Method of diagnosing cutting blade, method of cutting workpiece, and processing apparatus

Abstract

To provide a method of diagnosing a cutting blade capable of detecting clogging of the cutting blade.SOLUTION: A method of diagnosing a cutting blade for diagnosing a state of the cutting blade that cuts a workpiece includes a positioning step of positioning a distal end portion of the cutting blade between a light projecting section that radiates light and a light receiving section that receives the light radiated from the light projecting section; a shape identifying step of radiating the light from the light projecting section toward the light receiving section in a state in which the distal end portion of the cutting blade is positioned between the light projecting section and the light receiving section and identifying a shape of a portion or the whole of the distal end of the cutting blade based on an amount of light received by the light receiving section; and a diagnosis step of diagnosing whether or not clogging has occurred in the cutting blade based on the shape of the distal end of the cutting blade identified in the shape identifying step.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a method for diagnosing a cutting blade for diagnosing the state of a cutting blade that cuts a workpiece, and a method and a processing apparatus for cutting a workpiece with the cutting blade.

Background Art

[0002] By dividing a wafer on which a plurality of devices are formed into individual pieces, a plurality of device chips each including a device are manufactured. Further, 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), a package substrate is obtained. By dividing this package substrate into individual pieces, a plurality of package devices each including a plurality of packaged device chips are manufactured. Device chips and package devices are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] For dividing workpieces such as wafers and package substrates, a processing apparatus is used. For example, the processing apparatus includes a chuck table that holds a workpiece and a processing unit that performs cutting on the workpiece, and an annular cutting blade is mounted on the processing unit. By holding the workpiece with the chuck table and cutting into the workpiece while rotating the cutting blade, the workpiece is cut and divided (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The cutting blade used for cutting a workpiece is formed by fixing abrasive grains made of diamond or the like with a binder. Then, when the cutting blade is rotated at high speed and cut into the workpiece, the abrasive grains protruding from the binder collide with the workpiece, and thereby the workpiece is subjected to cutting.

[0006] However, when cutting a workpiece with a cutting blade, a phenomenon called "clogging" may occur in which the chips (processing chips) generated by the cutting process adhere to the abrasive grains of the cutting blade and the gaps between the abrasive grains. When clogging occurs, the abrasive grains are buried in the processing chips, preventing the appropriate protrusion of the abrasive grains, and the cutting ability of the cutting blade decreases. As a result, the force (processing load) acting between the workpiece and the cutting blade during cutting increases, and inconveniences such as poor processing and breakage of the cutting blade are likely to occur.

[0007] Therefore, when clogging occurs in the cutting blade, measures such as dressing in which the cutting blade is cut into a predetermined member (dressing board) to intentionally wear the tip of the cutting blade, or replacement of the cutting blade are taken. However, clogging of the cutting blade is difficult to detect compared to abnormalities such as chipping of the cutting blade and is often overlooked. As a result, cutting of the workpiece may continue with the cutting blade clogged, and there is a risk that poor processing and breakage of the cutting blade cannot be avoided.

[0008] The present invention has been made in view of such problems, and an object thereof is to provide a diagnostic method for a cutting blade capable of detecting clogging of the cutting blade, a method for cutting a workpiece, and a processing apparatus.

Means for Solving the Problems

[0009] 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 for cutting a workpiece, the method comprising: a positioning step of positioning a tip portion 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 shape specifying step of irradiating the light from the light projecting unit toward the light receiving unit with the tip portion of the cutting blade positioned between the light projecting unit and the light receiving unit, and specifying a shape of a part or the whole of the tip of the cutting blade based on the amount of light received by the light receiving unit; and a diagnosing step of diagnosing whether clogging has occurred in the cutting blade based on the shape of the tip of the cutting blade specified in the shape specifying step.

[0010] Preferably, in the diagnosing step, it is diagnosed whether clogging has occurred in the cutting blade based on the number of irregularities present at the tip portion of the cutting blade.

[0011] According to another aspect of the present invention, there is provided a method for cutting a workpiece with a cutting blade, the method comprising: a cutting step of cutting the workpiece by making a cut into the workpiece while rotating the cutting blade; a positioning step of positioning a tip portion 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 shape specifying step of irradiating the light from the light projecting unit toward the light receiving unit with the tip portion of the cutting blade positioned between the light projecting unit and the light receiving unit, and specifying a shape of a part or the whole of the tip of the cutting blade based on the amount of light received by the light receiving unit; and a diagnosing step of diagnosing whether clogging has occurred in the cutting blade based on the shape of the tip of the cutting blade specified in the shape specifying step.

[0012] Preferably, in the diagnosing step, it is diagnosed whether clogging has occurred in the cutting blade based on the number of irregularities present at the tip portion of the cutting blade.

[0013] Furthermore, according to another aspect of the present invention, there is provided a processing apparatus for cutting a workpiece with a cutting blade, the processing apparatus including a spindle to which the cutting blade is attached, a light projecting unit that irradiates light, and a light receiving unit that receives the light irradiated from the light projecting unit, a detection unit having the above components, and a controller. The controller identifies the shape of part or all of the tip of the cutting blade based on the amount of light received by the light receiving unit when the light is irradiated from the light projecting unit toward the light receiving unit with the tip of the cutting blade positioned between the light projecting unit and the light receiving unit, and diagnoses whether clogging has occurred in the cutting blade based on the shape of the tip of the cutting blade.

[0014] Preferably, the controller diagnoses whether clogging has occurred in the cutting blade based on the number of irregularities present at the tip of the cutting blade.

