experiments.
A wafer W of normal weight is neither too thick nor too thin, and has a thickness within a predetermined range for proper grinding, and has no chipping on the outer peripheral edge or the like. There is no wafer.

A current value comparison unit 440 of the determination means 44 shown in FIG. CV4) is entered or not. 5, the current value CV2 that is controlled by the current control unit 429 and flows through the Z-axis motor 471 is between the upper limit value CV3 and the lower limit value CV4. , the held wafer W is judged to have a normal thickness. When the determining means 44 determines that the wafer W has a normal thickness, the robot 4 transports the wafer W to the temporary placement area 152 so as to transport the wafer W to the chuck table 30 shown in FIG. 1 for processing. do.

For example, when the robot hand 40 holding the wafer W shown in FIG. is the current value CV5 indicated by the bar graph G2 in FIG. In this case, the current value comparator 440 shown in FIG. It is determined that the value is below the value CV4. Then, the determination means 44 determines that the wafer W has an abnormal thickness, that is, that the wafer W is too thin than the normal thickness, or that the wafer W is chipped, for example, at the outer peripheral edge thereof. .

In this case, the robot 4 notifies the operator of the determination by, for example, sounding an alarm sound from a speaker attached to the processing apparatus 1 shown in FIG. 1 or displaying an error on the monitor. For example, the operator removes the wafer W having chipping from the robot hand 40 as not being a product. Alternatively, the processing apparatus 1 may be provided with a pick-up table within the movable range of the robot 4 on which the unproductive wafers W are placed, and the robot 4 may transfer the unproductive wafers W to the pick-up table.

For example, when the robot hand 40 holding the wafer W shown in FIG. is the current value CV6 indicated by the bar graph G3 in FIG. In this case, current value comparator 440 shown in FIG. It is determined that the value CV3 is exceeded. Then, the determination means 44 determines that the wafer W has an abnormal thickness, that is, the wafer W is thicker than a predetermined normal thickness.

In this case, the robot 4 notifies the operator of the determination by, for example, sounding an alarm or displaying an error. After the determination is made by the determination means 44, the wafer W determined to be too thick is returned to the first cassette 21 by the robot 4 shown in FIGS. Then, the operator can grasp the position (stage number) of the shelf 215 of the first cassette 21 in which the wafer W that is too thick is accommodated. For example, the storage unit 443 of the robot 4 may store the stage number of the shelf 215 of the first cassette 21 containing wafers W that are too thick.
After that, the wafer W that is too thick can be appropriately ground by changing the processing conditions for the wafer W set in the processing apparatus 1 .

As described above, when the determining means 44 determines that the wafer W has a normal thickness, the robot 4 shown in FIG. 1 moves the wafer W to the temporary placement area 152 . After the wafer W is centered on the temporary placement area 152 by the positioning means 153 , the loading arm 154 a carries the centered wafer W onto the chuck table 30 . Then, a suction source (not shown) is activated, and the chuck table 30 sucks and holds the wafer W with the rear surface Wb exposed upward.

The chuck table 30 sucking and holding the wafer W moves in the +Y direction, the center of rotation of the grinding wheel 164 of the processing means 16 is horizontally displaced from the center of rotation of the wafer W by a predetermined distance, and the rotation trajectory of the grinding wheel 164 shifts. A chuck table 30 is positioned at a predetermined position so as to pass through the center of rotation of the wafer W. As shown in FIG.

The processing means 16 is fed in the -Z direction by the processing feeding means 17, and the grinding wheel 164 is brought into contact with the rear surface Wb of the wafer W to perform the grinding process. During grinding, the wafer W rotates as the chuck table 30 rotates, so the grinding wheel 164 grinds the entire back surface Wb of the wafer W. FIG. Grinding water is supplied to the contact point between the grinding wheel 164 and the back surface Wb of the wafer W, and the contact point is cooled by the grinding water and the grinding dust is washed away.

While the thickness of the wafer W is measured by the thickness measuring means 38, after the wafer W is ground to a desired thickness, the processing feeding means 17 shown in FIG. , the grinding of the wafer W is completed.

