JP2024068982A - Cutting blade detection mechanism - Google Patents

Abstract

[Problem] To provide a cutting blade detection mechanism capable of suppressing a decrease in detection accuracy of the state of a cutting blade. [Solution] The cutting blade detection mechanism 1 has a plurality of light emitters 10, a plurality of light receivers 20, a blade entry section 5 formed between the light emitters 10 and the light receivers 20, a photoelectric converter 30 that converts light 13 received by each of the light receivers 20 into a voltage value corresponding to the amount of light, an amplifier 40 that adjusts the voltage value output from the photoelectric converter 30, and a control unit 170, the control unit 170 including a high voltage value specifying section 172 that specifies the highest voltage value among the voltage values output from the photoelectric converter 30 when the cutting blade 121 is not present in the blade entry section 5, and an amplifier adjustment section 173 that adjusts the amplifier 40 so that the voltage value becomes the highest voltage value specified by the high voltage value specifying section 172. [Selected Figure] Figure 5

Description

The present invention relates to a cutting blade detection mechanism for detecting the state of a cutting blade installed in a cutting device that cuts wafers such as semiconductor wafers.

A cutting device called a dicer is usually used to separate semiconductor wafers into chips. This cutting device is equipped with a cutting blade detection mechanism to detect when the annular cutting edge of the cutting blade needs to be replaced if the cutting blade's diameter has decreased due to wear, and to detect when the annular cutting edge is chipped (see, for example, Patent Documents 1 and 2).

The cutting blade detection mechanism includes a blade entry section where the annular cutting edge of the cutting blade enters, and multiple light emitters and light receivers (both made of optical fibers) arranged opposite the blade entry section. This cutting blade detection mechanism detects the state of the annular cutting edge of the cutting blade located in the blade entry section between the light emitters and the light receiver by receiving the light emitted by the light emitters and converting it into a voltage corresponding to the amount of light received by the light receiver.

JP 2010-141009 A Japanese Patent No. 5236918

The amount of light received by each of the multiple light receivers in the cutting blade detection mechanism described in Patent Documents 1 and 2, etc., differs for each light receiver. This is because the light emitted by the light emitters does not travel in a straight line but is scattered, so that among the light receivers arranged in a row, the amount of light received by the light receivers located on the inside is large, and conversely, the amount of light received by the light receivers located on the outside is small due to the amount of light that escapes.

Variations in the amount of light received by multiple light receivers lead to a decrease in the accuracy of detecting the condition of the cutting blade, so a method to reduce this variation was needed.

The object of the present invention is to provide a cutting blade detection mechanism that can suppress a decrease in the detection accuracy of the cutting blade condition.

In order to solve the above-mentioned problems and achieve the object, the cutting blade detection mechanism of the present invention comprises a plurality of light emitting means arranged adjacent to each other in series in the radial direction of the cutting blade on one side in the rotational axis direction of the cutting blade having an annular cutting edge for cutting a workpiece held on a chuck table that holds the workpiece, a plurality of light receiving means arranged opposite the plurality of light emitting means on the other side in the rotational axis direction of the cutting blade and receiving light irradiated by the light emitting means, a blade penetration portion formed between the plurality of light emitting means and the plurality of light receiving means, and a plurality of light receiving means for converting the light received by each of the plurality of light receiving means into a voltage value corresponding to the amount of light. A cutting blade detection mechanism for a cutting device having a photoelectric converter, an amplifier that adjusts the voltage value output from the photoelectric converter, and a control means, the control means having a high voltage value determination unit that determines the highest voltage value from among the voltage values output from the photoelectric converter when the cutting blade is not in the blade entry section, and an amplifier adjustment unit that adjusts the amplifier so that the respective voltage values are uniform based on the highest voltage value determined by the high voltage value determination unit, and is characterized in that it is possible to detect the cutting blade with high accuracy by reducing the effect of variations due to the amount of light received by each of the multiple light receiving means.

The present invention has the effect of suppressing a decrease in the accuracy of detecting the state of the cutting blade.

