Cutting edge position detection method for cutting blade

Abstract

To provide a new method for accurately inspecting a cutting edge position of a cutting blade.SOLUTION: A cutting edge position detection method of a cutting blade 32 mounted on a spindle tip includes the steps of: holding an inspection piece P on an inspection table 60; positioning the cutting blade 32 at a predetermined depth from an upper surface PS of the inspection piece P and relatively moving the cutting blade 32 and the inspection table 60 to flatten the inspection piece P; forming a cut groove G in the inspection piece P with the cutting blade 32 by positioning the cutting blade 32 at a height at which a desired cutting depth is obtained with respect to the inspection piece P when the cutting edge position of the cutting blade 32 stored in advance after the flattening step is used as a reference and relatively moving the cutting blade 32 and the inspection table 60; measuring the depth of the cut groove G; and calculating a difference between the depth of the cut groove G and a desired cutting depth as a correction value and correcting the cutting edge position of the cutting blade 32.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for detecting the cutting edge position of a cutting blade.

Background Art

[0002] A cutting device that forms a cutting groove in a workpiece with a cutting blade manages the cutting edge position of the cutting blade in order to precisely control the depth of the cutting groove (also referred to as the cutting depth). However, since the cutting edge of the cutting blade wears due to cutting and the outer diameter of the cutting blade changes, an error may occur between the cutting edge position managed by the cutting device and the actual cutting edge position. If cutting is performed with an error in the cutting edge position, a situation may occur where a cutting groove with a desired depth is not formed.

[0003] Techniques related to such problems are described in, for example, Patent Document 1. Patent Document 1 describes a technique of cutting an inspection piece and observing the cutting groove thereof.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described in Patent Document 1, by actually cutting an inspection piece and observing the grinding groove, it is possible to detect the error between the cutting depth and the desired depth. And if the error factor between the cutting depth and the desired depth is only the change in the outer diameter of the cutting blade due to wear or the like, it is possible to form a cutting groove with a desired depth by correcting the cutting edge position by the detected error amount.

[0006] However, in the above-described inspection, there are other error factors, and when the error caused by the error factor can change with each inspection, it is difficult to accurately form a cutting groove with a desired depth even if the cutting edge position is corrected with the correction value (corresponding to the error) obtained by cutting the inspection piece.

[0007] The present invention has been made in view of such points, and an object thereof is to provide a new method for accurately inspecting the cutting edge position of a cutting blade.

Means for Solving the Problems

[0008] A method for detecting the cutting edge position of a cutting blade according to one aspect of the present invention is a method for detecting the cutting edge position of a cutting blade mounted on the tip of a spindle, comprising: a holding step of holding an inspection piece on an inspection table; a flattening step of positioning the cutting blade at a predetermined depth from the upper surface of the inspection piece and relatively moving the cutting blade and the holding table to flatten the inspection piece; after the flattening step, positioning the cutting blade at a height that results in a desired cutting depth with respect to the inspection piece based on the cutting edge position of the cutting blade stored in advance, and relatively moving the cutting blade and the inspection table to form a cutting groove in the inspection piece with the cutting blade; a cutting depth measurement step of measuring the depth of the cutting groove; and a correction step of calculating the difference between the depth of the cutting groove and the desired cutting depth as a correction value and correcting the cutting edge position of the cutting blade.

Advantages of the Invention

[0009] According to the present invention, it is possible to provide a new method for accurately inspecting the cutting edge position of a cutting blade.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0011] Hereinafter, a cutting device according to an embodiment will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of a cutting device 10 according to an embodiment. The cutting device 10 shown in FIG. 1 is a device that performs cutting on a workpiece 11 using a cutting unit 30, and forms a cutting groove by cutting. The X-axis direction and Y-axis direction in the cutting device 10 are horizontal directions, and the X-axis direction and Y-axis direction are perpendicular to each other. The Z-axis direction is the vertical direction, with the +Z direction being upward and the -Z direction being downward.

[0012] The cutting device 10 has a control unit 100. The control unit 100 controls each part of the cutting device 10 described below to cause the cutting device 10 to perform machining operations, inspections, etc. The control unit 100 is a computer having an arithmetic processing unit such as a CPU (Central Processing Unit), a storage device such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and an input / output interface connected to each part of the cutting device 10. The arithmetic processing unit of the control unit 100 performs arithmetic processing according to a program stored in the storage device, and outputs a control signal for controlling the cutting device 10 to each part of the cutting device 10 via the input / output interface. Further, signals detected by each part of the cutting device 10 are input to the control unit 100 via the input / output interface.

[0013] The cutting device 10 includes a notification unit 80 that notifies an operator. The notification unit 80 is composed of a display monitor, display lamp, speaker, etc. provided in the cutting device 10, and performs notification by displaying information on the display monitor, lighting or flashing the display lamp, and emitting sound from the speaker. Note that the cutting device 10 includes a communication unit that enables communication with external devices (such as servers, personal computers, and tablet terminals), and it is also possible to transmit information from the communication unit of the cutting device 10 to an external device and use the communication unit or the external device as the notification unit.

