JP7383346B2 - Measuring method - Google Patents

Description

The present invention relates to a measurement method for forming a cutting groove in a workpiece by cutting the workpiece with a cutting blade, and then measuring the size of chipping formed at the edge of the cutting groove due to cutting.

Semiconductor device chips with functions such as LEDs (Light Emitting Diodes), chip resistors, surface acoustic wave filters, and IGBTs (Insulated Gate Bipolar Transistors) are used in electronic devices such as mobile phones and electrical devices such as motors. .

These semiconductor device chips are manufactured using ceramic substrates such as alumina substrates and alumina-zirconia substrates so as to have predetermined performance in various properties such as heat resistance, insulation, and heat dissipation.

For example, after forming multiple semiconductor devices on one ceramic substrate, the ceramic substrate is cut and divided using a cutting device equipped with a cutting blade, thereby dividing one ceramic substrate into multiple semiconductor device chips ( For example, see Patent Document 1).

However, when a ceramic substrate is cut with a cutting blade, chipping (that is, chipping) occurs at the outer periphery of the semiconductor device after cutting due to processing conditions and the like. A semiconductor device chip having a chipping size larger than a predetermined tolerance value has a lower bending strength than a semiconductor device chip having a chipping size smaller than the tolerance value, and is treated as a defective product.

Therefore, it is necessary to evaluate the magnitude of chipping formed on a semiconductor device chip. For this reason, after forming a cutting groove (kerf) on the surface side of a ceramic substrate, the size of chipping formed at the edge of the cutting groove due to cutting is evaluated.

As a method for evaluating the size of chipping, visual evaluation using an optical microscope is usually performed. However, in the case of a ceramic substrate (particularly a white substrate made of alumina or the like), light is diffusely reflected on the surface side of the substrate, making it difficult to evaluate the size of chipping.

Japanese Unexamined Patent Publication No. 4-179505

Therefore, currently, after cutting a ceramic substrate for processing tests, the edges of the cut grooves are colored with an oil-based marker to suppress diffused reflection of light, and then the size of chipping is evaluated.

The present invention has been made in view of the above problems, and it is an object of the present invention to more easily measure the size of chipping without coloring the edges of cut grooves.

According to one aspect of the present invention, after a cutting groove is formed in the workpiece by cutting the workpiece with a rotating cutting blade, the size of chipping formed at the edge of the cutting groove due to cutting is The method includes a reflected wave detection step of injecting an ultrasonic wave into the edge of the cutting groove and detecting a reflected wave reflected from the edge, and a step of detecting a reflected wave in advance according to the reflected wave. a conversion step of converting the reflected wave into image data based on a set color tone; and a conversion step of converting the reflected wave into image data based on the set color tone; a measurement step of measuring the size, and the reflected wave detection step uses an ultrasonic probe and a liquid supply nozzle whose positions are respectively fixed with respect to the cutting unit to which the cutting blade is attached, With a liquid being supplied from the liquid supply nozzle between the ultrasonic probe and the workpiece, ultrasonic waves are made to enter the edge of the cutting groove from the ultrasonic probe, and the A measurement method is provided for detecting the reflected wave reflected from the edge with an ultrasonic probe .

Preferably, in the conversion step, the reflected wave is converted into the image data based on a color tone set depending on the intensity of the reflected wave.

Preferably, the reflected wave detection step includes repeatedly performing the operation of detecting reflected waves by injecting ultrasonic waves at a plurality of positions across the cut groove along the longitudinal direction of the cut groove.

In the measurement method according to one aspect of the present invention, an ultrasonic wave is made incident on a measurement region including the edge of a cut groove, and a reflected wave reflected from the measurement region is detected (reflected wave detection step). Then, the reflected wave is converted into image data based on a color tone set in advance according to the reflected wave (conversion step).

Furthermore, the size of chipping formed in the cut groove is measured from the image data or an image created from the image data (measuring step). In this way, the edges can be observed by visualizing the cut grooves using ultrasound. Therefore, the size of chipping can be measured more easily without coloring the edges of the cut grooves.

