Cutting device

Abstract

To provide a cutting device that can suppress a cutting groove from being wrongly detected due to forgetting of changing settings of a mask.SOLUTION: A cutting device 1 comprises a memorizing part 41, an image processing part 42 and a determining part 43. The memorizing part 41 memorizes a cutting condition for cutting a work-piece, confirmation items for confirming a quality of a cut groove and allowable values of the confirmation items and information about a thickness of a cutting blade 21. The image processing part 42 detects the cut groove from an image photographed with a photographing unit 30. The determining part 43 determines whether or not a plurality of confirmation items exceed the respective allowable values, on the basis of the cut groove detected by the image processing part 42. The image processing part 42 has a mask setting part 44 that masks regions on an inner side and an outer side with respect to respective edges of the cut groove, as regions other than detection objects. The mask setting part 44 calculates and sets the region correspondingly to the thickness of the cutting blade 21.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cutting device. [Background technology]

[0002] There is a known cutting process in which a cutting blade is used to form grooves in various plate-like workpieces such as semiconductor wafers and resin substrates to form chips for multiple devices or to remove layers of devices formed on streets (planned dividing lines). The cutting grooves are processed under predetermined processing conditions so that they are formed in the center of the streets with a chipping of a specified size or less.

[0003] However, due to individual differences in the workpiece, clogging of the cutting blade, slight expansion and contraction of the axis of the cutting device, etc., the position of the cutting groove may be shifted from the center of the street (off-center), and large chipping may occur suddenly. For this reason, the cutting device is equipped with an automatic inspection function called kerf check, which automatically photographs the cutting groove and observes the condition. In the kerf check, the street of the workpiece is photographed during processing, and the edges of the cutting groove are detected by image processing. This automatically detects the width of the cutting groove, the off-center of the cutting groove, and the size and frequency of chipping that occurs in the cutting groove, and automatically checks whether any abnormality has occurred by comparing it with a preset threshold value (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6029271 Summary of the Invention [Problem to be solved by the invention]

[0005] In the captured image processed by Kerf Check, the cutting groove is dark and the area where the cutting groove of the street is not formed is bright. However, if the cutting groove is shallow and thick, the center of the cutting groove is likely to be bright due to the lighting, and there is a risk of misidentifying that two cutting grooves have been formed. In addition, if the TEG (Test Element Group) formed on the street is displayed dark, the TEG may be mistakenly recognized as chipping. Therefore, it is possible to prevent misrecognition by setting a mask on the center or both sides of the cutting groove. However, if the size of the cutting blade is changed, for example to a thin blade, and the mask setting is forgotten to be changed, there is a risk of an error in which the cutting groove is hidden by the mask in the center and the cutting groove cannot be found.

[0006] The present invention has been made in consideration of such problems, and has as its object to provide a cutting device that can prevent erroneous detection of cutting grooves due to forgetting to change the mask settings. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, a cutting device of the present invention is a cutting device including a chuck table for holding a workpiece, and a cutting unit for forming a cut groove in the workpiece held on the chuck table with a cutting blade attached to a spindle, the cutting device including an imaging unit for imaging the cut groove formed in the workpiece during processing to obtain a captured image, a memory unit for storing cutting conditions for cutting the workpiece, check items for checking the quality of the cut groove and allowable values ​​for the check items, and information on the blade thickness of the cutting blade, an image processing unit for detecting the cut groove from the captured image, a determination unit for determining whether or not a plurality of the check items have exceeded their respective allowable values ​​based on the cut groove detected by the image processing unit, and a notification unit for notifying the result of the determination by the determination unit, the image processing unit having a mask setting unit for masking an area inside or outside both banks of the cut groove as an area outside the detection target for the cut groove when detecting the cut groove from the captured image, the mask setting unit comprising: The data stored in the storage unit The area is calculated and set in accordance with the cutting blade thickness. The memory unit may further store the difference between the blade thickness of the cutting blade and the width of the inner region, and the mask setting unit may calculate the width based on the blade thickness of the cutting blade and the difference, and set the inner region. Effect of the Invention

[0008] The present invention can prevent erroneous detection of cut grooves due to forgetting to change the mask settings. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an example of the configuration of a cutting device according to an embodiment. [Diagram 2] FIG. 2 is a perspective view showing an example of a workpiece to be processed by the cutting device of FIG. [Diagram 3] FIG. 3 is a diagram illustrating an example of condition data stored in the storage unit of FIG. [Figure 4] FIG. 4 is a diagram showing an example of mask setting data stored in the storage unit of FIG. [Diagram 5] FIG. 5 is a cross-sectional view showing an example of a cutting operation of the cutting device of FIG. [Figure 6] FIG. 6 is a cross-sectional view showing an example of an imaging operation of the cutting device of FIG. [Figure 7] FIG. 7 is a diagram showing an example of a display screen of the result of the kerf check in the cutting device of FIG. [Figure 8] FIG. 8 is a diagram showing another example of the result display screen of the kerf check in the cutting device of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiment. Furthermore, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described below can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the configurations can be made without departing from the gist of the present invention.

