Diagnostic method for cutting blade, cutting method, and processing apparatus

Abstract

To provide a diagnostic method for a cutting blade capable of appropriately diagnosing the condition of the cutting blade.SOLUTION: A diagnostic method for a cutting blade that diagnoses the condition of the cutting blade, comprises: a positioning step of positioning a tip region of the cutting blade between a light emitting unit that emits light and a light receiving unit that receives the light emitted from the light emitting unit; a chip calculation step of emitting the light from the light emitting unit toward the light receiving unit after the positioning step, and calculating the size and number of chips present in part or whole of the tip region of the cutting blade on the basis of the received light amount of the light receiving unit; and a diagnostic step of diagnosing the condition of the cutting blade on the basis of the size and number of chips calculated in the chip calculation step.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a method for diagnosing a cutting blade, a cutting method, and a processing apparatus.

Background Art

[0002] In the manufacturing process of device chips used in electronic devices such as mobile phones and personal computers (PCs), for example, wafers made of silicon are used. A plurality of dividing planned lines (streets) are set in a grid pattern on the front surface side of the wafer. Devices such as integrated circuits (ICs) are formed in each of a plurality of regions partitioned by the plurality of dividing planned lines. The wafer is thinned to a predetermined thickness by grinding the back surface side thereof with a grinding apparatus or the like. Then, the wafer is divided into individual device chips by cutting along the dividing planned lines with a cutting blade mounted on a cutting apparatus (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, when machining a workpiece such as a wafer with a cutting blade, a load is applied to the tip region (cutting edge) of the cutting blade that contacts the workpiece, and chipping may occur. If the workpiece is machined with a chipped cutting blade, there is a risk of poor machining of the workpiece or damage to the cutting blade. Therefore, in order to prevent poor machining of the workpiece and damage to the cutting blade, it is necessary to timely detect the chipping that has occurred in the tip region of the cutting blade. Thus, a diagnosis may be performed to check whether chipping has occurred in the cutting blade before, after, or during the cutting of the workpiece.

[0005] In the above diagnosis, for example, an allowable range of the size of chipping that does not adversely affect the cutting of the workpiece is set in advance, and it is determined whether the size of the chipping formed on the cutting blade is within the allowable range. However, even if the size of the chipping that has occurred on the cutting blade is within the allowable range, if the density of the chipping is high or the range in which the chipping is formed is wide, the possibility of adversely affecting the cutting of the workpiece increases. As a result, even though the cutting blade is diagnosed as normal, there is a risk of poor machining or damage to the cutting blade.

[0006] In view of the above circumstances, the present invention aims to provide a method for diagnosing a cutting blade, a cutting method, and a processing apparatus capable of appropriately diagnosing the state of the cutting blade.

Means for Solving the Problems

[0007] According to one aspect of the present invention, there is provided a method for diagnosing a cutting blade for diagnosing the state of a cutting blade, the method including: a positioning step of positioning a tip region of the cutting blade between a light projecting unit that irradiates light and a light receiving unit that receives the light irradiated from the light projecting unit; after the positioning step, irradiating the light from the light projecting unit toward the light receiving unit, and calculating a size and number of chips present in part or all of the tip region of the cutting blade based on the amount of light received by the light receiving unit; and a diagnosing step of diagnosing the state of the cutting blade based on the size and number of chips calculated in the chip calculating step.

[0008] Preferably, the size of the chip is the length or width of the chip.

[0009] Preferably, in the chip calculating step, the number of chips for each size of the chip is calculated, and in the diagnosing step, the state of the cutting blade is diagnosed by comparing the number of chips for each size of the chip with a reference value of the number of chips set for each size of the chip.

[0010] According to another aspect of the present invention, there is provided a cutting method for cutting a workpiece, the method including: a holding step of holding the workpiece by a holding table; after the holding step, a cutting step of cutting the workpiece by causing the cutting blade to penetrate the workpiece by relatively moving the cutting blade and the holding table while rotating the cutting blade; a positioning step of positioning a tip region of the cutting blade between a light projecting unit that irradiates light and a light receiving unit that receives the light irradiated from the light projecting unit; after the positioning step, irradiating the light from the light projecting unit toward the light receiving unit, and calculating a size and number of chips present in part or all of the cutting blade based on the amount of light received by the light receiving unit; and a diagnosing step of diagnosing the state of the cutting blade based on the size and number of chips calculated in the chip calculating step.

[0011] Preferably, the size of the chip is the length or width of the chip.

[0012] Preferably, in the chip calculation step, the number for each chip size is calculated, and in the diagnosis step, the state of the cutting blade is diagnosed by comparing the number for each chip size with the reference value of the number of chips set for each chip size.

[0013] Further, according to another aspect of the present invention, there is provided a processing apparatus for processing a workpiece, including a spindle to which a cutting blade for cutting the workpiece is attached, a light projecting unit for irradiating light, and a light receiving unit for receiving the light irradiated from the light projecting unit, a blade tip detection unit having the light receiving unit, a processing device, and a storage device, and a controller capable of controlling the operations of the cutting blade and the blade tip detection unit according to a program stored in the storage device, wherein the controller executes, according to the program, a procedure of positioning a tip region of the cutting blade between the light projecting unit and the light receiving unit, a procedure of irradiating the light from the light projecting unit toward the light receiving unit and calculating a size and number of chips present in a part or all of the cutting blade based on a light reception amount of the light receiving unit, and a procedure of diagnosing a state of the cutting blade based on the calculated size and number of chips.

[0014] Preferably, the size of the chip is the length or width of the chip.

[0015] Preferably, the controller diagnoses the state of the cutting blade by calculating the number for each chip size and comparing the number for each chip size with the reference value of the number of chips set for each chip size.

Advantages of the Invention

[0016] According to the method for diagnosing a cutting blade according to one aspect of the present invention, the state of the cutting blade is diagnosed based on the size and number of chips present in a part or all of the tip region of the cutting blade. This makes it possible to determine whether to allow chips of the cutting blade in consideration of not only the size of the chips but also the chip density, the formation range, etc., and to appropriately diagnose the state of the cutting blade.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0018] Hereinafter, an embodiment according to an aspect of the present invention will be described with reference to the accompanying drawings. First, a configuration example of a processing apparatus according to this embodiment will be described. FIG. 1 is a perspective view showing a processing apparatus (cutting apparatus) 2 for cutting a workpiece 11. In FIG. 1, the direction along the X-axis (X-axis direction, machining feed direction, first horizontal direction, front-rear direction) and the direction along the Y-axis (Y-axis direction, indexing feed direction, second horizontal direction, left-right direction) are perpendicular to each other. Also, the direction along the Z-axis (Z-axis direction, up-down direction, height direction, vertical direction) is perpendicular to the X-axis direction and the Y-axis direction.

[0019] The workpiece 11 is a member to be subjected to cutting processing by the processing apparatus 2. For example, the workpiece 11 is a disk-shaped wafer made of a semiconductor material such as single-crystal silicon, and has surfaces (upper surface) 11a and back surfaces (lower surface) 11b that are generally parallel to each other.

[0020] The surface 11a of the workpiece 11 is partitioned into a plurality of rectangular regions by streets (division planned lines) arranged in a grid pattern so as to intersect each other. Also, devices such as IC (Integrated Circuit), LSI (Large Scale Integration), LED (Light Emitting Diode), and MEMS (Micro Electro Mechanical Systems) devices are formed in each of the plurality of regions partitioned by the streets. By dividing the workpiece 11 along the streets with the processing apparatus 2, a plurality of chips (device chips) each having a device are manufactured.

