JP2015046541A - Method for detecting cut groove - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely detect a position of a cut groove, while work such as magnification change of imaging means can be eliminated even when the thickness of a cutting blade is larger than one field of view of the imaging means.SOLUTION: A width (y1) between a first edge (M1) and a second edge (M2) of a cut groove (M) is formed to be larger than an imaging field of view (14a) of imaging means (14). A method for detecting the cut groove includes the steps of: imaging a region including the first edge by the imaging means, and acquiring coordinate information of the first edge in the imaging field of view; moving the imaging means in a Y-axis direction which is a cutting indexing feed direction, and positioning the imaging means so that a region including the second edge of the cut groove enters the imaging field of view; imaging a region including the second edge by the imaging means, and acquiring coordinate information of the second edge in the imaging field of view; and calculating the width of the cut groove and the like from the coordinate information of the first and second edges and Y-axis direction movement amount information of the imaging means.

Description

  The present invention relates to a method for detecting a cutting groove formed on a wafer by cutting with a cutting blade.

  In order to divide a semiconductor wafer into individual chips, there has been proposed a cutting apparatus that forms a cutting groove with a cutting blade along a grid-like street on the surface of the semiconductor wafer (see Patent Document 1). The cutting apparatus of Patent Document 1 includes an imaging unit that detects an area to be cut, and a reference line formed on the imaging unit and a center position (center line) in the width direction of the cutting blade coincide with each other. It is positioned.

  In the cutting blade, the cutting position may be displaced due to displacement over time due to the fact that the spindle to be mounted expands or contracts due to the influence of the temperature of the cutting water or cutting point atmosphere, etc. due to operation. . Therefore, in Patent Document 1, in order to accurately perform the cutting along the street by the cutting blade, a step of periodically adjusting the position of the cutting blade is performed after the apparatus is operated for a predetermined time. In this step, first, the semiconductor wafer and the imaging unit are relatively moved, and the cutting groove is positioned immediately below the imaging unit. Next, the cutting groove is detected by the imaging means, and the displacement of the cutting blade is detected by measuring the deviation between the reference line formed in the imaging means and the center of the cutting groove. Then, the position of the cutting blade is adjusted by displacing the cutting blade in accordance with the detected amount of displacement of the cutting blade.

JP 2005-197492 A

  However, in the cutting apparatus of Patent Document 1, when the thickness of the cutting blade is larger than one field of view of the image pickup means, at least one of the edges on both sides of the cutting groove is out of the field of view range. For this reason, there is a problem that it becomes impossible to recognize the width and center position of the cutting groove from the detection result by the imaging means, and it becomes impossible to adjust the position of the cutting blade. Such a problem can be solved by changing the magnification of the microscope used for the imaging means to a low magnification, but since the change takes a lot of time, it is not practical, and the microscope has a low magnification, Another problem arises that the accuracy of recognizing the position of the cutting groove is reduced.

  The present invention has been made in view of the above problems, and its purpose is to eliminate work such as changing the magnification of the imaging means even when the thickness of the cutting blade is larger than one field of view of the imaging means, It is an object of the present invention to provide a method for detecting a cutting groove that can accurately detect the position of the cutting groove.

  The method for detecting a cutting groove according to the present invention includes a chuck table for holding the back side of a wafer having a dicing tape attached to the back surface and a device formed on the surface, and a cutting blade for cutting the wafer held by the chuck table. An imaging means having a predetermined imaging field for imaging the surface of the wafer held on the chuck table and having a reference line for detecting a position to be cut in the imaging field; A step of detecting a position to be cut of the wafer held on the chuck table by the imaging means, and a region to be cut of the wafer by the cutting means. When detecting the position of the cutting groove formed on the wafer during the process of forming the cutting groove on the wafer The width between the first edge that is one edge of the cutting groove and the second edge that is the other edge is larger than the imaging field of the imaging means, and the first edge of the cutting groove is in the imaging field. A first edge information acquisition step of positioning the imaging means so that a region including the first edge is included, imaging a region including the first edge, and acquiring position information of the first edge in the imaging field; After performing the edge information acquisition step, the imaging means is moved in the Y-axis direction that is the cutting index feed direction, and the imaging means is positioned so that the region including the second edge of the cutting groove enters the imaging field of view. After performing the second edge information acquisition step and the second edge information acquisition step of imaging the area including the edge and acquiring the position information of the second edge in the imaging field of view, the position of the first edge Information, second edge position information and Characterized in that it comprises a, a cutting groove position calculating step of calculating a positional relationship between the Y-axis direction movement amount cut groove from the information and the reference line image means.

