Blade breakage detection device and blade breakage detection method

Abstract

To provide a blade breakage detection device and a blade breakage detection method which can improve machining efficiency on a workpiece.SOLUTION: A light quantity received by a light detection unit 50 is determined by an A / D converter 88, which serves as a high-resolution light quantity determination section. The shape of chipping occurring with a blade tip 12A of a blade 12 is detected on the basis of a determination result of the A / D converter 88.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a blade breakage detection device and a blade breakage detection method for detecting chipping of the cutting edge of a blade mounted on a dicing device. [Background technology]

[0002] Dicing machines are known as machines for dividing workpieces, such as semiconductor wafers on which semiconductor devices or electronic components are formed, into individual chips. These dicing machines are equipped with a blade that rotates at high speed using a spindle, a table that holds the workpiece by suction, and X, Y, Z, and θ movement axes that change the relative position between the table and the blade. The dicing machine uses the high-speed rotating blade to groove or cut the workpiece, which is held by suction on the table and moves relatively using the movement axes.

[0003] In such dicing machines, if a large processing load is placed on the blade when processing a workpiece, the blade's cutting edge may chip during processing. If processing continues with a blade with a chipped cutting edge, processing cannot be performed reliably and the workpiece may be damaged.

[0004] To solve this problem, the dicing machine disclosed in Patent Document 1 is provided with a blade breakage detection device having a light-emitting unit and a light-receiving unit near the side of the blade. This blade breakage detection device detects blade breakage based on changes in the amount of light received by the light-receiving area of ​​the light-receiving unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-310396 Summary of the Invention [Problem to be solved by the invention]

[0006] When a conventional blade breakage detection device detects blade damage (chips in the cutting edge), the dicing machine will, for example, turn on a warning light to notify the operator that the blade is broken, and the operator will then stop the dicing machine and replace the blade.

[0007] On the other hand, depending on the size of the chip that occurs on the blade edge, there may be cases where continuing processing with that blade without replacing the blade does not affect processing accuracy. However, conventional blade breakage detection devices determine that the blade is broken when a chip occurs on the cutting edge, regardless of the size of the chip, so the dicing device must be stopped even when there is no need to replace the blade, resulting in a problem of reduced workpiece processing efficiency.

[0008] The present invention has been made in view of the above circumstances, and has an object to provide a blade breakage detection device and a blade breakage detection method that can improve the efficiency of workpiece processing. [Means for solving the problem]

[0009] In order to solve the above problems, the blade breakage detection device of the present invention comprises a light detection unit having a light-projecting section that projects light toward the blade and a light-receiving section that is arranged opposite the light-projecting section across the blade and receives the light projected from the light-projecting section, and a chip detection section that includes a high-resolution light intensity determination section that can determine with high resolution the amount of light received by the light-receiving section, and that detects the shape of a chip that occurs on the cutting edge of the blade based on the determination result of the high-resolution light intensity determination section.

[0010] According to one aspect of the blade breakage detection device of the present invention, the light preferably has a cross-sectional shape that is elongated in the radial direction of the blade.

[0011] According to one aspect of the blade breakage detection device of the present invention, it is preferable to further include a determination unit that determines whether or not replacement of the blade is necessary based on the detection result of the chipping detection unit.

[0012] According to one embodiment of the blade breakage detection device of the present invention, it is preferable that the judgment unit judges whether or not blade replacement is necessary based on the result of comparing the shape of the chip detected by the chip detection unit with a shape threshold.

[0013] According to one embodiment of the blade breakage detection device of the present invention, it is preferable that the chip detection unit detects at least one of a first length in the radial direction of the chipped blade and a second length in the circumferential direction of the blade as a dimension length indicating the shape of the chip.

[0014] According to one embodiment of the blade breakage detection device of the present invention, it is preferable that the chipping detection unit detects a first length and a second length as dimensional lengths, and the determination unit determines whether or not the blade needs to be replaced based on the result of comparing the first length with a first threshold value and the result of comparing the second length with a second threshold value.

[0015] In order to solve the above problems, the blade breakage detection device of the present invention comprises a light detection unit having a light-projecting section that projects light toward the blade and a light-receiving section that is arranged opposite the light-projecting section across the blade and receives the light projected from the light-projecting section, and a chip detection section that includes a high-resolution light intensity determination section that can determine with high resolution the amount of light received by the light-receiving section, and that detects the area of ​​any chips that occur on the cutting edge of the blade based on the determination result of the high-resolution light intensity determination section.

[0016] According to one aspect of the blade breakage detection device of the present invention, the light preferably has a cross-sectional shape that is elongated in the radial direction of the blade.

[0017] According to one aspect of the blade breakage detection device of the present invention, it is preferable to further include a determination unit that determines whether or not replacement of the blade is necessary based on the detection result of the chipping detection unit.

[0018] According to one embodiment of the blade breakage detection device of the present invention, it is preferable that the judgment unit judges whether or not blade replacement is necessary based on the result of comparing the area of ​​the chip detected by the chip detection unit with an area threshold.

[0019] In order to solve the above problem, the blade breakage detection method of the present invention includes a light detection step in which light is projected from one of the opposing sides of the blade and received on the other side, and a chip detection step in which the amount of light received in the light detection step is determined by a high-resolution light intensity determination unit and the shape of a chip that has occurred on the cutting edge of the blade is detected based on the determination result of the high-resolution light intensity determination unit.