[0021] However, there are no restrictions on the material, shape, structure, size, etc. of the workpiece 11. For example, the workpiece 11 may be a wafer (substrate) of any shape made of a semiconductor other than silicon (GaAs, InP, GaN, SiC, etc.), glass, ceramics, resin, metal, etc. Also, there are no restrictions on the type, quantity, shape, structure, size, arrangement, etc. of the devices formed on the workpiece 11, and the workpiece 11 may not have any devices formed thereon.

[0022] Furthermore, the workpiece 11 may be a package substrate such as a CSP (Chip Size Package) substrate or a QFN (Quad Flat Non-leaded package) substrate. For example, the package substrate is formed by mounting a plurality of device chips on a predetermined substrate and coating and sealing the mounted device chips with a resin layer (mold resin). By cutting and dividing the package substrate with the processing apparatus 2, a plurality of chips (package devices) each including a plurality of packaged device chips are manufactured.

[0023] When processing the workpiece 11 with the processing apparatus 2, for the convenience of handling (conveying, holding, etc.) the workpiece 11, the workpiece 11 is supported by the frame 13. For example, the frame 13 is an annular member made of a metal such as SUS (stainless steel), and a circular opening penetrating the frame 13 in the thickness direction is provided at the center of the frame 13. Note that the diameter of the opening of the frame 13 is larger than the diameter of the workpiece 11.

[0024] A circular film 15 is fixed to the workpiece 11 and the frame 13. For example, as the film 15, a tape including a circularly formed base material and an adhesive layer (paste layer) provided on the base material is used. However, the film 15 may be a thermocompression bonding film that does not include an adhesive layer and can be thermocompression bonded to the workpiece 11 and the frame 13.

[0025] With the workpiece 11 disposed inside the opening of the frame 13, the central portion of the film 15 is attached to the back surface 11b side of the workpiece 11, and the outer peripheral portion of the film 15 is attached to the frame 13. Thereby, the workpiece 11 is supported by the frame 13 via the film 15.

[0026] The processing device 2 includes a base 4 that supports or houses each component constituting the processing device 2. On the upper surface of the base 4, a moving unit (moving mechanism) 6 is installed. The moving unit 6 includes a pair of X-axis guide rails 8 arranged along the X-axis direction. A flat X-axis moving table 10 is slidably mounted on the pair of X-axis guide rails 8 along the X-axis guide rails 8.

[0027] On the lower surface (back surface) side of the X-axis moving table 10, a nut portion (not shown) is provided. An X-axis ball screw 12 arranged along the X-axis direction between the pair of X-axis guide rails 8 is screwed into this nut portion. Further, an X-axis pulse motor 14 is connected to an end of the X-axis ball screw 12. When the X-axis ball screw 12 is rotated by the X-axis pulse motor 14, the X-axis moving table 10 moves in the X-axis direction along the X-axis guide rails 8.

[0028] On the upper surface (front surface) of the X-axis moving table 10, a columnar table base 16 is installed. On the upper part of the table base 16, a chuck table (holding table) 18 for holding the workpiece 11 is mounted.

[0029] The upper surface of the chuck table 18 is a flat surface substantially parallel to the horizontal direction (XY plane direction), and constitutes a circular holding surface 18a for holding the workpiece 11. The holding surface 18a is connected to a suction source (not shown) such as an ejector via a flow path (not shown), a valve (not shown), etc. formed inside the chuck table 18. Further, the chuck table 18 includes a plurality of clamps 18b for gripping and fixing a frame 13 that supports the workpiece 11. The plurality of clamps 18b are arranged at substantially equal intervals along the circumferential direction of the holding surface 18a around the holding surface 18a.

[0030] By operating the moving unit 6 and moving the X-axis moving table 10 along the X-axis guide rail 8, the chuck table 18 moves along the X-axis direction. Further, a rotation drive source (not shown) such as a motor for rotating the chuck table 18 around a rotation axis substantially parallel to the Z-axis direction is connected to the chuck table 18.

[0031] A water case 20 for temporarily storing waste liquid generated during the operation of the processing device 2 is provided around the moving unit 6. For example, the used processing liquid used for processing the workpiece 11 and the used cleaning liquid used for cleaning the workpiece 11 are stored as waste liquid inside the water case 20. The waste liquid stored in the water case 20 is discharged to the outside of the processing device 2 through a drain (not shown) or the like at a predetermined timing.

[0032] Also, a gantry support structure 22 is installed on the upper surface side of the base 4 so as to straddle the moving unit 6. A pair of moving units (moving mechanisms) 24 are installed at both ends on the front (surface) side of the support structure 22.

[0033] Specifically, a pair of Y-axis guide rails 26 are fixed along the Y-axis direction on the front side of the support structure 22. Flat plate-shaped Y-axis moving plates 28 provided in a pair of moving units 24 are slidably mounted along the Y-axis guide rails 26 on the pair of Y-axis guide rails 26. Further, a pair of Y-axis ball screws 30 are provided between the pair of Y-axis guide rails 26 along the Y-axis direction.

[0034] A nut portion (not shown) is provided on the rear (back) side of the Y-axis moving plate 28, and the Y-axis ball screw 30 is screwed into this nut portion. Further, a Y-axis pulse motor 32 is connected to the end of the Y-axis ball screw 30. When the Y-axis ball screw 30 is rotated by the Y-axis pulse motor 32, the Y-axis moving plate 28 moves in the Y-axis direction along the Y-axis guide rail 26.

[0035] On the front (surface) side of the Y-axis moving plate 28, a pair of Z-axis guide rails 34 are fixed along the Z-axis. A flat-plate-shaped Z-axis moving plate 36 is slidably mounted along the Z-axis guide rails 34 on the pair of Z-axis guide rails 34. Also, between the pair of Z-axis guide rails 34, a Z-axis ball screw 38 is provided along the Z-axis direction.

[0036] On the rear (back) side of the Z-axis moving plate 36, a nut portion (not shown) is provided, and the Z-axis ball screw 38 is screwed into this nut portion. Also, a Z-axis pulse motor 40 is connected to the end of the Z-axis ball screw 38. When the Z-axis ball screw 38 is rotated by the Z-axis pulse motor 40, the Z-axis moving plate 36 moves in the Z-axis direction along the Z-axis guide rails 34.

[0037] A processing unit (cutting unit) 42 is fixed to the lower part of the Z-axis moving plate 36. An annular cutting blade 70 for cutting the workpiece 11 is mounted on the processing unit 42. The processing unit 42 performs a cutting process on the workpiece 11 by causing the cutting blade 70 to cut into the workpiece 11 held by the chuck table 18. Details of the processing unit 42 and the cutting blade 70 will be described later (see FIGS. 2(A), 2(B) and 3).

[0038] An imaging unit 44 for imaging the workpiece 11 and the like held by the chuck table 18 is provided at a position adjacent to the processing unit 42. For example, the imaging unit 44 is constituted by a camera (visible light camera, infrared camera, etc.) including an optical microscope and an imaging element such as a CCD (Charged-Coupled Devices) sensor or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. By imaging the workpiece 11 held by the chuck table 18 with the imaging unit 44, an imaging image of the workpiece 11 is obtained. The imaging image is used for alignment between the workpiece 11 and the cutting blade 70 and evaluation of the workpiece 11.

