JPH11307489A - Grinding equipment of wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make equipment compact by making only one robot arm, by installing a vertical type accommodation cassette of wafers at an annular position of the same shaft center as the shaft of a robot arm, installing a temporary mount stand of wafers and a cleaning unit on both sides of the shaft, and installing apparatuses of wafer grinding behind the shaft. SOLUTION: In front of a shaft 3 of a robot arm 4, vertical type accommodation cassette 5, 5' are installed at annular positions of the same shaft center as the shaft 3. A temporary mount stand 6 of wafers in the case of cleaning is installed on the left side of the shaft 3. A cleaning unit 10 for wafers are installed on the right side of the shaft 3. An index table 13 supporting releasably a grinding table 12 is installed behind the shaft 3. Facing the table 13, a grinding table cleaning machine 15 is fixed to a rail 14 movably in the lateral direction. Behind the cleaning table 15, a grinding machine 16 is installed, which is constituted by installing a rough grinding machine and a finish grinding machine 16d to a frame 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for grinding a wafer such as a bare wafer, a wafer with devices, and a magnetic disk wafer.

[0002]

2. Description of the Related Art As a method for grinding a semiconductor wafer, for example, a grinding apparatus shown in FIG. 6 is used, and a plurality of wafers A are stacked and stored in a ladder-shaped partition frame for each product, and the cassette is movable up and down and has an open front surface. The wafer A on the transfer belt is guided and placed on a transfer belt 50 provided on the lower side immediately before the transfer belt 5, and a reversing arm 60 with a suction pad that rotates vertically between the transfer belts. The wafer is moved to the pre-position device 70, the position is adjusted at the pre-position, the wafer A can be moved up and down from the pre-position, and the lower surface of the suction pad 80a provided at the tip of the wafer moving arm 80 having a horizontal turning mechanism is provided. Vacuum is adsorbed and moves onto the rotary index table 13 of the grinding device 1.

The rotary index table 13 is provided with a circular vacuum chucking mechanism 12 which rotates by itself, and the rotary index table automatically repeats rotation and stop. A spindle shaft (not shown) provided with a grinding wheel or the like is lowered to a tip provided on an index head provided above the mechanism 12 to perform predetermined processing such as grinding on each chuck mechanism 12. It is.

The wafer A is set on the chuck mechanism 12 by the wafer moving arm 80 and is vacuum-sucked to the chuck mechanism 12. The wafer A is rotated together with the chuck mechanism 12 by rotating the rotary index table 13. Moves to the next machining position,
Grinding or the like is performed sequentially from rough grinding to finish grinding to a predetermined required thickness, and the processing is completed.

[0005] Finally, the cleaning and drying apparatus 10 cleans and dries the sheet, places it on the storage conveyor belt 90, and puts the cassette into the ladder-shaped partition frame provided on the side wall of the storage cassette 5 '. It is integrated and stored again for each single product by elevating. (JP-A-2-193815, JP-A-2-1938)
No. 16, JP-A-4-53661). The high integration of ICs is shifting from 64 Mbits to 256 Mbits, and it is predicted that 1 Gbits will be reached in the early 21st century. In order to cope with such a high integration, a multilayer structure of a device is progressing, and it is becoming difficult to focus at the time of exposure due to unevenness of the device surface.

[0006] For this reason, it is desired that the surface of the wafer is flattened, and during the grinding, polishing, and chemical mechanical polishing of the wafer, grinding chips and polishing chips of the wafer in the preceding process adhere to the grinding table and the wafer, and are ground and polished. In order to prevent the flatness of the wafer from deteriorating, the surface of the wafer and the grinding table are cleaned before and after processing. Therefore, incorporating these cleaning apparatuses into a conventional wafer grinding apparatus requires an increase in the size and size of the grinding apparatus, and a more compact apparatus. Also, it is necessary to ensure the safety of the operator of the grinding device when the device is operated.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a compact wafer grinding apparatus which ensures the safety of a worker when the apparatus is operated.

