JP2012151225A - Method for measuring cut groove - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the problem in which an image of a measurement groove being formed in a workpiece to detect the amount of displacement of a cutting blade cannot be sometimes taken by imaging means.SOLUTION: A range of imaging of a measurement groove G3 by second imaging means 46B is set as a location where an arbitrary street 2 elongated in an indexing direction is a reference line L and which is shifted by a distance a little longer than the integral multiple of an interval between the streets 2 in a working direction from the reference line L. Thus, an image of the measurement groove G3 can be taken as in such a manner that the image to be taken is obtained as a similar image when the measurement groove G3 is formed on any street 2.

Description

  In the present invention, for a workpiece such as a semiconductor wafer, a first cutting groove is formed by a first cutting blade, and then a second cutting groove is formed in the first cutting groove by a second cutting blade. Thus, the present invention relates to a cutting groove measuring method for measuring the positions of a first cutting groove and a second cutting groove when forming a cutting groove on one street in two stages.

  In the semiconductor device manufacturing process, a large number of electronic circuits such as IC and LSI are formed on the surface of a substantially disk-shaped workpiece such as a semiconductor wafer, and then the back surface of the workpiece is ground to a predetermined thickness. After the processing, the device region in which the electronic circuit is formed is cut by a cutting blade along a planned division line called street to divide the work, and a large number of devices are obtained from one work.

  In this type of workpiece, for example, when it is relatively thick or has a heterogeneous layer partially formed such as TEG (Test Element Group), it is difficult to cut by one cutting. There are cases. In such a case, two types of cutting blades having different thicknesses are used, and the first cutting groove is formed to the middle of the workpiece thickness with the thicker first cutting blade first for one street. Then, a technique is employed in which the workpiece is cut by forming a second cutting groove by cutting a thin second cutting blade along the bottom of the first cutting groove.

  In a cutting device that cuts a workpiece with a cutting blade, in order to accurately form a cutting groove along the street, the surface of the workpiece is detected by imaging the workpiece surface with an imaging means, and the detected street position is detected. Alignment is performed so that the cutting lines of the cutting blades coincide with each other. The imaging means has a cutting reference line that matches the cutting line of the cutting blade, and by matching this cutting reference line to the street, the cutting line of the cutting blade matches the street so that alignment is achieved. It has become.

  However, in the case of a cutting blade, the position of the cutting blade with respect to the cutting reference line of the image pickup means may be displaced due to, for example, the reason that the spindle that supports the cutting blade generates heat and thermally expands due to operation. In this case, even if the cutting reference line of the imaging means is aligned with the street, the cutting blade is displaced from the street, and the cutting groove is not accurately formed along the street. Therefore, the cutting groove is periodically imaged by the imaging means, the displacement between the cutting reference line of the imaging means and the cutting groove is measured to detect the amount of displacement of the cutting blade, and the position of the cutting blade is determined according to the amount of displacement. It has been done to correct.

  However, when the workpiece is cut by forming the first cutting groove and the second cutting groove on the street as described above, the second cutting groove is formed in the first cutting groove. It is difficult to pick up an image with the image pickup means, and thus it is difficult to detect the displacement amount of the second cutting blade. Therefore, before forming the first cutting groove, a measurement groove is formed in the direction along the street by the second cutting blade on the outer periphery of the workpiece, and the displacement amount of the second cutting blade is obtained by imaging the measurement groove. A measurement method that enables detection of the above has been proposed (Patent Document 1).

Japanese Patent No. 4377702

  Thus, when the measurement groove formed on the outer peripheral portion of the workpiece as described above is imaged by the imaging means, as shown in FIG. 9, the outer peripheral edge 1a on the inner peripheral side from the outer peripheral edge 1a of the workpiece 1 is A method is used in which the measurement groove G3 formed in the street 2 is imaged with the location centered on the concentric circle line 1b as the imaging range. As described above, in the method of setting the imaging range based on the outer peripheral edge 1a as described above, the image to be captured differs depending on which street 2 the measurement groove G3 is formed on. That is, the captured image is a part of the device region 3 between the street 2 and the street 2, but the position and shape of the street 2 and the device region 3 within the angle of view are different for each measurement groove G3.