[0039] When the moving unit 6 is actuated to move the X-axis moving table 10 along the X-axis direction, the chuck table 18, the machining unit 42, and the imaging unit 44 move relatively along the X-axis direction. Also, when the moving unit 24 is actuated to move the Y-axis moving plate 28 along the Y-axis direction, the chuck table 18, the machining unit 42, and the imaging unit 44 move relatively along the Y-axis direction. Further, when the moving unit 24 is actuated to move the Z-axis moving plate 36 along the Z-axis direction, the chuck table 18, the machining unit 42, and the imaging unit 44 move relatively (ascend and descend) along the Z-axis direction.

[0040] When cutting blades 70 are respectively mounted on the pair of machining units 42, the pair of cutting blades 70 are arranged to face each other. That is, the machining apparatus 2 is a so-called facing dual spindle type cutting apparatus. However, the number of machining units provided in the machining apparatus 2 may be one set.

[0041] On the front side of the machining apparatus 2, a display unit (display portion, display device) 46 is provided. The display unit 46 is composed of various displays and displays information (such as machining conditions, machining status, etc.) and operation screens related to the machining apparatus 2 or the workpiece 11. For example, a touch panel type display is used as the display unit 46. In this case, the display unit 46 also functions as an input unit (input portion, input device) for inputting information to the machining apparatus 2, and the operator can input information to the machining apparatus 2 by touch-operating the display unit 46. However, the input unit may be an electronic device (such as a mouse, a keyboard, a transceiver, etc.) provided independently of the display unit 46.

[0042] On the upper part of the processing device 2, a notification unit (notification section, notification device) 48 for notifying an operator of information is provided. For example, an indicator lamp (warning lamp) is installed as the notification unit 48, and when an abnormality occurs in the processing device 2 or the workpiece 11, the indicator lamp lights up or blinks to issue an error. However, there is no limitation on the type of the notification unit 48. For example, the notification unit 48 may be a speaker or the like that notifies the operator of information by sound or voice.

[0043] Furthermore, the processing device 2 includes a controller (control unit, control section, control device) 50 that controls the processing device 2. The controller 50 is connected to each component (moving unit 6, chuck table 18, moving unit 24, processing unit 42, imaging unit 44, display unit 46, notification unit 48, etc.) that constitutes the processing device 2.

[0044] The controller 50 controls the operations of the respective components by outputting control signals to the respective components of the processing device 2, and operates the processing device 2. For example, the controller 50 is constituted by a computer and includes a processing device 110 that executes processes such as calculations necessary for the operation of the processing device 2, and a storage device 120 that stores various types of information (data, programs, etc.) used for the operation of the processing device 2. The processing device 110 is constituted by a processor such as a CPU (Central Processing Unit), and the storage device 120 is constituted by a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The specific functions of the controller 50 will be described later (see FIG. 4).

[0045] Next, a configuration example of the processing unit 42 will be described. FIG. 2(A) is a perspective view showing the processing unit 42, and FIG. 2(B) is a partial cross-sectional side view showing the processing unit 42. In FIG. 2(B), for convenience of explanation, the illustration of a blade cover 82 described later is omitted.

[0046] The processing unit 42 includes a cylindrical housing 60. The housing 60 houses a cylindrical spindle 62 (see Fig. 2(B)) arranged along the Y-axis direction. The tip (one end side) of the spindle 62 protrudes from the housing 60. Also, a rotary drive source (not shown) such as a motor for rotating the spindle 62 is connected to the base end portion (the other end side) of the spindle 62.

[0047] A blade mount 64 (see Fig. 2(B)) is fixed to the tip of the spindle 62. The blade mount 64 is made of a metal such as an aluminum alloy and includes a disc-shaped flange portion 64a and a cylindrical support shaft (boss portion) 64b protruding from the central portion of the flange portion 64a. An annular cutting blade 70 for cutting the workpiece 11 is mounted on the blade mount 64.

[0048] Fig. 3 is a perspective view showing the cutting blade 70. The cutting blade 70 is a hub-type cutting blade (hub blade) including an annular hub base 72 and an annular cutting edge 74 provided along the outer peripheral edge of the hub base 72. In Fig. 3, for ease of viewing, the cutting edge 74 is patterned.

[0049] The hub base 72 is made of a metal such as an aluminum alloy and includes a first surface (front surface) 72a and a second surface (back surface) 72b. A circular through-hole 72c extending from the first surface 72a to the second surface 72b of the hub base 72 is provided so as to penetrate the hub base 72 in the thickness direction at the central portion of the hub base 72. Also, an annular convex portion 72d protruding from the first surface 72a of the hub base 72 is provided around the through-hole 72c. The convex portion 72d corresponds to the portion that is gripped when the cutting blade 70 is attached and detached.

[0050] On the side of the second surface 72b of the hub base 72, an annular cutting blade 74 is formed annularly along the outer peripheral edge of the hub base 72. The cutting blade 74 corresponds to a machining part that contacts the workpiece 11 and cuts the workpiece 11. Note that the outer diameter of the cutting blade 74 is larger than the outer diameter of the hub base 72. Therefore, the cutting blade 74 is arranged so as to protrude radially outward from the outer peripheral edge of the hub base 72.

[0051] As shown in FIG. 2(B), the cutting blade 70 is attached to the machining unit 42. Specifically, the cutting blade 70 is attached to the blade mount 64 such that the support shaft 64b is inserted into the through hole 72c (see FIG. 3). Further, a screw groove (not shown) is formed at the tip of the support shaft 64b, and a fixing nut 66 for fixing the cutting blade 70 is screwed into this screw groove. When the fixing nut 66 is tightened on the support shaft 64b with the cutting blade 70 attached to the blade mount 64, the cutting blade 70 is clamped by the flange portion 64a and the fixing nut 66.

[0052] In this way, the cutting blade 70 is attached to the tip of the spindle 62 via the blade mount 64. Then, when a rotation drive source (not shown) connected to the spindle 62 is operated, the cutting blade 70 rotates around a rotation axis substantially parallel to the Y-axis direction by the power transmitted from the rotation drive source via the spindle 62 and the blade mount 64.

[0053] Note that the cutting blade 70 may be a washer-type cutting blade (washer blade). In this case, the cutting blade 70 is composed only of an annular cutting blade having abrasive grains and a binder for fixing the abrasive grains made of metal, ceramics, resin, or the like.

[0054] A plate-shaped support member 80 is fixed to the tip of the housing 60. Further, a box-shaped blade cover 82 (see Fig. 2(A)) that covers the cutting blade 70 is attached to the surface side of the support member 80. A pair of first connection parts 84 are provided at one end of the blade cover 82, and a second connection part 88 and a third connection part 90 are provided at the other end of the blade cover 82. Pipes (not shown), such as pipes for supplying a liquid (processing liquid) such as pure water, are connected to the first connection part 84, the second connection part 88, and the third connection part 90, respectively.

[0055] A pair of nozzles (cooler nozzles) 86 that are arranged so as to sandwich the lower end of the cutting blade 70 are connected to the pair of first connection parts 84 (only one nozzle 86 is shown in Fig. 2(A)). Supply ports (not shown) that open toward the cutting blade 70 are provided in the pair of nozzles 86, respectively. When the processing liquid is supplied to the first connection part 84, the processing liquid flows into the pair of nozzles 86 and is supplied to the front and back surfaces of the cutting blade 70 from the supply ports of the pair of nozzles 86.

