Cutting apparatus and method for processing workpieces

Abstract

To provide a cutting device that can prevent machining defects caused by incorrect mounting of cutting tools. [Solution] A cutting device for cutting a workpiece, comprising: a holding table for holding the workpiece; a cutting unit having a spindle with a cutting tool attached to its tip for cutting the workpiece held by the holding table; a detection unit having a light irradiating unit and a light receiving unit arranged to sandwich the outer circumference of the cutting tool attached to the cutting unit; and a controller, wherein the outer circumference of the cutting tool is provided with a plurality of protrusions including a first surface for sending out cutting chips generated when the cutting tool cuts the workpiece, and a second surface connected to the first surface; the light irradiating unit irradiates light toward the outer circumference of the cutting tool, the light receiving unit receives the light irradiated from the light irradiating unit, and the controller determines the orientation of the cutting tool attached to the cutting tool based on the amount of light received by the light receiving unit.

Description

[Technical Field]

[0001] The present invention relates to a cutting device for cutting a workpiece, and a method for processing a workpiece by cutting the workpiece with a cutting tool. [Background technology]

[0002] Device chips are manufactured by dividing a wafer on which multiple devices are formed into individual pieces. Furthermore, a package substrate is obtained by mounting multiple device chips onto a base substrate and covering the mounted device chips with a resin-based encapsulant (molding resin). By dividing this package substrate into individual pieces, a package device containing multiple packaged device chips is manufactured. These device chips and package devices are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] Cutting machines are used to divide workpieces such as wafers and package substrates. A cutting machine comprises a holding table that holds the workpiece and a cutting unit that performs cutting on the workpiece. The cutting unit has a built-in spindle, and an annular cutting tool (cutting blade) is attached to the tip of the spindle. The workpiece is held by the holding table, and by rotating the cutting tool and moving the holding table and cutting unit relative to each other (processing feed), the cutting tool cuts into the workpiece, cutting and dividing the workpiece.

[0004] The structure and materials of the cutting tool are appropriately selected according to the material of the workpiece being cut. For example, when cutting and dividing a plate-like object made of raw ceramics, a cutting tool with multiple saw-tooth-like protrusions on its outer circumference may be used (see Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 4-179505 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] As described above, when cutting a workpiece with a cutting tool having a sawtooth-shaped projection, the cutting tool is mounted on the cutting unit in a predetermined orientation. Specifically, the projection has a rake face and a flank face, and the cutting tool is fixed to the tip of the spindle such that the rake face is positioned forward of the flank face in the rotational direction of the cutting tool.

[0007] However, when mounting a cutting tool to the cutting unit, the operator must visually identify the orientation of minute protrusions and mount the cutting tool in the correct orientation while considering the machining feed direction during cutting. As a result, incorrect mounting of the cutting tool is likely to occur. If cutting of the workpiece continues with the cutting tool mounted incorrectly, the workpiece may not be cut as intended, potentially resulting in machining defects.

[0008] Furthermore, for cutting workpieces, a so-called dual-spindle type cutting device is sometimes used, in which a pair of cutting tools are mounted on a pair of cutting units facing each other. In a dual-spindle type cutting device, the orientation of the cutting tools relative to the spindle differs between the pair of cutting units. Therefore, it is easy for operators to misunderstand the correct orientation of the cutting tools, and incorrect mounting of cutting tools is more likely to occur.

[0009] This invention has been made in view of the above problems, and aims to provide a cutting apparatus and a method for processing a workpiece that can prevent the occurrence of processing defects due to incorrect mounting of cutting tools. [Means for solving the problem]

[0010] According to one aspect of the present invention, a cutting apparatus for cutting a workpiece is provided, comprising: a holding table for holding the workpiece; a cutting unit having a spindle on which a cutting tool for cutting the workpiece held by the holding table is attached to the tip; a detection unit having a light irradiating unit and a light receiving unit arranged to sandwich the outer circumference of the cutting tool attached to the cutting unit; and a controller, wherein the outer circumference of the cutting tool is provided with a plurality of protrusions including a first surface for sending out cutting chips generated when the cutting tool cuts the workpiece, and a second surface connected to the first surface; the light irradiating unit irradiates light toward the outer circumference of the cutting tool; the light receiving unit receives the light irradiated from the light irradiating unit; and the controller determines the orientation of the cutting tool attached to the cutting tool based on the amount of light received by the light receiving unit.

[0011] Preferably, the controller determines the orientation of the cutting tool based on the dimensions of the protrusion, which are determined from the amount of light received by the light-receiving unit.

[0012] Furthermore, according to another aspect of the present invention, a method for processing a workpiece by cutting the workpiece with a cutting tool is provided, the cutting tool having a plurality of protrusions on its outer circumference including a first surface for sending out cutting chips generated when the cutting tool cuts the workpiece and a second surface connected to the first surface, a light irradiation unit and a light receiving unit arranged so as to sandwich the outer circumference of the cutting tool mounted on the tip of a spindle, the cutting tool is rotated while irradiating light from the light irradiation unit toward the light receiving unit and measuring the amount of light received by the light receiving unit, a determination step of determining the orientation of the cutting tool based on the amount of light received by the light receiving unit measured in the light amount measurement step, and a cutting step of cutting the workpiece by rotating the cutting tool in a direction such that the first surface is positioned forward in the rotational direction of the second surface, and then cutting the workpiece. [Effects of the Invention]

[0013] In a cutting device and a method for machining a workpiece according to one aspect of the present invention, a light irradiation unit and a light receiving unit are arranged so as to sandwich the outer peripheral portion of a cutting tool, and the orientation of the cutting tool is determined based on the amount of light received by the light receiving unit. As a result, it is possible to avoid continuing the cutting of the workpiece while the cutting tool is mounted in an incorrect orientation, and the occurrence of processing defects due to incorrect mounting of the cutting tool is prevented.

Brief Description of the Drawings

[0014] [Figure 1] It is a perspective view showing a cutting device. [Figure 2] FIG. 2(A) is a front view showing a cutting tool, and FIG. 2(B) is a front view showing a part of the outer peripheral portion of the cutting tool. [Figure 3] It is an exploded perspective view showing a cutting unit. [Figure 4] It is a front view showing a detection unit. [Figure 5] FIG. 5(A) is a side view showing a first cutting unit, and FIG. 5(B) is a side view showing a second cutting unit. [Figure 6] It is a block diagram showing a controller. [Figure 7] FIG. 7(A) is a graph showing the transition of the amount of light received by the light receiving unit when the processing tool is correctly mounted, and FIG. 7(B) is a graph showing the transition of the amount of light received by the light receiving unit when the processing tool is incorrectly mounted. [Figure 8] FIG. 8(A) is a graph showing the contour data of the processing tool in the correctly mounted state, and FIG. 8(B) is a graph showing the contour data of the processing tool in the incorrectly mounted state. [Figure 9] FIG. 9(A) is a graph showing the first contour data to which dimensional calculation processing is applied, and FIG. 9(B) is a graph showing the second contour data to which dimensional calculation processing is applied. [Figure 10] FIG. 10(A) is a graph showing the first contour data to which inclination calculation processing is applied, and FIG. 10(B) is a graph showing the second contour data to which inclination calculation processing is applied.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, an embodiment according to one aspect of the present invention will be described with reference to the attached drawings. First, an example of the configuration of a cutting apparatus according to this embodiment will be described. Figure 1 is a perspective view showing a cutting apparatus 2 that performs cutting on a workpiece 11. In Figure 1, the X-axis direction (machining feed direction, first horizontal direction, front-back direction) and the Y-axis direction (indexing feed direction, second horizontal direction, left-right direction) are perpendicular to each other. Also, the Z-axis direction (up-down direction, height direction, vertical direction) is perpendicular to the X-axis direction and the Y-axis direction.

[0016] The cutting device 2 includes a rectangular parallelepiped base 4 that supports or accommodates each component of the cutting device 2. A rectangular opening 4a is provided at the front corner of the base 4. Inside the opening 4a is a cassette support base 6 that moves up and down by a lifting mechanism (not shown). A cassette 8 capable of accommodating multiple workpieces 11, which are the objects to be processed by the cutting device 2, is placed on the cassette support base 6. In Figure 1, the outline of the cassette 8 is shown by a dashed line.

