Machining method for cutting blades

Abstract

Reduces deformation of the dress board. [Solution] A cutting blade machining method is provided, comprising: a holding step of holding the dress board with the holding table while the second surface of the dress board and the holding surface of the holding table are in contact; a moving step of moving a cutting blade that rotates around a spindle and the holding table holding the dress board relatively along a first direction along the first surface of the dress board, wherein the moving step includes a first machining groove forming step of forming a first machining groove having a first depth from the first surface in a first region on a first elongated region along the first direction of the first surface; and a reinforcing portion remaining step of leaving the second region as a reinforcing portion by not forming a machining groove in a second region of the first surface on the first elongated region that is different from the first region, or by forming a second machining groove having a second depth of half or less of the first depth in a second region on the first elongated region.

Description

Technical Field

[0001] The present invention relates to a method for processing a cutting blade by dressing or truing the cutting blade using a dressing board having a plate shape.

Background Art

[0002] As a cutting device for cutting a workpiece, a cutting device is known that has a spindle and a cutting blade having an annular cutting edge mounted on the tip of the spindle. This cutting blade usually has a cutting edge containing abrasive grains and a bonding material.

[0003] Before cutting a workpiece with a cutting blade, dressing (i.e., sharpening the cutting edge) is usually performed on the cutting blade using a rectangular plate-shaped dressing board. By sharpening, the abrasive grains appropriately protrude from the bonding material, so that the cutting performance of the cutting blade can be appropriately exhibited.

[0004] When truing (i.e., correcting the shape of the cutting blade) is performed on the cutting blade, the dressing board is also cut with the cutting blade. By truing, the circumferential runout of the cutting blade can be reduced. Also, by so-called flat dress, which is a form of truing, the shape of the outer peripheral end of the cutting blade can be made substantially flat in a cross-sectional view passing through the radial direction of the cutting blade.

[0005] The dressing board is, for example, sucked and held on the upper surface of a holding table provided in the cutting device. The shape of the holding table in a top view is a rectangular shape substantially the same size as the dressing board. When dressing the cutting blade, for example, the lower end of the cutting blade rotating around the spindle is positioned at a predetermined depth that does not reach the lower surface of the dressing board from the upper surface of the dressing board.

[0006] In this state, the dress board is fed through the machine from a position outside one side of its outer edge, passing through that side and the other side on the opposite side, to a position outside the other side. As a result, a single machining groove is formed on the top surface of the dress board.

[0007] As machining grooves are formed, the cutting blade is dressed. However, when machining grooves are formed in the dressing board with the cutting blade, the residual stress in the dressing board is released, which can cause the dressing board to deform in a warped manner (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2011-9324 [Overview of the project] [Problems that the invention aims to solve]

[0009] When the deformation of the dressing board becomes large, the dressing board may lift off or detach from the holding table. The present invention has been made in view of these problems, and aims to reduce the deformation of the dressing board when processing the cutting blade by cutting the dressing board with the cutting blade in order to perform dressing and / or truing. [Means for solving the problem]

[0010] According to one aspect of the present invention, a method for processing a cutting blade, comprising: a holding step of holding the dressing board with the holding table while the holding surface of the holding table is in contact with the holding surface of the holding table, the cutting blade rotating around a spindle and the holding table holding the dressing board along the first surface A cutting blade machining method is provided, comprising: a moving step of moving the blade relatively, wherein the moving step includes a first machining groove forming step of forming a first machining groove having a first depth from the first surface in a first elongated region on the first surface along the first direction; and a reinforcing portion remaining step of not forming a machining groove in a second region of the first surface on the first elongated region that is different from the first region, or forming a second machining groove having a second depth of half or less of the first depth in the second region on the first elongated region, thereby leaving the second region as a reinforcing portion.

[0011] Preferably, in the reinforcement retention step, the second region is located in the outer peripheral region including the outer peripheral edge of the dress board on the first elongated region along the first direction.

[0012] Preferably, in the reinforcement retention step, the second region is located in the central region of the dressing board, away from the outer edge of the dressing board on the first elongated region along the first direction.

[0013] Preferably, the moving step further includes an index feed step of moving the cutting blade and the dress board relative to each other such that the cutting blade is located on a second elongated region that is perpendicular to the first direction on the first surface and is separated from the first elongated region by a predetermined index feed amount and is aligned with the first direction; an additional first machining groove forming step of forming an additional first machining groove having the first depth in the first region on the second elongated region; and an additional reinforcement remaining step of leaving the second region as a reinforcement by not forming a machining groove in a second region of the first surface on the second elongated region that is different from the first region, or by forming an additional second machining groove having a second depth of half or less of the first depth in the second region on the second elongated region.

[0014] Preferably, after the additional reinforcement remaining step, two or more of the second regions are adjacent in the second direction, and the total length from end to end of the two or more adjacent second regions in the second direction is at least twice the index feed amount. [Effects of the Invention]

[0015] A method for machining a cutting blade according to one aspect of the present invention comprises a holding step and a moving step. The moving step comprises a first machining groove forming step of forming a first machining groove having a first depth from the first surface in a first region on a first elongated region along a first direction on the first surface, and a reinforcement portion retention step of leaving the second region as a reinforcement portion by not forming a machining groove in a second region of the first surface on the first elongated region that is different from the first region, or by forming a second machining groove having a second depth of half or less of the first depth in a second region on the first elongated region.

[0016] In this way, in the first region on the first elongated region of the dressing board, machining of the cutting blade (i.e., at least one of truing and dressing) can be performed by forming a first machining groove. In addition, in the second region on the first elongated region, the dressing board is not cut or is cut more shallowly than in the first region, so the presence of the second region reduces deformation of the dressing board.

