JP6985170B2 - Wafer processing method - Google Patents

Description

In the present invention, a plurality of devices are partitioned by a planned division line in the first direction and a planned division line in the second direction intersecting the first direction, and a wafer formed on the surface is divided into individual devices. Regarding the processing method of wafers.

A wafer formed on the surface of a plurality of devices such as ICs and LSIs is divided by a scheduled division line and is divided into individual devices by a dicing device, and each divided device is used for an electric device such as a mobile phone or a personal computer. ..

The dicing device has a chuck table having a holding surface for holding the waha, a cutting means having a detachably equipped cutting blade for cutting the waha held on the chuck table, and a chuck table and a cutting means relative to each other on the X-axis. The wafer is configured to include at least an X-axis feeding means for machining and feeding in the direction and a Y-axis feeding means for indexing and feeding the chuck table and the cutting means relatively in the Y-axis direction orthogonal to the X-axis direction. It can be cut with high precision (see, for example, Patent Document 1).

JP-A-2002-66865

However, when the chuck table is machined and fed relatively in the X-axis direction, the chuck table swings up and down by about 10 μm due to the accuracy of the lead screw or the accuracy of the guide rail, so the depth of the cutting groove is increased. There is a problem that it cannot be maintained with high accuracy.

An object of the present invention made in view of the above facts is to provide a method for processing a wafer, which can maintain the depth of a cutting groove with high accuracy.

In order to solve the above problems, the present invention provides the following wafer processing method. That is, a waha in which a plurality of devices are partitioned by a planned division line in the first direction and a planned division line in the second direction intersecting the first direction, and a waha formed on the surface is divided into individual devices. As a processing method, a chuck table having a holding surface for holding a wafer, a cutting means having a detachably provided cutting blade for cutting the wafer held on the chuck table, and the chuck table and the cutting means are provided. It is provided with at least an X-axis feeding means for machining and feeding relatively in the X-axis direction and a Y-axis feeding means for indexing and feeding the chuck table and the cutting means relatively in the Y-axis direction orthogonal to the X-axis direction. A machining equipment preparation step for preparing a cutting device, a grinding grind mounting step for mounting a grinding grind slightly wider than the distance between a scheduled split line and an adjacent scheduled split line on the cutting means, and an X-axis feed means. The holding surface grinding step of grinding the holding surface of the chuck table with the grinding grind and operating the Y-axis feeding means to index and feed at intervals of the scheduled division lines, and the holding surface grinding step. The cutting blade mounting process of removing the grinding wheel from the cutting means and mounting the cutting blade, and the planned division line in the first direction formed on the wafer are positioned parallel to the X-axis direction and held on the holding surface of the chuck table. The first holding step and the first cutting step of cutting the planned division line in the first direction in the X-axis direction and indexing and feeding in the Y-axis direction to cut the planned division line in the first direction. A second holding step of separating the waha from the chuck table and holding the scheduled division line in the second direction formed on the waha parallel to the X-axis direction on the holding surface of the chuck table. A waiha consisting of at least a second cutting process in which a planned division line in the second direction is cut in the X-axis direction and is indexed and sent in the Y-axis direction to cut the planned division line in the second direction. It is a processing method.

The method for processing a waha provided by the present invention includes a chuck table having a holding surface for holding the waha, a cutting means for detachably providing a cutting blade for cutting the waha held on the chuck table, and the chuck table. An X-axis feed means that processes and feeds the cutting means relatively in the X-axis direction, and a Y-axis feed means that indexes and feeds the chuck table and the cutting means relatively in the Y-axis direction orthogonal to the X-axis direction. A processing device preparation process for preparing a processing device equipped with at least, and a grinding tool mounting process for mounting a grinding wheel slightly wider than the distance between the scheduled split line and the adjacent scheduled split line on the cutting means. The holding surface for grinding the holding surface by operating the X-axis feeding means to grind the holding surface of the chuck table with the grinding grind and operating the Y-axis feeding means to index and feed at intervals of scheduled division lines. The chuck table is positioned parallel to the X-axis direction with the grinding step, the cutting blade mounting step of removing the grinding wheel from the cutting means and mounting the cutting blade, and the planned division line in the first direction formed on the wafer. The first holding step of holding on the holding surface and the planned division line in the first direction are cut in the X-axis direction and indexed and sent in the Y-axis direction to cut the planned division line in the first direction. The first cutting step and the second, in which the waha is separated from the chuck table and the planned division line in the second direction formed on the waha is positioned parallel to the X-axis direction and held on the holding surface of the chuck table. At least from the holding step and the second cutting step of cutting the scheduled split line in the second direction in the X-axis direction and indexing and feeding in the Y-axis direction to cut the scheduled split line in the second direction. Since it is configured, even if the chuck table swings up and down when the chuck table is machined and fed in the X-axis direction, the swing of the chuck table becomes virtually zero at the machining position where the cutting blade cuts, and the cutting groove. Depth can be maintained with high accuracy.