[0020] According to one embodiment of the blade breakage detection method of the present invention, it is preferable to include a light detection step in which light is projected from one of the opposing sides of the blade and received on the other side, and a chip detection step in which the amount of light received in the light detection step is determined by a high-resolution light intensity determination unit and the area of ​​any chipping that has occurred on the cutting edge of the blade is detected based on the determination result of the high-resolution light intensity determination unit.

[0021] According to one aspect of the blade breakage detection method of the present invention, the light preferably has a cross-sectional shape that is elongated in the radial direction of the blade.

[0022] According to one aspect of the blade breakage detection method of the present invention, it is preferable to further include a determination step of determining whether or not replacement of the blade is necessary based on the detection result of the chipping detection step. [Effects of the Invention]

[0023] According to the present invention, the efficiency of machining a workpiece can be improved. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is an overall perspective view of a dicing machine equipped with a blade breakage detection device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the structure of the processing unit. [Figure 3] FIG. 3 is a perspective view showing the structure of the tip of a spindle provided with a blade breakage detection device. [Figure 4] FIG. 4 is an explanatory diagram that schematically shows the structure of the detection unit. [Figure 5] FIG. 5 is a diagram showing various output signals corresponding to four types of chipping that occurred on the cutting edge of the blade. [Figure 6] FIG. 6 is a flowchart showing an example of a method for determining a blade by the blade breakage detection device. DETAILED DESCRIPTION OF THE INVENTION

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a blade breakage detection device and a blade breakage detection method according to the present invention will be described with reference to the accompanying drawings.

[0026] FIG. 1 is an overall perspective view of a dicing device 10 equipped with a blade breakage detection device according to an embodiment. The dicing device 10 shown in FIG. 1 is a so-called twin-spindle dicer, in which a pair of blades 12, 12 are arranged facing each other. The dicing device 10 includes a processing unit 18 having a pair of spindles 14, 14 with built-in high-frequency motors and blades 12 attached to their tips, and a work table 16 on which a workpiece W is placed and which holds the workpiece W by suction. The processing unit 18 cuts (dices) the workpiece W with the blade 12 while moving the workpiece W and the blade 12 relative to each other. Examples of the workpiece W include silicon, silicon carbide, or other semiconductor materials, as well as other materials such as sapphire, glass, and quartz.

[0027] The dicing apparatus 10 has, arranged at predetermined positions, a camera 19 that captures an image of the surface of the workpiece W, a cleaning unit 20 that spin-cleans the processed workpiece W, a load port 22 on which a cassette containing a plurality of workpieces W is placed, and a transport device 24 that transports the workpieces W. The dicing apparatus 10 also has a built-in control unit 26 that controls the overall operation of each unit of the dicing apparatus 10.

[0028] The control unit 26 includes various arithmetic processing circuits including a central processing unit (CPU) (not shown), a memory such as a read-only memory (ROM) or a random access memory (RAM), an input device such as a keyboard, and an output device such as a display unit 46. The control unit 26 realizes the functions of each unit of the control unit 26, including the blade breakage detection device, by the CPU executing a program stored in the memory.

[0029] Figure 2 is a perspective view showing the structure of processing unit 18. Processing unit 18 shown in Figure 2 is equipped with an X table 34. X table 34 is guided by a pair of X guides 30, 30 provided on X base 28, and is driven in the X direction indicated by arrow XX by a linear motor 32. Furthermore, a rotary table 36 that rotates in the θ direction is erected on the upper surface of X table 34, and work table 16 is provided on this rotary table 36. Therefore, work table 16 is moved in the X direction by X table 34, and rotated in the θ direction by rotary table 36.

[0030] Processing unit 18 also includes a gate-shaped Y base 38 that straddles X base 28. A pair of Y tables 42, 42 are provided on the wall surface of Y base 38. The pair of Y tables 42, 42 are guided by a pair of Y guides 40, 40 fixed to the wall surface of Y base 38, and are driven in the Y direction indicated by arrow YY by a drive device made up of a motor and a feed screw device (not shown).

[0031] Z tables 44 are provided on the Y tables 42, respectively. The Z tables 44 are guided by Z guides (not shown) provided on the Y table 42, and are driven in the Z direction indicated by arrow ZZ by a drive device (not shown) made up of a motor and a feed screw device. Spindles 14 are fixed to the Z tables 44, facing each other, and blades 12 attached to the tips of the spindles 14 are arranged facing each other in the Y direction.

[0032] With the above-described configuration of the processing unit 18, the blades 12, 12 are indexed in the Y direction and cut in the Z direction, while the work table 16 is cut in the X direction and rotated in the θ direction. These operations are controlled by the control unit 26 (see FIG. 1). Note that the X direction refers to one direction in the horizontal direction, and the Y direction refers to a direction perpendicular to the X direction in the horizontal direction. The Z direction refers to a vertical direction perpendicular to the X and Y directions, and the θ direction refers to a rotation direction around a vertical axis.

[0033] Returning to FIG. 1, the dicing device 10 has a display unit 46. The display unit 46 is connected to the control unit 26 and displays the results of the dicing process, the state of the blade 12 such as chipping, and various other data. If a display panel with a touch panel is used as the display unit 46, the operator of the dicing device 10 can use the touch panel to input data such as processing conditions and threshold values ​​for determining the state of the blade 12 to the control unit 26.

