JP2017100231A - Method for dividing work-piece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for dividing a work-piece which can divide the work-piece with good precision.SOLUTION: The method for dividing a plate-like work-piece (11) having a first surface (11a) and a second surface (11b) includes: a first cutting step for making a cutting blade (6) to cut into the first surface of the work-piece to form a cut groove (11c) having a depth at which the groove does not reach the second surface, along a first direction of the work-piece; a groove (11d) for alignment forming step for making a cutting blade (8) to cut into the second surface of the work-piece to form two grooves (11d) for alignment with a depth at which the groves reach the cut groove, along a second direction crossing the first direction; an alignment step for detecting a position and a direction of the cut groove from the second surface side, on the basis of a portion of the cut groove exposed to a bottom part of the groove for alignment; and a second cutting step for making the cutting blade to cut into the second surface on the basis of the position and the direction of the cut groove detected in the alignment step so as to cut the work-piece along the cut groove.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a dividing method for dividing a plate-shaped workpiece.

  When dividing a package substrate, a ceramic substrate, or the like into a plurality of chips, for example, a cutting device including an annular cutting blade is used. By rotating the cutting blade and cutting it into the planned division lines (streets) set for these plate-like workpieces, this workpiece is cut along the planned division lines, into a plurality of chips. Can be divided.

  By the way, electronic components such as piezoelectric elements incorporated in various sensors (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3), for example, process the above-described plate-shaped workpiece into an elongated prismatic shape. Can be formed. Also in this case, a cutting device provided with an annular cutting blade is used (for example, refer to Patent Document 4).

Japanese Patent Laid-Open No. 10-117399 JP 11-318893 A JP 2001-178719 A JP2013-129024A

  As described above, when a workpiece is processed into an elongated prismatic shape, the width of the kerf (cut) formed is sufficiently narrower (for example, 1/25 or less) than the thickness of the workpiece. Use a thin cutting blade. However, such a thin cutting blade has a problem that it is easy to bend by a load during processing and it is difficult to maintain processing accuracy.

  In order to solve this problem, a cutting blade is cut from the first surface side to a depth of about half the depth of the work piece to form a cutting groove, and then cut from the second surface side according to the cutting groove. A dividing method in which a workpiece is cut by cutting a blade has been studied. However, in this division method, the position of the cutting groove formed on the first surface side cannot be easily detected from the second surface side, and therefore the cutting position on the second surface side is likely to shift.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a method of dividing a workpiece that can divide the workpiece with high accuracy.

  According to one aspect of the present invention, there is provided a dividing method in which a plate-like workpiece having a first surface and a second surface opposite to the first surface is divided by a cutting blade. A first holding step for holding the second surface side of the workpiece with a chuck table so as to expose the surface of the workpiece, and cutting the first surface of the workpiece after performing the first holding step. A first cutting step of cutting a blade to form a cutting groove having a depth that does not reach the second surface along the first direction of the workpiece; and after performing the first cutting step, A second holding step for holding the first surface side of the workpiece with a chuck table so as to expose the second surface; and after performing the second holding step, the second surface of the workpiece is applied to the second surface. A depth of 2 reaching the cutting groove along a second direction intersecting the first direction by cutting the cutting blade; And detecting the position and orientation of the cutting groove from the second surface side based on the alignment groove forming step for forming the alignment groove and a part of the cutting groove exposed at the bottom of the alignment groove. After performing the alignment step and the alignment step, a cutting blade is cut into the second surface based on the position and orientation of the cutting groove detected in the alignment step, and the workpiece is moved along the cutting groove. And a second cutting step for cutting the workpiece. A method for dividing a workpiece is provided.

  In one aspect of the present invention, the thickness of the workpiece may be 25 times or more the blade thickness of the cutting blade. Further, in the thickness direction of the workpiece, it is preferable that the distance that the cutting groove and the alignment groove overlap with each other is 1/2 or more of the thickness of the cutting blade used for forming the cutting groove.

  In the workpiece dividing method according to one aspect of the present invention, the cutting blade is cut into the first surface of the workpiece, and the cutting groove having a depth that does not reach the second surface is along the first direction. Since the cutting blade is cut into the second surface of the workpiece and the alignment groove having a depth reaching the cutting groove is formed along the second direction intersecting the first direction, Based on a part of the cutting groove exposed at the bottom of the alignment groove, the position and orientation of the cutting groove can be detected from the second surface side.