FIG. 1 is a perspective view showing an example of the configuration of a cutting device including a cutting blade detection mechanism according to a first embodiment. FIG. 2 is a perspective view of a cutting unit of the cutting apparatus shown in FIG. FIG. 3 is a front view, partially in section, showing the configuration of a cutting blade detection mechanism of the cutting machine shown in FIG. FIG. 4 is a diagram showing the light emitter and light receiver of the cutting blade detection mechanism shown in FIG. FIG. 5 is a block diagram showing the configuration of the cutting blade detection mechanism shown in FIG.

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

[Embodiment 1]
A cutting blade detection mechanism of a cutting device according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing a configuration example of a cutting device equipped with the cutting blade detection mechanism of the cutting device according to the first embodiment. Fig. 2 is a perspective view of a cutting unit of the cutting device shown in Fig. 1. Fig. 3 is a front view, partially in cross section, showing the configuration of the cutting blade detection mechanism of the cutting device shown in Fig. 1. Fig. 4 is a diagram showing a light emitter and a light receiver of the cutting blade detection mechanism shown in Fig. 3. Fig. 5 is a block diagram showing the configuration of the cutting blade detection mechanism shown in Fig. 3.

(Workpiece)
The cutting blade detection mechanism 1 of the cutting device according to the first embodiment constitutes the cutting device 100 shown in Fig. 1. The cutting device 100 shown in Fig. 1 is a processing device that cuts a workpiece 200. In the first embodiment, the workpiece 200 to be processed by the cutting device 100 is a wafer such as a disk-shaped semiconductor wafer or an optical device wafer, the substrate of which is silicon, sapphire, gallium arsenide, SiC (silicon carbide), or the like. The workpiece 200 has devices 203 formed in areas partitioned in a lattice pattern by a plurality of planned division lines 202 formed in a lattice pattern on a surface 201.

The device 203 is, for example, an integrated circuit such as an IC (Integrated Circuit) or an LSI (Large Scale Integration), an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), a MEMS (Micro Electro Mechanical Systems), or a memory (semiconductor memory device).

In the first embodiment, the workpiece 200 has a disk-shaped adhesive tape 205, which is larger in diameter than the workpiece 200, adhered to the back surface 204 behind the front surface 201, and a circular ring-shaped frame 206 is adhered to the outer edge of the adhesive tape 205, so that the workpiece 200 is supported by the ring-shaped frame 206.

In the first embodiment, the workpiece 200 is a wafer such as a semiconductor wafer or an optical device wafer, but in the present invention, the workpiece is not limited to a wafer and may be various other workpieces such as package substrates such as ceramic capacitor substrates and CSP (chip size package) substrates.

(Cutting device)
1 is a processing device that holds a workpiece 200 on a chuck table 110 and cuts it with a cutting blade 121 along a planned division line 202. As shown in FIG. 1, the cutting device 100 includes a chuck table 110 that suction-holds the workpiece 200 on a holding surface 111, a cutting unit 120 that cuts the workpiece 200 held by the chuck table 110 with the cutting blade 121, an imaging unit 130 that images the workpiece 200 held by the chuck table 110, and a control unit 170 that is a control means.

The cutting device 100 also includes a moving unit 140 that moves the chuck table 110 relative to the cutting unit 120. The moving unit 140 includes an X-axis moving unit 141 that moves the chuck table 110 in the X-axis direction parallel to the horizontal direction, a Y-axis moving unit 142 that moves the cutting unit 120 in the Y-axis direction parallel to the horizontal direction and perpendicular to the X-axis direction, a Z-axis moving unit 143 that moves the cutting unit 120 in the Z-axis direction parallel to the vertical direction perpendicular to both the X-axis and Y-axis directions, and a rotational moving unit 144 that rotates the chuck table 110 around an axis parallel to the Z-axis direction.