[0011] [Embodiment] A cutting device 1 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an example of the configuration of the cutting device 1 according to the embodiment. FIG. 2 is a perspective view showing an example of a workpiece 100 to be processed by the cutting device 1 of FIG. 1. FIG. 3 is a diagram showing an example of condition data 300 stored in the storage unit 41 of FIG. 1. FIG. 4 is a diagram showing an example of mask setting data 350 stored in the storage unit 41 of FIG. 1. As shown in FIG. 1, the cutting device 1 according to the embodiment includes a chuck table 10, a cutting unit 20, an imaging unit 30, a control unit 40, a notification unit 50, and a cassette mounting table 60.

[0012] In this embodiment, the workpiece 100 to be cut by the cutting device 1 is, as shown in FIG. 2, a disk-shaped semiconductor wafer or an optical device wafer made of a base material such as silicon, sapphire, silicon carbide (SiC), or gallium arsenide. The workpiece 100 has a flat surface 101 on which a chip-sized device 103 is formed in an area partitioned by a plurality of streets (planned division lines) 102 formed in a lattice pattern. In this embodiment, the workpiece 100 has an adhesive tape 105 attached to a back surface 104 on the back side of the front surface 101, and an annular frame 106 attached to the outer edge of the adhesive tape 105, but the present invention is not limited to this. In addition, the workpiece 100 may be a rectangular package substrate having a plurality of devices sealed with resin, a ceramic plate, a glass plate, or the like. In this embodiment, the workpiece 100 has a TEG (Test Element Group) (not shown) made of metal formed in the outer widthwise region of the street 102, but the present invention is not limited to this, and a TEG may not be formed, and other dummy patterns may be formed in a similar region.

[0013] The chuck table 10 includes a disk-shaped frame body with a recess formed therein and a disk-shaped suction part fitted into the recess. The suction part of the chuck table 10 is formed of a porous ceramic or the like with a large number of porous holes, and is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown). The upper surface of the suction part of the chuck table 10 is a holding surface 11 on which the workpiece 100 is placed and which suction-holds the placed workpiece 100. In this embodiment, the holding surface 11 is a surface on which the workpiece 100 is placed with its front surface 101 facing upward, and suction-holds the placed workpiece 100 from its back surface 104 side via an adhesive tape 105. The holding surface 11 and the upper surface of the frame body of the chuck table 10 are arranged on the same plane and are formed parallel to the XY plane, which is a horizontal plane. The chuck table 10 is movable in the X-axis direction, which is one horizontal direction, by an X-axis moving unit (not shown), and is rotatable around the Z-axis, which is in the vertical direction and perpendicular to the XY plane, by a rotary drive source (not shown).

[0014] As shown in FIG. 1, the cutting unit 20 has a cutting blade 21 and a spindle 22. The cutting blade 21 is attached to the tip of the spindle 22, and is rotated around an axis parallel to a Y direction that is another horizontal direction and perpendicular to the X direction, to cut the workpiece 100 held on the chuck table 10. The cutting unit 20 is provided so as to be movable in the Y-axis direction by a Y-axis moving unit with respect to the workpiece 100 held on the chuck table 10, and is also provided so as to be movable in the Z-axis direction by a Z-axis moving unit (not shown). The cutting device 1 is a so-called facing dual type cutting device, in which the cutting unit 20 has two cutting blades 21 facing each other in the Y-axis direction, that is, a two-spindle dicer.

[0015] The cutting blade 21 has an annular cutting edge 21-1 (see Figs. 5 and 6) made of abrasive grains such as diamond or CBN (Cubic Boron Nitride) and a bonding material such as metal or resin, and is formed to a predetermined thickness (blade thickness 21-2 (see Figs. 5 and 6)). The cutting blade 21 sharpens itself by wearing down the cutting edge 21-1 as cutting is performed, and a certain level of sharpness is always maintained.

[0016] In this embodiment, the cutting unit 20 has a mechanism for acquiring information on the type of the cutting blade 21 attached to the tip of the spindle 22. The cutting unit 20 may acquire information on the type of the cutting blade 21 attached to the tip of the spindle 22 by, for example, reading an identifier such as a barcode attached to an inner peripheral area of ​​the cutting edge 21-1 of the cutting blade 21 attached to the tip of the spindle 22 with a predetermined reader, or may acquire information on the type of the cutting blade 21 to be newly attached by reading an identifier attached to a case that contains the newly attached cutting blade 21 with a predetermined reader when changing the cutting blade 21. In addition, in response to receiving an input of the type of the cutting blade 21 from an operator or the like, the cutting blade 21 attached to the tip of the spindle 22 may be changed to the corresponding type. The cutting unit 20 outputs the acquired information on the type of the cutting blade 21 to the control unit 40.

[0017] The imaging unit 30 includes an imaging element that images a surface 101 including streets 102 of the workpiece 100 before cutting, and a cut groove 200 (see FIGS. 5 and 6) formed in the workpiece 100 after cutting. The imaging element is, for example, a CCD (Charge-Coupled Device) imaging element or a CMOS (Complementary MOS) imaging element. In this embodiment, the imaging unit 30 is fixed to the cutting unit 20 so as to move integrally with the cutting unit 20.