Advantages of the Invention

[0015] In the method for diagnosing a cutting blade, the method for cutting a workpiece, and the processing apparatus according to one aspect of the present invention, the shape of the tip of the cutting blade is identified by irradiating light, and it is diagnosed whether clogging has occurred in the cutting blade based on the shape of the tip of the cutting blade. Thereby, it becomes possible to timely confirm the presence or absence of clogging in the cutting blade, and it is possible to prevent inconveniences such as defective processing and breakage of the cutting blade.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments 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 X-axis direction (processing feed direction, first horizontal direction, front-rear direction) and the Y-axis direction (index feed direction, second horizontal direction, left-right direction) are perpendicular to each other. Also, the Z-axis direction (vertical direction, height direction, vertical direction) is perpendicular to the X-axis direction and the Y-axis direction.

[0018] The workpiece 11 is a member to be cut 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) and back surfaces (lower surface) that are generally parallel to each other.

[0019] The workpiece 11 is divided into a plurality of rectangular regions by streets (lines to be divided) arranged in a grid pattern so as to intersect each other. Further, 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 including a device are manufactured.

[0020] 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 (such as GaAs, InP, GaN, SiC), glass, ceramics, resin, metal, etc. Further, 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.

[0021] 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, a package substrate is formed by mounting a plurality of device chips on a predetermined substrate and covering 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.

[0022] When machining the workpiece 11 with the machining apparatus 2, the workpiece 11 is supported by the frame 13 for the convenience of handling (transporting, holding, etc.) the workpiece 11. 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.

[0023] A circular sheet 15 is fixed to the workpiece 11 and the frame 13. For example, as the sheet 15, a tape including a film-shaped base material formed in a circular shape and an adhesive layer (paste layer) provided on the base material is used. However, the sheet 15 may be a thermocompression bonding sheet that does not have an adhesive layer and can be thermocompression bonded to the workpiece 11 and the frame 13.

[0024] With the workpiece 11 disposed inside the opening of the frame 13, the central portion of the sheet 15 is attached to the back surface side of the workpiece 11, and the outer peripheral portion of the sheet 15 is attached to the frame 13. Thereby, the workpiece 11 is supported by the frame 13 via the sheet 15.

[0025] The machining apparatus 2 includes a base 4 that supports or houses each component constituting the machining apparatus 2. A moving unit (moving mechanism) 6 is installed on the upper surface of the base 4. 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.

[0026] A nut portion (not shown) is provided on the lower surface (back surface) side of the X-axis moving table 10. An X-axis ball screw 12 arranged along the X-axis direction is screwed into the nut portion between the pair of X-axis guide rails 8. 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.

[0027] On the upper surface (front surface) of the X-axis moving table 10, a cylindrical 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.

[0028] The upper surface of the chuck table 18 is a flat surface generally 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 the 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.

[0029] 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 generally parallel to the Z-axis direction is connected to the chuck table 18.

[0030] Around the moving unit 6, a water case 20 for temporarily storing the waste liquid generated during the operation of the processing apparatus 2 is provided. 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 apparatus 2 via a drain (not shown) etc. at a predetermined timing.

[0031] Further, on the upper surface side of the base 4, a portal-shaped support structure 22 is installed so as to straddle the moving unit 6. At both ends on the front surface (front side) of the support structure 22, a pair of moving units (moving mechanisms) 24 are installed.

[0032] Specifically, on the front side of the support structure 22, a pair of Y-axis guide rails 26 are fixed along the Y-axis direction. On the pair of Y-axis guide rails 26, flat Y-axis movement plates 28 provided on a pair of moving units 24 are slidably mounted along the Y-axis guide rails 26. Further, between the pair of Y-axis guide rails 26, a pair of Y-axis ball screws 30 are provided along the Y-axis direction.

[0033] On the rear surface side of the Y-axis movement plate 28, a nut portion (not shown) is provided, 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 movement plate 28 moves in the Y-axis direction along the Y-axis guide rails 26.

[0034] On the front surface side of the Y-axis movement plate 28, a pair of Z-axis guide rails 34 are fixed along the Z-axis. On the pair of Z-axis guide rails 34, a flat Z-axis movement plate 36 is slidably mounted along the Z-axis guide rails 34. Further, between the pair of Z-axis guide rails 34, a Z-axis ball screw 38 is provided along the Z-axis direction.

[0035] On the rear surface side of the Z-axis movement plate 36, a nut portion (not shown) is provided, and the Z-axis ball screw 38 is screwed into this nut portion. Further, 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 movement plate 36 moves in the Z-axis direction along the Z-axis guide rails 34.

[0036] 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).

[0037] 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 imaged image of the workpiece 11 is acquired. The imaged image is used for alignment between the workpiece 11 and the cutting blade 70 and evaluation of the workpiece 11.

[0038] When the moving unit 6 is operated to move the X-axis moving table 10 along the X-axis direction, the chuck table 18, the processing unit 42 and the imaging unit 44 move relatively along the X-axis direction. Also, when the moving unit 24 is operated to move the Y-axis moving plate 28 along the Y-axis direction, the chuck table 18, the processing unit 42 and the imaging unit 44 move relatively along the Y-axis direction. Further, when the moving unit 24 is operated to move the Z-axis moving plate 36 along the Z-axis direction, the chuck table 18, the processing unit 42 and the imaging unit 44 move relatively (ascend and descend) along the Z-axis direction.

[0039] When cutting blades 70 are respectively attached to a pair of processing units 42, the pair of cutting blades 70 are arranged to face each other. That is, the processing device 2 is a so-called facing dual spindle type cutting device. However, the number of processing units provided in the processing device 2 may be one set.