  If the images captured in this way are different, the measurement groove may not be clearly captured depending on the imaging range. For this reason, it is necessary to change settings for imaging such as the amount of light, and with certain settings, it may not be possible to capture the imaging range of all locations so that the measurement grooves are clearly imaged.

  The present invention has been made in view of the above circumstances, and its main technical problem is that the measurement groove formed in the workpiece in order to detect the amount of displacement of the cutting blade may not be imaged by the imaging means. An object of the present invention is to provide a cutting groove measuring method capable of avoiding the problem of being present.

  The cutting groove measuring method of the present invention includes a chuck table for holding a workpiece, a first cutting means having a first cutting blade for cutting the workpiece held on the chuck table, and the first cutting means. A second cutting means having a second cutting blade that is narrower than the first cutting blade for further cutting the area cut by the cutting means; an imaging means for detecting a street that is an area to be cut; And detecting a street of the workpiece held on the chuck table by the imaging means, and forming a first cutting groove having a predetermined depth on the street of the workpiece by the first cutting means. And the step of forming the second cutting groove along the first cutting groove by the second cutting means, the first formed on the workpiece. A measuring method for measuring the position of a cutting groove and the second cutting groove, wherein when measuring the position of the first cutting groove, the first cutting groove formed on a workpiece is measured by the imaging means. And measuring the positional relationship between the street and the first cutting groove, and when measuring the position of the second cutting groove, before forming the first cutting groove, The measurement groove is formed by the second cutting means, the imaging means is positioned so as to image a predetermined location of the measurement groove, the positional relationship between the street and the measurement groove is measured, and the predetermined location of the measurement groove Is characterized in that an arbitrary street extending in the indexing direction is used as a reference line, and a place is moved from the reference line in the machining direction by a plus alpha distance to an integral multiple of the street interval.

  According to the present invention, the imaging range of the measurement groove by the imaging means is set to a place where an arbitrary street extending in the indexing direction is set as a reference line, and a plus alpha distance is moved from the reference line to the machining direction by an integral multiple of the street interval. By doing so, the captured image is the same regardless of the street where the measurement groove is formed. Here, the same image means a state in which, even if different streets are captured, the position, shape, color, and the like of the street and the surrounding portion of the street are reflected in the same angle of view. For this reason, it is possible to image any measurement groove formed in any street in a state where the setting for imaging such as the amount of light is constant.

The workpiece in the present invention is not particularly limited. For example, a semiconductor wafer made of silicon, gallium arsenide (GaAs), silicon carbide (SiC), or the like, or a DAF (Die Attach Film) provided on the back surface of the wafer for chip mounting. Adhesive members, semiconductor product packages, ceramics, glass, sapphire (Al ₂ O ₃ ) inorganic material substrates, various electronic components such as LCD drivers for controlling and driving liquid crystal display devices, and micron-order processing position accuracy is required Various processing materials are mentioned.

  ADVANTAGE OF THE INVENTION According to this invention, the measuring method of the cutting groove which can avoid the problem that the measuring groove formed in a workpiece | work in order to detect the displacement amount of a cutting blade may not be imaged with an imaging means is provided. There is an effect such as.

It is a perspective view of the work unit formed by supporting the work concerning one embodiment of the present invention on the annular frame via the adhesive tape. It is a perspective view of the cutting device of one embodiment. It is a front view which shows the 1st Y-axis moving means with which the same cutting apparatus is equipped, the 2nd Y-axis moving means, and the 1st cutting means and 2nd cutting means which were provided in these Y-axis moving means. It is sectional drawing of the cutting groove formed in a workpiece | work by the cutting device, (a) The 1st cutting groove formed by the 1st cutting blade, (b) The 1st cutting groove by the 2nd cutting blade The state which formed the 2nd cutting groove in is shown. It is sectional drawing which shows an example of the form which cuts a workpiece | work with the 1st cutting blade and 2nd cutting blade of the cutting device. In detecting the amount of displacement of the cutting blade, it is an image obtained by imaging the cutting groove by the imaging means, (a) an image showing the first cutting groove formed by the first cutting blade, and (b) the second cutting. It is an image which shows the 2nd cutting groove formed with the braid | blade. It is a figure which shows the measuring method which concerns on one Embodiment, Comprising: The imaging range by the imaging means of the measurement groove | channel formed in the street with the 2nd cutting blade is shown. It is a figure which shows the imaging range shown in FIG. 7 separately. It is a figure which shows the measuring method of the conventional measurement groove | channel, Comprising: The imaging range by the imaging means of the measurement groove | channel formed in the street with the 2nd cutting blade is shown. It is a figure which shows the imaging range shown in FIG. 9 separately.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(1) Workpiece First, a work 1 according to an embodiment shown in FIG. 1 will be described. The workpiece 1 is a disk-shaped semiconductor wafer or the like, and a large number of rectangular device regions 3 partitioned by a plurality of streets 2 orthogonal to each other are formed on the surface. On the surface of each device region 3, an electronic circuit 9 (see FIG. 5) such as an IC or LSI is formed. A linear notch (orientation flat) 4 indicating the crystal orientation of the semiconductor is formed at a predetermined location on the peripheral surface of the workpiece 1.