Brief Description of the Drawings

[0017] [Figure 1] It is a perspective view schematically showing a cutting device. [Figure 2] It is a perspective view schematically showing an enlarged cutting blade. [Figure 3] It is a flowchart of a method for processing a cutting blade. [Figure 4] It is a flowchart of a moving process in the first embodiment. [Figure 5] FIG. 5(A) is a top view schematically showing a reinforcing portion remaining process, FIG. 5(B) is a partial cross-sectional side view schematically showing a reinforcing portion remaining process, FIG. 5(C) is a top view schematically showing a descending process, FIG. 5(D) is a partial cross-sectional side view schematically showing a descending process, FIG. 5(E) is a top view schematically showing a first processing groove forming process, FIG. 5(F) is a partial cross-sectional side view schematically showing a first processing groove forming process, FIG. 5(G) is a top view schematically showing an ascending process and a reinforcing portion remaining process, and FIG. 5(H) is a partial cross-sectional side view schematically showing an ascending process and a reinforcing portion remaining process. [Figure 6] FIG. 6(A) is a top view of a dressing board in which a first processing groove and an additional first processing groove are formed, and FIG. 6(B) is a cross-sectional view taken along line A-A of FIG. 6(A). [Figure 7] FIG. 7(A) is a top view of a dressing board in which a second processing groove and a first processing groove are formed, and FIG. 7(B) is a cross-sectional view taken along line B-B of FIG. 7(A). [Figure 8] It is a flowchart of a moving process in the second embodiment. [Figure 9] FIG. 9(A) is a top view of a dressing board in which a first processing groove and an additional first processing groove are formed, and FIG. 9(B) is a cross-sectional view taken along line C-C of FIG. 9(A). [Figure 10] FIG. 10(A) is a top view of a dressing board in which a second processing groove and a first processing groove are formed, and FIG. 10(B) is a cross-sectional view taken along line D-D of FIG. 10(A). [Figure 11] It is a flowchart of a moving process in the third embodiment. [Figure 12]FIG. 12(A) is a top view of a dressing board in which a first processing groove is formed, and FIG. 12(B) is a cross-sectional view taken along line E-E of FIG. 12(A). [Figure 13] FIG. 13(A) is a top view of a dressing board in which a second processing groove and a first processing groove are formed, and FIG. 13(B) is a cross-sectional view taken along line F-F of FIG. 13(A). [Figure 14] FIG. 14(A) is a top view schematically showing a reinforcing part remaining step in the fourth embodiment, FIG. 14(B) is a partial cross-sectional side view schematically showing the reinforcing part remaining step, FIG. 14(C) is a top view schematically showing a lowering step, FIG. 14(D) is a partial cross-sectional side view schematically showing the lowering step, FIG. 14(E) is a top view schematically showing a first processing groove forming step, FIG. 14(F) is a partial cross-sectional side view schematically showing the first processing groove forming step, FIG. 14(G) is a top view schematically showing a rising step and a reinforcing part remaining step, and FIG. 14(H) is a partial cross-sectional side view schematically showing the rising step and the reinforcing part remaining step. [Figure 15] FIG. 15(A) is a top view of a dressing board in which a first processing groove and a plurality of additional first processing grooves are formed in the fourth embodiment, FIG. 15(B) is a cross-sectional view taken along line G1-G1 of FIG. 15(A), FIG. 15(C) is a top view of a dressing board in which a second processing groove, a plurality of additional second processing grooves, a first processing groove, and a plurality of additional first processing grooves are formed in a modified example of the reinforcing part remaining step of the fourth embodiment, and FIG. 15(D) is a cross-sectional view taken along line G2-G2 of FIG. 15(C). [Figure 16] FIG. 16(A) is a top view of a dressing board in which a first processing groove is formed in the fifth embodiment, FIG. 16(B) is a cross-sectional view taken along line H1-H1 of FIG. 16(A), FIG. 16(C) is a top view of a dressing board in which a second processing groove and a first processing groove are formed in a modified example of the reinforcing part remaining step of the fifth embodiment, and FIG. 16(D) is a cross-sectional view taken along line H2-H2 of FIG. 16(C). [Figure 17]Figure 17(A) is a top view of a dress board in which a first machined groove and an additional first machined groove are formed in the sixth embodiment; Figure 17(B) is a cross-sectional view of Figure 17(A) taken along the line I1-I1; Figure 17(C) is a cross-sectional view of Figure 17(A) taken along the line J1-J1; Figure 17(D) is a top view of a dress board in which a second machined groove and a first machined groove are formed in a modified example of the reinforcement remaining process in the sixth embodiment; Figure 17(E) is a cross-sectional view of Figure 17(D) taken along the line I2-I2; and Figure 17(F) is a cross-sectional view of Figure 17(D) taken along the line J2-J2. [Figure 18] Figure 18(A) is a top view of a dress board in which the first machining groove is formed in the seventh embodiment, Figure 18(B) is a cross-sectional view of Figure 18(A) along the line K1-K1, Figure 18(C) is a top view of a dress board in which the second machining groove and the first machining groove are formed in a modified example of the reinforcement remaining process in the seventh embodiment, and Figure 18(D) is a cross-sectional view of Figure 18(C) along the line K2-K2. [Modes for carrying out the invention]

[0018] (First Embodiment) An embodiment of one aspect of the present invention will be described with reference to the attached drawings. First, a cutting device 2 (see Figure 1) will be described, and then a cutting blade 46 (see Figure 2) on which at least one of dressing (i.e., sharpening, straightening) and truing (i.e., shape correction, reshaping) is performed using a dressing board 21 (see Figure 1) will be described.

[0019] Figure 1 is a schematic perspective view of the cutting device 2. Note that in Figure 1, some of the components of the cutting device 2 are shown as functional blocks. Also, in the following description, the X, Y, and Z axes are orthogonal to each other.

[0020] The X-axis is approximately parallel to the machining feed direction, and the Y-axis is approximately parallel to the indexing feed direction and the indexing feed direction. The Z-axis is approximately parallel to the upward and downward directions. The cutting device 2 is equipped with a base 4 that supports or houses each component.

[0021] An opening 4a is formed at the front corner of the base 4, and a cassette elevator 6, which moves up and down by a lifting mechanism (not shown), is provided inside this opening 4a. A cassette 8 for accommodating multiple workpieces 11 is placed on the upper surface of the cassette elevator 6. In Figure 1, the cassette 8 is shown by a dashed line.

[0022] The workpiece 11 is, for example, a disc-shaped wafer made of a semiconductor material such as silicon. Multiple devices are formed on the surface of the workpiece 11. The workpiece 11 is housed in a cassette 8 as a workpiece unit 17 supported by a metal annular frame 15 via a dicing tape 13.

[0023] A rectangular opening 4b is formed on the side of the cassette elevator 6, with its longer side aligned with the X-axis direction. An X-axis movement mechanism (not shown) having a ball screw and a motor is located at the bottom of the opening 4b. The X-axis movement mechanism moves the chuck table 16 and sub-chuck table 18, which will be described later, along the X-axis (i.e., feeds them for machining).

[0024] A rectangular table cover 12 is provided on the upper part of the X-axis movement mechanism, and bellows-shaped cover members 14 that can expand and contract along the X axis are provided on both sides of the table cover 12 in the X-axis direction. A chuck table 16 that holds the workpiece 11 by suction is positioned on the table cover 12.

[0025] A rotational drive source (not shown), such as a motor, is provided at the bottom of the chuck table 16, and the chuck table 16 is rotatable within a predetermined angular range around a rotation axis substantially parallel to the Z-axis direction.

[0026] The chuck table 16 has a disc-shaped frame made of non-porous metal. A disc-shaped recess is provided in the center of the frame, and a disc-shaped porous plate made of porous ceramics is fixed in this recess. It is connected to a suction source (not shown), such as a vacuum pump, and the negative pressure generated by the suction source is transmitted to the upper surface of the porous plate.

[0027] The upper surface of the chuck table 16 is substantially parallel to the XY plane and functions as a holding surface 16a for suction holding of the workpiece 11. Four clamping units 16b are provided around the chuck table 16 for clamping the annular frame 15 in the thickness direction.