[0018] The imaging unit 30 captures an image of the workpiece 100 before cutting held on the chuck table 10, obtains an image for performing alignment for aligning the workpiece 100 and the cutting blade 21, and outputs the obtained image to the control unit 40. The imaging unit 30 also captures an image of the workpiece 100 after cutting held on the chuck table 10, obtains captured images 401, 402 (see Figs. 7 and 8) for performing a so-called kerf (groove) check to automatically check the quality of the cut groove 200 formed by cutting the workpiece 100, such as whether the cut groove 200 is contained within the street 102 and whether any large chipping has occurred, and outputs the obtained captured images 401, 402 to the control unit 40. Note that the captured images captured by the imaging unit 30 and output to the control unit 40 are not limited to the captured images 401, 402 shown in Figs. 7 and 8.

[0019] The control unit 40 controls the operation of each component of the cutting device 1 to cause the cutting device 1 to perform cutting processing of the workpiece 100. As shown in FIG. 1, the control unit 40 includes a storage unit 41, an image processing unit 42, and a judgment unit 43. As shown in FIG. 3, the storage unit 41 stores, as condition data 300, the cutting conditions under which the cutting device 1 cuts the workpiece 100, the check items in the kerf check and the allowable values ​​that define the ranges for judging whether the check items pass or fail, and information on the type of the cutting blade 21, including information on the blade thickness 21-2 of the cutting blade 21, in association with each other. The storage unit 41 stores one or more pieces of condition data 300 for each blade thickness 21-2 of the cutting blade 21. The condition data 300 is data used by the control unit 40 when controlling the cutting device 1 to perform cutting processing of the workpiece 100 or when performing a kerf check, in accordance with the blade thickness 21-2 of the cutting blade 21.

[0020] As shown in Fig. 3, the storage unit 41 stores the cutting conditions in the condition data 300 by correlating the items of the cutting conditions with the numerical values ​​and contents of the items of the cutting conditions. Here, in the example shown in Fig. 3, the items of the cutting conditions in the condition data 300 stored in the storage unit 41 include items of conditions related to the workpiece 100, such as the shape of the workpiece 100, the outer diameter of the workpiece 100, the thickness of the workpiece 100, the width 110 (see Figs. 7 and 8) of the streets 102 formed in the workpiece 100, and the index amount indicating the distance between adjacent streets 102, and items of conditions related to the cutting process, such as the number of rotations per unit time (rotation speed) of the spindle 22 that rotates the cutting blade 21, the processing feed rate, the cutting depth, the cutting order of the streets 102, and the like. The shape of the workpiece 100 indicates whether the workpiece 100 is disc-shaped or rectangular, and the like. The processing feed speed is the speed at which the cutting blade 21 of the cutting unit 20 moves in the processing feed direction (X-axis direction in FIG. 1) relative to the workpiece 100 on the chuck table 10. The cutting depth is the position (depth) of the cutting blade 21 of the cutting unit 20 relative to the workpiece 100 on the chuck table 10 in the cutting depth direction (Z-axis direction in FIG. 1) during cutting, and determines the depth of the cut groove 200 to be formed.

[0021] As shown in Fig. 3, the storage unit 41 stores, in the condition data 300, the check items in the kerf check and the allowable values ​​that define the ranges for judging whether the check items pass or fail, in a corresponding manner. Here, the check items in the kerf check in the condition data 300 stored in the storage unit 41 include, in the example shown in Fig. 3, the off-center 202 (see Fig. 8), the kerf width Max 203 (see Fig. 8), the kerf width Min 204 (see Fig. 8), the chipping width 205 (see Fig. 8) from the kerf center 201 (see Fig. 8), the Max chipping width 206 (see Fig. 8) from the kerf end, and the like. The off-center 202 is the value of the deviation in the width direction of the kerf center 201, which is the center line that represents the center position of the cutting groove 200 in the width direction, from the center line 111 (see Fig. 8) of the street 102. The kerf width Max 203 and the kerf width Min 204 are respectively the maximum and minimum values ​​of the distance (spacing) between both ends 220 of the cut groove 200 in the area checked by the kerf check (within the photographed images 401, 402). The chipping width 205 from the kerf center 201 is the distance between the end of the largest chipping in the width direction in the photographed images 401, 402 and the center of the cut groove 200 in the width direction. The Max chipping width 206 from the kerf end is the distance between the end of the largest chipping in the width direction in the photographed images 401, 402 and the end of the cut groove 200. The tolerances are threshold values ​​for the judging unit 43 to judge whether each check item is normal or abnormal.