[0014] The workpiece 11 is a plate-shaped object to be processed that can form cutting grooves by cutting with the cutting device 10. For example, the workpiece 11 is a disk-shaped wafer made of a material such as silicon, sapphire, or gallium. On the surface of the workpiece 11, chips 12, which are electronic devices, are formed in regions partitioned in a grid pattern by a plurality of division planned lines formed in a grid pattern.

[0015] Note that the type, material, and shape of the workpiece are not limited to the workpiece 11 of the present embodiment. For example, the workpiece may be a rectangular package substrate. Further, the workpiece is not limited to a wafer or a package substrate on which an electronic device is formed, and may be a material wafer before forming the device, or other substrates or plate materials.

[0016] Further, unlike the workpiece 11 of the present embodiment, the cutting groove formed in the workpiece may be other than the groove along the planned dividing line for dividing the chip. Also, the cutting groove may be a full cut groove that penetrates the workpiece, or a bottomed half cut groove formed to the middle of the thickness of the workpiece.

[0017] The workpiece 11 is held inside the opening of the annular frame 13 via the support tape 14. The support tape 14 has a larger area than the workpiece 11, and the adhesive surface of the support tape 14 is adhered to the back surface of the workpiece 11 and the back surface of the annular frame 13. In the cutting device 10, processing and conveyance are performed in the state of the workpiece unit 15 composed of the workpiece 11, the annular frame 13, and the support tape 14.

[0018] The workpiece unit 15 before processing the workpiece 11 is housed in a cassette (not shown) and carried into the cutting device 10. A plurality of workpiece units 15 can be housed inside the cassette. The cassette carried into the cutting device 10 is placed on the cassette placement portion 21 on the base 20.

[0019] The cutting device 10 includes a processing table 22 that holds the workpiece unit 15 when processing the workpiece 11. The processing table 22 has a disk shape, and the processing holding surface 23 for holding the workpiece 11 is formed of a porous material such as porous ceramics. A suction source (not shown) is connected to the processing holding surface 23 of the processing table 22, and by applying the suction force of the suction source to the processing holding surface 23, the workpiece 11 placed on the processing holding surface 23 is sucked and held. More specifically, the processing table 22 sucks the support tape 14 adhered to the back surface side of the workpiece 11 and holds the workpiece 11 via the support tape 14.

[0020] The machining table 22 is provided with a plurality of clamp portions (not shown) around the machining holding surface 23. The machining table 22 may be provided with, for example, four clamp portions at equal intervals in the circumferential direction of the machining holding surface 23. The workpiece 11 is sucked and held by the machining holding surface 23, and the workpiece unit 15 is fixedly held with respect to the machining table 22 by each clamp portion clamping the annular frame 13 from above and below. Each clamp portion is operable between a state of clamping the annular frame 13 from above and below and a state of releasing the clamping of the annular frame 13.

[0021] Note that in the cutting device 10, it is also possible to perform machining and conveyance in a state of only the workpiece 11 without using the annular frame 13. In this case, the machining table 22 may not be provided with a clamp portion.

[0022] The machining table 22 is moved in the X-axis direction by the X-axis movement unit 25. The X-axis movement unit 25 is constituted by a guide rail (not shown) extending in the X-axis direction and supporting the machining table 22 movably, a ball screw (not shown) rotationally driven by a motor and transmitting a moving force in the X-axis direction to the machining table 22, and the like. The machining table 22 moved in the X-axis direction by the X-axis movement unit 25 is positioned in a machining area below the cutting unit 30 and a loading / unloading area adjacent to the cassette mounting portion 21 on the +Y direction side.

[0023] Further, the machining table 22 is supported by a rotational drive unit 26 so as to be rotatable about an axis in the Z-axis direction.

[0024] A table cover 27 that moves in the X-axis direction together with the machining table 22 is provided on the base 20. The upper part of the machining table 22 including the machining holding surface 23 is exposed above the table cover 27.

[0025] The cutting device 10 includes a pair of cutting units 30 arranged to face each other in the Y-axis direction. Each cutting unit 30 is configured such that a cutting blade 32 is attached to the tip of a spindle 31 extending in the Y-axis direction, and the spindle 31 is rotationally driven by a spindle motor (not shown). The spindle 31 and the spindle motor are housed inside a spindle housing 33.

[0026] The cutting blade 32 is an annular cutting edge centered on the rotation axis of the spindle 31. The cutting blade 32 is formed by bonding abrasive grains such as diamond or CBN (Cubic Boron Nitride) with a bonding material (bonding agent) such as metal or resin. The cutting blade 32 may be a hub blade in which the cutting edge is supported by a base, or a hubless blade composed only of the cutting edge. In either form of the hub blade or the hubless blade, the cutting blade 32 is fixed to the mount on the tip side of the spindle 31, and the cutting blade 32 is rotationally driven together with the spindle 31.