1 is a diagram illustrating a configuration example of an ultrasonic imaging device and the like. It is a perspective view showing a cutting device etc. FIG. 3(A) is a partially enlarged view of the cut groove, and FIG. 3(B) is a partially enlarged view of the cut groove for explaining the area to which ultrasonic waves are irradiated. FIG. 4(A) is a graph showing an example of reflected waves, FIG. 4(B) is a graph showing another example of reflected waves, and FIG. 4(C) explains the correspondence between amplitude and color tone. It is a diagram. FIG. 5(A) is an example of an image on the front side, and FIG. 5(B) is an example of an image on the front side when an optical microscope is used. FIG. 3 is a flow diagram of a method for measuring chipping. It is a perspective view showing a cutting device concerning a 2nd embodiment. FIG. 7 is a partially cross-sectional side view showing a reflected wave detection process according to the second embodiment.

Embodiments according to one aspect of the present invention will be described with reference to the accompanying drawings. First, the ultrasonic imaging device 2 for imaging chipping will be described. FIG. 1 is a diagram showing an example of the configuration of an ultrasonic imaging device 2 and the like. Note that in FIG. 1, some of the constituent elements are shown in a block diagram.

The configuration of the ultrasound imaging device 2 is substantially the same as a commercially available ultrasound imaging device. An ultrasound probe 4 is connected to the ultrasound imaging device 2 . The ultrasonic probe 4 includes, for example, a PMUT (Piezoelectric Micromachined Ultrasonic Transducer) having a piezo element.

A horizontal movement mechanism (not shown) for horizontally moving the ultrasound probe 4 is connected to the ultrasound probe 4 . The horizontal movement mechanism is, for example, an XY scanner, and moves the ultrasound probe 4 along the X-axis direction and the Y-axis direction perpendicular to the X-axis direction in a predetermined plane.

A transmitting unit 8 is connected to the ultrasound probe 4 via a transmitting/receiving switching unit 6 . The transmission/reception switching unit 6 has a predetermined circuit for switching the electrical connection between the ultrasound probe 4 and the transmission unit 8 or the reception unit 10.

The transmitting unit 8 has a signal generator (not shown) that generates a voltage signal. The signal generator transmits a voltage signal whose voltage value, frequency, etc. are adjusted to predetermined values to the ultrasound probe 4 via the transmission/reception switching unit 6 .

When the ultrasound probe 4 and the transmission unit 8 are electrically connected and a predetermined voltage signal is transmitted from the transmission unit 8 to the ultrasound probe 4, the piezo element vibrates and generates a pulsed signal. Ultrasonic waves are generated.

At a predetermined timing after the generation of ultrasound, the transmission/reception switching unit 6 releases the electrical connection between the ultrasound probe 4 and the transmission unit 8, and disconnects the ultrasound probe 4 and the reception unit 10 from each other. connected to.

The ultrasonic probe 4 emits pulsed ultrasonic waves that are reflected by a workpiece 11, which will be described later, and then receives reflected waves (echoes), scattered waves, etc. from the workpiece 11 (pulse echo). law). The reflected wave is converted into a voltage signal by the piezo element and transmitted to the receiving unit 10.

The receiving unit 10 includes an analog-to-digital converter (ADC) that converts an analog voltage signal converted by a piezo element into a digital signal at a predetermined sampling frequency.

The receiving unit 10 is connected to an image conversion processing unit 12. In the image conversion processing unit 12, the color tone of the pixel to be converted is set in advance in accordance with the intensity or frequency of the reflected wave.

The image conversion processing unit 12 converts the digital signal received from the receiving unit 10 into image data by converting information on the intensity or frequency of the reflected wave into information on the color tone of the pixel. The image data has vertical and horizontal position information and pixel values determined according to each position information, and is data used when configuring one image.

The image data may be in any format such as JPEG (Joint Photographic Experts Group), GIF (Graphics Interchange Format), PNG (Portable Network Graphics), or TIFF (Tagged Image File Format).

