JP2003059872A - Grinding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding apparatus having a mechanism which can properly select an attracting region, corresponding to the size of a grinding object for carrying out the grinding object. SOLUTION: This grinding apparatus has a chunk table, which can properly attract and hold grinding objects having different diameters, a grinding means which grinds the grinding object attracted and held by the chuck table, and a grinding object carry-out mechanism 40 which can attract, hold, and carry out the grinding object ground on the chuck table. The grinding object carry-out mechanism 40 has an attraction pad 44, having a plurality of attracting regions which have different diameters and are formed concentrically and an attracting means 50, which applies negative pressure to the plurality of attracting regions, and corresponding to the diameter of the grinding object, negative pressure is selectively applied to one of the plurality of attracting regions of the attraction pad 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding apparatus provided with a workpiece unloading mechanism that sucks and holds a workpiece that is placed on a chuck table and ground by a grinding means and carries it out.

[0002]

As is well known to those skilled in the art, in a semiconductor device manufacturing process, the back surface of a semiconductor wafer on which a plurality of circuits such as IC and LSI are formed is ground by a grinding machine to thinly process the semiconductor wafer. There is. The semiconductor wafer is divided into chips for each circuit and is widely used for electric devices such as mobile phones, personal computers and smart cards. To meet the demand for lighter weight and smaller size, the semiconductor wafer is 100 μm or less, preferably Is processed to a thickness of 50 μm or less.

A grinding apparatus for grinding the back surface of a semiconductor wafer includes a chuck table for sucking and holding a work piece, a grinding means for grinding the work piece sucked and held on the chuck table, and grinding on the chuck table. It is equipped with a workpiece unloading mechanism that suctions and holds the processed workpiece and carries it out. However, semiconductor wafers having diameters of 5 inches, 6 inches, and 8 inches are generally used, and in order to handle semiconductor wafers of each size with one grinding machine, each semiconductor wafer of each size is used. A chuck table mechanism that can selectively suck and hold is required. For this reason, recent grinding machines are provided with a chuck table having a plurality of suction regions having different diameters, and the suction regions can be appropriately selected according to the size of the semiconductor wafer.

[0004]

The semiconductor wafer ground on the chuck table is carried out by a carry-out mechanism having a suction pad that holds the surface of the semiconductor wafer by suction. In order to prevent the thin semiconductor wafer sucked and held by the suction pad from being broken when the semiconductor wafer is unloaded, the entire surface of the semiconductor wafer needs to be sucked and held by the suction pad. However, when grinding semiconductor wafers of different sizes, it is necessary to change the suction pad of the carry-out mechanism each time according to the size of the semiconductor wafer to be ground, which is troublesome and the production efficiency is high. It causes a drop. When semiconductor wafers of different sizes are randomly supplied to the chuck table, there is no room to replace the suction pad each time,
If a suction pad corresponding to a small-sized semiconductor wafer is used in order to avoid suction failure, there is a problem that the semiconductor wafer is damaged when the large-sized semiconductor wafer is suction-held.

The present invention has been made in view of the above facts, and its main technical problem is to provide a workpiece unloading mechanism capable of appropriately selecting a suction region in accordance with the size of the workpiece to be ground. To provide a grinding machine.

[0006]

In order to solve the above-mentioned main technical problems, according to the present invention, a chuck table capable of appropriately suction-holding workpieces having different diameters, and a workpiece suction-held on the chuck table. In a grinding apparatus including a grinding means for grinding a workpiece and a workpiece unloading mechanism for sucking and holding the workpiece ground on the chuck table, the workpiece unloading mechanism includes concentric circles. A suction pad having a plurality of suction regions having different diameters and a suction means for exerting a negative pressure on the plurality of suction regions, and the suction pad of the suction pad corresponding to the diameter of the workpiece is provided. A grinding device is provided, which is configured to selectively apply a negative pressure to a plurality of suction regions.