The X-axis moving unit 141 is installed on the device body 101 of the cutting device 100. The X-axis moving unit 141 moves the chuck table 110 in the X-axis direction, which is the processing feed direction, to feed the chuck table 110 and the cutting unit 120 relatively along the X-axis direction. The Y-axis moving unit 142 and the Z-axis moving unit 143 are installed on the support frame 102 standing upright from the device body 101. The Y-axis moving unit 142 moves the cutting unit 120 in the Y-axis direction, which is the indexing feed direction, to feed the chuck table 110 and the cutting unit 120 relatively along the Y-axis direction. The Z-axis moving unit 143 moves the cutting unit 120 in the Z-axis direction, which is the cutting feed direction, to feed the chuck table 110 and the cutting unit 120 relatively along the Z-axis direction. The rotation moving unit 144 is moved in the X-axis direction together with the chuck table 110 by the X-axis moving unit 141.

The X-axis moving unit 141, the Y-axis moving unit 142, and the Z-axis moving unit 143 each include a well-known ball screw that is rotatable about its axis, a well-known motor that rotates the ball screw about its axis to move the chuck table 110 or the cutting unit 120 in the X-axis, Y-axis, or Z-axis direction, and a well-known guide rail that supports the chuck table 110 or the cutting unit 120 so that it can move in the X-axis, Y-axis, or Z-axis direction. The rotational movement unit 144 includes a well-known motor that rotates the chuck table 110 about its axis.

The chuck table 110 is disk-shaped, and the holding surface 111 that holds the workpiece 200 is formed from porous ceramics or the like. The chuck table 110 is provided so as to be movable in the X-axis direction by the X-axis movement unit 141 between the processing area below the cutting unit 120 and the load/unload area that is spaced from below the cutting unit 120 and where the workpiece 200 is loaded and unloaded, and is provided so as to be rotatable about an axis parallel to the Z-axis direction by the rotation movement unit 144.

The holding surface 111 of the chuck table 110 is connected to a vacuum suction source (not shown), and the workpiece 200 placed on the holding surface 111 is suction-held by the vacuum suction source. In the first embodiment, the chuck table 110 suction-holds the back surface 204 of the workpiece 200 via an adhesive tape 205. In addition, a plurality of clamping portions 112 that clamp the annular frame 206 are provided around the periphery of the chuck table 110, as shown in FIG. 1.

The cutting unit 120 is a processing unit that can attach an annular cutting blade 121 to the tip of a spindle 123. The cutting unit 120 is provided so as to be movable in the Y-axis direction by a Y-axis moving unit 142 and movable in the Z-axis direction by a Z-axis moving unit 143 relative to the workpiece 200 held on the chuck table 110. The cutting unit 120 can position the cutting blade 121 at any position on the holding surface 111 of the chuck table 110 by the X-axis moving unit 141, the Y-axis moving unit 142, and the Z-axis moving unit 143.

As shown in FIG. 1, the cutting unit 120 has a cutting blade 121, a spindle housing 122 that is movable in the Y-axis direction and the Z-axis direction by a Y-axis moving unit 142 and a Z-axis moving unit 143, a spindle 123 that is rotatable about its axis on the spindle housing 122, and a spindle motor (not shown) that rotates the spindle 123 about its axis.

The cutting blade 121 is an extremely thin cutting grindstone having a substantially ring shape. In the first embodiment, as shown in FIG. 2 and FIG. 3, the cutting blade 121 has an annular cutting edge 124 that cuts the workpiece 200 held on the chuck table 110, and an annular base 125 that supports the cutting edge 124 at its outer edge and is detachably attached to the spindle 123. The cutting edge 124 is made of abrasive grains such as diamond or CBN (Cubic Boron Nitride) and a bond material such as metal or resin, and is formed to a predetermined thickness. In the present invention, the cutting blade 121 may be a so-called washer blade consisting of only the cutting edge 124. During cutting of the workpiece 200, a part of the cutting edge 124 of the cutting blade 121 may be chipped.

The spindle housing 122 is supported by the Z-axis moving unit 143 so as to be freely movable in the Z-axis direction, and is supported by the Y-axis moving unit 142 via the Z-axis moving unit 143 so as to be freely movable in the Y-axis direction. The spindle housing 122 houses the spindle 123 except for the tip portion, as well as a spindle motor (not shown), and supports the spindle 123 so as to be rotatable around its axis.