[0008]

SUMMARY OF THE INVENTION A first aspect of the present invention is to provide a robot arm 4 which is mounted on a base 2 in a vertically movable and rotatable manner so as to be horizontally expandable and contractible and rotatable. A vertical storage cassette 5, 5 ′ for a plurality of wafers provided at an annular position having a center point of the same circle as the axis of the shaft 3, provided on the front side of the shaft 3, A temporary mounting table 6 for a wafer capable of cleaning the back surface of the provided wafer with water, and a suction chuck supported on a vertically movable shaft 7 provided on the right side of the shaft 3 opposite to the temporary mounting table 6 for the wafer. A mechanism 8 and a plate 9 capable of supplying water around the chuck mechanism
Cleaning apparatus 10 provided with the above, an index table 13 provided with three rotatable grinding tables 12 mounted at a rotatable shaft 11 provided on the rear side of the shaft 3 of the robot arm and provided at equal intervals from the shaft 11 , The index table 1
3. A grinding table cleaning device mounted on the rail 14 so as to be able to run laterally with a pair of a rail 14 provided on the index table 3 and a brush cleaning device 15a and a chuck cleaner 15b provided oppositely on an index table. 1
5. A frame on which a rough grinding machine 16b mounted on a rotating shaft 16a and a finish grinding machine 16d mounted on a rotating shaft 16c are installed above the index table 13 and behind the grinding table cleaning machine 15. 21 is provided.

A second aspect of the present invention is that a base 2 of the above-mentioned wafer grinding apparatus 1 has a semicircular truncated front, and a semicircular rail 2a.
Is provided on the upper surface of the base 2 on the front side of the vertical storage cassettes 5 and 5 'for a plurality of wafers, and a wafer grinding apparatus 1 provided with a double door safety door 18 movable on this rail. Is provided.

[0010]

The vertical storage cassettes 5 and 5 'for a plurality of wafers are provided at the front of the shaft 3 of the robot arm at an annular position having the same center point of the circle as the axis of the shaft 3. By providing a temporary wafer mounting table 6 and a wafer cleaning device (spinner device) 10 on both lateral sides, only one robot arm 4 for transferring the wafer is required, and a wafer grinding process is performed on the rear surface of the shaft 3. Since the index table 13, the grinding table cleaning device 15, and the grinding devices 16b and 16d are provided, the device is more compact than a conventional grinding device using two robot arms.

Further, since the base 2 can be formed into a semicircular trapezoidal shape by the above-described installation (layout), the semicircular rail 2a is connected to the vertical storage cassette 5 for a plurality of wafers. By providing the safety door 18 on the front surface of the base 5 'on the upper surface of the base 2 and movable on this rail, the safety door 18 can be further secured. Since the double door travels left and right on a semicircular rail, the width of the device is narrower than that of a conventional safety door that travels in the horizontal direction (it is necessary to provide a play rail in the horizontal direction). can do.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG.
Is a top view of the grinding apparatus 1 of the present invention, FIG. 2 is a front view of the grinding apparatus, FIG. 3 is a perspective view showing a main part of the grinding apparatus, FIG. 4 is a cross-sectional view of a temporary mounting table, and FIG. FIG. 5 is a plan view showing the arm tip of FIG.

1 to 3, 1 is a wafer grinding device, 2 is a base, 3 is a vertically movable and rotatable shaft, and 4 is mounted on the shaft 3 so as to be horizontally stretchable and rotatable. The robot arms 5, 5 'are provided in front of the shaft 3 and have a plurality of vertical storage cassettes for wafers provided at an annular position having a center point of the same circle as the axis of the shaft 3.
Is a temporary mounting table of a wafer capable of cleaning the back surface of the mounted wafer with water, 7 is a vertically movable shaft, 8 is a suction chuck mechanism supported on the shaft 7, and 9 is provided around the chuck mechanism 8. A porous ceramic plate capable of supplying water, 10 is a wafer cleaning device (spinner device), 11 is a rotatable shaft, 12,
Reference numerals 12 and 12 denote a horizontally rotatable grinding table supported by a rotating shaft, 13 denotes an index table supported by a shaft 11, 14 denotes a rail, and 15 denotes a grinding table washing machine provided on the upper surface of the index table. This is configured as a pair of a brush cleaner 15a and a chuck cleaner 15b for the grinding table 12, and is attached to the rail 14 so as to be movable in the lateral direction. 16
Is a grinding machine mounted on a shaft which can be moved up and down, and a rough grinding machine 16b supported on a rotating shaft 16a;
c and a finish grinding machine 16d which is mounted on the machine.
These grinding machines 16b and 16d are installed on the frame 21.

