JP6846214B2 - Cutting equipment - Google Patents

Description

The present invention relates to a cutting device for cutting a plate-like object such as a semiconductor wafer with a cutting blade.

A plate-shaped workpiece represented by a semiconductor wafer is cut by, for example, a cutting device provided with an annular cutting blade and divided into a plurality of chips. If an abnormality such as chipping of the cutting blade, deterioration of cutting performance, contact with foreign matter, or change in machining load occurs during cutting of the workpiece, the cutting blade vibrates differently from the normal state. As a cutting device that detects vibration of such a cutting blade at the time of abnormality, the one disclosed in Patent Document 1 is known.

JP-A-2015-170743

When cutting as described above, cutting water is injected from a nozzle onto a cutting blade that rotates at high speed during cutting to cool the processing heat and wash away cutting debris generated by cutting from the workpiece. .. However, in the vibration detection of the cutting blade, there is a problem that the injection of the cutting water becomes noise and causes disturbance, and the vibration of the cutting blade cannot be properly collected.

The present invention has been made in view of this point, and one of the objects of the present invention is to provide a cutting apparatus capable of appropriately collecting elastic waves generated when cutting with a cutting means.

The cutting device of the present invention is a cutting device including at least a holding means for holding a work piece and a cutting means having a cutting blade for cutting the work piece held by the holding means, on a chuck table of the holding means. A water storage tank that stores the held work piece in a submerged state, a cutting water supply means that supplies cutting water to the water storage tank, and a cutting water supply means that are arranged in the cutting means and are generated when the work piece is cut by the cutting means. Equipped with an elastic wave detection sensor that detects the elastic wave to be cut, the workpiece held on the holding means is in a submerged state where the cutting water is stored in the water storage tank, and a part including the cutting part is cut in the water storage tank. It is characterized in that the part is cut by a cutting blade having a region exposed from the cutting water of the water storage tank while being immersed in water.

According to this configuration, the work piece is cut with the cutting blade in a submerged state, so that the cutting heat can be cooled and the cutting chips can be cleaned without injecting cutting water from the nozzle to the cutting location. You will be able to do it. Therefore, the injection of cutting water is no longer necessary, and when the elastic wave detection sensor detects the elastic wave generated during cutting, the disturbance noise caused by the injection of cutting water can be eliminated and the elastic wave can be appropriately collected. As a result, when an abnormality accompanied by vibration of the cutting blade occurs, such an abnormality can be accurately grasped.

In the cutting apparatus of the present invention, the cutting means includes a cutting blade, a rotary spindle that rotates with the cutting blade attached to the tip, and a housing that rotatably supports the rotary spindle, and the elastic wave detection sensor is attached to the cutting blade. It is preferable that the housing is positioned close to non-contact and submerged during cutting.

According to the present invention, since the workpiece is cut in a submerged state, elastic waves generated during cutting can be appropriately collected.

It is a perspective view of the cutting apparatus of this embodiment. It is sectional drawing around the chuck table of this embodiment. It is a figure which shows typically the cross section of the cutting means of this embodiment. It is an exploded perspective view of the cutting means of this embodiment. FIG. 5A is a graph showing an example of an output waveform from an elastic wave detection sensor, FIG. 5B is a graph showing an example of a waveform after Fourier transform, and FIG. 5C is an example of a waveform before and after the occurrence of an abnormality. It is a graph which shows. It is a cross-sectional schematic diagram around a cutting means and a chuck table of a modification.

Hereinafter, the cutting apparatus of the present embodiment will be described with reference to the attached drawings. FIG. 1 is a perspective view of the cutting device of the present embodiment. The cutting apparatus may be configured as long as it has a structure for detecting elastic waves during cutting as in the present embodiment, and is not limited to the configuration shown in FIG. 1. In FIG. 1, for convenience of explanation, some members are omitted, but the configuration normally provided by the cutting apparatus is assumed to be provided.

As shown in FIG. 1, the cutting apparatus 1 of the present embodiment cuts the workpiece W by relatively moving the cutting means 40 having the cutting blade 42 and the chuck table 3 holding the workpiece W. It is configured in. The workpiece W is carried into the cutting device 1 in a state of being supported by the ring frame F via the dicing tape T. The workpiece W may be a semiconductor wafer in which a semiconductor device is formed on a semiconductor substrate such as silicon or gallium arsenide, or an optical device wafer in which an optical device is formed on a ceramic, glass, or sapphire-based inorganic material substrate. Good.