[0017] For example, the workpiece 11 is a disc-shaped wafer made of a semiconductor material such as single-crystal silicon, and has a front and back surface that are generally parallel to each other. The front surface of the workpiece 11 is divided into multiple rectangular regions by multiple streets (division lines) arranged in a grid pattern so as to intersect each other. Furthermore, devices such as ICs (Integrated Circuits), LSIs (Large Scale Integrations), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) devices are formed in each of the regions divided by the streets. By cutting and dividing the workpiece 11 along the streets with the cutting device 2, multiple device chips, each containing a device, can be obtained.

[0018] However, there are no restrictions on the type, material, shape, structure, size, etc., of the workpiece 11. For example, the workpiece 11 may be a substrate (wafer) made of semiconductors other than silicon (GaAs, InP, GaN, SiC, etc.), glass, sapphire, ceramics, resin, metal, etc. Furthermore, there are no restrictions on the type, quantity, shape, structure, size, arrangement, etc., of the devices, and the workpiece 11 does not even need to have devices formed on it.

[0019] Furthermore, the workpiece 11 may also be a package substrate such as a CSP (Chip Size Package) substrate or a QFN (Quad Flat Non-leaded package) substrate. For example, a package substrate is formed by mounting multiple device chips on a base substrate and sealing the multiple device chips with a resin layer (molding resin). By dividing the package substrate into individual pieces, multiple package devices, each containing multiple packaged device chips, can be manufactured.

[0020] When the workpiece 11 is cut by the cutting device 2, the workpiece 11 is supported by an annular frame 13 for the convenience of handling (transporting, holding, etc.) the workpiece 11. The frame 13 is made of a metal such as SUS (stainless steel), and a circular opening is provided in the center of the frame 13 that penetrates the frame 13 in the thickness direction. The diameter of the frame 13 opening is larger than the diameter of the workpiece 11.

[0021] A circular sheet 15 is fixed to the workpiece 11 and the frame 13. For example, the sheet 15 may be a tape (dicing tape) comprising a film-like base material and an adhesive layer (glue layer) provided on the base material. The base material is made of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate, and the adhesive layer is made of an epoxy, acrylic, or rubber-based adhesive. However, a heat-sealable sheet that does not have an adhesive layer (glue layer) and can be heat-pressed to the workpiece 11 and the frame 13 may also be used as the sheet 15.

[0022] With the workpiece 11 positioned inside the opening of the frame 13, the central part of the sheet 15 is fixed to the back side of the workpiece 11, and the outer periphery of the sheet 15 is fixed to the frame 13. In this way, the workpiece 11 is supported by the frame 13 via the sheet 15. The workpiece 11 is then housed in the cassette 8 while supported by the frame 13.

[0023] A rectangular opening 4b is provided to the side of the opening 4a, with its longitudinal direction aligned with the X-axis. Inside the opening 4b is a holding table (chuck table) 10 for holding the workpiece 11. The upper surface of the holding table 10 is a flat surface that is generally parallel to the horizontal plane (XY plane) and constitutes a holding surface 10a for holding the workpiece 11. The holding surface 10a is connected to a suction source (not shown), such as an ejector, via a flow path (not shown), a valve (not shown), etc., provided inside the holding table 10.

[0024] A moving unit 12 is connected to the holding table 10 to move the holding table 10 along the X-axis direction. For example, the moving unit 12 is a ball screw type moving mechanism and comprises an X-axis ball screw (not shown) arranged along the X-axis direction and an X-axis pulse motor (not shown) that rotates the X-axis ball screw.

[0025] Furthermore, the mobile unit 12 includes a flat table cover 14 that surrounds the holding table 10. In addition, bellows-shaped dustproof and waterproof covers 16 that can be extended and retracted along the X-axis are provided on the front and rear of the table cover 14. The table cover 14 and the dustproof and waterproof covers 16 are installed to close the opening 4b and cover the components of the holding table 10 and the mobile unit 12 that are located inside the opening 4b.

[0026] The holding table 10 is connected to a rotational drive source (not shown), such as a motor, which rotates the holding table 10 around a rotation axis that is approximately parallel to the Z-axis direction. In addition, multiple clamps 18 are provided around the holding table 10 to grip and fix the frame 13 that supports the workpiece 11.

[0027] Near the openings 4a and 4b, a transport mechanism (not shown) is provided for transporting the workpiece 11 between the cassette 8 and the holding table 10. The workpiece 11 is pulled out from the cassette 8 by the transport mechanism and transported to the holding table 10. The workpiece 11 is then placed on the holding surface 10a of the holding table 10 via the sheet 15. The frame 13 is also held by a plurality of clamps 18. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 10a, the workpiece 11 is held by the holding table 10 via the sheet 15.

[0028] Above the holding table 10, cutting units 20a (first cutting unit) and 20b (second cutting unit) for cutting the workpiece 11 are provided. Furthermore, a gate-shaped support structure 22 for supporting the cutting units 20a and 20b is positioned on the upper surface of the base 4 so as to straddle the opening 4b.

[0029] The front surface of the support structure 22 is positioned along the YZ plane. Moving units 24a and 24b are provided at both ends of the front side of the support structure 22. Moving unit 24a is a ball screw type moving mechanism that moves the cutting unit 20a along the Y-axis and Z-axis directions, and moving unit 24b is a ball screw type moving mechanism that moves the cutting unit 20b along the Y-axis and Z-axis directions. Moving units 24a and 24b are mounted on a pair of Y-axis guide rails 26 positioned along the Y-axis direction on the front side of the support structure 22.

[0030] The moving unit 24a includes a flat Y-axis moving plate 28a. The Y-axis moving plate 28a is slidably mounted on a pair of Y-axis guide rails 26. A nut portion (not shown) is provided on the back side (rear side) of the Y-axis moving plate 28a. A Y-axis ball screw 30a, which is positioned along the Y-axis direction between the pair of Y-axis guide rails 26, is screwed into this nut portion. A Y-axis pulse motor 32, which rotates the Y-axis ball screw 30a, is connected to the end of the Y-axis ball screw 30a. When the Y-axis pulse motor 32 rotates the Y-axis ball screw 30a, the Y-axis moving plate 28a moves along the Y-axis direction along the Y-axis guide rails 26.

[0031] A pair of Z-axis guide rails 34a are fixed to the front surface of the Y-axis moving plate 28a along the Z-axis direction. A flat Z-axis moving plate 36a is slidably mounted on the pair of Z-axis guide rails 34a. A nut portion (not shown) is provided on the back surface of the Z-axis moving plate 36a. A Z-axis ball screw 38a, which is positioned between the pair of Z-axis guide rails 34a along the Z-axis direction, is screwed into this nut portion. A Z-axis pulse motor 40a, which rotates the Z-axis ball screw 38a, is connected to the end of the Z-axis ball screw 38a. When the Z-axis ball screw 38a is rotated by the Z-axis pulse motor 40a, the Z-axis moving plate 36a moves along the Z-axis guide rails 34a in the Z-axis direction.

[0032] Similarly, the moving unit 24b includes a flat Y-axis moving plate 28b. The Y-axis moving plate 28b is slidably mounted on a pair of Y-axis guide rails 26. A nut portion (not shown) is provided on the back side (rear side) of the Y-axis moving plate 28b. A Y-axis ball screw 30b, which is positioned along the Y-axis direction between the pair of Y-axis guide rails 26, is screwed into this nut portion. A Y-axis pulse motor (not shown) that rotates the Y-axis ball screw 30b is connected to the end of the Y-axis ball screw 30b. When the Y-axis ball screw 30b is rotated by the Y-axis pulse motor, the Y-axis moving plate 28b moves along the Y-axis guide rails 26 in the Y-axis direction.