  According to this method, the first edge in the cutting groove is imaged and then the imaging means is relatively moved, and then the second edge is imaged. Therefore, the thickness of the cutting blade (the width between each edge of the cutting groove) ) Is larger than one field of view of the imaging means, the width of the cutting groove and the like can be calculated with high accuracy. In addition, since it is not necessary to change the microscope used in the imaging means to a low magnification one, or to replace with a low magnification microscope, it is possible to image each edge of the cutting groove without changing the magnification with the same imaging means, The time required for detecting the cutting groove can be greatly shortened and efficiency can be improved. In addition, it is possible to take an image at a high magnification without reducing the magnification in the imaging means, and this can also improve the accuracy of the calculation result.

  According to the present invention, even when the thickness of the cutting blade is larger than one field of view of the image pickup means, operations such as changing the magnification of the image pickup means can be eliminated, and the position of the cutting groove can be detected with high accuracy.

It is a perspective view of the cutting device concerning this embodiment. It is a perspective view which shows the internal structure of the cutting device which concerns on this Embodiment. It is a schematic plan view of the wafer used as the cutting object which concerns on this Embodiment, and is explanatory drawing which shows the visual field of an imaging means.

  Hereinafter, a method for detecting a cutting groove according to the present embodiment will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of a cutting device according to the present embodiment, and FIG. 2 is a perspective view showing an internal structure of the cutting device. FIG. 3 is a schematic plan view of the wafer and is an explanatory view showing the field of view of the imaging means.

  As shown in FIG. 1, the cutting apparatus 1 is configured to process a disk-shaped wafer W held on a chuck table 3 on a housing 2 by a cutting means 4 provided above the chuck table 3. ing. Here, the wafer W to be cut will be described. The surface of the wafer W having a disk shape is partitioned into a plurality of regions by streets ST (see FIG. 3) serving as division lines arranged in a lattice pattern. Various devices D such as an IC, an LSI, or an LED are formed in the partitioned area. A dicing tape T is attached to the back surface of the wafer W, and the wafer W is mounted on the annular frame F via the dicing tape T.

  A rectangular opening 2 a extending in the X-axis direction is formed on the upper surface of the housing 2, and this opening 2 a is formed by a movable plate 31 that can move together with the chuck table 3 and a bellows-shaped waterproof cover 32. It is covered. Below the waterproof cover 32, a moving mechanism (not shown) for moving the chuck table 3 in the Y-axis direction is provided. On the surface of the chuck table 3, a holding surface 33 that sucks and holds the wafer W from the back side is formed of a porous ceramic material. The holding surface 33 is connected to a suction source (not shown) through a flow path in the chuck table 3. The chuck table 3 has a disk shape, and is provided so as to be rotatable about a disk center by a rotating means (not shown).

  The chuck table 3 is reciprocated between a delivery position at the center of the apparatus and a machining position facing the cutting means 4. FIG. 1 shows a state where the chuck table 3 stands by at the delivery position. In the housing 2, one corner portion adjacent to the delivery position is lowered by one step, and the mounting table 6 is provided at a lowered position so as to be lifted and lowered. On the mounting table 6, a cassette 5 containing wafers W is mounted. By moving the mounting table 6 up and down while the cassette 5 is mounted, the drawing position and the pushing position of the wafer W are adjusted in the height direction.

  1 is provided with a pair of guide rails 7 parallel to the Y-axis direction and a push-pull mechanism 8 for transporting the wafer W between the pair of guide rails 7 and the cassette 5. ing. The pair of guide rails 7 guide the conveyance of the wafer W by the push-pull mechanism 8 and position the wafer W in the X-axis direction. The push-pull mechanism 8 is configured to pull out the unprocessed wafer W from the cassette 5 to the pair of guide rails 7 and to push the processed wafer W into the cassette 5 from the pair of guide rails 7. The Y-axis direction of the wafer W is positioned by the push-pull mechanism 8.