Next, the chuck table 30 holding the wafer W by suction is moved in the -Y direction and positioned in the vicinity of the unloading arm 154b. Then, the unloading arm 154b shown in FIG. 1 carries the wafer W on the chuck table 30 to the spinner cleaning mechanism 156. As shown in FIG. After the spinner cleaning mechanism 156 cleans and dries the wafer W, the robot 4 loads the wafer W into the second cassette 22 .

As described above, in the processing apparatus 1 according to the present invention, the robot 4 includes the robot hand 40 that holds the wafer W, the vertical movement means 47 that vertically moves the robot hand 40, and the wafer W held by the robot hand 40. The vertical movement means 47 includes a Z-axis motor 471 that generates driving force for moving the robot hand 40 up and down, and the wafer W. and a current control unit 429 for controlling the electric power supplied to the Z-axis motor 471 when the robot hand 40 held thereon is raised. The value of the current that flows through the Z-axis motor 471 controlled by the current control unit 429 when moving from the recognized height position Z2 to the height position Z3 at a predetermined speed is within a predetermined range (for example, upper limit value CV3 to lower limit value CV4), it is determined that the held wafer W has a normal thickness, and the wafer W is transferred to the chuck table 30 and processed, and the current value is within a predetermined range set in advance. (within the upper limit value CV3 to the lower limit value CV4), by determining that the held wafer W has an abnormal thickness, for example, when the robot 4 holds the wafer W in the first cassette 21, Abnormalities in the thickness of the wafer W can be noticed. Therefore, the wasteful operation of transferring the wafer W with the abnormal thickness to the chuck table 30 can be eliminated, and the working efficiency can be improved.

The above determination by the determining means 44 is performed at the stage when the robot hand 40 sucking and holding the wafer W shown in FIG. Although the judgment time is slightly delayed, it is possible to judge the abnormal thickness of the wafer W with higher accuracy.

As shown in FIG. 6, the judgment of whether the thickness of the wafer W is normal or not by the judging means 44 may be made by using the reversing means 45 instead of the vertical moving means 47 . The thickness abnormality determination of the wafer W by the determination means 44 using the reversing movement means 45 is performed by the robot hand 40 sucking and holding the wafer W as described above, and then the robot hand 40 picks up the wafer W from the first cassette 21 . is carried out as shown in FIG. 6, and the robot hand 40 can be reversely moved.

The judgment means 44 determines that the robot hand 40, whose attraction surface 40a is oriented in the +Z direction to hold the wafer W, is rotated by, for example, 180 degrees by the reversing movement means 45 shown in FIG. - This is done until it is facing the Z direction. Note that the rotation angle of the reversing motor 454 for determination (hereinafter referred to as rotation angle θ2) is not limited to 180 degrees. For example, it may be determined when rotating by 90 degrees.

Here, for example, assuming that the wafer W is not held by suction, when the robot hand 40 is reversely moved to the rotation angle θ2 (180 degrees) of the reversing motor 454 recognized by the reversing encoder 456, a drive (not shown) is performed. The value of the current flowing through the reversing motor 454 due to the supply of power from the power source is the current value CV7 (see FIG. 7) controlled by the current control section 429 .

On the other hand, as shown in FIG. 6, when the reversing motor 454 rotates until the rotation angle θ2 recognized by the reversing encoder 456 becomes 180 degrees due to the weight of the wafer W held by the robot hand 40, the reversing motor 454 The amount of current that flows is controlled by the current control unit 429 and becomes a current value CV8 indicated by the bar graph G4 in FIG. 7, which is greater than the current value CV7 when the robot hand 40 does not hold the wafer W.

The current control unit 429 shown in FIG. 6 transmits information about the current value CV8 of the current flowing through the reversing motor 454 to the determination means 44 .
For example, in the storage unit 443 of the determination means 44, the robot hand 40 sucking and holding the wafer W of normal weight increases until the rotation angle of the reversing motor 454 reaches the rotation angle θ2 (180 degrees). An upper limit value CV9 and a lower limit value CV10 (see FIG. 7) are stored for the value of the current that is controlled by the current control unit 429 and flows through the reversing motor 454 according to the weight of the wafer W. As a result, the upper limit value CV9 to the lower limit value CV10, which are the predetermined range of the current value flowing through the reversing motor 454, are set in the determination means 44 in advance. The upper limit value CV9 to lower limit value CV10, which is the predetermined range, is a range determined by data obtained from past experiments.