[0033] A pair of Z-axis guide rails 34b are fixed to the front surface (front side) of the Y-axis moving plate 28b along the Z-axis direction. A flat Z-axis moving plate 36b is slidably mounted on the pair of Z-axis guide rails 34b. A nut portion (not shown) is provided on the back surface (rear side) of the Z-axis moving plate 36b. A Z-axis ball screw 38b, which is positioned between the pair of Z-axis guide rails 34b along the Z-axis direction, is screwed into this nut portion. A Z-axis pulse motor 40b, which rotates the Z-axis ball screw 38b, is connected to the end of the Z-axis ball screw 38b. When the Z-axis ball screw 38b is rotated by the Z-axis pulse motor 40b, the Z-axis moving plate 36b moves along the Z-axis guide rails 34b in the Z-axis direction.

[0034] The cutting unit 20a is fixed to the lower part of the Z-axis moving plate 36a, and the cutting unit 20b is fixed to the lower part of the Z-axis moving plate 36b. In addition, an imaging unit 42 is provided adjacent to the cutting units 20a and 20b, for imaging subjects such as the workpiece 11 held by the holding table 10.

[0035] The imaging unit 42 includes an image sensor such as a CCD (Charged-Coupled Devices) sensor or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor, and an optical system including optical elements such as an objective lens. The type of imaging unit 42 can be appropriately selected according to the material of the workpiece 11, etc. For example, a visible light camera or an infrared camera can be used as the imaging unit 42. The image acquired by the imaging unit 42 is used for alignment between the workpiece 11 and the cutting units 20a and 20b, etc.

[0036] A circular opening 4c is provided to the side of the opening 4b. Inside the opening 4c is a cleaning unit 44 for cleaning the workpiece 11. The cleaning unit 44 includes a spinner table 46 that holds and rotates the workpiece 11, and a nozzle 48 that supplies cleaning fluid to the workpiece 11 held by the spinner table 46.

[0037] The upper surface of the spinner table 46 is a flat surface that is generally parallel to the horizontal plane (XY plane) and constitutes a holding surface 46a for holding the workpiece 11. The holding surface 46a is connected to a suction source (not shown), such as an ejector, via a flow path (not shown), a valve (not shown), etc., provided inside the spinner table 46. The spinner table 46 is also connected to a rotational drive source (not shown), such as a motor, which rotates the spinner table 46 around a rotation axis that is generally parallel to the Z-axis direction.

[0038] A nozzle 48 for supplying cleaning fluid is positioned above the spinner table 46. For example, the cleaning fluid can be a liquid (such as pure water) or a mixed fluid containing a liquid (such as pure water) and a gas (such as air). With the workpiece 11 held by the spinner table 46, the workpiece 11 is cleaned by supplying cleaning fluid from the nozzle 48 to the workpiece 11 while the spinner table 46 is rotated.

[0039] Near the openings 4b and 4c, a transport mechanism (not shown) is provided for transporting the workpiece 11 between the holding table 10 and the spinner table 46. After being processed by the cutting units 20a and 20b, the workpiece 11 is transported from the holding table 10 to the spinner table 46 by the transport mechanism and cleaned. After cleaning, the workpiece 11 is then loaded into the cassette 8 by the transport mechanism.

[0040] A cover 50 is provided on the upper side of the base 4 to cover the components mounted on the base 4. In Figure 1, the outline of the cover 50 is shown by a dashed line. A display unit (display unit, display device) 52 that displays information related to the cutting device 2 is provided on the side of the cover 50. In addition, a notification unit (notification unit, notification device) 54 that notifies the operator of information is provided on the upper part of the cover 50.

[0041] The display unit 52 is composed of various displays and displays information related to the processing of the workpiece 11 (processing conditions, processing status, etc.). For example, a touch panel display is used as the display unit 52. In this case, the display unit 52 also functions as an input unit (input section, input device) for inputting information to the cutting device 2, and the operator can input information to the cutting device 2 by touching the display unit 52. In other words, the display unit 52 functions as a user interface.

[0042] The notification unit 54 is, for example, an indicator light (warning light) that lights up or flashes when an abnormality occurs in the cutting device 2 to notify the operator of the error. However, there are no restrictions on the type of notification unit 54. For example, the notification unit 54 may be a speaker that notifies the operator of information by sound or voice.

[0043] Furthermore, the cutting device 2 includes a controller (control unit, control unit, control device) 56 that controls the cutting device 2. The controller 56 is connected to each component that makes up the cutting device 2 (cassette support base 6, holding table 10, moving unit 12, clamp 18, cutting units 20a, 20b, moving units 24a, 24b, imaging unit 42, cleaning unit 44, display unit 52, notification unit 54, etc.).

[0044] The controller 56 controls the operation of each component of the cutting device 2 by outputting control signals to each component. For example, the controller 56 is composed of a computer and includes a processing unit that performs calculations and other processing necessary for the operation of the cutting device 2, and a storage unit that stores various information (data, programs, etc.) used for the operation of the cutting device 2. The processing unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memory such as ROM (Read Only Memory) and RAM (Random Access Memory).

[0045] Each cutting unit 20a and 20b is equipped with an annular cutting tool (cutting blade) 58 for cutting the workpiece 11. This positions the pair of cutting tools 58 facing each other. The cutting units 20a and 20b then cut the workpiece 11, which is held by the holding table 10, by rotating the cutting tools 58 and cutting into the workpiece 11. However, the cutting device 2 may have only one set of cutting units.

[0046] Figure 2(A) is a front view showing the cutting tool 58. For example, the cutting tool 58 is an annular cutting blade (metal saw, carbide cutter) made of metal such as cemented carbide or stainless steel and does not contain abrasive grains.

[0047] If the cutting tool 58 is a metal saw made of cemented carbide, the metals included in the cemented carbide can be selected as appropriate. For example, the cutting tool 58 is made of a composite material (alloy) obtained by sintering a mixture of metal carbides such as tungsten, chromium, molybdenum, titanium, zirconium, hafnium, vanadium, niobium, and tantalum with iron-based metals (iron, cobalt, nickel, etc.). In particular, WC-Co alloys containing tungsten carbide (WC) and cobalt are suitable as a material for the cutting tool 58 because they exhibit high hardness over a wide temperature range and have excellent mechanical strength.

[0048] However, there are no restrictions on the material of the cutting tool 58. For example, the cutting tool 58 may be an annular grinding wheel formed by fixing abrasive grains made of diamond, cubic boron nitride (cBN), etc., with a binder made of metal, ceramics, resin, etc.

[0049] The cutting tool 58 has a circular opening 58a at its center that penetrates the cutting tool 58 in the thickness direction. The outer circumference of the cutting tool 58 is provided with a plurality of saw-tooth-shaped projections (protrusions, saw blades) 60 that project radially outward from the cutting tool 58. The plurality of projections 60 are formed to be generally the same shape and are arranged at generally equal intervals along the circumferential direction of the cutting tool 58.

[0050] Figure 2(B) is a front view showing a portion of the outer circumference of the cutting tool 58. The projection 60 includes a first surface (rake face) 60a and a second surface (relief face) 60b that are generally parallel to the thickness direction of the cutting tool 58. One end (tip) of the first surface 60a and one end (tip) of the second surface 60b are connected to each other, forming the tip 60c of the projection 60. The other end (base) of the first surface 60a and the other end (base) of the second surface 60b each form the bottom (cutting base) 60d of the projection 60, and are connected to the bottom 60d of other adjacent projections 60.

[0051] The inclination angle of the first surface 60a with respect to the radial direction of the cutting tool 58 is smaller than the inclination angle of the second surface 60b with respect to the radial direction of the cutting tool 58. That is, the projection 60 is formed such that the first surface 60a is steeper than the second surface 60b. For example, the first surface 60a is formed parallel to the radial direction of the cutting tool 58 (inclination angle = 0°), and the second surface 60b is formed to be inclined with respect to the radial direction of the cutting tool 58 (inclination angle ≠ 0°). Also, the distance from one end to the other of the first surface 60a is shorter than the distance from one end to the other of the second surface 60b, and the area of ​​the first surface 60a is smaller than the area of ​​the second surface 60b.