  A first transfer arm 11 that transfers the wafer W between the guide rail 7 and the chuck table 3 is provided in the vicinity of the pair of guide rails 7. The wafer W is transferred by turning the L-shaped arm portion 16 of the first transfer arm 11 in a top view. Further, a spinner type cleaning mechanism 12 is provided on the right side of the chuck table 3 in the delivery position in FIG. In the cleaning mechanism 12, cleaning water is sprayed toward the rotating spinner table 17 to clean the wafer W, and then dry air is blown in place of the cleaning water to dry the wafer W.

  A support base 22 is provided on the housing 2, and a cantilever support portion 25 is provided on the support base 22 so as to cross over the movement path of the chuck table 3. As shown in FIG. 2, a ball screw type moving mechanism 60 that moves the cutting means 4 and the imaging means 14 in the Y-axis direction and the Z-axis direction is incorporated in the support base 22 and the cantilever support portion 25. The cutting mechanism 4 and the imaging means 14 are positioned above the chuck table 3 by the moving mechanism 60.

  The moving mechanism 60 includes a pair of guide rails 61 parallel to the Y-axis direction, and a motor-driven Y-axis table 62 that is slidably installed on the pair of guide rails 61. The Y-axis table 62 is formed in a rectangular shape when viewed from above, and a side wall 63 is erected at one end in the X-axis direction.

  The moving mechanism 60 includes a pair of guide rails 64 that are installed on the wall surface of the side wall 63 and parallel to the Z-axis direction, and a Z-axis table 65 that is slidably installed on the pair of guide rails 34. Yes. A spindle 41 of the cutting means 4 extending in the Y-axis direction toward the chuck table 3 is supported by the Z-axis table 65 in a cantilever manner. Further, nut portions (not shown) are formed on the back sides of the Y-axis table 62 and the Z-axis table 65, and a ball screw 66 (Z-axis ball screw not shown) is screwed to these nut portions. Drive motors 68 and 69 are connected to one end of each ball screw 66, respectively. The ball screw 66 is rotationally driven by the drive motors 68 and 69, and the cutting means 4 is moved along the guide rails 61 and 64 in the Y-axis direction and the Z-axis direction.

  The cutting means 4 has a cutting blade 42 provided at the tip of the spindle 41. The cutting blade 42 is covered with a blade cover 43, and the blade cover 43 is provided with an injection nozzle 44 that injects cutting water toward the cutting portion. In the cutting means 4, the cutting blade 42 is rotated at a high speed, and the wafer W is cut while jetting cutting water from the jet nozzle 44, whereby a cutting groove M (see FIG. 3) corresponding to the blade thickness of the cutting blade 42 is formed. Formed on the wafer W. Here, in the cutting groove M, the upper edge in FIG. 3 which is an edge on one side is a first edge M1, and the lower edge in FIG. 3 which is an edge on the other side is a second edge M2.

  The image pickup means 14 is provided so as to be able to pick up an image of the surface area of the wafer W projected at a predetermined magnification by a microscope. The image pickup means 14 includes an image pickup device (not shown) such as a CCD, and the image pickup device is composed of a plurality of pixels so that an electrical signal corresponding to the amount of light received by each pixel can be obtained. Therefore, the imaging means 14 can detect the street ST and the cutting groove M by imaging the surface of the wafer W. Here, the contents captured by the imaging unit 14 will be described. As shown in FIG. 3, the imaging means 14 images the first edge M1 and the second edge M2 of the cutting groove M extending in the X-axis direction in the imaging visual field 14a. The imaging means 14 includes a reference line 14b in the imaging visual field 14a. The reference line 14b is recognized in the state of extending in the X-axis direction within the imaging field 14a when imaging the first and second edges M1 and M2 in the cutting groove M, and from the imaging results of the edges M1 and M2. The position where the cutting groove M is to be cut is detected in the imaging field 14a.

  As shown in FIG. 1, a second transfer arm 13 that transfers the wafer W between the chuck table 3 and the cleaning mechanism 12 is provided on the side surface 23 of the support base 22. The arm portion 18 of the second transfer arm 13 extends obliquely forward, and the wafer W is transferred by moving the arm portion 18 in the Y-axis direction.