The current value comparison unit 440 of the judgment means 44 shown in FIG. inside) is compared whether it enters or not. As shown in the bar graph G4 of FIG. 7, the current value CV8 that is controlled by the current control unit 429 and flows through the reversing motor 454 is within the upper limit value CV9 and the lower limit value CV10. It is determined that the held wafer W has a normal thickness. When the determining means 44 determines that the wafer W has a normal thickness, the robot 4 transports the wafer W to the temporary placement area 152 so as to transport the wafer W to the chuck table 30 shown in FIG. 1 for processing. do.

For example, in order to reverse the robot hand 40 holding the wafer W shown in FIG. Assume that the information sent from the current control unit 429 regarding the current value of the current is the current value CV11 indicated by the bar graph G5 in FIG. In this case, the current value comparison unit 440 determines that the current value CV11 of the current flowing through the reversing motor 454 does not fall within the predetermined range from the upper limit value CV9 to the lower limit value CV10 and falls below the lower limit value CV10. judge that there is Then, the judgment means 44 judges that the wafer W is too thin than the normal thickness, or that the wafer W is chipped, for example, at the outer peripheral edge thereof.

In this case, the robot 4 notifies the operator of the determination by warning or error display. For example, the operator removes the wafer W or the like having chippings from the robot hand 40 as not being a product. Alternatively, the processing apparatus 1 may transfer the non-product wafers W to a pick-up table on which the non-product wafers W are placed.

For example, in order to reverse the robot hand 40 holding the wafer W shown in FIG. Assume that the information is the current value CV12 indicated by the bar graph G6 in FIG. In this case, current value comparison section 440 shown in FIG. It is determined that CV9 is exceeded. Then, the determination means 44 determines that the wafer W is thicker than the predetermined normal thickness.

In this case, the robot 4 notifies the operator of the determination by, for example, sounding an alarm or displaying an error. After the determination is made by the determination means 44, the wafer W determined to be too thick is returned to the first cassette 21 by the robot 4 shown in FIGS. After that, the wafer W that is too thick can be appropriately ground by changing the processing conditions for the wafer W set in the processing apparatus 1 .

As described above, when the determining means 44 determines that the wafer W has a normal thickness, the robot 4 shown in FIG. 1 moves the wafer W to the temporary placement area 152 . Then, the wafer W is ground by performing the same process as the process described above.

As described above, in the processing apparatus 1 according to the present invention, the robot 4 includes the robot hand 40 holding the wafer W, the reversing movement means 45 for reversing the robot hand 40, and the wafer W held by the robot hand 40. The reversing movement means 45 includes a reversing motor 454 that generates driving force for reversing the robot hand 40, and a wafer W holding and a current control unit 429 for controlling power supplied to the reversing motor 454 when the robot hand 40 is reversely moved. When the reversing motor 454 is rotated at a predetermined reversing movement speed until the rotation angle of the reversing motor 454 reaches the rotation angle θ2, the value of the current that flows through the reversing motor 454 controlled by the current control unit 429 is set within a predetermined range. If it is within (for example, within the upper limit value CV9 to the lower limit value CV10), it is determined that the held wafer W has a normal thickness, and the wafer W is transferred to the chuck table 30 and processed, and the current value is set in advance. If the thickness is out of the predetermined range (within the upper limit value CV9 to the lower limit value CV10), it is determined that the held wafer W has an abnormal thickness. After removing the wafer W, the robot hand 40 is reversely moved. The useless operation of transferring the wafer W to the chuck table 30 can be eliminated, and the working efficiency can be improved.

For example, the determination of whether or not the thickness of the wafer W is normal by the determining means 44 may be performed using the X-axis direction moving means 43 as shown in FIG. The thickness abnormality determination of the wafer W by the determination means 44 using the X-axis direction moving means 43 is performed after the robot hand 40 sucks and holds the wafer W as described above. This is performed when the wafer W is unloaded from the inside as shown in FIG. That is, for example, by moving the robot hand 40 from the position Y1 shown in FIG. 8 to the position Y2, the first arm 421 and the second arm 422 shown in FIG. (a state in which the arms are extended and the robot hand 40 is in the first cassette 21) is transformed into a state in which they cross each other (a state in which the arms are folded and shortened and the robot hand 40 is out of the first cassette 21). Thickness abnormality determination is performed when

Here, for example, assuming that the robot hand 40 does not hold the wafer W by suction, when the robot hand 40 moves from position Y1 to position Y2 shown in FIG. The value of the current flowing through the X-axis motor 431 is controlled by the current control unit 429 when the drive power source supplies power to rotate the X-axis motor 431 when the X-axis motor 431 moves a predetermined distance at a predetermined speed. CV13 (see FIG. 9).