[0034] Incidentally, if an excessive load is applied to the blade 12 while cutting the workpiece W with the blade 12, a chip may occur on the cutting edge 12A of the blade 12 (see FIG. 3 ), which may affect the processing quality of the workpiece W. For example, if the depth or length of the chip is equal to or greater than a predetermined value, sufficient processing accuracy may not be achieved when cutting the workpiece W with the blade 12, and problems may arise in that the workpiece W may be damaged during the cutting process. On the other hand, if a chip occurs on the cutting edge 12A but the depth or length of the chip is less than a predetermined value, or if the chip is only a small partial loss (for example, a chip with a depth of 1 mm or less), continuing to cut the workpiece W with the blade 12 without replacing the blade 12 may not affect the processing quality.

[0035] For these reasons, when a chip occurs in the cutting edge 12A, it is preferable to detect the state of the chip (at least one of the depth and length of the chip) and determine whether the blade 12 is usable or needs to be replaced based on that state, from the perspective of improving the processing efficiency of the workpiece W. The depth and length of the chip are each dimensional lengths that indicate the shape of the chip. The depth of the chip refers to the length of the chip in the radial direction of the blade 12, in other words, the length from the edge of the chip that is closest to the central axis S of the blade 12 to the outer peripheral edge of the blade 12. This chip depth corresponds to the first length in the present invention. The length of the chip refers to the length of the chip in the circumferential direction of the blade 12, and corresponds to the second length in the present invention.

[0036] Therefore, the dicing device 10 shown in Figure 1 is equipped with a blade breakage detection device 48 (see Figures 3 and 4) for detecting chipping that has occurred on the cutting edge 12A (see Figure 3) and determining the condition of the blade 12.

[0037] Next, a blade breakage detection device 48 according to an embodiment will be described with reference to FIGS.

[0038] Fig. 3 is a perspective view showing the structure of the tip of the spindle 14 provided with an optical detection unit 50 that constitutes part of the blade breakage detection device 48. Fig. 4A is a side view schematically showing the structure of the optical detection unit 50. Also shown in Fig. 4A are a functional block diagram of the optical detection unit 50 and a functional block diagram of a determination unit 52 that constitutes part of the blade breakage detection device 48. Fig. 4B is an explanatory diagram showing the positional relationship between a light receiving unit 70 (described later) and the cutting edge 12A of the blade 12. Below, the blade breakage detection device 48 will be described while explaining the structure of the tip of the spindle 14.

[0039] 3, a wheel cover 54 is attached to the tip of the spindle 14 so as to cover the blade 12. The wheel cover 54 is composed of a front cover portion 56, a rear cover portion 58, a nozzle block 60, a guide block 72, etc. A hose 62 is connected to the rear cover portion 58, and cutting water is supplied from the hose 62. The supplied cutting water is sprayed from a nozzle 63 provided on the wheel cover 54 toward the rotating blade 12. A hose 64 is connected to the nozzle block 60, and cooling water is supplied from the hose 64. The supplied cooling water is sprayed from a pair of nozzles 66, 66 provided on the wheel cover 54 toward the point where the blade 12 is to be machined on the workpiece W.

[0040] As shown in FIG. 4A , the light detection unit 50 has a light-projecting section 68 and a light-receiving section 70. The light-projecting section 68 has a light-projecting area 74, and the light-receiving section 70 has a light-receiving area 76. The light-projecting area 74 and the light-receiving area 76 are arranged along the Y direction on opposite sides of the blade 12. The light-projecting section 68 and the light-receiving section 70 are integrated and supported by a guide block 72 shown in FIG. 3 so as to be movable up and down in the Z direction. The light detection unit 50 is connected to a feed mechanism 53 provided on the wheel cover 54 and is moved up and down in the Z direction by the driving force of the feed mechanism 53. As a result, the light-projecting area 74 of the light-projecting section 68 and the light-receiving area 76 of the light-receiving section 70 are moved integrally forward and backward relative to the rotation center S of the blade 12. An example of the feed mechanism 53 is a feed screw device.

[0041] 4A, an optical cable 80 is connected to the light projecting unit 68, the other end of which is connected to a light source 78. Light from the light source 78 transmitted via the optical cable 80 is projected from the light projecting area 74 of the light projecting unit 68 toward the blade 12.

[0042] On the other hand, an optical cable 84 is connected to the light receiving unit 70 at its other end to a photoelectric conversion unit 86. The light projected from the light projecting unit 68 is received by the light receiving area 76 of the light receiving unit 70 and input to the photoelectric conversion unit 86 via the optical cable 84.

[0043] Here, the light 77A (see FIG. 4B; hereinafter also referred to as the "inspection beam 77A") projected from the light-projecting unit 68 toward the light-receiving unit 70 has, for example, a cross-sectional shape elongated in the radial direction of the blade 12 (a beam cross-sectional shape perpendicular to the optical axis of the inspection beam 77A). By forming the inspection beam 77A in this way, it is possible to increase the dynamic range of the detectable light amount, which is preferable because it becomes possible to detect even minute partial losses. Furthermore, by forming the inspection beam 77A in the above-described elongated cross-sectional shape, the amount of light received by the light-receiving region 76 increases sharply with respect to the time axis at the moment a chip that has occurred on the blade edge 12A is detected, thereby obtaining a highly reproducible chip shape. In other words, when the inspection beam 77A has an elongated cross-sectional shape, it is preferable because the transition of the light amount with respect to the time axis can be detected with high resolution. The above is the configuration of the light detection unit 50.