  At the foremost part of the housing 2, input means 55 is provided for receiving instructions to each part of the apparatus. Further, in the housing 2, a control unit 51 that performs overall control of each part of the cutting device 1 is provided. Various instructions are input to the control means 51 from the input means 55, and operations of components such as the chuck table 3 and the cutting means 4 of the cutting apparatus 1 are controlled based on the various instructions. The control means 51 is configured by a processor, a memory, and the like that operate each component of the cutting device 1. The memory is composed of one or a plurality of storage media such as a ROM (Read Only Memory) and a RAM (Random Access Memory) depending on the application.

  Next, a method for cutting the wafer W by the above-described cutting apparatus 1 will be described. Before performing the cutting process, the hairline alignment for matching the reference line 14b of the image pickup unit 14 and the center positions of the first and second edges M1 and M2 in the cutting groove M is completed, and the positional relationship between them. Is stored in the control means 51. In the cutting process, first, the wafer W mounted on the frame F is taken out from the cassette 5 via the dicing tape T, and the chuck table 3 is set so that the surface of the wafer W faces upward and the dicing tape T is positioned below the wafer W. It is conveyed upward and placed on the holding surface 33. Thereafter, the holding surface 33 communicates with a suction source (not shown), and the wafer W mounted on the frame F via the dicing tape T is sucked and held by the chuck table 3.

  After the wafer W is sucked and held, the chuck table 3 is moved in the X-axis direction, and the wafer W is positioned immediately below the imaging means 14. Next, the surface of the wafer W is imaged by the imaging means 14, and at least one of the plurality of streets ST that are positions where the cutting grooves M are to be formed is detected. Although this detected street ST is not particularly limited, in this embodiment, it is assumed that the street ST is located on one side of the wafer W in the Y-axis direction (the lowest side in FIG. 3). Then, by positioning the reference line 14b of the imaging unit 14 at the detected center position of the street ST, the center position of the cutting blade 42 in the Y-axis direction is controlled to coincide with the center position of the street ST.

  Next, the cutting means 4 is moved in the Z-axis direction, and the cutting blade 42 is positioned in the Z-axis direction so that the depth of the cutting groove M reaches halfway in the thickness direction of the dicing tape T. Thereafter, the chuck table 3 is relatively moved in the X-axis direction with respect to the cutting blade 42 rotated at a high speed, whereby a cutting groove M is formed along the street ST of the wafer W parallel to the X-axis. Then, every time one cutting groove M is formed, the cutting index feed direction (Y axis direction, FIG. 3) in which the cutting means 4 is on the other side in the Y axis direction of the wafer W by the pitch interval of the street ST in the Y axis direction. The cutting grooves M are sequentially formed by repeating the same operation. After the cutting grooves M are formed in all the streets ST parallel to the X axis, the chuck table 3 is rotated by 90 ° via a rotating means (not shown). Then, among the grid-like streets ST, the streets ST in which the cutting grooves M are not formed are made parallel to the X axis. From this state, the cutting grooves M are formed in all the streets ST parallel to the X axis in the same manner as described above, and the cutting grooves M are formed in all the lattice-shaped streets ST.

  Thus, when the cutting operation of the cutting groove M is continued, the spindle (not shown) of the cutting means 4 expands and contracts with time, and the cutting blade 42 is displaced in the Y-axis direction. As a result, even if the reference line 14b is aligned with the detected center position of the street ST, the center position of the cutting blade 42 in the Y-axis direction and the center position of the street ST are misaligned. In order to correct this deviation, the position of the most recently formed cutting groove M is detected as the displacement of the cutting blade 42. Such detection is periodically performed, for example, every time 10 streets ST are cut. Hereinafter, a method for detecting the position of the cutting groove M will be described.

  Here, as shown in FIG. 3, after 10 cutting grooves M are formed on the wafer W, the cutting operation of the cutting grooves M is interrupted, and the last cutting groove M formed is detected. It is assumed that the control means 51 recognizes the center position of the cutting groove M. Further, it is assumed that the width y1 in the Y-axis direction between the first and second edges M1 and M2 in the cutting groove M at the time of hairline alignment is formed larger than the width y2 in the Y-axis direction of the imaging visual field 14a.