[0022] As shown in Fig. 3, the storage unit 41 stores information on the type of the cutting blade 21 in the condition data 300 by correlating the item of the cutting blade 21 with the numerical value and contents of the item of the cutting blade 21. Here, in the example shown in Fig. 3, the items of information on the cutting blade 21 in the condition data 300 stored in the storage unit 41 include the type of the cutting blade 21, the material of the cutting edge 21-1 of the cutting blade 21, the blade thickness 21-2 of the cutting edge 21-1 of the cutting blade 21, etc. The type of the cutting blade 21 indicates whether the cutting blade 21 is a hub blade having a hub or a hubless blade having no hub. The material of the cutting edge 21-1 of the cutting blade 21 includes the material of the abrasive grains and the material of the bond material.

[0023] The memory unit 41 also stores various data required when the image processing unit 42 performs the image processing described below, such as data on brightness thresholds and reference values ​​used by the image processing unit 42 when detecting the cutting groove 200 based on the captured images 401, 402, layout data and data on various image elements used by the image processing unit 42 to generate result display screens 501, 502, etc.

[0024] 4, the storage unit 41 stores information on a width 421 (see FIGS. 7 and 8) of an inner mask 411 (see FIGS. 7 and 8) set by a mask setting unit 44 (described later) of the image processing unit 42 corresponding to the blade thickness 21-2 of the cutting blade 21 and a separation width 422 (see FIGS. 7 and 8) between a pair of outer masks 412 (see FIGS. 7 and 8) as mask setting data 350. As shown in FIG. 4, the storage unit 41 stores, in the mask setting data 350, the width 421 of the inner mask 411 and the separation width 422 between the pair of outer masks 412 as differences (relative values) from the blade thickness 21-2 of the cutting edge 21-1 of the cutting blade 21 used when forming the cutting groove 200 to be kerf checked. 4, in the mask setting data 350, a negative value shown in the column to the right of the mask (inner) representing the width 421 of the inner mask 411 indicates that it is narrower than the blade thickness 21-2 of the cutting blade 21, and a positive value shown in the column to the right of the mask (outer) representing the separation width 422 of the pair of outer masks 412 indicates that it is wider than the blade thickness 21-2 of the cutting blade 21. The mask setting data 350 is data used by the mask setting unit 44 when setting a mask.

[0025] The inner mask 411 and the pair of outer masks 412 are both masks for information processing that are set by the mask setting unit 44 to be superimposed on the photographed images 401, 402. The inner mask 411 is a mask that is superimposed on the inside of both sides (edges) 210 of the cutting groove 200 in the photographed images 401, 402, and has a horizontally long rectangular area with a width 421 in the vertical direction in the photographed images 401, 402. The pair of outer masks 412 are masks that are superimposed on both sides of both sides (edges) 210 of the cutting groove 200 in the photographed images 401, 402, and have a pair of horizontally long rectangular areas that extend in the horizontal direction in the photographed images 401, 402 and are spaced apart by a separation width 422 in the vertical direction, with the area of ​​the upper mask portion reaching the upper end of the photographed images 401, 402, and the area of ​​the lower mask portion reaching the lower end of the photographed images 401, 402.

[0026] In the mask setting data 350, the difference between the width 421 of the inner mask 411 and the blade thickness 21-2 of the cutting blade 21 is set to a predetermined value that allows the inner mask 411 to completely cover the area of ​​the cutting groove 200, which is imaged with high brightness, without partially covering both sides (edges) 210 of the cutting groove 200, and to completely cover the area of ​​the cutting groove 200, which is imaged with high brightness, in the central area in the width direction of the cutting groove 200, which will be described later, when none of the allowable values ​​of the check items in the kerf check of the condition data 300 are exceeded. In the mask setting data 350, the difference between the separation width 422 of the pair of outer masks 412 and the blade thickness 21-2 of the cutting blade 21 is set to a predetermined value that allows the pair of outer masks 412 to completely cover the TEG formed in the outer area in the width direction of the street 102, without partially covering both sides (edges) 210 of the cutting groove 200, and to completely cover the TEG formed in the outer area in the width direction of the street 102, when none of the allowable values ​​of the check items in the kerf check of the condition data 300 are exceeded.

[0027] The present invention is not limited to the above embodiment, and the storage unit 41 may store mask setting data for each blade thickness 21-2 of the cutting blade 21, and in this mask setting data, the width 421 of the inner mask 411 and the separation width 422 of the pair of outer masks 412 may both be stored as absolute values. When the storage unit 41 stores the width 421 of the inner mask 411 and the separation width 422 of the pair of outer masks 412 as absolute values, the storage unit 41 may store them as a set of data in association with the condition data 300 in which the blade thickness 21-2 of the cutting blade 21 is the same.

[0028] The image processing unit 42 has a mask setting unit 44 as shown in FIG. 1. The mask setting unit 44 calculates and sets the area of ​​the inner mask 411 and the pair of outer masks 412 corresponding to the blade thickness 21-2 of the cutting blade 21, and masks the area as an area not to be detected for the cut groove 200. As shown in FIG. 7 and FIG. 8, the image processing unit 42 sets the inner mask 411 and the pair of outer masks 412 on the captured images 401, 402 including the street 102 and the cut groove 200 captured by the imaging unit 30 by the mask setting unit 44, and then detects the cut groove 200 based on the captured images 401, 402 in which these masks are set. The determination unit 43 determines whether or not a plurality of check items in the kerf check exceed the allowable values ​​set for each of them in the condition data 300 based on the cut groove 200 detected by the image processing unit 42. Details of the processing by the image processing unit 42, the determination unit 43, and the mask setting unit 44 will be described in the description of the operation of the cutting device 1 described later.