On the other hand, as shown in FIG. 8, when the X-axis motor 431 rotates to move the robot hand 40 holding the wafer W from the position Y1 to the position Y2 at a predetermined speed, the current flowing through the X-axis motor 431 is The amount of current is controlled by the current control unit 429 and becomes a current value CV14 indicated by the bar graph G7 in FIG. 9, which is greater than the current value CV13 when the robot hand 40 does not hold the wafer W.

The current control unit 429 shown in FIG. 8 transmits information about the current value CV14 of the current flowing through the X-axis motor 431 to the determination means 44 .
For example, in the storage unit 443 of the determination means 44, the robot hand 40 sucking and holding the wafer W of normal weight is controlled by the current control unit 429 while it moves from the position Y1 to the position Y2 at a predetermined speed. An upper limit value CV15 and a lower limit value CV16 (see FIG. 9) of the current value flowing through the X-axis motor 431 are stored. As a result, the upper limit value CV15 to the lower limit value CV16, which are the predetermined range of the current value flowing through the X-axis motor 431, are set in the determination means 44 in advance. The upper limit value CV15 to the lower limit value CV16, which is the predetermined range, is a range determined by data obtained from past experiments.

A current value comparison unit 440 of the determination means 44 shown in FIG. 8 determines whether or not the current value CV14 of the current flowing through the X-axis motor 431 falls within a preset predetermined range (within the upper limit value CV15 and the lower limit value CV16). compare. 9, the current value CV14 that is controlled by the current control unit 429 and flows through the X-axis motor 431 is between the upper limit value CV15 and the lower limit value CV16. , the held wafer W is judged to have a normal thickness. Then, the robot 4 transports the wafer W to the temporary placement area 152 so that the wafer W is transported to the chuck table 30 shown in FIG. 1 and processed.

For example, when the X-axis motor 431 rotates to horizontally move the robot hand 40 holding the wafer W shown in FIG. Assume that the information about the current value of the flowing current is the current value CV17 indicated by the bar graph G8 in FIG. In this case, the current value comparison unit 440 determines that the current value CV17 of the current flowing through the X-axis motor 431 does not fall within the predetermined range from the upper limit value CV15 to the lower limit value CV16 and falls below the lower limit value CV16. It is determined that Then, the determination means 44 determines that the wafer W is too thin than the normal thickness, or the wafer W is chipped, for example, at the outer peripheral edge thereof, so that the load current value of the X-axis motor 431 is higher than normal. judged to be lower. In this case, the robot 4 notifies the operator of the determination by warning or error display. For example, the operator removes the wafer W or the like having chippings from the robot hand 40 as not being a product. Alternatively, the processing apparatus 1 may transfer the non-product wafers W to a pick-up table on which the non-product wafers W are placed.

For example, when the X-axis motor 431 rotates to horizontally move the robot hand 40 holding the wafer W shown in FIG. Assume that the information about the current value of the flowing current is the current value CV18 indicated by the bar graph G9 in FIG. In this case, the current value comparator 440 shown in FIG. It is determined that the value CV15 is exceeded. Then, the judgment means 44 judges that the load current value of the X-axis motor 431 has become larger than normal because the wafer W is thicker than a predetermined normal thickness.

In this case, the robot 4 notifies the operator of the determination by, for example, sounding an alarm or displaying an error. After the determination is made by the determination means 44, the wafer W determined to be too thick is returned to the first cassette 21 by the robot 4 shown in FIGS. After that, the wafer W that is too thick can be appropriately ground by changing the processing conditions for the wafer W set in the processing apparatus 1 .

As described above, when the determining means 44 determines that the wafer W has a normal thickness, the robot 4 shown in FIG. 1 moves the wafer W to the temporary placement area 152 . Then, the wafer W is ground by performing the same process as the process described above.