The cutting blade 121 is attached to the tip of the spindle 123. The spindle 123 is rotated around its axis by a spindle motor (not shown), and its tip protrudes from the tip surface of the spindle housing 122. The tip of the spindle 123 is gradually tapered toward the tip, and the cutting blade 121 is attached to it. The axes of the spindle 123 and cutting blade 121 of the cutting unit 120 are parallel to the Y-axis direction. In other words, the cutting blade 121 of the cutting unit 120 is rotated around its axis by the spindle motor.

As shown in FIG. 2, the cutting unit 120 also has a blade cover 126 attached to the tip surface of the spindle 123 and a cutting water nozzle 127 that supplies cutting water to the cutting blade 121.

The blade cover 126 covers at least the upper part of the cutting blade 121. The blade cover 126 is fixed to the tip surface of the spindle housing 122.

The cutting water nozzle 127 supplies cutting water to the cutting blade 121 when the cutting blade 121 cuts the workpiece 200 held by the holding surface 111 of the chuck table 110. As shown in FIG. 2, the cutting water nozzle 127 includes a shower nozzle 128 and a pair of blade nozzles 129.

The nozzles 128 and 129 are attached to the blade cover 126, and cutting water is supplied from a cutting water supply source (not shown). The shower nozzle 128 has a nozzle that faces the tip of the cutting edge 124 of the cutting blade 121 in the X-axis direction, and supplies cutting water from the nozzle to the tip of the cutting edge 124 of the cutting blade 121 during cutting.

The blade nozzles 129 extend parallel to the X-axis direction and are spaced apart from one another in the Y-axis direction. The blade nozzles 129 position the lower end of the cutting edge 124 of the cutting blade 121 between each other and are equipped with a jet nozzle (not shown) that faces the lower end of the cutting edge 124 of the cutting blade 121. The blade nozzle 129 supplies cutting water from the jet nozzle to the lower end of the cutting edge 124 of the cutting blade 121 during cutting.

The imaging unit 130 is fixed to the cutting unit 120 so as to move integrally with the cutting unit 120. The imaging unit 130 includes an imaging element that captures an image of the area to be divided of the workpiece 200 held on the chuck table 110 before cutting. The imaging element is, for example, a CCD (Charge-Coupled Device) imaging element or a CMOS (Complementary MOS) imaging element having multiple pixels. The imaging unit 130 captures an image of the surface 201 of the workpiece 200 held on the chuck table 110 with the imaging element through an objective lens.

The imaging unit 130 photographs the workpiece 200 held on the chuck table 110, acquires images to perform alignment between the workpiece 200 and the cutting blade 121, and outputs the acquired images to the control unit 170.

The cutting device 100 also includes an X-axis position detection unit (not shown) for detecting the position of the chuck table 110 in the X-axis direction, a Y-axis position detection unit (not shown) for detecting the position of the cutting unit 120 in the Y-axis direction, a Z-axis position detection unit for detecting the position of the cutting unit 120 in the Z-axis direction, and an angle detection unit for detecting the angle around the axis of the chuck table 110. The X-axis position detection unit and the Y-axis position detection unit can be configured with a linear scale parallel to the X-axis direction or the Y-axis direction, and a reading head. The Z-axis position detection unit detects the position of the cutting unit 120 in the Z-axis direction with motor pulses. The angle detection unit is configured with a well-known rotary encoder or the like.

The X-axis position detection unit, the Y-axis position detection unit, and the Z-axis position detection unit output the position of the chuck table 110 in the X-axis direction and the cutting unit 120 in the Y-axis direction or the Z-axis direction to the control unit 170. The angle detection unit outputs the angle from a reference position around the axis of the chuck table 110 to the control unit 170. In the first embodiment, the positions of each component of the cutting device 100 in the X-axis direction, Y-axis direction, and Z-axis direction are determined based on a predetermined reference position (not shown).