The suction pads 17, 17 'are provided to reduce the work load of the robot arm 4 if necessary, and are a wafer transfer mechanism rotatable about a shaft 17b having a suction pad 17a. , 17 are used to transfer the wafer on the temporary table 6 onto the grinding table 12,
17 'is used to transfer the wafer on the grinding table 12 to the suction chuck mechanism of the wafer cleaning apparatus 10.
These operations may be performed by the robot arm 4.

Reference numeral 18 denotes a double-doored safety door, which is provided with handles 18a, 18a on the front surface thereof, and is formed in an arc shape on the rail 2a on the semicircular trapezoidal upper surface of the front portion of the base 2 around the shaft 18b. It can be opened and closed. 19 is a control monitor, 20
Is a housing. In FIG. 4, the temporary mounting table 6 has a structure including a porous ceramic plate 63 held above a frame body 62 having a water introduction nozzle 61 and a universal joint 65. The adsorbed wafer A is placed on the temporary mounting table 6 or supplied from the water introduction nozzle 61, and the water filling the chamber 64 passes through the porous ceramic plate 63, oozes out on the plate 63, and floats the wafer A. The wafer A can be easily separated from the temporary mounting table 6.

In FIG. 5, the back surface of the robot arm 4 has a large number of holes 4a, 4a,... Having a diameter of 0.5 to 1 mm, and the wafer A is sucked by reducing the pressure in the chambers 4b, 4b. The robot arm 4 is provided on the shaft 3 and includes two rotatable arms 4c and an air cylinder 4d.
(See FIG. 3).

In FIG. 1, the storage cassettes 5, 5 '
The robot arm 4 is installed on the same circular ring at a distance of 60 degrees from the three axes. In the grinding apparatus 1 shown in FIG. 1, the axis of the robot arm 4, the axis of the temporary mounting table 6, and the axis of the chuck mechanism 8 of the wafer cleaning apparatus 10 are provided on the same straight line.
This straight line, the brush cleaner 15a and the chuck cleaner 1
5b of the pair of lateral movement trajectories and the rough grinding machine 16
Since the straight line connecting the axis of the rotary shaft 16a of b and the axis of the rotary shaft 16c of the finishing grinder 16d is provided at a position parallel to each other, the design can be made more compact.

In order to grind the wafer A using the grinding apparatus 1, the shaft 3 is moved up and down to move the wafer A in the cassette 5.
The robot arm 4e is extended by operating the air cylinder 4d, and the arm 4e is inserted under the cassette for suction with the suction hole 4a as the upper surface, and the wafer is sucked to the arm 4e. Adsorb. Then, the air cylinder is operated to retract the robot arm 4 while contracting it, and the arm 4e is rotated to position the sucked wafer below the arm 4e.

When the shaft 3 is rotated, the robot arm 4 is extended, and the sucked wafer is transferred onto the temporary mounting table 6, the decompression is stopped, and the wafer is mounted on the porous ceramic plate 63 on the temporary mounting table 6. Guide the cleaning water into the chamber 64,
Cleaning water is spread from the porous ceramics plate 63 to clean the back surface of the wafer. The robot arm 4 is extended from above the washed wafer, and the shaft 3 is lowered to attract the wafer to the arm 4e.

The robot arm 4 is retracted and retracted, and the shaft 3
And the robot arm is again advanced and extended, and the porous ceramic grinding table 12 on the index table 13 washed with water and the brush of the brush washer 15a.
The wafer is placed on the robot arm by stopping the decompression of the robot arm, and then the arm is folded while the robot arm is retracted.