The cutting device 1 includes a chuck table 3 provided on the base 2 and forming a holding means, and a cutting mechanism 4 for cutting a workpiece W held by the chuck table 3. A spinner cleaning mechanism 6 is provided on the base 2 at a position adjacent to the chuck table 3. In the spinner cleaning mechanism 6, after the cleaning water is sprayed toward the rotating spinner table 6a to clean the workpiece W, dry air is blown instead of the cleaning water to dry the workpiece W. ..

The chuck table 3 is formed with a holding surface 3a that sucks and holds the workpiece W by a porous ceramic material. The holding surface 3a is connected to a suction source (not shown) through a flow path in the chuck table 3. Four clamp portions 3b are provided around the chuck table 3, and each clamp portion 3b sandwiches and fixes the ring frame F around the workpiece W from all sides. The chuck table 3 is supported on the upper surface of the moving plate 10 via a θ table (not shown). The moving plate 10 is arranged in a rectangular opening 11 formed on the upper surface side of the base 2 and extending in the X direction. The opening 11 is covered with a moving plate 10 and a bellows-shaped waterproof cover 12 provided on both sides of the moving plate 10 in the X direction. Below the waterproof cover 12, a cutting feed means (not shown) for driving the chuck table 3 in the X direction, which is the cutting direction, is provided. This cutting feed means includes, for example, a ball screw type moving mechanism.

The cutting mechanism 4 is a cutting that is movably supported in the Y direction and the Z direction by the gate-shaped pillar portion 14 fixed on the base 2, the feeding means 15 provided on the pillar portion 14, and the feeding means 15. It has means 40.

The feeding means 15 has a pair of guide rails 21 parallel to the front surface of the pillar portion 14 in the Y direction, and a motor-driven Y-axis table 22 slidably installed on the pair of guide rails 21. .. Further, the feeding means 15 includes a pair of guide rails 23 parallel to the Z direction arranged on the front surface of the Y-axis table 22, and a motor-driven Z-axis table 24 slidably installed on each guide rail 23. are doing. A cutting means 40 is provided at the lower part of the Z-axis table 24.

Nut portions (not shown) are formed on the back surface side of the Y-axis table 22, and a ball screw 25 is screwed into these nut portions. Further, nut portions (not shown) are formed on the back surface side of each Z-axis table 24, and a ball screw 26 is screwed into these nut portions. A drive motor 28 (the drive motor of the ball screw 25 is not shown) is connected to one end of the ball screw 25 for the Y-axis table 22 and the ball screw 26 for the Z-axis table 24, respectively. The ball screws 25 and 26 are rotationally driven by the drive motor 28, and the cutting means 40 is moved in the Y and Z directions along the guide rails 21 and 23.

The cutting means 40 is configured by rotatably mounting a cutting blade 42 on the tip of a spindle (not shown) protruding from the spindle housing (housing) 41. The cutting blade 42 is surrounded by a blade cover 43 that forms a part of the housing 41. The cutting means 40 cuts the workpiece W by relatively moving the workpiece W and the cutting blade 42 in the X direction while rotating the cutting blade 42 at high speed.

Here, the cutting apparatus 1 is further provided with a cleaning mechanism 30 provided around the chuck table 3 for cleaning the workpiece W being machined. Hereinafter, the configuration of the cleaning mechanism 30 will be described with reference to FIG. FIG. 2 is a schematic vertical sectional view around the chuck table according to the present embodiment.

As shown in FIGS. 1 and 2, the cleaning mechanism 30 includes a water storage tank 31 that receives the chuck table 3 and a cutting water supply means 33 for filling the inside of the water storage tank 31 with cutting water P (not shown in FIG. 1). And have. The water storage tank 31 includes a square bottom wall 35 provided on the lower surface side of the chuck table 3 and a side wall 36 that stands upright from the outer periphery of the bottom wall 35 and surrounds the chuck table 3 from all sides. The upper part of 36 is opened and the lower part is closed by the bottom wall 35. Further, the upper end position of the side wall 36 is formed higher than the upper surface of the chuck table 3 and higher than the upper surface of the workpiece W held by the chuck table 3. The water storage tank 31 has a bottomed container shape and can store (store) cutting water P inside the side wall 36. By storing the cutting water P, the chuck table 3 and the workpiece W held on the chuck table 3 are stored. And can be submerged.