[0052] The cutting tool 58 is mounted on the cutting unit 20a (see Figure 1) and rotates in the direction indicated by arrow A (see Figure 2(A)). That is, the cutting tool 58 rotates so that the first surface 60a of each projection 60 is positioned forward in the direction of rotation of the cutting tool 58 compared to the second surface 60b. The cutting unit 20a then cuts the workpiece 11 held by the holding table 10 by causing the rotating cutting tool 58 to cut into the workpiece 11. Similarly, the cutting tool 58 is also mounted on the cutting unit 20b (see Figure 1), and the cutting unit 20b also cuts the workpiece 11 with the cutting tool 58.

[0053] When the rotating cutting tool 58 cuts into the workpiece 11, the first surface 60a of the projection 60 mainly contacts the workpiece 11 and removes material from it. The chips (cutting shavings) generated when the cutting tool 58 cuts the workpiece 11 are then sent forward in the direction of rotation of the cutting tool 58 by the first surface 60a.

[0054] Next, we will describe the configuration examples of cutting units 20a and 20b. While the following description will primarily focus on the configuration example of cutting unit 20a, cutting unit 20b can be configured in a similar manner to cutting unit 20a.

[0055] Figure 3 is an exploded perspective view showing the cutting unit 20a. The cutting unit 20a comprises a columnar housing 62 connected to the moving unit 24a (see Figure 1). The housing 62 houses a cylindrical spindle 64 arranged along the Y-axis. The tip (one end) of the spindle 64 is exposed from the housing 62, and a rotational drive source (not shown), such as a motor, is connected to the base (other end) of the spindle 64. An opening 64a is provided at the tip of the spindle 64, and a screw groove 64b is provided on the inner wall of the opening 64a.

[0056] A blade mount 66 is fixed to the tip of the spindle 64. The blade mount 66 includes a disc-shaped flange portion 68 and a cylindrical boss portion (support shaft) 70 that protrudes from the surface 68a of the flange portion 68. The blade mount 66 is also provided with an opening 66a that penetrates the center of the flange portion 68 and the boss portion 70. The blade mount 66 is fixed to the tip of the spindle 64 by inserting a fixing bolt 72 through the opening 66a of the blade mount 66 into the opening 64a of the spindle 64 and tightening it into the screw groove 64b.

[0057] On the outer surface 68a side of the flange portion 68, an annular projection 68b is provided along the outer edge of the flange portion 68, protruding from the surface 68a. The tip surface of the projection 68b is a flat surface that is generally parallel to the surface 68a and constitutes a support surface for supporting the cutting tool 58. In addition, a screw groove 70a is formed on the outer surface of the boss portion 70.

[0058] A cutting tool 58 and an annular flange (retaining flange) 74 made of metal or the like are mounted on the blade mount 66. A circular opening 74a is provided in the center of the flange 74, penetrating the flange 74 in the thickness direction. When the boss portion 70 of the blade mount 66 is inserted sequentially into the opening 58a of the cutting tool 58 and the opening 74a of the flange 74, the cutting tool 58 and the flange 74 are supported by the blade mount 66. In this state, when the annular fixing nut 76 is screwed into the thread groove 70a of the boss portion 70 and tightened, the cutting tool 58 and the flange 74 are fixed to the blade mount 66, and the cutting tool 58 is clamped between the flange portion 68 and the flange 74. As a result, the cutting tool 58 is mounted on the tip of the spindle 64 via the blade mount 66.

[0059] Furthermore, the housing 62 is fitted with a blade cover 78 that covers the cutting tool 58 attached to the tip of the spindle 64. The blade cover 78 comprises a main body 80 fixed to the tip of the housing 62 and a slide cover 82 that can slide along the X-axis to move closer to and further away from the main body 80.

[0060] The slide cover 82 is connected to the main body 80 via an air cylinder 84. The main body 80 is also provided with a connecting section 86 that is connected to an air supply passage (not shown). When air is supplied to the connecting section 86, the air cylinder 84 is driven, and the slide cover 82 slides along the X-axis so that it moves away from the main body 80. This opens the blade cover 78, allowing the cutting tool 58 to be attached to the tip of the spindle 64. After the cutting tool 58 is attached, the slide cover 82 is slid towards the main body 80 to close the blade cover 78, thereby covering the cutting tool 58 with the blade cover 78.

[0061] The main body 80 is provided with a connecting section 88 to which a liquid (cutting fluid) such as pure water is supplied, and a cutting fluid supply passage (not shown) connected to the connecting section 88. The tip of the cutting fluid supply passage opens toward the outer circumference of the cutting tool 58. When cutting fluid is supplied to the connecting section 88, the cutting fluid flows into the cutting fluid supply passage and is supplied to the outer circumference of the cutting tool 58.

[0062] The slide cover 82 is provided with a pair of connecting parts 90 to which a liquid (cutting fluid) such as pure water is supplied, and a pair of nozzles 92 connected to the pair of connecting parts 90. The pair of nozzles 92 are positioned to sandwich the lower part of the cutting tool 58 which is attached to the tip of the spindle 64. In addition, the tip of each nozzle 92 is provided with a cutting fluid supply port (not shown) that opens toward the cutting tool 58. When cutting fluid is supplied to the pair of connecting parts 90, the cutting fluid flows into the pair of nozzles 92, and the cutting fluid is sprayed from the cutting fluid supply port toward the front and back surfaces of the cutting tool 58.

[0063] The cutting tool 58, mounted on the tip of the spindle 64, rotates around a rotation axis approximately parallel to the Y-axis direction by power transmitted from a rotation drive source (not shown) via the spindle 64 and blade mount 66. The workpiece 11 (see Figure 1) is then cut by the rotating cutting tool 58 cutting into it. During the cutting of the workpiece 11, cutting fluid is supplied to both the workpiece 11 and the cutting tool 58. This cools the workpiece 11 and the cutting tool 58, and washes away the cutting chips generated by the cutting of the workpiece 11.

[0064] Furthermore, a detection unit 94 is mounted on the blade cover 78. The detection unit 94 is an optical sensor that detects the outer circumference (tip) of the cutting tool 58 mounted on the tip of the spindle 64. The detection unit 94 monitors the state of the outer circumference of the cutting tool 58 while the workpiece 11 is being cut.

[0065] Figure 4 is a front view showing the detection unit 94. The detection unit 94 includes a detection unit 100 that detects the outer periphery (tip) of the cutting tool 58. The detection unit 100 includes a rectangular parallelepiped base 100a and side wall portions 100b and 100c that protrude downward from both ends of the base 100a. The side wall portions 100b and 100c are arranged to face each other in the Y-axis direction. The space between the side wall portions 100b and 100c corresponds to the insertion portion 100d into which the outer periphery (upper end) of the cutting tool 58 is inserted.

[0066] A light emitting section 102a is provided on the inner wall portion of the side wall portion 100b (the side facing the side wall portion 100c) to emit light (detection light) 104. A light receiving section 102b is provided on the inner wall portion of the side wall portion 100c (the side facing the side wall portion 100b) to receive the light 104 emitted from the light emitting section 102a. When the cutting tool 58 is mounted on the cutting unit 20a, the outer periphery (upper end) of the cutting tool 58 is inserted into the insertion section 100d of the detection section 100, and the light emitting section 102a and the light receiving section 102b are positioned to sandwich the outer periphery of the cutting tool 58.

[0067] The light irradiation unit 102a is connected to a light source 108 that emits light 104 via an optical path 106a, such as an optical fiber, provided inside the detection unit 100. The light source 108 is composed of an LED or the like and emits light of a wavelength that is absorbed or reflected by the cutting tool 58, at least partially. On the other hand, the light receiving unit 102b is connected to a photoelectric conversion unit 110 via an optical path 106b, such as an optical fiber, provided inside the detection unit 100. The photoelectric conversion unit 110 includes a photoelectric conversion element that converts light into an electrical signal (voltage) and generates a signal (received amount signal) corresponding to the amount of light (received amount) received by the light receiving unit 102b.