The cutting device 100 also includes a cassette elevator 150 on which a cassette 151 that contains the workpiece 200 before and after cutting is placed and which moves the cassette 151 in the Z-axis direction, a cleaning unit 160, and a transport unit (not shown). The cassette 151 is a container that can contain multiple workpieces 200 spaced apart in the Z-axis direction, and is provided with an access port 152 that allows the workpieces 200 to be inserted and removed. The cassette elevator 150 is disposed next to one side in the Y-axis direction of the chuck table 110 positioned in the loading/unloading area, and the cassette 151 is placed with the access port 152 positioned on the side of the chuck table 110 positioned in the loading/unloading area.

The cleaning unit 160 cleans the workpiece 200 after cutting. The cleaning unit is located next to the other side in the Y-axis direction of the chuck table 110 positioned in the load/unload area, and is located in a position aligned in the Y-axis direction with the cassette 151 and the chuck table 110 positioned in the load/unload area. The cleaning unit 160 includes a spinner table 161 that holds the workpiece by suction, and a cleaning liquid supply nozzle 162 that supplies cleaning liquid to the surface 201 of the workpiece 200 held by suction on the spinner table 161.

The transport unit transports the workpiece 200 between the cassette 151, the chuck table 110, and the spinner table 161 of the cleaning unit 160.

The control unit 170 also controls each of the components of the cutting device 100, causing the cutting device 100 to perform a machining operation on the workpiece 200. The control unit 170 is a computer having an arithmetic processing device having a microprocessor such as a CPU (central processing unit), a storage device having a memory such as a ROM (read only memory) or a RAM (random access memory), and an input/output interface device. The arithmetic processing device of the control unit 170 performs arithmetic processing according to a computer program stored in the storage device, and outputs control signals for controlling the cutting device 100 to each of the components of the cutting device 100 via the input/output interface device.

The control unit 170 is connected to a display unit (not shown) configured with a liquid crystal display device or the like that displays the status and images of the machining operation, an input unit used by the operator to register machining conditions, and an alarm unit. The input unit is configured with at least one of a touch panel provided on the display unit and an external input device such as a keyboard. The alarm unit emits at least one of sound and light to alert the operator.

The control unit 170 also includes a machining control section 171. The machining control section 171 controls each of the above-mentioned components of the cutting device 100, and causes each component of the cutting device 100 to perform a machining operation on the workpiece 200. The function of the machining control section 171 is realized by the arithmetic processing device performing arithmetic processing in accordance with a computer program stored in the storage device.

The cutting device 100 also includes a cutting blade detection mechanism 1, a portion of which is shown in FIG. 3. The cutting blade detection mechanism 1 detects the state of the cutting edge 124 of the cutting blade 121. In the present invention, the cutting blade detection mechanism 1 detects the state of the cutting edge 124 of the cutting blade 121, including whether or not the cutting edge 124 is chipped, the position of the tip of the cutting edge 124, which indicates the wear state of the cutting edge 124, and whether or not the cutting edge 124 is chipped along the entire circumference.

(Cutting blade detection mechanism)
As shown in Fig. 3, the cutting blade detection mechanism 1 includes a mechanism body 2, a plurality of light emitters 10, and a plurality of light receivers 20. The mechanism body 2 is attached to a blade cover 126 and disposed above the cutting blade 121. The mechanism body 2 includes a pair of vertical parts 3 spaced apart from each other along the Y-axis direction and extending in the Z-axis direction, which position the cutting edge 124 of the cutting blade 121 between them, and a connecting part 4 connecting the upper ends of the vertical parts 3. The mechanism body 2 forms a blade insertion part 5 that allows the cutting edge 124 of the cutting blade 121 to enter between the pair of vertical parts 3. That is, the cutting blade detection mechanism 1 includes the blade insertion part 5.

The mechanism body 2 has an adjustment screw 6 attached to the connecting part 4, which is screwed into a screw hole in the blade cover 126. When the adjustment screw 6 is rotated around its axis by an operator or the like, the mechanism body 2 is moved relative to the blade cover 126 along the Z-axis direction, and the radial position of the cutting edge 124 of the cutting blade 121 relative to the blade cover 126 is adjusted.