The suction means comprises a plurality of pipes respectively communicating with the plurality of suction regions, a suction source connected to the plurality of pipes, and an on-off valve arranged in each of the plurality of pipes. ing. Further, according to the present invention, there is provided a grinding device provided with a compressed air supply means for appropriately supplying compressed air to the plurality of suction regions. Further, according to the present invention, there is provided a grinding device in which a cleaning means for cleaning the suction pad is arranged on the moving path of the suction pad.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a grinding machine constructed according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view of a grinding apparatus equipped with a workpiece unloading mechanism constructed according to the present invention.
The grinding device in the illustrated embodiment includes a substantially rectangular parallelepiped device housing 2. Figure 1 of device housing 2
A stationary support plate 4 is erected at the upper right end of the.
On the inner side surface of the stationary support plate 4, two pairs of guide rails 6, 6 and 8, 8 extending in the vertical direction are provided. A rough grinding unit 10 as a rough grinding means is movably mounted on one of the guide rails 6 and 6 in the vertical direction, and a finish grinding unit 12 as a finish grinding means is vertically mounted on the other guide rails 8, 8. It is mounted so that it can move in any direction.

The rough grinding unit 10 includes a unit housing 101, a grinding wheel 102 rotatably mounted on the lower end of the unit housing 101, and a grinding wheel 102 mounted on the upper end of the unit housing 101 in a direction indicated by an arrow. Rotation drive mechanism 103 that can be rotated
And the moving base 10 on which the unit housing 101 is mounted
4 and. Guide rails 105, 105 are provided on the moving base 104.
The rough grinding unit 10 is movably supported in the vertical direction by movably fitting the guide rails 05 and 105 to the guide rails 6 and 6 provided on the stationary support plate 4. The rough grinding unit 10 in the illustrated form is the moving base 104.
To move along the guide rails 6, 6
A feed mechanism 11 for adjusting the cutting depth of 2 is provided. The feed mechanism 11 includes a male screw rod 111 that is rotatably supported on the stationary support plate 4 in parallel with the guide rails 6 and 6 in a vertical direction, and a pulse motor 112 that drives the male screw rod 111 to rotate. , The moving base 1
04 has a female screw block (not shown) that is screwed into the male screw rod 111 and is screwed to the male screw rod 111.
The rough grinding unit 10 is moved in the vertical direction by driving the male screw rod 111 in the normal and reverse directions.

The finish grinding unit 12 is also constructed similarly to the rough grinding unit 10, and includes a unit housing 121, a grinding wheel 122 rotatably mounted on the lower end of the unit housing 121, and an upper end of the unit housing 121. Attached to the rotary drive mechanism 123 for rotating the grinding wheel 122 in the direction indicated by the arrow.
And the moving base 12 equipped with the unit housing 121
4 and. Guide rails 125 and 125 are provided on the moving base 124.
The finishing grinding unit 12 is movably supported in the vertical direction by movably fitting the guide rails 8 and 8 provided on the stationary support plate 4 with 25 and 125. The finish grinding unit 12 in the illustrated embodiment includes a feed mechanism 13 that moves the moving base 124 along the guide rails 8 and 8 to adjust the cutting depth of the grinding wheel 122. The feed mechanism 13 has substantially the same configuration as the feed means 11. That is, the feed mechanism 13 includes a male screw rod 131 rotatably supported on the stationary support plate 4 in the vertical direction in parallel with the guide rails 6, 6, and a pulse motor for rotationally driving the male screw rod 131. 132 and a female screw block (not shown) that is mounted on the moving base 124 and screwed with the male screw rod 131. The male screw rod 121 is driven by the pulse motor 132.
The normal grinding and reverse rotation drives the finishing grinding unit 12 in the vertical direction.

The grinding machine in the illustrated embodiment comprises a turntable 15 which is arranged on the front side of the stationary support plate 4 so as to be substantially flush with the upper surface of the machine housing 2. The turntable 15 is formed in a disk shape having a relatively large diameter, and is appropriately rotated in a direction indicated by an arrow 15a by a rotation driving mechanism (not shown). In the illustrated embodiment, the turntable 15 has three chuck tables 20 each having a phase angle of 120 degrees.
Are rotatably arranged in a horizontal plane. As shown in FIG. 2, the chuck table 20 includes a disk-shaped base 21 and a disk-shaped suction holding chuck 22. The base 21 is made of an appropriate metal material, and has a circular recess 213, an annular recess 214, and an annular recess 215 which are partitioned by annular partition walls 211 and 212 formed in a concentric shape and having different diameters and which are open upward. I have it. Therefore, the circular recess 213, the annular recess 214, and the annular recess 215 form the annular partition walls 211 and 212.
Are made independent of each other and are formed in concentric circles. The circular recess 21 formed independently in this way
3 and the annular recess 214 and the annular recess 215 are respectively connected to the communication paths 216, 217 and 21 provided in the base 21.
8 and is connected to a suction source 25 such as a vacuum tank via pipes 241, 242 and 243, respectively. It should be noted that the pipes 241, 242 and 243 respectively have normally-closed electromagnetic open / close valves 261, 262 and 2 respectively.
63 is provided and is controlled to be opened / closed by control means (not shown). When the electromagnetic opening / closing valve 261 is energized, the circular recess 213 communicates with the suction source 25, and the electromagnetic opening / closing valve 262 is opened.
Is pressed, the annular recess 214 communicates with the suction source 25,
When the electromagnetic opening / closing valve 263 is energized, the annular recess 215 is brought into communication with the suction source 25. Therefore, the pipe 241,
242, 243, electromagnetic on-off valves 261, 262, 263,
The suction source 25 functions as a suction unit that applies a negative pressure to the plurality of suction regions.