[0044] Next, a portion of the inspection beam 77A input to the photoelectric conversion unit 86 is converted by the photoelectric conversion unit 86 into an electrical signal having a voltage corresponding to the amount of light received, and the converted signal is input to the A / D converter 88. The A / D converter 88 converts the analog electrical signal into a digital signal using a predetermined sampling frequency (period). For example, the digital signal represents the signal value using a specified number of binary digits. The digital signal output from the A / D converter 88 is input to the determination unit 52. Here, the photoelectric conversion unit 86 and the A / D converter 88 function as a chip detection unit 82 for detecting the shape of a chip in the cutting edge 12A based on a change in the amount of light received by the light receiving unit 70.

[0045] The A / D converter 88 has a high time resolution, and the sampling frequency is set to about several MHz (e.g., 1.5 MHz). In the chipping detection unit 82, the amount of light received by the light-receiving unit 70 is determined with high resolution by the A / D converter 88, enabling accurate detection of the shape (depth and length) of the chip in the blade 12. The A / D converter 88 corresponds to the high-resolution light-amount determination unit of the present invention, and is capable of determining the amount of light with such high resolution that the shape of the chip in the cutting edge 12A can be detected from changes in the amount of light received by the light-receiving unit 70. The sampling frequency is set based on the rotation speed and diameter of the blade 12, the circumferential length of the chip to be determined, and other factors.

[0046] As a method for determining the light intensity with high resolution, in addition to the method of increasing the sampling frequency set in the A / D converter 88 to acquire an electrical signal indicating chipping during one blade rotation, as described above, there is also the following method. That is, for each rotation of the blade, the sampling phase is shifted by the width of the inspection beam 77A, and the resulting signal values ​​for each sample are combined in the circumferential direction to acquire an electrical signal indicating chipping for one rotation of the blade 12. Furthermore, by synchronously adding the electrical signals, it is possible to reduce noise components caused by, for example, water (cutting water and cooling water) sprayed during machining. As a result, it is possible to effectively extract only the electrical signal indicating chipping.

[0047] Next, a description will be given of the determination unit 52. The determination unit 52 determines whether or not the blade 12 needs to be replaced based on the detection result of the chipping detection unit 82.

[0048] The determination by the determination unit 52 is performed during cutting of the workpiece W. In this case, the blade 12 is rotated at a high speed of, for example, about 60,000 rpm, and the determination is made as to whether or not there is a chip of about several hundred microns.

[0049] Next, we will temporarily suspend the explanation of the determination unit 52 and explain the table shown in Fig. 5. This table shows the shapes of four types of chips 13A, 13B, 13C, and 13D that have occurred on the cutting edge 12A of the blade 12, as well as examples of analog signals and signal values ​​corresponding to these chip shapes.

[0050] Specifically, column A of Fig. 5 shows an enlarged view of the shapes of the four types of notches 13A to 13D, and column B shows analog signals (waveform signals showing the time changes in the electrical signals output from the photoelectric conversion unit 86) corresponding to the shapes of the notches 13A to 13D. The analog signals are determined by the amount of light that passes through the notches 13A to 13D out of the amount of light of the inspection beam 77A projected from the light projector 68. Column C shows numerical values ​​(2 to 9) that have been quantized by the A / D converter 88 from the analog signals corresponding to the shapes of the notches 13A to 13D, and column D shows a schematic diagram in the form of a bar graph representing each of the quantized numerical values.

[0051] The signals shown in columns B to D of FIG. 5 are obtained based on the light intensity of the inspection beam 77A, which has a cross-sectional shape elongated in the radial direction of the blade 12, as shown in column A. Meanwhile, column E shows an analog signal corresponding to the shape of the chips 13A to 13D obtained based on the light intensity of the inspection beam 77B, which has a circular cross-sectional shape. Column F shows an analog signal corresponding to the shape of the chips 13A to 13D obtained based on the light intensity of the inspection beam 77B. Comparing the analog signal shown in column F with the analog signal shown in column B, it can be seen that the light intensity when the inspection beam 77A, which has a cross-sectional shape elongated in the radial direction of the blade 12, increases sharply with time at the moment the chips 13A to 13D are detected, compared to the light intensity when the circular inspection beam 77B is used. Therefore, as described above, by using the inspection beam 77A, which has a cross-sectional shape elongated in the radial direction of the blade 12, the transition of the light intensity with respect to the time axis can be detected with high resolution. This enables the chipping detection unit 82 to more accurately detect the shape of the chips.

