JP5539023B2 - Wafer processing method - Google Patents

Description

  The present invention relates to a method for efficiently performing the remaining cutting of a wafer after replacement of the cutting blade when the cutting blade is broken during cutting of the wafer by the cutting blade.

  A wafer such as a semiconductor wafer is cut along a planned division line by a cutting device or the like and divided into individual devices. The cutting apparatus includes a chuck table for holding a wafer having a predetermined division line formed on a surface thereof, a cutting means having a cutting blade for cutting the wafer held on the chuck table, and an image of the wafer held on the chuck table for cutting. Alignment means for detecting the area to be cut, cutting feed means for cutting and feeding so that the chuck table, cutting means and alignment means move relatively in the cutting feed direction, and the cutting means, alignment means and chuck table are relative to each other. And an indexing feeding means for indexing and feeding so as to move in the indexing feeding direction orthogonal to the cutting feed direction. Two cutting means are arranged with the cutting blades facing each other, and dual cutting that processes the wafer two lines at a time, or full cut along the groove after forming a notch groove of a predetermined depth from the wafer surface The wafer is divided into individual devices efficiently by step cutting or the like for dividing the wafer (Patent Document 1).

  In the cutting apparatus configured as described above, the cutting blade is generally formed by solidifying abrasive grains made of diamond or the like with a bonding agent. If the cutting blade breaks while cutting the wafer, remove the wafer to be cut from the chuck table and replace the damaged cutting blade with a new cutting blade. A cutting operation called pre-cut is performed in which a dummy wafer formed of substantially the same quality material is cut and a new cutting blade is fitted to the wafer. Then, the cutting interrupted wafer whose cutting operation has been interrupted due to breakage is remounted on the chuck table, and the remaining uncut area is cut.

JP H11-26402 A

  However, when the cutting interrupted wafer is placed on the chuck table again, it is impossible to place the wafer at the exact same position as the placement position before removal from the chuck table due to an error during conveyance in the cutting apparatus. Even when the cutting interruption position is recorded in the recording means, it is difficult to automatically position the imaging unit in the final cutting groove in which the cutting operation is interrupted and perform alignment with the cutting blade. Therefore, in practice, the operator manually searches for the final cutting groove, detects the uncut region, and performs cutting of the uncut region. There is a problem that it is complicated and inefficient.

  The present invention has been made in view of the above points, and its purpose is to search for a final cutting groove even when a wafer whose cutting operation has been interrupted is once removed from the chuck table and placed on the chuck table again. It is another object of the present invention to provide a wafer cutting method capable of efficiently cutting an uncut region.

  The present invention relates to a chuck table for holding a wafer having a line to be divided on the surface, a cutting means having a cutting blade for cutting the wafer held on the chuck table, and an image of the wafer held on the chuck table. An alignment means for detecting a region to be cut, a cutting feed means for cutting and feeding so that the chuck table, the cutting means and the alignment means move in the cutting feed direction, and the cutting means, the alignment means and the chuck table. Cutting using a cutting device including an indexing feeding means for indexing and feeding so as to move in an indexing feeding direction that is relatively perpendicular to the cutting direction, and the cutting operation is interrupted while the wafer is being cut by the cutting means, and the cutting operation is interrupted. After removing the interrupted wafer from the chuck table, remove the interrupted wafer. The present invention relates to a wafer processing method for mounting on a chuck table and cutting an uncut region of a cutting interrupted wafer, a wafer remounting step for remounting a cutting interrupted wafer removed from a chuck table to a chuck table, and a cutting interrupted wafer A cutting groove on the outer periphery on the cutting start side is imaged by an alignment means, and a final cutting groove searching step for searching for a final cutting groove of a cutting interrupted wafer and an uncut area cutting step for cutting an uncut area are configured.

  The wafer processing method includes a recording step of recording the position information of the final cutting groove of the cutting interrupted wafer on the recording means before removing the cutting interrupted wafer from the chuck table, and the recording step is recorded in the final cutting groove searching step. It is desirable to search the final cutting groove by the alignment means using the position information of the final cutting groove as a starting point.