[0029] In this embodiment, the control unit 40 includes a computer system. The computer system included in the control unit 40 includes an arithmetic processing device having a microprocessor such as a CPU (Central Processing Unit), a storage device having a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and an input / output interface device. In this embodiment, the function of the control unit 40 is realized by the arithmetic processing device of the computer system included in the control unit 40 executing a computer program stored in the storage device of the computer system included in the control unit 40. The arithmetic processing device of the control unit 40 performs arithmetic processing according to the computer program stored in the storage device of the control unit 40, and outputs a control signal for controlling the cutting device 1 to each component of the cutting device 1 via the input / output interface device of the control unit 40.

[0030] In this embodiment, the function of the storage unit 41 is realized by a storage device of a computer system included in the control unit 40. In this embodiment, the functions of the image processing unit 42, the determination unit 43, and the mask setting unit 44 are realized by an arithmetic processing unit of the computer system included in the control unit 40 executing a computer program stored in the storage device of the computer system included in the control unit 40.

[0031] The notification unit 50 notifies the result of the determination made by the determination unit 43 as to whether or not a plurality of check items in the kerf check exceed the tolerances set for each of them. As shown in FIG. 1, the notification unit 50 has a display unit 51 and a light-emitting unit 52. The display unit 51 is configured with a condition editing screen for editing the condition data 300 stored in the storage unit 41, and a liquid crystal display device for displaying the status and images of various operations of the cutting device 1 such as cutting operations and imaging operations. The display unit 51 switches the screens and images to be displayed by being controlled by the control unit 40. The display unit 51 notifies the result of the determination made by the determination unit 43 to the operator of the cutting device 1, etc., by displaying result display screens 501 and 502 showing the result of the determination made by the determination unit 43.

[0032] The light-emitting unit 52 is composed of a light-emitting diode or the like, and is controlled by the control unit 40 to light up, blink, and turn off. The light-emitting unit 52 lights up, blinks, and turns off to notify the operator of the cutting device 1 of the result of the judgment by the judgment unit 43, for example, in the form of whether the judgment result is pass or fail. The notification unit 50 is not limited to this in the present invention, and may also be provided with an audio unit composed of a speaker or the like that emits sound.

[0033] The display unit 51 is also provided with an input unit 53 that is used when an operator or the like inputs various information or the like to edit the condition data 300. In this embodiment, the input unit 53 is configured with at least one of a touch panel provided on the display unit 51 and a keyboard or the like.

[0034] The cassette mounting table 60 is a mounting table for mounting a cassette, which is a container for housing a plurality of workpieces 100, and raises and lowers the mounted cassette in the Z-axis direction. The workpieces 100 before cutting, housed in a cassette mounted on the cassette mounting table 60, are transported one by one by a transport unit (not shown) to the chuck table 10, undergo cutting processing by the cutting unit 20 and cleaning processing by a cleaning unit (not shown), and are then housed again in the cassette by the transport unit.

[0035] Next, this specification will explain the operation and processing of the cutting device 1 according to the embodiment with reference to the drawings. Fig. 5 is a cross-sectional view showing an example of the cutting operation of the cutting device 1 of Fig. 1. Fig. 6 is a cross-sectional view showing an example of the imaging operation of the cutting device 1 of Fig. 1. Fig. 7 is a diagram showing a result display screen 501 which is an example of the result display screen of the kerf check in the cutting device 1 of Fig. 1. Fig. 8 is a diagram showing a result display screen 502 which is another example of the result display screen of the kerf check in the cutting device 1 of Fig. 1.

[0036] The control unit 40 first obtains information on the type of the cutting blade 21 attached to the spindle 22 from the cutting unit 20, and obtains information on the blade thickness 21-2 of the cutting blade 21 attached to the spindle 22 based on the information on the type of the cutting blade 21 obtained from the cutting unit 20. Based on the obtained information on the blade thickness 21-2 of the cutting blade 21, the control unit 40 selects condition data 300 that can be used when controlling the cutting device 1 to perform the cutting process of the workpiece 100 and when performing a kerf check on the cut groove 200 formed in the cutting process, requests an operator or the like to input which of the selected condition data 300 to use, and determines the condition data 300 to be used in response to the input received from the operator or the like.