[0052] When chips 13A-13D occur on the cutting edge 12A (see column A), a portion of the light from the inspection beam 77A projected from the light projector 68 passes through the chips 13A-13D, causing the voltage value of the electrical signal output from the photoelectric converter 86 to rise in accordance with the shape of the chips 13A-13D (see column B). The waveform of each electrical signal then exhibits a waveform corresponding to the depth and length of the chips 13A-13D. The height of the waveform corresponds to the depth of the chips 13A-13D (corresponding to the "first length"), and the width of the waveform corresponds to the length of the chips 13A-13D (corresponding to the "second length"). This makes it possible to determine the depth of the chips 13A-13D based on the value indicating the height of the waveform (see column C), and the length of the chips 13A-13D based on the time axis indicating the width of the waveform (see column B). In other words, the chip detector 82 can detect the shape of the chips 13A-13D from the depth and length of the chips 13A-13D.

[0053] Therefore, the determination unit 52 shown in FIG. 4A determines whether the blade 12 needs to be replaced based on the shape of the chip detected by the chip detection unit 82. The determination unit 52 includes a memory unit 90 in which thresholds (depth threshold and length threshold) described below are set, and a comparison unit 92. The memory unit 90 is preset with a depth threshold (corresponding to the "first threshold" among the shape thresholds) determined for the depth of the chip in the blade 12 and a length threshold (corresponding to the "second threshold" among the shape thresholds) determined for the length of the chip. In this example, when determining the depth threshold, a quantized numerical value (see column C in FIG. 5) is used as an index value representing the depth. Furthermore, when determining the length threshold, a value obtained by multiplying the time required for consecutive outputs of values ​​equal to or greater than the depth threshold by the peripheral speed of the blade 12 (the speed in the tangential direction of the cutting edge 12A) is used as an index value representing the length.

[0054] On the other hand, even if a chip occurs in the cutting edge 12A of the blade 12, if the depth or length of the chip is sufficiently small, it may be possible to cut the workpiece W with sufficient accuracy. Therefore, the depth threshold is set as a value equivalent to the upper limit of the chip depth at which it can be determined that the depth of the chip in the blade 12 is sufficiently small and the workpiece W can be cut as is. Furthermore, the length threshold is set as a value equivalent to the upper limit of the length of the chip in the blade 12 is sufficiently small and the workpiece W can be cut as is.

[0055] The depth threshold and length threshold are set in advance by, for example, an operator of the dicing device 10 before cutting the workpiece W. The depth threshold and length threshold differ depending on the material of the workpiece W to be cut, the type of blade 12, and the cutting process to be performed, and each threshold is set each time under the respective conditions.

[0056] When the blade breakage detection device 48 of this embodiment detects chipping of the cutting edge 12A of the blade 12, the light-projecting unit 68 and the light-receiving unit 70 are positioned at a predetermined height by the feed mechanism 53. For example, the height is set near the upper end of the cutting edge 12A of the blade 12 attached to the spindle 14. For example, the height is set at a position where the inspection beam 77A from the light-projecting unit 68 is blocked by the blade 12 by approximately 90% when no chipping occurs on the cutting edge 12A. As a result, even when no chipping occurs on the cutting edge 12A, the light-receiving unit 70 receives approximately 10% of the light from the inspection beam 77A from the light-projecting unit 68. This approximately 10% of the light appears as the value "2" in column C of FIG. 5 . In other words, in this embodiment, when the A / D converter 88 outputs a value of "3" or greater, the determining unit 52 determines that a chip has occurred on the cutting edge 12A. It should be noted that the proportion of the inspection beam 77A from the light projecting unit 68 that is blocked by the blade 12 when no chipping occurs in the blade 12 is not limited to this example (90%).

[0057] Next, the operation of the blade breakage detection device 48 according to the embodiment will be described.

[0058] First, in the dicing machine 10 equipped with the blade breakage detection device 48, a calibration operation is performed by lightly contacting the rotating blade 12 with the surface of the work table 16, recording the distance from the origin position of the blade 12 to the work table 16, and simultaneously recording the amount of light received by the light receiving area 76. Then, the cutting feed amount of the blade 12 in the Z direction and other parameters are adjusted based on the value obtained in the calibration operation, the thickness of the work W that has been input in advance, the outer diameter of the blade 12, and other data.

[0059] When the calibration work is completed, cutting of the workpiece W by the blade 12 is started, and the blade breakage detection device 48 starts to judge the blade 12 .

[0060] Here, a method for determining the blade 12 by the blade breakage detection device 48 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing an example of a method for determining the blade 12 by the blade breakage detection device 48. This determination method is a method for determining the blade 12 based on both the depth and length of chipping that has occurred on the cutting edge 12A of the blade 12.

[0061] First, a depth threshold value (for example, the number "6") determined for the depth of the chip and a length threshold value determined for the length of the chip are set in the storage unit 90 (S100: threshold value setting step). After this threshold value setting step (S100) is executed, cutting of the workpiece W by the blade 12 is started.

[0062] Next, the optical detection unit 50 executes an optical detection step in which the light projecting section 68 projects the inspection beam 77A and the light receiving section 70 receives the inspection beam 77A (S110).

[0063] Next, chipping detection unit 82 executes a chipping detection step (S120) in which the shape of a chip that has occurred on cutting edge 12A of blade 12 is detected. That is, in chipping detection step (S120), the amount of light received in light detection step (S110) is determined by A / D converter 88, and the shape of a chip that has occurred on cutting edge 12A of blade 12, as shown in column A in Fig. 5, is detected based on the determination result of A / D converter 88 (temporal change in light intensity due to light amount).

