Blade breakage detection device

Abstract

The present invention provides a blade damage detection device that can detect chipping that has occurred on only one side of the outer circumference of a blade. [Solution] A blade damage detection device for detecting damage to a rotatable blade 102, comprising: a light emitting unit 26 which is a light emitting means that irradiates light R obliquely with respect to the rotation axis C toward only the corner of the outer peripheral portion 102R of the blade 102 which is formed by the outer peripheral surface of the blade 102 and one of the two sides (first surface 102a, second surface 102b) in the axial direction of the rotation axis C of the blade 102; a light receiving unit 28 which is a light receiving means that receives light R irradiated from the light emitting means and transmitted through the outer peripheral portion 102R of the blade 102; and a detection means (control unit) which detects damage to the corner of the blade 102 based on the light receiving result of the light receiving means.

Description

Technical Field

[0001] The present invention relates to a blade breakage detection device that irradiates a blade with light to detect breakage of the blade.

Background Art

[0002] A dicing device that divides a wafer having a plurality of devices formed on its surface into individual chips includes a blade that is rotated at high speed by a spindle and a table that adsorbs and holds the wafer. In the dicing process among the semiconductor manufacturing processes, the blade of the dicing device is rotated at high speed, and grooving or cutting is performed on the wafer adsorbed and held by the table.

[0003] In addition, in the dicing process, a grinder process for thinly grinding the wafer may be provided. When the wafer is thinly ground in the grinder process, the outer peripheral portion of the wafer may become a knife edge, and this knife edge may cause processing defects. Therefore, in order to prevent the generation of the knife edge, a process called edge trimming may be provided in which step processing is performed on the outer peripheral portion of the wafer with a blade.

[0004] Here, when edge trimming is performed, depending on the amount of edge removal, a blade thicker than normal may be used. Also, even when processing the surface of the wafer by rotating the blade as normally performed in the dicing process, a thick blade may be used for the purpose of forming the shape of the groove itself rather than for the purpose of dividing the wafer into chips for each chip. The thickness of a normally used blade is several μm, but the thickness of the above-mentioned thick blade is 1 mm to 5 mm.

[0005] Here, various techniques for detecting breakage of the blade of a dicing device have been proposed. For example, in Patent Document 1, a blade breakage detection device is described that emits light from a light emitting unit and receives the light at a light receiving unit, and detects breakage of the blade according to the amount of the received light. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2009-83077 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The blade damage detection device described in Patent Document 1 employs a configuration in which light is emitted from a light-emitting unit parallel to the rotation axis of the blade, and this light is received by a light-receiving unit. However, with such a configuration, if, for example, a chip occurs only on one side of the outer circumference of a thick blade, the chip may not be detected.

[0008] Furthermore, conventionally, inspections for chipping on the outer edge of the front or back surface of the thick blade were only performed after a defect occurred in a diced product. This inspection involved workers visually checking the condition of the blade with a microscope to detect chipping. In this way, when workers visually detect blade damage, the blade must be removed from the dicing machine, which prevents the machine from operating and reduces productivity. In addition, because workers only check the blade after a defect occurs in a diced product, there is a risk of producing a large number of defective products.

[0009] This invention has been made in view of these circumstances, and its objective is to provide a damage detection device that can detect chipping that has occurred on only one side of the outer circumference of a blade. [Means for solving the problem]

[0010] A blade breakage detection device, which is one aspect of the present invention for achieving the above objective, is a blade breakage detection device for detecting breakage of a rotatable blade, comprising: a light irradiation means that irradiates light obliquely with respect to the rotation axis of the blade toward the outer circumference of the blade; a light receiving means that receives light irradiated from the light irradiation means and transmitted through the outer circumference of the blade; and a detection means that detects blade breakage based on the light receiving result of the light receiving means.

[0011] According to this embodiment, light is shone obliquely to the axis of rotation of the blade toward the outer circumference of the blade. This makes it possible to detect chipping that has occurred on only one side of the outer circumference of the blade.

[0012] Preferably, the light irradiation means has a light-emitting element that emits light having an optical axis that extends from one end to the other, straddling the outer circumference of the blade.

[0013] Preferably, the inclination angle of the optical axis with respect to the rotation axis of the blade is in the range of 30 to 60 degrees.