[0027] Each of the pair of cutting units 30 is moved (index feed) in the Y-axis direction by a Y-axis movement unit 34 and moved (cutting feed) in the Z-axis direction by a Z-axis movement unit 35. That is, corresponding to the pair of cutting units 30, a pair of Y-axis movement units 34 and a pair of Z-axis movement units 35 are provided. Each cutting unit 30 can position the cutting blade 32 at an arbitrary position above the machining holding surface 23 by the Y-axis movement unit 34 and the Z-axis movement unit 35, and cut the cutting blade 32 into the workpiece 11 on the machining holding surface 23.

[0028] The Y-axis movement unit 34 is composed of a guide rail 37 that extends in the Y-axis direction and supports the Y-axis movement table 36 so as to be movable in the Y-axis direction, a ball screw 38 that is rotationally driven by a motor and transmits a movement force in the X-axis direction to the Y-axis movement table 36, and the like. The components of the Y-axis movement unit 34 are supported by a gantry column 39 erected on the base 20.

[0029] The Z-axis moving unit 35 includes a guide rail 41 that extends in the Z-axis direction and supports the Z-axis moving table 40 so as to be movable in the Z-axis direction, a ball screw 42 that is rotationally driven by a motor and transmits a moving force in the X-axis direction to the Z-axis moving table 40, and the like. The components of the Z-axis moving unit 35 are supported by the Y-axis moving table 36.

[0030] The spindle housing 33 of the cutting unit 30 is attached to the lower end of the Z-axis moving table 40. When the Y-axis moving unit 34 moves the Y-axis moving table 36 in the Y-axis direction, the position of the cutting unit 30 changes in the Y-axis direction. When the Z-axis moving unit 35 moves the Z-axis moving table 40 in the Z-axis direction, the position of the cutting unit 30 changes in the Z-axis direction.

[0031] On the base 20, a cleaning unit 45 is provided at a position adjacent to the +Y direction of the loading / unloading area of the processing table 22. The cleaning unit 45 includes a spinner table 46 that holds the workpiece unit 15 and is rotatable, and a cleaning nozzle (not shown) that injects cleaning liquid or drying air toward the workpiece unit 15 on the spinner table 46.

[0032] The outline of the machining operation by the cutting device 10 configured as described above will be described. The following machining operations are performed under the control of the control unit 100.

[0033] A cassette containing the workpiece unit 15 is placed on the cassette placement unit 21. The workpiece unit 15 is pulled out from the cassette by a transport mechanism (not shown) and placed on the processing table 22 located in the loading / unloading area. The workpiece 11 is sucked and held on the machining holding surface 23, and the annular frame 13 is clamped by the clamping unit, so that the workpiece unit 15 is fixedly held on the processing table 22. In this state, the X-axis moving unit 25 moves the processing table 22 to the machining area on the -X direction side.

[0034] The control unit 100 adjusts the relative positions of the machining table 22 and each cutting unit 30 in the X-axis direction and the Y-axis direction by the X-axis moving unit 25 and the Y-axis moving unit 34, and positions the cutting blade 32 of each cutting unit 30 above the end of the planned division line of the workpiece 11 to be cut.

[0035] Subsequently, while rotationally driving the spindle 31, the control unit 100 lowers each cutting unit 30 by the Z-axis moving unit 35. The cutting blade 32 of each cutting unit 30 cuts into the workpiece 11 of the workpiece unit 15 held on the machining table 22 while rotating. Then, by moving the machining table 22 in the X-axis direction (machining feed) by the X-axis moving unit 25, cutting by the cutting blade 32 is performed along the planned division line extending in the X-axis direction.

[0036] When the cutting along a set of planned division lines by each cutting unit 30 is completed, the control unit 100 raises each cutting unit 30 by the Z-axis moving unit 35 to separate the cutting blade 32 from the workpiece 11. Subsequently, the control unit 100 moves each cutting unit 30 in the Y-axis direction (indexing feed) by the Y-axis moving unit 34, and positions the cutting blade 32 of each cutting unit 30 above the end of the next uncut planned division line. Then, in the same manner as above, each cutting unit 30 is lowered (cutting feed) by the Z-axis moving unit 35, the machining table 22 is moved in the X-axis direction (machining feed) by the X-axis moving unit 25, and cutting along the planned division line is performed.

[0037] When the cutting along all the planned division lines arranged in the Y-axis direction is completed, the control unit 100 rotates the machining table 22 by 90 degrees by the rotational drive unit 26. As a result, the workpiece 11 on the machining table 22 is in a state where a plurality of uncut planned division lines are arranged in the Y-axis direction (extending in the X-axis direction). Then, in the same manner as above, each cutting unit 30 sequentially performs cutting along all the uncut planned division lines.

[0038] Note that only one of the two cutting units 30 may be operated to perform cutting on each of the division planned lines. Further, unlike the configuration shown in FIG. 1, the cutting device 10 may be configured to include only one cutting unit 30 and always perform cutting on each of the division planned lines.