[0064] Next, the determining unit 52 executes a determining step (S130) of determining whether or not replacement of the blade 12 is necessary based on the detection result of the chip shape in the chip detection step (S120). This will be specifically described below.

[0065] In the determination step (S130), it is determined based on the depth threshold and the length threshold whether or not the blade 12 having the chip shape (depth and length) detected in the chip detection step (S120) needs to be replaced (i.e., whether or not the blade 12 is usable). For example, if the depth of the chip detected in the chip detection step (S120) is less than the depth threshold and the length of the chip is less than the length threshold, the determination step (S130) determines that the blade 12 is usable (i.e., a YES determination). The display unit 46 then displays the determination result in the determination step (S130) (blade usable). Thereafter, until it is determined in the determination step (S130) that the blade 12 needs to be replaced, cutting of the workpiece W continues, and the chip detection step (S120) and the determination step (S130) are repeatedly performed.

[0066] On the other hand, for example, if at least one of the depth and length of the chip detected in the chip detection step (S120) is equal to or greater than the respective threshold value, a determination step (S130) is made that the blade 12 needs to be replaced (i.e., a "No" determination). The display unit 46 then displays the determination result (blade replacement required) in the determination step (S130). Furthermore, the operator is notified by, for example, turning on the warning light 94 shown in FIG. 4A. Upon receiving this notification, the operator begins the blade replacement work. It should be noted that if a "No" determination is made in the determination step (S130), the cutting of the workpiece W may be automatically interrupted or stopped.

[0067] As described above, the blade breakage detection device 48 of this embodiment includes an A / D converter 88 (high-resolution light intensity determination unit) that can determine with high resolution the amount of light received by the light detection unit 50, and is able to detect the shape of a chip that has occurred on the cutting edge 12A of the blade 12 based on the result (light intensity determination result) output from the A / D converter 88. This makes it possible to determine the condition of the blade 12 (whether or not the blade 12 needs to be replaced, i.e., whether or not the blade 12 is usable) from the shape of a chip that has occurred on the cutting edge 12A of the blade 12, thereby avoiding unnecessary stops of the dicing device 10. As a result, the processing efficiency of the workpiece W can be improved.

[0068] Furthermore, according to the blade breakage detection device 48 of the embodiment, even if a chip occurs on the cutting edge 12A of the blade 12, if the shape of the chip (depth and length) is below the respective thresholds, the blade 12 is not replaced unnecessarily, thereby saving (reducing) the amount of blade 12 used. Furthermore, if multiple chips occur along the outer periphery of the blade 12, it is preferable to determine the condition of the blade 12 based on the deepest or longest chip among the multiple chips. Alternatively, a threshold may be set to the sum of the peak values ​​for each depth or the sum of the respective lengths, and the condition of the blade 12 may be determined based on these thresholds. Furthermore, even if the detected depth and length are below the respective thresholds, it is preferable to monitor the depth and length on the display unit 46. This allows the current condition of the blade 12 to be constantly monitored, making it possible to predict, for example, when to replace the blade.

[0069] In the above example of the method for determining blade 12, the state of blade 12 is determined based on both the depth and length of the chipping that has occurred on cutting edge 12A of blade 12, but as another example, the state of blade 12 may be determined based on the depth (first length) of the chipping that has occurred on cutting edge 12A of blade 12. As another example, the state of blade 12 may be determined based on the length of the chipping that has occurred on cutting edge 12A of blade 12. Either determination method can avoid unnecessary stops of dicing apparatus 10, thereby improving the processing efficiency of workpiece W.

[0070] Furthermore, according to the blade breakage detection device 48 of this embodiment, it is possible to detect the shapes of chips 13A to 13D, such as those shown in column A of Fig. 5, as the shape of chips that have occurred on the cutting edge 12A of the blade 12, and it is therefore possible to detect the area of ​​the chip using the detection results. Here, for example, chip 13A is detected as a rectangular shape that is shallower than a certain reference depth value and shorter than a certain reference length value, chip 13B is detected as a rectangular shape that is shallower than a certain reference depth value and longer than a certain reference length value, chip 13C is detected as a rectangular shape that is deeper than a certain reference depth value and shorter than a certain reference length, and chip 13D is detected as a triangular shape with varying depths, a deep maximum depth, and a short maximum length.

[0071] That is, for rectangular chips 13A to 13C, the area can be detected as the product of depth and length, and for triangular chip 13D, the area can be detected as half the product of depth and length. In this case, a quantized value (a value equal to or greater than 3: see column C in Figure 5) is used as an index value representing depth, and a value obtained by multiplying the peripheral speed of blade 12 by the time when the above-mentioned values ​​equal to or greater than 3 are output consecutively is used as an index value representing length.

[0072] From this perspective, another example of a method for determining the condition of the blade 12 using the blade breakage detection device 48 is a method based on the area of ​​chipping that has occurred on the cutting edge 12A of the blade 12. The above-mentioned method for determining the condition of the blade 12 based on the area will now be described with reference to the flowchart of FIG.

[0073] First, before cutting the workpiece W with the dicing device 10, an area threshold determined for the area of ​​chipping is set in the storage unit 90 (S100: threshold setting step). After this threshold setting step is executed, cutting of the workpiece W with the blade 12 is started.

[0074] Next, the optical detection unit 50 executes an optical detection step in which the light projecting section 68 projects the inspection beam 77A and the light receiving section 70 receives the inspection beam 77A (S110).