  After the cutting operation of the cutting groove M is interrupted, the chuck table 3 is moved in the X-axis direction and the imaging means 14 is moved in the Y-axis direction, and the reference line 14b is located at the center position of the tenth cutting groove M recognized by the control means 51. The chuck table 3 and the imaging means 14 are positioned so that is positioned. However, since the cutting blade 42 is displaced in the Y-axis direction as described above, the reference line 14b of the positioned imaging means 14 is the tenth cutting groove M as in the imaging visual field 14a indicated by reference numeral V1 in FIG. Is shifted from the actual center position M3. Here, the imaging visual field 14a indicated by reference numeral V1 matches the reference line 14b with the center position of the tenth cutting groove M recognized by the control means 51 (hereinafter referred to as “assumed center position M4”). I am letting. Further, in the imaging field of view 14a indicated by reference numeral V1, the width y1 in the Y-axis direction between the first and second edges M1 and M2 in the cutting groove M is formed larger than the width y2 of the imaging field of view 14a in the Y-axis direction. Therefore, both the first and second edges M1 and M2 do not enter the imaging field of view 14a at the same time. Hereinafter, the case where the position of the cutting groove M is detected from the position indicated by the reference symbol V1 in the imaging visual field 14a will be described.

  The figure from which the imaging visual field 14a becomes the Y-axis direction of the predetermined amount wafer W which is a half of the width y3 (design value) of the cutting groove M from the position indicated by reference numeral V1 (position where the assumed center position M4 and the reference line 14b coincide). 3, the imaging means 14 is positioned so that the area including the first edge M1 of the cutting groove M enters the imaging visual field 14a as indicated by reference numeral V2 in FIG. Then, an area including the first edge M1 is imaged within the imaging field of view 14a of the imaging means 14 and image processing is performed, and the first edge M1 is detected. From this detection data, the amount of deviation of the first edge M1 relative to the reference line 14b is detected as a pixel value (for example, 1 pixel is 1 μm), and the amount of deviation is detected as the length b1, and the Y axis at the first edge M1 is detected. Directional position information is acquired (first edge information acquisition step). The position information of the first edge M1 acquired by the imaging unit 14 is output to and stored in the control unit 51.

  After performing the first edge information acquisition step, the imaging means 14 is moved downward in FIG. 3 which is in the Y-axis direction, so that the number of cutting grooves M in the imaging visual field 14a is indicated in FIG. The imaging means 14 is positioned so that the region including the second edge M2 is included (for example, the moving portion is moved by the design value of the width y3 of the cutting groove M). Then, an area including the second edge M2 is imaged within the imaging visual field 14a of the imaging means 14 and image processing is performed, and the second edge M2 is detected. From this detection data, the amount of deviation of the second edge M2 with respect to the reference line 14b is detected as a pixel value (for example, 1 pixel is 1 μm), and the amount of deviation is detected as the length b2, and the Y axis at the second edge M2 is detected. Direction position information is acquired (second edge information acquisition step). The position information of the second edge M2 acquired by the imaging unit 14 is output to and stored in the control unit 51. Note that there may be a case where a plurality of chips are partially formed at each of the edges M1 and M2. In this case, in the imaging means 14, the Y-axis direction that occurs most frequently in the extending direction of the edges M1 and M2 The coordinate information of is acquired.

  After performing the second edge information acquisition step, in the control means 51, from the stored position information of the first and second edges M1 and M2 and the information of the movement amount y3 in the Y-axis direction in the imaging means 14, The positional relationship between the width y1 of the cutting groove M and the reference line 14b is calculated (cutting groove position calculating step). For example, the width y1 of the cutting groove M is calculated as b1 + b2 + y3, and the amount of deviation between the center position M3 of the cutting groove M after the cutting operation and the reference line 14b (assumed center position M4) is calculated from the calculation result. The position of the cutting means 4 in the Y-axis direction is corrected by moving the cutting means 4 in the Y-axis direction by this amount of deviation. After this correction, the cutting operation of the interrupted cutting groove M is resumed.

  As shown by reference numerals V2 and V3 in FIG. 3, when the first edge M1 or the second edge M2 of the cutting groove M can be imaged in the imaging field 14a, first, the first and second images that can be imaged. Any one of the edges M1 and M2 is detected as described above. Thereafter, the imaging means 14 is moved in the Y-axis direction, and either one of the first and second edges M1 and M2 is detected in the same manner as described above, thereby calculating a deviation amount to be corrected by the cutting means 4. Can do.

