Cutting blade detection mechanism

Abstract

To provide a cutting blade detecting mechanism that can suppress accuracy in detecting a condition of a cutting blade from deteriorating.SOLUTION: A cutting blade detecting mechanism 1 comprises: a plurality of light emitting bodies 10; a plurality of light receiving bodies 20; blade intruding parts 5 formed between the light emitting bodies 10 and the light receiving bodies 20; photoelectricity converters 30 that convert light 13 received by the light receiving bodies 20 respectively to voltage values corresponding to light quantities; amplifiers 40 that adjust the voltage values outputted from the photoelectricity converters 30; and a control unit 170. The control unit 170 comprises: a high voltage value identifying part 172 that identifies a highest voltage value out of voltage values outputted from the photoelectricity converters 30 in a state where there are no cutting blades 121 left in the blade intruding parts 5; and an amplifier adjusting part 173 that adjusts the amplifiers 40 so that the voltage values become equal to the highest voltage value identified by the high voltage value identifying part 172.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a cutting blade detection mechanism for detecting the state of a cutting blade equipped in a cutting device for cutting wafers such as semiconductor wafers.

Background Art

[0002] To individually cut a semiconductor wafer into chips, a cutting device called a dicing saw is usually used. This cutting device includes a cutting blade detection mechanism for detecting the replacement timing of the annular cutting edge of a cutting blade whose diameter has decreased due to wear and the chipping of the annular cutting edge (see, for example, Patent Document 1 and Patent Document 2).

[0003] The above cutting blade detection mechanism includes a blade intrusion portion into which the annular cutting edge of the cutting blade penetrates, and a plurality of light emitters and light receivers (both optical fibers) arranged opposite to the blade intrusion portion. This cutting blade detection mechanism detects the state of the annular cutting edge of the cutting blade located in the blade intrusion portion between the light emitter and the light receiver by the light receiver receiving the light emitted by the light emitter and converting it into a voltage corresponding to the amount of light received by the light receiver.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the cutting blade detection mechanism described in Patent Documents 1 and 2, the amount of light received by each of the multiple photodetectors differs from that of the photodetector. This is because the light emitted by the light-emitting element does not travel in a straight line but is scattered. As a result, among the photodetectors arranged in a line, the amount of light received by the photodetectors located on the inside is greater, while the amount of light received by the photodetectors located on the outside is less due to the light that escapes.

[0006] When the amount of light received by multiple photodetectors varies, it leads to a decrease in the accuracy of detecting the state of the cutting blade, so a method to suppress this variation was needed.

[0007] The objective of the present invention is to provide a cutting blade detection mechanism that can suppress a decrease in the accuracy of detecting the state of the cutting blade. [Means for solving the problem]

[0008] To solve the above-mentioned problems and achieve the objective, 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 rotation axis direction of the cutting blade, which has an annular cutting edge for cutting a workpiece held on a chuck table that holds the workpiece; a plurality of light-receiving means disposed on the other side in the rotation axis direction of the cutting blade, facing the plurality of light-emitting means, 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 mechanism that converts 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 comprising a photoelectric converter, an amplifier for adjusting the voltage output from the photoelectric converter, and a control means, wherein the control means comprises a high-voltage value identification unit for identifying the highest voltage value among the voltage values ​​output from the photoelectric converter when the cutting blade is not in the blade entry portion, and an amplifier adjustment unit for adjusting the amplifier so that the voltage values ​​become uniform based on the highest voltage value identified by the high-voltage value identification unit, thereby reducing the influence of variations due to the amount of light received by each of the plurality of light receiving means and enabling high-precision detection of the cutting blade. [Effects of the Invention]

[0009] This invention has the effect of suppressing a decrease in the accuracy of detecting the state of the cutting blade. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view showing an example of the configuration of a cutting device equipped with a cutting blade detection mechanism according to Embodiment 1. [Figure 2] Figure 2 is a perspective view of the cutting unit of the cutting apparatus shown in Figure 1. [Figure 3] Figure 3 is a partial cross-sectional front view showing the configuration of the cutting blade detection mechanism of the cutting device shown in Figure 1. [Figure 4] Figure 4 shows the light-emitting element and light-receiving element of the cutting blade detection mechanism shown in Figure 3. [Figure 5] Figure 5 is a block diagram showing the configuration of the cutting blade detection mechanism shown in Figure 3. [Modes for carrying out the invention]

[0011] Embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by those skilled in the art, and those that are substantially the same. In addition, the components described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the present invention.