  In most cases, the cutting blade breaks during the cutting of the division line, and in many cases, a cutting groove is formed on the outer periphery of the wafer on the cutting start side of the broken division line. Therefore, in the present invention, by searching for the cutting groove on the outer peripheral portion of the wafer on the cutting start side, the complexity of the search is eliminated, and the final cutting groove can be searched efficiently. Further, since the final cutting groove is searched based on the position information of the final cutting groove recorded in advance, it is possible to more efficiently cut the uncut region.

It is a perspective view which shows an example of a cutting device. It is explanatory drawing which shows the structure for detecting the failure | damage of the cutting blade of a cutting blade. It is explanatory drawing which shows typically the mechanism for detecting the positional information on a chuck table and two cutting means. It is explanatory drawing which shows the positional relationship of a cutting blade and an imaging part. It is a top view which shows an example of a wafer. It is explanatory drawing which shows the state which aligned the cutting blade to the line of the edge part of a wafer. It is explanatory drawing which showed typically the state which cuts the line of a wafer. It is a flowchart which shows 1st embodiment of this invention. It is explanatory drawing which shows the state of a precut. It is explanatory drawing which shows the state of search of the last cutting groove. It is explanatory drawing which shows typically the state which cuts an uncut area | region. It is a flowchart which shows 2nd embodiment of this invention. It is explanatory drawing which shows the state of search of the last cutting groove.

  A cutting apparatus 1 shown in FIG. 1 is an apparatus for cutting a workpiece held on a chuck table 2 using two cutting means 3a and 3b.

  The chuck table 2 is formed of a porous member, can suck and hold the workpiece by negative pressure, and is driven by the cutting feed means 4 to be movable in the X direction. The X direction is a cutting feed direction that is a direction in which the workpiece moves when the workpiece is cut.

  The cutting feed means 4 includes a ball screw 40 having a rotation axis in the X-axis direction, a guide rail 41 disposed in parallel with the ball screw 40, a motor 42 connected to one end of the ball screw 40, and a lower portion serving as a guide. A moving base 43 in which a nut (not shown) is engaged with the ball screw 40 and an X scale 44 for recognizing the position of the chuck table 2 in the X direction is provided. When the ball screw 40 is driven to rotate, the moving base 43 is guided by the guide rail 41 and moves in the X direction, whereby the chuck table 2 supported by the moving base 43 also moves in the X direction. It has become.

  Since the two cutting means 3a and 3b are configured in the same manner, they will be described with common reference numerals. The cutting means 3a, 3b rotate the cutting blade 30 about the cutting blade 30 that cuts the workpiece held on the chuck table 2 and the Y direction that is a direction orthogonal to the horizontal direction with respect to the X direction as a rotation axis. And a spindle 31. In addition, alignment means 32a and 32b are fixed to the side portions of the cutting means 3a and 3b, respectively. The alignment means 32a and 32b are provided with image pickup units 320a and 320b for picking up the image below.

  The two cutting means 3a, 3b and the alignment means 32a, 32b are respectively driven by the two cutting feed means 5a, 5b and are movable in the Z direction, and are also driven by the two index feeding means 6a, 6b, respectively. Thus, it can move in the Y direction.

  Since the two cut-in feeding means 5a and 5b are configured in the same manner, they will be described with common reference numerals. The cutting feed means 5 includes a support base 50 that supports the cutting means 3a and 3b, and a motor 51 that raises and lowers the support base 50. As the support base 50 is raised and lowered, the cutting means 3a and 3b are also raised and lowered. It is the composition to do.

  Since the two indexing and feeding means 6a and 6b are configured in the same manner, they will be described with common reference numerals. The cutting feed means 6 includes a ball screw 60 having a rotation axis in the Y-axis direction, a guide rail 61 arranged in parallel with the ball screw 60, a pulse motor 62 connected to one end of the ball screw 60, and a side portion. Includes a moving base 63 in which a nut (not shown) is engaged with the ball screw 60 and a Y scale 64 for recognizing the position of the cutting means 3a and 3b in the Y direction. When the ball screw 60 driven by the pulse motor 62 rotates, the moving base 63 is guided by the guide rail 61 and moves in the Y-axis direction to move the cutting means 3a and 3b in the Y direction. ing.