Perspective view of the wafer. The perspective view of the processing equipment prepared in the processing equipment preparation process. FIG. 2 is a perspective view of the cutting means shown in FIG. An exploded perspective view of the cutting means shown in FIG. 2. The perspective view which shows the state which the grinding wheel mounting process is carried out. A perspective view of a cutting means equipped with a grinding wheel instead of a cutting blade. The perspective view which shows the state which the holding surface grinding process is carried out. The perspective view which shows the state which the 1st holding process and the 1st cutting process are carried out. The perspective view which shows the state which the 2nd holding process and the 2nd cutting process are carried out.

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

FIG. 1 shows a wafer 2 that can be processed by the wafer processing method of the present invention. The surface 2a of the disk-shaped wafer 2 has a grid pattern composed of a plurality of scheduled division lines 4a extending in the first direction and a plurality of scheduled division lines 4b extending in the second direction intersecting the first direction. It is divided into a plurality of rectangular areas by a planned division line 4, and a plurality of devices 6 such as ICs and LSIs are formed in each of the plurality of rectangular areas. Further, the distance between the scheduled division line 4 and the adjacent scheduled division line 4 is indicated by reference numeral s in FIG. The wafer 2 in the illustrated embodiment is attached to an adhesive tape 10 whose peripheral edge is fixed to the annular frame 8.

In the method for processing a waha of the present invention, first, a chuck table having a holding surface for holding the waha 2, a cutting means for detachably providing a cutting blade for cutting the waha 2 held on the chuck table, and a chuck table are used. An X-axis feed means for machining and feeding the cutting means relatively in the X-axis direction, and a Y-axis feed means for indexing and feeding the chuck table and the cutting means relatively in the Y-axis direction orthogonal to the X-axis direction. At least the processing equipment preparation process for preparing the equipped processing equipment is carried out. In the processing device preparation step, for example, the processing device 12 shown in FIG. 2 can be prepared. The processing apparatus 12 includes an apparatus housing 14, a chuck table 16 mounted on the apparatus housing 14 so as to be movable in the X-axis direction indicated by an arrow X in FIG. 2, and an X-axis feed that processes and feeds the chuck table 16 in the X-axis direction. It is provided with means (not shown). A porous circular suction chuck 18 is arranged at the upper end portion of the chuck table 16. As shown in FIG. 7, the suction chuck 18 is connected to the suction source 17b by the first flow path 17a and is connected to the water source 19b by the second flow path 19a. A first valve 17c that opens and closes the first flow path 17a is installed in the first flow path 17a. Further, in the second flow path 19a, a second valve 19c that opens and closes the second flow path 19a is installed. Then, in the chuck table 16, after opening the first valve 17c and closing the second valve 19c, the suction source 17b is operated to generate a suction force on the upper surface of the suction chuck 18, so that the chuck table 16 is mounted on the upper surface. The wafer 2 is sucked and held. As described above, in the illustrated embodiment, the holding surface for holding the wafer 2 is formed by the upper surface of the suction chuck 18. Further, in the chuck table 16, water is injected from the upper surface of the suction chuck 18 by closing the first valve 17c and opening the second valve 19c and then operating the water source 19b. Further, on the peripheral edge of the chuck table 16, a plurality of clamps 20 for fixing the annular frame 8 are arranged at intervals in the circumferential direction. As shown in FIG. 2, above the moving path of the chuck table 16, an imaging means 22 for imaging a wafer 2 held by the chuck table 16 and detecting a region to be cut is provided. The X-axis feeding means may be composed of, for example, a ball screw (not shown) connected to the chuck table 16 and extending in the X-axis direction, and a motor (not shown) for rotating the ball screw. .. When the chuck table 16 is machined and fed in the X-axis direction by this X-axis feed means, the chuck table 16 is about 10 μm in the Z-axis direction indicated by the arrow Z in FIG. 2 due to the accuracy of the members constituting the X-axis feed means. It will swing. The Y-axis direction indicated by the arrow Y in FIG. 2 is a direction orthogonal to the X-axis direction, and the plane defined by the X-axis direction and the Y-axis direction is substantially horizontal. Further, the Z-axis direction is a vertical direction orthogonal to the X-axis direction and the Y-axis direction.