The light emitters 10 are arranged on one side of the vertical portion 3 (hereinafter, indicated by reference numeral 3-1) in the Y-axis direction, which is the axis of rotation of the cutting blade 121. As shown in Figs. 3 and 4, the light emitters 10 are arranged adjacent to each other in series in the radial direction of the cutting edge 124 of the cutting blade 121. The light emitters 10 face the vertical portion 3 (hereinafter, indicated by reference numeral 3-2) on the other side, and are arranged on a straight line along the Z-axis direction, i.e., the radial direction of the cutting edge 124 of the cutting blade 121. The light emitters 10 are the ends of the optical fibers 12 connected to the light emitting elements 11 shown in Fig. 5, and irradiate the light 13 emitted by the light emitting elements 11 toward the vertical portion 3-2 on the other side. The light emitting elements 11 are, for example, LEDs (Light-Emitting Diodes) or LDs (Laser Diodes).

The multiple photoreceptors 20 are arranged on the vertical portion 3-2 on the other side in the Y-axis direction, which is the rotation axis of the cutting blade 121. As shown in Figures 3 and 4, the multiple photoreceptors 20 are arranged on the vertical portion 3-2 on the other side adjacent to each other in series in the radial direction of the cutting edge 124 of the cutting blade 121. The multiple photoreceptors 20 are arranged on the vertical portion 3-2 on the other side facing the vertical portion 3-1 on one side, and are arranged in a straight line along the Z-axis direction, i.e., the radial direction of the cutting edge 124 of the cutting blade 121, facing the multiple light emitters 10.

The light receivers 20 correspond one-to-one to the light emitters 10 and face the corresponding light emitters 10 along the Y-axis direction, which is the rotation axis of the cutting blade 121. The light receivers 20 are the ends of the optical fibers 22, and each receives at least the light 13 emitted by the corresponding light emitter 10. In the embodiment, the light receivers 20 also receive light 13 from light emitters 10 other than the corresponding light emitter 10. In the first embodiment, the amount of light 13 received by the end light receivers 20 among the multiple arranged light receivers 20 is less than the amount of light 13 received by the center light receiver 20.

In the first embodiment, 16 light emitters 10 and 16 light receivers 20 are disposed on each of the vertical sections 3-1 and 3-2. In the first embodiment, the light emitters 10 and the light receivers 20 are disposed on the vertical sections 3-1 and 3-2, respectively, so that the blade entry section 5 is formed between the multiple light emitters 10 and the multiple light receivers 20.

As shown in FIG. 5, the cutting blade detection mechanism 1 includes a photoelectric converter 30, an amplifier 40, and a control unit 170, which is a control means. In this manner, in the first embodiment, the control unit 170 controls the machining operations of the entire cutting device 100 and also constitutes the cutting blade detection mechanism 1. However, in the present invention, the control means constituting the cutting blade detection mechanism 1 may be provided separately from the control unit 170, which controls the machining operations of the entire cutting device 100.

The photoelectric converter 30 converts the light 13 received by each of the multiple photoreceptors 20 into a signal 31 with a voltage value corresponding to the amount of light 13. In the first embodiment, a plurality of photoelectric converters 30 are provided in one-to-one correspondence with the photoreceptors 20. The photoelectric converter 30 is connected to the other end of the optical fiber 22, the end of which is the photoreceptor 20, and is connected to the corresponding photoreceptor 20. That is, in the first embodiment, the same number of photoelectric converters 30 as the light emitters 10 are provided. The photoelectric converter 30 converts the light 13 received by the corresponding photoreceptor 20, which is transmitted by the optical fiber 22, into a signal 31 with a voltage value corresponding to the amount of light, and outputs the converted signal 31 to the amplifier 40.

The amplifier 40 adjusts the voltage value of the signal 31 output from the photoelectric converter 30. A plurality of amplifiers 40 are provided in one-to-one correspondence with the photoreceptors 20 and photoelectric converters 30. That is, in the first embodiment, the same number of amplifiers 40 as the light emitters 10, photoreceptors 20, and photoelectric converters 30 are provided. The amplifiers 40 adjust the voltage value of the signal 31 output from the corresponding photoelectric converter 30, and output the adjusted signal 41 to the transmittance calculation unit 174 of the control unit 170.