A suction holding chuck 22 constituting the chuck table 20 has a circular recess 2 formed in a base 21.
13 and the annular concave portion 214 and the annular concave portion 215, which are respectively fitted into the disk-shaped porous ceramic member 221 and the annular porous ceramic members 222 and 223, and have a disk shape as a whole. The chuck table 20 including the above-described base 21 having the circular recess 213, the annular recesses 214 and 215, the disk-shaped porous ceramic member 221, and the annular porous ceramic members 222 and 223 is concentrically formed and has a diameter. Has a plurality of (three in the illustrated embodiment) suction regions. The suction area formed by the circular recess 213 and the disk-shaped porous ceramic member 221 is set to have a size corresponding to a semiconductor wafer having a diameter of 5 inches. The suction region formed by the circular recess 213 and the annular recess 214, the disk-shaped porous ceramic member 221, and the annular porous ceramic member 222 is set to a size corresponding to a semiconductor wafer having a diameter of 6 inches. Has been done. Further, the suction region constituted by the circular recess 213, the annular recesses 214 and 215, the disk-shaped porous ceramic member 221, and the annular porous ceramic members 222 and 223 corresponds to a semiconductor wafer having a diameter of 8 inches. It is set to the size. The chuck table 20 configured as described above is rotated in the direction indicated by an arrow 15a by a rotation drive mechanism (not shown) as shown in FIG. The three chuck tables 20 arranged on the turntable 15 include a workpiece loading / unloading area A, a rough grinding processing area B, a finish grinding processing area C, and a workpiece by appropriately rotating the turntable 15. Loading / unloading area A
Can be moved to.

The grinding apparatus shown in the drawing is a first cassette 31 which is arranged on one side of the work-piece carrying-in / carrying-out area A and stocks a semiconductor wafer which is a work piece before grinding.
And a second cassette 32 for stocking a semiconductor wafer which is a workpiece after grinding, which is arranged on the other side of the workpiece loading / unloading area A, the first cassette 31, and the workpiece loading. -Workpiece loading portion 33 provided between the carry-out area A, the work-piece carry-in / carry-out area A and the second cassette 32
Cleaning means 34 disposed between the first cassette 3 and the cleaning means 34.
A semiconductor wafer, which is a workpiece housed in the workpiece 1, is carried out to the workpiece mounting portion 33, and a semiconductor wafer cleaned by the cleaning means 34 is transferred to the second cassette 32; , A work piece carry-in means 36 for carrying the semiconductor wafer placed on the work piece placing part 33 onto the chuck table 20 positioned in the work piece carry-in / carry-out area A, and a work piece carry-in / carry-out A work piece carry-out means 40 for carrying the ground semiconductor wafer placed on the chuck table 20 positioned in the area A to the cleaning means 34, and a suction pad of the work piece carry-out means 40 to be described later. The suction pad cleaning means 60 arranged on the moving path is provided.

Next, the workpiece carrying-out means 40 is shown in FIG.
Will be described with reference to FIGS. 2 and 3. The workpiece unloading means 40 in the illustrated embodiment includes an L-shaped actuating arm 41. The L-shaped actuating arm 41 includes a vertical portion 411 and a horizontal portion 412.
The lower end of 1 is connected to the lifting mechanism 42. Lifting mechanism 4
Reference numeral 2 is, for example, an air piston or the like, and operates the actuating arm 41 in the vertical direction as indicated by an arrow 40a in FIG. Further, the elevating means 42 connected to the vertical portion 411 of the operation arm 41 is connected to the operation mechanism 43 including an electric motor capable of forward / reverse rotation. Therefore, by driving the actuating mechanism 43 in the forward or reverse direction, the actuating arm 41 is swung in the direction indicated by the arrow 40b in FIG. 1 about the vertical portion 411. As a result, the horizontal portion 412 of the operating arm 41 is operated in the horizontal plane, and the suction pad 44, which will be described later, attached to the tip of the horizontal portion 412 is operated in the horizontal plane.
The elevating mechanism 42 and the operating mechanism 43 are controlled by a control means (not shown).