[0040] On the front side of the processing device 2, a display unit (display section, display device) 46 is provided. The display unit 46 is composed of various displays and displays information (processing conditions, processing status, etc.) regarding the processing device 2 or the workpiece 11, an operation screen, etc. 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 section, input device) for inputting information to the processing device 2, and the operator can input information to the processing device 2 by a touch operation on the display unit 46. However, the input unit may be an electronic device (mouse, keyboard, transceiver, etc.) provided independently of the display unit 46.

[0041] On the upper part of the processing device 2, a notification unit (notification section, notification device) 48 for notifying the operator of information is provided. For example, a display 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 display 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.

[0042] 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.

[0043] The controller 50 controls the operations of the respective components of the processing apparatus 2 by outputting control signals to the respective components, and operates the processing apparatus 2. For example, the controller 50 is configured by a computer, and includes a processing unit that executes processes such as calculations necessary for the operation of the processing apparatus 2, and a storage unit that stores various types of information (data, programs, etc.) used for the operation of the processing apparatus 2. The processing unit is configured by a processor such as a CPU (Central Processing Unit), and the storage unit is configured by a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory). Note that the specific functions of the controller 50 will be described later (see FIG. 4).

[0044] 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.

[0045] The processing unit 42 includes a cylindrical housing 60. The housing 60 houses a columnar spindle 62 (see FIG. 2(B)) arranged along the Y-axis direction. The tip end portion (one end side) of the spindle 62 is exposed from the housing 60. Further, a rotation 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.

[0046] A blade mount 64 (see FIG. 2(B)) is fixed to the tip end portion of the spindle 62. The blade mount 64 is made of a metal such as an aluminum alloy, and includes a disk-shaped flange portion 64a and a columnar 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.

[0047] 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.

[0048] 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. Further, 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 a portion that is gripped when the cutting blade 70 is attached and detached.

[0049] On the second surface 72b side of the hub base 72, an annular cutting edge 74 is formed annularly along the outer peripheral edge of the hub base 72. The cutting edge 74 corresponds to a machining portion that contacts the workpiece 11 and cuts the workpiece 11. Note that the outer diameter of the cutting edge 74 is larger than the outer diameter of the hub base 72. Therefore, the cutting edge 74 is arranged so as to protrude radially outward from the outer peripheral edge of the hub base 72.

[0050] As shown in FIG. 2(B), the cutting blade 70 is attached to the processing 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 to the support shaft 64b with the cutting blade 70 attached to the blade mount 64, the cutting blade 70 is sandwiched between the flange portion 64a and the fixing nut 66.

[0051] In this way, the cutting blade 70 is attached to the tip of the spindle 62 via the blade mount 64. Then, when a rotational drive source (not shown) connected to the spindle 62 is actuated, the cutting blade 70 rotates around a rotation axis generally parallel to the Y-axis direction by the power transmitted from the rotational drive source via the spindle 62 and the blade mount 64.

[0052] Note that the cutting blade 70 may be a washer-type cutting blade (washer blade). In this case, the cutting blade 70 is composed of only an annular cutting edge having abrasive grains and a binder for fixing the abrasive grains made of metal, ceramics, resin, or the like.

[0053] A plate-shaped support member 80 is fixed to the tip of the housing 60. Also, 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 portions 84 are provided at one end of the blade cover 82, and a second connection portion 88 and a third connection portion 90 are provided at the other end of the blade cover 82. Pipes (not shown), such as pipes for supplying a liquid (processing fluid) such as pure water, are connected to the first connection portion 84, the second connection portion 88, and the third connection portion 90, respectively.

[0054] A pair of nozzles (cooler nozzles) 86 arranged to sandwich the lower end portion of the cutting blade 70 are connected to the pair of first connection portions 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 fluid is supplied to the first connection portion 84, the processing fluid 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.

[0055] The second connection portion 88 is connected to a nozzle (shower nozzle, not shown) provided inside the blade cover 82. The tip of the shower nozzle opens toward the outer peripheral edge of the cutting blade 70. When machining fluid is supplied to the second connection portion 88, the machining fluid flows into the shower nozzle, and the machining fluid is supplied from the tip of the shower nozzle to the outer peripheral edge of the cutting blade 70.

[0056] The third connection portion 90 is connected to a pair of nozzles (spray nozzles) 92 that open downward. When machining fluid is supplied to the third connection portion 90, the machining fluid flows into the nozzles 92, and the machining fluid is supplied from the tips of the nozzles 92 toward the holding surface 18a (see FIG. 1) of the chuck table 18.

[0057] When machining the workpiece 11, the workpiece 11 (see FIG. 1) is held by the chuck table 18, and the cutting blade 70 is rotated while cutting 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 nozzles 86, the shower nozzle (not shown), and the nozzles 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.

[0058] 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 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.

[0059] 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 body 96, and a pulse motor 102 is connected to an end of the ball screw 100. The detection unit 98 includes a nut portion (not shown), and the ball screw 100 is screwed into the 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. Thereby, the height position (position in the Z-axis direction) of the detection unit 98 is adjusted.

[0060] 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.

[0061] 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 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 of the cutting blade 70 (cutting edge 74) is inserted.

[0062] 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 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.

[0063] A photoelectric conversion unit 108 that generates a signal (received light amount signal) corresponding to the amount of light received by the light receiving unit 104c (received light amount) 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 received light amount signal corresponding to the received light amount of the light receiving unit 104c is generated. The received light amount signal generated by the photoelectric conversion unit 108 is output to the controller 50.