[0014] Another embodiment of the present invention is a blade breakage detection device for detecting breakage of a rotatable blade, comprising: a light irradiation means that irradiates the outer periphery of the blade with light that has passed through a first lens having an optical axis parallel to the rotation axis of the blade; a light receiving means that receives light that has passed through a second lens facing the outer periphery of the blade and having the same optical axis as the first lens; and a detection means that detects blade breakage based on the light receiving result of the light receiving means.

[0015] According to this embodiment, light passing through the first lens is directed toward the outer periphery of the blade, and light passing through the second lens is received. As a result, this embodiment can detect chipping that has occurred on only one side of the outer periphery of the blade.

[0016] Preferably, the numerical aperture (NA) of the first and second lenses is 0.4 or greater.

[0017] Preferably, the focal positions of the first lens and the second lens are located at the center of the width direction of the blade.

Advantages of the Invention

[0018] According to the present invention, it is possible to detect a chip that has occurred only on one side of the outer peripheral portion of the blade.

Brief Description of the Drawings

[0019] [Figure 1] FIG. 1 is a perspective view showing the appearance of a dicing device equipped with a blade breakage detection device. [Figure 2] FIG. 2 is a perspective view showing the configuration of the processing unit. [Figure 3] FIG. 3 is a perspective view showing the tip structure of the spindle. [Figure 4] FIG. 4 is a schematic structural diagram showing the structure of a detection unit according to an embodiment that is a premise of the present invention. [Figure 5] FIG. 5 is a diagram for explaining the chip forms of a thin blade and a thick blade. [Figure 6] FIG. 6 is a diagram for explaining the detection unit of the blade breakage detection device. [Figure 7] FIG. 7 is a functional block diagram of a control unit that controls the operation of the blade breakage detection device. [Figure 8] FIG. 8 is a diagram showing the received light voltage detected by the received light amount detection unit. [Figure 9] FIG. 9 is a diagram for explaining another example of the detection unit of the blade breakage detection device. [Figure 10] FIG. 10 is a diagram for explaining the detection unit of the blade breakage detection device. [Figure 11] FIG. 11 is a diagram for explaining the detection unit of the blade breakage detection device.

Embodiments for Carrying Out the Invention

[0020] <0000-103>A preferred embodiment of the blade breakage detection device according to the present invention will be described below with reference to the attached drawings.

[0021] Figure 1 is a perspective view showing the external appearance of a dicing apparatus equipped with the blade breakage detection device 10 of the present invention.

[0022] The dicing apparatus 100 includes a processing unit 110 having a pair of spindles 106, 106 arranged opposite each other, and a work table 108 for suction and holding the workpiece W. The dicing apparatus 100 also includes a cleaning unit 112 for spin-cleaning the processed workpiece W, a load port 114 for placing a cassette containing multiple workpieces W, a transport device 116 for transporting the workpieces W, and a control unit 118 for overall control of the operation of each unit.

[0023] The spindle 106 described above is, for example, a spindle with a built-in high-frequency motor, and a blade 102 for cutting the workpiece W is attached to the tip of the spindle 106. The blade 102 is rotated at high speed by the spindle 106, for example, at 8000 rpm to 60000 rpm.

[0024] Blade 102 is a cutting blade configured in a disc shape. Blade 102 can be an electroplated blade with diamond abrasive grains or CBN (Cubic Boron Nitride) abrasive grains electroplated with nickel, or a resin blade bonded with resin. The blade 102 is typically thick, ranging from 1 mm to 5 mm. The diameter of the blade 102 is, for example, 50 mm.

[0025] Figure 2 is a perspective view showing the configuration of the processing unit 110.

[0026] The machining unit 110 shown in Figure 2 has an X-table 126. This X-table 126 is guided by an X-guide 122 provided on the X-base 120 and is driven in the X-axis direction shown by XX in Figure 2 by a linear motor 124. A rotary table 128 that rotates around the Z-axis is mounted on this X-table 126, and a work table 108 is provided on this rotary table 128.

[0027] Furthermore, the machining section 110 has a Y-base 130. This Y-base 130 is provided so as to straddle the linear motor 124. On the side of the Y-base 130 is a Y-table 134, which is guided by a Y-guide 132 and driven in the Y-axis direction shown by YY in Figure 2 by a drive device (not shown). Each Y-table 134 is provided with a Z-table 136, which is driven in the Z-axis direction by a drive means (not shown). A spindle 106, with a blade 102 attached to its tip, is fixed to the Z-table 136. With this structure of the machining section 110, the blade 102 is indexed and fed in the Z-axis direction, and the work table 108 is cut and fed in the X-axis direction. Note that the X, Y, and Z axes are mutually orthogonal axes, the X and Y axes are horizontal axes, and the Z axis is vertical (up and down) axis.