  As described above, according to the present embodiment, even if the width y1 between the edges M1 and M2 in FIG. 3 is larger than the width y2 of the imaging field of view 14a, the positional information of the edges M1 and M2 in the cutting groove M. Can be obtained. In other words, both the edges M1 and M2 do not have to enter the imaging field of view 14a at the same time, and it is not necessary to replace the microscope with a low-magnification microscope in the imaging means 14, thereby shortening the working time. In addition, imaging can be performed with the microscope of the imaging unit 14 at a high magnification, and the width of the cutting groove M and the like can be calculated with high accuracy. Thereby, the position of the cutting blade 42 displaced due to expansion and contraction of the spindle (not shown) can be corrected with high accuracy, and the accuracy of the cutting position in the cutting groove M can be kept good.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, the method for acquiring the positional information of the first and second edges M1 and M2 and the method for calculating the positional relationship between the cutting groove M and the reference line 14b from the acquired information include the deviation in the Y-axis direction in the cutting means 4. It may be changed as long as the amount can be calculated.

  Further, in the above embodiment, after acquiring the position information of the first edge M1 in the imaging field of view 14a indicated by reference numeral V2 in FIG. 3, the imaging means 14 is moved by the design value of the width y3 of the cutting groove M. If the second edge M2 cannot be detected due to this movement, the following steps may be performed thereafter.

  From the imaging result of the imaging unit 14, the control unit 51 recognizes that the second edge M2 cannot be detected, and then moves the imaging unit 14 further in the Y-axis direction (here, the movement amount is y4). When the region including the second edge M2 of the cutting groove M enters the imaging field of view 14a and the second edge M2 is recognized, the amount of deviation of the second edge M2 with respect to the reference line 14b is detected as the length b3. . After this detection, the control means 51 calculates the width y1 of the cutting groove M as b1 + b3 + y3 + y4 based on the displacement amounts b1 and b3 and the information of the movement amount y3 + y4 in the Y-axis direction in the imaging means 14, and from this calculation result The deviation amount between the center position M3 of the cutting groove M and the reference line 14b (assumed center position M4) is calculated.

  As described above, the present invention provides a cutting groove when the width between the first edge that is one edge of the cutting groove and the second edge that is the other edge is larger than the imaging field of the imaging means. This is useful for a method of detecting the width of the image.

DESCRIPTION OF SYMBOLS 1 Cutting device 3 Chuck table 4 Cutting means 14 Imaging means 14a Imaging visual field 14b Base line D Device M Cutting groove M1 First edge M2 Second edge T Dicing tape W Wafer

Claims (1)

A chuck table for holding the back side of a wafer having a device formed on the front surface with a dicing tape adhered to the back surface, a cutting means comprising a cutting blade for cutting the wafer held on the chuck table, and An imaging means having a predetermined imaging field for imaging the surface of the wafer held by the chuck table and having a reference line for detecting a position to be cut in the imaging field, and relative to the imaging means and the chuck table A step of detecting a position to be cut of the wafer held on the chuck table by the image pickup means, and a cutting portion of the wafer to be cut by the cutting means. A method of detecting a cutting groove, wherein the position of the cutting groove formed on the wafer is detected during the step of forming the groove.
The width between the first edge that is one edge of the cutting groove and the second edge that is the other edge is larger than the imaging field of view of the imaging means,
The imaging means is positioned so that the region including the first edge of the cutting groove enters the imaging field of view, the region including the first edge is imaged, and the first edge in the imaging field of view is captured. A first edge information acquisition step of acquiring position information;
After performing the first edge information acquisition step, the imaging means is moved in the Y-axis direction which is the cutting index feed direction so that the region including the second edge of the cutting groove enters the imaging field of view. A second edge information acquisition step of positioning the imaging means, imaging a region including the second edge, and acquiring positional information of the second edge in the imaging field;
After performing the second edge information acquisition step, the cutting groove and the reference line are obtained from the position information of the first edge, the position information of the second edge, and the movement amount information of the imaging means in the Y-axis direction. Cutting groove position calculating step for calculating the positional relationship of
A method for detecting a cutting groove, comprising:

Images