A cutting water supply source 38 is connected to the cutting water supply means 33, and the cutting water P is supplied so as to fill the inside of the water storage tank 31 with the cutting water P. The cutting water supply means 33 is provided above the side wall 36 on the + X direction side of the water storage tank 31 and at the center of the side wall 36 in the Y direction. The cutting water supply means 33 includes nozzles and the like arranged at the above-mentioned positions via columns and the like (not shown) provided on the moving plate 10 (not shown in FIG. 2). When the cutting water P is discharged from the cutting water supply means 33, the cutting water P flows in the water storage tank 31 from the + X direction side to the −X direction as shown by the alternate long and short dash line in FIG. The discharge of the cutting water P from the cutting water supply means 33 is set to a discharge pressure that forms the above-mentioned flow of the cutting water P but does not vibrate the cutting blade 42 due to the discharge.

Here, the bottom wall 35 of the water storage tank 31 is provided with drainage ports 39a and 39b (not shown in FIG. 2) at two positions in order to discharge the cutting water P in the water storage tank 31. One drain port 39a is provided on the opposite side of the cutting water supply means 33 with the chuck table 3 in the X direction. The other drain port 39b is formed at a position that becomes the same as the position where one drain port 39a is arranged before the rotation when the water storage tank 31 is rotated 90 degrees at the center position of the chuck table 3. There is. The drainage ports 39a and 39b are provided with a valve mechanism (not shown) such as a solenoid valve for controlling the opening and closing of the drainage ports 39a and 39b. Is opened, and the drainage port 39b that is not located is closed.

Subsequently, the cutting means of the present embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a diagram schematically showing a cross section and the like of the cutting means of the present embodiment. FIG. 4 is an exploded perspective view of the cutting means of the present embodiment. In addition, in FIG. 3 and FIG. 4, the wheel cover is omitted for convenience of explanation. Further, the cutting means may be configured as long as it is equipped with an elastic wave detection sensor described later, and is not limited to the configuration shown in FIGS. 3 and 4.

As shown in FIGS. 3 and 4, the cutting means 40 includes a spindle housing 41 fixed to the bottom of the Z-axis table 24 (see FIG. 1). The spindle housing 41 includes a housing body 44 and a cylindrical housing cover 45 mounted on one end side of the housing body 44.

Inside the housing body 44, a spindle (rotary spindle) 46 that rotates around the Y axis is housed. The spindle 46 is, for example, an air spindle, which is rotatably supported in a floating state with respect to the housing body 44 via a compressed air layer. The tip portion 46a of the spindle 46 projects from the housing body 44.

A circular opening 45a is formed in the center of the housing cover 45. Further, a locking portion 45c in which a hole 45b is formed is provided on the housing body 44 side of the housing cover 45. If one end side of the spindle 46 is inserted into the opening 45a and the screw 48 (not shown in FIG. 4, see FIG. 3) is tightened into the screw hole 44a of the housing body 44 through the screw hole 45b of the locking portion 45c, the housing cover 45 Can be fixed to the housing body 44.

A screw hole 46b is formed on the tip surface of the spindle 46. A fixed flange 50 is attached to the tip portion 46a of the spindle 46. The fixed flange 50 has a cylindrical boss portion 51 and a flange-shaped mounting portion 52 extending radially outward from the peripheral surface of the boss portion 51.

An opening 50a penetrating the boss portion 51 is formed in the center of the fixed flange 50. The tip portion 46a of the spindle 46 is fitted into the opening 50a from the back surface side (spindle housing 45 side). In this state, the washer 54 is positioned in the opening 50a, and the fixing bolt 55 is screwed into the screw hole 46b through the washer 54, so that the fixing flange member 50 is fixed to the spindle 46.

The cutting blade 42 is a hub blade in which an annular cutting edge 58 is attached to the outer circumference of a substantially disk-shaped hub base 57, and is inserted into a boss portion 51 of a fixed flange 50 at the center of the hub base 57. An insertion hole 59 is formed. The cutting edge 58 is formed to have a predetermined thickness by mixing abrasive grains such as diamond and CBN (Cubic Boron Nitride) with a bond material (bonding material) such as metal or resin. As the cutting blade 42, a washer blade composed of only a cutting edge may be used.