The image conversion processing unit 12 further performs image processing on the image data. For example, the image conversion processing unit 12 performs processing such as known edge detection on the image data, and then calculates the size of the chipping 15b formed on the edge 15a of the cutting groove 15.

The size of the chipping 15b is, for example, the maximum length of the chipping 15b extending from the edge of the cutting groove 15 to the outside of the cutting groove 15 along the width direction of the cutting groove 15 when there is no chipping 15b. Note that the position of the edge of the cutting groove 15 is also specified by image processing.

Image conversion processing unit 12 is connected to a display device 14, such as a video monitor, computer screen, or the like. The display device 14 may be a display-only monitor or screen, or may be a touch panel or touch screen capable of display and input.

The image data created by the image conversion processing unit 12 is displayed on the display device 14. The ultrasonic imaging device 2 further includes a control unit 16 that controls operations of the transmission/reception switching unit 6, the transmission unit 8, the reception unit 10, the image conversion processing unit 12, and the like.

The control unit 16 includes, for example, a processing device such as a processor represented by a CPU (Central Processing Unit), and a main memory such as a DRAM (Dynamic Random Access Memory), an SRAM (Static Random Access Memory), or a ROM (Read Only Memory). The computer includes a device and an auxiliary storage device such as a flash memory, hard disk drive, or solid state drive.

The functions of the control unit 16 are realized by operating the processing device and the like according to software stored in the auxiliary storage device. Note that the control unit 16 may be configured using an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or the like.

The control unit 16 is connected to an input device 18 including a plurality of input buttons and a touch panel on which a GUI (Graphical User Interface) is displayed. Various conditions regarding the ultrasound imaging device 2 are set in the control unit 16 via the input device 18 .

For example, using the input device 18, the magnitude and frequency of the voltage signal output by the transmitting unit 8 are set. Further, for example, using the input device 18, the color tone of the pixel corresponding to the intensity or frequency of the reflected wave is set.

The cut groove 15 formed on the surface 11a side of the workpiece 11 is imaged using the ultrasonic imaging device 2 described above. The workpiece 11 is, for example, a ceramic substrate for manufacturing piezoelectric elements. As ceramic substrates for manufacturing piezoelectric elements, lead-containing substrates and lead-free (lead-free) substrates are known.

The lead-containing substrate is made of, for example, PZT (lead zirconate titanate) or PMN-PT (lead magnesium niobate-lead titanate). Further, the lead-free substrate is formed of barium titanate, sodium bismuth titanate, potassium bismuth titanate, or bismuth zincate vanadate.

The workpiece 11 may be a ceramic substrate without a piezoelectric element. Ceramic substrates without piezoelectric elements include alumina substrates, zirconia substrates, alumina zirconia substrates, aluminum nitride substrates, silicon nitride substrates, HTCC (High Temperature Cofired Multilayer Ceramics) substrates (i.e., high temperature fired ceramic multilayer substrates), and LTCC (Low Temperature Ceramics). Cofired multilayer ceramics (low-temperature firing ceramics multilayer substrate), etc.

Further, the workpiece 11 may be a semiconductor substrate such as silicon (Si), silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga ₂ O ₃ ), gallium arsenide (GaAs), or the like. A cutting groove 15 is formed on the surface 11a side of the workpiece 11 using a cutting device 20. FIG. 2 is a perspective view showing the cutting device 20 and the like. The cutting device 20 includes a chuck table 24 that holds the workpiece 11 and the like.

The upper surface of the chuck table 24 is formed substantially parallel to a plane defined by the X-axis direction (processing feed direction) and the Y-axis direction (indexing feed direction). The upper surface of the chuck table 24 is connected to a suction source (not shown) such as an ejector via a suction path (not shown) formed inside the chuck table 24 .

When the suction source is operated, negative pressure is generated on the upper surface of the chuck table 24, so the upper surface functions as a holding surface for holding the workpiece 11 and the like. A workpiece 11 is placed on the holding surface via a circular dicing tape 17 made of resin in the form of a workpiece unit 21 supported by an annular frame 19 made of metal.