[0068] Light 104 emitted from light source 108 is guided by optical path 106a to light irradiation unit 102a, and then irradiated from light irradiation unit 102a toward light receiving unit 102b. The light 104 irradiated from light irradiation unit 102a reaches the light receiving surface of light receiving unit 102b and is received by light receiving unit 102b. The light received by light receiving unit 102b is guided by optical path 106b to photoelectric conversion unit 110, and is converted into an electrical signal by photoelectric conversion unit 110. This generates a light reception amount signal corresponding to the amount of light received by light receiving unit 102b.

[0069] The light source 108 and the photoelectric conversion unit 110 are connected to the controller 56. The controller 56 outputs a control signal to the light source 108, thereby controlling the emission of light from the light source 108. In addition, the light intensity signal generated by the photoelectric conversion unit 110 is input to the controller 56.

[0070] When the light source 108 is activated with the cutting tool 58 attached to the tip of the spindle 64, light 104 is emitted from the light emitting unit 102a toward the light receiving unit 102b. At this time, a portion of the light 104 is blocked by the outer circumference of the cutting tool 58 and does not reach the light receiving unit 102b. The amount of light 104 blocked by the cutting tool 58 varies depending on the position of the tip of the cutting tool 58. Therefore, the amount of light received by the light receiving unit 102b reflects the shape of the outer circumference of the cutting tool 58, and the shape of the outer circumference of the cutting tool 58 can be determined based on the amount of light received by the light receiving unit 102b. This makes it possible to check the amount of wear on the cutting tool 58, the presence or absence of chips or cracks on the outer circumference of the cutting tool 58, etc., and to monitor the condition of the cutting tool 58.

[0071] Figure 5(A) is a side view of the cutting unit 20a, and Figure 5(B) is a side view of the cutting unit 20b. Cutting tools 58 are mounted on cutting units 20a and 20b, and a pair of cutting tools 58 are arranged to face each other (see Figure 1). In addition, detection units 94 are mounted on cutting units 20a and 20b, and the outer circumference (upper end) of the pair of cutting tools 58 is detected by the detection unit 94.

[0072] Note that when viewing the cutting tool 58 from the fixing nut 76 side, the rotation directions of the cutting tool 58 and the spindle 64 are opposite for cutting unit 20a and cutting unit 20b. For example, the cutting tool 58 mounted on cutting unit 20a rotates clockwise (in the direction indicated by arrow A in Figure 5(A)), while the cutting tool 58 mounted on cutting unit 20b rotates counterclockwise (in the direction indicated by arrow B in Figure 5(B)).

[0073] As mentioned above, the cutting tool 58 is mounted on the cutting units 20a and 20b such that the first surface 60a of the projection 60 is positioned further forward in the rotational direction of the cutting tool 58 than the second surface 60b. Therefore, as shown in Figures 5(A) and 5(B), the mounting orientation of the cutting tool 58 (the orientation of the projection 60) is reversed between the cutting unit 20a and the cutting unit 20b.

[0074] Here, when attaching the cutting tool 58 to the cutting units 20a and 20b, the operator must visually determine the orientation of the minute protrusions 60 and attach the cutting tool 58 in the predetermined orientation while considering the machining feed direction during cutting. As a result, mis-attachment of the cutting tool 58 is likely to occur. In particular, when a pair of cutting tools 58 are attached to the cutting units 20a and 20b in different orientations, the operator is more likely to misunderstand the correct orientation of the cutting tool 58, making mis-attachment of the cutting tool 58 even more likely. If cutting of the workpiece 11 continues with the cutting tool 58 attached in the wrong orientation, the workpiece 11 may not be cut as intended, potentially resulting in machining defects.

[0075] Therefore, in this embodiment, the outer circumference of the cutting tool 58 mounted on the cutting units 20a and 20b is detected by the detection unit 94, and the orientation of the cutting tool 58 is determined based on the amount of light received by the light receiving unit 102b (see Figure 4). This prevents the cutting of the workpiece 11 from continuing with the cutting tool 58 mounted in the wrong orientation.

[0076] The orientation of the cutting tool 58 is determined, for example, by the controller 56 of the cutting device 2. The following describes the determination of the orientation of the cutting tool 58 mounted on the cutting unit 20a. However, the orientation of the cutting tool 58 mounted on the cutting unit 20b can also be determined by a similar process.

[0077] Figure 6 is a block diagram of the controller 56. In addition to a block diagram showing the functional configuration of the controller 56, Figure 6 also illustrates some of the components of the cutting device 2 (display unit 52, notification unit 54, detection unit 94).

[0078] The controller 56 includes a processing unit 120 that performs the processing necessary for the operation of the cutting device 2, and a storage unit 130 that stores information (data, programs, etc.) used in the processing by the processing unit 120. The processing unit 120 also includes a determination unit 122 that determines the orientation of the cutting tool 58 attached to the cutting unit 20a, and a control unit 124 that controls the components of the cutting device 2 based on the result of the determination by the determination unit 122.

[0079] The determination unit 122 is connected to the photoelectric conversion unit 110 of the detection unit 94. When the light receiving unit 102b receives light 104 emitted from the light irradiation unit 102a, the photoelectric conversion unit 110 generates a light intensity signal corresponding to the amount of light received by the light receiving unit 102b and outputs it to the determination unit 122. The determination unit 122 then performs information processing on the light intensity signal to extract information necessary for determining the orientation of the cutting tool 58 from the light intensity signal and determines whether the cutting tool 58 is correctly mounted or incorrectly mounted. A specific example of the information processing by the determination unit 122 will be described later.

[0080] The correct mounting state corresponds to the state in which the cutting tool 58 is mounted such that the first surface 60a of the projection 60 is positioned forward of the second surface 60b in the rotational direction of the cutting tool 58 (see Figures 5(A) and 5(B)). On the other hand, the incorrect mounting state corresponds to the state in which the cutting tool 58 is mounted such that the first surface 60a of the projection 60 is positioned behind the second surface 60b in the rotational direction of the cutting tool 58.

[0081] Furthermore, the determination unit 122 outputs a signal to the control unit 124 as a determination result indicating either that the cutting tool 58 is in the correct mounting state (correct mounting signal) or that the cutting tool 58 is in the incorrect mounting state (incorrect mounting signal). The control unit 124 then controls the operation of each component of the cutting device 2 based on the determination result of the determination unit 122.

[0082] Specifically, when a correct mounting signal is input from the determination unit 122 to the control unit 124, the control unit 124 outputs control signals to each component of the cutting device 2, causing the cutting device 2 to perform cutting of the workpiece 11 with the cutting tool 58. As a result, the workpiece 11 is cut by the cutting tool 58 which is mounted in the correct orientation.

[0083] On the other hand, when the determination unit 122 inputs a mis-mounting signal to the control unit 124, the control unit 124 outputs control signals to each component of the cutting device 2, temporarily suspending the cutting of the workpiece 11 by the cutting device 2. The control unit 124 also outputs control signals to the display unit 52 and the notification unit 54, causing them to issue a warning to the operator that the cutting tool 58 is mounted in the wrong direction. For example, the control unit 124 displays a message on the display unit 52 indicating that the cutting tool 58 is mounted in the wrong direction, and also lights up or flashes the notification unit 54 (indicator light).

[0084] Next, a method for determining the orientation of a cutting tool 58, and a specific example of a workpiece machining method including the determination method will be explained with reference to Figures 6 to 9(B). In the following, as an example, we will describe in detail the case in which the determination unit 122 determines the orientation of the cutting tool 58 mounted on the cutting unit 20a based on the dimensions of the projection 60, which are determined from the amount of light received by the light receiving unit 102b.

[0085] When determining the orientation of the cutting tool 58, the detection unit 94 first detects the outer circumference of the cutting tool 58. Specifically, the cutting tool 58 is attached to the tip of the spindle 64 (see Figure 4, etc.) of the cutting unit 20a, and the outer circumference (upper end) of the cutting tool 58 is inserted into the insertion part 100d of the detection unit 100. This positions the light irradiation unit 102a and the light receiving unit 102b so as to sandwich the outer circumference of the cutting tool 58. In this state, the detection unit 94 is operated while the cutting tool 58 is rotated. As a result, light 104 is irradiated from the light irradiation unit 102a toward the light receiving unit 102b, and the light 104 is received by the light receiving unit 102b. In this way, the amount of light received by the light receiving unit 102b is measured (light received amount measurement step).