[0012] [Embodiment 1] A cutting blade detection mechanism for a cutting device according to Embodiment 1 of the present invention will be described based on the drawings. Figure 1 is a perspective view showing an example of the configuration of a cutting device equipped with the cutting blade detection mechanism according to Embodiment 1. Figure 2 is a perspective view of the cutting unit of the cutting device shown in Figure 1. Figure 3 is a front view showing a partial cross-section of the configuration of the cutting blade detection mechanism of the cutting device shown in Figure 1. Figure 4 is a diagram showing the light emitter and light receiver of the cutting blade detection mechanism shown in Figure 3. Figure 5 is a block diagram showing the configuration of the cutting blade detection mechanism shown in Figure 3.

[0013] (Workpiece) The cutting blade detection mechanism 1 of the cutting apparatus according to Embodiment 1 constitutes the cutting apparatus 100 shown in Figure 1. The cutting apparatus 100 shown in Figure 1 is a processing apparatus that cuts a workpiece 200. In Embodiment 1, the workpiece 200 to be processed by the cutting apparatus 100 is a wafer such as a disc-shaped semiconductor wafer or optical device wafer with a substrate of silicon, sapphire, gallium arsenide, or SiC (silicon carbide), etc. The workpiece 200 has a device 203 formed in a grid-like region partitioned by a plurality of division lines 202 formed in a grid pattern on the surface 201.

[0014] Device 203 is, for example, an integrated circuit such as an IC (Integrated Circuit) or LSI (Large Scale Integration), an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), a MEMS (Micro Electro Mechanical Systems), or a memory (semiconductor memory device).

[0015] In Embodiment 1, a disc-shaped adhesive tape 205 with a larger diameter than the workpiece 200 is attached to the back surface 204 of the back side of the front surface 201 of the workpiece 200, and an annular frame 206 is attached to the outer edge of the adhesive tape 205, and the workpiece is supported by the annular frame 206.

[0016] In the first embodiment, the workpiece 200 is a wafer such as a semiconductor wafer or an optical device wafer. However, in the present invention, the workpiece is not limited to a wafer, and various workpieces such as a package substrate such as a ceramic capacitor substrate or a CSP (chip size package) substrate may be used.

[0017] (Cutting device) The cutting device 100 shown in FIG. 1 is a processing device that holds the workpiece 200 by the chuck table 110 and cuts it with the cutting blade 121 along the planned division line 202. As shown in FIG. 1, the cutting device 100 includes a chuck table 110 that sucks and holds the workpiece 200 on the holding surface 111, a cutting unit 120 that cuts the workpiece 200 held by the chuck table 110 with the cutting blade 12; an imaging unit 130 that images the workpiece 200 held on the chuck table 110; and a control unit 170 that is a control means.

[0018] The cutting device 100 further includes a moving unit 140 that relatively moves the chuck table 110 with respect to the cutting unit 120. The moving unit 140 includes an X-axis moving unit 141 that feeds the chuck table 110 in the X-axis direction parallel to the horizontal direction, a Y-axis moving unit 142 that performs indexing feed on the cutting unit 120 in the Y-axis direction parallel to the horizontal direction and orthogonal to the X-axis direction, a Z-axis moving unit 143 that performs cutting feed on the cutting unit 120 in the Z-axis direction parallel to the vertical direction orthogonal to both the X-axis direction and the Y-axis direction, and a rotational moving unit 144 that rotates the chuck table 110 around an axis parallel to the Z-axis direction.

[0019] The X-axis movement unit 141 is installed on the apparatus main body 101 of the cutting apparatus 100. The X-axis movement unit 141 moves the chuck table 110 in the X-axis direction, which is the machining feed direction, so as to relatively perform machining feed along the X-axis direction between the chuck table 110 and the cutting unit 120. The Y-axis movement unit 142 and the Z-axis movement unit 143 are installed on the support frame 102 erected from the apparatus main body 101. The Y-axis movement unit 142 moves the cutting unit 120 in the Y-axis direction, which is the indexing feed direction, so as to relatively perform indexing feed along the Y-axis direction between the chuck table 110 and the cutting unit 120. The Z-axis movement unit 143 moves the cutting unit 120 in the Z-axis direction, which is the cutting feed direction, so as to relatively perform cutting feed along the Z-axis direction between the chuck table 110 and the cutting unit 120. The rotational movement unit 144 is moved in the X-axis direction together with the chuck table 110 by the X-axis movement unit 141.