[0064] 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 while rotating the cutting blade 70 mounted on the machining unit 42, the workpiece 11 is cut into. Thereby, a predetermined cutting process is performed on the workpiece 11.

[0065] When cutting the workpiece 11 with the cutting blade 70, chips (machining chips) are generated. Although these machining chips are washed away by the machining fluid supplied during cutting, a part of them may adhere to the cutting blade 70 without being removed. Thereby, a phenomenon called "clogging" occurs in which the machining chips adhere to the abrasive grains of the cutting blade 70 and the gaps between the abrasive grains. When clogging occurs, the abrasive grains are buried in the machining chips and the appropriate protrusion of the abrasive grains is hindered, and the cutting ability of the cutting blade 70 decreases. As a result, the force (machining load) acting between the workpiece 11 and the cutting blade 70 during cutting increases.

[0066] FIG. 5(A) is a cross-sectional view showing the tip of the cutting blade 70 where clogging has not occurred. The tip (outer peripheral part) of the cutting blade 70 is constituted by a cutting edge 74. For example, the cutting edge 74 is constituted by an electroformed grindstone including abrasive grains 76 made of diamond, cubic boron nitride (cBN), or the like, and a bonding material (bonding material) 78 such as a nickel plating layer that fixes the abrasive grains 76. However, there is no limitation on the materials of the abrasive grains 76 and the bonding material 78.

[0067] In the cutting blade 70 without clogging, the abrasive grains 76 protrude moderately from the binder 78. Due to the protrusion of the abrasive grains 76, irregularities are formed at the tip of the cutting blade 70. Then, the surface of the binder 78 and the abrasive grains 76 protruding from the surface of the binder 78 constitute the tip (outer peripheral edge) 70a of the cutting blade 70. When the cutting blade 70 is rotated and cut into the workpiece 11, the abrasive grains 76 protruding at the tip 70a of the cutting blade 70 collide with the workpiece 11, and the workpiece 11 is cut.

[0068] FIG. 5(B) is a cross-sectional view showing the tip of the cutting blade 70 with clogging. When the machining chips 17 generated by cutting the workpiece 11 adhere and accumulate between the abrasive grains 76 or between the abrasive grains 76, clogging occurs and the abrasive grains 76 are buried in the machining chips 17. As a result, the abrasive grains 76 do not protrude or the protrusion of the abrasive grains 76 is insufficient, and part or all of the tip 70a of the cutting blade 70 is constituted by the machining chips 17. When the workpiece 11 is cut with the cutting blade 70 in such a state, the machining load increases, and inconveniences such as machining defects and breakage of the cutting blade 70 are likely to occur.

[0069] Therefore, in the present 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 specify the shape of the tip 70a of the cutting blade 70, and diagnoses whether clogging has occurred in the cutting blade 70 based on the shape of the tip 70a of the cutting blade 70. Thereby, it is possible to avoid continuing the cutting of the workpiece 11 in a state where the cutting blade 70 is clogged, and it is possible to avoid machining defects and breakage of the cutting blade 70.

[0070] Hereinafter, a specific example of the cutting method of the workpiece according to the present embodiment will be described. FIG. 6 is a flowchart showing the cutting method of the workpiece. In the present embodiment, after cutting the workpiece 11 with the cutting blade 70 in the cutting step S1, the positioning step S2, the shape identification step S3, and the diagnosis step S4 are sequentially executed to diagnose the state of the cutting blade 70. Note that the positioning step S2, the shape identification step S3, and the diagnosis step S4 correspond to the diagnosis method of the cutting blade according to the present embodiment.

[0071] In the cutting step S1, the workpiece 11 is cut by causing the cutting blade 70 to rotate and penetrate into the workpiece 11. A specific example of the cutting process in the cutting step S1 will be described with reference to FIG. 1.

[0072] When machining the workpiece 11 with the machining apparatus 2, the workpiece 11 is held by the chuck table 18. 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 sheet 15. Further, 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 sheet 15.

[0073] Next, 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. Further, 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) of the workpiece 11. Furthermore, 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.

[0074] 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 processing unit 42 move relative to each other along the X-axis direction. Consequently, 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, coolant is supplied to the workpiece 11 and the cutting blade 70 during the cutting of the workpiece 11.

[0075] Thereafter, by repeating the same procedure, the workpiece 11 is cut and divided along other streets. Then, when the workpiece 11 is cut along all the streets, the workpiece 11 is divided into a plurality of chips.

[0076] However, the content of the processing in the cutting step S1 is not limited to the above. For example, by cutting the workpiece 11 with the cutting blade 70, grooves with a depth less than the thickness of the workpiece 11 can also be formed on the surface (upper surface) 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) of the workpiece 11 and above the back surface (lower surface) of the workpiece 11. By cutting the cutting blade 70 into the workpiece 11 in this state, grooves are formed in the workpiece 11 along the streets.

[0077] 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 of the workpiece 11, the workpiece 11 is divided into a plurality of chips along the streets. In this way, the method of dividing the workpiece 11 by performing grinding after cutting is called the DBG (Dicing Before Grinding) process.

[0078] Next, the tip 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 S2). In the positioning step S2, with the cutting blade 70 attached to 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 (upper end) of the cutting blade 70 is inserted into the blade insertion portion 104d (see FIG. 4). Thereby, the tip of the cutting blade 70 is positioned between the light projecting unit 104b and the light receiving unit 104c.