[0075] Next, chipping detection unit 82 executes a chipping detection step (S120) in which the area of ​​a chip that has occurred on cutting edge 12A of blade 12 is detected. That is, in chipping detection step (S120), the amount of light received in light detection step (S110) is determined by A / D converter 88, and based on the determination result of A / D converter 88, the area of ​​a chip that has occurred on cutting edge 12A of blade 12 as shown in column A in Fig. 5 is detected.

[0076] Next, the determining unit 52 executes a determining step (S130) of determining whether or not replacement of the blade 12 is necessary based on the result of detection of the chipped area in the chipped detection step (S120). This will be specifically described below.

[0077] In the determination step (S130), it is determined based on the area threshold whether or not the blade 12 having the chipped area detected in the chipping detection step (S120) needs to be replaced (i.e., whether or not the blade 12 is usable). For example, if the area of ​​the chipped part detected in the chipping detection step (S120) is less than the area threshold, the determination step (S130) determines that the blade 12 is usable (i.e., a YES determination). The display unit 46 then displays the determination result (blade usable) in the determination step (S130). Thereafter, until it is determined in the determination step (S130) that the blade 12 needs to be replaced, cutting of the workpiece W continues, and the chipping detection step (S120) and the determination step (S130) are repeatedly performed.

[0078] On the other hand, if the area of ​​the chip detected in the chip detection step (S120) is equal to or greater than the area threshold, a determination is made in the determination step (S130) that the blade 12 needs to be replaced (i.e., a No determination is made). The display unit 46 then displays the determination result in the determination step (S130) (blade replacement required). The operator is notified, for example, by turning on the warning light 94 shown in FIG. 4A. Upon receiving this notification, the operator begins the blade replacement work. It should be noted that if a No determination is made in the determination step (S130), the cutting of the workpiece W may be automatically interrupted or stopped.

[0079] Even when the area of ​​chipping occurring on the cutting edge 12A of the blade 12 is detected in this way, it is possible to determine the condition of the blade 12 (whether or not the blade 12 needs to be replaced, i.e., whether or not the blade 12 is usable) based on the detected area, thereby avoiding unnecessary stops of the dicing device 10. As a result, the processing efficiency of the workpiece W can be improved.

[0080] Furthermore, even in the above-described method of judging the condition of the blade 12 based on the area, if multiple chips have occurred along the outer periphery of the blade 12, it is preferable to judge the condition of the blade 12 based on the chip with the largest area among the multiple chips. Alternatively, an area threshold may be set to the value obtained by adding up the areas of each chip, and the condition of the blade 12 may be judged based on that threshold. Furthermore, even if the detected area is less than the area threshold, it is preferable to monitor the area on the display unit 46. This allows the current condition of the blade 12 to be constantly monitored, making it possible to predict, for example, when to replace the blade.

[0081] In the above embodiment, the light detection unit 50 uses the inspection beam 77A that is elongated in the radial direction of the blade 12, and the inspection beam 77A is irradiated from the light-projecting unit 68 toward the light-receiving unit 70. However, the present invention is not limited to this configuration. For example, a slit plate having a slit hole formed therein that is elongated in the radial direction of the blade 12 may be disposed between the light-projecting unit 68 and the light-receiving unit 70, so that the light-receiving unit 70 can receive light having a cross-sectional shape that is elongated in the radial direction of the blade 12. As another example, the light-receiving area 76 of the light-receiving unit 70 may be configured to be elongated in the radial direction of the blade 12. Furthermore, the shape of the inspection beam 77A is not limited to a cross-sectional shape that is elongated in the radial direction of the blade 12. As long as the high-resolution light intensity determining unit (e.g., the A / D converter 88) can determine the inspection beam with high resolution, the cross-sectional shape of the inspection beam may be other shapes (e.g., circular).

[0082] Furthermore, in this embodiment, the configuration includes the light-receiving unit 70, which is disposed opposite the light-projecting unit 68 across the blade 12 and receives the light projected from the light-projecting unit 68. However, the present invention is not limited to this. For example, the light-projecting unit 68 and the light-receiving unit 70 may be disposed on the same side of the blade 12, with the light-receiving unit 70 receiving the light projected from the light-projecting unit 68 and reflected by the blade 12. In this case, in areas of the blade 12 without chips, a large amount of the light projected from the light-projecting unit 68 is received by the light-receiving unit 70. On the other hand, in areas of the blade 12 where chips exist, the amount of light reflected by the blade 12 is reduced, and therefore the amount of light received by the light-receiving unit 70 is less than the above-mentioned light. As a result, this configuration can similarly detect the shape and area of ​​chips by increasing or decreasing the amount of light, which is the opposite of the configuration in which the light-receiving unit 70 is disposed opposite the light-projecting unit 68 across the blade 12 and receives the light projected from the light-projecting unit 68.