[0020] The X-axis movement unit 141, the Y-axis movement unit 142, and the Z-axis movement unit 143 include a well-known ball screw provided rotatably around an axis, a well-known motor that rotates the ball screw around the axis to move the chuck table 110 or the cutting unit 120 in the X-axis direction, the Y-axis direction, or the Z-axis direction, and a well-known guide rail that movably supports the chuck table 110 or the cutting unit 120 in the X-axis direction, the Y-axis direction, or the Z-axis direction. The rotational movement unit 144 includes a well-known motor or the like that rotates the chuck table 110 around an axis.

[0021] The chuck table 110 has a disk shape, and the holding surface 111 for holding the workpiece 200 is formed of porous ceramic or the like. Further, the chuck table 110 is provided movably in the X-axis direction across the machining area below the cutting unit 120 and the loading / unloading area where the workpiece 200 is loaded and unloaded while being separated from below the cutting unit 120 by the X-axis movement unit 141, and is provided rotatably around an axis parallel to the Z-axis direction by the rotational movement unit 144.

[0022] The chuck table 110 has a holding surface 111 connected to a vacuum suction source (not shown), and the workpiece 200 placed on the holding surface 111 is held in place by suction from the vacuum suction source. In Embodiment 1, the chuck table 110 holds the workpiece 200 by suction from the back surface 204 via adhesive tape 205. In addition, as shown in Figure 1, multiple clamping parts 112 for clamping the annular frame 206 are provided around the chuck table 110.

[0023] The cutting unit 120 is a machining unit to which an annular cutting blade 121 can be attached to the tip of a spindle 123. The cutting unit 120 is provided to move freely in the Y-axis direction by a Y-axis movement unit 142 and also moves freely in the Z-axis direction by a Z-axis movement unit 143 relative to the workpiece 200 held in the chuck table 110. The cutting unit 120 allows the cutting blade 121 to be positioned at any position on the holding surface 111 of the chuck table 110 by the X-axis movement unit 141, the Y-axis movement unit 142 and the Z-axis movement unit 143.

[0024] As shown in Figure 1, the cutting unit 120 includes 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 movement unit 142 and a Z-axis movement unit 143, a spindle 123 that is rotatably mounted in the spindle housing 122 around its axis, and a spindle motor (not shown) that rotates the spindle 123 around its axis.

[0025] The cutting blade 121 is an extremely thin cutting wheel having a substantially ring shape. In Embodiment 1, as shown in Figures 2 and 3, the cutting blade 121 comprises an annular cutting edge 124 for cutting the workpiece 200 held on the chuck table 110, and an annular base 125 that supports the cutting edge 124 on its outer edge and is detachably mounted on the spindle 123. The cutting edge 124 is made of abrasive grains such as diamond or CBN (Cubic Boron Nitride) and a bonding material (binder) such as metal or resin, and is formed to a predetermined thickness. In this invention, the cutting blade 121 may also be a so-called washer blade consisting only of the cutting edge 124. During cutting of the workpiece 200, a part of the cutting edge 124 may chip off.

[0026] The spindle housing 122 is supported so as to be movable in the Z-axis direction by the Z-axis movement unit 143, and is also supported so as to be movable in the Y-axis direction by the Y-axis movement unit 142 via the Z-axis movement unit 143. The spindle housing 122 houses the portion of the spindle 123 excluding the tip and a spindle motor (not shown), and supports the spindle 123 so as to be rotatable around its axis.

[0027] The spindle 123 has a cutting blade 121 mounted at its tip. 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 towards the tip, and the cutting blade 121 is mounted thereon. The axes of the spindle 123 and the cutting blade 121 of the cutting unit 120 are parallel to the Y-axis direction. That is, the cutting blade 121 of the cutting unit 120 is rotated around its axis by the spindle motor.

[0028] Furthermore, as shown in Figure 2, the cutting unit 120 includes a blade cover 126 mounted on the tip surface of the spindle 123 and a cutting fluid nozzle 127 that supplies cutting fluid to the cutting blade 121.

[0029] The blade cover 126 covers at least the upper part of the cutting blade 121. The blade cover 126 is fixed to the front end of the spindle housing 122.