[0079] However, there is no limitation on the timing for performing the positioning step S2. For example, after the cutting blade 70 is attached to the processing unit 42 (see FIGS. 2(A) and 2(B)), the positioning step S2 may be performed before the cutting of the workpiece 11 is started (before the execution of the cutting step S1).

[0080] Next, a part or the whole shape of the tip 70a of the cutting blade 70 is specified (shape specifying step S3), and it is diagnosed whether clogging has occurred in the cutting blade 70 based on the shape of the tip 70a of the cutting blade 70 (diagnosis step S4). The shape specifying step S3 and the diagnosis step S4 are performed by the controller 50 and the detection unit 98 (see FIG. 4).

[0081] As shown in FIG. 4, the controller 50 includes a processing unit 110 that executes various processes necessary for diagnosing the state of the cutting blade 70, and a storage unit 120 that stores information (data, programs, etc.) used for the processes by the processing unit 110 and information obtained by the processes by the processing unit 110. Further, the processing unit 110 includes a shape specifying unit 112 that specifies a part or the whole shape of the tip 70a 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 clogging has occurred in the cutting blade 70 based on the shape of the tip 70a of the cutting blade 70 specified by the shape specifying unit 112, and a notification control unit 116 that controls the notification of the diagnosis result by the diagnosis unit 114.

[0082] In the shape determination step S3, the cutting blade 70 is rotated at a predetermined speed with the tip (upper end) of the cutting blade 70 positioned between the light projecting unit 104b and the light receiving unit 104c. 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.

[0083] Part of the light irradiated from the light projecting 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.

[0084] For example, the photoelectric conversion unit 108 detects the light received by the light receiving unit 104c a plurality of times at a predetermined period (sampling period) during the rotation of the cutting blade 70, 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.

[0085] Here, the shape of the tip 70a of the cutting blade 70 is reflected in the light reception amount of the light receiving unit 104c. Therefore, whether or not clogging has occurred in the cutting blade 70 causes a change in the light reception amount of the light receiving unit 104c, and the presence or absence of clogging is also reflected in the light reception amount signal generated by the photoelectric conversion unit 108.

[0086] FIG. 7(A) is a graph showing the amount of light received by the light receiving unit 104c when detecting the cutting blade 70 without clogging. When there is no clogging in the cutting blade 70, unevenness is formed at the tip of the cutting blade 70 due to the abrasive grains 76 protruding from the bonding material 78 (see FIG. 5(A)). Then, the light traveling from the light projecting unit 104b to the light receiving unit 104c is blocked according to the unevenness at the tip of the cutting blade 70. Specifically, when a concave portion (a region where the abrasive grains 76 do not protrude) of the cutting blade 70 is positioned between the light projecting unit 104b and the light receiving unit 104c, the amount of light blocked decreases, and the amount of light received by the light receiving unit 104c increases. On the other hand, when a convex portion (a region where the abrasive grains 76 protrude) of the cutting blade 70 is positioned between the light projecting unit 104b and the light receiving unit 104c, the amount of light blocked increases, and the amount of light received by the light receiving unit 104c decreases. Thus, the unevenness at the tip of the cutting blade 70 is reflected in the amount of light received by the light receiving unit 104c, and the variation (increase or decrease) in the amount of light received becomes large.

[0087] FIG. 7(B) is a graph showing the amount of light received by the light receiving unit 104c when detecting the cutting blade 70 with clogging. When clogging occurs in the cutting blade 70, part or all of the abrasive grains 76 and the bonding material 78 are covered by the machining chips 17 (see FIG. 5(B)). As a result, the unevenness at the tip of the cutting blade 70 becomes smaller, and the tip 70a of the cutting blade 70 approaches a perfect circle. Consequently, it becomes difficult for unevenness to appear in the amount of light received by the light receiving unit 104c, and the variation (increase or decrease) in the amount of light received by the light receiving unit 104c becomes smaller compared to the case where there is no clogging.

[0088] Note that the cutting blade 70 is mounted so that its center coincides with the rotation axis of the spindle 62 (see FIG. 2(B)). However, due to mounting errors when mounting 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 be slightly displaced from the center of the spindle 62. In this case, the distance from the rotation center of the cutting blade 70 to the tip 70a of the cutting blade 70 is not constant, and the cutting blade 70 is in an eccentric state.

[0089] FIG. 8(A) is a graph showing the amount of light received by the light receiving portion 104c when detecting the eccentric cutting blade 70 without clogging. FIG. 8(B) is a graph showing the amount of light received by the light receiving portion 104c when detecting the eccentric cutting blade 70 with clogging. When the cutting blade 70 is eccentric, as the cutting blade 70 rotates, the upper end position of the cutting blade 70 fluctuates, 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) and 8(B), undulations occur in the change of the amount of light received. However, even when the cutting blade 70 is in an eccentric state, unevenness reflecting the shape of the tip 70a of the cutting blade 70 appears in the change of the amount of light received.

[0090] As described above, the shape of the tip 70a of the cutting blade 70 changes depending on the presence or absence of clogging, and the shape of the tip 70a of the cutting blade 70 is reflected in the change of the amount of light received by the light receiving portion 104c. Then, by detecting the amount of light received by the light receiving portion 104c a plurality of times at a predetermined sampling period while the cutting blade 70 makes one rotation, a light reception amount signal corresponding to the shape of the entire (entire circumference) tip 70a of the cutting blade 70 is obtained. The light reception amount signal thus obtained is input from the photoelectric conversion unit 108 to the shape specifying unit 112 of the processing unit 110 (see FIG. 4).