When the insertion hole 59 of the hub base 57 is pushed into the boss portion 51, the boss portion 51 protrudes from the hub base 57. A male screw 51a is formed on the outer peripheral surface of the protruding portion of the boss portion 51, and an annular fixing nut 61 is tightened to the male screw 51a to fix the cutting blade 42 to the fixing flange 50. In this way, the fixed flange 50 is attached to the tip of the spindle 46, and the cutting blade 42 is further attached to the fixed flange 50.

When the workpiece W (see FIG. 1) is cut by the cutting blade 42 that rotates at high speed, an elastic wave is generated in the cutting blade 42, and the elastic wave detection sensor 64 that detects the generated elastic wave is the cutting means 40. It is arranged in.

The elastic wave detection sensor 64 is composed of, for example, an AE sensor (acoustic emission sensor) having a function of detecting elastic waves. The AE sensor detects elastic waves emitted during cutting of the workpiece W by the rotating cutting blade 42 as acoustic waves, and the acoustic waves at that time are small deformations and minute cracks even before the solid is destroyed. Since it occurs as it occurs and progresses, it is possible to discover and predict defects and fractures in materials and structures.

The elastic wave detection sensor 64 includes an ultrasonic vibrator 66 fixed inside the fixed flange 50. The ultrasonic vibrator 66 includes, for example, barium titanate (BaTIO ₃ ), lead zirconate titanate (Pb (Zi, Ti) O ₃ ), lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO ₃ ), and the like. It is made of the above material and converts the vibration of the cutting blade 42 into a voltage (vibration signal). The ultrasonic vibrator 66 may resonate with vibration of a predetermined frequency, and the frequency of vibration that can be detected by the elastic wave detection sensor 64 may be determined according to the resonance frequency. In this case, ultrasonic vibrators 66 having different resonance frequencies may be provided on the plurality of fixed flanges 50, and any one of the fixed flanges 50 may be appropriately selected and used according to the processing conditions and the like.

The elastic wave detection sensor 64 includes a first coil means 67 provided on the fixed flange 50 and connected to the ultrasonic vibrator 66, and a second coil means 67 provided on the housing cover 45 and facing the first coil means 67. Includes coil means 68. As the first coil means 67 and the second coil means 68, an annular coil in which a conducting wire is wound can be exemplified.

The first coil means 67 and the second coil means 68 are magnetically coupled, and the voltage generated by the ultrasonic vibrator 66 is mutual to the first coil means 67 and the second coil means 68. By induction, it is transmitted to the second coil means 68 side.

As shown in FIG. 3, the control means 80 is connected to the second coil means 68 via the signal processing unit 81. The signal processing unit 81 includes an amplifier or the like that converts an output signal detected by the elastic wave detection sensor 64 into an output voltage. Therefore, the output signal detected by the elastic wave detection sensor 64 is input to the control means 80 as an output signal (output voltage or the like) converted by the signal processing unit 81.

The control means 80 comprehensively controls each part of the device including the feed means 15, the cutting feed means (not shown), and the cutting means 40 in response to the output signal from the elastic wave detection sensor 64. The control means 80 includes a processor, a memory, and the like that execute various processes. The memory is composed of one or a plurality of storage media such as ROM (Read Only Memory) and RAM (Random Access Memory) depending on the intended use.

Next, with reference to FIG. 2, a method of cutting the workpiece W by the cutting device 1 will be described. First, the workpiece W fixed to the ring frame F via the dicing tape T is conveyed to the chuck table 3 as a unit by a conveying means (not shown) and is sucked and held. Further, the ring frame F is fixed by the clamp portion 3b around the chuck table 3. Next, after aligning the workpiece W, the chuck table 3 is moved in the X direction to position the workpiece W closer to the lower part of the cutting blade 42 which is the cutting region. Further, the cutting blade 42 is moved and positioned in the Y-axis direction according to the planned division line of the workpiece W.

After positioning as described above, the cutting water P is supplied from the cutting water supply source 38 to the water storage tank 31 through the cutting water supply means 33. The cutting water P is supplied so as to fill the opening at the upper end of the side wall 36 of the water storage tank 31, and the workpiece W held on the chuck table 3 by the cutting water P is submerged. While the cutting water P is being supplied from the cutting water supply means 33, substantially the same amount or a smaller amount as the supplied cutting water P is discharged as drainage at the drain port 39a.