The suction pad 44 mounted on the tip of the horizontal portion 412 of the operating arm 41 comprises a disc-shaped base 45 and a pad 46 as shown in FIGS. The base 45 is made of an appropriate metal material, and a support shaft portion 45a is formed so as to project at the center of the upper surface of the base 45. The support shaft portion 45a is attached to the tip of the horizontal portion 412 forming the operation arm 41. To be done. A locking portion 45b is provided on the upper end of the support shaft portion 45a.
b is engaged with an engaging portion 413 formed on the horizontal portion 412. A compression coil spring 47 is arranged between the upper surface of the base 45 and the horizontal portion 412 forming the operation arm 41, and biases the base 45 downward.

The base 45 constituting the suction pad 44 has an outer diameter substantially the same as that of the base 21 constituting the chuck table 20, and is formed as a concentric circular partition wall 451 having a different diameter. And a circular recess 453, which is divided by 452 and whose lower side is open, an annular recess 454, and an annular recess 455. Therefore, the circular concave portion 453, the annular concave portion 454, and the annular concave portion 455 are formed as concentric circles by being made independent by the annular partition walls 451 and 452, respectively. The diameters of the annular partition walls 451 and 452 are the same as those of the annular partition walls 211 and 212 provided on the base 21 that constitutes the chuck table 20. The circular recess 453 formed on the base 45 in this way is
It is connected to a pipe 481 such as a flexible pipe arranged in the operation arm 41 via a communication passage 456 provided in the support shaft portion 45a. The annular recess 454 and the annular recess 455 formed on the base 45 are connected to pipes 482 and 483 such as flexible pipes through communication passages 457 and 458, respectively.

The pipes 481, 482 and 483 are arranged through the vertical portion 411 of the operating arm 41, and are connected to the suction source 50 such as a vacuum tank via the pipes 491, 492 and 493, respectively. The pipes 491, 4
92 and 493 are normally closed solenoid on-off valves 50, respectively.
1, 502, and 503 are provided, and opening / closing is controlled by control means (not shown). When the electromagnetic opening / closing valve 501 is energized, the pipe 491, the pipe 481 and the communication passage 456 are provided.
The circular recess 453 communicates with the suction source 50 via the pipe, and when the electromagnetic opening / closing valve 502 is energized, the pipe 492 and the pipe 482 are connected.
The annular recess 454 is connected to the suction source 5 via the communication passage 457.
0 and the solenoid valve 503 is energized, the piping 49
3, the annular recess 4 via the pipe 483 and the communication passage 458.
55 is brought into communication with the suction source 50. Therefore, the pipes 481, 482, 483 and the pipes 491, 492, 49
3, electromagnetic on-off valves 501, 502, 503, suction source 50
Functions as a suction unit that applies a negative pressure to the plurality of suction regions of the suction pad.

Pipes 511, 512, 513 are connected to the pipes 491, 492, 493, respectively, and the pipes 511, 512, 513 are connected to a compressed air source 52 such as an air tank. In addition, the pipes 511, 51
2 and 513 each have a normally closed solenoid valve 52
1, 522 and 523 are provided and are controlled to be opened / closed by control means (not shown). When the electromagnetic on-off valve 521 is energized, the circular recess 453 communicates with the compressed air source 52 via the pipe 511, the pipe 491, the pipe 481 and the communication passage 456, and when the electromagnetic on-off valve 522 is energized, the pipe 5
12, the annular recess 454 communicates with the compressed air source 52 through the pipe 492, the pipe 482, and the communication passage 457, and when the electromagnetic opening / closing valve 523 is energized, the pipe 513, the pipe 493, the pipe 483, and the communication passage 458. The annular recess 455 is brought into communication with the compressed air source 52. Therefore, the pipes 481, 482, 483 and the pipes 491, 492, 49
3, solenoid on-off valves 521, 522, 523, compressed air source 5
Reference numeral 2 functions as a compressed air supply unit that appropriately supplies compressed air to the plurality of suction regions of the suction pad.