By rotating the shaft 11, the index table 1
3 is rotated to the right by 120 degrees, a wafer is placed, and the suctioned grinding table 12 is positioned below the rough grinding machine 16b. The rotating shaft 16a of the rough grinding machine 16b is lowered,
The provided grindstone is pressed against the wafer, and the wafer is rotated by the rotation of the grinding table 12 and the rough grinding machine 16b.
Next grinding.

The number of rotations of the rotating shaft during the primary grinding is 50
The rotation direction of both shafts may be either forward or reverse, but rotation in the opposite direction is more preferable. Grinding table 1
2. When the primary grinding (rough grinding) is completed after the rotation of the rough grinding machine 16b is stopped, the rough grinding machine 16b is raised, and then the index table 13 is rotated to the right by 120 degrees, and the rough ground wafer is rotated. Is moved below the finish grinding machine 16d.

The finish grinding machine 16d is lowered, the grindstone is pressed against the wafer, and the grinding table 12 and the finish grinding device are rotated to finish grind the wafer (secondary grinding).
Perform The rotation speed is 10 to 200 rpm, and the rotation directions of both shafts may be either forward or reverse, but the reverse direction is preferable.
When finish grinding is finished by stopping the rotation of the finishing table 16d on the grinding table 12, the finish grinding machine 16d
d, and the index table 13 is shifted rightward by 1
The wafer is rotated by 20 degrees and returned to the position where the wafer was first placed on the index table.

Next, the suction pad 17 is rotated about the shaft 17b.
is rotated, the suction pad 17a is brought to the upper surface of the finish-ground wafer, and the shaft 17b is lowered to suck the wafer onto the suction pad, and the shaft 17b is raised and rotated to rotate the wafer cleaning apparatus 10. After the wafer is moved onto the suction chuck mechanism 8 and the pressure reduction of the suction pad is stopped, the finish-ground wafer is placed on the porous ceramic plate of the suction chuck mechanism 8, and the chuck mechanism 8 is depressurized to firmly suck the wafer. By lowering the shaft 7, the position of the porous ceramic plate of the chuck mechanism 8 and the porous ceramic plate 9, which is arranged around the porous ceramic plate,
The height positions of 9, 9,... Are assumed to be approximately the same height.

Then, the wafer which has been subjected to water leaching from the plates 9, 9, 9,... Is immersed in water to wash the wafer, and after washing with water, the shaft 7 is raised to remove the wafer on the chuck mechanism 8. The robot arm 4 is moved to a position higher than the water surface, and the robot arm 4 is rotated, moved forward, extended, and the upper surface of the finished and ground wafer is sucked by the arm 4e, the decompression of the chuck mechanism 8 is stopped, and then dry air is blown from the hollow shaft 7. Soak and dry the backside of the wafer.

The robot arm 4 sucking the dried wafer retreats, folds the arm, pivots, advances and extends the arm 4e again, and stores the finish-ground wafer in the storage cassette 5 '. The arm is folded and rotated, and the arm 4e is further inverted to prepare for transfer of the next new wafer. During the rough grinding and finish grinding of the wafer, the polishing table 12 on which no wafer is mounted moves the brush cleaner 15a of the grinding table cleaner 15 to the right side, and the polishing table 12 made of porous ceramics is washed with water. After cleaning with a brush, the brush cleaner 15a is moved to the left side to return to the original position, the chuck cleaner 15b made of porous ceramics is lowered, pressed against the grinding table 12, and rotated to condition the grinding table 12. The brush cleaner 15a is moved to the right again to perform brush water cleaning and then water cleaning of the grinding table, and then moved to the left again to return to the original position. The conditioning of the table 12 is terminated. The above is the entire wafer grinding process. The robot arm 4 is operated to suck the wafer A to be newly ground into the storage cassette 5, and the grinding of the second wafer is started.