[0028] Figure 3 is a perspective view showing the tip structure of the spindle 106.

[0029] As shown in Figure 3, a wheel cover 15 is attached to the tip of the spindle 106, covering the upper part of the blade 102. This wheel cover 15 is constructed by assembling components such as a front cover 16, a rear cover 18, and a nozzle block 20, and has the function of suppressing the scattering of cutting chips, cutting fluid, and cooling water generated during the machining of the workpiece W.

[0030] The end of a hose 21 is connected to the upper surface of the rear part 18 of the cover, and cutting fluid is supplied from the hose 21. The supplied cutting fluid is sprayed from a nozzle 23 provided on the wheel cover 15 toward the rotating blade 102. In addition, the end of a hose 22 is connected to the upper surface of the nozzle block 20, and cooling water is supplied from the hose 22. The supplied cooling water is sprayed from a pair of L-shaped nozzles 24, 24, which are positioned opposite each other on either side of the blade 102 toward the rotating blade 102 and the workpiece W.

[0031] The wheel cover 15 configured as described above is provided with a detection unit 12 that constitutes the blade breakage detection device 10, and a feed mechanism 14 that moves the detection unit 12 in the Z-axis direction. The blade breakage detection device 10 consists of the detection unit 12 and the control unit 118 (see Figures 1 and 7).

[0032] Next, the structure of the detection unit 12 will be described in detail. In the following description, an embodiment that serves as a premise for explaining the present invention will first be shown in Figure 4, and then the present invention will be described.

[0033] Figure 4 is a diagram showing an example of a detection unit 12 based on an embodiment of the present invention, and is a schematic structural diagram showing the structure of the detection unit 12. In Figure 4, a schematic structural diagram of the detection unit 12 is shown as viewed from the X-axis direction in Figure 3.

[0034] As shown in Figure 4, the detection unit 12 consists of a light-emitting section 26 and a light-receiving section 28. In the example shown in Figure 4, the light-emitting section 26 and the light-receiving section 28 are integrally formed by the detection unit body 12A at the upper part of the Z-axis of the blade 102, and the light-emitting surface 36 and the light-receiving surface 44 are arranged opposite each other so as to sandwich the blade 102.

[0035] The light-emitting unit 26 includes a light-emitting element 30 made of a light-emitting diode or laser diode, an optical cable 32 that transmits light from the light-emitting element 30, a light-emitting optical path section 26A through which the light emitted from the optical cable 32 passes, and a right-angle prism 34 attached to the lower part of the light-emitting optical path section 26A that reflects and emits the light transmitted by the light-emitting optical path section 26A. The light-emitting end face of the right-angle prism 34 is formed as the light-emitting surface 36 of the light-emitting unit 26. This light-emitting surface 36 is spaced apart from the side surface of the blade 102.

[0036] The light-receiving unit 28 includes a light-receiving element 38 such as a photodiode, an optical cable 40 connected to the light-receiving element 38, a light-receiving optical path section 28A through which light incident from the right-angle prism 42 passes, and a right-angle prism 42 attached to the lower part of the light-receiving optical path section 28A and connected to the optical cable 40. The light-incident end face of the right-angle prism 42 is formed as the light-receiving surface 44 of the light-receiving unit 28. This light-receiving surface 44 is spaced apart from the side surface of the blade 102.

[0037] The light-emitting surface 36 and the light-receiving surface 44 are positioned opposite each other, sandwiching the outer circumference 102R, which is the cutting edge of the blade 102. The configuration is such that light emitted from the light-emitting surface 36 toward the light-receiving surface 44 that is not obstructed by the outer circumference 102R is incident on the light-receiving surface 44. The light incident on the light-receiving surface 44 is received by the light-receiving element 38. Based on the amount of light received by the light-receiving element 38, the control unit 118 (see Figure 1), described later, detects damage to the blade 102.

[0038] As shown in Figure 4, in the embodiment that forms the basis of the present invention, the optical axis portion La between the light-emitting surface 36 and the light-receiving surface 44 in the optical axis L of the detection unit 12 is set to be parallel to the rotation axis C of the blade 102. That is, the optical axis L of the light irradiated onto the outer circumference 102R of the blade 102 is parallel to the rotation axis C of the blade 102, and the light emitted from the light-emitting surface 36 is irradiated toward the outer circumference 102R of the blade 102 in a direction parallel to the rotation axis C of the blade 102.