The pad 46 constituting the suction pad 44 is
Circular recess 453 and annular recess 4 formed on the base 45
54 and a ring-shaped concave portion 455, each of which is made up of a disk-shaped porous ceramic member 461 and ring-shaped porous ceramic members 462 and 463, and has a disk shape as a whole. As described above, the suction pad 44 including the pad 46 including the disk-shaped porous ceramic member 461 and the annular porous ceramic members 462 and 463 and the base 45 including the circular recess 453 and the annular recesses 454 and 456 is As shown in FIGS. 2 and 3, there are a plurality of (three in the illustrated embodiment) suction regions that are concentrically formed and have different diameters. The suction area formed by the circular recess 453 and the disk-shaped porous ceramic member 461 is the suction area formed by the circular recess 213 of the chuck table 20 and the disk-shaped porous ceramic member 221. It is configured to the corresponding size. The suction area formed by the annular recess 454 and the annular porous ceramic member 462 and the suction area formed by the annular recess 455 and the annular porous ceramic member 463 are:
The chuck table 20 has a size corresponding to the suction area formed by the annular recess 214 and the annular porous ceramic member 222 and the suction area formed by the annular recess 215 and the annular porous ceramic member 223, respectively. There is.

Next, the suction pad cleaning means 60 arranged on the moving path of the suction pad 44 in the workpiece unloading means 40 will be described with reference to FIG. The suction pad cleaning means 60 in the illustrated embodiment includes a cleaning housing 61, a cylindrical cleaning brush 62 in which brushes are planted on the outer periphery of a rotation shaft rotatably disposed in the cleaning housing, and the cleaning. A brush cleaning brush 63 having a cylindrical shape, which is disposed below the brush 61 and has brushes implanted on the outer circumference of the rotating shaft, and a rectangular flat plate-shaped grinding wheel 64 disposed in parallel with the cleaning brush 62 are provided. There is. The cleaning brush 62 and the brush cleaning brush 63 are rotated in the same direction by a rotation driving means (not shown). In addition, the grinding wheel 64 uses the swing drive means (not shown) to clean the cleaning brush 6
1 can be reciprocated in the axial direction. The suction pad cleaning means 60 in the illustrated embodiment
Are three cleaning liquid jet nozzles 651, 652, 65 for supplying the cleaning liquid to the cleaning brush 62 and the grinding wheel 64.
3 is provided with a cleaning liquid supply means 65. The suction pad cleaning means 60 configured as described above is arranged on the movement path of the suction pad 44 between the workpiece loading / unloading area A in the apparatus housing 2 and the cleaning means 34 as shown in FIG. .

The grinding apparatus in the illustrated embodiment is configured as described above, and its operation will be described below. First, the processing operation of the above-described grinding device will be briefly described. The semiconductor wafer, which is the workpiece to be ground and is not yet ground, accommodated in the first cassette 31 is transported by the vertical movement and the forward / backward movement of the workpiece transfer means 35, and is placed on the workpiece mounting portion 33 to place six pieces. Centered by radial movement towards the center of the pin 331. The semiconductor wafer placed on the workpiece placing portion 33 and centered is
By the turning operation of the workpiece carry-in means 36, the workpiece is placed on the chuck table 20 positioned in the workpiece carry-in / carry-out area A. Referring to FIG. 2, at this time, when the size of the semiconductor wafer is 5 inches, the size of the semiconductor wafer is set on the disk-shaped porous ceramic member 221 of the suction holding chuck 22 constituting the chuck table 20. 6 inches, the disk-shaped porous ceramic member 221 and the annular porous ceramic member 2
22. When the size of the semiconductor wafer is 8 inches, it is placed on the disk-shaped porous ceramic member 221 and the annular porous ceramic members 222 and 223. When the semiconductor wafer is placed on the chuck table 20, the electromagnetic opening / closing valve 261 is corresponding to the size of the semiconductor wafer placed on the chuck table 20,
262 and 263 are energized (ON). That is, when the size of the semiconductor wafer is 5 inches, the electromagnetic on-off valve 261 is energized (ON), and when the size of the semiconductor wafer is 6 inches, the electromagnetic on-off valves 261 and 262 are energized (ON). Solenoid valve 26 when the size is 8 inches
1 and 262 and 263 are energized (ON). As a result, the recesses 213 and 21 in the regions corresponding to the sizes of the semiconductor wafers placed on the chuck table 20 are formed.
4, 215 are connected to the suction source 25 so that the semiconductor wafer can be suction-held on the suction-holding chuck 22. Then, the turntable 15 is rotated by 120 degrees in a direction indicated by an arrow 15a by a rotation drive mechanism (not shown), and the chuck table 2 on which the semiconductor wafer is mounted.
Position 0 in the rough grinding area B.