[0091] The shape specifying unit 112 specifies the shape of the tip 70a of the cutting blade 70 based on the light reception amount signal. For example, the shape specifying unit 112 may set the change in the amount of light received (see FIGS. 7(A) to 8(B)) as the shape of the tip 70a of the cutting blade 70 as it is, or may set a curve approximating the change in the amount of light received as the shape of the tip 70a of the cutting blade 70. Then, the information (shape information) indicating the shape of the tip 70a of the cutting blade 70 specified by the shape specifying unit 112 is stored in the shape information storage unit 122 included in the storage unit 120.

[0092] In this way, the shape of the tip 70a of the cutting blade 70 is specified in the shape specifying step S3. In the above description, the case where the shape of the entire circumference of the tip 70a of the cutting blade 70 is specified has been described. However, in the shape specifying step S3, a part of the shape of the tip 70a of the cutting blade 70 may be specified. In this case, the detection of the amount of light received by the light receiving portion 104c is stopped before the cutting blade 70 makes one rotation, and the shape information reflecting a part of the shape of the tip 70a of the cutting blade 70 is stored in the shape information storage portion 122.

[0093] Also, in the above description, an example in which the amount of light received by the light receiving portion 104c is detected a plurality of times while rotating the cutting blade 70 has been described. However, the detection procedure of the amount of light received is not limited to this. For example, a process of rotating the cutting blade 70 by a predetermined angle and then stopping it, and a process of detecting the amount of light received by the light receiving portion 104c while the cutting blade 70 is in a stopped state (non-rotating state) may be alternately repeated a plurality of times to acquire a light reception amount signal.

[0094] Next, the controller 50 diagnoses whether or not clogging has occurred in the cutting blade 70 based on the shape of the tip 70a of the cutting blade 70 specified in the shape specifying step S3 (diagnosis step S4). In the diagnosis step S4, the diagnosis unit 114 determines the presence or absence of clogging based on the shape information.

[0095] For example, the diagnosis unit 114 diagnoses whether or not clogging has occurred in the cutting blade 70 based on the number of irregularities present at the tip of the cutting blade 70. In this case, the diagnosis unit 114 includes a counting unit 114a that counts the number of irregularities present at the tip of the cutting blade 70, and a determination unit 114b that determines the presence or absence of clogging based on the number of irregularities counted by the counting unit 114a.

[0096] When abrasive grains 76 protrude at the tip of the cutting blade 70 (see Fig. 5(A)), as shown in Fig. 7(A), a plurality of convex portions 130 corresponding to the protruding abrasive grains 76 appear in the transition of the light reception amount of the light reception portion 104c. Therefore, the counting unit 114a extracts the convex portions 130 from the shape information (transition of the light reception amount) stored in the shape information storage unit 122 and counts the number of the convex portions 130.

[0097] For example, the counting unit 114a calculates the difference between the light reception amount and the maximum value A of the light reception amount for each rotation angle. max Then, the counting unit 114a recognizes a region where the difference between the light reception amount and the maximum value A is equal to or greater than a predetermined threshold value as the convex portion 130 and counts the number of the convex portions 130. In this case, convex portions having a predetermined size or more among the convex portions existing at the tip of the cutting blade 70 are the objects to be counted by the counting unit 114a. max However, there is no limitation on the method of counting the convex portions 130. For example, the counting unit 114a may calculate the inclination (gradient) of the light reception amount and count a region where the magnitude of the inclination of the light reception amount is equal to or greater than a predetermined threshold value as the convex portion 130. In this case, even when the cutting blade 70 is eccentric and undulations occur in the transition of the light reception amount (see Figs. 8(A) and 8(B)), the number of the convex portions 130 can be counted. Further, the counting unit 114a may count the number of concave portions included in the transition of the light reception amount.

[0098] The number of unevenness counted by the counting unit 114a is output to the determination unit 114b. Further, the storage unit 120 includes a threshold value storage unit 124 in which a threshold value (reference value) of the number of unevenness is stored. The threshold value of the number of unevenness is preset before the execution of the diagnosis step S4 and stored in the threshold value storage unit 124. Then, the determination unit 114b determines whether clogging has occurred at the tip of the cutting blade 70 by comparing the number of unevenness counted by the counting unit 114a with the threshold value stored in the threshold value storage unit 124.

[0099]

[0100] ​Specifically, when there is no clogging in the cutting blade 70, there are many irregularities of a predetermined size or more due to the protrusion of the abrasive grains 76 at the tip of the cutting blade 70 (see Fig. 5(A)), and many irregularities of a predetermined size or more also appear in the transition of the received light amount. Therefore, when the number of irregularities counted by the counting unit 114a is equal to or greater than the threshold value (or exceeds the threshold value), the determination unit 114b determines that there is no clogging in the cutting blade 70.

[0101] On the other hand, when the cutting blade 70 is clogged, the abrasive grains protruding from the binder 78 are covered by the machining chips 17, and there are no irregularities of a predetermined size or more at the tip of the cutting blade 70, or the number thereof is small (see Fig. 5(B)). Therefore, it is difficult for irregularities of a predetermined size or more to appear in the transition of the received light amount. Therefore, when the number of irregularities is less than the threshold value (or less than or equal to the threshold value), the determination unit 114b determines that the cutting blade 70 is clogged.

[0102] The threshold value of the number of irregularities is appropriately set according to the size of the abrasive grains 76 contained in the cutting blade 70 and the like. For example, before machining the workpiece 11 with the cutting blade 70 (before the implementation of the cutting step S1), the counting unit 114a counts the number of irregularities (initial irregularity number) at the tip of the cutting blade 70 in a non-clogged state (preliminary measurement step), and the threshold value may be set based on the number of irregularities. In this case, a predetermined value smaller than the initial irregularity number is set as the threshold value of the number of irregularities.