[0056] A nozzle (shower nozzle, not shown) provided inside the blade cover 82 is connected to the second connection part 88. The tip of the shower nozzle opens toward the outer peripheral edge of the cutting blade 70. When the processing liquid is supplied to the second connection part 88, the processing liquid flows into the shower nozzle, and the processing liquid is supplied from the tip of the shower nozzle to the outer peripheral edge of the cutting blade 70.

[0057] A pair of nozzles (spray nozzles) 92 that open downward are connected to the third connection part 90. When the processing liquid is supplied to the third connection part 90, the processing liquid flows into the nozzles 92, and the processing liquid is supplied from the tips of the nozzles 92 toward the holding surface 18a (see Fig. 1) of the chuck table 18.

[0058] When machining the workpiece 11, the workpiece 11 (see FIG. 1) is held by the chuck table 18, and while rotating the cutting blade 70, it is made to cut into the workpiece 11. Then, during the cutting of the workpiece 11, machining fluid is supplied to the workpiece 11 and the cutting blade 70 from the nozzle 86, the shower nozzle (not shown), and the nozzle 92. As a result, the workpiece 11 and the cutting blade 70 are cooled, and the chips (machining debris) generated by the cutting of the workpiece 11 are washed away.

[0059] On the upper part of the blade cover 82, a monitoring unit 94 for monitoring the state of the cutting blade 70 mounted on the machining unit 42 is provided. As shown in FIG. 2(B), for example, the monitoring unit 94 includes a rectangular parallelepiped-shaped frame 96. Inside the frame 96, a housing portion 96a that opens on the lower surface side of the frame 96 is provided. The housing portion 96a houses a detection unit 98 that detects the tip portion (outer peripheral portion) of the cutting blade 70.

[0060] Further, the monitoring unit 94 includes a ball screw 100 connected to the detection unit 98. The ball screw 100 is arranged along the Z-axis direction so as to penetrate the frame 96, and a pulse motor 102 is connected to the end of the ball screw 100. The detection unit 98 includes a nut portion (not shown), and the ball screw 100 is screwed into this nut portion. When the ball screw 100 is rotated by the pulse motor 102, the detection unit 98 moves (ascends and descends) along the Z-axis direction. As a result, the height position (position in the Z-axis direction) of the detection unit 98 is adjusted.

[0061] FIG. 4 is a schematic diagram showing the controller 50 and the detection unit 98. FIG. 4 shows a block indicating the functional configuration of the controller 50 and a schematic diagram of the display unit 46, the notification unit 48, and the detection unit 98.

[0062] The detection unit 98 is an optical sensor that detects the tip of the cutting blade 70 and includes a detection unit 104. The detection unit 104 includes a rectangular parallelepiped-shaped base 104a, a light projecting unit 104b that protrudes downward from the base 104a, and a light receiving unit 104c. The light projecting unit 104b and the light receiving unit 104c are arranged so as to be separated in the Y-axis direction and face each other. The space between the light projecting unit 104b and the light receiving unit 104c corresponds to a blade insertion portion 104d into which the tip (cutting edge 74) of the cutting blade 70 is inserted.

[0063] A light source 106 such as an LED that emits light is connected to the light projecting unit 104b. The light emitted by the light source 106 is guided to the light projecting unit 104b via an optical fiber or the like and is irradiated from the light projecting unit 104b toward the light receiving unit 104c. The light irradiated from the light projecting unit 104b reaches the light receiving surface of the light receiving unit 104c and is received by the light receiving unit 104c.

[0064] A photoelectric conversion unit 108 that generates a signal (light reception amount signal) corresponding to the amount of light (light reception amount) received by the light receiving unit 104c is connected to the light receiving unit 104c. The photoelectric conversion unit 108 includes a photoelectric conversion element that converts light into an electrical signal (voltage). The light received by the light receiving unit 104c is guided to the photoelectric conversion unit 108 via an optical fiber or the like and is converted into an electrical signal by the photoelectric conversion unit 108. Thereby, a light reception amount signal corresponding to the light reception amount of the light receiving unit 104c is generated. The light reception amount signal generated by the photoelectric conversion unit 108 is output to the controller 50.

[0065] When machining the workpiece 11 with the machining apparatus 2 configured as described above (see FIG. 1), the workpiece 11 is held by the chuck table 18, and the cutting blade 70 mounted on the machining unit 42 is rotated while being cut into the workpiece 11. Thereby, a predetermined cutting process is performed on the workpiece 11.

[0066] When the workpiece 11 is cut with the cutting blade 70, a load is applied to the cutting blade 70, and chipping may occur in the tip region of the cutting blade 70. FIG. 5(A) is a front view of the cutting blade 70, and FIGS. 5(B), 5(C), and 5(D) are enlarged views of the tip region A of the cutting blade 70 in FIG. 5(A). The tip region A is a region including the cutting edge (outer circumference) 70a of the cutting edge 74. In FIG. 5(A), for the sake of clarity of the drawing, the cutting edge 74 is patterned as in FIG. 3.

[0067] FIG. 5(B) shows the cutting edge 70a without chipping. When using a cutting blade 70 without damage such as chipping on the cutting edge 70a, the workpiece 11 can be cut appropriately.

[0068] Also, FIG. 5(C) shows the cutting edge 70a with a relatively small chip 76a. In FIG. 5(C), a represents the length (depth) of the chip 76a, and b represents the width of the chip 76a. Further, FIG. 5(D) schematically shows the cutting edge 70a with a relatively large chip 76b. In FIG. 5(D), c represents the length (depth) of the chip 76b, and d represents the width of the chip 76b.

[0069] Here, the definitions of the length and width of the chip in this embodiment will be described taking the chip 76a as an example. The length of the chip 76a refers to the distance between both ends of the chip 76a in the direction along the radial direction of the cutting blade 70. For example, first, a virtual circle corresponding to the cutting edge 70a when there is no chip is set as a reference line. Then, the shortest distance from the point on the chip 76a closest to the center of the cutting blade 70 to the reference line corresponds to the length of the chip 76a. The width of the chip refers to the distance between two ends of the chip 76a at the tip of the cutting edge 70a. The length and width of the chip 76b are also defined in the same manner as the length and width of the chip 76a.

[0070] In this embodiment, the size (length and width) and number of chips 76a and 76b generated on the cutting edge 70a of the cutting blade 70 have important significance. For example, when the size of the chip exceeds a predetermined threshold value (reference value), if the area where the chip of the cutting blade 70 occurs comes into contact with the workpiece 11, an abnormal load may suddenly be applied to the workpiece 11, causing a decrease in machining accuracy and damage to the workpiece 11. In addition, with a large chip on the cutting blade 70 as a trigger, the cutting blade 70 is also likely to be damaged.

[0071] On the other hand, even when the size of the chip is below a predetermined threshold value and a single chip is unlikely to have an adverse effect on the workpiece 11 or the cutting blade 70, if the number of chips exceeds a predetermined threshold value, an abnormal load continuously acts between the workpiece 11 and the cutting blade 70, and there is still a risk of poor machining of the workpiece 11 and damage to the cutting blade 70.

[0072] Therefore, in this embodiment, the state of the cutting blade 70 is diagnosed using the controller 50 and the detection unit 98 (see FIG. 4). Specifically, the controller 50 controls the detection unit 98 to identify the size and number of chips generated on the cutting edge 70a of the cutting blade 70, and diagnoses the state of the cutting blade 70 based on the size and number of chips. This can avoid the continued cutting of the workpiece 11 in a state where the cutting blade 70 has chips of abnormal size or number, and avoid machining defects and damage to the cutting blade 70.