When the chuck table 20 on which the semiconductor wafer is placed is positioned in the rough grinding area B, it is rotated in the direction shown by the arrow by a rotation drive mechanism (not shown), while the grinding wheel 102 of the rough grinding unit 10 is shown by the arrow. The chuck table 20 is lowered by a predetermined amount by the feeding mechanism 11 while being rotated in the direction shown.
Rough grinding is applied to the upper semiconductor wafer. The semiconductor wafer before grinding is placed on the next chuck table 20 positioned in the workpiece carry-in / carry-out area A during this period, as described above. Then, as described above, the electromagnetic on-off valves 261, 262, 263 corresponding to the size of the semiconductor wafer placed on the chuck table 20 are used.
Is turned on to hold the semiconductor wafer on the suction holding chuck 22 by suction. Next, the turntable 15 is rotated 120 degrees in the direction indicated by the arrow 15a, and the chuck table 2 on which the semiconductor wafer subjected to the rough grinding is placed.
Position 0 in the finishing grinding area C. At this time, in the workpiece loading / unloading area A, the next chuck table 20 on which the semiconductor wafer is placed is positioned in the rough grinding processing area B, and the next chuck table 20 is the workpiece loading / unloading area. When positioned at A, the electromagnetic opening / closing valves 261, 262, 263 are energized as described above in accordance with the size of the semiconductor wafer placed on the chuck table 20 (O.
Then, the semiconductor wafer is suction-held on the suction-holding chuck 22.

In this way, the semiconductor wafer placed on the chuck table 20 positioned in the rough grinding area B before rough grinding is subjected to rough grinding by the rough grinding unit 10 and finish grinding. The finish grinding unit 12 performs the finish grinding process on the semiconductor wafer which is placed on the chuck table 20 positioned in the area C and subjected to the rough grinding process. Next, turntable 15
Is rotated 120 degrees in the direction indicated by the arrow 15a, and the chuck table 20 on which the semiconductor wafer subjected to finish grinding is placed is positioned in the workpiece loading / unloading area A. The chuck table 20 on which the semiconductor wafer rough-ground was placed in the rough-grinding area B was placed in the finish-grinding area C and the semiconductor wafer before grinding was placed in the workpiece loading / unloading area A. The chuck table 20 is moved to the rough grinding area B, respectively.

The chuck table 20, which has returned to the workpiece loading / unloading area A via the rough grinding processing area B and the finish grinding processing area C, releases the suction holding of the semiconductor wafer subjected to the finish grinding processing. To do. That is, the electromagnetic opening / closing valves 261, 262, 263 that have been energized (ON) corresponding to the size of the semiconductor wafer when adsorbed and held on the chuck table 20 as described above are deenergized (OFF), and the chuck table 20 is removed. The communication between the concave portions 213, 214, 215 and the suction source 25 in the region corresponding to the size of the semiconductor wafer sucked and held by the suction source 25 is blocked. Then, the semiconductor wafer subjected to the finish grinding on the chuck table 20 positioned in the workpiece carry-in / out zone A is carried to the cleaning means 34 by the workpiece carry-out means 40. That is, to explain with reference to FIG. 2, the upper surface of the workpiece placed on the chuck table 20 in which the suction pad 44 is returned to the workpiece loading / unloading area A by operating the elevating mechanism 42 and the operating mechanism 43. Position. Next, the electromagnetic opening / closing valves 501, 502, and 503 are energized (ON) corresponding to the size of the semiconductor wafer on the chuck table 20 that has been subjected to finish grinding. That is, when the size of the semiconductor wafer is 5 inches, the solenoid opening / closing valve 501 is energized (ON), and when the size of the semiconductor wafer is 6 inches, the solenoid opening / closing valve 50 is turned on.
When 1 and 502 are energized (ON) and the size of the semiconductor wafer is 8 inches, the solenoid opening / closing valves 501, 502 and 5
03 is turned on (ON). As a result, the recesses 453, 454, 455 in the region corresponding to the size of the semiconductor wafer placed on the chuck table 20 are made to communicate with the suction source 50, and the semiconductor wafer can be suction-held on the suction pad 44. In this way, the suction pad 44
If the semiconductor wafer is held by suction on the
And the operation mechanism 43 is operated to convey the semiconductor wafer to the cleaning means 34.