[0030] The cutting fluid nozzle 127 supplies cutting fluid to the cutting blade 121 when the cutting blade 121 cuts the workpiece 200 held on the holding surface 111 of the chuck table 110. As shown in Figure 2, the cutting fluid nozzle 127 comprises a shower nozzle 128 and a pair of blade nozzles 129.

[0031] Nozzles 128 and 129 are attached to the blade cover 126 and are supplied with cutting fluid from a cutting fluid source (not shown). The shower nozzle 128 has a nozzle facing the tip of the cutting edge 124 of the cutting blade 121 in the X-axis direction and supplies cutting fluid from the nozzle to the tip of the cutting edge 124 of the cutting blade 121 during cutting.

[0032] The blade nozzles 129 extend parallel to the X-axis direction and are spaced apart from each other in the Y-axis direction. The blade nozzles 129 position the lower end of the cutting edge 124 of the cutting blade 121 between them and have nozzles (not shown) facing the lower end of the cutting edge 124 of the cutting blade 121. The blade nozzles 129 supply cutting fluid from the nozzles to the lower end of the cutting edge 124 of the cutting blade 121 during cutting.

[0033] 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 image sensor that captures the area to be divided of the workpiece 200 held on the chuck table 110 before cutting. The image sensor is, for example, a CCD (Charge-Coupled Device) image sensor or a CMOS (Complementary MOS) image sensor having multiple pixels. The imaging unit 130 captures the surface 201 of the workpiece 200 held on the chuck table 110 with the image sensor through the objective lens.

[0034] The imaging unit 130 photographs the workpiece 200 held on the chuck table 110 to acquire an image for performing alignment, which involves positioning the workpiece 200 and the cutting blade 121, and outputs the acquired image to the control unit 170.

[0035] Furthermore, the cutting device 100 includes an X-axis position detection unit (not shown) for detecting the X-axis position of the chuck table 110, a Y-axis position detection unit (not shown) for detecting the Y-axis position of the cutting unit 120, a Z-axis position detection unit for detecting the Z-axis position of the cutting unit 120, and an angle detection unit for detecting an 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 or Y-axis and a reading head. The Z-axis position detection unit detects the Z-axis position of the cutting unit 120 using motor pulses. The angle detection unit is configured with a well-known rotary encoder or the like.

[0036] 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 position of the cutting unit 120 in the Y-axis direction or Z-axis direction to the control unit 170. The angle detection unit outputs the angle of the chuck table 110 around its axis from a reference position to the control unit 170. In Embodiment 1, the positions of each component of the cutting device 100 in the X-axis, Y-axis, and Z-axis directions are determined based on a predetermined reference position (not shown).

[0037] The cutting device 100 also includes a cassette elevator 150 on which a cassette 151 containing workpieces 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 storage container capable of accommodating multiple workpieces 200 at intervals in the Z-axis direction and is equipped with an loading / unloading port 152 for loading and unloading the workpieces 200. The cassette elevator 150 is positioned next to one side in the Y-axis direction of the chuck table 110 located in the loading / unloading area, and the loading / unloading port 152 is positioned on the side of the chuck table 110 located in the loading / unloading area, on which the cassette 151 is placed.

[0038] The cleaning unit 160 is used to clean the workpiece 200 after cutting. The cleaning unit is positioned next to the chuck table 110 located in the loading / unloading area, on the other side in the Y-axis direction, and is positioned in line with the cassette 151 and the chuck table 110 located in the loading / unloading area in the Y-axis direction. The cleaning unit 160 includes a spinner table 161 for suction holding the workpiece and a cleaning fluid supply nozzle 162 for supplying cleaning fluid to the surface 201 of the workpiece 200 held by the spinner table 161.

[0039] The transport unit transports the workpiece 200 across the cassette 151, the chuck table 110, and the spinner table 161 of the washing unit 160.

[0040] The control unit 170 controls each component of the cutting device 100 to cause the cutting device 100 to perform machining operations on the workpiece 200. The control unit 170 is a computer having a arithmetic processing unit with a microprocessor such as a CPU (central processing unit), a storage device with memory such as ROM (read-only memory) or RAM (random access memory), and an input / output interface device. The arithmetic processing unit of the control unit 170 performs calculations according to the computer program stored in the storage device and outputs control signals for controlling the cutting device 100 to each component of the cutting device 100 via the input / output interface device.

[0041] The control unit 170 is connected to a display unit (not shown) which consists of a liquid crystal display device that displays the status of machining operations and images, an input unit used by the operator to register machining conditions, and a notification unit. The input unit consists of at least one of a touch panel provided on the display unit and an external input device such as a keyboard. The notification unit notifies the operator by emitting at least one of sound and light.