[0028] Sub-chuck tables (holding tables) 18 are provided at each of the two corners of the table cover 12. In Figure 1, the two sub-chuck tables 18 are provided at two corners on one side of the table cover 12 in the X-axis direction, separated along the Y-axis direction.

[0029] The sub-chuck tables 18 are integrated with the chuck table 16 and can move along the X-axis together with the chuck table 16 by an X-axis movement mechanism. Each sub-chuck table 18 is smaller than the chuck table 16 and has a rectangular shape when viewed from above.

[0030] The sub-chuck table 18 includes a pair of sides arranged substantially parallel to the X-axis direction and a pair of sides arranged substantially parallel to the Y-axis direction. The upper surface of the sub-chuck table 18 is provided with a grid of multiple suction grooves (not shown).

[0031] Each suction groove is connected to the aforementioned suction source (not shown), and negative pressure is transmitted to each suction groove. The area of ​​the upper surface of the subchuck table 18 excluding the multiple suction grooves is substantially flat and functions as a holding surface 18a for suction holding of the rectangular plate-shaped dress board 21.

[0032] The dimensions of the dress board 21 are, for example, 75 mm in length, 75 mm in width, and 1.0 mm in thickness. However, the dimensions of the dress board 21 are not limited to these. The shape of the dress board 21 should be approximately the same as the shape of the retaining surface 18a, and it may be a square or a rectangle.

[0033] The dress board 21 is formed, for example, by molding and firing a mixed material in which abrasive grains such as white alundum (WA) and green carbon (GC) are mixed with a bonding material such as vitrified resin. The average particle size of the abrasive grains that make up the dress board 21 is usually smaller than the average particle size of the abrasive grains that make up the cutting blade 46.

[0034] The dress board 21 may be fixed and integrated with a support substrate (not shown) made of resin, metal, or the like. In this case, the laminate composed of the dress board 21 and the support substrate is held by suction using the sub-chuck table 18 so that the dress board 21 is exposed upwards.

[0035] The dress board 21 has an upper surface (i.e., first surface) 21a into which the cutting blade 46 is cut, and a lower surface (i.e., second surface) 21b located on the opposite side from the upper surface 21a in the thickness direction 21c of the dress board 21 (see Figure 5(B), etc.). This lower surface 21b is held by suction at the holding surface 18a of the subchuck table 18.

[0036] When the cutting blade 46 cuts into the upper surface 21a of the dressing board 21, the abrasive grains of the dressing board 21 scrape away the bonding material of the cutting blade 46, or the abrasive grains of the cutting blade 46 detach from the bonding material. This results in dressing and truing of the cutting blade 46.

[0037] A first transport unit (not shown) is positioned above the opening 4b to transport the workpiece unit 17 to the chuck table 16. In addition, a pair of positioning guide rails (not shown) are provided in the loading and unloading area above the opening 4b and near the opening 4a to position the workpiece unit 17.

[0038] After the first transport unit transports one workpiece unit 17 from the cassette 8 to a pair of positioning guide rails, the position of the workpiece unit 17 is adjusted by the pair of positioning guide rails, and then the workpiece unit 17 is held in place by suction on the chuck table 16.

[0039] The chuck table 16, which holds the workpiece unit 17 by suction, moves along the X-axis to the opposite side of the loading / unloading area (i.e., to the processing area located directly below the gate-shaped support structure 20). The support structure 20 is positioned to the side and above the opening 4b, straddling the opening 4b.

[0040] A set of cutting unit moving mechanisms 22 is provided on the front of the support structure 20. Each cutting unit moving mechanism 22 is located on the front of the support structure 20 and shares a pair of guide rails 24 that are substantially parallel in the Y-axis direction.

[0041] A movable plate 26 is slidably attached to the guide rail 24. A nut portion (not shown) is provided on the back surface of the movable plate 26, and a screw shaft 28, which is arranged substantially parallel to the Y-axis direction, is rotatably connected to this nut portion.

[0042] A motor 30, such as a servo motor or a stepping motor, is connected to one end of the screw shaft 28. When the motor 30 rotates the screw shaft 28, the movable plate 26 moves along the guide rail 24.

[0043] Note that in Figure 1, only the motor 30 connected to one screw shaft 28 is shown, while the motor 30 connected to the other screw shaft 28 is hidden by the moving plate 26. The pair of guide rails 24, the moving plate 26, the nut section, the screw shafts 28, the motors 30, etc. constitute a Y-axis movement unit.

[0044] The Y-axis movement unit is used to primarily truing the cutting blade 46 (described in detail later) by moving the cutting unit 40 (described in detail later) relative to the dress board 21 in the Y-axis direction, and also when indexing and feeding the cutting unit 40 relative to the dress board 21.

[0045] A pair of guide rails 32 are provided on the surface of the movable plate 26, arranged substantially parallel to the Z-axis direction. The movable plate 34 is slidably mounted on the pair of guide rails 32. A nut portion (not shown) is provided on the back side of the movable plate 34, and a screw shaft 36, arranged substantially parallel to the Z-axis direction, is rotatably connected to this nut portion.

[0046] A motor 38, such as a servo motor or a stepping motor, is connected to the upper end of the screw shaft 36. When the motor 38 rotates the screw shaft 36, the movable plate 34 moves along the Z-axis direction.

[0047] A pair of guide rails 32, a moving plate 34, a nut section, a screw shaft 36, a motor 38, etc. constitute a Z-axis movement unit that moves the cutting unit 40, including the cutting blade 46, along the Z-axis.

[0048] The Z-axis movement unit is used when moving the cutting unit 40 up and down relative to the dress board 21, when adjusting the cutting depth of the cutting blade 46 relative to the dress board 21, etc.

[0049] A cutting unit 40 is connected to the lower part of the movable plate 34. The cutting apparatus 2 of this embodiment has a so-called facing dual spindle structure, and the pair of cutting units 40 are arranged so as to be mirror-symmetric with respect to a virtual plane parallel to the XZ plane.

[0050] The cutting unit 40 has a rectangular tubular spindle housing 42. A portion of a cylindrical spindle 44 (see Figure 2) is housed in the spindle housing 42 in a manner that allows it to rotate by a hydrostatic air bearing (i.e., an air bearing). A stator (not shown) is provided inside the spindle housing 42 for rotating the spindle 44, which is integrated with a rotor.

[0051] The rotor and stator constitute the motor, and the spindle 44 is capable of high-speed rotation. The longitudinal direction of the spindle 44 is aligned with the Y-axis. A cutting blade 46 having an annular cutting edge is mounted at the tip of the spindle 44.

[0052] Figure 2 is a schematic, enlarged perspective view of a so-called hub-type cutting blade 46. A disc-shaped blade mount 50 is fixed to the tip of the spindle 44 by a male screw 48. The blade mount 50 has a cylindrical boss portion 50a into which the central opening 46a of the cutting blade 46 is inserted. A male screw is provided on the outer circumference of the tip of the boss portion 50a.