  The workpiece 1 is cut along the street 2 by the cutting apparatus 10 shown in FIG. 2 and divided into a large number of device regions 3, that is, devices. As shown in FIG. 1, the workpiece 1 is supplied to the cutting device 10 in a state of being supported integrally and concentrically via an adhesive tape 6 in an opening 5 a inside the annular frame 5. The adhesive tape 6 has an adhesive surface on one side, and the frame 5 and the back surface of the work 1 are attached to the adhesive surface. The frame 5 has rigidity made of a plate material such as metal, and the work 1 is conveyed by supporting the frame 5. Hereinafter, the entire work 1 supported by the frame 5 via the adhesive tape 6 is referred to as a work unit 7.

(2) Cutting Device Next, the cutting device 10 shown in FIG. 2 will be described. The cutting apparatus 10 is a biaxially opposed type in which a pair of cutting means (first cutting means 40A and second cutting means 40B) are arranged to face each other, and the work 1 of the work unit 7 held by the chuck table 32 is used. Are cut by the cutting means 40A and 40B. Operations relating to the cutting are controlled by the control means 70.

(2-1) Configuration of Cutting Device Reference numeral 11 in FIG. 2 is a base, and an X-axis moving means 20 that supports the chuck table 32 so as to be movable in the X direction is provided on the upper surface of the base 11. Yes. The X-axis moving means 20 includes a pair of X-axis linear guides 21 fixed on the base 11 and extending in the X direction, an X-axis movable base portion 22 slidably incorporated in these X-axis linear guides 21, A ball screw 23 that is rotatably disposed between the X-axis linear guides 21 and that is screwed to and coupled to the X-axis movable base portion 22 extends in the X direction, and a motor 24 that rotates the ball screw 23. Yes. According to this X-axis moving means 20, when the motor 24 is operated, the ball screw 23 rotates, and the X-axis movable base portion 22 moves in the direction corresponding to the rotation direction of the ball screw 23 (X1 direction or X2 direction). 21 is moved.

  A holding means 30 is provided on the upper surface of the X-axis movable base portion 22. The holding means 30 includes a cylindrical table base 31 fixed to the X-axis movable base portion 22, and a disk-shaped chuck table 32 that is rotatably supported on the table base 31. The chuck table 32 is of a generally known vacuum chuck type that holds and holds the workpiece 1 placed on the holding surface 32a on the horizontal upper surface by a negative pressure effect generated by sucking air. The holding surface 32a has a diameter equivalent to that of the workpiece 1, and the workpiece 1 is placed concentrically on the holding surface 32a via the adhesive tape 6 and is sucked and held.

  The chuck table 32 is provided with a plurality of clamps 35 for holding the frame 5 of the work unit 7. The chuck table 32 is rotated in one direction or both directions by a rotation drive mechanism (not shown) provided in the table base 31. The holding means 30 is reciprocated between the loading / unloading position on the near side (X1 side) in the X direction and the processing position on the far side (X2 side) by the X-axis moving means 20.

  In FIG. 2, a gate-type column 12 straddling the processing position is fixed to the X2 side on the base 11. The portal column 12 has a pair of leg portions 12a erected side by side in the Y direction on both sides of the machining position, and a beam portion 12b horizontally spanned between the upper end portions of the leg portions 12a. Yes. Then, on the Y1 side of the front surface (X1 side surface) of the beam portion 12b, the first cutting means 40A is in the Y direction and the Z direction via the first Y axis moving means 50A and the first Z axis moving means 60A. The second cutting means 40B is provided in the Y direction and the Z direction via the second Y axis moving means 50B and the second Z axis moving means 60B on the Y2 side of the front surface of the beam portion 12b. It is provided to be movable.