[0103] In addition, the threshold value of the number of irregularities is set according to the range of the cutting blade 70 detected by the detection unit 98. For example, when the received light amount of the light receiving unit 104c is detected for the entire tip (entire circumference) of the cutting blade 70, the reference value of the number of irregularities in the entire tip of the cutting blade 70 is set as the threshold value. On the other hand, when the received light amount of the light receiving unit 104c is detected for a part of the tip of the cutting blade 70, the reference value of the number of irregularities in a part of the tip of the cutting blade 70 is set as the threshold value.

[0104] The result of the determination by the determination unit 114b is output to the notification control unit 116. When it is determined by the determination unit 114b that clogging has occurred, 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 to cause the display unit 46 to display information (such as a message) notifying the occurrence of clogging. Further, the notification control unit 116 outputs a control signal to the notification unit 48 to turn on or blink the notification unit 48. Thereby, the operator is notified of the occurrence of clogging.

[0105] In the above description, the case where the diagnosis unit 114 diagnoses the presence or absence of clogging based on the number of irregularities existing at the tip of the cutting blade 70 has been described. However, the diagnosis method by the diagnosis unit 114 is not limited. For example, when the cutting blade 70 is not eccentric (see FIGS. 7(A) and 7(B)), the diagnosis unit 114 may diagnose the presence or absence of clogging based on the amount of variation in the light reception amount (the difference between the minimum value and the maximum value).

[0106] Specifically, a threshold value of the amount of variation in the light reception amount is set in advance and stored in the storage unit 120. Then, the diagnosis unit 114 calculates the amount of variation in the light reception amount based on the shape information (transition of the light reception amount) stored in the shape information storage unit 122, and compares the amount of variation in the light reception amount with the threshold value.

[0107] When the amount of variation in the light reception amount is equal to or greater than the threshold value (or greater than the threshold value), the diagnosis unit 114 determines that there are rough irregularities at the tip of the cutting blade 70 and diagnoses that no clogging has occurred. On the other hand, when the amount of variation in the light reception amount is less than (or equal to) the threshold value, the diagnosis unit 114 determines that the tip of the cutting blade 70 has been smoothed by the adhesion of the machining chips 17 and determines that clogging has occurred. Then, the result of the diagnosis by the diagnosis unit 114 is output to the notification control unit 116.

[0108] As described above, by sequentially performing the positioning step S2, the shape identification step S3, and the diagnosis step S4, the method for diagnosing a cutting blade according to the present embodiment is realized. Then, by performing the positioning step S2 to the diagnosis step S4 after the cutting step S1, 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.

[0109] However, the positioning step S2 to the diagnosis step S4 may be performed before the cutting step S1. For example, after the cutting blade 70 is mounted on the processing unit 42 (see FIGS. 2(A) and 2(B)), the detection unit 98 is raised and lowered to perform the positioning step S2. Then, before the cutting of the workpiece 11 by the cutting blade 70 is started, the shape identification step S3 and the diagnosis step S4 are performed. Thereby, the state of the cutting blade 70 can be finally confirmed immediately before the cutting of the workpiece 11.

[0110] Furthermore, the positioning step S2 to the diagnosis step S4 can also be performed during the cutting step S1. 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 S2). 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 the shape of the tip 70a of the cutting blade 70 is identified by the shape identification unit 112 (shape identification step S3). Further, during the cutting of the workpiece 11, the presence or absence of clogging is diagnosed by the diagnosis unit 114 (diagnosis step S4). Thus, by performing the positioning step S2 to the diagnosis step S4 during the cutting of the workpiece 11, it is not necessary to separately secure time for diagnosing the cutting blade 70, and the processing efficiency is improved.

[0111] As described above, it is diagnosed whether clogging has occurred in the cutting blade 70 by the method for diagnosing a cutting blade according to the present embodiment. When it is diagnosed in the diagnosis step S4 that clogging has occurred in the cutting blade 70, measures are taken as necessary to avoid cutting the workpiece 11 with the cutting blade 70 in the clogged state.

[0112] For example, dressing is performed by causing the cutting blade 70 to cut into a predetermined member (dressing board) to intentionally wear the tip of the cutting blade 70, thereby eliminating clogging of the cutting blade 70 (clogging elimination 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.

[0113] By dressing the cutting blade 70, the tip of the cutting blade 70 wears, and the machining chips 17 attached to the tip of the cutting blade 70 are removed. As a result, the cutting blade 70 returns to a state in which the abrasive grains 76 protrude appropriately, and the cutting ability of the cutting blade 70 is restored.

[0114] Also, when it is difficult to eliminate clogging, 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 the clogged state is removed from the machining unit 42 (see FIGS. 2(A) and 2(B)). Thereafter, a new cutting blade 70 without clogging is attached to the machining unit 42, and the cutting of the workpiece 11 is resumed.

[0115] The cutting method of the workpiece according to this embodiment is realized by controlling the operations of the components of the processing apparatus 2 with a controller 50 (see FIGS. 1 and 4). Specifically, in a storage unit 120 (memory) of the controller 50, a program for causing the processing apparatus 2 to execute a cutting step S1, a positioning step S2, a shape identification step S3, a diagnosis step S4, a clogging elimination step, or a 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 the above-described steps.

[0116] 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 unit 120. As a result, a series of processes corresponding to 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 cutting method of the workpiece according to this embodiment is automatically performed.