[0086] Here, the amount of light received by the light-receiving unit 102b reflects the shape of the protrusions 60 of the cutting tool 58 (see Figure 2(A), etc.). Specifically, the light 104 traveling from the light-emitting unit 102a to the light-receiving unit 102b is sequentially irradiated onto the multiple protrusions 60 of the rotating cutting tool 58. When a protrusion 60 is positioned in the path of the light 104, the light 104 is blocked by the protrusion 60, and the amount of light received by the light-receiving unit 102b decreases. Also, when a gap between adjacent protrusions 60 is positioned in the path of the light 104, the light 104 passes through the gap and reaches the light-receiving unit 102b, and the amount of light received by the light-receiving unit 102b increases. Therefore, the change in the amount of light received by the light-receiving unit 102b corresponds to the contours of the multiple protrusions 60 present on the outer circumference of the cutting tool 58.

[0087] Figure 7(A) is a graph showing the change in the amount of light received by the light receiving unit 102b when the cutting tool 58 is correctly mounted. When the cutting tool 58 is correctly mounted such that the first surface 60a of the projection 60 is positioned forward in the rotational direction of the cutting tool 58 compared to the second surface 60b (see Figure 5(A)), the amount of light received decreases sharply when light 104 is shone on the first surface 60a of the projection 60, and then gradually increases when light 104 is shone on the second surface 60b of the projection 60. As a result, as shown in Figure 7(A), a sharp decrease and a gradual increase in the amount of light received are periodically repeated.

[0088] Figure 7(B) is a graph showing the change in the amount of light received by the light receiving unit 102b when the cutting tool 58 is incorrectly mounted. When the cutting tool 58 is incorrectly mounted such that the first surface 60a of the projection 60 is positioned behind the second surface 60b in the rotational direction of the cutting tool 58, the amount of light received gradually decreases when light 104 is shone on the second surface 60b of the projection 60, and then the amount of light received increases sharply when light 104 is shone on the first surface 60a of the projection 60. As a result, as shown in Figure 7(B), a gradual decrease and a sharp increase in the amount of light received are periodically repeated.

[0089] As described above, the change in the amount of light received by the light receiving unit 102b tends to differ depending on the orientation of the cutting tool 58. The amount of light received by the light receiving unit 102b is then converted into an electrical signal by the photoelectric conversion unit 110 and sequentially input as a light received signal to the determination unit 122 (see Figure 6).

[0090] Next, the orientation of the cutting tool 58 is determined based on the amount of light received by the light receiving unit 102b measured in the above light receiving amount measurement step (determination step). In the determination step, the determination unit 122 determines the orientation of the cutting tool 58 based on the amount of light received by the light receiving unit 102b. For example, the determination unit 122 identifies the dimensions of the projection 60 based on the amount of light received by the light receiving unit 102b and determines the orientation of the cutting tool 58 based on the dimensions of the projection 60.

[0091] Specifically, the determination unit 122 first performs a conversion process to generate contour data corresponding to the contours of the multiple protrusions 60 by applying information processing to the amount of light received by the light receiving unit 102b. As described above, the protrusions 60 of the cutting tool 58 are detected as a decrease in the amount of light received by the light receiving unit 102b. Furthermore, the multiple protrusions 60 are detected sequentially from the front to the rear in the rotational direction of the cutting tool 58, and are reflected sequentially from left to right (in the direction of increasing measurement time) in the change in the amount of light received shown in Figures 7(A) and 7(B). Therefore, by reversing the sign of the measurement time (horizontal axis) and the amount of light received (vertical axis), the change in the amount of light received can be converted into contour data corresponding to the contours of the multiple protrusions 60.

[0092] Figure 8(A) is a graph showing the contour data 140a (first contour data) of the cutting tool 58 in the correctly mounted state, and Figure 8(B) is a graph showing the contour data 140b (first contour data) of the cutting tool 58 in the incorrectly mounted state. Contour data 140a is data obtained by converting the change in the amount of light received shown in Figure 7(A) into a shape corresponding to the contour of the protrusion 60, and contour data 140b is data obtained by converting the change in the amount of light received shown in Figure 7(B) into a shape corresponding to the contour of the protrusion 60. The increase or decrease in contour data 140a and 140b corresponds to the displacement of the Z coordinate of the tip (upper end) of the rotating cutting tool 58. The multiple peaks appearing in contour data 140a and 140b each correspond to the contour of the protrusion 60.

[0093] The dimensions of the multiple peaks appearing in the contour data 140a and 140b vary depending on the detection conditions of the cutting tool 58 (rotational speed of the cutting tool 58, intensity of light 104, etc.), and therefore do not necessarily perfectly match the dimensions of the actual projection 60 of the cutting tool 58. However, as long as the detection conditions are set appropriately, the shape, inclination, and other characteristics of the first surface 60a and second surface 60b of the projection 60 (see Figure 2(B), etc.) are reflected in the peaks of the contour data 140a and 140b.

[0094] The contour of the protrusion 60 can also be detected by imaging the outer circumference of the cutting tool 58 and acquiring an image of the protrusion 60. However, extracting the contour of the protrusion 60 from the image of the protrusion 60 requires complex image processing such as edge detection, which increases the processing burden. On the other hand, as described above, the change in the amount of light received by the light receiving unit 102b is numerical data that reflects the contour of the protrusion 60 of the cutting tool 58. Therefore, contour data 140a and 140b corresponding to the contour of the protrusion 60 can be obtained by simply processing the light amount data. This reduces the processing burden on the determination unit 122.

[0095] In addition, when the detection unit 94 is standardly mounted on the cutting device 2 to monitor the state of the cutting tool 58 (such as the amount of wear, the presence or absence of chipping or cracking, etc.), the light reception amount signal for detecting the orientation of the cutting tool 58 can also be acquired by the detection unit 94 without adding other sensors to the cutting device 2. Thereby, an increase in the cost and a layout change of the cutting device 2 can be avoided.

[0096] Next, the determination unit 122 executes an extreme value detection process for detecting extreme values for specifying the dimensions of the cutting tool 58. Specifically, first, the determination unit 122 sets a threshold value used for specifying the extreme value. For example, the determination unit 122 sets the minimum value Z ,

[0098] , th1 , and the maximum value Z max of the contour data 140a and 140b extracted from the light reception amount of the light reception unit 102b. Further, the determination unit 122 calculates the average value Z min between Z max and Z ave , calculates a predetermined value between Z min and Z ave as the first threshold value Z th1 , and calculates a predetermined value between Z max and Z ave as the second threshold value Z th2 respectively (see FIGS. 8(A) and 8(B)).

[0097] Next, the determination unit 122 uses the first threshold value Z th1 and the second threshold value Z th2 to specify the maximum and minimum values of the contour data 140a and 140b. For example, the determination unit 122 reads the contour data 140a and 140b in order from the left end to the right end (-X direction). At this time, the determination unit 122 reads the contour data 140a and 140b while switching between a mode for detecting the maximum value (maximum value detection mode) and a mode for detecting the minimum value (minimum value detection mode) of the contour data 140a and 140b.

[0098] Specifically, first, the determination unit 122 reads the contour data 140a and 140b in order in the -X direction in the maximum value detection mode. Then, when the contour data 140a and 140b are greater than the first threshold value Z th1When the value falls below a certain point, the system switches from maximum value detection mode to minimum value detection mode, and the determination unit 122 identifies the maximum value of the contour data 140a and 140b that were read while the system was set to maximum value detection mode. The point where this maximum value is obtained is detected as the maximum point 142. The maximum point 142 corresponds to the tip 60c of the projection 60 (see Figure 2(B)).

[0099] Next, the determination unit 122 reads the contour data 140a and 140b sequentially along the -X direction in minimum value detection mode. Then, the contour data 140a and 140b are found to be at the second threshold Z th2 When this occurs, the system switches from minimum value detection mode to maximum value detection mode, and the determination unit 122 identifies the minimum value of the contour data 140a and 140b read while the system was set to minimum value detection mode. The point where this minimum value is obtained is detected as the minimum point 144. The minimum point 144 corresponds to the bottom 60d of the projection 60 of the cutting tool 58 (see Figure 2(B)).