[0053] The female thread of the fixing nut 52 is fastened to the male thread of the boss portion 50a. The blade mount 50 has a flange portion with a larger diameter than the boss portion 50a. The cutting blade 46 is mounted on the tip of the spindle 44 by clamping the cutting blade 46 in the Y-axis direction between the flange portion of the blade mount 50 and the fixing nut 52.

[0054] Therefore, when the spindle 44 rotates at high speed, the cutting blade 46 rotates at high speed around the spindle 44 (i.e., around the spindle 44). Note that the cutting blade 46 is not limited to the hub type described above, but may also be a hubless type (washer type).

[0055] Now, let's return to Figure 1. A microscope camera unit 54 is provided on the side of the spindle housing 42. The microscope camera unit 54 has a solid-state image sensor, a lens, etc. The image obtained through the microscope camera unit 54 is used for positioning the cutting blade 46, etc.

[0056] In the Y-axis direction, a circular opening 4c is provided on the opposite side of opening 4a from the central opening 4b. A spinner cleaning unit 56 for cleaning the workpiece 11 after cutting is provided inside opening 4c.

[0057] After cutting, the workpiece 11 is transported from the chuck table 16 to the spinner cleaning unit 56 by a second transport unit (not shown). After cleaning, the workpiece unit 17 is transported into the cassette 8 via a pair of positioning guide rails by the first transport unit.

[0058] A touch panel display (not shown) is provided on the side of the cutting device 2. The touch panel display functions as an input device for inputting operator instructions to the cutting device 2, and as a display device for displaying images, GUI (Graphical User Interface), etc.

[0059] The cassette elevator 6, X-axis movement mechanism, rotational drive source, clamp unit 16b, negative pressure transmission from suction source to chuck table 16, negative pressure transmission from suction source to sub-chuck table 18, cutting unit movement mechanism 22, cutting unit 40, microscope camera unit 54, spinner cleaning unit 56, touch panel display, etc., are controlled by the controller 58.

[0060] The controller 58 is composed of a computer that includes, for example, a processor represented by a CPU (Central Processing Unit) and memory. The memory includes main memory such as DRAM (Dynamic Random Access Memory) and auxiliary storage such as flash memory, hard disk drive, and solid-state drive.

[0061] The auxiliary storage device stores software that includes a predetermined program for executing the machining method of the cutting blade 46, which will be described later. The functions of the controller 58 are realized by operating the processor and other components according to this software.

[0062] The specified program may be stored on a non-temporary tangible recording medium such as a USB (Universal Serial Bus) memory, optical disc, SD memory card, or HDD (hard disk drive) instead of an auxiliary storage device.

[0063] Before cutting the workpiece 11 with the cutting blade 46, at least one of dressing and truing of the cutting blade 46 is performed using the dressing board 21. For example, a general truing procedure will be described.

[0064] In typical truing operations, first, with the spindle 44 rotating at high speed, the cutting blade 46 is positioned outside the dressing board 21 in the Y-axis direction of the XY top view using the X-axis movement mechanism and the cutting unit movement mechanism 22, and the lower end 46b of the cutting blade 46 (see Figure 5(B), etc.) is positioned at a height slightly lower than the upper surface 21a of the dressing board 21.

[0065] Next, the cutting unit 40 is moved along the Y-axis from one side 21a1 of the dress board 21 to the other side 21a2 opposite to side 21a1 (see Figure 5(A), etc.). As a result, a single machining groove is formed on the upper surface 21a of the dress board 21, traversing from one side 21a1 to the other side 21a2, along the movement trajectory of the lower end 46b. In addition, multiple machining grooves may be formed discretely in the X-axis direction, each along the Y-axis direction.

[0066] In this specification, a machining groove means a bottomed groove formed in the dressing board 21 by bringing a cutting blade 46 rotating around the spindle 44 into contact with the dressing board 21.

[0067] Furthermore, to explain the case of general dressing, first, with the X-axis movement mechanism and spindle 44 rotating at high speed, the cutting unit movement mechanism 22 is used to position the cutting blade 46 outside the dressing board 21 in the X-axis direction in the XY top view, and the lower end 46b of the cutting blade 46 (see Figure 14(B), etc.) is positioned at a height slightly lower than the upper surface 21a of the dressing board 21.

[0068] Next, the sub-chuck table 18 is moved along the X-axis so that the lower end 46b of the cutting blade 46 moves from one side 21a1 of the dress board 21 to the opposite side 21a2. As a result, a single machining groove is formed on the upper surface 21a of the dress board 21, traversing from one side 21a1 to the other side 21a2 along the movement trajectory of the lower end 46b. In addition, multiple machining grooves may be formed discretely in the Y-axis direction, each along the X-axis direction.

[0069] Normally, truing and / or dressing is performed as described above in order to make the most effective use of the area of ​​the dressing board 21. At this time, a machined groove is formed on the upper surface 21a, connecting one side 21a1 to the other side 21a2. When a machined groove is formed in this way, the dressing board 21 may deform in a way that causes it to warp.

[0070] Furthermore, when the power supply to the cutting device 2 is turned off and negative pressure is no longer supplied to the upper surface of the sub-chuck table 18, or when the negative pressure supplied to each sub-chuck table 18 decreases due to negative pressure being supplied to multiple cutting devices 2 from a single negative pressure source, the warped dress board 21 may not be properly held in place by suction on the sub-chuck table 18.

[0071] Therefore, in the first embodiment, when truing the cutting blade 46, measures are taken to reduce the warping of the dress board 21. Figure 3 is a flowchart of the machining method for the cutting blade 46, including the holding step S10 and the moving step S20.

[0072] In the holding process S10, the dress board 21 is held by the sub-chuck table 18 by suction while the lower surface 21b of the dress board 21 is in contact with the holding surface 18a of the sub-chuck table 18 (see Figure 1).

[0073] In the holding process S10, for example, an operator manually places the dressing board 21 on the sub-chuck table 18, and then the holding surface 18a of the sub-chuck table 18 holds the dressing board 21 by suction.

[0074] However, if the cutting device 2 has a transport mechanism capable of transporting the dress board 21, the transport mechanism may transport the dress board 21, which is housed in the cassette 8, to the sub-chuck table 18.

[0075] After the holding step S10, the spindle 44 is rotated at a predetermined rotational speed, and then the cutting unit 40 (i.e., the cutting blade 46) and the sub-chuck table 18 holding the dress board 21 are moved relative to each other along the first direction 21a3 in a moving step S20. The direction of rotation of the spindle 44 is not particularly limited.

[0076] Figure 4 is a flowchart of the moving process S20 in the first embodiment. In the moving process S20, truing (e.g., flat dressing) of the cutting blade 46 is mainly performed, but dressing of the cutting blade 46 may be performed simultaneously with truing. Of course, truing alone may also be performed.