[0039] When the cutting of the workpiece 11 is completed, the processing table 22 is moved from the processing area to the loading / unloading area (+X direction) by the X-axis moving unit 25. Using a transport mechanism (not shown), the workpiece unit 15 is transported from the processing table 22 that has moved to the loading / unloading area to the cleaning unit 45.

[0040] In the cleaning unit 45, a cleaning liquid is sprayed from the cleaning nozzles, and the spinner table 46 is rotated to clean the workpiece unit 15. Also, air is sprayed from the cleaning nozzles to dry the workpiece unit 15 after cleaning. The workpiece unit 15 after cleaning is transported to the position of the cassette using a transport mechanism (not shown) and stored in the cassette.

[0041] An imaging unit 50 is provided near one (+Y direction side) of the cutting units 30. The imaging unit 50 is supported by the Z-axis moving table 40 and moves integrally with one of the cutting units 30. That is, the imaging unit 50 moves in the Y-axis direction by the Y-axis moving unit 34 and moves in the Z-axis direction by the Z-axis moving unit 35.

[0042] The imaging unit 50 includes an imaging optical system and an imaging element, and can image a predetermined range below the cutting unit 30. The image signal captured by the imaging unit 50 is sent to the control unit 100. The control unit 100 processes the image signal sent from the imaging unit 50 to generate image data. The control unit 100 controls the operation of the cutting device 10 by referring to the image information in the image data.

[0043] For example, when machining the workpiece 11, the imaging unit 50 is used to image the workpiece 11 on the machining table 22, and based on a predetermined pattern on the workpiece 11, the control unit 100 adjusts the relative positional relationship between the workpiece 11 and the cutting unit 30 to set the cutting position on the planned division line by the cutting blade 32.

[0044] In addition, the control unit 100 can image the workpiece 11 after cutting using the imaging unit 50 to obtain information on the cutting grooves formed in the workpiece 11. Specifically, the workpiece 11 may be imaged by the imaging unit 50 to obtain information such as the depth of the cutting grooves.

[0045] The cutting device 10 includes an inspection table 60 separately from the machining table 22. The inspection table 60 is an example of a holding table that holds inspection pieces. The inspection pieces are used to implement a cutting edge position detection method for inspecting whether there is an error between the cutting edge position of the cutting blade 32 managed by the cutting device 10 and the actual cutting edge position of the cutting blade 32, and correcting the cutting edge position if there is an error. Details of the cutting edge position detection method will be described later. Note that, for example, silicon, synthetic resin, carbon, etc. can be applied as the material of the inspection pieces.

[0046] The inspection table 60 is provided on the table cover 27 and is arranged side by side with the machining table 22 in the X-axis direction. The workpiece 11 held on the machining holding surface 23 of the machining table 22 and the inspection pieces held on the holding surface 65 of the inspection table 60 may be installed within the range that can be machined by the cutting unit 30.

[0047] Note that the cutting device 10 may further include a dressing table that holds a dresser board between the inspection table 60 and the machining table 22. The dresser board is used for the purpose of cutting into the cutting blade 32 to eliminate clogging and uneven wear when the cutting blade 32 is clogged or unevenly worn.

[0048] <First Embodiment> The following will explain in detail the cutting-edge position detection method according to the present embodiment performed by the cutting device 10. FIG. 2 is a diagram for explaining a conventional cutting-edge position detection method of a cutting blade. In order to facilitate the understanding of the features of the cutting-edge position detection method according to the present embodiment, first, the conventional cutting-edge position detection method and its problems will be explained with reference to FIG. 2. Hereinafter, the case where the conventional cutting-edge position detection method is performed by the cutting device 10 will be described as an example.

[0049] In the conventional cutting-edge position detection method, first, as shown in FIG. 2(a), the control unit 100 lowers the cutting blade 32 mounted on the tip of the spindle 31 above the inspection table 60 and detects the height when the cutting blade 32 contacts the holding surface 65 of the inspection table 60 (holding surface height detection step). The detection of the contact between the cutting blade 32 and the holding surface 65 is performed by detecting the conduction generated by the contact. Note that the holding surface height detection step may be performed non-contact by any height measuring device such as an imaging unit or an optical sensor.

[0050] After that, when the inspection piece P is held on the holding surface 65 as shown in FIG. 2(b), the control unit 100 detects the height 71 of the upper surface PS of the inspection piece P held on the holding surface 65 with the height detector 70 as shown in FIG. 2(c) (detected piece upper surface height detection step).

[0051] Any height detector can be used for the height detector 70. The height detector 70 may be a contact type height detector such as a capacitance type touch sensor, for example, or a non-contact type height detector such as a differential pressure sensor, a laser sensor, or a microscope. Also, similar to the holding surface height detection step, the height 71 of the upper surface PS may be detected using the cutting blade 32 as the height detector 70. Note that in the holding surface height detection step as well, the height of the holding surface 65 may be detected using any of these height detectors.

[0052] When the height of the upper surface of the PS is detected, as shown in Fig. 2(d), the control unit 100 performs cutting on the test piece P with the cutting unit 30 (cutting blade 32) so that a cutting groove with a preset predetermined cutting depth is formed (cutting groove forming step).