[0117] As described above, in the processing apparatus 2 and the cutting method (diagnosis method of the cutting blade) of the workpiece according to this embodiment, the shape of the tip 70a of the cutting blade 70 is identified by irradiation with light, and it is diagnosed whether or not clogging has occurred in the cutting blade 70 based on the shape of the tip 70a of the cutting blade 70. Thereby, it becomes possible to timely confirm the presence or absence of clogging in the cutting blade 70, and it is possible to prevent inconveniences such as processing defects and breakage of the cutting blade 70 in advance.

[0118] Note that the configuration of the processing apparatus 2 according to this embodiment can be appropriately changed within a range in which diagnosis of the cutting blade 70 is possible. For example, instead of providing a 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.

[0119] For example, a detection unit including a light projecting unit and a light receiving unit may be installed on the X-axis moving 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 moving unit 6. When diagnosing the cutting blade 70, the positional relationship between the cutting blade 70 and the detection unit is adjusted by operating the moving unit 6 and the moving unit 24. Thereby, the tip of the cutting blade 70 can be positioned between the light projecting unit and the light receiving unit.

[0120] In addition, in this embodiment, the case where the cutting blade 70 includes abrasive grains and a binder has been described, but the type of the cutting blade 70 is not limited either. For example, the cutting blade 70 may be a metal saw (cemented carbide cutter). A metal saw is an annular machining tool made of a metal such as cemented carbide or stainless steel and does not contain abrasive grains. Further, a plurality of saw blades are provided at substantially equal intervals along the tip (outer peripheral edge) of the metal saw at the tip portion (outer peripheral portion) of the metal saw.

[0121] Unevenness is formed at the tip of the metal saw by a plurality of saw blades. When the workpiece 11 is cut with the metal saw, machining chips may enter and adhere between the saw blades, resulting in insufficient protrusion of the saw blades (clogging). Therefore, even when a metal saw is used as the cutting blade 70, it is preferable to perform the diagnosis method of the cutting blade according to this embodiment at a predetermined timing to diagnose whether clogging has occurred in the metal saw.

[0122] In addition, the structures, methods, etc. according to the above embodiments can be appropriately modified and implemented without departing from the scope of the object of the present invention.

Explanation of Reference Numerals

[0123] 11 Workpiece 13 Frame 15 Sheet 17 Machining chips 2 Machining apparatus (cutting apparatus) 4 Base 6 Moving unit (moving 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 Machining 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 Tip (outer peripheral edge) 72 Hub base 72a First surface (surface) 72b Second surface (back surface) 72c Through hole 72d Protrusion 74 Cutting edge 76 Abrasive grains 78 Binder (bonding material) 80 Support member 82 Blade cover 84 First connection part 86 Nozzle (cooler nozzle) 88 Second connection part 90 Third connection part 92 Nozzle (spray nozzle) 94 Monitoring unit 96 Frame body 96a Accommodation part 98 Detection unit 100 Ball screw 102 Pulse motor 104 Detection part 104a Base part 104b Light projecting part 104c Light receiving part 104d Blade insertion part 106 Light source 108 Photoelectric conversion part 110 Processing part 112 Shape specifying part 114 Diagnosis part 114a Counting part 114b Judgment part 116 Notification control part 120 Memory part 122 Shape information memory part 124 Threshold value memory part 130 Convex part

Claims

1. A method for diagnosing a cutting blade that diagnoses the state of a cutting blade for cutting a workpiece, comprising: a positioning step of positioning the tip 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 shape specifying step of irradiating the light from the light projecting unit toward the light receiving unit with the tip of the cutting blade positioned between the light projecting unit and the light receiving unit, and specifying a part or all of the shape of the tip of the cutting blade based on the amount of light received by the light receiving unit; a diagnosing step of diagnosing whether clogging has occurred in the cutting blade based on the shape of the tip of the cutting blade specified in the shape specifying step. The method for diagnosing a cutting blade is characterized by comprising the above steps.

2. The method for diagnosing a cutting blade according to claim 1, wherein in the diagnosing step, it is diagnosed whether clogging has occurred in the cutting blade based on the number of irregularities present at the tip of the cutting blade.

3. A method for cutting a workpiece with a cutting blade, comprising: a cutting step of cutting the workpiece by making a cut into the workpiece while rotating the cutting blade; a positioning step of positioning the tip 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 shape specifying step of irradiating the light from the light projecting unit toward the light receiving unit with the tip of the cutting blade positioned between the light projecting unit and the light receiving unit, and specifying a part or all of the shape of the tip of the cutting blade based on the amount of light received by the light receiving unit; a diagnosing step of diagnosing whether clogging has occurred in the cutting blade based on the shape of the tip of the cutting blade specified in the shape specifying step. The method for cutting a workpiece is characterized by comprising the above steps.

4. The method for cutting a workpiece according to claim 3, wherein in the diagnosing step, it is diagnosed whether clogging has occurred in the cutting blade based on the number of irregularities present at the tip of the cutting blade.

5. A processing apparatus for cutting a workpiece with a cutting blade, comprising: a spindle to which the cutting blade is attached; a 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 controller. The processing device is characterized in that the controller specifies the shape of part or all of the tip of the cutting blade based on the amount of light received by the light receiving part when the light is irradiated from the light projecting part toward the light receiving part with the tip of the cutting blade positioned between the light projecting part and the light receiving part, and diagnoses whether clogging has occurred in the cutting blade based on the shape of the tip of the cutting blade.

6. The processing device according to claim 5, wherein the controller diagnoses whether clogging has occurred in the cutting blade based on the number of irregularities present at the tip of the cutting blade.

Images