  The operations of the cutting feed means 4, the cutting feed means 5 and the index feed means 6 are controlled by a control means 10 having a CPU. Therefore, the position in the X direction of the holding table 2 driven by the cutting feed means 4 and the positions in the Y direction and Z direction of the cutting means 3a and 3b driven by the cutting feed means 5 and the index feed means 6 are controlled by the control means 10. Controlled by. The control means 10 records the position information necessary for controlling the holding table 2 and the cutting means 3a and 3b in the recording means 11 having a storage element such as a memory, and reads out the recorded contents as necessary for use in the control. can do.

  On the front side of the movable range of the chuck table 2, a wafer cassette 7 that can accommodate a plurality of wafers W that are workpieces is disposed. The wafer cassette 7 can be lifted and lowered by the lifting mechanism 70. The wafer W accommodated in the wafer cassette 7 is attached to the tape T, and is in a state of being supported integrally with the ring-shaped frame F attached to the peripheral edge of the tape T.

  A cleaning unit 8 for cleaning the wafer W after cutting is disposed on the rear side of the movable range of the chuck table 2. The cleaning unit 8 includes a rotary table 80 that holds and rotates the wafer W, and a cleaning liquid ejection unit 81 that ejects a cleaning liquid to the wafer W held on the rotary table 80.

  The wafer W accommodated in the wafer cassette 7 is transferred to the chuck table 2 by a transfer means (not shown). Further, the wafer held by the chuck table 2 and cut is also transferred to the cleaning means by a transfer means (not shown).

  For example, as shown in FIG. 2, the cutting blade 30 constituting the cutting means 3 a and 3 b is configured such that a cutting blade 300 is sandwiched by a flange 301, and the cutting blade 300 protruding from the flange 301 to the outer peripheral side is the workpiece. Cutting is performed by cutting into. A light emitting unit 302a and a light receiving unit 302b are disposed at positions facing both surfaces of the cutting blade 300, respectively. The light receiving unit 302b is connected to the control unit 10, and the control unit 10 emits light emitted from the light emitting unit 302a. Is received by the light receiving unit 302b, it is determined that the cutting blade 300 is damaged or the like, and processing according to the determination result can be performed.

  As shown in FIG. 3, sensors 90, 91a, and 9b for reading the distances from the origins of the X scale 44 and the Y scale 64 are disposed on the chuck table 2 and the cutting means 3a and 3b, respectively. The value read by the sensor 90 is recognized by the control means 10 as the X coordinate of the chuck table 2, and the value read by the sensors 91a and 91b is recognized as the Y coordinate of the cutting means 3a and 3b. The cutting blade constituting the cutting means 3a is referred to as a cutting blade 30a, and the cutting blade constituting the cutting means 3b is referred to as a cutting blade 30b.

  As shown in FIG. 4, reference lines 321a and 321b extending in the X direction are respectively formed on the objective lens of the imaging unit 320a of the alignment unit 32a and the imaging unit 320b of the alignment unit 32b, and the X direction of the reference line 321a is formed. The cutting blade 300a of the cutting blade 30a is positioned on the extended line of the above, and the cutting blade 300b of the cutting blade 30b is positioned on the extended line of the reference line 321b in the X direction in advance. The cutting blade 30a is attached to the spindle 31a, and the cutting blade 30b is attached to the spindle 31b.

  Below, the case where the wafer W shown, for example in FIG. 5 is cut using the cutting device 1 shown in FIG. 1 is demonstrated. The wafer W shown in FIG. 5 has a device D in a region partitioned by division planned lines (hereinafter referred to as “lines”) A1 to A17 formed in one direction and lines B1 to B19 orthogonal to the lines A1 to A17. Formed and configured. When cutting the wafer W, information such as the number of lines and the interval between adjacent lines is input to the control means 10 in advance, and the control means 10 can perform various controls with reference to the information.

(Alignment step)
First, the Y coordinate of the line A1 formed at the end of the wafer W in FIG. 5 is detected by the alignment unit 32a shown in FIG. 1, and the Y of the line A17 formed at the end of the wafer W by the alignment unit 32b. Detect coordinates.
As shown in FIG. 6, the cutting blade 300a of the cutting blade 30a is positioned at the detected position of the Y coordinate of the line A1 and on the extended line in the X direction of the line A1. Similarly, the cutting blade 30b is positioned at the position of the Y coordinate of the line A17 and on the extended line in the X direction of the line A17. In practice, the tape and the frame F shown in FIG. 1 are present around the wafer, but the tape and the frame F are not shown in FIG.