[0039] Here, we will explain the problems in the embodiments that form the basis of the present invention.

[0040] Figure 5 illustrates the morphology of chipping between a thin blade and a thick blade. Note that in Figure 5, the light-emitting unit 26 and light-receiving unit 28 constituting the detection unit 12 are shown in a simplified manner. Furthermore, the thickness of each blade is exaggerated in the illustration for clarity.

[0041] In Figure 5, reference numeral 202 shows a schematic diagram illustrating a chip in the thin blade 210, and reference numeral 204 shows a schematic diagram illustrating a chip in the thick blade 102. In both reference numeral 202 and 204, the optical axis L of the detection unit 12 (corresponding to the optical axis portion La between the light-emitting surface 36 and the light-receiving surface 44 in Figure 4) is parallel to the rotation axis C of the blade 210. The light R emitted from the light-emitting section 26 is a beam-shaped light with a diameter of 1 mm to 2 mm.

[0042] As indicated by reference numeral 202, if a chip Q1 occurs in the thin blade 210, the light R emitted from the light-emitting unit 26 passes through the location of the chip Q1 on the blade 210 without being obstructed by the blade 210 during one rotation and is received by the light-receiving unit 28. Therefore, if a chip Q1 exists in the blade 210, a peak M (see Figure 7) is detected in the amount of light received by the light-receiving unit 28 by rotating the blade 210. As a result, the blade damage detection device 10 can detect the chip Q1.

[0043] On the other hand, reference numeral 204 indicates a case where a chip Q2 occurs on the outer periphery 102R of the thick blade 102. In this case, the chip Q2 occurs only on the first surface 102a side of the outer periphery 102R of the blade 102. In such a case, even if the light R emitted from the light-emitting unit 26 hits the location where the chip Q2 has occurred, it is blocked by the second surface 102b (the back surface of the first surface) of the blade 102 and is not received by the light-receiving unit 28. Therefore, even if a chip Q2 exists on the blade 102, the light-receiving unit 28 cannot receive the light R emitted from the light-emitting unit 26 even at the location where the chip Q2 exists, and the light-receiving unit 28 cannot detect a peak M in the amount of light it receives.

[0044] In the case of a thick blade 102, chipping Q2 may occur only on the first surface 102a or the second surface 102b. However, as shown in Figure 5, chipping Q2 cannot be detected even when light parallel to the rotation axis C of the blade 102 is shone onto the outer circumference 102R of the blade 102. Therefore, in the embodiments of the present invention described below (first and second embodiments), it is possible to detect chipping Q2 that has occurred only on one side (first surface 102a or second surface 102b) of the outer circumference 102R of a thick blade 102.

[0045] <First Embodiment> A first embodiment of the blade breakage detection device 10 of the present invention will be described below. In the following description, the differences from the embodiment that serves as the premise for the present invention (particularly the detection unit 12 described in Figure 4) will be explained.

[0046] Figure 6 is a diagram illustrating the detection unit 12 of the blade breakage detection device 10. In Figure 6, the light-emitting unit 26 and the light-receiving unit 28 are shown in a simplified manner, similar to Figure 5, and the light R emitted from the light-emitting unit 26 is a beam-shaped light with a diameter φ of 1 to 2 mm. Furthermore, the light-emitting unit 26 described below is the light irradiation means of the present invention, and the light-receiving unit 28 is the light-receiving means of the present invention.

[0047] As shown in Figure 6, in the detection unit 12 of the first embodiment, the optical axis L of the light R irradiated onto the outer periphery 102R of the blade 102 is inclined obliquely with respect to the rotation axis C of the blade 102. That is, the light R emitted from the light-emitting unit 26 is configured to be irradiated onto the outer periphery 102R of the blade 102 in an oblique direction with respect to the rotation axis C of the blade 102. By irradiating the outer periphery 102R of the blade 102 from the light-emitting unit 26 with light R having an optical axis L inclined obliquely with respect to the rotation axis C of the blade 102, the light is received by the light-receiving unit 28 at the location of the chip Q2 without being obstructed by the blade 102. As a result, the blade damage detection device 10 can detect chip Q2 that has occurred only on one side (first surface 102a) of the outer periphery 102R of the blade 102.