[0077] Referring to Figures 4 and 5(A) to 5(H), the movement process S20 in Figure 3 will be explained in detail. Note that Figures 5(A) to 5(H) show a portion of the cutting blade 46 near the lower end 46b that cuts the dress board 21.

[0078] The movement process S20 includes the reinforcement portion remaining process S21, the lowering process S22, the first processing groove forming process S23, the raising process S24, the reinforcement portion remaining process S25, the judgment process S26, and the index feeding process S27, as shown in Figure 4.

[0079] In the moving process S20 of this embodiment, first, the reinforcement portion retention process S21 is performed (see Figures 5(A) and 5(A)). In the reinforcement portion retention process S21, the lower end 46b of the cutting blade 46 is positioned above the upper surface 21a of the dress board 21, outside one side 21a1 of the dress board 21 in the Y-axis direction of the XY top view.

[0080] Then, in this state, the cutting unit moving mechanism 22 moves the cutting blade 46 along the Y axis from directly above the dress board 21 and outside one side 21a1 of the upper surface 21a to a position that passes over the side 21a1 and is inside the side 21a1 by a first predetermined distance (for example, 2 mm).

[0081] Figure 5(A) is a schematic top view showing the reinforcement remaining process S21 of Figure 4. In Figure 5(A), the first elongated region 23 encompassing the area where the cutting blade 46 is scheduled to move is shown by a dashed line, and the first region 23a in the first elongated region 23 where cutting is performed by the cutting blade 46 is shown by a dashed line. Figure 5(B) is a schematic partial cross-sectional side view showing the reinforcement remaining process S21 of Figure 4.

[0082] The first elongated region 23 and the first region 23a are aligned along a first direction 21a3 (a direction along the upper surface 21a, which is approximately parallel to the Y-axis in Figures 5(A) and 5(B)) that extends from one side 21a1 to the other side 21a2 of the upper surface 21a, and have a predetermined width in the X-axis direction according to the cutting depth of the cutting blade 46, as will be described later.

[0083] In this embodiment, in the second region 23b1, which is a region on the first elongated region 23 that is different from the first region 23a, a machining groove is not formed in the second region 23b1 near one side 21a1 of the upper surface 21a, leaving an uncut area. The uncut second region 23b1 functions as a reinforcing part that reduces warping of the dress board 21.

[0084] After the reinforcement remaining process S21, the lowering process S22 is performed (see Figures 5(C) and 5(D)). In the lowering process S22, the movement of the cutting blade 46 in the Y-axis direction is stopped, and the cutting unit moving mechanism 22 lowers the lower end 46b of the cutting blade 46 along the Z-axis from the upper surface 21a of the dress board 21 to the position of the first depth 21d.

[0085] Figure 5(C) is a schematic top view showing the descent process S22 in Figure 4, and Figure 5(D) is a schematic partial cross-sectional side view showing the descent process S22 in Figure 4. After the descent process S22, with the movement of the cutting blade 46 in the Z-axis direction stopped, the movement of the cutting blade 46 in the Y-axis direction is restarted, and the first machining groove forming process S23 is performed (see Figures 5(E) and 5(F)).

[0086] In the first machining groove forming step S23, the cutting unit moving mechanism 22 positions the lower end 46b of the cutting blade 46 at a first depth 21d from the upper surface 21a of the dress board 21, and then moves the cutting blade 46 along the Y axis to a position inward by a first predetermined distance (for example, 2 mm) from the other side 21a2.

[0087] This forms a first machining groove 25 having a first depth 21d in the dress board 21. The position inward by a first predetermined distance from the other side 21a2 is a position in the first direction 21a3 that is further away by a second predetermined distance from a position that is a first predetermined distance from one side 21a1. The second predetermined distance is, for example, 71 mm.

[0088] Figure 5(E) is a schematic top view showing the first machining groove formation process S23 of Figure 4, and Figure 5(F) is a schematic partial cross-sectional side view showing the first machining groove formation process S23 of Figure 4. In the first machining groove formation process S23, cutting fluid such as pure water is supplied at a predetermined flow rate to the contact area between the cutting blade 46 and the dress board 21.

[0089] After the first machining groove forming step S23, the lifting step S24 is performed (see Figures 5(G) and 5(H)). In the lifting step S24, the movement of the cutting blade 46 in the Y-axis direction is stopped, and the cutting unit moving mechanism 22 raises the lower end 46b of the cutting blade 46 above the upper surface 21a of the dress board 21.

[0090] After the lifting process S24, the reinforcement remaining process S25 is performed (see Figures 5(G) and 5(H)). In the reinforcement remaining process S25, with the lower end 46b of the cutting blade 46 positioned above the upper surface 21a, the cutting unit moving mechanism 22 moves the cutting blade 46 along the Y axis to return it to the position at the start of the reinforcement remaining process S21.

[0091] As a result, in the first direction 21a3, an uncut second region 23b2 remains at the end of the first machined groove 25. Figure 5(G) is a schematic top view showing the lifting process S24 and the reinforcement remaining process S25, and Figure 5(H) is a schematic partial cross-sectional side view showing the lifting process S24 and the reinforcement remaining process S25.

[0092] In this embodiment, in the second region 23b2, which is a different region from the first region 23a on the first elongated region 23 and is located near the other side 21a2 of the upper surface 21a, an uncut region is left without forming a machined groove. The uncut second region 23b2 also functions as a reinforcing portion that reduces warping of the dress board 21.

[0093] If index feeding is not performed after the reinforcement remaining process S25 (decision step S26 is NO), the flow is terminated. On the other hand, if index feeding is performed to form additional machined grooves (decision step S26 is YES), index feeding is performed (index feeding process S27).

[0094] In the index feeding process S27, the sub-chuck table 18 is moved by the X-axis movement mechanism, thereby moving the cutting blade 46 in a second direction 21a4 (see Figure 6(A)) that is perpendicular to the first direction 21a3 on the upper surface 21a.

[0095] As shown in Figure 6(A), when the cutting unit 40 (i.e., the cutting blade 46) and the sub-chuck table 18 (i.e., the dressing board 21) are moved relative to each other, the cutting blade 46 is located in the second direction 21a4, separated from the first elongated region 23 by a predetermined index feed amount 27, and on the second elongated region 29 along the first direction 21a3.

[0096] After the index feeding process S27, the reinforcement remaining process S21 to S25 described above is repeated. Figure 6(A) is a top view of the dress board 21 in which the first processed groove 25 and additional first processed groove 25 are formed, and Figure 6(B) is a cross-sectional view AA of Figure 6(A).

[0097] In the additional reinforcement remaining step S21, an uncut area is left in the second region 29b1 on the second elongated region 29, near one side 21a1 of the upper surface 21a, which is different from the first region 29a, without forming a machined groove. The uncut second region 29b1 also functions as a reinforcement that reduces warping of the dress board 21.