  Therefore, if the cutting blade is cut into the second surface based on the detected position and orientation of the cutting groove, the cutting position on the second surface side can be aligned with the cutting groove with high accuracy. Thus, in the method for dividing a workpiece according to one aspect of the present invention, the workpiece can be divided with high accuracy by matching the cutting position on the second surface side with the cutting groove with high accuracy.

It is a perspective view which shows typically examples, such as a to-be-processed object. FIG. 2A is a partial cross-sectional side view schematically showing the first holding step and the first cutting step of the present embodiment, and FIG. 2B is a workpiece after the first cutting step. FIG. 2C is a plan view schematically showing the first surface side of the workpiece after the first cutting step. FIG. 3A is a partial cross-sectional side view schematically showing the second holding step and the alignment groove forming step of the present embodiment, and FIG. 3B is a work piece after the alignment groove forming step. FIG. 3C is a plan view schematically showing the second surface side of the workpiece after the alignment groove forming step and the alignment step of the present embodiment. It is. FIG. 4A is a partial cross-sectional side view schematically showing the second cutting step of the present embodiment, and FIG. 4B schematically shows the workpiece and the like after the second cutting step. FIG. 4C is a plan view schematically showing the second surface side of the workpiece after the second cutting step.

  An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. The workpiece dividing method according to this embodiment includes a first holding step (see FIG. 2A), a first cutting step (see FIGS. 2A, 2B, and 2C). , Second holding step (see FIG. 3A), alignment groove forming step (see FIG. 3A, FIG. 3B, FIG. 3C), alignment step (see FIG. 3C) And a second cutting step (see FIGS. 4 (A), 4 (B), and 4 (C)).

  In the first holding step, the second surface side of the plate-like workpiece having the first surface and the second surface is held by the chuck table of the cutting device to expose the first surface. In the first cutting step, a cutting blade is cut into the first surface to form a cutting groove having a depth that does not reach the second surface along the first direction of the workpiece.

  In the second holding step, the first surface side of the workpiece is held by the chuck table, and the second surface is exposed. In the alignment groove forming step, a cutting blade is cut into the second surface, and two alignment grooves having a depth reaching the cutting groove along a second direction intersecting the first direction are formed.

  In the alignment step, the position and orientation of the cutting groove are detected from the second surface side based on a part of the cutting groove exposed at the bottom of the alignment groove. In the second cutting step, a cutting blade is cut into the second surface based on the position and orientation of the cutting groove detected in the alignment step, and the workpiece is cut along the cutting groove. Hereinafter, the method for dividing the workpiece according to the present embodiment will be described in detail.

  FIG. 1 is a perspective view schematically showing an example of a workpiece to be divided in the present embodiment. As shown in FIG. 1, the workpiece 11 is a substrate formed in a rectangular shape in plan view using a material such as resin, ceramics, semiconductor, metal, and the like. And a second surface 11b opposite to the first surface 11a. In the present embodiment, the plate-like workpiece 11 formed in a rectangular shape in plan view is used, but the type, size, shape, and the like of the workpiece 11 are not limited.

  In the present embodiment, the workpiece 11 is cut and divided into a plurality of chips. Before carrying out the workpiece dividing method according to the present embodiment, as shown in FIG. 1, the second surface 11b side of the workpiece 11 is temporarily attached with an adhesive tape (not shown). Etc., and fixed to the first surface 21a side of the support member 21. As the support member 21, for example, a substrate larger than the workpiece 11 can be used.

  In the workpiece dividing method according to the present embodiment, first, the first holding step of holding the second surface 11b side of the workpiece 11 with the chuck table of the cutting device and exposing the first surface 11a is performed. carry out. FIG. 2A is a partial cross-sectional side view schematically showing the first holding step and the next first cutting step of the present embodiment.

  The workpiece dividing method according to the present embodiment is performed by, for example, the cutting apparatus 2 shown in FIG. The cutting device 2 includes a chuck table 4 for holding the workpiece 11. The chuck table 4 is connected to a rotation drive source (not shown) including a motor and the like, and rotates around a rotation axis substantially parallel to the vertical direction. A moving mechanism (not shown) is provided below the chuck table 4, and the chuck table 4 is moved in the horizontal direction by the moving mechanism.