As described above, in the processing apparatus 1 according to the present invention, the robot 4 includes the robot hand 40 that holds the wafer W, the horizontal movement means 43 (X-axis direction movement means 43) that horizontally moves the robot hand 40, and the robot a judgment means 44 for judging whether the thickness of the wafer W held by the hand 40 is a predetermined normal thickness, and the horizontal movement means 43 generates a driving force for horizontally moving the robot hand 40. It comprises an axis motor 431 and a current control section 429 for controlling electric power supplied to the X-axis motor 431 when the robot hand 40 holding the wafer W is moved horizontally. When the X-axis motor 431 is rotated to horizontally move the robot hand 40 from position Y1 to position Y2, the value of the current that flows through the X-axis motor 431 controlled by the current control unit 429 is within a predetermined range. If it is within (for example, within the upper limit value CV15 to the lower limit value CV16), it is determined that the held wafer W has a normal thickness, and the wafer W is transferred to the chuck table 30 and processed, and the current value is set in advance. For example, the robot 4 holds the wafer W from the first cassette 21 by determining that the held wafer W has an abnormal thickness if it is out of the predetermined range (within the upper limit value CV15 to the lower limit value CV16). Even if the thickness of the wafer W is abnormal and different from the normal thickness of the wafer W, the abnormality of the thickness can be noticed when the wafer W is removed from the chuck table 30. It is possible to eliminate the wasteful operation of conveying, and improve work efficiency.

It goes without saying that the processing apparatus 1 according to the present invention is not limited to the above embodiment, and may be implemented in various forms within the scope of the technical idea. Moreover, the shape and the like of each component of the processing apparatus 1 shown in the accompanying drawings are not limited to this, and can be changed as appropriate within the range in which the effects of the present invention can be exhibited.

W: Wafer 1: Processing device 10: Device base A: Detachable region B: Processing region 100: Column 150: First cassette stage 21: First cassette 214: Opening 215: Shelf 151: Second cassette stage 22 : second cassette 152: temporary placement area 153: positioning means 154a: loading arm 154b: unloading arm
4: Robot 40: Robot hand 40a: Adsorption surface 400: Base 401: Suction part 403: Suction hole 404: Suction path 490: Resin tube 49: Suction source 42: Moving means 421: First arm 422: Second arm 423: Robot hand connecting section 425: Arm connecting section 429: Current control section 43: X-axis direction moving means 431: X-axis motor 432: X-axis encoder 47: Vertical moving means 470: Elevating casing 471: Z-axis motor 472: Z Shaft encoder 473: Ball screw 474: Pair of guide rails 475: Elevating plate 45: Reversing movement means 450: Spindle 451: Housing 452: Holder 454: Reversing motor 456: Reversing encoder 44: Judging means 440: Current value comparing unit 443: Storage Part 48: turning movement means 481: turning motor 482: turning encoder 483: turning roller 30: chuck table 300: holding surface 16: processing means 17: processing feeding means 38: thickness measuring means

Claims (4)

A cassette having a shelf capable of storing a plurality of wafers, a cassette stage on which the cassette is placed, a robot that holds the wafers stored in the cassette placed on the cassette stage and unloads the wafer from the cassette, and the robot and a processing means for processing the wafer carried out by and held on the chuck table,
The robot includes a robot hand holding a wafer, a moving means for moving the robot hand, a determination means for determining whether the thickness of the wafer held by the robot hand is a predetermined normal thickness, with
The moving means includes a motor that generates driving force for moving the robot hand, and a current control section that controls current flowing through the motor,
The judgment means holds the wafer if the value of the current that flows through the motor controlled by the current control unit when the robot hand holds the wafer and drives the motor is within a preset range. If it is judged that the wafer has a normal thickness, the wafer is transported to the chuck table and processed, and if the value of the current is out of the preset range, the held wafer has an abnormal thickness. Processing equipment that determines that 2. The processing apparatus according to claim 1, wherein said moving means is reversing moving means for reversing one surface and the other surface of said robot hand. 2. The processing apparatus according to claim 1, wherein said moving means is vertical moving means for moving said robot hand in a vertical direction. 2. The processing apparatus according to claim 1, wherein said moving means is horizontal moving means for horizontally moving said robot hand.

Images