[0042] Furthermore, the control unit 170 includes a machining control unit 171. The machining control unit 171 controls each of the above-mentioned components of the cutting device 100 to cause each component of the cutting device 100 to perform machining operations on the workpiece 200. The function of the machining control unit 171 is realized by the arithmetic processing unit performing calculations according to a computer program stored in the memory device.

[0043] Furthermore, the cutting device 100 includes a cutting blade detection mechanism 1, which is partially shown in Figure 3. The cutting blade detection mechanism 1 detects the state of the cutting edge 124 of the cutting blade 121. In this 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 indicating the wear state of the cutting edge 124, and whether or not the cutting edge 124 is chipped all the way around.

[0044] (Cutting blade detection mechanism) As shown in Figure 3, the cutting blade detection mechanism 1 comprises a mechanism body 2, multiple light-emitting means, namely light-emitting bodies 10, and multiple light-receiving means, namely light-receiving bodies 20. The mechanism body 2 is attached to the blade cover 126 and positioned above the cutting blade 121. The mechanism body 2 has a pair of vertical parts 3 spaced apart along the Y-axis and each extending in the Z-axis direction, between which the cutting edge 124 of the cutting blade 121 is positioned, and a connecting part 4 connecting the upper ends of the vertical parts 3. The mechanism body 2 forms a blade entry part 5 between the pair of vertical parts 3, into which the cutting edge 124 of the cutting blade 121 is inserted. That is, the cutting blade detection mechanism 1 is equipped with a blade entry part 5.

[0045] The main body of the mechanism 2 has an adjustment screw 6 that is screwed into a threaded hole in the blade cover 126 and attached to the connecting part 4. When the adjustment screw 6 is rotated around the axis by an operator or the like, the main body of the mechanism 2 moves along the Z-axis direction relative to the blade cover 126, and the radial position of the cutting edge 124 of the cutting blade 121 relative to the blade cover 126 is adjusted.

[0046] Multiple light-emitting elements 10 are arranged on one side of the vertical section 3 (hereinafter referred to as reference numeral 3-1) in the Y-axis direction, which is the rotation axis of the cutting blade 121. As shown in Figures 3 and 4, the multiple light-emitting elements 10 are arranged adjacent to each other in series in the radial direction of the cutting edge 124 of the cutting blade 121. The multiple light-emitting elements 10 face the other side of the vertical section 3 (hereinafter referred to as reference numeral 3-2) and are arranged on a straight line along the Z-axis direction, that is, along the radial direction of the cutting edge 124 of the cutting blade 121. The light-emitting elements 10 are the ends of optical fibers 12 connected to the light-emitting element 11 shown in Figure 5, and they irradiate the light 13 emitted by the light-emitting element 11 toward the other side of the vertical section 3-2. The light-emitting element 11 is, for example, an LED (Light-Emitting Diode) or an LD (Laser Diode).

[0047] Multiple photodetectors 20 are arranged on the vertical section 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 photodetectors 20 are arranged adjacent to each other in series in the radial direction of the cutting edge 124 of the cutting blade 121 on the other side of the vertical section 3-2. The multiple photodetectors 20 are arranged on the other side of the vertical section 3-2 facing the vertical section 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, and face the multiple light-emitting elements 10.

[0048] Each photodetector 20 corresponds one-to-one with a light-emitting element 10 and faces the corresponding light-emitting element 10 along the Y-axis direction, which is the rotation axis of the cutting blade 121. The photodetectors 20 are at the ends of the optical fiber 22 and each receives light 13 emitted by at least its corresponding light-emitting element 10. In this embodiment, the photodetectors 20 also receive light 13 from light-emitting elements 10 other than their corresponding light-emitting element 10. In Embodiment 1, the amount of light 13 received by the end photodetectors 20 among the multiple arranged photodetectors is less than the amount of light 13 received by the central photodetector 20.

[0049] In Embodiment 1, 16 light-emitting elements 10 and 16 light-receiving elements 20 are arranged in each of the vertical sections 3-1 and 3-2. Also, in Embodiment 1, since the light-emitting elements 10 and 20 are arranged in the vertical sections 3-1 and 3-2, the blade entry section 5 is formed between the multiple light-emitting elements 10 and the multiple light-receiving elements 20.