[0073] Hereinafter, a specific example of the cutting method according to this embodiment will be described. FIG. 6 is a flowchart showing the cutting method of the workpiece 11. In this embodiment, in the holding step S1, the workpiece 11 is held by the chuck table 18, and after the workpiece 11 is cut by the cutting blade 70 in the cutting step S2, the positioning step S3, the chip detection step S4, and the diagnosis step S5 are sequentially executed to diagnose the state of the cutting blade 70. Note that the positioning step S3, the chip detection step S4, and the diagnosis step S5 correspond to the diagnosis method of the cutting blade according to this embodiment.

[0074] In the holding step S1, the workpiece 11 is held by the chuck table 18 (see FIG. 1). Specifically, first, a conveying unit (not shown) conveys the workpiece 11 to the chuck table 18, and the workpiece 11 is placed on the holding surface 18a via the film 15. Also, the frame 13 is fixed by a plurality of clamps 18b. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 18a, the workpiece 11 is suction-held by the chuck table 18 via the film 15.

[0075] In the cutting step S2, while rotating the cutting blade 70, the cutting blade 70 and the chuck table 18 are relatively moved, so that the cutting blade 70 cuts into the workpiece 11 and the workpiece 11 is cut. A specific example of the cutting process in the cutting step S2 will be described with reference to FIG. 1.

[0076] First, the rotation angle of the chuck table 18 is adjusted so that the length direction of a predetermined street set on the workpiece 11 is along the X-axis direction. Also, the position of the machining unit 42 in the Z-axis direction is adjusted by the moving unit 24 so that the lower end of the cutting blade 70 is positioned below the back surface (lower surface) 11b of the workpiece 11. Further, the position of the machining unit 42 in the Y-axis direction is adjusted by the moving unit 24 so that the cutting blade 70 is positioned on the extension line of a predetermined street.

[0077] Then, while rotating the cutting blade 70, the chuck table 18 is moved along the X-axis direction by the moving unit 6. As a result, the chuck table 18 and the cutting blade 70 relatively move along the X-axis direction. As a result, the cutting blade 70 cuts into the workpiece 11 along a predetermined street, and the workpiece 11 is cut and divided (full cut). As described above, the machining fluid is supplied to the workpiece 11 and the cutting blade 70 during the cutting of the workpiece 11.

[0078] Thereafter, by repeating the same procedure, the workpiece 11 is cut and divided along other streets. When the workpiece 11 is cut along all the streets, the workpiece 11 is divided into a plurality of chips.

[0079] However, the content of the processing in the cutting step S2 is not limited to the above. For example, by cutting the workpiece 11 with the cutting blade 70, a groove having a depth less than the thickness of the workpiece 11 can be formed on the surface (upper surface) 11a side of the workpiece 11 (half cut). In this case, the height position of the processing unit 42 is adjusted so that the lower end of the cutting blade 70 is positioned below the surface (upper surface) 11a of the workpiece 11 and above the back surface (lower surface) 11b of the workpiece 11. In this state, by cutting the cutting blade 70 into the workpiece 11, a groove is formed in the workpiece 11 along the street.

[0080] After grooves are formed along all the streets, when the back surface side of the workpiece 11 is ground to thin the workpiece 11 and the grooves are exposed on the back surface 11b of the workpiece 11, the workpiece 11 is divided into a plurality of chips along the streets. Thus, the method of dividing the workpiece 11 by performing grinding after cutting is called a DBG (Dicing Before Grinding) process.

[0081] Next, the tip region of the cutting blade 70 is positioned between the light projecting unit 104b and the light receiving unit 104c of the detection unit 98 (see FIG. 4) (positioning step S3). In the positioning step S3, with the cutting blade 70 mounted on the processing unit 42, the height position of the detection unit 98 is adjusted. Specifically, the ball screw 100 (see FIG. 2(B)) is rotated by the pulse motor 102 to move the detection unit 98 up and down along the Z-axis direction, so that the tip region (upper end portion) of the cutting blade 70 is inserted into the blade insertion portion 104d (see FIG. 4). Thereby, the tip region of the cutting blade 70 is positioned between the light projecting unit 104b and the light receiving unit 104c.

[0082] However, there is no limitation on the timing when the positioning step S3 is performed. For example, after the cutting blade 70 is attached to the processing unit 42 (see FIGS. 2(A) and 2(B)), before the workpiece 11 is held by the chuck table 18 (before the execution of the holding step S1), or before the cutting of the workpiece 11 is started (before the execution of the cutting step S2), the positioning step S3 may be performed.

[0083] Next, the size and number of chippings in part or all of the tip region of the cutting blade 70 are calculated (chipping detection step S4), and the state of the cutting blade 70 is diagnosed based on the size and number of chippings (diagnosis step S5). The chipping detection step S4 and the diagnosis step S5 are performed by the controller 50 and the detection unit 98 (see FIG. 4).

[0084] As shown in FIG. 4, the controller 50 includes a processing device 110 that executes various processes necessary for diagnosing the state of the cutting blade 70, and a storage device 120 that stores information (data, programs, etc.) used for the processes by the processing device 110 and information obtained by the processes by the processing device 110.

[0085] Further, the processing device 110 includes a chipping detection unit 112 that calculates the size and number of chippings existing in part or all of the tip region of the cutting blade 70 based on the light reception amount of the light receiving unit 104c of the detection unit 98, a diagnosis unit 114 that diagnoses whether the cutting blade 70 is in a state where it can appropriately cut the workpiece 11 based on the size and number of chippings existing in the tip region of the cutting blade 70 specified by the chipping detection unit 112, and a notification control unit 116 that controls the notification of the diagnosis result by the diagnosis unit 114.

[0086] In the chipping detection step S4, with the tip region (upper end portion) of the cutting blade 70 positioned between the light projecting unit 104b and the light receiving unit 104c, the cutting blade 70 is rotated at a predetermined speed. Further, the controller 50 outputs a control signal to the light source 106 of the detection unit 98 to irradiate light from the light projecting unit 104b toward the light receiving unit 104c.

[0087] Part of the light irradiated from the light projection unit 104b reaches the light receiving unit 104c while being blocked by the tip of the cutting blade 70. Then, the light received by the light receiving unit 104c is converted into an electrical signal by the photoelectric conversion unit 108, and the photoelectric conversion unit 108 outputs a light reception amount signal corresponding to the light reception amount of the light receiving unit 104c to the controller 50.

[0088] For example, the photoelectric conversion unit 108 detects the light received by the light receiving unit 104c during the rotation of the cutting blade 70 multiple times at a predetermined period (sampling period), and generates a light reception amount signal for each predetermined rotation angle of the cutting blade 70. Further, the detection of light by the photoelectric conversion unit 108 continues until the cutting blade 70 rotates at least once.

[0089] Here, the size and number of chips existing in the tip region of the cutting blade 70 are reflected in the light reception amount of the light receiving unit 104c. Specifically, the light reception amount of the light receiving unit 104c changes according to the size and number of chips on the cutting blade 70, and the size and number of chips are also reflected in the light reception amount signal generated by the photoelectric conversion unit 108.