[0048] Here, the inclination angle α of the optical axis L with respect to the rotation axis C is preferably in the range of 30 to 60 degrees. The inclination angle α refers to the angle of inclination of the optical axis L with respect to the rotation axis C (corresponding to the optical axis portion La between the light-emitting surface 36 and the light-receiving surface 44 in Figure 4) when the blade 102 is viewed from the X-axis direction, as shown in Figure 4. By setting the inclination angle α within this range, the missing part Q2 can be detected with high sensitivity without the light R being obstructed by the blade 102. Furthermore, by setting the inclination angle α to approximately 45 degrees, the missing part Q2 can be detected with even higher sensitivity. Here, the optical axis L is the optical axis that indicates the optical path of the light R from the light-emitting surface 36 of the light-emitting unit 26 (see Figure 4) to the light-receiving surface 44 of the light-receiving unit 28 (see Figure 4).

[0049] Figure 7 is a functional block diagram of the control unit 118 that controls the operation of the blade breakage detection device 10. Although the control unit 118 controls the entire dicing device 100, Figure 7 only shows the functional part that controls the operation of the blade breakage detection device 10.

[0050] The control unit 118 includes a light-receiving amount detection unit 62 that detects the amount of light received by the light-receiving element 38 (see Figure 4) at unit time intervals, and a damage detection unit 64 that detects damage to the blade 102 based on the detection results of the light-receiving amount detection unit 62. The control unit 118 is configured to include one or more processors, including a CPU (Central Processing Unit) and an FPGA (field-programmable gate array), and one or more memories. The control unit 118 corresponds to the detection means of the present invention.

[0051] Figure 8 shows the light-receiving voltage detected by the light-receiving quantity detection unit 62.

[0052] Figure 8 shows the received voltage when the detection unit 12 shown in Figure 6 receives light transmitted through the missing Q2.

[0053] When the blade 102 rotates at a predetermined cycle, a peak M of the received voltage, caused by light passing through the chip Q2 and being received by the light receiving unit 28, can be periodically obtained. The light receiving element 38 constituting the light receiving unit 28 outputs a received voltage corresponding to the amount of light received. The damage detection unit 64 then detects the damage (chip Q2) of the blade 102 by detecting this periodically obtained peak M. Therefore, the blade damage detection device 10 can automatically detect the chip Q2 of the blade 102 by having the light receiving amount detection unit 62 output a received voltage corresponding to the amount of light received, and by having the damage detection unit 64 detect the peak M.

[0054] As described above, in the detection unit 12 of the blade damage detection device 10 of this embodiment, the optical axis L of the light R irradiated onto the outer circumference 102R of the blade 102 is configured to be inclined at an angle with respect to the rotation axis C of the blade 102, so that it is possible to detect chipping that has occurred on only one side of the outer circumference 102R of the blade 102.

[0055] In the above description, the case of detecting a chip Q2 occurring on the outer peripheral portion 102R on the first surface 102a side of the blade 102 was described as an example, but the embodiments of this embodiment are not limited to this. For example, as shown in Figure 9, when detecting a chip Q2 occurring on the outer peripheral portion 102R on the second surface 102b side, the optical axis L of the light R irradiated onto the outer peripheral portion 102R of the blade 102 should be tilted in the opposite direction to the configuration shown in Figure 6 with respect to the rotation axis C of the blade 102. That is, the distance between the light-emitting unit 26 and the rotation axis C should be shorter than the distance between the light-receiving unit 28 and the rotation axis C (in other words, the light-emitting unit 26 should be brought closer to the rotation axis C than the light-receiving unit 28), so that the light R irradiated from the light-emitting unit 26 toward the chip Q2 on the first surface 102a side of the blade 102 can be received by the light-receiving unit 28.

[0056] Furthermore, since the surface on the outer periphery 102R of the blade 102 where chipping Q2 is likely to occur (first surface 102a or second surface 102b) tends to follow a certain pattern depending on the usage of the blade 102, for example, two types of detection units (a detection unit corresponding to the configuration shown in Figure 6 and a detection unit corresponding to the configuration shown in Figure 9) with different inclinations of the optical axis L of the light R irradiated onto the outer periphery 102R of the blade 102 may be provided, or these functions may be realized with a single detection unit.