[0037] The control unit 40 refers to the condition data 300 determined based on the information on the blade thickness 21-2 of the cutting blade 21, and causes the cutting device 1 to perform a cutting operation according to the cutting conditions of the condition data 300. Specifically, the control unit 40 first controls the chuck table 10 to suction-hold the workpiece 100 according to the cutting conditions of the condition data 300 from the back surface 104 side on the holding surface 11 of the chuck table 10 via the adhesive tape 105, and then controls the imaging unit 30 to obtain an image for performing alignment, and performs the alignment. Next, as shown in FIG. 5, the control unit 40 controls the spindle 22 to rotate the cutting blade 21 in accordance with the cutting conditions of the condition data 300, while controlling the X-axis moving unit, the Y-axis moving unit and the Z-axis moving unit to move the cutting blade 21 relative to the workpiece 100 held on the chuck table 10 along the streets 102, thereby cutting the workpiece 100 with the cutting blade 21 to form a cutting groove 200 along the streets 102.

[0038] After forming the cut groove 200 along the street 102, the control unit 40 controls the imaging unit 30 to capture an image of an area straddling one street 102 and the cut groove 200 on the surface 101 of the workpiece 100 after cutting, as shown in Fig. 6, and performs an imaging operation to obtain captured images 401, 402 for performing a kerf check, etc. In this embodiment, as shown in Figs. 7 and 8, the imaging unit 30 captures the captured images 401, 402 by setting an imaging magnification and an angle of view so that only one street 102 extending laterally and only one cut groove 200 formed along the street 102 are positioned in the center of the captured images 401, 402 in the width direction in the captured images 401, 402.

[0039] In the present embodiment shown in Fig. 6, the control unit 40 captures the previously formed cut groove 200 before forming the cut groove 200 along all the streets 102, i.e., during the machining of the workpiece 100, to obtain the captured images 401, 402. Therefore, in the present embodiment, if an abnormality occurs in the cut groove 200 during the machining of the workpiece 100, it is possible to quickly respond to the abnormality. Note that the present invention is not limited to this, and the cut groove 200 may be captured and the captured images 401, 402 obtained after the cut groove 200 is formed along all the streets 102, i.e., after the machining of the workpiece 100.

[0040] In the captured images 401 and 402 obtained by the control unit 40 capturing images with the imaging unit 30, the cutting groove 200 formed on the surface 101 of the workpiece 100 hardly reflects the illumination light, so the amount of light incident on the imaging element of the imaging unit 30 is small, and the image is captured with low brightness. However, in the captured images 401 and 402, for example, if the cutting groove 200 formed is shallow and wide, the central region in the width direction of the cutting groove 200 reflects the illumination light, so the amount of light incident on the imaging element of the imaging unit 30 is large, and the image may be captured with high brightness. In this embodiment, the brightness in the captured images 401 and 402 is specified in multiple gradations, for example, 256 gradations, and is expressed as an integer value from 0 to 255, with the darkest being represented by the minimum value 0, the brightest being represented by the maximum value 255, and the brighter the image, the larger the value.

[0041] Therefore, before the image processing unit 42 detects the cutting groove 200 from the captured images 401, 402, the mask setting unit 44 automatically sets an inner mask 411 in the area widthwise inside of both banks (edges) 210 of the cutting groove 200 in accordance with the blade thickness 21-2 of the cutting blade 21, thereby masking the inner area as an area outside the detection target of the cutting groove 200, thereby reducing the risk that the image processing unit 42 will erroneously detect an area in the widthwise central area of ​​the cutting groove 200 that is imaged with high brightness as being an area outside the both banks (edges) 210 of the cutting groove 200.

[0042] Specifically, the mask setting unit 44 first refers to the mask setting data 350 stored in the storage unit 41, and calculates the width 421 of the inner mask 411 by subtracting a difference (relative value, 0.015 mm in the example shown in FIG. 4) corresponding to the width 421 of the inner mask 411 in the mask setting data 350 from the blade thickness 21-2 of the cutting blade 21. The mask setting unit 44 then sets the inner mask 411 by superimposing the inner mask 411 of the calculated width 421 on the central region of the street 102 in the captured images 401 and 402 so that the center line of the inner mask 411 and the center line 111 of the street 102 overlap, for example, as shown in FIGS. 7 and 8. Note that in this embodiment, the center line 111 of the street 102 overlaps with the center line extending in the horizontal direction in the captured images 401 and 402. In the example shown in Figure 7, the mask setting unit 44 sets an inner mask 411 having a width 421 of 0.010 mm superimposed on the captured image 401 in response to the blade thickness 21-2 of the cutting blade 21 being 0.025 mm, and in the example shown in Figure 8, the mask setting unit 44 sets an inner mask 411 having a width 421 of 0.025 mm superimposed on the captured image 402 in response to the blade thickness 21-2 of the cutting blade 21 being 0.040 mm.

[0043] In addition, in the captured images 401 and 402, the surface 101 of the workpiece 100 reflects the illumination light favorably, so the amount of light incident on the imaging element of the imaging unit 30 is large and the image is captured with high brightness. However, in the captured images 401 and 402, since the TEG is formed in the outer region in the width direction of the street 102, the TEG positioned in the outer region in the width direction of the cut groove 200 has an area that hardly reflects the illumination light, so the amount of light incident on the imaging element of the imaging unit 30 is small, and there is a risk that the brightness of that area will be low.