[0100] By repeating the above process, multiple local maximums 142 and multiple local minimums 144 contained in contour data 140a and 140b are detected. In the above, a binary threshold (Z) is used as the threshold that defines the timing for switching between the local maximum detection mode and the local minimum detection mode. th1 ,Z th2 We have explained the case where ) is used, but the threshold can also be a single value. For example, if the threshold is Z ave You can also use this.

[0101] Next, the determination unit 122 performs a dimension calculation process to calculate the dimensions of the projection 60 based on the maximum point 142 and the minimum point 144. For example, the determination unit 122 calculates a value corresponding to the distance between the tip 60c and the base 60d of the projection 60 (see Figure 2(B)).

[0102] Figure 9(A) is a graph showing contour data 140a to which dimension calculation processing is performed, and Figure 9(B) is a graph showing contour data 140b to which dimension calculation processing is performed. The determination unit 122 calculates the distance D1 in the X-axis direction between a predetermined maximum point 142 and a minimum point 144 adjacent to the right of the maximum point 142. Next, the determination unit 122 calculates the distance D2 in the X-axis direction between the minimum point 144 used to calculate distance D1 and a maximum point 142 adjacent to the right of the minimum point 144. Furthermore, the determination unit 122 calculates the distance D1 in the X-axis direction between the maximum point 142 used to calculate distance D2 and a minimum point 144 adjacent to the right of the maximum point 142.

[0103] By performing the above process for all local maximums 142 and local minimums 144, multiple distances D1 and D2 are calculated. The determination unit 122 then calculates the average value of D1 and the average value of D2. The determination unit 122 may also calculate the sum of D1 and the sum of D2. This allows the dimensions of the peaks of the contour data 140a and 140b corresponding to the projections 60 of the cutting tool 58 to be determined.

[0104] Next, the determination unit 122 performs a direction determination process to determine the orientation of the cutting tool 58 mounted on the cutting unit 20a. For example, the determination unit 122 compares the average value (or sum) of D1 with the average value (or sum) of D2 and determines the orientation of the cutting tool 58 based on the relationship between the two values.

[0105] Specifically, when the cutting tool 58 is correctly mounted on the cutting unit 20a and the first surface 60a of the projection 60 is positioned further forward in the rotational direction of the cutting tool 58 than the second surface 60b (see Figure 5(A)), contour data 140a as shown in Figure 9(A) is obtained. The average value (or sum) of D1 corresponding to the distance from the maximum point 142 to the minimum point 144 is smaller than the average value (or sum) of D2 corresponding to the distance from the minimum point 144 to the maximum point 142. In this case, the determination unit 122 determines that the cutting tool 58 is mounted in the correct orientation (correct mounting state) and outputs a correct mounting signal to the control unit 124.

[0106] On the other hand, if the cutting tool 58 is incorrectly mounted on the cutting unit 20a and the first surface 60a of the projection 60 is positioned further back in the rotational direction of the cutting tool 58 than the second surface 60b, contour data 140b as shown in Figure 9(B) is obtained. The average value (or sum) of D1 corresponding to the distance from the maximum point 142 to the minimum point 144 is greater than the average value (or sum) of D2 corresponding to the distance from the minimum point 144 to the maximum point 142. In this case, the determination unit 122 determines that the cutting tool 58 is mounted in the wrong orientation (incorrect mounting state) and outputs an incorrect mounting signal to the control unit 124.

[0107] However, the specific method for determining the mounting state of the cutting tool 58 based on D1 and D2 is not limited to the above. For example, the determination unit 122 may determine the orientation of the cutting tool 58 based on whether the values ​​of D1 and / or D2 are within a predetermined range. Specifically, the storage unit 130 of the controller 56 stores reference values ​​(upper and / or lower limits) of D1 and D2 that define the correct mounting state and the incorrect mounting state. The determination unit 122 then determines whether the cutting tool 58 is in a correct or incorrect mounting state by comparing the calculated values ​​of D1 and D2 with the reference values. The determination unit 122 can also calculate the straight-line distance from the maximum point 142 to the minimum point 144 and the straight-line distance from the minimum point 144 to the maximum point 142, and determine the orientation of the cutting tool 58 based on these immediate distances.

[0108] As described above, the determination unit 122 calculates values ​​(D1, D2) corresponding to the dimensions of the protrusion 60 identified based on the amount of light received by the light receiving unit 102b, and determines the orientation of the cutting tool 58 based on these dimensional values. The determination unit 122 then outputs a correct mounting signal or an incorrect mounting signal to the control unit 124 (see Figure 6), and the operation of each component of the cutting device 2 is controlled based on the determination result. This prevents the machining of the workpiece 11 from continuing with the cutting tool 58 mounted in the wrong orientation.

[0109] The determination unit 122 can also determine the orientation of the cutting tool 58 based on information other than the dimensions of the projection 60. For example, the determination unit 122 may determine the orientation of the cutting tool 58 based on the inclination of the projection 60, which is determined based on the amount of light received by the light receiving unit 102b. In this case, the determination unit 122 performs an inclination calculation process to calculate the inclination of the projection 60 based on the coordinates of the maximum point 142 and minimum point 144 detected by the extreme value detection process described above.

[0110] Figure 10(A) is a graph showing contour data 140a to which the inclination calculation process is performed, and Figure 10(B) is a graph showing contour data 140b to which the inclination calculation process is performed. For example, the determination unit 122 calculates values ​​corresponding to the inclination of the first surface 60a and the second surface 60b of the projection 60 (see Figure 2(B)).

[0111] Specifically, first, the determination unit 122 selects one local maximum point 142 and two local minimum points 144 adjacent to that local maximum point 142 from the contour data 140a and 140b. Then, the determination unit 122 identifies the side edge 146a from the local maximum point 142 to one of the local minimum points 144, and the side edge 146b from the local maximum point 142 to the other local minimum point 144.

[0112] Next, the determination unit 122 calculates the slope of the sides 146a and 146b. For example, the determination unit 122 calculates a straight line that approximates the sides 146a and 146b, and the slope angle θ of the approximate straight line of side 146a with respect to the Z-axis direction. a And the inclination angle θ of the approximate straight line of side 146b with respect to the Z-axis direction. b Calculate the result.

[0113] The determination unit 122 then determines the orientation of the cutting tool 58 based on the inclination of the sides 146a and 146b. Specifically, when the cutting tool 58 is in the correct mounting position, as shown in Figure 10(A), θ a θ b It becomes larger than . On the other hand, if the cutting tool 58 is incorrectly installed, as shown in Figure 10(B), θ a θ bIt becomes smaller than that. Therefore, the determination unit 122 can determine whether the cutting tool 58 is correctly mounted by comparing the magnitude of the inclination of the sides 146a and 146b. In this way, the orientation of the cutting tool 58 may be determined based on the inclination of the sides 146a and 146b of the peaks appearing in the contour data 140a and 140b.

[0114] The determination made by the determination unit 122 is achieved when the controller 56 (see Figure 6) executes a program stored in the storage unit 130. Specifically, the storage unit 130 stores a program that describes each of the processes performed by the determination unit 122. The controller 56 then reads and executes the program, so that each process performed by the determination unit 122 is executed sequentially, and the orientation of the cutting tool 58 is automatically determined.

[0115] The above determination step determines whether the orientation of the cutting tool 58 is correct or not. If the determination step determines that the orientation of the cutting tool 58 is incorrect (incorrectly mounted), the display unit 52 and / or notification unit 54 notify the operator of the error. For example, the display unit 52 displays a message indicating that the cutting tool 58 is mounted in the wrong orientation, and the notification unit 54 (indicator light) lights up or flashes.

[0116] On the other hand, if the cutting tool 58 is determined to be in the correct orientation (correctly mounted state) in the determination step, the workpiece 11 is cut by the cutting tool 58 (cutting step). For example, in the cutting step, the workpiece 11 is cut along streets set in a grid pattern on the workpiece 11, thereby dividing the workpiece 11 into multiple chips.