After that, the cutting blade 42 rotated at high speed is lowered and positioned in the Z direction according to the cutting depth of the workpiece W. After this positioning, the chuck table 3 is relatively moved in the X direction with respect to the cutting blade 42, and the cutting groove is cut along the planned division line of the workpiece W in a submerged state in which the cutting water P is stored in the water storage tank 31. To do. Then, every time one cutting groove is formed, the cutting blade 42 is moved in the Y direction by the pitch interval in the Y direction of the planned division line, and the same operation is repeated to sequentially form the cutting groove.

Cutting chips are generated by cutting with the cutting blade 42, but since the workpiece W is submerged in the cutting water P, the cutting chips are suspended from the upper surface of the workpiece W to prevent adhesion to the workpiece W. be able to. At this time, a water flow from the right to the left (X direction) in FIG. 2 can be formed in the water storage tank 31 by discharging the cutting water P from the cutting water supply means 33 and discharging the cutting water P from the drain port 39a. As a result, the cutting water P passes through the upper surface of the workpiece W, and the workpiece W is cut while flowing the upper surface of the workpiece W with the cutting water P.

After forming cutting grooves in all the planned division lines parallel to the X-axis, the chuck table 3 and the water storage tank 31 are rotated by 90 ° via a θ table (not shown), and the same cutting as above is performed to perform all divisions. A cutting groove is formed in the planned line, and the workpiece W is cut vertically and horizontally. After rotating the chuck table 3 and the water storage tank 31 by 90 °, the drain port 39b (see FIG. 1) and the cutting water supply means 33 are located so as to sandwich the chuck table 3, and the flow of the cutting water P continues even after the rotation. Can be produced in the same manner as described above.

Here, when the workpiece W is cut by the cutting means 40, when the workpiece W comes into contact with the cutting edge 58 of the rotating cutting blade 42, an elastic wave is generated in the cutting blade 42. The elastic wave propagates to the elastic wave detection sensor 64 located in the vicinity of the cutting blade 42, and the elastic wave detection sensor 64 detects the propagated elastic wave and outputs an output signal to the control means 80. The control means 80, for example, spectrally analyzes a waveform (waveform in the time domain) corresponding to a time change of a voltage transmitted per arbitrary unit time by a Fourier transform (for example, a fast Fourier transform), and obtains a frequency. The state of the cutting blade 42 is determined based on the waveform of the region. The unit time is the time required to cut one line (for each cut line), the time required for cutting one workpiece (for each work), and the time required to cut an arbitrary distance (cut). Various modes such as (for each distance) can be considered.

FIG. 5A is a graph showing an example of a voltage waveform (waveform in the time domain) transmitted to the control means, and FIG. 5B is a graph showing an example of a waveform (waveform in the frequency domain) after Fourier transform. In FIG. 5A, the vertical axis represents voltage (V), the horizontal axis represents time (t), and in FIG. 5B, the vertical axis represents amplitude and the horizontal axis represents frequency (f).

In this way, if the waveform of the voltage (vibration signal) from the elastic wave detection sensor 64 is Fourier-transformed by the control means 80, as shown in FIG. 5B, the vibration of the cutting blade 42 is divided into the main frequency components and cut. Abnormalities that occur inside can be easily analyzed. As a result, abnormalities during cutting can be detected accurately in real time.

FIG. 5C is a graph showing an example of a waveform (waveform in the frequency domain) before and after the occurrence of an abnormality. In FIG. 5C, the vertical axis represents the amplitude and the horizontal axis represents the frequency (f). Further, in FIG. 5C, the waveform before the occurrence of the abnormality is shown by a solid line, and the waveform after the occurrence of the abnormality is shown by a broken line.

As shown in FIG. 5C, the waveform after the occurrence of the abnormality has a vibration mode (vibration component) on the high frequency side, which is not seen in the waveform before the occurrence of the abnormality. For example, the control means 80 compares the waveforms (waveforms in the frequency domain) before and after the occurrence of the abnormality, and determines that the abnormality corresponding to the vibration mode observed only in the waveform after the occurrence of the abnormality has occurred.

Here, conventionally, in order to determine whether or not there is an abnormality in the cutting blade, even when detecting the vibration of the cutting blade during machining, cutting water is injected from the nozzle to the cutting position at high pressure for the convenience of cooling and cleaning. While cutting was being carried out. Therefore, vibration is generated by the energy when the injected cutting water is sprayed on the workpiece or the cutting blade, and this vibration also has to be detected by the elastic wave detection sensor. Therefore, in the detection of elastic waves emitted from the cutting blade by cutting, the injection of cutting water becomes noise, and it is difficult to properly collect the vibration of the cutting blade.