(Cutting step)
Then, while rotating the cutting blades 30a and 30b at a high speed, the cutting means 3a and 3b are lowered at the cutting start position (the left end of the two-dot chain line shown in FIG. 6), and the chuck table 2 holding the wafer W is cut and fed in the X direction. Then, when the cutting blades 30a and 30b are cut into the lines A1 and A17, respectively, and the cutting feed is further performed, the lines A1 and A17 are cut, and cutting grooves G1 and G17 are formed as shown in FIG. . The cutting here includes both complete cutting in which the cutting blade penetrates to the back surface of the wafer W and incomplete cutting in which a cutting groove having a predetermined depth is formed by cutting the wafer W to a predetermined depth.

  Next, the chuck table 2 is returned to the cutting start position (the left end of the two-dot chain line shown in FIG. 6), and the cutting means 3a and 3b are indexed and fed in the direction in which they approach each other, and the cutting means is provided by an interval between adjacent lines. By indexing and feeding 3a and 3b in the Y direction, the cutting blade 30a is positioned on the extension line of the line A2, and the cutting blade 30b is positioned on the extension line of the line A16. Similarly to the above, the chuck table 2 is cut and fed in the X direction, and the cutting means 3a and 3b are lowered while the cutting blades 30a and 30b are rotated at high speed, whereby the cutting blades 30a and 30b that rotate at high speed are lined up respectively. When cutting is performed at A2 and A16 and further cutting feed is performed, the lines A2 and A16 are cut to form cutting grooves G2 and G16, respectively. In this way, the two cutting means 3a and 3b are indexed and fed, and the line is cut in order two by two while the chuck table 2 is cut and fed. Thus, the cutting grooves G3, G15, G4, and G14 are sequentially formed.

  In the process of cutting the line in this way, the cutting blades 300a and 300b of the cutting blades 3a and 3b shown in FIG. 4 may be damaged. In this case, the cutting is interrupted and a new cutting blade is used. Cutting must be resumed after replacement.

  When the cutting blade of any of the cutting blades is damaged, the light receiving unit 302b shown in FIG. 2 receives light from the light emitting unit 302a, so that the control means 10 detects that the cutting blade is damaged. . For example, as shown in FIG. 7, when the cutting blade 300a of the cutting blade 30a is broken during the cutting of the line A5, the control means 10 recognizes the breakage of the cutting blade 300a at that time, but the cutting blade 30b If the cutting blade 300b is not damaged, the cutting feed is continued and cutting is performed to the end for the line A13. If the cutting blade 30a is damaged, the cutting feed is performed even if the cutting feed is performed. However, under the control of the control means 10, the cutting means 3a can be raised and the cutting blade 30a can be retracted when the cutting blade 300a is damaged.

  Hereinafter, the processing after the cutting blade is broken will be described separately for the first embodiment and the second embodiment.

(1) First Embodiment Hereinafter, the first embodiment will be described along the flowchart of FIG.
(1-1) Recording step (step S1)
When the cutting blade 300a is damaged, the control means 10 records the position information of the cutting means 3a and 3b at that time in the recording means 11. This position information is recognized, for example, as Y coordinates Y5 and Y13 shown in FIG.

(1-2) Pre-cut step (Step S2)
When the recording step is completed, the chuck table 2 is returned to the initial position, a wafer being cut (hereinafter referred to as “cutting interrupted wafer W1”) is removed from the chuck table 2, and the damaged cutting blade 30a is removed from the spindle 31a. Then, a new cutting blade 30aa shown in FIG. 9 is mounted on the spindle 31a, and a dummy wafer DW made of the same material as the wafer W is placed on the chuck table 2 as shown in FIG. When the cutting blade 30aa is attached, adjustment is performed so that the reference line 321a of the imaging unit 320a constituting the alignment means 32a is positioned on the extension line in the X direction of the cutting blade 30aa, as shown in FIG.

  Next, as shown in FIG. 9, the chuck wafer 2 sucks and holds the dummy wafer DW, cuts and feeds the dummy wafer DW in the X direction, and cuts the dummy wafer DW while rotating the cutting blade 30aa at a high speed. Pre-cutting is performed to make the blade 30aa conform to the material of the cutting interrupted wafer W1.