[0098] In the additional first machining groove forming step S23, an additional first machining groove 25 having a first depth 21d is formed in the first region 29a on the second elongated region 29. Furthermore, in the additional reinforcement remaining step S25, an uncut region is left without forming a machining groove in the second region 29b2 on the second elongated region 29, near the other side 21a2 of the upper surface 21a, which is different from the first region 29a. The uncut second region 29b2 also functions as a reinforcement to reduce warping of the dress board 21.

[0099] As shown in Figure 6(A), in the reinforcement remaining process S25 and the additional reinforcement remaining process S25, the second regions 23b1, 23b2, 29b1, and 29b2 are located in the outer peripheral region of the upper surface 21a, including the outer peripheral edge of the dress board 21 on the first elongated region 23.

[0100] The outer peripheral region of the upper surface 21a includes, for example, a strip-shaped region near side 21a1 that has a width of one-quarter the length of side 21a1 and whose longitudinal direction is aligned with the second direction 21a4, and a strip-shaped region near side 21a2 that has a width of one-quarter the length of side 21a2 and whose longitudinal direction is aligned with the second direction 21a4, starting from the edge of side 21a2.

[0101] As shown in Figure 6(A), after the additional reinforcement remaining process S25, two or more second regions 23b1, 29b1 are adjacent in the second direction 21a4 with an uncut region due to index feed in between. The same applies to two or more second regions 23b2, 29b2.

[0102] Depending on the diameter of the cutting blade 46, the first depth 21d, etc., the total length 33 from end to end in the second direction 21a4 of two adjacent second regions 23b1, 29b1 is, for example, more than twice the index feed rate 27. The same applies to two or more second regions 23b2, 29b2.

[0103] However, the second regions 23b2 and 29b2 do not necessarily have to be separate in the second direction 21a4; they may be connected. If the second regions 23b2 and 29b2 are connected in the second direction 21a4, then the first machining grooves 25 formed in the first regions 23a and 29a are also connected in the second direction 21a4. The same applies to two or more second regions 23b2 and 29b2.

[0104] Since the dress board 21 tends to warp in the second direction 21a4 which is perpendicular to the longitudinal direction of the first processed groove 25 (i.e., the first direction 21a3), providing two or more sufficiently long second regions 23b1, 29b1 in the second direction 21a4 allows the dress board to function more reliably as a reinforcing part.

[0105] In Figure 6(A), for the sake of clarity, the first machining groove 25 and the additional first machining groove 25 are shown in an exaggeratedly large size. However, when actually truing the cutting blade 46, more than 10 machining grooves are formed on the upper surface 21a of the dressing board 21. That is, the number of times the index feed process S27 is performed may be two or more, and is not particularly limited.

[0106] For example, when truing a cutting blade 46, ten machining grooves with a depth of 20 μm are sequentially formed under the following machining conditions, followed by forty machining grooves with a depth of 10 μm, and then twenty machining grooves with a depth of 5 μm. Each machining groove has the shape shown in Figures 6(A) and 6(B) and is arranged at different positions on the upper surface 21a.

[0107] Cutting blade thickness: 1.0 mm Spindle rotation speed: 30,000 rpm Y-axis movement speed: 50 mm / s Cutting fluid flow rate: 4.0 L / min Index feed amount: 1.3mm Cutting depth (first depth): 5 μm or more and 20 μm or less

[0108] In this way, the cutting blade 46 can be machined by forming the first machining groove 25 in the first elongated region 23a of the dress board 21. In addition, since the dress board 21 is not machined in the second regions 23b1 and 23b2 of the first elongated region 23, the presence of the second regions 23b1 and 23b2 reduces deformation of the dress board 21.

[0109] The first region 29a on the second elongated region 29 and the second regions 29b1, 29b2 on the second elongated region 29 also have the same function as the first region 23a and the second regions 23b1, 23b2. In this embodiment, the uncut region including the second regions 23b1, 23b2, 29b1, 29b2 in the outer peripheral region of the dress board 21 forms a continuous rectangle.

[0110] In particular, since the uncut regions including the second regions 23b1 and 23b2, and the uncut regions including the second regions 29b1 and 29b2, respectively, extend from edge to edge of the upper surface 21a of the dress board 21 along the second direction 21a4, deformation of the dress board 21 can be effectively reduced.

[0111] Although only two first machining grooves 25 are shown in Figure 6(A), of course, as mentioned in the example of machining conditions, three or more first machining grooves 25 may be formed in parallel in the second direction 21a4.

[0112] (Modified Version) A modified version of the first embodiment will be described with reference to Figures 7(A) and 7(B). Note that explanations of aspects common to the first embodiment may be omitted. The movement step S20 of this modified version is also performed according to the flow shown in Figure 4.

[0113] In the reinforcement portion retention process S21, instead of leaving the second region 23b1 as an uncut region, a relatively shallow second machining groove 35 is formed in the second region 23b1, thereby leaving the second region 23b1 as a reinforcement portion. The second machining groove 35 has a second depth 21e that is less than half the first depth 21d.

[0114] The second depth 21e can be as shallow as it is, as long as it is less than or equal to half the first depth 21d. However, for the purpose of clearly distinguishing it from the first embodiment, the second depth 21e is greater than 0.0 μm and less than or equal to half the first depth 21d. The width of the second direction 21a4 of the second processed groove 35 is smaller than the width of the second direction 21a4 of the first processed groove 25.

[0115] The lowering process S22 and the first machining groove forming process S23 following the reinforcement portion remaining process S21 are the same as in the first embodiment. However, in the raising process S24, in order to form the second machining groove 35 in the second region 23b2, the lower end 46b of the cutting blade 46 is raised from the upper surface 21a of the dress board 21 to the aforementioned shallow second depth 21e.

[0116] In the reinforcement portion retention process S25, which follows the upward process S24, a relatively shallow second machining groove 35 is formed in the second region 23b2 in the same manner as in the reinforcement portion retention process S21, thereby leaving the second region 23b2 as a reinforcement portion. If index feeding is not performed (NO in the decision process S26), the flow is terminated.

[0117] In contrast, if index feeding is performed (YES in the decision step S26), the process returns to the reinforcement portion remaining step S21. Then, in the same manner, an additional second machining groove 35 is formed in the second region 29b1 on the second elongated region 29 (additional reinforcement portion remaining step S21).

[0118] Furthermore, after the downward process S22, an additional first machining groove 25 is formed in the first region 29a on the second elongated region 29 (additional first machining groove formation process S23), and then, after the upward process S24, an additional second machining groove 35 is formed in the second region 29b2 on the second elongated region 29 (additional reinforcement remaining process S25).

[0119] Figure 7(A) is a top view of the dress board 21 in which the second machining groove 35 and the first machining groove 25 are formed, and Figure 7(B) is a cross-sectional view of BB in Figure 7(A). Of course, as mentioned above, the number of times the index feed process S27 is performed may be two or more, and is not particularly limited.