The device housing 14 of the processing device 12 has a cutting means 24 supported so as to be movable in the Y-axis direction and movable in the Z-axis direction (elevation / elevation), and a Y-axis feed for indexing and feeding the cutting means 24 in the Y-axis direction. Means (not shown) and Z-axis feeding means (not shown) that cut and feed the cutting means 24 in the Z-axis direction are provided. The Y-axis feed means may be composed of a ball screw connected to the cutting means 24 and extending in the Y-axis direction, and a motor for rotating the ball screw. Further, the Z-axis feed means may be composed of a ball screw connected to the cutting means 24 and extending in the Z-axis direction, and a motor for rotating the ball screw.

The cutting means 24 will be described with reference to FIGS. 3 to 5. The cutting means 24 includes a spindle housing 26 extending in the Y-axis direction, a blade cover 28 attached to the tip of the spindle housing 26, and a spindle 30 rotatably supported by the spindle housing 26 about the Y-axis direction. A motor for rotating the spindle 30 (not shown), an annular cutting blade 32 detachably fixed to the tip of the spindle 30, and a nut 34 for fixing the cutting blade 32 to the tip of the spindle 30. include. As shown in FIGS. 3 and 4, the blade cover 28 has a first cover member 36 arranged at the tip of the spindle housing 26 and a second cover fixed to the front surface of the first cover member 36 by screws 38. It has a member 40 and a blade detection block 44 fixed to the upper surface of the first cover member 36 by a screw 42. The first cover member 36 includes a first cutting water supply nozzle 36a (see FIG. 4) extending along the side surface of the cutting blade 32 and a first inlet pipe communicating with the first cutting water supply nozzle 36a. 36b is provided. Further, the second cover member 40 includes a second cutting water supply nozzle 40a extending along the side surface of the cutting blade 32 when the second cover member 40 is fixed to the first cover member 36. A second inlet pipe 40b communicating with the second cutting water supply nozzle 40a is provided. Both the first inlet pipe 36b and the second inlet pipe 40b are connected to a cutting water supply source (not shown). Then, in the cutting means 24, when the waha 2 is cut by the cutting blade 32, the cutting water is injected from the first cutting water supply nozzle 36a and the second cutting water supply nozzle 40a toward the cutting blade 32 and the waha 2. It is designed to do. The blade detection block 44 is provided with a blade sensor (not shown) for detecting wear or chipping of the cutting blade 32, and an adjusting screw 44a for adjusting the Z-axis direction position of the blade sensor. The blade sensor may be composed of a light emitting element and a light receiving element. As shown in FIG. 5, an annular flange 30a is provided on the outer peripheral surface on the distal end side of the spindle 30, and a male screw 30b is formed on the outer peripheral surface of the spindle 30 further on the distal end side than the flange 30a. Then, by fitting the opening 32a of the cutting blade 32 into the spindle 30 and fastening the nut 34 to the male screw 30b of the spindle 30, the cutting blade 32 is sandwiched between the flange 30a and the nut 34 and is placed at the tip of the spindle 30. Detachable and fixed.