(1-3) Wafer remounting step (step S3)
After the pre-cutting of the cutting blade 30aa, the dummy wafer DW is removed from the chuck table 2, and the cutting interrupted wafer W1 shown in FIG. 10 is remounted and held on the chuck table 2. At the time of such remounting, the line where the cutting is interrupted is directed to the X direction.

(1-4) Final cutting groove searching step (step S4)
As preparation for resuming the cutting of the cutting interrupted wafer W1, the control means 10 reads the Y coordinate information Y5 and Y13 of the cutting means 3a and 3b recorded in the recording means 11 in the recording step, respectively. Then, as shown in FIG. 10, the image pickup unit 320a is moved to the coordinate Y5, the image pickup unit 320b is moved to the coordinate Y13, the cut start side for each line at both Y coordinates, and the left end side of the wafer W in FIG. Images are taken from the outer periphery.

  Next, the control means 10 searches for the cutting grooves G5 and G13 formed in the lines A5 and A13 of the cutting interrupted wafer W. Since the placement position of the cutting interrupted wafer W1 may be deviated from that before the interruption, for example, the line indicated by a two-dot chain line in FIG. 10 is the position before the interruption, and the line indicated by the solid line is reproduced again. In the case of the line after placement, since the Y coordinates of A5 and A13 before the interruption are Y5 and Y13, the lines A5 and A13 after the placement are not coincident with the coordinates Y5 and Y13. Therefore, even if the imaging units 320a and 320b are positioned at the coordinates Y5 and Y13, the imaging unit 320a cannot capture the cutting groove G5 formed in the line A5, and the imaging unit 320b captures the cutting groove G13 formed in the line A13. Imaging may not be possible. In this case, under the control of the control unit 10, the image pickup units 320a and 320b are finely adjusted in the Y direction to search for a cutting groove in the vicinity thereof.

  When the cutting groove G5 enters the field of view of the imaging unit 320a indicated by the solid line and the cutting groove G5 is recognized by the control means 10, as shown in FIG. 10, the imaging unit 320a is moved along the outer periphery on the cutting start side in the Y direction. If one index is indexed and fed (at a position indicated by reference numeral 320a ″ in FIG. 10) and it is recognized that there is no cutting groove, it is determined that the cutting groove G5 is the final cutting groove. Next, the chuck table 2 is moved in the X direction to position the imaging unit 320a on one end side of the cutting interrupted wafer W1 (position indicated by reference numeral 320a 'in FIG. 10), and image one end side of the cutting groove G5. At this time, since the cutting groove G5 is not detected at the position (320a ') on one end side, the control means 10 determines that the cutting groove G5 is a line where cutting is interrupted. At that time, the position of the imaging unit 320a in the Y direction is not moved, and the chuck table 2 is returned to the initial position.

  On the other hand, the same search is performed for the cutting means 3b. When the cutting groove G13 is imaged by the imaging unit 320b indicated by the solid line and detected by the control means 10, as shown in FIG. 10, the imaging unit 320b is indexed and fed in the Y direction along the outer periphery on the cutting start side. When the image is taken (at a position indicated by reference numeral 320b ″ in FIG. 10) and it is recognized that there is no cutting groove, it is determined that the cutting groove G13 is the final cutting groove. At that time, the position of the imaging unit 320b in the Y direction is not moved, the chuck table 2 is moved in the X direction, and the imaging unit 320b is positioned on one end side of the cutting interrupted wafer W1 (a position indicated by reference numeral 320b ′ in FIG. 10). Then, one end side (320b ′) of the cutting groove G13 is imaged. At this time, since the control means 10 detects the cutting groove G13 at the position 320b ', it is determined that the cutting groove G13 is not a line in the middle of cutting.

  In this way, the cutting grooves G5 and G13 are recognized by the control means 10 as the final cutting groove before cutting is interrupted. As shown in FIG. 4, the reference line 321a of the imaging unit 320a and the cutting blade 300a of the cutting blade 30a have the same Y coordinate, and the reference line 321b of the imaging unit 320b and the cutting blade 300b of the cutting blade 30b are Y Since the coordinates are equal, the cutting grooves G5 and G13 and the cutting blades 300a and 300b of the cutting blades 30a and 30b are automatically matched by matching the cutting grooves G5 and G13 with the reference lines 321a and 321b of the imaging units 320a and 320b. Have the same Y coordinate.