In addition, in the first embodiment, the functions of the photoelectric converter 30 and the amplifier 40 are realized by a dedicated processing circuit (hardware), such as a single circuit, a composite circuit, a programmed processor, or a parallel programmed processor.

In addition, in embodiment 1, the control unit 170 constituting the cutting blade detection mechanism 1 includes a high voltage value identification unit 172, an amplifier adjustment unit 173, and a transmittance calculation unit 174, as shown in FIG. 5.

The high voltage value identification unit 172 identifies the highest voltage value among the voltage values of the signals 31 output from the photoelectric converter 30 when the cutting edge 124 of the cutting blade 121 is not present within the blade entry portion 5. The high voltage value identification unit 172 identifies the highest voltage value among the voltage values of the signals 31 output from the photoelectric converter 30 when the cutting edge 124 of the cutting blade 121 is located outside the blade entry portion 5.

The amplifier adjustment unit 173 adjusts the amplifier 40 so that the voltage values of the signals 41 are uniform based on the highest voltage value identified by the high voltage value identification unit 172. The amplifier adjustment unit controls the amplifier 40 so that the voltage value of the signal 41 after the voltage value adjustment becomes the highest voltage value identified by the high voltage value identification unit 172, that is, the amplifier 40 adjusts the voltage value of each signal 41 to the highest voltage value identified by the high voltage value identification unit 172.

The transmittance calculation unit 174 sums up the voltage values of the signals 41 output from all the amplifiers 40, calculates the transmittance of the light 13 received by the light receivers 20 based on the summed voltage value, and detects the state of the cutting edge 124 of the cutting blade 121. The transmittance is a value that is set to 100 percent when all the light receivers 20 receive the light 13, and 0 percent when none of the light receivers 20 receive the light 13, that is, a value that indicates the proportion of the light 13 irradiated by the multiple light emitters 10 that is transmitted through the blade entry portion 5. In short, the transmittance is a value that increases as the cutting edge 124 of the cutting blade 121 that has entered the blade entry portion 5 wears, and periodically increases when part of the cutting edge 124 of the cutting blade 121 that has entered the blade entry portion 5 is chipped.

The functions of the high voltage value determination unit 172, the amplifier adjustment unit 173, and the transmittance calculation unit 174 are realized by the calculation processing unit performing calculation processing in accordance with a computer program stored in the storage device.

When the cutting device 100 having the above-mentioned configuration is shipped from the factory, or during regular maintenance, the voltage value of the signal 41 output by each amplifier 40 of the cutting blade detection mechanism 1 is adjusted as shown below. When adjusting the voltage value, the cutting device 100 irradiates light 13 from the multiple light emitters 10 toward the multiple light receivers 20 without the cutting blade 121 being attached to the spindle 123. In the cutting device 100, each photoelectric converter 30 converts the light 13 from the light emitters 10 received by each light receiver 20 into a signal 31, and outputs the converted signal 31 to the amplifier 40.

In the first embodiment, the photoelectric converter 30 converts the light 13 received by the photoreceptors 20 (hereinafter, denoted by reference numeral 20-1) located at both ends of the multiple photoreceptors 20, for example, into a signal 31 having a voltage value of 10 mV, and outputs the signal to the amplifier 40. In the first embodiment, the photoelectric converter 30 converts the light 13 received by the photoreceptor 20 (hereinafter, denoted by reference numeral 20-2) adjacent to the photoreceptor 20-1, for example, into a signal 31 having a voltage value of 12 mV, and outputs the signal to the amplifier 40. In the first embodiment, the photoelectric converter 30 converts the light 13 received by the remaining photoreceptors 20, for example, into a signal 31 having a voltage value of 13 mV, and outputs the signal to the amplifier 40.

Then, in the cutting device 100, the high voltage value identification unit 172 identifies the highest voltage value among the voltage values of the signal 31 converted by the photoelectric converter 30. In the first embodiment, the high voltage value identification unit 172 identifies the highest voltage value as 13 mV.