Explaining with reference to FIG. 2, in the apparatus housing 14, a cassette 46 containing a plurality of wafers 2 supported by an annular frame 8 via an adhesive tape 10 is mounted on a vertically movable cassette mounting table 48. There is. The cassette mounting table 48 is raised and lowered by an elevating means (not shown). Further, the processing apparatus 12 draws out the uncut waiha 2 from the cassette 46 and carries it out to the temporary placement table 50, and also carries in / out means 52 for carrying the cut waha 2 positioned in the temporary placement table 50 into the cassette 46. The first transport means 54 for transporting the uncut waiha 2 carried out from the cassette 46 to the temporary storage table 50 to the chuck table 16, the cleaning means 56 for cleaning the cut waha 2, and the cut waha 2 are provided. A second transport means 58 for transporting from the chuck table 16 to the cleaning means 56 is further provided.

After performing the processing device preparation process for preparing the processing device 12 as described above, a grinding wheel slightly wider than the distance s between the planned division line 4 and the adjacent planned division line 4 is attached to the cutting means 24 for grinding. Carry out the grindstone mounting process. In the grinding wheel mounting step, first, the screws 38 and 42 of the blade cover 28 are loosened, and the second cover member 40 and the blade detection block 44 are removed from the first cover member 36 (see FIG. 4). Next, the male screw 30b of the spindle 30 and the nut 34 are released from the fastening, and the cutting blade 32 is removed from the spindle 30 (see FIG. 5). Next, the opening 60a of the annular grinding wheel 60 is fitted to the spindle 30, and the nut 34 is fastened to the male screw 30b of the spindle 30, so that the annular grinding wheel 60 is attached to the tip of the spindle 30 as shown in FIG. Mounting. The width t (axial thickness) of the grinding wheel 60 slightly wider than the interval s of the planned division line 4 will be described in detail later. For example, the dimension of one side of the device 6 is 5 mm, and the width of the planned division line 4 When is 0.1 mm and the interval s of the scheduled division lines 4 is 5.1 mm, the width t of the grinding wheel 60 may be about 5.2 mm. Then, the second cover member 40 and the blade detection block 44 are fixed to the first cover member 36 by the screws 38 and 42.

After performing the grinding wheel mounting process, the X-axis feeding means is operated to grind the holding surface of the chuck table 16 with the grinding wheel 60, and the Y-axis feeding means is operated to index and feed at the interval s of the scheduled division line 4. A holding surface grinding process is performed to grind the holding surface. To explain with reference to FIG. 7, in the holding surface grinding step, first, the X-axis feeding means is operated to position the chuck table 16 below the cutting means 24. Further, the Y-axis feed means is operated to position the grinding wheel 60 at one end of the chuck table 16 in the Y-axis direction. Although the blade cover 28 is omitted in FIG. 7 for convenience, the blade cover 28 is attached to the cutting means 24 when the holding surface grinding process is performed, and this point is the same in FIGS. 8 and 9. Is. Next, the grinding wheel 60 is rotated by a motor together with the spindle 30 in the direction indicated by the arrow A in FIG. 7. Next, the cutting means 24 is lowered by the Z-axis feeding means, and the grinding wheel 60 is brought into contact with the chuck table 16. Next, the grinding wheel 60 is positioned about 20 μm below the position where the grinding wheel 60 and the chuck table 16 are in contact with each other, and the X-axis feeding means is operated to move the chuck table 16 relative to the cutting means 24 in the X-axis direction. The upper surface of the suction chuck 18 constituting the holding surface of the chuck table 16 is ground by grinding. At the time of grinding, after closing the first valve 17c and opening the second valve 19c, the water source 19b is operated to inject water from the upper surface of the suction chuck 18. This makes it possible to prevent the grinding debris from adhering to the porous suction chuck 18 and causing clogging. At the time of grinding, the cutting water supply source also operates to inject cutting water from the first cutting water supply nozzle 36a and the second cutting water supply nozzle 40a toward the grinding wheel 60 and the suction chuck 18. Next, the Y-axis feed means is operated to index and feed the cutting means 24 relative to the chuck table 16 at the interval s of the scheduled division line 4 in the Y-axis direction. Then, the grinding process and the indexing feed are alternately repeated to grind the entire upper surface of the suction chuck 18. Since the width t of the grinding wheel 60 is slightly wider than the interval s of the scheduled division line 4, the grinding area due to the grinding process is slightly widened in the Y-axis direction by indexing and feeding at the interval s of the scheduled division line 4 in the holding surface grinding process. Since they overlap, the entire upper surface of the suction chuck 18 can be ground. By grinding the upper surface of the suction chuck 18 in this way, the upper surface of the suction chuck 18 corresponding to the swing of the chuck table 16 in the Z-axis direction when the chuck table 16 is machined and fed in the X-axis direction is formed. be able to. That is, even if the chuck table 16 swings in the Z-axis direction when the chuck table 16 is machined and fed in the X-axis direction, the swing of the chuck table 16 is substantially 0 at the machining position where the cutting blade 32 cuts. (The upper surface position of the suction chuck 18 with respect to the cutting blade 32 is constant).