[0044] Therefore, before the image processing unit 42 detects the cutting groove 200 from the captured images 401, 402, the mask setting unit 44 automatically sets a pair of outer masks 412 in the area widthwise outer than both banks (edges) 210 of the cutting groove 200 in accordance with the blade thickness 21-2 of the cutting blade 21, thereby masking the outer area as an area outside the detection target of the cutting groove 200, thereby reducing the risk that the image processing unit 42 will erroneously detect an area of ​​the TEG positioned widthwise outer of the cutting groove 200 that is imaged with low brightness as being part of the cutting groove 200.

[0045] Specifically, the mask setting unit 44 first refers to the mask setting data 350 stored in the storage unit 41, and calculates the separation width 422 of the pair of outer masks 412 by adding a difference (relative value, 0.040 mm in the example shown in FIG. 4) corresponding to the separation width 422 of the pair of outer masks 412 in the mask setting data 350 to the blade thickness 21-2 of the cutting blade 21. The mask setting unit 44 then sets the pair of outer masks 412 by superimposing the pair of outer masks 412 having the calculated separation width 422 on the upper and lower regions of the captured images 401, 402 so that, for example, a center line that bisects the separation width 422 of the pair of outer masks 412 and the center line 111 of the street 102 overlap each other, as shown in FIG. 7 and FIG. 8. In the example shown in Figure 7, the mask setting unit 44 sets a pair of outer masks 412 with a separation width 422 of 0.065 mm superimposed on the captured image 401 in correspondence with the blade thickness 21-2 of the cutting blade 21 being 0.025 mm, and in the example shown in Figure 8, the mask setting unit 44 sets a pair of outer masks 412 with a separation width 422 of 0.080 mm superimposed on the captured image 402 in correspondence with the blade thickness 21-2 of the cutting blade 21 being 0.040 mm.

[0046] In this embodiment, the mask setting unit 44 sets an inner mask 411 and a pair of outer masks 412, but the present invention is not limited to this. For example, when the central region of the cutting groove 200 is unlikely to reflect the illumination light in order to form the cutting groove 200 deep or narrow, the setting of the inner mask 411 may be omitted, and when a TEG is not formed in the outer region of the street 102 of the workpiece 100 in the width direction, the setting of the pair of outer masks 412 may be omitted.

[0047] After the mask setting unit 44 sets the inner mask 411 and the pair of outer masks 412, the image processing unit 42 detects, in the remaining area obtained by removing the areas where the inner mask 411 and the pair of outer masks 412 are set from the captured images 401, 402, an area having a luminance equal to or less than a predetermined threshold value that is lower than the luminance when the surface 101 of the workpiece 100 is imaged and higher than the luminance when the cutting groove 200 is imaged, as a part of the area where the cutting groove 200 is formed on the surface 101 of the workpiece 100. In addition, the image processing unit 42 processes the area where the inner mask 411 is set as a part of the remaining area where the cutting groove 200 is formed on the surface 101 of the workpiece 100, and processes the areas other than the area where the cutting groove 200 is formed in the captured images 401, 402 (including the area where the pair of outer masks 412 are set) as an area where the cutting groove 200 is not formed.

[0048] The image processing unit 42 further detects the boundary region between the region where the cut groove 200 is formed on the surface 101 of the workpiece 100 and the region where the cut groove 200 is not formed on the surface 101 of the workpiece 100 as both sides (edges) 210 of the cut groove 200. The image processing unit 42 also detects linear both ends 220 of the cut groove 200 by performing a calculation process for linearly connecting extreme values ​​protruding inward in the width direction of the cut groove 200 for each edge 210 of the cut groove 200 based on both sides (edges) 210 of the cut groove 200. Here, the both ends 220 of the cut groove 200 are lines obtained by removing the region caused by chipping generated in the cut groove 200 from both sides (edges) 210 of the cut groove 200, and are lines representing the width (kerf width) of the cut groove 200 from which the chipping has been removed. Both ends 220 of the cut groove 200 are one of the reference lines for measuring the size of the chipping protruding in the width direction. The image processing unit 42 detects a kerf center 201 of the cut groove 200 by calculating the center line of both ends 220 of the cut groove 200 based on both ends 220 of the cut groove 200. The kerf center 201 is a line that indicates the position of the cut groove 200 in the width direction, and is another reference line for measuring the size of the chipping in the width direction.

[0049] The image processing unit 42 detects multiple confirmation items in the kerf check, namely, off-center 202, kerf width Max 203, kerf width Min 204, chipping width 205 from the kerf center 201, and maximum chipping width 206 from the kerf end, based on the detected edges 210, both ends 220, and kerf center 201 of the cutting groove 200, and the center line 111 of the street 102 that is set in advance in the center of the captured images 401, 402.