The workpiece carry-out means 40 for carrying out the semiconductor wafer subjected to the finish grinding as described above is constructed so that the suction area of the suction pad 44 can be appropriately selected according to the size of the semiconductor wafer. Since it is not necessary to replace the suction pad each time according to the size of the semiconductor wafer, the productivity can be remarkably improved. Further, the workpiece unloading means 40 can easily select the suction region of the suction pad 44 according to the size of the semiconductor wafer even when semiconductor wafers of different sizes are randomly supplied to the chuck table. Therefore, the suction pad 44 of the workpiece carrying-out means 40 always sucks and holds the entire surface of the semiconductor wafer, so that the thinly ground semiconductor wafer can be safely transported from the chuck table without damage.

Continuing with the description with reference to FIG. 1, if the semiconductor wafer that has been subjected to finish grinding is conveyed to the spinner table of the cleaning means 34 by the workpiece unloading means 40, the semiconductor wafer is suction-held by the suction pad 44. To cancel. That is, as described above, the electromagnetic opening / closing valves 501, 502, and 503 that have been energized (ON) corresponding to the size of the semiconductor wafer during adsorption and holding by the adsorption pad 44 are deenergized (OFF), and the adsorption pad 44 is adsorbed and retained. The recess 45 in the region corresponding to the size of the semiconductor wafer being formed.
The communication between 3, 454, 455 and the suction source 50 is cut off.
The electromagnetic on-off valves 521, 522, 52 constituting the compressed air supply means regardless of the size of the semiconductor wafer.
3 is energized (ON), the circular concave portion 4 of the suction pad 44
53 and the annular recesses 454 and 455 communicate with the compressed air source 52. Therefore, compressed air is introduced into the circular concave portion 453 and the circular concave portions 454 and 455 of the suction pad 44, and the disk-shaped porous ceramic member 461 and the circular porous ceramic member 462 that form the disk-shaped pad 46 of the suction pad 44 Compressed air is ejected from 463. As a result, the semiconductor wafer can be reliably released from the suction pad 44, and the disk-shaped porous ceramic member 221 and the annular porous ceramic members 462 and 463, which are a plurality of suction regions contaminated by grinding dust, are washed. As a result, clogging is prevented. As described above, the semiconductor wafer transferred onto the spinner table of the cleaning means 34 is cleaned here, and then the workpiece transfer means 35 is used to transfer the second cassette 3 to the second cassette 3.
It is stored in two predetermined positions. In the illustrated embodiment, the semiconductor wafer placed on the workpiece placing portion 33 is placed on the chuck table 20 positioned in the workpiece loading / unloading area A by the workpiece loading means 36. However, the workpiece carry-in means 40 may be configured to carry in the workpiece.

As described above, the workpiece carry-out means 40 in the illustrated embodiment conveys the semiconductor wafer that has undergone the finish grinding process to the cleaning means 34 when the suction pad 4 is used.
Disc-shaped pad 46 and disc-shaped porous ceramic member 461 and annular porous ceramic member 46.
2 and 463 are actuated by compressed air to clean a plurality of suction areas contaminated by grinding debris, but if grinding debris or the like is strongly adhered to or bites into the adsorption surface, this is completely removed. It is difficult to remove by washing. Therefore, the workpiece unloading means 40 in the illustrated embodiment is
The suction pad 44 is moved onto the suction pad cleaning means 60 arranged on the moving path, and the suction pad cleaning means 60 is moved.
Thus, the grinding dust and the like that are strongly adhered to or bite into the suction surface of the suction pad 44 are removed by washing. That is, as shown in FIG. 4, the cleaning liquid injection nozzle 65 of the cleaning liquid supply means 65.
While spraying the cleaning liquid from 1, 652, 653, the cleaning brush 62 and the brush cleaning brush 63 are, for example, 200 rp.
While rotating at m, the grinding wheel 64 is, for example, 20
The suction surface of the suction pad 44 is reciprocated in 0 cycle to be cleaned by the rotating cleaning brush 62, and the grinding dust strongly adhered to or absorbed into the suction surface is ground by the reciprocating grinding wheel 64. To wash. Therefore, by suction-holding the small-sized semiconductor wafer, the outer suction area contaminated with grinding dust can be sufficiently washed, and the semiconductor wafer is not damaged when the large-sized semiconductor wafer is suction-held.