  The upper surface of the chuck table 4 is a holding surface 4 a that sucks and holds the support member 21 and the like fixed to the workpiece 11. The holding surface 4 a is connected to a suction source (not shown) through a suction path (not shown) formed inside the chuck table 4. By applying the negative pressure of the suction source to the holding surface 4a, the workpiece 11 is held on the chuck table 4 via the support member 21 and the like.

  An annular first cutting blade 6 for cutting the workpiece 11 is disposed above the chuck table 4. For example, the first cutting blade 6 is formed thinner than the thickness of the workpiece 11. Specifically, the thickness of the workpiece 11 may be 25 times or more the thickness (blade thickness) of the first cutting blade 6.

  The first cutting blade 6 is attached to one end side of a spindle (not shown) serving as a rotating shaft. A rotation drive source (not shown) including a motor or the like is connected to the other end side of the spindle. The spindle is accommodated in a spindle housing (not shown) supported by an elevating mechanism (not shown).

  In the first holding step, the second surface 21b of the support member 21 fixed on the second surface 11b side of the workpiece 11 is brought into contact with the holding surface 4a of the chuck table 4 to apply the negative pressure of the suction source. Let Thereby, the workpiece 11 is held by the chuck table 4 with the first surface 11a exposed upward.

  After the first holding step, the first cutting blade 6 is cut into the first surface 11a, and a cutting groove having a depth that does not reach the second surface 11b along the first direction of the workpiece 11 is formed. The first cutting step to be formed is performed. In the first cutting step, first, the chuck table 4 and the first cutting blade 6 are moved and rotated relative to each other to extend a division line (not shown) set in the first direction of the workpiece 11. The first cutting blade 6 is aligned on the line.

  Next, the first cutting blade 6 is lowered to a predetermined height that does not reach the second surface 11b. Thereafter, as shown in FIG. 2A, the first cutting blade 6 is rotated, and the chuck table 4 is moved in a direction (first direction) parallel to the target division line. As a result, the first cutting blade 6 is cut into the first surface 11a of the workpiece 11, and the cutting groove 11c having a depth that does not reach the second surface 11b is a target division line (first direction). ).

  Here, the cutting depth D1 of the first cutting blade 6 with respect to the workpiece 11 is, for example, not less than ½ of the thickness of the workpiece 11 and less than the thickness of the workpiece 11. Thereby, the curvature of the 1st cutting blade 6 by the load at the time of cutting, etc. is suppressed, and processing precision can be maintained highly. The cutting depth D1 of the first cutting blade 6 may be less than ½ of the thickness of the workpiece 11. In this case, the cutting depth of the subsequent second cutting step is increased.

  After forming the cutting groove 11c along the target division line, the chuck table 4 and the first cutting blade 6 are relatively moved so that the first cutting blade 6 is placed on the extension of the adjacent division line. Match. Then, the first cutting blade 6 is lowered to a predetermined height that does not reach the second surface 11b.

  Thereafter, the first cutting blade 6 is rotated, and the chuck table 4 is moved in a direction (first direction) parallel to the planned division line. Thereby, the cutting groove 11c of the depth which does not reach the 2nd surface 11b can be formed along this division plan line (1st direction). When the above procedure is repeated and the cutting grooves 11c are formed along all the division lines extending in the first direction, the first cutting step ends.

  FIG. 2B is a perspective view schematically showing the workpiece 11 and the like after the first cutting step, and FIG. 2C is a first surface of the workpiece 11 after the first cutting step. It is a top view which shows typically the 11a side. In the first cutting step of the present embodiment, the cutting groove 11c is formed along the planned dividing line extending in the first direction (X-axis direction in FIG. 2C). In addition, another cutting groove may be formed along a planned division line extending in a second direction (the Y-axis direction in FIG. 2C) intersecting the first direction.

  After the first cutting step, a second holding step is performed in which the first surface 11a side of the workpiece 11 is held by the chuck table 4 of the cutting device 2 to expose the second surface 11b. FIG. 3A is a partial cross-sectional side view schematically showing the second holding step and the next alignment groove forming step of the present embodiment.