[0120] (Second Embodiment) The second embodiment will be described with reference to Figures 8, 9(A), and 9(B). Note that explanations of aspects common to the first embodiment may be omitted. Figure 8 is a flowchart of the movement process S20 in the second embodiment.

[0121] Figure 9(A) is a top view of the dress board 21 in which the first machining groove 25 and an additional first machining groove 25 are formed, and Figure 9(B) is a cross-sectional view of Figure 9(A). In the second embodiment, the second regions 23b and 29b are located in the central region in the first direction 21a3 on the upper surface 21a of the dress board 21, away from the outer peripheral edge of the dress board 21 on the first elongated region 23.

[0122] The central region of the upper surface 21a in the first direction 21a3 includes, for example, a strip-shaped region whose longitudinal direction is aligned with the second direction 21a4, from a position one-quarter the length of side 21a1 along the first direction 21a3 from the edge of side 21a1 to a position one-quarter the length of side 21a1 in the opposite direction to the first direction 21a3 from the edge of side 21a2.

[0123] Each step will be explained according to the flow chart in Figure 8. In this embodiment as well, the truing processing conditions described above can be applied. First, with the lower end 46b of the cutting blade 46 positioned at a first depth 21d from the upper surface 21a of the dress board 21, the cutting blade 46 is moved along the Y axis from outside one side 21a1 of the dress board 21 to a position a predetermined distance inward from one side 21a1 (first processing groove forming step S31).

[0124] As a result, a first machining groove 25 having a first depth 21d is formed in the first region 23a on the first elongated region 23 along the first direction 21a3 of the upper surface 21a of the dress board 21, extending from the upper surface 21a.

[0125] Next, the movement of the cutting blade 46 in the Y-axis direction is stopped, and the lower end 46b of the cutting blade 46 is raised to a position above the upper surface 21a of the dress board 21 (raising step S32).

[0126] After the lifting process S32, with the lower end 46b of the cutting blade 46 positioned above the upper surface 21a of the dress board 21, the cutting blade 46 is moved along the Y axis by a predetermined distance in the first direction 21a3 (reinforcement remaining process S33).

[0127] As a result, in the second region 23b, which is a different region from the first region 23a on the first elongated region 23, a machining groove is not formed in the central region of the upper surface 21a, leaving an uncut area. The uncut second region 23b functions as a reinforcing part that reduces warping of the dress board 21.

[0128] After the reinforcement remaining process S33, the lower end 46b of the cutting blade 46 is lowered from the upper surface 21a of the dress board 21 to the first depth 21d (lowering process S34). Then, after the lowering process S34, the movement of the cutting blade 46 in the Y-axis direction is resumed.

[0129] With the lower end 46b of the cutting blade 46 positioned at the first depth 21d, the cutting blade 46 is moved along the Y-axis until it is positioned outside the other side 21a2 of the dress board 21 (first machining groove forming step S35).

[0130] In this manner, by moving the cutting unit 40 (i.e., the cutting blade 46) and the dressing board 21 (i.e., the sub-chuck table 18) relative to each other along the first direction 21a3, the first machining groove 25 is formed in each of the pair of first regions 23a on the first elongated region 23 which is positioned to sandwich the uncut second region 23b.

[0131] Next, if index feeding is not performed (NO in decision step S36), the flow is terminated. However, if index feeding is performed to form additional machining grooves (YES in decision step S36), index feeding is performed (index feeding step S37).

[0132] After the index feed process S37, the additional first machining groove formation process S31 to the additional first machining groove formation process S35 is performed. As shown in Figure 9(A), in the reinforcement portion remaining process S33 and the additional reinforcement portion remaining process S33, the second regions 23b and 29b are located in the central region of the upper surface 21a of the dress board 21.

[0133] The two second regions 23b and 29b are adjacent in the second direction 21a4, with an uncut region between them due to the index feed. The total length 33 from end to end of the two adjacent second regions 23b and 29b in the second direction 21a4 is, for example, more than twice the index feed amount 27.

[0134] Of course, the case is not limited to having one second region 23b and one second region 29b, but two or more second regions 29b may be provided. Even when there are a total of three or more second regions 23b, 29b, the total length 33 from end to end in the second direction 21a4 is, for example, twice or more the index feed amount 27.

[0135] In this embodiment as well, deformation of the dress board 21 can be reduced. In particular, since the uncut area including the second regions 23b and 29b extends like a spine from edge to edge along the second direction 21a4 from the upper surface 21a of the dress board 21, deformation of the dress board 21 can be effectively reduced.

[0136] (Modified Version) A modified version of the second embodiment will be described with reference to Figures 10(A) and 10(B). The movement step S20 of this modified version is also performed according to the flow shown in Figure 8. Figure 10(A) is a top view of the dress board 21 in which the second machining groove 35 and the first machining groove 25 are formed, and Figure 10(B) is a cross-sectional view of Figure 10(A) DD.

[0137] In the modified example's reinforcement retention step S33, instead of leaving the second regions 23b and 29b as uncut regions, relatively shallow second machined grooves 35 are formed in the second regions 23b and 29b, thereby leaving the second regions 23b and 29b as reinforced regions.

[0138] As described above, the second machining groove 35 has a second depth 21e that is less than or equal to half of the first depth 21d. In this modified example as well, the number of times the index feed process S27 is performed may be two or more, and is not particularly limited.

[0139] (Third Embodiment) The third embodiment will be described with reference to Figures 11, 12(A), and 12(B). Note that explanations of aspects common to the above embodiments may be omitted. Figure 11 is a flowchart of the movement process S20 in the third embodiment.

[0140] Figure 12(A) is a top view of the dress board 21 in which the first machining groove 25 and an additional first machining groove 25 are formed, and Figure 12(B) is a cross-sectional view of Figure 12(A). In the third embodiment, the second regions 23b and 29b are provided only in the vicinity of the other side 21a2 of the outer peripheral region of the dress board 21, and the second regions 23b and 29b are not provided in the vicinity of one side 21a1.

[0141] The third embodiment differs from the first embodiment in this respect, but is otherwise substantially the same as the first embodiment. Each step will be explained according to the flow chart in Figure 11.

[0142] First, in the first machining groove forming step S41, with the lower end 46b of the cutting blade 46 positioned at a first depth 21d from the upper surface 21a of the dress board 21, the cutting blade 46 is moved along the Y axis from outside one side 21a1 of the dress board 21 to a position three predetermined distances inward from the side 21a1.

[0143] This creates a first machining groove 25 having a first depth 21d from the upper surface 21a in a first elongated region 23 on the upper surface 21a of the dress board 21, along the first direction 21a3. The third predetermined distance is, for example, the sum of the first predetermined distance and the second predetermined distance described above.

[0144] After the first machining groove forming step S41, the lifting step S42 is performed. In the lifting step S42, the movement of the cutting blade 46 in the Y-axis direction is stopped, and the lower end 46b of the cutting blade 46 is raised to a position above the upper surface 21a of the dress board 21.