[0050] Furthermore, as shown in Figure 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. Thus, in Embodiment 1, the control unit 170 controls the machining operation of the entire cutting device 100 and also constitutes the cutting blade detection mechanism 1. However, in the present invention, the control means that constitute the cutting blade detection mechanism 1 may be provided separately from the control unit 170 which controls the machining operation of the entire cutting device 100.

[0051] The photoelectric converter 30 converts the light 13 received by each of the multiple photodetectors 20 into a signal 31 with a voltage value corresponding to the amount of light 13. In Embodiment 1, multiple photoelectric converters 30 are provided, each corresponding to a photodetector 20 on a one-to-one basis. The photoelectric converter 30 is connected to the other end of an optical fiber 22, the end of which is a photodetector 20, and is connected to the corresponding photodetector 20. That is, in Embodiment 1, the same number of photoelectric converters 30 are provided as the number of light-emitting elements 10. The photoelectric converter 30 receives the light 13 received by the corresponding photodetector 20 via the optical fiber 22, converts the light 13 received by the corresponding photodetector 20 into a signal 31 with a voltage value corresponding to the amount of light, and outputs the converted signal 31 to the amplifier 40.

[0052] The amplifier 40 adjusts the voltage value of the signal 31 output from the photoelectric converter 30. Multiple amplifiers 40 are provided, each corresponding one-to-one with the photodetector 20 and the photoelectric converter 30. That is, in Embodiment 1, the same number of amplifiers 40 are provided as the number of light emitters 10, photodetectors 20 and photoelectric converters 30. The amplifier 40 adjusts the voltage value of the signal 31 output from the corresponding photoelectric converter 30 and outputs the adjusted signal 41 to the transmittance calculation unit 174 of the control unit 170.

[0053] In Embodiment 1, the functions of the photoelectric converter 30 and the amplifier 40 are realized by dedicated processing circuits (hardware) such as a single circuit, a composite circuit, a programmed processor, or a parallel programmed processor.

[0054] Furthermore, 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 Figure 5.

[0055] The high-voltage value identification unit 172 identifies the highest voltage value among the voltage values ​​of each signal 31 output from the photoelectric converter 30 when the cutting edge 124 of the cutting blade 121 is not inside the blade entry portion 5. The high-voltage value identification unit 172 identifies the highest voltage value among the voltage values ​​of the signal 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.

[0056] The amplifier adjustment unit 173 adjusts the amplifier 40 so that the voltage values ​​of each signal 41 become 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 voltage value adjustment becomes the highest voltage value identified by the high voltage value identification unit 172; in other words, it causes the amplifier 40 to adjust the voltage value of each signal 41 to the highest voltage value identified by the high voltage value identification unit 172.

[0057] The transmittance calculation unit 174 sums the voltage values ​​of the signals 41 output from all amplifiers 40, calculates the transmittance of the light 13 received by the photodetector 20 based on the summed voltage value, and detects the state of the cutting edge 124 of the cutting blade 121. Transmittance is a value that is set to 100 percent when all photodetectors 20 receive the light 13 and 0 percent when none of the photodetectors 20 receive the light 13, that is, it is a value that indicates the proportion of light 13 irradiated by multiple light emitters 10 that has passed through the blade penetration area 5. In short, transmittance is a value that increases as the cutting edge 124 of the cutting blade 121 that has entered the blade penetration area 5 wears down, and increases periodically when a part of the cutting edge 124 of the cutting blade 121 that has entered the blade penetration area 5 is chipped.

[0058] The functions of the high-voltage value identification unit 172, the amplifier adjustment unit 173, and the transmittance calculation unit 174 are realized by the arithmetic processing unit performing calculations according to a computer program stored in the memory device.

[0059] In the cutting device 100 with the configuration described above, the voltage value of the signal 41 output by each amplifier 40 of the cutting blade detection mechanism 1 is adjusted as shown below, at the time of factory shipment, during periodic maintenance, etc. When the voltage value is adjusted, the cutting device 100 irradiates light 13 from multiple light emitters 10 to multiple photodetectors 20 without the cutting blade 121 being mounted on the spindle 123. Each photoelectric converter 30 of the cutting device 100 converts the light 13 from the light emitters 10 received by each photodetector 20 into a signal 31, and outputs the converted signal 31 to the amplifier 40.