[0083] An example of a blade breakage detection device according to the present invention has been described above, but the technology of the present invention is not limited to the embodiment, and several improvements or modifications may be made within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0084] 10... dicing device, 12... blade, 12A... cutting edge, 13A to 13D... chipping, 14... spindle, 16... work table, 18... processing unit, 19... camera, 20... cleaning unit, 22... load port, 24... conveying device, 26... control unit, 30... X guide, 32... linear motor, 34... X table, 36... rotary table, 38... Y base, 40... Y guide, 42... Y table, 44... Z table, 46... display unit, 48... blade breakage detection device, 50... optical detection unit, 52... judgment unit, 53... feed mechanism, 54... Yield cover, 56...front cover, 58...rear cover, 60...nozzle block, 62...hose, 63...nozzle, 64...hose, 66...nozzle, 68...light-emitting unit, 70...light-receiving unit, 72...guide block, 74...light-emitting area, 76...light-receiving area, 77A...inspection beam (light), 77B...inspection beam, 78...light source, 80...optical cable, 82...chip detection unit, 84...optical cable, 86...photoelectric conversion unit, 88...A / D converter (high-resolution light intensity judgment unit), 90...storage unit, 92...comparison unit, 94...warning light

Claims

1. A blade breakage detection device that is applied to a processing device that cuts a workpiece by rotating a circular blade, a light detection unit including a light projecting unit that projects light toward the blade, and a light receiving unit that is disposed opposite the light projecting unit across the blade and receives the light projected from the light projecting unit; a chipping detection unit including a high-resolution light intensity determination unit having a sampling frequency set to several MHz or more that can determine the amount of light received by the light receiving unit with high resolution, and detecting the shape of a chip on the cutting edge of the blade caused by the cutting process based on the determination result of the high-resolution light intensity determination unit; A blade breakage detection device comprising:

2. The blade breakage detection device according to claim 1 , wherein the light has a cross-sectional shape in which a radial length along the radial direction of the blade is longer than a circumferential length along the circumferential direction of the blade.

3. The blade breakage detection device according to claim 1 or 2, further comprising a determination unit that determines whether or not replacement of the blade is necessary based on a detection result from the chipping detection unit.

4. The blade breakage detection device according to claim 3 , wherein the determination unit determines whether or not replacement of the blade is necessary based on a result of comparing the shape of the chip detected by the chip detection unit with a shape threshold value.

5. 5. The blade breakage detection device according to claim 4, wherein the chipping detection unit detects at least one of a first length of the chipping in the radial direction of the blade and a second length of the chipping in the circumferential direction of the blade as a length dimension indicating the shape of the chipping.

6. the chipping detection unit detects the first length and the second length as the dimensional length, 6. The blade breakage detection device according to claim 5, wherein the determination unit determines whether or not replacement of the blade is necessary based on a result of comparing the first length with a first threshold value and a result of comparing the second length with a second threshold value.

7. A blade breakage detection device that is applied to a processing device that cuts a workpiece by rotating a circular blade, a light detection unit including a light projecting unit that projects light toward the blade, and a light receiving unit that is disposed opposite the light projecting unit across the blade and receives the light projected from the light projecting unit; a chipping detection unit including a high-resolution light intensity determination unit having a sampling frequency set to several MHz or more that can determine the amount of light received by the light receiving unit with high resolution, and detecting the area of ​​chipping of the cutting edge of the blade caused by the cutting process based on the determination result of the high-resolution light intensity determination unit; A blade breakage detection device comprising:

8. The blade breakage detection device according to claim 7 , wherein the light has a cross-sectional shape in which a radial length along the radial direction of the blade is longer than a circumferential length along the circumferential direction of the blade.

9. The blade breakage detection device according to claim 7 or 8, further comprising a determination unit that determines whether or not replacement of the blade is necessary based on a detection result from the chipping detection unit.

10. The blade breakage detection device according to claim 9 , wherein the determination unit determines whether or not replacement of the blade is necessary based on a result of comparing an area of ​​the chip detected by the chip detection unit with an area threshold.

11. A blade breakage detection method performed in a blade breakage detection device applied to a processing device that rotates a circular blade to cut a workpiece, The blade breakage detection device includes a light detection unit having a light emitting unit and a light receiving unit, and a chipping detection unit, a light detection step of projecting light from the light projecting unit provided on one side of the blade and receiving the light with the light receiving unit provided on the other side; a chip detection step in which a high-resolution light intensity determination unit having a sampling frequency set to several MHz or more determines the amount of light received in the light detection step, and the chip detection unit detects the shape of a chip in the cutting edge of the blade caused by the cutting process based on the determination result of the high-resolution light intensity determination unit; A blade breakage detection method comprising:

12. A blade breakage detection method performed in a blade breakage detection device applied to a processing device that rotates a circular blade to cut a workpiece, The blade breakage detection device includes a light detection unit having a light emitting unit and a light receiving unit, and a chipping detection unit, a light detection step of projecting light from the light projecting unit provided on one side of the blade and receiving the light with the light receiving unit provided on the other side; a chipping detection step in which a high-resolution light intensity determination unit having a sampling frequency set to several MHz or more determines the amount of light received in the light detection step, and the chipping detection unit detects the area of ​​a chip in the cutting edge of the blade caused by the cutting process based on the determination result of the high-resolution light intensity determination unit; A blade breakage detection method comprising:

13. The blade breakage detection method according to claim 11 or 12, wherein the light has a cross-sectional shape in which a radial length along the radial direction of the blade is longer than a circumferential length along the circumferential direction of the blade.

14. The blade breakage detection method according to claim 11 , further comprising a determination step of determining whether or not replacement of the blade is necessary based on a detection result of the chipping detection step.

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