[0053] In the cutting groove forming step, while rotating the spindle 31, the control unit 100 positions the cutting blade 32 at a height such that the desired cutting depth (the above-mentioned predetermined cutting depth, for example, 0.5 mm) is achieved with respect to the test piece P based on the cutting edge position managed by the control unit 100, that is, the cutting edge position of the cutting blade 32 stored in advance. Further, the control unit 100 relatively moves the cutting blade 32 and the inspection table 60 and feeds them in the machining direction in the X-axis direction. As a result, as shown in Fig. 2(e), a cutting groove G is formed in the test piece P by the cutting blade 32.

[0054] Thereafter, the control unit 100 measures the depth of the cutting groove G (cutting depth measurement step). The depth of the cutting groove G may be measured using the above-mentioned height detector 70. That is, in the cutting depth measurement step, the height 72 of the edge of the cutting groove G and the height 73 of the bottom may be measured respectively, and the difference therebetween may be measured as the depth of the cutting groove G. Note that the depth of the cutting groove G may be measured by measuring the height 72 of the edge and the height 73 of the bottom of the cutting groove G from a direction orthogonal to the upper surface of the test piece P. Alternatively, the depth of the cutting groove G may be measured by imaging the cross-sectional shape of the cutting groove G from the side direction of the test piece P and measuring the depth of the cutting groove G from the height 72 of the edge and the height 73 of the bottom of the cutting groove G.

[0055] Finally, the control unit 100 compares the depth measured in the cutting depth measurement step with the predetermined cutting depth (0.5 mm in this example). Then, the difference (error) between the measured depth and the predetermined cutting depth is calculated as a correction value, and the cutting edge position of the cutting blade 32 is corrected with the correction value (correction step). That is, the cutting edge position managed by the cutting device 10 is corrected by the correction value, and the corrected cutting edge position is managed by the cutting device 10 as the cutting edge position of the cutting blade 32.

[0056] In the above-described conventional cutting edge position detection method, the height of the upper surface PS of the inspection piece P is measured before and after cutting. More specifically, before cutting, the height 71 of the upper surface PS is measured as the reference height for cutting, and after cutting, the height 72 of the upper surface PS is measured as the reference height for depth measurement. When these measurement results match, it is possible to compensate for the error between the cutting edge position managed by correcting the cutting edge position described above and the actual cutting edge position.

[0057] However, if there are irregularities on the upper surface PS of the inspection piece P, the height (measurement result) of the upper surface PS may vary in the measurements before and after cutting. For example, if the height of the convex portion of the upper surface PS with irregularities before cutting is measured as the height 71 of the upper surface PS, and a cutting groove G is formed in that convex portion, the convex portion will be shaved off, so the height (height 72) of the edge of the cutting groove G measured after cutting will be lower than the height (height 71) of the convex portion measured before cutting. Similarly, if the height of the concave portion of the upper surface PS with irregularities before cutting is measured as the height of the upper surface PS, the height of the edge of the cutting groove G measured after cutting will be higher than the height of the concave portion measured before cutting.

[0058] When the height of the upper surface PS measured before and after cutting is different, even if the cutting edge position is corrected with the correction value calculated in the correction step, the cutting device 10 is not adjusted to cut at a predetermined cutting depth. This is because the value obtained by adding the difference in the height of the upper surface PS measured before and after cutting to the difference between the cutting edge position managed by the cutting device 10 and the actual cutting edge position is calculated as the correction value. As a result, the correction is not performed so that the managed cutting edge position and the actual cutting edge position match, and an error in the cutting edge position remains by the amount of the difference in the height of the upper surface PS measured before and after cutting. It is also possible to obtain the depth of the cutting groove G from the difference between the value of the upper surface height measured in the upper surface height measurement step and the height of the bottom of the cutting groove G without using the height of the edge of the cutting groove G as a reference. However, in that case, the upper surface height measurement step must be performed every time before the cutting groove formation step, resulting in a decrease in productivity. Also, when the test piece P is removed from the inspection table 60 (holding table) and the depth of the cutting groove G is measured with another device such as a microscope, the value of the upper surface height measured in the upper surface height measurement step cannot be used. Therefore, it is necessary to measure the depth of the cutting groove G from the difference between the edge and the bottom surface of the cutting groove G, and there is a possibility that an error will occur in the calculated depth of the cutting groove G if there are irregularities on the upper surface PS of the test piece P.

[0059] The cutting edge position detection method according to the present embodiment solves the problems that occur in the above-described conventional cutting edge position detection methods. FIG. 3 is a diagram for explaining the cutting edge position detection method of the cutting blade according to the present embodiment. FIG. 4 is a flowchart showing the procedure of the cutting edge position detection method of the cutting blade according to the present embodiment. FIGS. 5 to 7 are cross-sectional views showing the processing table and the inspection table of the cutting device in the flattening step, the cutting groove formation step, and the cutting groove measurement step, respectively. FIG. 8 is a diagram showing an example of an image captured in the cutting groove measurement step. Hereinafter, the cutting edge position detection method according to the present embodiment will be described with reference to FIGS. 3 to 8.