  The first Y-axis moving unit 50A and the second Y-axis moving unit 50B have the same configuration, and a pair of upper and lower Y-axis linear guides 51 fixed to the beam portion 12b are used as a common component. The Y-axis linear guide 51, the Y-axis movable base 52 slidably incorporated in the Y-axis linear guide 51, and a ball screw extending in the Y direction rotatably disposed between the Y-axis linear guides 51. 53 and a motor 54 for rotating the ball screw 53 (in FIG. 2, the second Y-axis moving means 50B side is not shown, see FIG. 3). One ball screw 53 is provided on the first Y-axis moving means 50A side and one on the second Y-axis moving means 50B side. One ball screw 53 is the first Y-axis moving means. The other ball screw 53 is screwed and connected to the Y-axis movable base portion 52 of the second Y-axis moving means 50B.

  The first Z-axis moving unit 60A and the second Z-axis moving unit 60B are provided on the front surface of the Y-axis movable base 52 in the first Y-axis moving unit 50A and the second Y-axis moving unit 50B, respectively. Yes. The first Z-axis moving unit 60A and the second Z-axis moving unit 60B have the same configuration, and are a pair of Z-axis linear guides 61 that are fixed to the Y-axis movable base portion 52 and are separated in the Y direction, and these A Z-axis movable base 62 that is slidably incorporated in the Z-axis linear guide 61 and a Z-axis that is rotatably disposed between the Z-axis linear guide 61 and screwed to the Z-axis movable base 62. The ball screw 63 extends in the direction (vertical direction), and the motor 64 rotates the ball screw 63.

  The first cutting means 40A is fixed to the lower end of the Z-axis movable base 62 of the first Z-axis moving means 60A, and the lower end of the Z-axis movable base 62 of the second Z-axis moving means 60B. In addition, the second cutting means 40B is fixed. Each of the first cutting means 40A and the second cutting means 40B has a rectangular parallelepiped spindle housing 41. As shown in FIG. 3, a spindle shaft 42 and a motor 43 that rotationally drives the spindle shaft 42 are accommodated in the spindle housing 41, and the first end of the spindle shaft 42 protruding from the front end opening of the spindle housing 41 The disc-shaped first cutting blade 44A is attached to the first cutting means 40A, and the disc-shaped second cutting blade 44B is attached to the second cutting means 40B.

  The cutting blades 44A and 44B have different thicknesses, and the thickness of the first cutting blade 44A is larger than that of the second cutting blade 44B. The thickness of the first cutting blade 44A is, for example, about 40 μm, and the thickness of the second cutting blade 44B is, for example, about 20 μm.

  In the cutting means 40A and 40B, the spindle housing 41 is in the state in which the spindle shaft 42 is parallel to the Y direction and coaxial with each other, and the tips to which the cutting blades 44A and 44B are attached face each other. And fixed to the lower end of each Z-axis movable base 62 in the second Z-axis moving means 60B. As shown in FIG. 2, a blade cover 45 that has a cutting water supply nozzle that supplies cutting water to the workpiece 1 and suppresses the scattering of the cutting water splashed by the rotating workpiece 1 is provided at the tip of the spindle housing 41. It is attached.

  According to the first Y-axis moving means 50A and the second Y-axis moving means 50B, when the respective motors 54 are operated, the ball screw 53 rotates in either the forward or reverse direction, and the Y-axis movable base portion 52 becomes the ball screw. It moves along the Y-axis linear guide 51 in a direction (Y1 direction or Y2 direction) according to the rotation direction of 53. Accordingly, the first cutting means 40A and the second cutting means 40B move along the Y direction so as to approach or separate from each other.

  Also, according to the first Z-axis moving means 60A and the second Z-axis moving means 60B, when each motor 64 is operated, the ball screw 63 rotates in either the forward or reverse direction, and the Z-axis movable base 62 is The ball screw 53 moves up and down along the Z-axis linear guide 61 in a direction (upward: Z1 direction or downward: Z2 direction) according to the rotation direction of the ball screw 53. As a result, the first cutting means 40A and the second cutting means 40B move up and down along the Z direction, respectively.