In the cutting device 100, the amplifier adjustment unit 173 adjusts the voltage values of all signals 41 output by the amplifier 40 to the highest voltage value identified by the high voltage value identification unit 172. In the first embodiment, the amplifier adjustment unit 173 adjusts the voltage values of all signals 41 output by the amplifier 40 to 13 mV. In this way, the cutting device 100 adjusts the voltage values of the signals 41 output by the amplifier 40 of the cutting blade detection mechanism 1.

In addition, in the cutting device 100, the processing control unit 171 controls each of the above-mentioned components of the cutting device 100, and during the processing operation in which the workpiece 200 held on the chuck table 110 is cut with the cutting blade 121 while supplying cutting water, the multiple light emitters 10 of the cutting blade detection mechanism 1 irradiate light 13 toward the multiple light receivers 20, and the transmittance calculation unit 174 detects the state of the cutting edge 124 of the cutting blade 121. For example, in the cutting device 100, when the cutting blade detection mechanism 1 detects that a part or the entire cutting edge 124 of the cutting blade 121 is chipped, the processing control unit 171 of the control unit 170 stops the processing operation and operates the notification unit to notify the operator.

As described above, in the cutting blade detection mechanism 1 according to the first embodiment, the high voltage value identification unit 172 identifies the highest voltage value among the voltage values of the signal 31 converted by the photoelectric converter 30, and the amplifier adjustment unit 173 adjusts the voltage values of all the signals 41 output by the amplifier 40 to the highest voltage value identified by the high voltage value identification unit 172. In this way, in the cutting blade detection mechanism 1 according to the first embodiment, the amplifier adjustment unit 173 adjusts the amplifier 40 so that the voltage values of the signals 41 are uniform based on the highest voltage value identified by the high voltage value identification unit 172, and the voltage values of the signals 41 input to the transmittance calculation unit 174 are uniformed, so that the total value of the voltage values of all the signals 41 input to the transmittance calculation unit 174 can be brought close to a value corresponding to the position of the tip of the cutting edge 124 of the cutting blade 121 in the blade insertion portion 42.

As a result, the cutting blade detection mechanism 1 according to the first embodiment reduces the effect of variations in the amount of light 13 received by each of the multiple light receivers 20, enabling detection of the cutting blade 121 with high accuracy, i.e., suppressing a decrease in the detection accuracy of the state of the cutting edge 124 of the cutting blade 121.

The present invention is not limited to the above-described embodiment. In other words, the present invention can be modified in various ways without departing from the gist of the invention.

1 Cutting blade detection mechanism 5 Blade entry part 10 Light emitter (light emitting means)
13 Light 20 Light receiver (light receiving means)
30 Photoelectric converter 40 Amplifier 100 Cutting device 110 Chuck table 121 Cutting blade 124 Cutting edge 170 Control unit (control means)
172 High voltage value specifying unit 173 Amplifier adjustment unit 200 Workpiece

Claims (1)

A cutting blade detection mechanism for a cutting machine, comprising: a plurality of light emitting means arranged adjacent to each other in series in a radial direction of a cutting blade on one side in a rotation axis direction of the cutting blade, the cutting blade having an annular cutting edge for cutting a workpiece held on a chuck table that holds the workpiece; a plurality of light receiving means arranged opposite to the plurality of light emitting means on the other side in the rotation axis direction of the cutting blade and receiving light irradiated by the light emitting means; a blade entry portion formed between the plurality of light emitting means and the plurality of light receiving means; and a photoelectric converter that converts light respectively received by the plurality of light receiving means into a voltage value corresponding to an amount of light,
an amplifier that adjusts the voltage value output from the photoelectric converter;
A control means,
The control means
a high voltage value identifying unit that identifies the highest voltage value from among the voltage values output from the photoelectric converter when the cutting blade is not present within the blade entry portion;
an amplifier adjustment unit that adjusts the amplifier so that the respective voltage values are uniform based on the highest voltage value specified by the high voltage value specifying unit;
A cutting blade detection mechanism that is equipped with the above-mentioned and that reduces the influence of variations in the amount of light received by each of the multiple light receiving means and is capable of detecting the cutting blade with high accuracy.

Images