[0050] The determination unit 43 determines whether or not the detection value detected by the image processing unit 42 exceeds the allowable value stored in the storage unit 41 as the condition data 300 for each of the multiple check items in the kerf check. For check items that specify the maximum allowable value (in this embodiment, the off-center 202, the kerf width Max 203, the chipping width 205 from the kerf center 201, and the Max chipping width 206 from the kerf end), the determination unit 43 determines that the allowable value has not been exceeded if the check item is equal to or less than the allowable value, and determines that the allowable value has been exceeded if the check item is greater than the allowable value. Furthermore, for check items that specify the minimum allowable value (in this embodiment, the kerf width Min 204), the determination unit 43 determines that the allowable value has not been exceeded if the check item is equal to or more than the allowable value, and determines that the allowable value has been exceeded if the check item is smaller than the allowable value.

[0051] When the detection value detected by the image processing unit 42 for a check item in a kerf check does not exceed the allowable value, the judgment unit 43 judges that the check item in the kerf check is normal. Also, when the detection value detected by the image processing unit 42 for a check item in a kerf check exceeds the allowable value, the judgment unit 43 judges that an abnormality has occurred in the check item in the kerf check.

[0052] 7 and 8, the image processing unit 42 arranges the captured images 401, 402 in which the mask setting unit 44 has set the inner mask 411 and the pair of outer masks 412, the width 421 of the inner mask 411 and the separation width 422 of the pair of outer masks 412 calculated by the mask setting unit 44 with reference to the mask setting data 350, the plurality of check items in the kerf check and their allowable values ​​stored in the storage unit 41 as condition data 300, and the detection values ​​of the plurality of check items in the kerf check detected by the image processing unit 42, and generates result display screens 501, 502 by attaching a conspicuous display to the column of the check item determined by the determination unit 43 to have an abnormality, and causes the display unit 51 of the notification unit 50 to display the result display screens 501, 502 including information on the result determined by the determination unit 43 in this manner. In the example shown in Fig. 7, the display unit 51 notifies that the cutting groove 200 is normal since all the check items are normal, and in the example shown in Fig. 8, it notifies that the cutting groove 200 is abnormal since an abnormality has occurred in the chipping width 205 from the kerf center 201. Note that the conspicuous display added to the column of the check item determined to be abnormal is a conspicuous highlight display in a column displaying the allowable value and detection value of the check item in the example shown in Fig. 8, but the present invention is not limited to this, and any display that can be visually recognized by an operator at a glance may be used, such as changing the type, color, size, etc. of the font displaying the check item, the allowable value, the detection value, etc. to make it conspicuous, or blinking the display.

[0053] In addition, when the cutting groove 200 is normal because all check items are normal, the light-emitting unit 52 of the alarm unit 50 lights up, for example, blue or green, and when the cutting groove 200 is abnormal because at least one check item is abnormal, the light-emitting unit 52 flashes, for example, a conspicuous red light, to notify the operator, etc. of the result determined by the determination section 43.

[0054] In the cutting device 1 according to the embodiment having the above configuration, the mask setting unit 44 automatically calculates and sets the region (width 421) of the inner mask 411 to be set on the inside in the width direction of both banks (edges) 210 of the cutting groove 200 in accordance with the blade thickness 21-2 of the cutting blade 21, and calculates and sets the region (separation width 422) of a pair of outer masks 412 to be set on the outside in the width direction of both banks (edges) 210 of the cutting groove 200. That is, the cutting device 1 according to the embodiment automatically changes the mask setting according to the blade thickness 21-2 of the cutting blade 21. Therefore, the cutting device 1 according to the embodiment has an effect of suppressing erroneous detection of the cutting groove 200 due to forgetting to change the mask setting corresponding to the blade thickness 21-2 of the cutting blade 21.

[0055] It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. [Explanation of symbols]

[0056] 1 Cutting equipment 10 Chuck table 20 Cutting unit 21 Cutting blade 21-2 Blade thickness 22 Spindle 30 Imaging unit 41 Storage section 42 Image processing section 43 Judgment section 44 Mask setting section 50 Notification Unit 100 Workpiece 200 cutting groove 210 Edge 220 edge 411 Inner Mask 412 Outer Mask

Claims

1. A cutting device including a chuck table for holding a workpiece, and a cutting unit for forming a cutting groove in the workpiece held on the chuck table with a cutting blade attached to a spindle, an imaging unit for capturing an image of the cut groove formed in the workpiece during processing; A memory unit that stores cutting conditions for cutting a workpiece, check items for checking the quality of the cut groove and allowable values ​​for the check items, and information on the blade thickness of the cutting blade; an image processing unit that detects the cutting groove from the captured image; a determination unit that determines whether or not each of the plurality of check items exceeds the allowable value based on the cutting groove detected by the image processing unit; a notification unit that notifies the result of the determination by the determination unit, the image processing unit has a mask setting unit that, when detecting the cutting groove from the captured image, masks an area inside or outside both banks of the cutting groove as an area outside the detection target of the cutting groove, The cutting device is characterized in that the mask setting unit calculates and sets the area in accordance with the cutting blade thickness stored in the memory unit.

2. The memory unit further stores a difference between the blade thickness of the cutting blade and the width of the inner region, 2. The cutting device according to claim 1, wherein the mask setting unit calculates the width based on the blade thickness of the cutting blade and the difference, and sets the inner region.

Images