[0117] Specifically, first, the workpiece 11 is held via the sheet 15 by the holding table 10 shown in Figure 1. Next, the holding table 10 is rotated to align the length of a predetermined street with the X-axis direction (machining feed direction). The position of the cutting unit 20a in the Y-axis direction is also adjusted so that the cutting tool 58 is positioned on the extension of the predetermined street. Furthermore, the height of the cutting unit 20a is adjusted so that the lower end of the cutting tool 58 is positioned below the back surface of the workpiece 11 (the upper surface of the sheet 15) and above the holding surface 10a (the lower surface of the sheet 15).

[0118] Next, with the cutting tool 58 rotating, the holding table 10 is moved along the X-axis. This causes the holding table 10 and the cutting tool 58 to move relative to each other along the X-axis (machining feed). At this time, the cutting tool 58, which is mounted in the correct orientation on the cutting unit 20a, rotates so that the first surface 60a of each projection 60 is positioned further forward in the rotational direction of the cutting tool 58 than the second surface 60b (see Figure 5(A)).

[0119] As described above, when the machining feed is performed, the cutting tool 58 cuts the workpiece 11 along the streets. As a result, machining marks (kerfs) are formed along the streets from the front to the back surface of the workpiece 11, and the workpiece 11 is divided along the streets. Thereafter, the same procedure is repeated to cut the workpiece 11 along all the streets. As a result, the workpiece 11 is divided into multiple chips and fragmented. In other words, the workpiece machining method according to this embodiment corresponds to a chip manufacturing method.

[0120] However, there are no restrictions on the type of cutting performed on the workpiece 11 during the cutting step. For example, by inserting the cutting tool 58 into the surface of the workpiece 11 with a cutting depth less than the thickness of the workpiece 11, a groove (cutting groove) with a depth less than the thickness of the workpiece 11 may be formed on the surface of the workpiece 11.

[0121] As described above, the cutting apparatus according to this embodiment includes a detection unit 94 in which a light irradiation unit 102a and a light receiving unit 102b are arranged to sandwich the outer circumference of the cutting tool 58, and the orientation of the cutting tool 58 is determined based on the amount of light received by the light receiving unit 102b. This prevents the cutting of the workpiece 11 from continuing with the cutting tool 58 mounted in the wrong orientation, and prevents the occurrence of machining defects due to incorrect mounting of the cutting tool 58.

[0122] The configuration of the cutting apparatus 2 according to this embodiment can be appropriately modified within a range that allows for the determination of the orientation of the cutting tool 58. For example, instead of attaching the detection unit 94 to the blade cover 78 (see Figure 3) of the cutting units 20a and 20b, another detection unit having the same function as the detection unit 94 may be attached to a component other than the cutting units 20a and 20b.

[0123] For example, a detection unit comprising a light irradiating unit and a light receiving unit may be installed on the holding table 10 or table cover 14 shown in Figure 1. In this case, the detection unit can be positioned along the X-axis direction by the moving unit 12. When determining the orientation of the cutting tool 58, the positional relationship between the cutting tool 58 and the detection unit is adjusted by the moving unit 12 and moving units 24a and 24b, so that the outer circumference (lower end) of the cutting tool 58 is positioned between the light irradiating unit and the light receiving unit. The orientation of the cutting tool 58 is then determined by the same procedure as when using the detection unit 94.

[0124] Furthermore, the processing performed by the controller 56 can be appropriately modified within the range that allows for the determination of the orientation of the cutting tool 58. For example, in the above embodiment, an example was described in which the light-receiving data (see Figures 7(A) and 7(B)) is converted into contour data (see Figures 8(A) and 8(B)), and the orientation of the cutting tool 58 is determined based on the contour data. However, since the shape of the protrusion 60 of the cutting tool 58 is already reflected in the light-receiving data, the orientation of the cutting tool 58 can also be determined by directly applying a series of processes corresponding to the aforementioned extreme value detection process, dimension calculation process (or inclination calculation process), and orientation identification process to the light-receiving data.

[0125] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the objectives of the present invention. [Explanation of Symbols]

[0126] 11 Workpiece 13 frames 15 sheets 2 Cutting equipment 4 base 4a,4b,4c opening 6 Cassette Support Stands 8 cassettes 10. Holding table (chuck table) 10a Holding surface 12 Mobile Units 14 Table Covers 16 Dustproof and splashproof cover 18 clamps 20a, 20b Cutting Unit 22 Support structure 24a, 24b Mobile Unit 26 Y-axis guide rail 28a, 28b Y-axis moving plate 30a, 30b Y-axis ball screw 32 Y-axis pulse motor 34a, 34b Z-axis guide rail 36a, 36b Z-axis moving plate 38a, 38b Z-axis ball screw 40a, 40b Z-axis pulse motor 42 Imaging Units 44 Washing Unit 46 Spinner Table 46a Holding surface 48 nozzles 50 Covers 52 Display unit (display unit, display device) 54. Notification Unit (Notification Section, Notification Device) 56 Controller (control unit, control unit, control device) 58 Cutting Tools (Cutting Blades) 58a aperture 60. Protrusions (convex parts, saw blades) 60a First surface (scoop surface) 60b Second face (escape face) 60c tip 60d bottom (bottom of blade) 62 Housing 64 spindles 64a aperture 64b Screw groove 66 Blade Mount 66a aperture 68 Flange section 68a surface 68b Convex part 70 Boss section (support shaft) 70a thread groove 72 Fixing bolts 74 Flange (Retaining flange) 74a aperture 76 Fixing nut 78 Blade Cover 80 Main body 82 Slide Cover 84 Air Cylinder 86,88,90 Connection part 92 nozzles 94 detection units 100 Detection unit 100a Base 100b,100c side wall part 100d Insertion section 102a Light irradiation part 102b Light receiving section 104 Light (detection light) 106a,106b Optical path 108 Light source 110 Photoelectric conversion unit 120 Processing Unit 122 Judgment section 124 Control Unit 130 Storage section 140a, 140b contour data 142 Maximum point 144 Minimum point 146a,146b side

Claims

1. A cutting device for cutting a workpiece, A holding table for holding the workpiece, A cutting unit having a spindle on which a cutting tool for cutting the workpiece held in the holding table is attached to the tip, A detection unit having a light irradiation unit and a light receiving unit, which are positioned to sandwich the outer circumference of the cutting tool mounted on the cutting unit, Equipped with a controller, The outer circumference of the cutting tool is provided with a plurality of protrusions, including a first surface for sending out cutting chips generated when the cutting tool cuts the workpiece, and a second surface connected to the first surface. The light irradiation unit irradiates light toward the outer circumference of the cutting tool, The light receiving unit receives light emitted from the light irradiating unit, The controller is a cutting device that determines the orientation of the cutting tool attached to the cutting tool based on the amount of light received by the light receiving unit.

2. The cutting apparatus according to claim 1, wherein the controller determines the orientation of the cutting tool based on the dimensions of the protrusion, which are determined from the amount of light received by the light receiving unit.

3. A method of machining a workpiece by cutting the workpiece with a cutting tool, The outer circumference of the cutting tool is provided with a plurality of protrusions, including a first surface for sending out cutting chips generated when the cutting tool cuts the workpiece, and a second surface connected to the first surface. With the cutting tool mounted on the tip of the spindle and the light-emitting unit and light-receiving unit positioned so as to sandwich the outer circumference of the cutting tool, the cutting tool is rotated while light is irradiated from the light-emitting unit toward the light-receiving unit, and the amount of light received by the light-receiving unit is measured in the light-receiving amount measurement step. A determination step in which the orientation of the cutting tool is determined based on the amount of light received by the light receiving unit measured in the light receiving amount measurement step, A method for machining a workpiece, comprising: a cutting step in which, after it is determined in the determination step that the orientation of the cutting tool is correct, the cutting tool is rotated in a direction such that the first surface is positioned forward in the rotational direction compared to the second surface, and the cutting tool is used to cut the workpiece.

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