[0060] In Embodiment 1, the photoelectric converter 30 converts the light 13 received by the photodetectors 20 located at both ends of the plurality of photodetectors 20 (hereinafter referred to as reference numeral 20-1) into a signal 31 with a voltage of 10 mV and outputs it to the amplifier 40. Also in Embodiment 1, the photoelectric converter 30 converts the light 13 received by the photodetector 20 adjacent to photodetector 20-1 (hereinafter referred to as reference numeral 20-2) into a signal 31 with a voltage of 12 mV and outputs it to the amplifier 40. In Embodiment 1, the photoelectric converter 30 converts the light 13 received by the remaining photodetectors 20 into a signal 31 with a voltage of 13 mV and outputs it to the amplifier 40.

[0061] Then, the cutting device 100's 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 Embodiment 1, the high-voltage value identification unit 172 identifies the highest voltage value as 13mV.

[0062] 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 Embodiment 1, the amplifier adjustment unit 173 adjusts the voltage values ​​of all signals 41 output by the amplifier 40 to 13mV. In this way, the voltage values ​​of the signals 41 output by the amplifier 40 of the cutting blade detection mechanism 1 are adjusted in the cutting device 100.

[0063] Furthermore, in the cutting device 100, the machining control unit 171 controls each of the above-mentioned components of the cutting device 100, and during the machining operation in which the workpiece 200 held in the chuck table 110 is cut with the cutting blade 121 while supplying cutting fluid, multiple light emitters 10 of the cutting blade detection mechanism 1 irradiate light 13 toward 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, if the cutting blade detection mechanism 1 detects that part or all of the cutting edge 124 of the cutting blade 121 has been chipped, the machining control unit 171 of the control unit 170 stops the machining operation and activates the notification unit to notify the operator.

[0064] As described above, in the cutting blade detection mechanism 1 according to Embodiment 1, the high voltage value identification unit 172 identifies the highest voltage value among the voltage values ​​of the signals 31 converted by the photoelectric converter 30, and 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 this way, in the cutting blade detection mechanism 1 according to Embodiment 1, the amplifier adjustment unit 173 adjusts the amplifier 40 so that the voltage values ​​of each signal 41 become uniform based on the highest voltage value identified by the high voltage value identification unit 172, thereby equalizing the voltage values ​​of the signals 41 input to the transmittance calculation unit 174. As a result, the sum of the voltage values ​​of all signals 41 input to the transmittance calculation unit 174 can be brought closer to a value corresponding to the position of the tip of the cutting edge 124 of the cutting blade 121 in the blade entry portion 42.

[0065] As a result, the cutting blade detection mechanism 1 according to Embodiment 1 reduces the influence of variations in the amount of light 13 received by each of the multiple photodetectors 20, enabling high-precision detection of the cutting blade 121. In other words, it has the effect of suppressing a decrease in the detection accuracy of the state of the cutting edge 124 of the cutting blade 121.

[0066] It should be noted that the present invention is not limited to the embodiments described above. That is, it can be implemented with various modifications without departing from the core principles of the present invention. [Explanation of symbols]

[0067] 1. Cutting blade detection mechanism 5. Blade entry point 10. Light-emitting element (light-emitting means) 13 light 20. Photodetector (light-receiving means) 30 Photoelectric Converters 40 Amplifier 100 Cutting equipment 110 Chuck Table 121 Cutting Blades 124 cutting edge 170 Control unit (control means) 172 High Voltage Value Identification Section 173 アンプ Adjustment Department 200 Workpieces

Claims

[Claim 1] A cutting blade detection mechanism for a cutting device comprising: a plurality of light-emitting means arranged adjacent to each other in series in the radial direction of a cutting blade having an annular cutting edge for cutting a workpiece held on a chuck table that holds a workpiece; a plurality of light-receiving means disposed opposite to the plurality of light-emitting means on the other side of the cutting blade in the rotation 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 photoelectric converter that converts the light received by each of the plurality of light-receiving means into a voltage value corresponding to the amount of light; An amplifier that adjusts the voltage value output from the photoelectric converter, It has control means, The control means is, A high-voltage value identification unit that identifies the highest voltage value among the voltage values ​​output from the photoelectric converter when the cutting blade is not present in the blade entry area, An amplifier adjustment unit adjusts the amplifier so that each of the voltage values ​​becomes uniform based on the highest voltage value identified by the high voltage value identification unit. A cutting blade detection mechanism that includes the above, reduces the influence of variations due to the amount of light received by each of the multiple light receiving means, and enables high-precision detection of the cutting blade.

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