  In addition, after the first cutting step and before the second holding step, the support member 21 fixed to the second surface 11b side of the workpiece 11 is peeled off and removed, and FIG. As shown, the first surface 11 a side of the workpiece 11 is fixed to the first surface 31 a side of the support member 31. As the support member 31, a substrate similar to the support member 21 can be used. Needless to say, the peeled and removed support member 21 may be fixed to the first surface 11 a side as the support member 31.

  In the second holding step, the second surface 31b of the support member 31 fixed to the first surface 11a side of the workpiece 11 is brought into contact with the holding surface 4a of the chuck table 4 to apply the negative pressure of the suction source. Let Thus, the workpiece 11 is held on the chuck table 4 with the second surface 11b exposed upward.

  After the second holding step, the cutting blade is cut into the second surface 11b, and two alignment grooves having a depth reaching the cutting groove 11c along the second direction intersecting the first direction are formed. An alignment groove forming step to be formed is performed. As shown in FIG. 3A, the cutting device 2 described above further includes a second cutting blade 8 that is thicker than the first cutting blade 6.

  The second cutting blade 8 is mounted on one end side of a spindle (not shown) serving as a rotating shaft. A rotation drive source (not shown) including a motor or the like is connected to the other end side of the spindle. The spindle is accommodated in a spindle housing (not shown) supported by an elevating mechanism (not shown).

  In the alignment groove forming step, first, the chuck table 4 and the second cutting blade 8 are relatively moved and rotated to extend an alignment groove forming line (not shown) set in the workpiece 11. The second cutting blade 8 is aligned with the above. In the present embodiment, alignment groove formation planned lines extending in a second direction intersecting the first direction are set at two locations in the outer edge region of the workpiece 11 corresponding to both ends of each cutting groove 11c. To do.

  Next, the second cutting blade 8 is lowered to a predetermined height that does not reach the first surface 11a. Thereafter, as shown in FIG. 3A, the second cutting blade 8 is rotated, and the chuck table 4 is moved in a direction (second direction) parallel to the target alignment groove formation planned line. Thereby, the 2nd cutting blade 8 is cut into the 2nd surface 11b of the to-be-processed object 11, and the alignment groove | channel 11d along the target alignment groove formation plan line (2nd direction) can be formed.

  Here, the cutting depth D2 of the second cutting blade 8 with respect to the workpiece 11 is set to such a depth that a part of the cutting groove 11c is exposed from the bottom of the alignment groove 11d to be formed. That is, in the thickness direction of the workpiece 11, a part of the cutting groove 11 c and a part of the alignment groove 11 d overlap each other.

  A distance D3 in which the cutting groove 11c and the alignment groove 11d overlap in the thickness direction of the workpiece 11 is set to ½ or more of the thickness of the first cutting blade 6 used for forming the cutting groove 11c. It is desirable. As a result, the tip portion of the first cutting blade 6 is worn in a curved shape, and the shape (curved surface) of the tip portion becomes asymmetric with respect to the center of the thickness of the first cutting blade 6 (that is, the first cutting blade). Even when 6 is unevenly worn), the cutting groove 11c is exposed from the bottom of the alignment groove 11d to a portion not affected by the shape of the tip portion, so that the position of the cutting groove 11c does not change. It will end. Therefore, the position and direction of the cutting groove 11c can be detected with high accuracy.

  After the alignment groove 11d is formed along the target alignment groove formation planned line, the chuck table 4 and the second cutting blade 8 are moved relative to each other on an extension line of another alignment groove formation planned line. The second cutting blade 8 is aligned with the above. Then, the second cutting blade 8 is lowered to a predetermined height that does not reach the first surface 11a.

  Thereafter, the second cutting blade 8 is rotated to move the chuck table 4 in a direction (second direction) parallel to the alignment groove formation planned line. Thereby, the alignment groove 11d along the alignment groove formation planned line (second direction) can be formed. When the two alignment grooves 11d that are separated from each other are formed, the alignment groove forming step ends.