[0029]

Since the grinding apparatus according to the present invention is constructed as described above, it has the following effects.

That is, according to the present invention, the work piece unloading mechanism is formed in a concentric shape and has a plurality of suction areas having different diameters, and suction means for applying a negative pressure to the plurality of suction areas. Since it is configured to selectively apply a negative pressure to a plurality of suction regions of the suction pad according to the diameter of the work piece, the suction pad can be changed according to the diameter of the work piece. Since it is not necessary to replace each time, productivity can be significantly improved. Further, the workpiece unloading means can easily select the suction region of the suction pad in accordance with the size of the workpiece even when workpieces of different sizes are randomly supplied to the chuck table. Therefore, since the suction pad of the workpiece unloading means always sucks and holds the entire surface of the workpiece, the thinly ground workpiece can be safely transported from the chuck table without damage.

[Brief description of drawings]

FIG. 1 is a perspective view of a grinding device equipped with a chuck table cleaning device configured according to the present invention.

FIG. 2 is a schematic configuration diagram in which a chuck table and a workpiece unloading mechanism provided in the grinding apparatus shown in FIG.

FIG. 3 is a bottom view of a suction chuck that constitutes a workpiece unloading mechanism equipped in the grinding apparatus shown in FIG.

FIG. 4 is a perspective view of suction pad cleaning means provided in the grinding device shown in FIG.

[Explanation of symbols]

2: Device housing 4: stationary support plate 4 6: Guide rail 8: Guide rail 10: Rough grinding unit 101: Unit housing 102: grinding wheel 103: rotary drive mechanism 104: Moving base 105: Guided rail 11: Feeding mechanism 111: Male screw rod 112: Pulse motor 12: Finishing grinding unit 121: Unit housing 122: Grinding wheel 123: rotary drive mechanism 124: Moving base 125: Guided rail 13: Feeding mechanism 131: Male thread rod 132: Pulse motor 15: Turntable 20: Chuck table 21: Base of chuck table 22: Adsorption holding chuck of chuck table 25: suction source 261262,263: Solenoid on-off valve 31: First cassette 32: Second cassette 33: Workpiece mounting part 34: Cleaning means 35: Workpiece conveying means 36: Workpiece carry-in means 40: Workpiece unloading means 41: Actuating arm 42: Lifting mechanism 43: Operating mechanism 44: suction pad 45: Base of suction pad 46: Pad of suction pad 47: compression coil spring 48: Flexible pipe 50: suction source 501, 502, 503: solenoid valve 52: compressed air source 521, 522, 523: solenoid valve

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B65G 49/07 B65G 49/07 GH01L 21/68 H01L 21/68 BP F term (reference) 3C007 AS12 DS02 FS01 FT10 FT12 FU00 GU03 NS13 3C058 AA04 AB03 CA01 CB02 CB03 DA17 5F031 CA02 FA01 FA07 FA12 GA24 GA42 GA47 GA54 HA02 HA14 HA57 HA60 MA22 PA16 PA24

Claims (4)

[Claims] 1. A chuck table capable of appropriately sucking and holding workpieces having different diameters, a grinding means for grinding the workpieces sucked and held on the chuck table, and a workpiece ground on the chuck table. In a grinding apparatus including a workpiece unloading mechanism that sucks and holds an object and unloads the workpiece, the workpiece unloading mechanism includes a suction pad having a plurality of concentric suction regions having different diameters, A suction means for applying a negative pressure to the plurality of suction areas, and is configured to selectively apply a negative pressure to the plurality of suction areas of the suction pad in accordance with the diameter of the workpiece. A grinding machine characterized by the following. 2. The suction means includes a plurality of pipes respectively communicating with the plurality of suction regions, a suction source connected to the plurality of pipes, and an on-off valve arranged in each of the plurality of pipes. The grinding apparatus according to claim 1, which is provided. 3. The grinding apparatus according to claim 1, further comprising a compressed air supply unit that appropriately supplies compressed air to the plurality of suction regions. 4. The grinding apparatus according to claim 1, wherein a cleaning means for cleaning the suction pad is arranged on a moving path of the suction pad.