  As shown in FIG. 2, in each of the cutting means 40 </ b> A and 40 </ b> B, the surface of the work 1 held by the chuck table 32 at a position close to the blade cover 45 on the front surface (X1 side surface) of the spindle housing 41. The first image pickup means 46A and the second image pickup means 46B for picking up images are respectively fixed. The images picked up by the image pickup means 46A and 46B are supplied to the control means 70, and the control means 70 performs the alignment based on the images picked up by the image pickup means 46A and 46B.

(2-2) Cutting by Cutting Device Next, the operation of the cutting device 10 controlled by the control means 70 will be described.
First, the X-axis movable base portion 22 of the X-axis moving means 20 moves in the X1 direction in FIG. 2, the holding means 30 is positioned at the carry-in / out position, and the chuck table 32 is operated in vacuum. Then, the work unit 7 having the work 1 placed on the upper side and the adhesive tape 6 placed on the lower side is transported on the holding means 30 by the operator, and the work 1 is concentrically arranged on the chuck table 32 via the adhesive tape 6. Placed on. Then, the work 1 is attracted and held on the holding surface 32 a of the chuck table 32 via the adhesive tape 6. Further, the frame 5 is held by the clamp 35, and the work unit 7 is held by the holding means 30. The workpiece 1 is held on the chuck table 32 so that the street 2 extending in one direction is parallel to the X direction of the machining direction.

  Next, the X-axis movable base portion 22 moves in the X2 direction in FIG. 2, and the workpiece 1 is transported to the machining position together with the holding means 30. At this processing position, alignment is performed so that the cutting lines of the cutting blades 44A and 44B coincide with the center of the street in the width direction.

  For alignment, first, the angular deviation in the circumferential direction of the workpiece 1 with respect to the chuck table 32 is examined. The angular deviation of the workpiece 1 is determined by positioning the workpiece 1 immediately below one of the imaging means 46A (46B) of the cutting means 40A and 40B, imaging the surface of the workpiece 1, and setting a predetermined interval in the X direction of the workpiece 1. The device region 3 in the two alignment spots set in the above is detected. Then, an angular deviation of the workpiece 1 is detected based on the xy coordinates of the reference points of a predetermined pattern formed in the device region 3 in the two device regions 3. If there is an angle shift, the chuck table 32 is rotated to match the y coordinates of the reference points of the two predetermined patterns. Here, the xy coordinates of the reference points of the two predetermined patterns whose y coordinates coincide with each other are stored as alignment reference coordinates.

  Next, the surface of the workpiece 1 is imaged by the first imaging unit 46A on the first cutting unit 40A side and the second imaging unit 46B on the second cutting unit 40B side, and the position of the street 2 is detected. The alignment is completed as described above. Subsequently, the streets 2 along the X direction are sequentially cut by the cutting means 40A and 40B according to the alignment.

  The cutting of the street 2 is performed by machining feed that cuts the cutting edge at the lower end of each of the cutting blades 44A and 44B into the street 2 while moving the workpiece 1 in the X direction by moving the X-axis movable base portion 22 in the X direction. Made. The selection of the street 2 to be cut is made by index feed that moves the cutting means 40A and 40B in the Y direction by the interval of the street 2 that is grasped in advance.

  In the present embodiment, the first cutting groove G1 is halfway through the thickness of the workpiece 1 as shown in FIG. Then, the second cutting blade 44B having a smaller thickness is cut along the bottom of the first cutting groove G1 until it reaches the adhesive tape 6 as shown in FIG. The workpiece 1 is cut by forming the cutting groove G2. Thus, in order to form the cutting groove in two stages on one street 2, for example, as shown in FIG. 5, the first cutting blade 44A and the second cutting blade 44B are in the indexing direction. Efficiently performing by arranging a plurality of streets 2 at intervals in the Y direction, and alternately performing the cutting process on the streets 2 and the index feed to the first cutting blade 44A side (Y1 side). Can do.