[0060] First, as shown in FIG. 3(a), the control unit 100 lowers the cutting blade 32 above the inspection table 60 and detects the height when the cutting blade 32 contacts the holding surface 65 of the inspection table 60 (holding surface height detection step S1). The holding surface height detection step S1 is the same as the conventional cutting edge position detection method.

[0061] Thereafter, as shown in FIG. 3(b), the control unit 100 holds the test piece P on the holding surface 65 (holding step S2 in FIG. 4). In the holding step S2, the control unit 100 operates a suction source (not shown for example), causing the cutting device 10 to generate a suction force on the holding surface 65 to hold the test piece P on the holding surface 65.

[0062] Next, as shown in FIG. 3(c), the control unit 100 positions the cutting blade 32 at a predetermined depth from the upper surface PS of the test piece P and relatively moves the cutting blade 32 and the inspection table 60 to flatten the test piece P (flattening step S3 in FIG. 4). In order to determine the depth of the cut into the test piece P in the cutting groove formation step S5 described later, between the holding step S2 and the flattening step S3, the height of the upper surface PS of the test piece P may be measured with an arbitrary non-contact or contact type height measuring instrument to measure the thickness of the test piece P. Or if the thickness of the test piece P is known in advance, the cut depth may be set using that value, so it is not necessary to measure the thickness of the test piece P.

[0063] As shown in FIG. 5, the inspection table 60 has a pedestal 61, a rotation shaft 62, a rotation drive unit 63, a rotation holding unit 64, and a holding surface 65. The rotation holding unit 64 is rotatably supported around the rotation shaft 62 with respect to the pedestal 61 provided on the table cover 27. The holding surface 65 is a surface for holding the inspection piece P, and is a rectangular flat surface provided on the rotation holding unit 64. By operating a suction source (not shown), a suction force is generated on the holding surface 65, and the inspection piece P is suction-held on the holding surface 65 by this suction force. The rotation drive unit 63 is, for example, an air cylinder or a motor, and is configured to rotate the holding surface 65 along the rotation shaft 62 parallel to the holding surface 65. More specifically, the rotation shaft 62 is oriented in the Y-axis direction, similar to the rotation shaft of the spindle 31.

[0064] In the inspection table 60, by rotating the rotation drive unit 63 to rotate the holding surface 65 (rotation holding unit 64), it is possible to switch between a state where the holding surface 65 is positioned at the processing position as shown in FIGS. 5 and 6, and a state where the holding surface 65 is positioned at the measurement position as shown in FIG. 7. More specifically, by rotating the rotation drive unit 63 to rotate the rotation holding unit 64 by 90° clockwise or counterclockwise around the rotation shaft 62, the position of the holding surface 65 can be switched between the processing position and the measurement position.

[0065] The processing position is the position where the holding surface 65 is horizontal. In the state where the holding surface 65 is at the processing position, the longitudinal direction of the holding surface 65 faces the Y-axis direction, and the short-side direction of the holding surface 65 faces the X-axis direction. That is, the holding surface 65 (its normal line) faces the vertical direction.

[0066] On the other hand, the measurement position is a position orthogonal to the processing position, that is, the position where the holding surface 65 is parallel to the vertical direction. In the state where the holding surface 65 is at the measurement position, the longitudinal direction of the holding surface 65 faces the Y-axis direction, and the short-side direction of the holding surface 65 faces the Z-axis direction. That is, the holding surface 65 (its normal line) faces the horizontal direction (X-axis direction).

[0067] As shown in FIG. 5, the planarization step S3 is carried out with the holding surface 65 positioned at the machining position. Specifically, while rotationally driving the spindle 31, the control unit 100 lowers the cutting blade 32 above the inspection table 60 and positions the cutting blade 32 at an arbitrarily set height (for example, 1 mm) with respect to the height of the holding surface detected in the holding surface height detection step S1. This corresponds to positioning at a predetermined depth from the upper surface PS when viewed from the upper surface PS side.

[0068] When the positioning of the cutting blade 32 in the Z-axis direction is completed, the control unit 100 relatively moves the cutting blade 32 in the Y-axis direction parallel to the rotation axis of the spindle 31 with respect to the inspection table 60 while keeping the spindle 31 rotationally driven, and scans the entire upper surface PS of the inspection piece P with the cutting blade 32. As a result, since the upper surface PS of the inspection piece P is shaved at a constant height by the cutting blade 32, the unevenness of the upper surface PS is eliminated and the inspection piece P is planarized.

[0069] When the inspection piece P is planarized, the control unit 100 detects the height 71 of the upper surface PS of the planarized inspection piece P with the height detector 70 as shown in FIG. 3(d) (detecting piece upper surface height detection step S4). The detecting piece upper surface height detection step S4 is the same as the conventional cutting edge position detection method.