A plurality of clamps (not shown) are provided around the chuck table 24 to grip and fix the annular frame 19. Furthermore, a rotation mechanism (not shown) having a motor or the like that rotates the chuck table 24 around a rotation axis that is generally parallel to the Z-axis direction (vertical direction, vertical direction) is provided at the lower part of the chuck table 24. .

Furthermore, a ball screw-type X-axis direction moving mechanism (not shown) for moving the chuck table 24 along the X-axis direction is provided at the bottom of the rotation mechanism. Further, above the chuck table 24, a cutting unit 26 for cutting the workpiece 11 is arranged.

The cutting unit 26 includes a cylindrical spindle housing 28. The spindle housing 28 is arranged such that the height direction of the cylinder is substantially parallel to the Y-axis direction. A portion of a cylindrical spindle (not shown) is accommodated within the spindle housing 28 .

One end of the spindle is exposed outside the spindle housing 28, and an annular cutting blade 30 is attached to this one end. The cutting blade 30 may be a so-called hub type blade in which a cutting edge is provided on the outer periphery of a circular base made of metal such as aluminum, or a so-called hubless type blade in which both sides are held between a mount and a holding nut. (washer type) blade, etc.

A rotational drive source (not shown) such as a servo motor is connected to the other end of the spindle located on the opposite side from the one end of the spindle. The cutting blade 30 is rotated by power transmitted from the rotational drive source via the spindle.

The spindle housing 28 is provided with a camera unit (not shown) that images a subject using visible light. The camera unit has an objective lens (not shown) and an imaging lens (not shown) that constitute an optical microscope.

The camera unit further includes an image sensor (not shown) such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor for capturing an image of a subject through an objective lens and an imaging lens. .

A Z-axis moving plate (not shown) of a ball screw type Z-axis moving mechanism (not shown) is connected to the spindle housing 28 . Further, a Y-axis moving plate (not shown) of a ball screw type Y-axis moving mechanism (not shown) is connected to the Z-axis moving mechanism. The cutting unit 26 moves along the Z-axis direction by a Z-axis direction movement mechanism, and moves along the Y-axis direction by a Y-axis direction movement mechanism.

Next, a method for measuring chipping 15b (see FIG. 1) according to the first embodiment will be described. FIG. 6 is a flow diagram of a method for measuring chipping 15b according to the first embodiment. In the method for measuring chipping 15b, first, cutting groove 15 is formed in workpiece 11 using cutting device 20, and then the size of chipping 15b formed on edge 15a of cutting groove 15 is measured.

When cutting the workpiece 11, first, the back side 11b side of the workpiece 11 (that is, the dicing tape 17 side of the workpiece unit 21) is held by suction with the holding surface, and a plurality of annular frames 19 are cut. (holding step (S10)). At this time, the surface 11a of the workpiece 11 is exposed upward.

Next, the orientation of the workpiece 11 is adjusted using the camera unit so that the line to be machined on the workpiece 11 is approximately parallel to the cutting blade 30 . The orientation of the workpiece 11 is realized by rotating the chuck table 24.

Thereafter, the cutting blade 30 is rotated at high speed with the cutting blade 30 disposed outside the planned processing line, and the lower end of the cutting blade 30 is positioned at a predetermined depth position from the surface 11a of the workpiece 11. Then, the chuck table 24 is moved in the X-axis direction relative to the cutting blade 30.

Thereby, the workpiece 11 is cut along the line to be machined. A linear cutting groove 15 having a width of, for example, 100 μm is formed on the surface 11a side (cutting step (S20)). In the example shown in FIGS. 1 and 2, the workpiece 11 is not completely cut in the thickness direction, but may be completely cut.

Further, after forming one cutting groove 15 along the X-axis direction, the cutting unit 26 is indexed and fed to cut an area different from the one cutting groove 15, thereby forming a plurality of cutting grooves 15. You can.

For example, if a plurality of cutting grooves 15 are formed with different cutting conditions, the correlation between the cutting conditions and the size of chipping 15b can be evaluated. Furthermore, by forming a plurality of cutting grooves 15, it is also possible to evaluate the correlation between the wear of the cutting blade 30 and the chipping 15b.