[0090] FIG. 7(A) is a graph showing the light reception amount of the light receiving unit 104c when detecting the tip region of the cutting blade 70 without chips, and FIG. 7(B) is a graph showing the light reception amount of the light receiving unit 104c when detecting the tip region of the cutting blade 70 with chips. FIGS. 7(A) and 7(B) show the light reception amount over the entire circumference of the cutting blade 70. When there are no chips on the cutting blade 70, the light traveling from the light projection unit 104b to the light receiving unit 104c is blocked to the same extent by the tip region of the cutting blade 70 over the entire circumference of the cutting blade 70. Therefore, as shown in FIG. 7(A), the light reception amount received by the light receiving unit 104c is substantially constant in the detection region.

[0091] On the other hand, when there is a chip in the tip region of the cutting blade 70, a part of the light irradiated from the light projecting unit 104b passes through the chip. Therefore, the amount of light irradiated to the portion of the cutting blade 70 where the chip exists and received by the light receiving unit 104c is larger than the amount of light irradiated to the portion of the cutting blade 70 where no chip exists and received by the light receiving unit 104c. As a result, as shown in FIG. 7(B), the chip existing in the tip region of the cutting blade 70 is reflected in the amount of light received by the light receiving unit 104c.

[0092] For example, when the amount of light received by the light receiving unit 104c is larger than a predetermined threshold value, it is determined that a chip exists. The threshold value of the amount of light received is set based on, for example, the amount of light received by the light receiving unit 104c when the tip portion of the cutting blade 70 without a chip is detected by the detection unit 104.

[0093] Also, in a graph showing the relationship between the amount of light received and the rotation angle over the entire circumference of the cutting blade 70 (see FIG. 7(B)), for example, the lowest value of the amount of light received is set as a reference line (baseline). Then, a portion where the amount of light received protrudes from the baseline by a predetermined magnitude can be determined as a portion where a chip exists.

[0094] FIG. 7(B) shows two relatively high peaks 130 and 132 and two relatively low peaks 134 and 136. The chip existing at the tip of the cutting blade 70 is reflected in the transition of the amount of light received as a local peak. Therefore, for example, when there are two relatively long chips and two relatively short chips in the cutting blade 70, peaks 130 and 132 and peaks 134 and 136 appear in the transition of the amount of light received. In this way, the larger the length of the chip, the larger the amount of light received by the light receiving unit 104c. Also, the number of local peaks is reflected in the transition of the amount of light received as the number of chips.

[0095] Note that the cutting blade 70 is mounted such that its center coincides with the rotation axis of the spindle 62 (see Fig. 2(B)). However, due to mounting errors during the mounting of the cutting blade 70 or displacement of the cutting blade 70 during cutting of the workpiece 11, the center of the cutting blade 70 may deviate slightly from the center of the spindle 62. In this case, the distance from the rotation center of the cutting blade 70 to the cutting edge 70a of the cutting blade 70 is not constant, and the cutting blade 70 is in an eccentric state.

[0096] Fig. 8(A) is a graph showing the amount of light received by the light receiving portion 104c when detecting the tip region of the eccentric cutting blade 70 without chipping. Figs. 8(B) and 8(C) are graphs showing the amount of light received by the light receiving portion 104c when detecting the tip region of the eccentric cutting blade 70 with chipping. When the cutting blade 70 is eccentric, the upper end position of the cutting blade 70 varies as the cutting blade 70 rotates, and the amount of light received by the light receiving portion 104c changes in a periodic curve. As a result, as shown in Figs. 8(A) to 8(C), undulations occur in the change of the amount of light received. However, even when the cutting blade 70 is in an eccentric state, peaks reflecting the chipping present in the tip region of the cutting blade 70 appear in the change of the amount of light received.

[0097] In Fig. 8(B), two relatively high peaks 130, 132 and two relatively low peaks 134, 136 are shown. In Fig. 8(C), four peaks with different heights are shown. Specifically, a peak 138 having a width corresponding to a rotation angle of 7°, peaks 140, 142 having a width corresponding to a rotation angle of 2°, and a peak 144 having a width corresponding to a rotation angle of 4° are shown.

[0098] As described above, the size and number of chips present in the tip region of the cutting blade 70 are reflected in the transition of the amount of light received by the light receiving unit 104c. Then, by detecting the amount of light received by the light receiving unit 104c a plurality of times at a predetermined sampling period while the cutting blade 70 rotates by a predetermined angle, a light reception amount signal corresponding to the entire tip region of the cutting blade 70 is acquired. The light reception amount signal thus acquired is input from the photoelectric conversion unit 108 to the chip detection unit 112 of the processing device 110 (see FIG. 4).

[0099] The chip detection unit 112 calculates the size and number of chips present in the entire tip region of the cutting blade 70 based on the light reception amount signal. For example, the chip detection unit 112 that has received the light reception amount signal extracts the peaks (see FIGS. 7(B), 8(B), and 8(C)) that appear in the transition of the light reception amount, and calculates the height and width of each peak. The height and width of the peak respectively correspond to the length and width of the chip present in the tip region of the cutting blade 70. Therefore, the chip detection unit 112 specifies the height and width of the peak as the length and width of the chip present in the tip region of the cutting blade 70, respectively. Note that the chip detection unit 112 may convert the height and width of the peak into the actual dimensions of the length and width of the chip of the cutting blade 70, and specify the converted value as the length and width of the chip of the cutting blade 70.

[0100] In addition, the chip detection unit 112 calculates the number of chips for each chip size. Specifically, the number of peaks that appear in the transition of the light reception amount corresponds to the number of chips. Therefore, the chip detection unit 112 counts the number of peaks and calculates the number of chips. Further, the detection unit 112 classifies the chips into a plurality of classes based on the size or width of the chips, and specifies the number of chips for each of the plurality of classes.

[0101] For example, the chip detection unit 112 classifies chips into classes with the chip length delimited within a predetermined range, such as a class with a chip length of 50 μm or more and less than 100 μm, a class with a chip length of 100 μm or more and less than 200 μm. Then, the calculated number of chips is counted as the number of each class according to the chip length. Similarly, the chip detection unit 112 classifies chips into classes with the chip width delimited within a predetermined range. Then, the calculated number of chips is counted as the number of each class according to the chip width.

[0102] In the above description, the case of detecting chips existing in the entire (entire circumference) tip region of the cutting blade 70 has been explained. However, in the chip detection step S4, chips existing in a part of the tip region of the cutting blade 70 may be detected. In this case, the detection of the light reception amount of the light receiving unit 104c is stopped after the cutting blade 70 rotates by a predetermined angle (before one rotation), and the chips existing in a partial range of the tip region of the cutting blade 70 are detected by the chip detection unit 112.

[0103] Also, in the above description, an example of detecting the light reception amount of the light receiving unit 104c multiple times while rotating the cutting blade 70 has been explained. However, the detection procedure of the light reception amount is not limited to this. For example, a light reception amount signal may be acquired by alternately repeating a process of rotating the cutting blade 70 by a predetermined angle and then stopping it, and a process of detecting the light reception amount of the light receiving unit 104c in a state where the cutting blade 70 is stopped (not rotating) multiple times.

[0104] Next, the controller 50 diagnoses the state of the cutting blade 70 based on the size and number of chips existing in the tip region of the cutting blade 70 detected in the chip detection step S4 (diagnosis step S5). In the diagnosis step S5, the diagnosis unit 114 determines the state of the cutting blade 70 based on the size and number of chips detected by the chip detection unit 112.