  In this embodiment, the alignment groove 11d is formed along the alignment groove formation planned line set in advance on the workpiece 11, but the alignment groove is not set without setting the alignment groove formation planned line. 11d may be formed. The alignment groove 11d does not need to be orthogonal to the cutting groove 11c, and may be formed at least so as to cross the cutting groove 11c and expose the cutting groove 11c. Therefore, for example, the second direction for forming the cutting groove 11c may be roughly determined with reference to the end (side) of the workpiece 11 or the like.

  FIG. 3B is a perspective view schematically showing the workpiece 11 after the alignment groove forming step, and FIG. 3C is a second view of the workpiece 11 after the alignment groove forming step. It is a top view which shows typically the surface 11b side of this, and the next alignment step. In the alignment groove forming step of the present embodiment, two alignment grooves 11d that are separated from each other are formed, but three or more alignment grooves 11d that are separated from each other may be formed.

  Further, in the first cutting step, when the cutting groove is formed along the division planned line extending in the second direction intersecting with the first direction, 2 corresponding to the cutting groove is formed in the alignment groove forming step. Two (or three or more) alignment grooves are formed together. That is, in this case, in addition to two (or three or more) alignment grooves 11d along the second direction (Y-axis direction in FIG. 3C), the first direction (FIG. 3C 2) (or 3 or more) alignment grooves along the X-axis direction) are further formed.

  After the alignment groove forming step, an alignment step for detecting the position and orientation of the cutting groove 11c from the second surface 11b side is performed based on a part of the cutting groove 11c exposed at the bottom of the alignment groove 11d. . As shown in FIG. 3C, a part of the cutting groove 11c is exposed at the bottom of the alignment groove 11d.

  Therefore, the position and direction of the cutting groove 11c can be detected from the second surface 11b side by capturing a part of the exposed cutting groove 11c with a camera or the like and acquiring coordinates. In the present embodiment, coordinates are acquired at two locations corresponding to the two alignment grooves 11d with respect to one cutting groove 11c. As described above, by acquiring the coordinates at two or more locations away from the single cutting groove 11c, the position and orientation of the cutting groove 11c can be detected with high accuracy.

  After the alignment step, the first cutting blade 6 is cut into the second surface 11b based on the position and orientation of the cutting groove 11c detected in the alignment step, and the workpiece 11 is cut along the cutting groove 11c. A second cutting step is performed. FIG. 4A is a partial cross-sectional side view schematically showing the second cutting step of the present embodiment.

  In the second cutting step, first, the chuck table 4 and the first cutting blade 6 are relatively moved and rotated to align the first cutting blade 6 on the extended line of the cutting groove 11c detected in the alignment step. Next, the first cutting blade 6 is lowered to a predetermined height that does not reach the first surface 11a.

  Thereafter, as shown in FIG. 4A, the first cutting blade 6 is rotated, and the chuck table 4 is moved in a direction (first direction) parallel to the target cutting groove 11c. Thereby, the 1st cutting blade 6 is cut into the 2nd surface 11b of the workpiece 11, the kerf (cutting edge) 11e is formed, and the workpiece 11 can be cut | disconnected along the target cutting groove 11c.

  Here, the cutting depth D4 of the first cutting blade 6 with respect to the workpiece 11 is determined according to the cutting depth D1 of the first cutting blade 6 in the second cutting step. Specifically, the cutting depth D4 is set so that the sum of the cutting depth D1 and the cutting depth D4 is equal to or greater than the thickness of the workpiece 11. Thereby, the workpiece 11 can be cut through the second surface 11b and the bottom of the cutting groove 11c.

  In this case as well, the first cutting is performed from the bottom of the cutting groove 11c to a position deeper than 1/2 of the thickness of the first cutting blade 6 in order to prevent a reduction in processing accuracy due to uneven wear of the first cutting blade 6. It is desirable to cut the blade 6. That is, the cutting depth D4 may be set so that the sum of the cutting depth D1 and the cutting depth D4 is equal to or greater than the sum of the thickness of the workpiece 11 and 1/2 of the thickness of the cutting blade 6. desirable.

  After forming the cutting groove 11c along the target cutting groove 11c, the chuck table 4 and the first cutting blade 6 are relatively moved and rotated, and the first cutting blade is placed on the extension line of the adjacent cutting groove 11c. Match 6. Then, the first cutting blade 6 is lowered to a predetermined height that does not reach the first surface 11a.