  After the first cutting groove G1 and the second cutting groove G2 are formed in all the streets 2 extending in the X direction, that is, in the machining direction, and the cutting is finished, the chuck table 32 is rotated by 90 ° to be parallel to the indexing direction. The street 2 is made parallel to the X direction, the first cutting groove G1 is formed on the entire street 2 by the first cutting blade 44A in the same manner as described above, and the second cutting blade 44B is formed in the first cutting groove G1. Thus, the second cutting groove G2 is formed and the street 2 is cut.

  As described above, all the streets 2 are cut, and the work 1 is divided into each device region 3, that is, a device. After the workpiece 1 is divided, the holding means 30 returns to the loading / unloading position, the vacuum operation of the chuck table 32 is stopped, and the holding of the frame 5 by the clamp 35 is released. Thereafter, the work unit 7 is picked up from the chuck table 32 by the operator, and the work 1 is moved to the next process (for example, a cleaning process).

  The above is one processing cycle of the cutting apparatus 10, and this cycle is performed continuously, and a large number of workpieces 1 are divided into devices. By the way, while cutting a plurality of workpieces 1 continuously, the positions of the cutting blades 44A and 44B are changed to the respective imaging means 46A for the reason that the cutting means 40A and 40B generate heat and thermally expand, for example. , 46B may deviate from the cutting reference line. Therefore, the displacement amounts of the cutting blades 44A and 44B are periodically detected to correct the positions of the cutting blades 44A and 44B.

(2-3) Position correction of the cutting blade In order to detect the amount of displacement of the first cutting blade 44A, after forming the first cutting groove G1 to be detected formed by the first cutting blade 44A, the indexing direction The predetermined position of the first cutting groove G1 to be detected is imaged by the first imaging means 46A while maintaining the position. The image pickup signal is supplied to the control means 70, and the control means 70 forms an image based on the image pickup signal. FIG. 6A shows an example of the image at this time. According to the image shown in FIG. 6, the first cutting groove G1 extends from the cutting reference line 46a of the first imaging means 46A in the Y1 direction of the indexing direction. Therefore, the displacement amount of the first cutting blade 44A from the cutting reference line 46a is detected as the distance S1 in the Y1 direction.

  Next, in order to detect the amount of displacement of the second cutting blade 44B, as shown in FIG. 7, the second cutting blade 44B is placed on an arbitrary street 2 where the first cutting groove G1 is not yet formed. A measurement groove G3 having a predetermined distance is formed. As described above, when the measurement groove G3 is formed on the street 2 by the second cutting means 40B before the first cutting groove G1 is formed, the second imaging means 46B is positioned so as to image a predetermined portion of the measurement groove G3. Then, the predetermined portion is imaged.

  F1 and F2 in FIG. 7 indicate an imaging range corresponding to the predetermined location in which the measurement groove G3 is imaged by the second imaging means 46B. In FIG. 7, two lower imaging ranges F1 and two upper imaging ranges F2 arranged in the Y direction are shown, but these imaging ranges F1 and F2 are in the indexing direction (Y direction in FIG. 7). An arbitrary street 2 that extends is defined as a reference line L, and is moved from the reference line L in the machining direction (X direction in FIG. 7) by a distance of plus alpha to an integral multiple of the interval of the streets 2.

  In FIG. 7, the lower two imaging ranges F1 are at a position twice the distance of the street 2 + distance α in the processing direction from the reference line L, and the upper two imaging ranges F2 are in the processing direction from the reference line L. It is at a position of 3 times the interval of street 2 + distance α. The reference line L is created by the control means 70. For example, the reference line L can be created based on the alignment reference coordinates stored when the angle deviation of the chuck table 32 is examined. In FIG. 7, a plurality (four) of the measurement grooves G3 are shown, but these measurement grooves G3 are formed one by one when periodically detecting the amount of displacement of the second cutting blade 44B.

  When the measurement groove G3 is imaged by the second imaging unit 46B, the imaging signal is supplied to the control unit 70, and the control unit 70 forms an image based on the imaging signal. FIG. 6B shows an example of the image at this time. According to the image shown in FIG. 6, the measurement groove G3 is a distance S2 in the Y2 direction of the indexing direction from the cutting reference line 46b of the second imaging means 46B. Therefore, the displacement amount of the second cutting blade 44B from the cutting reference line L is detected as the distance S2 in the Y2 direction.