FIG. 3(A) is a partially enlarged view of the cutting groove 15 formed on the surface 11a side. A plurality of chippings 15b are formed on the edge 15a of the cutting groove 15 on the surface 11a side so as to extend outward from the edge of the cutting groove 15.

In order to image these chippings 15b, the surface 11a side is imaged with the ultrasonic imaging device 2. To do this, first, the workpiece 11 is peeled off from the dicing tape 17, and as shown in FIG. do.

At this time, the entire workpiece 11 is immersed in the liquid 32, and the surface 11a faces the lower end of the ultrasonic probe 4 at a predetermined distance from the lower end of the ultrasonic probe 4. In this state, ultrasonic waves are made to enter the edge 15a of the cut groove 15 on the surface 11a side from the ultrasonic probe 4 via the liquid 32, and the reflected waves are detected by the ultrasonic probe 4 (reflected waves Detection step (S30)).

FIG. 3(B) is a partially enlarged view of the cutting groove 15 illustrating the area to which ultrasonic waves are irradiated. In the reflected wave detection step (S30) of this embodiment, a predetermined frequency of 25 MHz or more and 200 MHz or less, which is the wavelength band of ultrasonic waves, is used.

When detecting reflected waves, first adjust the distance from the lower end of the ultrasound probe 4 to the surface 11a, and adjust the distance from the lower end of the ultrasound probe 4 so that the ultrasound waves converge on the surface 11a underwater. position. Also, at this time, the lower end of the ultrasound probe 4 is positioned outside one of the edges 15a (indicated by a solid circle in FIG. 3(B)).

Then, the ultrasonic probe 4 emits ultrasonic waves, and the ultrasonic probe 4 detects reflected waves of the ultrasonic waves. Next, using the above-mentioned horizontal movement mechanism, the ultrasonic probe 4 is moved inside the cutting groove 15 along the width direction of the cutting groove 15, for example, by a length of 1/10 or less of the width of the cutting groove 15. The device is moved a predetermined distance corresponding to , and similarly emits ultrasonic waves and detects reflected waves.

Similarly, reflected waves are detected at each position moved a predetermined distance along the width direction of the cutting groove 15. This operation is repeated to irradiate ultrasonic waves at a plurality of positions across the cut groove 15 and detect reflected waves, as shown in FIG. 3(B). Note that the number of multiple positions is not limited to the example shown in FIG. 3(B).

In this embodiment, the work of detecting reflected waves of ultrasonic waves at a plurality of positions across the cut groove 15 is repeatedly performed along the longitudinal direction of the cut groove 15 . FIG. 4(A) is a graph showing an example of reflected waves.

FIG. 4(A) shows the first reflected wave measured by the pulse echo method. The horizontal axis is time, and the vertical axis is the amplitude (voltage value) of the signal received by the ultrasound probe 4, which corresponds to the intensity of the reflected wave. In this embodiment, attention is paid to the first received peak (peak P ₁ shown in FIG. 4A) among the plurality of peaks that constitute the first reflected wave.

When ultrasonic waves are irradiated on the relatively flat surface 11a, most of the incident waves are reflected and received by the ultrasonic probe 4. In this case, the amplitude of peak _P1 will be relatively large.

On the other hand, when the area where the chipping 15b is formed or the cutting groove 15 is irradiated with ultrasonic waves, the amplitude of the peak _P1 becomes relatively small due to scattering of specific frequency components of the incident wave ( (See Figure 4(B)).

In addition, bubbles tend to remain in the area where the chipping 15b is formed, and the bubbles invert the phase of a specific frequency component of the reflected wave, and the reflected wave is attenuated due to interference between the phase-inverted reflected wave and the incident wave. Sometimes I do. FIG. 4(B) is a graph showing another example of a reflected wave in which the amplitude of the peak _P1 is relatively small. The vertical axis and horizontal axis of FIG. 4(B) are the same as the example of FIG. 4(A).

The receiving unit 10 converts the received reflected wave (analog signal) into a digital signal. The converted digital signal is stored in a memory (not shown) connected to the image conversion processing unit 12.