Here, the width t of the grinding wheel 60 and the indexing feed distance in the holding surface grinding process will be described. The smaller the width t of the grinding wheel 60 and the smaller the indexing feed distance in the holding surface grinding process, the smaller the indexing feed distance of the chuck table 16. Although the upper surface of the suction chuck 18 corresponding to the swing in the Z-axis direction can be formed with high accuracy, the number of grinding processes increases and the efficiency deteriorates. On the other hand, as the width t of the grinding wheel 60 is large and the indexing feed distance in the holding surface grinding process is large, the number of grinding processes is reduced and efficiency can be improved, but the accuracy of the upper surface of the suction chuck 18 deteriorates. Resulting in. In this respect, in the illustrated embodiment, the width t of the grinding wheel 60 is slightly wider than the interval s of the scheduled division line 4, and the indexing feed distance in the holding surface grinding step is the interval s of the scheduled division line 4. The upper surface of the suction chuck 18 may be subjected to grinding work a number of times corresponding to the quantity of the scheduled split line 4a in the first direction (the same as the quantity of the scheduled split line 4b in the second direction in the illustrated embodiment). In addition, there is little overlap of the grinding areas due to the grinding process, and the portion of the upper surface of the suction chuck 18 where the scheduled division line 4 is positioned is not ground multiple times. Therefore, it is possible to accurately and efficiently form the upper surface of the suction chuck 18 suitable for cutting the wafer 2 to be cut along the scheduled division line 4.

After performing the holding surface grinding step, the cutting blade mounting step of removing the grinding wheel 60 from the cutting means 24 and mounting the cutting blade 32 is carried out. In the cutting blade mounting step, first, the second cover member 40 and the blade detection block 44 are removed from the first cover member 36. Next, the male screw 30b of the spindle 30 and the nut 34 are released from the fastening, and the grinding wheel 60 is removed from the spindle 30. Next, the opening 32a of the cutting blade 32 is fitted to the spindle 30, and the nut 34 is fastened to the male screw 30b of the spindle 30, so that the cutting blade 32 is attached to the tip of the spindle 30. Then, the second cover member 40 and the blade detection block 44 are fixed to the first cover member 36.

After carrying out the cutting blade mounting step, the first holding step of positioning the scheduled split line 4a formed in the wafer 2 in the first direction parallel to the X-axis direction and holding it on the holding surface of the chuck table 16 is carried out. .. In the first holding step, first, the uncut wafer 2 supported by the annular frame 8 via the adhesive tape 10 is pulled out from the cassette 46 by the carry-in / out means 52 and carried out to the temporary storage table 50. Next, the uncut wafer 2 carried out to the temporary placement table 50 is conveyed to the chuck table 16 by the first conveying means 54. At this time, the scheduled division line 4a in the first direction is positioned parallel to the X-axis direction, and the wafer 2 is placed on the upper surface of the suction chuck 18. Next, after opening the first valve 17c and closing the second valve 19c, the suction source 17b is operated to generate a suction force on the upper surface of the suction chuck 18, so that the wafer 2 is sucked and held, and a plurality of wafers 2 are sucked and held. The annular frame 8 is fixed by the clamp 20. When the wafer 2 is sucked and held by the suction chuck 18, the thickness of the wafer 2 is as thin as several tens to several hundreds of μm, so that the wafer 2 is deformed along the upper surface of the suction chuck 18 ground in the holding surface grinding step.