[0057] Furthermore, the embodiment is not particularly limited as long as it has the function of irradiating the outer periphery 102R of the blade 102 with light having an optical axis L that is tilted obliquely with respect to the rotation axis C of the blade 102. For example, the detection unit 12 may be realized by arranging the light-emitting element 30 and the light-receiving element 38 at arbitrary positions and combining a reflective member such as a mirror or prism to guide the light from the light-emitting element 30 to the light-receiving element 38. Alternatively, the detection unit 12 shown in Figure 4 may be realized by tilting it around the X-axis direction.

[0058] Furthermore, the blade damage detection device 10 may be equipped with a tilt mechanism that allows the tilt angle of the detection unit 12 to be varied, and when any detection mode is selected by the user via an operation unit (not shown) from among three detection modes: (1) normal mode (optical axis parallel to blade rotation axis), (2) first surface chip detection mode (corresponding to Figure 6), and (3) second surface chip detection mode (corresponding to Figure 9), the control unit 118 may change the tilt angle α of the detection unit 12 to an angle corresponding to the selected mode and perform damage detection.

[0059] <Second Embodiment> Next, a second embodiment will be described. In the first embodiment described above, the optical axis L of the light R irradiated onto the outer circumference 102R of the blade 102 is configured to be inclined at an angle with respect to the rotation axis C of the blade 102. In contrast, in the second embodiment, a pair of lenses with a high numerical aperture (NA) (light-emitting lens 50 and light-receiving lens 52 (see Figures 10 and 11)) are used to detect chipping that occurs on only one side of the outer circumference 102R of the blade 102.

[0060] Figures 10 and 11 illustrate the detection unit 12 of the blade breakage detection device 10 according to the second embodiment. Note that parts described in Figures 5 and 6 are denoted by the same reference numerals and their descriptions are omitted.

[0061] As shown in Figures 10 and 11, the light-emitting unit 26 has a light-emitting unit-side lens 50, and the light-receiving unit 28 has a light-receiving unit-side lens 52. The light-emitting unit-side lens 50 corresponds to the first lens of the present invention, and the light-receiving unit-side lens 52 corresponds to the second lens of the present invention. The light irradiation means of the present invention includes the light-emitting unit-side lens 50 and is configured to emit light from the light-emitting element 30 (see Figure 4) through the light-emitting unit-side lens 50 by combining it with a reflective member such as a mirror or prism (not shown) or other optical members as needed. The light-receiving means of the present invention includes the light-receiving unit-side lens 52 and is configured to be combined with a reflective member such as a mirror or prism (not shown) or other optical members as needed so that light incident from the light-receiving unit-side lens 52 is received by the light-receiving element 38 (see Figure 4). The light-emitting unit-side lens 50 and the light-receiving unit-side lens 52 have the same lens optical axis S (coinciding with the optical axis L of the detection unit 12), and the lens optical axis S is arranged to be parallel to the rotation axis C of the blade 102. The light-emitting lens 50 and the light-receiving lens 52 are composed of lenses with a high numerical aperture (NA). The light-emitting lens 50 and the light-receiving lens 52 are positioned opposite each other, straddling the outer circumference 102R of the blade 102. The focal positions of the light-emitting lens 50 and the light-receiving lens 52 are located at the center Ra in the width direction of the blade 102.

[0062] As shown in Figure 10, if no chip Q2 occurs in the blade 102, the light incident on the light-emitting lens 50 that passes through the outer periphery of the light-emitting lens 50 (the upper and lower parts of the lens in Figure 10) is blocked by the first surface 102a and the second surface 102b of the blade 102. On the other hand, the light R (shown by an arrow in Figure 10) that passes through the central part of the light-emitting lens 50 is incident on the light-receiving lens 52 and detected by the light-receiving unit 28.

[0063] In contrast, as shown in Figure 11, if the blade 102 has a notch Q2, the light R that passes through a portion of the outer periphery of the light-emitting lens 50 (the lower side of the lens in Figure 11) is blocked by the blade 102. On the other hand, the light R that passes through a portion of the outer periphery of the light-emitting lens 50 (the upper side of the lens in Figure 11) is not blocked by the notch Q2 in the blade 102 and is detected by the light-receiving unit 28 along with the light that passes through the center of the blade 102.

[0064] Therefore, the amount of light detected by the light-receiving unit 28 changes depending on whether or not there is a chip Q2 in the blade 102, making it possible to detect the chip Q2 (damage) of the blade 102 from the detection result. Note that the detection of chip Q2 by a change in the amount of light detected by the light-receiving unit 28 has already been explained with reference to Figures 7 and 8, so it will be omitted here.