The image conversion processing unit 12 accesses the memory after a plurality of digital signals corresponding to a predetermined number of reflected waves are stored. Then, the image conversion processing unit 12 converts the plurality of digital signals into image data based on a color tone that is preset according to the amplitude (i.e., intensity) of the reflected wave (conversion step (S40)). .

FIG. 4C is a diagram illustrating the correspondence between the amplitude (intensity) of a reflected wave and the tone of a pixel value. The color tone is specified by saturation and lightness, and the saturation may be either an achromatic color (white, gray, black, etc.) or a pure color.

In the example shown in FIG. 4C, achromatic colors are used for convenience. In this embodiment, the larger the amplitude, the higher the brightness of the pixel (ie, brighter), and the smaller the amplitude, the lower the brightness of the pixel (ie, darker). The brightness of a pixel corresponding to the amplitude is expressed, for example, in 256 tones from 0 to 255.

After scanning substantially the entire surface 11a side with the ultrasound probe 4, the image conversion processing unit 12 sends the image data on the surface 11a side to a driver circuit (not shown) of the display device 14. Thereby, the image created from the image data is displayed on the display device 14. FIG. 5(A) is an example of an image of the surface 11a side created by irradiating ultrasonic waves.

The image conversion processing unit 12 performs known image processing such as edge detection on the image data, and automatically measures the size of the chipping 15b (measuring step (S50)). For example, the image conversion processing unit 12 converts the coordinates of the pixel where the edge of the cutting groove 15 is located when there is no chipping 15b to the edge of the chipping 15b extending outside the cutting groove 15 along the width direction of the cutting groove 15. Specify the length to the coordinates of the located pixel.

Then, the distance between the coordinates is converted into an actual length. Thereby, the size of the chipping 15b is measured. The measured size (length) of the chipping 15b is displayed on the display device 14 together with the image, for example. Further, the size of the chipping 15b may be displayed on a monitor, screen, etc. different from the image displayed on the display device 14, or may be printed on paper or the like.

In addition, in the measurement step (S50), the size of the chipping 15b may be measured based on the image on the surface 11a side displayed on the display device 14. For example, a predetermined ruler (scale) may be displayed on the display device 14, and the operator may measure the size of the chipping 15b from the image.

In this embodiment, the edge 15a is observed by visualizing the cutting groove 15 using ultrasound. Therefore, the size of the chipping 15b can be measured more easily without coloring the edge 15a of the cutting groove 15. Moreover, the time required for measuring the chipping 15b can also be shortened.

FIG. 5(B) is an example of an image of the surface side when the cutting groove 15 formed on the surface 11a side is imaged using an optical microscope. Note that the display magnification in FIG. 5(B) is the same as the display magnification in FIG. 5(A).

Chipping 15b is also formed on the edge 15a of the cutting groove 15 in FIG. 5(B), as in the example shown in FIG. 5(A). However, since an optical microscope is used, the light is diffusely reflected on the surface 11a side of the workpiece 11, making it difficult to evaluate the size of the chipping 15b.

Next, a second embodiment will be described. In the second embodiment, a cutting device 20a in which an ultrasonic imaging device 2 and a cutting device 20 are integrated is used. Using the cutting device 20a, it is possible to scan the surface 11a side with the ultrasonic probe 4 while holding the workpiece 11 on the chuck table 24, and obtain an image of the surface 11a side.

FIG. 7 is a perspective view showing a cutting device 20a according to the second embodiment. One end of an arm 36 is fixed to the spindle housing 28 of the cutting device 20a. The above-mentioned ultrasonic probe 4 is fixed to the bottom of the other end of the arm 36.

Further, a liquid supply nozzle 38 is fixed to the bottom of the other end of the arm 36 at a position adjacent to the ultrasound probe 4 . A storage tank (not shown) storing a liquid such as pure water is connected to the liquid supply nozzle 38 via a water pump (not shown), a solenoid valve (not shown), or the like.