[0105] The number of chips for each size calculated by the chip detection unit 112 is input to the diagnosis unit 114. The storage device 120 includes a threshold storage unit 122 that stores the threshold value of the number of chips for each size. The threshold value of the number of chips is preset before the implementation of the diagnosis step S5 and is stored in the threshold storage unit 122. Then, the diagnosis unit 114 diagnoses whether the cutting blade 70 is in a suitable state for cutting the workpiece 11 by comparing the number of chips for each size counted by the chip detection unit 112 with the threshold value of the size of the chips stored in the threshold storage unit 122. Specifically, the diagnosis unit 114 determines whether the number of chips calculated by the chip detection unit 112 exceeds the threshold value.

[0106] FIG. 9(A) is a table showing an example of the threshold value of the number of chips set for each length of the chips stored in the threshold storage unit 122. FIG. 9(B) is a table showing an example of the threshold value of the number of chips set for each width of the chips stored in the threshold storage unit 122. As shown in FIGS. 9(A) and 9(B), the threshold value of the number of chips can be set to vary depending on the length and width of the chips.

[0107] For example, as shown in FIG. 9(A), the threshold value of the number of chips having a length of 50 μm or more and less than 100 μm is 10, while the threshold value of the number of chips having a length of 900 μm or more and less than 1000 μm is 2. Then, the diagnosis unit 114 compares the number of chips with the threshold value for each range of the chip length. If the number of chips exceeds the threshold value in any comparison, even if the number of chips does not exceed the threshold value in other comparisons, it is determined that the cutting blade 70 is not in a suitable state for cutting the workpiece 11. For example, even if the number of chips having a length of 50 μm or more and less than 100 μm calculated by the chip detection unit 112 is 5, if the number of chips having a length of 900 μm or more and less than 1000 μm is 3, the diagnosis unit 114 determines that the cutting blade 70 is not in a suitable state for cutting the workpiece 11. Note that the threshold value of the number of chips for each length may be a value defined by the ratio (%) to the total number of chips.

[0108] Further, for example, as shown in FIG. 9(B), the threshold number of chips having a width corresponding to a rotation angle of 1° or more and less than 2° is 10, while the threshold number of chips having a width corresponding to a rotation angle of 9° or more and less than 10° is 5. Then, the diagnosis unit 114 compares the number of chips for each range of chip widths with the threshold value. If the number of chips exceeds the threshold value in any comparison, even if the number of chips does not exceed the threshold value in other comparisons, it is determined that the cutting blade 70 is not in a suitable state for cutting the workpiece 11. For example, even if the number of chips having a width corresponding to a rotation angle of 1° or more and less than 2° calculated by the chip detection unit 112 is 5, if the number of chips having a width corresponding to a rotation angle of 9° or more and less than 10° is 3, the diagnosis unit 114 determines that the cutting blade 70 is not in a suitable state for cutting the workpiece 11. Note that the threshold value of the number of chips for each chip width may be a value defined by the ratio (%) of the total number of chips.

[0109] Further, the diagnosis unit 114 may calculate the sum of the widths of the chips (total chip amount) calculated by the chip detection unit 112, and compare this total chip amount with a preset threshold value to determine whether the cutting blade 70 is in a suitable state for cutting the workpiece 11. Further, the diagnosis unit 114 may calculate the chip rate obtained by dividing the total chip amount by 360°, and compare this chip rate with a preset threshold value to determine whether the cutting blade 70 is in a suitable state for cutting the workpiece 11.

[0110] As described above, the diagnosis unit 114 determines whether the cutting blade 70 is in a suitable state for cutting the workpiece 11 by using either or both of the threshold value of the number of chips determined for each chip length (FIG. 9(A)) or the threshold value of the number of chips determined for each chip width (FIG. 9(B)).

[0111] The result of the diagnosis by the diagnosis unit 114 is output to the notification control unit 116. When it is determined by the diagnosis unit 114 that the cutting blade 70 is not in a suitable state for cutting the workpiece 11, the notification control unit 116 causes the display unit 46 and the notification unit 48 to notify an error. Specifically, the notification control unit 116 outputs a control signal to the display unit 46, and causes the display unit 46 to display information (such as a message) prompting dressing or replacement of the cutting blade 70. Further, the notification control unit 116 outputs a control signal to the notification unit 48, and lights or blinks the notification unit 48. Thereby, the operator is notified that dressing or replacement of the cutting blade 70 is necessary.

[0112] As described above, by the method for diagnosing a cutting blade according to the present embodiment, it is diagnosed whether or not a chip has occurred on the cutting blade 70. When it is diagnosed in the diagnosis step S5 that the cutting blade 70 is not in a suitable state for cutting the workpiece 11, measures are taken as necessary to avoid cutting the workpiece 11 with the cutting blade 70 in a state where a chip has occurred.

[0113] For example, the operator who has received the above notification performs dressing by cutting the cutting blade 70 into a predetermined member (dressing board) to intentionally wear the tip of the cutting blade 70, thereby removing the chip existing in the tip region of the cutting blade 70 (chip removal step). The dressing board is formed by fixing abrasive grains such as green carborundum (GC) and white alumina (WA) with a binder such as a resin bond or a vitrified bond.

[0114] By dressing the cutting blade 70, the tip of the cutting blade 70 wears, and the chip existing at the tip of the cutting blade 70 is removed.

[0115] Also, when it is difficult to remove chips by dressing, the cutting blade 70 may be replaced (blade replacement step). Specifically, the cutting of the workpiece 11 by the cutting blade 70 is interrupted, and the cutting blade 70 in a state with chips is removed from the processing unit 42 (see FIGS. 2(A) and 2(B)). Then, a new cutting blade 70 without chips is attached to the processing unit 42, and the cutting of the workpiece 11 is resumed.

[0116] As described above, by sequentially performing the positioning step S3, the chip detection step S4, and the diagnosis step S5, the cutting blade diagnosis method according to the present embodiment is realized. And by performing the positioning step S3 to the diagnosis step S5 after the cutting step S2, the state of the cutting blade 70 after cutting the workpiece 11 can be diagnosed, and preparations can be made for machining the next workpiece.

[0117] However, the positioning step S3 to the diagnosis step S5 may be performed before the cutting step S2. For example, after the cutting blade 70 is attached to the processing unit 42 (see FIGS. 2(A) and 2(B)), the detection unit 98 is lifted to perform the positioning step S3. Then, before the cutting of the workpiece 11 by the cutting blade 70 is started, the chip detection step S4 and the diagnosis step S5 are performed. Thereby, the state of the cutting blade 70 can be finally confirmed immediately before the cutting of the workpiece 11.

[0118] Furthermore, the positioning step S3 to the diagnosis step S5 can also be performed during the execution of the cutting step S2. Specifically, during the cutting of the workpiece 11, the detection unit 98 is moved to position the tip of the cutting blade 70 between the light projecting unit 104b and the light receiving unit 104c (positioning step S3). Also, during the cutting of the workpiece 11, the outer peripheral portion of the rotating cutting blade 70 is detected by the detection unit 98, and a chip existing in the tip region of the cutting blade 70 is detected by the chip detection unit 112 (chip detection step S4). Further, during the cutting of the workpiece 11, the state of the cutting blade 70 is diagnosed by the diagnosis unit 114 (diagnosis step S5). By performing the positioning step S3 to the diagnosis step S5 during the cutting of the workpiece 11 in this manner, it becomes unnecessary to separately secure time for diagnosing the cutting blade 70, and the processing efficiency is improved.