(1-5) Uncut region cutting step (step S5)
As shown in FIG. 11, the cutting blade 30aa is positioned on the extension line of the line A5. On the other hand, the cutting blade 30b is indexed and fed in the Y direction by one line from the line A13 where the cutting is completed, and is positioned on the line A12. Then, in this state, the cutting blades 30aa and 30b are rotated at a high speed to cut and feed the cutting interrupted wafer W1, and the cutting means 3a and 3b are lowered to cut the lines A5 and A12 as shown in FIG. About line A5, it will cut again to the middle.

  Next, each line is sequentially cut while indexing and feeding the cutting means 3a, 3b in the Y direction at intervals of adjacent lines. The center line is cut using any one of the cutting means because the two cutting means 3a and 3b may cause a collision with each other.

  When the line A1-A17 is cut in this way, the chuck table 2 is rotated by 90 degrees, and the same cutting is performed on the line B1-19 shown in FIG. If any of the cutting blades is damaged in the middle, a recording step, a pre-cut step, a wafer remounting step, a final cutting groove searching step, and an uncut region cutting step are executed as described above.

  In the first embodiment, the coordinate information of the final cutting groove at the time of cutting interruption is recorded and the cutting is restarted from the coordinates. However, the search of the cutting restart position is performed by a method using the coordinate information. It is not limited. For example, in the recording step, information on the number of lines that have been cut and the distance from the key pattern on the surface of the cutting interrupted wafer to the final cutting groove is recorded as the position information of the final cutting groove of the cutting interrupted wafer (key pattern and Is a part of the circuit pattern formed on the cut interrupted wafer). In the final cutting groove search step, first, the key pattern on the surface of the cutting interrupted wafer may be detected, and the final cutting groove may be searched by using the recorded information.

(2) Second Embodiment The second embodiment will be described along the flowchart of FIG.
(2-1) Precut step (step S6)
Even if breakage of the cutting blade 30a is detected, the recording step performed in the first embodiment is not performed, the chuck table 2 is returned to the initial position, and a wafer being cut (hereinafter referred to as “cutting interrupted wafer W1”). ) Is removed from the chuck table 2, and the damaged cutting blade 30a is removed from the spindle 31a. Others are the same as those in the first embodiment.

(2-2) Wafer remounting step (Step S7)
Similar to the first embodiment, after the pre-cutting of the cutting blade 30aa is completed, the dummy wafer DW is removed from the chuck table 2, and the cutting interrupted wafer W1 is remounted and held on the chuck table 2.

(2-3) Final cutting groove detection step (step S8)
Since the positions of the cutting means 3a and 3b at the time when the cutting blade 30a is broken are not recorded, it is sequentially searched by a search method which line the cutting blade 30a is broken during. As shown in FIG. 13, the two imaging units 320a and 320b are positioned on the outer periphery of the cutting start side with respect to each line of the cutting interrupted wafer W1, and the imaging units 320a and 320b are indexed and fed in the Y direction (in FIG. 13). 320a ₁ , 320a ₂ , 320a ₃ ..., 320b ₁₇ , 320b ₁₆ , 320b ₁₅ ... (Sequentially moved from the cutting grooves G 1 and G 17 on the outer peripheral portion on the cutting start side by image processing) The cutting groove is detected.

  Then, when reaching a line having no cutting groove, the last detected cutting groove is imaged by returning by one line interval. In the example of FIG. 13, the cutting groove G5 is the last cutting groove detected last by the imaging unit 320a, and the cutting groove G13 is the last cutting groove detected last by the imaging unit 320b.

When the cutting grooves G5 and G13 are detected in this way, next, the cutting interrupted wafer W1 is imaged while dividing the region into two in the X direction, and the ends of the cutting grooves G5 and G13 are searched by the binary search method. To do. The cutting interrupted wafer W1 is moved in the X direction, and first, the intermediate positions of the lines A5 and A13 (positions indicated by reference numerals 320a ₅ ′ and 320b ₁₃ ′ in FIG. 13) are imaged using the imaging units 320a and 320b. At this time, since a cutting groove is not detected at the imaging location for the line A5, the control means 10 determines that the line A5 is a line in which cutting is interrupted. On the other hand, as for the cutting groove 13, since the cutting groove G13 is detected even at an intermediate position (a position indicated by reference numeral 320b ₁₃ 'in FIG. 13), the end of the other side ( _320b13 ''in FIG. 13) is imaged. To do. Since the cutting groove G13 is also detected at the end 320 _b13 ″, the control means 10 recognizes that the cutting groove G13 has been completely cut. Note that a method other than the sequential search method or the binary search method may be used for searching the cutting groove. In addition, when the number of lines is large, it is desirable to use a binary search method for detecting the final cutting groove.