On the other hand, in the cutting device 1 of the present embodiment, since the cutting process is performed with the workpiece W submerged inside the water storage tank 31, it is not necessary to inject the cutting water P from the nozzle at high pressure. As a result, noise can be reduced in the detection of elastic waves by the elastic wave detection sensor 64, and the elastic waves generated by cutting the cutting blade 42 can be appropriately collected. Since the influence of noise due to the cutting water P is reduced in this way, the elastic wave detection sensor 64 composed of the AE sensor can accurately capture the change in the elastic wave and accurately determine the abnormality of the cutting blade 42 and the like. ..

The elastic wave detection sensor 64 may be installed at another position of the cutting means 40, and as shown in FIG. 6, it can be exemplified that the elastic wave detection sensor 64 is provided on the wheel cover 43 that covers the outer periphery of the cutting blade 42. FIG. 6 is a schematic cross-sectional view of the cutting means and the chuck table of the modified example. The wheel cover 43 of the cutting means 40 of FIG. 6 has a configuration in which a support 43a is provided on the + X direction side, which is the cutting feed direction, and an elastic wave detection sensor 64 is supported on the lower end side of the support 43a.

The elastic wave detection sensor 64 is arranged close to the front side (+ X direction) of the cutting blade 42 via the support 43a. Further, the Z-direction position of the elastic wave detection sensor 64 is a position where the elastic wave detection sensor 64 is submerged in the cutting water P in the water storage tank 31 at the time of cutting, and is positioned so as not to contact the workpiece W. .. As a result, the elastic wave during machining by the cutting blade 42 can be appropriately detected through the cutting water P by the elastic wave detection sensor 64. Further, since the elastic wave detection sensor 64 is provided in front of the cutting blade 42, the elastic wave can be detected by making it less susceptible to the influence of the cutting water P scattered by the rotation of the cutting blade 42.

Further, the control means 80 may analyze without Fourier transform. For example, the output range and output value of the output signal of the elastic wave detection sensor 64 immediately before the occurrence of an abnormality are stored in advance as a threshold value and compared with this threshold value. Then, the situation of the cutting blade 42 may be analyzed.

Further, the configuration of the cleaning mechanism 30 can be variously changed as long as the cutting water P can be stored in the water storage tank 31 and cut in a submerged state as in the above embodiment. For example, the water tank 31 may have a circular shape in a plan view, or the side wall 36 may be movable so that drainage can be performed.

Further, in the present embodiment, the cutting device 1 for dividing the workpiece W is illustrated, but the cutting device 1 may be used not only for dividing but also for edge trimming of the workpiece W.

Further, the embodiment of the present invention is not limited to the above-described embodiment and modification, and may be variously modified, replaced, or modified without departing from the spirit of the technical idea of the present invention. Furthermore, if the technical idea of the present invention can be realized in another way by the advancement of technology or another technology derived from it, it may be carried out by using that method. Therefore, the scope of claims covers all embodiments that may be included within the scope of the technical idea of the present invention.

As described above, the present invention has the effect of being able to appropriately collect elastic waves generated when cutting with a cutting means, and in particular, a cutting apparatus that cuts a workpiece with a rotating cutting blade. It is useful for.

1 Cutting device 3 Chuck table (holding means)
31 Water tank 33 Cutting water supply means 40 Cutting means 41 Spindle housing (housing)
42 Cutting blade 43 Spindle (rotary spindle)
64 Elastic wave detection sensor 80 Control means P Cutting water W Work piece

Claims (1)

In a cutting apparatus including at least a holding means for holding a work piece and a cutting means having a cutting blade for cutting the work piece held by the holding means.
A water storage tank that stores the work piece held on the chuck table of the holding means in a submerged state, and a cutting water supply means that supplies cutting water to the water storage tank.
It is provided with an elastic wave detection sensor which is arranged in the cutting means and detects an elastic wave generated when the workpiece is cut by the cutting means.
The work piece held on the holding means is in a submerged state in which the cutting water is stored in the water storage tank, and a part including the cutting portion is immersed in the cutting water of the water storage tank, and the part is different from the part. cutting apparatus characterized by being cut by the cutting blade has a region exposed in part from the cutting water該貯aquarium.

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