When the control unit 16 of the ultrasonic imaging device 2 opens the solenoid valve, a liquid such as pure water is supplied from the liquid supply nozzle 38. Next, a method for measuring chipping 15b according to the second embodiment will be described.

In the method for measuring chipping 15b according to the second embodiment, after the holding step (S10) and the cutting step (S20), the reflected wave detection step (S30) is performed without peeling the workpiece 11 from the dicing tape 17. . This point differs from the first embodiment.

FIG. 8 is a partially sectional side view showing the reflected wave detection step (S30) according to the second embodiment. In the reflected wave detection step (S30), first, the other end of the arm 36 is positioned above the cutting groove 15 of the workpiece 11. The position of the other end of the arm 36 is adjusted using the above-mentioned X-axis direction movement mechanism, Y-axis direction movement mechanism, and Z-axis direction movement mechanism.

Then, while the liquid 40 is supplied from the liquid supply nozzle 38 between the ultrasonic probe 4 and the surface 11a of the workpiece 11, the edge of the cut groove 15 on the surface 11a side from the ultrasonic probe 4 is Ultrasonic waves are made to enter 15a.

Thereby, the reflected waves reflected from the edge 15a are detected by the ultrasonic probe 4 without immersing the workpiece 11 in the water tank 34 filled with the liquid 32. Note that in the second embodiment as well, similarly to the first embodiment, ultrasonic waves are irradiated at a plurality of positions across the cutting groove 15 and reflected waves are detected. Further, the operation of detecting reflected waves of ultrasonic waves at a plurality of positions across the cutting groove 15 is repeatedly performed along the longitudinal direction of the cutting groove 15.

Then, similar to the first embodiment, a conversion step (S40) and a measurement step (S50) are performed. In the second embodiment, after the cutting process (S20), the reflected wave detection process (S30 )It can be performed.

Therefore, compared to the case where the workpiece 11 is immersed in the liquid 32 in the water tank 34, it becomes easier to measure the size of the chipping 15b. In addition, the structure, method, etc. according to the above embodiments can be modified and implemented as appropriate without departing from the scope of the objective of the present invention.

2: Ultrasonic imaging device 4: Ultrasonic probe 6: Transmission/reception switching unit 8: Transmission unit 10: Receiving unit 11: Workpiece 11a: Surface 12: Image conversion processing unit 14: Display device 15: Cutting groove 15a: Edge 15b: Chipping 16: Control unit 17: Dicing tape 18: Input device 19: Annular frame 20, 20a: Cutting device 21: Workpiece unit 24: Chuck table 26: Cutting unit 28: Spindle housing 30: Cutting blade 32 , 40: Liquid 34: Water tank 36: Arm 38: Liquid supply nozzle P ₁ : Peak

Claims (3)

A measurement method in which a cutting groove is formed in a workpiece by cutting the workpiece with a rotating cutting blade, and then the size of chipping formed at the edge of the cutting groove due to cutting is measured. ,
a reflected wave detection step of injecting ultrasonic waves into the edge of the cutting groove and detecting the reflected wave reflected from the edge;
a conversion step of converting the reflected wave into image data based on a color tone set in advance according to the reflected wave;
a measuring step of measuring the size of chipping formed at the edge of the cut groove from the image data or from an image created from the image data;
Equipped with
In the reflected wave detection step, an ultrasonic probe and a liquid supply nozzle whose positions are fixed with respect to the cutting unit to which the cutting blade is installed are used, and the ultrasonic probe and the workpiece are connected to each other. While the liquid is being supplied from the liquid supply nozzle, ultrasonic waves are incident on the edge of the cutting groove from the ultrasonic probe, and the ultrasonic wave is reflected from the edge by the ultrasonic probe. A measuring method characterized by detecting the reflected wave . 2. The measuring method according to claim 1, wherein in the conversion step, the reflected wave is converted into the image data based on a color tone set depending on the magnitude of the intensity of the reflected wave. A claim characterized in that the reflected wave detection step includes repeatedly performing the work of detecting reflected waves by injecting ultrasonic waves at a plurality of positions across the cutting groove along the longitudinal direction of the cutting groove. The measuring method according to item 1 or 2.

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