(2-4) Uncut information acquisition step (step S9)
Since the control means 10 recognizes which line has been cut in the final cutting groove search step, it determines that the remaining lines are uncut. Moreover, the control means 10 calculates | requires the number of uncut lines by subtracting the number of cut lines from the information on the number of lines inputted beforehand before cutting.

(2-5) Final cutting groove cutting step (step S10)
The control means 10 indexes and feeds the cutting means 3b in the Y direction by the line interval, and as shown in FIG. 11, the cutting blade 30b is positioned on the extension line of the uncut line A12 and the cutting blade 30aa is being cut. It is positioned on the extension of the line A5. 11, as in the first embodiment, the cutting blades 30aa and 30b are rotated at a high speed in this state, the chuck table 2 is cut and fed, and the cutting means 3a and 3b are lowered to perform line cutting. A5 and A12 are cut. About line A5, it will cut again to the middle. Others are the same as in the first embodiment.

  Since the cutting blade is often broken during the cutting of the line, a cutting groove is often formed on the cutting start side. In both the first embodiment and the second embodiment described above, the cutting groove is searched for at the end on the cutting start side with respect to the wafer, so that the final cutting groove is reliably and efficiently detected. be able to. In the first embodiment, the position information of the cutting groove when cutting is interrupted in the recording step is stored, and the cutting is restarted based on the information, which is more efficient.

1: Cutting device 2: Chuck table 3a, 3b: Cutting means 30, 30a, 30b: Cutting blades 300, 300a, 300b: Cutting blade 301: Flange 302a: Light emitting unit 302b: Light receiving units 31, 31a, 31b: Spindle 32a, 32b: Alignment means 320a: 320b: Imaging units 321a, 321b: Reference line 4: Cutting feed means 40: Ball screw 41: Guide rail 42; Motor 43: Moving base 44 X scale 5a, 5b: Cutting means 50: Support base Table 51: Motor 6a, 6b: Index feed means 60: Ball screw 61: Guide rail 62: Motor 63: Moving base 64: Y scale 7: Wafer cassette 70: Lifting mechanism 8: Cleaning means 80: Rotary table 81: Cleaning liquid Ejecting means 10: Control means 11: Recording means W: Eha A1~A17, B1~B19: dividing lines D: device G1~G5, G13~G17: cut groove T: Tape F: frame W1: Cutting interrupted wafers DW: dummy wafers

Claims (2)

A chuck table for holding a wafer on which a line to be divided is formed, a cutting means having a cutting blade for cutting the wafer held on the chuck table, and imaging and cutting the wafer held on the chuck table An alignment means for detecting an area to be cut, a cutting feed means for cutting and feeding the chuck table, the cutting means and the alignment means so as to move relatively in the cutting feed direction, the cutting means and the alignment means, The cutting operation is interrupted during the cutting of the wafer by the cutting means, using a cutting device including an indexing feeding means for indexing and feeding so that the chuck table moves in an indexing feeding direction orthogonal to the cutting direction. And after the cutting interrupted wafer whose cutting operation has been interrupted is removed from the chuck table, The cutting interruption wafer placed on the chuck table, a processing method of a wafer cutting uncut region of the cutting interruption wafer,
A wafer remounting step of remounting the cutting interrupted wafer removed from the chuck table on the chuck table;
A final cutting groove search step of imaging the cutting groove on the outer periphery of the cutting interrupted wafer on the cutting start side with the alignment means and searching for the final cutting groove of the cutting interrupted wafer;
An uncut area cutting step for cutting the uncut area;
A wafer processing method comprising: Before removing the cutting interrupted wafer from the chuck table, including a recording step of recording position information of the final cutting groove of the cutting interrupted wafer on a recording means,
In the final cutting groove search step, the final cutting groove is searched for by the alignment means starting from the position information of the final cutting groove recorded in the recording step.
The wafer processing method according to claim 1.

Images