After performing the first holding step, the first division scheduled line 4a in the first direction is cut in the X-axis direction and indexed and fed in the Y-axis direction to cut the division scheduled line 4a in the first direction. Carry out the cutting process. Explaining with reference to FIG. 8, in the first cutting step, first, the wafer 2 is imaged from above by the image pickup means 22, and the first direction to be cut is based on the image of the wafer 2 captured by the image pickup means 22. The scheduled division line 4a is detected. Next, the chuck table 16 is moved by the X-axis feed means, and the cutting means 24 is moved by the Y-axis feed means, so that the planned division line 4a in the first direction is positioned below the cutting blade 32. Next, the cutting blade 32 is rotated by a motor together with the spindle 30 in the direction indicated by the arrow A in FIG. Next, the cutting means 24 is lowered by the Z-axis feeding means, the cutting edge of the cutting blade 32 is cut into the division scheduled line 4a in the first direction, and the X-axis feeding means is operated to chuck the cutting means 24. By machining and feeding the table 16 relatively in the X-axis direction, the first cutting process for cutting the planned division line 4a in the first direction in the X-axis direction is performed. At the time of the first cutting process, cutting water is injected from the first cutting water supply nozzle 36a and the second cutting water supply nozzle 40a toward the cutting blade 32 and the wafer 2. Next, the Y-axis feed means is operated to index and feed the cutting means 24 relative to the chuck table 16 by the interval s of the scheduled division line 4 in the Y-axis direction. Then, by alternately repeating the first cutting process and the indexing feed, all of the planned division lines 4a in the first direction are cut in the X-axis direction. A portion (first machining line) subjected to the first cutting along the planned division line 4a in the first direction is shown by reference numeral 62a in FIG.

After performing the first cutting step, the wafer 2 is separated from the chuck table 16 and the planned division line 4b in the second direction formed on the wafer 2 is positioned parallel to the X-axis direction on the holding surface of the chuck table 16. A second holding step of holding is carried out. In the second holding step, first, the operation of the suction source 17b is stopped or the first valve 17c is closed to release the suction force of the suction chuck 18, and the annular frame 8 is released from being fixed by the clamp 20. Next, the wafer 2 is raised by the first transport means 54 to be detached from the chuck table 16. Next, the wafer 2 is rotated 90 degrees, the scheduled division line 4b in the second direction is positioned parallel to the X-axis direction, and the wafer 2 is placed on the upper surface of the suction chuck 18. Then, the wafer 2 is sucked and held by the suction chuck 18, and the annular frame 8 is fixed by the plurality of clamps 20. Also in the second holding step, when the wafer 2 is sucked and held by the suction chuck 18, the wafer 2 is deformed along the upper surface of the suction chuck 18. After the waha 2 is separated from the chuck table 16, the chuck table 16 is rotated 90 degrees without rotating the waha 2 90 degrees, the waha 2 is repositioned on the chuck table 16, and then the chuck table 16 is rotated 90 degrees. By doing so and returning to the original position, the scheduled division line 4b in the second direction may be positioned parallel to the X-axis direction.

After performing the second holding step, the second planned division line 4b in the second direction is cut in the X-axis direction and indexed and fed in the Y-axis direction to cut the planned division line 4b in the second direction. Carry out the cutting process. Explaining with reference to FIG. 9, in the second cutting step, as in the first cutting step, first, the wafer 2 is imaged from above by the image pickup means 22, and the second cutting step is based on the image of the image of the wafer 2. The planned division line 4b in the direction is detected. Next, by moving the chuck table 16 and the cutting means 24, the planned division line 4b in the second direction is positioned below the cutting blade 32. Next, the cutting blade 32 is rotated by a motor together with the spindle 30 in the direction indicated by the arrow A in FIG. Next, the cutting means 24 is lowered by the Z-axis feeding means, the cutting edge of the cutting blade 32 is cut into the split scheduled line 4b in the second direction, and the X-axis feeding means is operated to chuck the cutting means 24. By machining and feeding the table 16 relatively in the X-axis direction, a second cutting process for cutting the scheduled division line 4b in the second direction in the X-axis direction is performed. Also during the second cutting process, cutting water is injected from the first cutting water supply nozzle 36a and the second cutting water supply nozzle 40a toward the cutting blade 32 and the waha 2. Next, the Y-axis feed means is operated to index and feed the cutting means 24 relative to the chuck table 16 by the interval s of the scheduled division line 4 in the Y-axis direction. Then, by alternately repeating the second cutting process and the indexing feed, all of the planned division lines 4b in the second direction are cut in the X-axis direction. A portion (second processing line) subjected to the second cutting along the planned division line 4b in the second direction is shown by reference numeral 62b in FIG.