[0065] Furthermore, if chipping occurs on both sides of the blade 102 (the first surface 102a and the second surface 102b), the light R that passes through a portion of the outer periphery of the light-emitting lens 50 (the upper and lower sides of the lens in Figure 11) is detected by the light-receiving unit 28 without being obstructed by the blade 102. Therefore, in this case, the amount of light detected by the light-receiving unit 28 is at its largest, making it possible to detect chipping not only on one side of the blade 102 but also on both sides.

[0066] Furthermore, it is preferable that the numerical aperture NA of the light-emitting lens 50 and the light-receiving lens 52 be, for example, 0.4 or more. If the numerical aperture NA of the light-emitting lens 50 and the light-receiving lens 52 is 0.4 or more, the amount of light detected by the light-receiving unit 28 changes according to the occurrence of defects Q2 on the outer circumference 102R of the blade 102, so that defects Q2 can be detected with high accuracy.

[0067] Furthermore, as an example, in Figure 11, if the thickness of the blade 102 is 3 mm, the distance between the blade 102 and the light-emitting lens 50 and the light-receiving lens 52 is 2.25 mm, the lens thickness of the light-emitting lens 50 and the light-receiving lens 52 is 2.5 mm, the focal length of the light-emitting lens 50 and the light-receiving lens 52 is 5 mm, the lens diameter of the light-emitting lens 50 and the light-receiving lens 52 is 5 mm, and the numerical aperture NA = 0.45, then even a chip Q2 of 1 mm or less that occurs on the blade 102 can be detected.

[0068] As described above, in the detection unit 12 of the blade damage detection device 10 of the second embodiment, a pair of light-emitting lenses 50 and light-receiving lenses 52 having a high numerical aperture NA are positioned opposite each other on either side of the outer periphery 102R of the blade 102, and the optical axes S of the pair of light-emitting lenses 50 and light-receiving lenses 52 are positioned parallel to the rotation axis C of the blade 102. As a result, even if a chip Q2 occurs on only one side (first surface 102a or second surface 102b) of the outer periphery 102R of the blade 102, the light R irradiated onto the outer periphery 102R of the blade 102 via the pair of light-emitting lenses 50 and light-receiving lenses 52 having a high numerical aperture NA is received by the light-receiving unit 28, and the amount of light detected by the light-receiving unit 28 changes according to the occurrence of the chip Q2 on the outer periphery 102R of the blade 102. Therefore, according to the second embodiment, similar to the first embodiment, it is possible to detect chipping that occurs only on one side of the outer peripheral portion 102R of the blade 102. Furthermore, it is possible to detect not only chipping that occurs only on one side of the blade 102, but also when chipping occurs on both sides of the outer peripheral portion 102R of the blade 102.

[0069] Although examples of the present invention have been described above, it goes without saying that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. [Explanation of symbols]

[0070] 10…Blade breakage detection device, 12…Detection unit, 14…Feeding mechanism, 15…Wheel cover, 16…Front cover, 18…Rear cover, 20…Nozzle block, 21…Hose, 22…Hose, 23…Nozzle, 24…Nozzle, 26…Light emitting unit, 26A…Light emitting optical path unit, 28…Light receiving unit, 28A…Light receiving optical path unit, 30…Light-emitting element, 32…Optical cable, 34…Right-angle prism, 36…Light emitting surface, 38…Light receiving element, 40…Opti Cal cable, 42...right-angle prism, 44...light-receiving surface, 50...light-emitting lens, 52...light-receiving lens, 62...light-receiving amount detection unit, 64...damage detection unit, 100...dicing device, 102...blade, 102R...outer periphery, 102a...first surface, 102b...second surface, 106...spindle, 108...worktable, 110...processing unit, 112...cleaning unit, 114...load port, 116...conveying device, 118...control unit, C...rotation axis, L...optical axis

Claims

[Claim 1] A blade breakage detection device for detecting breakage of a rotatable blade, A light irradiation means that irradiates light obliquely to the rotation axis only towards the corner of the outer periphery of the blade, which is formed by one of the sides in the axial direction of the rotation axis of the blade and the outer circumferential surface of the blade, A light receiving means that receives light irradiated from the light irradiating means and transmitted through the outer periphery of the blade, A detection means for detecting damage to the corner of the blade based on the light receiving result of the light receiving means, Equipped with, Blade breakage detection device.

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