  Thereafter, the first cutting blade 6 is rotated to move the chuck table 4 in a direction (first direction) parallel to the cutting groove 11c. Thereby, the workpiece 11 can be cut along the cutting groove 11c. When the above procedure is repeated and the workpiece 11 is cut along all the cutting grooves 11c, the second cutting step ends.

  FIG. 4B is a perspective view schematically showing the workpiece 11 and the like after the second cutting step, and FIG. 4C is a second surface of the workpiece 11 after the second cutting step. It is a top view which shows the side typically. In the first cutting step, when the cutting groove is formed along the division line extending in the second direction intersecting the first direction, the cutting groove is formed along the cutting groove in the second cutting step. The workpiece 11 is further cut. That is, in this case, the workpiece 11 is cut along the cutting groove 11c extending in the first direction (X-axis direction in FIG. 4C), and in the second direction (in FIG. 4C). The workpiece 11 is cut along a cutting groove extending in the (Y-axis direction).

  As described above, in the workpiece dividing method according to the present embodiment, the first cutting blade 6 is cut into the first surface 11a of the workpiece 11, and the depth does not reach the second surface 11b. After the cutting groove 11c is formed along the first direction, the second cutting blade 8 is cut into the second surface 11b of the workpiece 11, and the alignment groove 11d having a depth reaching the cutting groove 11c is formed. Since the second groove 11c is formed along the second direction intersecting with the first direction, the position and orientation of the cutting groove 11c is set on the second surface 11b side based on a part of the cutting groove 11c exposed at the bottom of the alignment groove 11d. Can be detected from.

  Therefore, if the first cutting blade 6 is cut into the second surface 11b based on the detected position and orientation of the cutting groove 11c, the cutting position on the second surface 11b side is adjusted to the cutting groove 11c with high accuracy. be able to. Thus, in the method for dividing the workpiece according to the present embodiment, the workpiece 11 can be divided with high accuracy by matching the cutting position on the second surface 11b side with the cutting groove 11c with high accuracy.

  In addition, this invention is not limited to description of the said embodiment, A various change can be implemented. For example, in the above embodiment, the alignment groove 11d is formed using the second cutting blade 8 in the alignment groove forming step, but the present invention is not limited to this aspect. If the part of the cutting groove 11c exposed at the bottom of the alignment groove 11d can be appropriately detected from the second surface 11b side, the first cutting blade 6 may be used to form the alignment groove 11d. .

  In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented without departing from the scope of the object of the present invention.

11 Workpiece 11a First surface 11b Second surface 11c Cutting groove 11d Alignment groove 11e Calf (cut)
DESCRIPTION OF SYMBOLS 21 Support member 21a 1st surface 21b 2nd surface 31 Support member 31a 1st surface 31b 2nd surface 2 Cutting device 4 Chuck table 4a Holding surface 6 1st cutting blade 8 2nd cutting blade

Claims (3)

A dividing method of dividing a plate-like workpiece having a first surface and a second surface opposite to the first surface with a cutting blade,
A first holding step of holding the second surface side of the workpiece with a chuck table so as to expose the first surface;
After performing the first holding step, a cutting blade is cut into the first surface of the workpiece, and the cutting groove has a depth that does not reach the second surface along the first direction of the workpiece. Forming a first cutting step;
A second holding step of holding the first surface side of the workpiece with a chuck table so as to expose the second surface after performing the first cutting step;
After performing the second holding step, a cutting blade is cut into the second surface of the workpiece, and the depth reaching the cutting groove along a second direction intersecting the first direction is increased. An alignment groove forming step for forming two alignment grooves;
An alignment step of detecting the position and orientation of the cutting groove from the second surface side based on a part of the cutting groove exposed at the bottom of the alignment groove;
After performing the alignment step, a cutting blade is cut into the second surface based on the position and orientation of the cutting groove detected in the alignment step, and the workpiece is cut along the cutting groove. A method for dividing a workpiece, comprising: 2 cutting steps.   The method of dividing a workpiece according to claim 1, wherein the thickness of the workpiece is 25 times or more the blade thickness of the cutting blade.   The distance in which the cutting groove and the alignment groove overlap in the thickness direction of the workpiece is 1/2 or more of the thickness of a cutting blade used for forming the cutting groove. A method for dividing a workpiece according to claim 1.