[0028]

According to this grinding apparatus, since the wafer storage cassette and the setting direction are vertically installed, the wafer can be placed without jumping out of the cassette, so that there is no breakage of the wafer due to an operation error. Because of the index method, grinding can be performed without removing the wafer from the grinding table until loading, rough grinding, finish grinding, and unloading of the wafer. The safety door protects workers from danger during operation of the device. Since the arrangement of each device is designed to be companion, the installation area of the grinding machine may be small.

[Brief description of the drawings]

FIG. 1 is a top view of a grinding device of the present invention.

FIG. 2 is a front view of the grinding device of the present invention.

FIG. 3 is a perspective view showing a main part of the grinding device of the present invention.

FIG. 4 is a cross-sectional view of a temporary table.

FIG. 5 is a plan view showing the arm tip on the back surface of the robot arm.

FIG. 6 is a plan view of a known grinding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Grinding device 2 Base 3 Axis 4 Robot arm 5, 5 'Storage cassette 6 Temporary mounting table 8 Chuck mechanism 10 Wafer cleaning device 12 Grinding table 13 Index table 14 Rail 15 Grinding table cleaner 16b Rough grinder 16d Finish grinder 17 Wafer Transfer mechanism 18 Safety door

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahiko Kato 3009 Kamiyori, Atsugi City, Kanagawa Prefecture Okamoto Machine Tool Works, Ltd. Semiconductor Division

Claims (4)

[Claims] 1. A robot arm 4 mounted on a base 2 to be vertically movable and rotatable and rotatable and rotatable in a horizontal direction. Vertical storage cassette 5 for a plurality of wafers provided at an annular position having a center point of the same circle as the axis of
5 ', a temporary mounting table 6 for the wafer that can wash the back surface of the wafer provided on the left side of the shaft 3 with water, and an upper and lower side provided on the right side of the axis 3 opposite to the temporary mounting table 6 for the wafer. A wafer cleaning apparatus 10 having a suction chuck mechanism 8 mounted on a movable shaft 7 and a plate 9 capable of supplying water around the chuck mechanism;
Three rotatable grinding tables 1 supported on a rotatable shaft 11 provided on the rear side of the shaft 3 of the robot arm
Index table 1 in which 2 are provided at equal intervals from axis 11
3. a rail 14 provided separately on the index table 13, a brush cleaner 15a and a chuck cleaner 15b provided opposite to the index table.
, A grinding table cleaning device 15 mounted on the rail 14 so as to be able to travel in the lateral direction, and rough grinding supported by a rotating shaft 16a provided above the index table 13 and on the rear side of the grinding table cleaning device 15. Equipment 16b
And a frame grinding machine 1 having a finish grinding machine 16d mounted on a rotary shaft 16c. 2. A rotatable wafer transfer mechanism 17 having a suction pad 17a capable of transferring a wafer on the temporary table 6 onto the grinding table 12, or a wafer cleaning apparatus 10 2. The wafer grinding apparatus 1 according to claim 1, further comprising a rotatable wafer transfer mechanism 17 'having a suction pad 17a capable of transferring the wafer onto the suction chuck mechanism. 3. The base 2 of the wafer grinding apparatus 1 has a semi-circular front, and a semi-circular rail 2a is provided on the front surface of the vertical storage cassette 5 for a plurality of wafers and the upper surface of the base 2. The safety door 1 is a double door that can be moved on this rail.
3. An apparatus according to claim 1, wherein said first and second control units are provided.
2. The wafer grinding device 1 according to 1. 4. The axis of the robot arm 4, the axis of the temporary mounting table 6, and the axis of the chuck mechanism 8 of the wafer cleaning apparatus 10 are on a straight line, and the straight line is used for the brush cleaning machine 15a and the chuck cleaner 15b. The pair of horizontal movement axis traces, the axis of the rotating shaft 16a of the rough grinding machine 16b, and the finish grinding machine 1
4. The wafer grinding apparatus 1 according to claim 1, wherein a straight line connecting the axis of the 6d rotary shaft 16c is located in parallel with each other.