[0070] When the height 71 of the upper surface PS of the inspection piece P is detected, the control unit 100 performs cutting on the inspection piece P with the cutting unit 30 (cutting blade 32) so that a cutting groove having a predetermined cutting depth set in advance is formed as shown in FIG. 3(e) (cutting groove formation step S5).

[0071] As shown in FIG. 6, the cutting groove forming step S5 is performed with the holding surface 65 positioned at the machining position. Specifically, while rotationally driving the spindle 31, the control unit 100 positions the cutting blade 32 at a height that results in a desired cutting depth (e.g., 0.5 mm) with respect to the test piece P based on the cutting edge position managed by the control unit 100, that is, the cutting edge position of the cutting blade 32 stored in advance. Further, while keeping the spindle 31 rotationally driven, the control unit 100 relatively moves the cutting blade 32 and the inspection table 60 in the X-axis direction orthogonal to the rotational axis direction of the spindle 31 for machining feed. As a result, as shown in FIG. 3(f), a cutting groove G is formed in the test piece P by the cutting blade 32. The cutting groove G is formed as a linear groove extending from one end face to the other end face of the holding surface 65 as the cutting blade 32 moves across the test piece P in the short side direction of the holding surface 65. The cutting groove forming step S5 is the same as the conventional cutting edge position detection method.

[0072] Thereafter, the control unit 100 measures the depth of the cutting groove G (cutting depth measurement step S6). As shown in FIG. 7, the cutting depth measurement step S6 is performed with the holding surface 65 positioned at a measurement position orthogonal to the machining position. That is, the holding surface 65 at the machining position and the holding surface 65 at the measurement position are orthogonal to each other.

[0073] Specifically, in the cutting depth measurement step S6, first, the control unit 100 rotates the rotation holding unit 64 by 90° by the rotation driving unit 63 to position the holding surface 65 on which the test piece P is held at the measurement position. As a result, the cross-section of the test piece P in which the cutting groove G is formed is oriented in the vertical direction. The cross-section of the test piece P refers to the side surface (end face) located at the short side end of the test piece P held on the holding surface 65.

[0074] When the holding surface 65 is positioned at the measurement position, as shown in FIG. 7, the control unit 100 moves the imaging unit 50 above the inspection table 60, positions the imaging unit 50 at a position facing the inspection piece P, and causes the imaging unit 50 to image the cross section of the inspection piece P. As a result, an image signal is transmitted from the imaging unit 50 to the control unit 100, and the control unit 100 processes the image signal sent from the imaging unit 50 to generate image data of an image of the cross section of the inspection piece P (for example, the image 90 shown in FIG. 8).

[0075] The control unit 100 further calculates the depth D of the cutting groove G from the image 90 of the cross section of the inspection piece P represented by the generated image data. The method for calculating the cutting groove G from the image 90 is not particularly limited and can be calculated by any known image processing.

[0076] Finally, the control unit 100 calculates the difference between the measured depth D of the cutting groove G and the desired cutting depth as a correction value, and corrects the cutting edge position of the cutting blade 32 (correction step S7). The correction step S7 is the same as the conventional cutting edge position detection method. That is, the cutting edge position managed by the cutting device 10 is corrected by the correction value, and the corrected cutting edge position is managed (stored) by the cutting device 10 as the cutting edge position of the cutting blade 32.

[0077] In the cutting edge position detection method according to the present embodiment, the cutting groove G is formed after the inspection piece P is flattened, and the depth of the formed cutting groove G is measured. By forming the cutting groove G after the inspection piece P is flattened, it is possible to prevent fluctuations in the height of the upper surface of the inspection piece P measured before and after cutting. As a result, since the reference position during cutting and the reference position during measurement can be made constant, by correcting the cutting edge position using the difference between the measured cutting depth and the desired cutting depth, the error between the managed cutting edge position and the actual cutting edge position can be accurately compensated.

[0078] Thus, in the cutting edge position detection method according to this embodiment, it is possible to accurately inspect the cutting edge position of the cutting blade 32, and as a result, the cutting edge position can be accurately corrected as necessary. Therefore, according to the cutting edge position detection method according to this embodiment, it is possible to control the cutting edge position with high precision.

[0079] <Second Embodiment> FIG. 9 is a flowchart showing the procedure of the cutting edge position detection method of the cutting blade according to this embodiment. As described above, the cutting edge position of the cutting blade 32 varies due to wear of the cutting blade 32. Therefore, it is desirable to periodically calculate and correct the error of the cutting edge position. In the first embodiment, each time correction is performed, the process starts from the holding surface height detection in step S1 of FIG. 4, but for some steps, the second and subsequent executions may be omitted.

[0080] As shown in FIG. 9, in the cutting edge position detection method of the cutting blade according to this embodiment, the processes from step S11 to step S14 are performed only for the first time, and for the second and subsequent times, only the processes from step S15 to step S17 may be repeated. Note that the processes from step S11 to step S17 are the same as the processes from step S1 to step S7 in FIG. 4.