After performing the second cutting step, the cut wafer 2 is conveyed from the chuck table 16 to the cleaning means 56 by the second conveying means 58. Next, the cut wafer 2 is washed by the washing means 56 to remove cutting chips and cutting water, and the wafer 2 is dried. Next, the washed wafer 2 is transported to the temporary storage table 50 by the first transport means 54. Then, the cut wafer 2 positioned on the temporary storage table 50 is carried into the cassette 46 by the carry-in / out means 52.

As described above, in the illustrated embodiment, the upper surface of the suction chuck 18 is ground in the holding surface grinding step so as to correspond to the swing of the chuck table 16 in the Z-axis direction when the chuck table 16 is machined and fed in the X-axis direction. Further, since the wafer 2 held by the suction chuck 18 in the first and second holding steps is deformed along the upper surface of the suction chuck 18, the chuck table 16 is machined and fed in the X-axis direction. The swing of the chuck table 16 is substantially 0 (the upper surface position of the suction chuck 18 with respect to the cutting blade 32 is constant) at the machining position where the cutting blade 32 cuts even if the swing is in the Z-axis direction. Depth can be maintained with high accuracy. Therefore, in the illustrated embodiment, in the first cutting step and the second cutting step, for example, from the front surface 2a to the back surface of the wafer 2 along the planned division line 4a in the first direction and the planned division line 4b in the second direction. The wafer 2 can be completely cut and the adhesive tape 10 can be cut to a depth of about 5 μm with high precision.

2: Wafer 2a: Wafer surface 4: Scheduled split line 4a: Scheduled split line in the first direction 4b: Scheduled split line in the second direction s: Spacing of scheduled split lines 12: Machining device 16: Chuck table 60: Grinding wheel t: Width of grinding wheel

Claims (1)

A method for processing a wafer in which a plurality of devices are partitioned by a planned division line in a first direction and a planned division line in a second direction intersecting the first direction, and a wafer formed on the surface is divided into individual devices. And
A chuck table having a holding surface for holding a wafer, a cutting means provided with a detachable cutting blade for cutting a wafer held on the chuck table, and a chuck table and the cutting means relatively in the X-axis direction. Prepare a machining apparatus provided with at least an X-axis feed means for machining and feeding the chuck table and a Y-axis feed means for indexing and feeding the chuck table and the cutting means relative to the Y-axis direction orthogonal to the X-axis direction. Processing equipment preparation process and
The grinding wheel mounting process of mounting a grinding wheel slightly wider than the distance between the scheduled split line and the adjacent scheduled split line to the cutting means, and
The holding surface for grinding the holding surface by operating the X-axis feeding means to grind the holding surface of the chuck table with the grinding wheel and operating the Y-axis feeding means to index and feed at intervals of the scheduled division lines. Grinding process and
The cutting blade mounting process of removing the grinding wheel from the cutting means and mounting the cutting blade,
The first holding step of positioning the planned division line in the first direction formed on the wafer parallel to the X-axis direction and holding it on the holding surface of the chuck table,
The first cutting step of cutting the planned division line in the first direction in the X-axis direction and indexing and feeding in the Y-axis direction to cut the planned division line in the first direction.
A second holding step in which the wafer is separated from the chuck table and the planned division line in the second direction formed on the wafer is positioned parallel to the X-axis direction and held on the holding surface of the chuck table.
A second cutting step of cutting the planned division line in the second direction in the X-axis direction and indexing and feeding in the Y-axis direction to cut the planned division line in the second direction.
Wafer processing method consisting of at least.

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