  When the displacement amounts of the first cutting blade 44A and the second cutting blade 44B are detected as described above, the positions of the first cutting blade 44A and the second cutting blade 44B are determined according to the detected displacement amount. Then, correction is made so as to match the cutting reference lines 46a and 46b of the imaging means 46A and 46B, respectively. The position of the first cutting blade 44A is corrected by moving the first cutting means 40A by the amount of displacement in the direction opposite to the displacement direction by the first Y-axis moving means 50A. The position of the second cutting blade 44B is corrected by moving the second cutting means 40B by the amount of displacement in the direction opposite to the displacement direction by the second Y-axis moving means 50B. By correcting the displacement amount of each of the cutting blades 44A and 44B in this way, the cutting line of each of the cutting blades 44A and 44B coincides with the center of the street 2, and the street 2 is normally cut.

  According to the method of measuring the measurement groove G3 formed in order to detect the displacement amount of the second cutting blade 44B according to the present embodiment, the imaging ranges F1 and F2 of the measurement groove G3 by the second imaging means 46B are set. As shown in FIG. 8, the measurement is performed by setting an arbitrary street 2 extending in the indexing direction as a reference line L and moving it from the reference line L by an integral multiple of the interval between the streets 2 in the processing direction to a plus alpha distance. Regardless of which street 2 the groove G3 is formed on, the captured image is the same. Here, the same image means that even if different streets 2 are imaged, the position, shape, color, etc. of street 2 and the surrounding area (for example, electronic circuit 9) in the angle of view are the same. Say the state of reflection. For this reason, it is possible to image any measurement groove G3 formed in any street 2 in a state where the setting for imaging such as the amount of light is constant. Therefore, it is possible to avoid the problem that the measurement groove G3 formed in the workpiece 1 in order to detect the displacement amount of the second cutting blade 44B cannot be imaged by the second imaging means 46B.

  In the above-described embodiment, an arbitrary street 2 extending in the indexing direction is set as the reference line L, and an image of the measurement groove G3 is captured at a location moved from the reference line L by an integral multiple of the interval between the streets 2 in the processing direction. Although it is a range, the imaging range may be an arbitrary location that is a fixed distance away from the reference line L in the processing direction regardless of the street 2. Furthermore, without setting the reference line L, the alignment reference coordinate may be set as a reference position, and an arbitrary position away from the reference position in the processing direction by a certain distance may be set as the imaging range of the measurement groove G3. In either case, the image in the imaging range is the same even if the street 2 is different, and the effect that the measurement groove G3 can be imaged remains unchanged.

  DESCRIPTION OF SYMBOLS 1 ... Work, 2 ... Street, 10 ... Cutting apparatus, 32 ... Chuck table, 40A ... 1st cutting means, 40B ... 2nd cutting means, 44A ... 1st cutting blade, 44B ... 2nd cutting blade, 46A ... first imaging means, 46B ... second imaging means, G1 ... first cutting groove, G2 ... second cutting groove, G3 ... measurement groove, L ... reference line.

Claims (1)

A chuck table for holding the workpiece, a first cutting means having a first cutting blade for cutting the workpiece held on the chuck table, and further cutting the region cut by the first cutting means Using a cutting apparatus comprising: a second cutting means having a second cutting blade that is thinner than the first cutting blade to be processed; and an imaging means for detecting a street that is a region to be cut.
A step of detecting a street of the work held on the chuck table by the imaging means, a step of forming a first cutting groove of a predetermined depth in the street of the work by the first cutting means, and the second Forming a second cutting groove along the first cutting groove by a cutting means, and the first cutting groove and the second cutting groove formed on the workpiece. A measurement method for measuring a position,
When measuring the position of the first cutting groove, the first cutting groove formed on the workpiece is imaged by the imaging means, and the positional relationship between the street and the first cutting groove is measured.
When measuring the position of the second cutting groove, the measuring groove is formed by the second cutting means on the street of the work before the first cutting groove is formed, and a predetermined position of the measuring groove is defined. Position the imaging means to image and measure the positional relationship between the street and the measurement groove,
The predetermined part of the measurement groove is a part moved from the reference line in the machining direction by an integral multiple of the street interval plus an alpha distance from an arbitrary street extending in the indexing direction as a reference line. Groove measurement method.

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