[0081] That is, in the cutting edge position detection method according to this embodiment, when the cutting groove formation step (step S15), the cutting depth measurement step (step S16), and the correction step (step S17) are repeatedly performed, the upper surface height measurement step (step S14) for measuring the height of the upper surface PS of the flattened inspection piece P is provided after the flattening step (step S13) and before the first cutting groove formation step (step S15). And in this case, each of the repeatedly performed cutting groove formation steps (step S15) is performed in a state where the cutting blade 32 is positioned at a height corresponding to a desired cutting depth with respect to the height of the upper surface PS measured in the upper surface height measurement step (step S14) based on the previously stored cutting edge position of the cutting blade 32. That is, the height of the upper surface PS measured in step S14 is commonly used in each step S15.

[0082] According to the cutting edge position detection method according to this embodiment, when the cutting edge position is periodically corrected, it is not necessary to measure the height of the upper surface PS every time. As a result, the time required for correcting the cutting edge position per time can be shortened. Therefore, it can contribute to tact up.

[0083] The embodiments of the present invention are not limited to the above-described embodiments, and various changes, substitutions, and modifications may be made without departing from the spirit of the technical idea of the present invention. Furthermore, if the technical idea of the present invention can be realized in another way by technological progress or another derived technology, the method may be used for implementation. Therefore, the claims cover all embodiments that can be included within the scope of the technical idea of the present invention.

[0084] In the above-described embodiment, an example in which the cutting edge position detection method according to this embodiment is implemented by the cutting device 10 alone has been shown. However, the cutting edge position detection method may be implemented in cooperation with the cutting device 10 and other devices. Specifically, the cutting depth may be measured by a device different from the cutting device 10, and the cutting edge position of the cutting device 10 may be corrected based on the result.

[0085] For example, the cutting groove G formed in the test piece P by the cutting device 10 may be measured by a microscope device different from the cutting device 10, and in addition to the depth of the cutting groove G, the shape and the like may be measured together. Thereby, not only the change in the cutting edge position of the cutting blade 32 but also uneven wear of the cutting blade 32 can be detected. Therefore, in addition to correcting the cutting edge position, it may be possible to cause the notification unit 80 to notify whether or not the cutting blade 32 needs to be replaced as necessary.

Industrial Applicability

[0086] As described above, according to the cutting edge position detection method of the cutting blade of the present invention, the error of the cutting edge position can be accurately inspected and the cutting edge position can be accurately corrected. For this reason, it is possible to control the cutting process with high precision by a cutting device having a cutting blade, which is useful.

Explanation of Symbols

[0087] 10: Cutting device 11: Workpiece 22: Processing table 23: Processing holding surface 30: Cutting unit 31: Spindle 32: Cutting blade 60: Inspection table 61: Pedestal 62: Rotating shaft 63: Rotation drive unit 64: Rotation holding part 65: Holding surface 70: Height detector 71 - 73: Height 90: Image 100: Control unit D: Depth G: Cutting groove P: Inspection piece PS: Upper surface

Claims

1. A method for detecting the edge position of a cutting blade mounted at the tip of a spindle, comprising: a holding step of holding a test piece on a holding table; a flattening step of positioning the cutting blade at a predetermined depth from the upper surface of the test piece and relatively moving the cutting blade and the holding table to flatten the test piece; after the flattening step, positioning the cutting blade at a height that results in a desired cutting depth with respect to the test piece based on the pre-stored edge position of the cutting blade; a cutting groove forming step of relatively moving the cutting blade and the holding table to form a cutting groove in the test piece with the cutting blade; a cutting depth measuring step of measuring the depth of the cutting groove; a correcting step of calculating a difference between the depth of the cutting groove and the desired cutting depth as a correction value and correcting the edge position of the cutting blade. A method for detecting the edge position of a cutting blade, characterized by the above.

2. The holding table has a holding surface for holding the test piece, and a rotation driving unit for rotating the holding surface along a rotation axis parallel to the holding surface, the flattening step and the cutting groove forming step are performed with the holding surface positioned at the machining position, and the cutting depth measuring step is performed with the holding surface positioned at a measuring position orthogonal to the machining position. The method for detecting the edge position of a cutting blade according to claim 1, characterized by the above.

3. The cutting depth measuring step includes imaging the cross-section of the cutting groove, and calculating the depth of the cutting groove from the image of the imaged cross-section. The method for detecting the edge position of a cutting blade according to claim 1 or claim 2, characterized by the above.

4. Furthermore, when the cutting groove forming step, the cutting depth measuring step, and the correcting step are repeatedly performed, after the flattening step and before the first cutting groove forming step, an upper surface height measuring step of measuring the height of the upper surface of the flattened test piece is provided. Each of the repeatedly performed cutting groove forming steps is performed with the cutting blade positioned at a height that results in the desired cutting depth with respect to the height of the upper surface measured in the upper surface height measuring step based on the pre-stored edge position of the cutting blade. The method for detecting the edge position of a cutting blade according to claim 1 or claim 2, characterized by the above.

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