[0119] The method for diagnosing a cutting blade according to the present embodiment is realized by controlling the operations of the respective components of the processing apparatus 2 with the controller 50 (see FIGS. 1 and 4). Specifically, in the storage device 120 (memory) of the controller 50, a program for causing the processing apparatus 2 to execute the holding step S1, the cutting step S2, the positioning step S3, the chip detection step S4, the diagnosis step S5, the notification step S6, the chip removal step, or the blade replacement step is stored. This program includes commands for causing the controller 50 to generate control signals output to the respective components of the processing apparatus 2 in order to realize each of the above steps.

[0120] When performing the processing of the workpiece 11 and the diagnosis of the cutting blade 70, the controller 50 reads out and executes the above program from the storage device 120. As a result, a series of processes corresponding to each of the above steps are executed by the controller 50, and control signals are sequentially output to the respective components of the processing apparatus 2. Thereby, each step included in the method for diagnosing a cutting blade according to the present embodiment is automatically performed.

[0121] As described above, in the cutting blade diagnosis method, cutting method, and processing apparatus according to the present embodiment, the state of the cutting blade 70 is diagnosed based on the size and number of chippings present in part or all of the tip region of the cutting blade 70. Thereby, it becomes possible to determine whether or not to allow chippings of the cutting blade 70 in consideration of not only the size of the chippings but also the density and formation range of the chippings, and the state of the cutting blade 70 can be appropriately diagnosed.

[0122] Note that the configuration of the processing apparatus 2 according to the present embodiment can be appropriately changed within a range where diagnosis of the cutting blade 70 is possible. For example, instead of providing the monitoring unit 94 (detection unit 98) on the blade cover 82 of the processing unit 42 (see FIGS. 2(A) and 2(B)), the detection unit may be attached to a component other than the processing unit 42.

[0123] For example, a detection unit including a light projecting unit and a light receiving unit may be installed on the X-axis movement table 10 or the chuck table 18 (see FIG. 1). In this case, the position of the detection unit in the X-axis direction can be controlled by the movement unit 6. Then, when diagnosing the cutting blade 70, the positional relationship between the cutting blade 70 and the detection unit is adjusted by operating the movement unit 6 and the movement unit 24. Thereby, the tip portion of the cutting blade 70 can be positioned between the light projecting unit and the light receiving unit.

[0124] In addition, the structure, method, etc. according to the above embodiment can be appropriately changed and implemented without departing from the scope of the object of the present invention.

Explanation of Reference Numerals

[0125] 11 Workpiece 11a Surface (upper surface) 11b Back surface (lower surface) 13 Frame 15 Film 2 Processing apparatus (cutting apparatus) 4 Base 6 Movement unit (movement mechanism) 8 X-axis guide rail 10 X-axis moving table 12 X-axis ball screw 14 X-axis pulse motor 16 Table base 18 Chuck table (holding table) 18a Holding surface 18b Clamp 20 Water case 22 Support structure 24 Moving unit (moving mechanism) 26 Y-axis guide rail 28 Y-axis moving plate 30 Y-axis ball screw 32 Y-axis pulse motor 34 Z-axis guide rail 36 Z-axis moving plate 38 Z-axis ball screw 40 Z-axis pulse motor 42 Processing unit (cutting unit) 44 Imaging unit 46 Display unit (display section, display device) 48 Notification unit (notification section, notification device) 50 Controller (control unit, control section, control device) 60 Housing 62 Spindle 64 Blade mount 64a Flange portion 64b Support shaft (boss portion) 66 Fixed nut 70 Cutting blade 70a Cutting edge (outer periphery) 72 Hub base 72a First surface (front surface) 72b Second surface (rear surface) 72c Through hole 72d Protrusion 74 Cutting edge 76a, 76b Chip 80 Support member 82 Blade cover 84 First connection portion 86 Nozzle (Cooler Nozzle) 88 Second Connection Part 90 Third Connection Part 92 Nozzle (Spray Nozzle) 94 Monitoring Unit 96 Frame 96a Accommodation Part 98 Detection Unit 100 Ball Screw 102 Pulse Motor 104 Detection Part 104a Base 104b Light Projection Part 104c Light Receiving Part 104d Blade Insertion Part 106 Light Source 108 Photoelectric Conversion Part 110 Processing Device 112 Chip Detection Part 114 Diagnosis Part 116 Notification Control Part 120 Memory Device 122 Threshold Memory Part 130 Peak 132 Peak 134 Peak 136 Peak 138 Peak 140 Peak 142 Peak 144 Peak

Claims

1. A method for diagnosing a cutting blade, which diagnoses the state of the cutting blade, comprising: a positioning step of positioning a tip region of the cutting blade between a light projecting unit that irradiates light and a light receiving unit that receives the light irradiated from the light projecting unit; a chipping calculation step of irradiating the light from the light projecting unit toward the light receiving unit after the positioning step, and calculating the size and number of chips present in part or all of the tip region of the cutting blade based on the amount of light received by the light receiving unit; a diagnosis step of diagnosing the state of the cutting blade based on the size and number of chips calculated in the chipping calculation step.

2. The method for diagnosing a cutting blade according to claim 1, wherein the size of the chip is the length or width of the chip.

3. In the chipping calculation step, the number of chips for each size of the chip is calculated, and in the diagnosis step, the state of the cutting blade is diagnosed by comparing the number of chips for each size of the chip with a reference value of the number of chips set for each size of the chip. The method for diagnosing a cutting blade according to claim 1 or 2.

4. A cutting method for cutting a workpiece, comprising: a holding step of holding the workpiece by a holding table; a cutting step of cutting the workpiece by causing the cutting blade to penetrate the workpiece by relatively moving the cutting blade and the holding table while rotating the cutting blade after the holding step; a positioning step of positioning a tip region of the cutting blade between a light projecting unit that irradiates light and a light receiving unit that receives the light irradiated from the light projecting unit; a chipping calculation step of irradiating the light from the light projecting unit toward the light receiving unit after the positioning step, and calculating the size and number of chips present in part or all of the tip region of the cutting blade based on the amount of light received by the light receiving unit; a diagnosis step of diagnosing the state of the cutting blade based on the size and number of chips calculated in the chipping calculation step.

5. The cutting method according to claim 4, wherein the size of the chip is the length or width of the chip.

6. In the chipping calculation step, the number of chips for each size of the chip is calculated, and in the diagnosis step, the state of the cutting blade is diagnosed by comparing the number of chips for each size of the chip with a reference value of the number of chips set for each size of the chip. The cutting method according to claim 4 or 5.

7. A processing apparatus for processing a workpiece, a spindle to which a cutting blade for cutting the workpiece is attached, a blade tip detection unit having a light projecting unit that irradiates light and a light receiving unit that receives the light irradiated from the light projecting unit, a processing device and a storage device, and a controller capable of controlling the operations of the cutting blade and the blade tip detection unit according to a program stored in the storage device, the controller, according to the program, a procedure for positioning a tip region of the cutting blade between the light projecting unit and the light receiving unit, a procedure for irradiating the light from the light projecting unit toward the light receiving unit and calculating the size and number of chips present in part or all of the tip region of the cutting blade based on the amount of light received by the light receiving unit, a procedure for diagnosing the state of the cutting blade based on the calculated size and number of the chips, a processing apparatus that executes the procedures.

8. The processing apparatus according to claim 7, wherein the size of the chip is the length or width of the chip.

9. The processing apparatus according to claim 7 or 8, wherein the controller calculates the number for each size of the chip and diagnoses the state of the cutting blade by comparing the number for each size of the chip with a reference value of the number of the chips set for each size of the chip.

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