[0145] After the lifting process S42, the reinforcement remaining process S43 is performed. In the reinforcement remaining process S43, with the lower end 46b of the cutting blade 46 positioned above the upper surface 21a of the dress board 21, the cutting blade 46 is moved along the Y axis to return the cutting blade 46 to the position it was in at the start of the first machining groove forming process S41.

[0146] As a result, a machined groove is not formed in the second region 23b on the outer periphery of the upper surface 21a, which is a different region from the first region 23a on the first elongated region 23, leaving an uncut area. The uncut second region 23b functions as a reinforcing part that reduces warping of the dress board 21.

[0147] In this way, by moving the cutting unit 40 (i.e., the cutting blade 46) and the dressing board 21 (i.e., the sub-chuck table 18) relative to each other along the first direction 21a3, a first machining groove 25 is formed near one side 21a1, leaving an uncut second region 23b near the other side 21a2.

[0148] Next, if index feeding is not performed (NO in decision step S44), the flow is terminated. However, if index feeding is performed to form additional machining grooves (YES in decision step S44), index feeding is performed (index feeding step S45).

[0149] After the index feed process S45, the process from the additional first machining groove formation process S41 to the additional reinforcement portion retention process S43 is performed. As shown in Figure 12(A), in the reinforcement portion retention process S43 and the additional reinforcement portion retention process S43, there are second regions 23b and 29b in the outer peripheral region of the upper surface 21a of the dress board 21.

[0150] The two second regions 23b and 29b are adjacent in the second direction 21a4, with an uncut region between them due to the index feed. The total length 33 from end to end of the two adjacent second regions 23b and 29b in the second direction 21a4 is, for example, more than twice the index feed amount 27.

[0151] Of course, the case is not limited to having one second region 23b and one second region 29b, but two or more second regions 29b may be provided. Even when there are a total of three or more second regions 23b, 29b, the total length 33 from end to end in the second direction 21a4 is, for example, twice or more the index feed amount 27.

[0152] In this embodiment as well, deformation of the dress board 21 can be reduced. In particular, since the uncut region including the second regions 23b and 29b extends from one end to the other end of the upper surface 21a of the dress board 21 along the second direction 21a4 in the vicinity of the other side 21a2 of the dress board 21, deformation of the dress board 21 can be effectively reduced.

[0153] (Modified Version) A modified version of the third embodiment will be described with reference to Figures 13(A) and 13(B). This modified version is also carried out according to the flow shown in Figure 11. Figure 13(A) is a top view of the dress board 21 in which the second machining groove 35 and the first machining groove 25 are formed, and Figure 13(B) is an FF cross-sectional view of Figure 13(A).

[0154] In the modified example's reinforcement retention step S43, instead of leaving the second regions 23b and 29b as uncut regions, relatively shallow second machined grooves 35 are formed in the second regions 23b and 29b, thereby leaving the second regions 23b and 29b as reinforced areas.

[0155] As described above, the second machining groove 35 has a second depth 21e that is less than or equal to half of the first depth 21d. In this modified example as well, the number of times the index feed process S27 is performed may be two or more, and is not particularly limited.

[0156] (Fourth Embodiment) Next, the fourth embodiment will be described with reference to Figures 14(A) to 14(H) and Figures 15(A) and 15(B). In the fourth embodiment as well, the first machined groove 25 and the reinforcing portion are formed according to the flow shown in Figures 3 and 4.

[0157] However, in the moving step S20 of the fourth embodiment, the cutting unit 40 (i.e., the cutting blade 46) and the sub-chuck table 18 holding the dress board 21 are moved relative to each other along the first direction 21a3. For example, relative movement along the first direction 21a3 is achieved by moving the sub-chuck table 18 along the X-axis direction.

[0158] Dressing of the cutting blade 46 is primarily performed by moving the dressing board 21 relatively while the cutting blade 46 is embedded in the dressing board 21. However, truing may be performed on the cutting blade 46 simultaneously with the dressing. Of course, dressing alone may also be performed.

[0159] The movement process S20 of the fourth embodiment will be described in detail. First, the reinforcement portion retention process S21 is performed. In the reinforcement portion retention process S21, the lower end 46b of the cutting blade 46 is positioned above the upper surface 21a of the dress board 21, outside one side 21a1 of the dress board 21 in the X-axis direction of the XY top view.

[0160] Then, in this state, the sub-chuck table 18 is moved along the X-axis by the X-axis movement mechanism so that the lower end 46b of the cutting blade 46 moves from directly above the dress board 21 and outside one side 21a1 of the upper surface 21a to a position that passes over the side 21a1 and is inside the side 21a1 by a fourth predetermined distance (for example, 2 mm).

[0161] Figure 14(A) is a schematic top view showing the reinforcement remaining process S21. In Figure 14(A), the first elongated region 23 encompassing the area where the cutting blade 46 is scheduled to move is shown by a dashed line, and the first region 23a in the first elongated region 23 where cutting is performed by the cutting blade 46 is shown by a dashed line. Figure 14(B) is a schematic partial cross-sectional side view showing the reinforcement remaining process S21.

[0162] The first elongated region 23 and the first region 23a are aligned along a first direction 21a3 (the first direction 21a3 is aligned with the upper surface 21a and is substantially parallel to the X-axis) that extends from one side 21a1 to the other side 21a2 of the upper surface 21a, and have a predetermined width in the Y-axis direction according to the cutting blade thickness of the cutting blade 46.

[0163] In this embodiment, in the second region 23b1, which is a region on the first elongated region 23 that is different from the first region 23a, a machining groove is not formed in the second region 23b1 near one side 21a1 of the upper surface 21a, leaving an uncut area. The uncut second region 23b1 functions as a reinforcing part that reduces warping of the dress board 21.

[0164] After the reinforcement remaining process S21, the lowering process S22 is performed. In the lowering process S22, the movement of the sub-chuck table 18 in the X-axis direction is stopped, and the cutting unit moving mechanism 22 lowers the lower end 46b of the cutting blade 46 along the Z-axis from the upper surface 21a of the dress board 21 to the position of the first depth 21d.

[0165] Figure 14(C) is a schematic top view showing the lowering process S22, and Figure 14(D) is a schematic partial cross-sectional side view showing the lowering process S22. After the lowering process S22, the first machining groove forming process S23 is performed. In the first machining groove forming process S23, the movement of the cutting blade 46 in the Z-axis direction is stopped, and the movement of the sub-chuck table 18 in the X-axis direction is resumed.

[0166] That is, with the lower end 46b of the cutting blade 46 positioned at a first depth 21d from the upper surface 21a of the dress board 21, the sub-chuck table 18 is moved along the X-axis until the lower end 46b of the cutting blade 46 reaches a position four predetermined distances inward from the other side 21a2.

[0167] This forms a first machined groove 25 having a first depth 21d in the dress board 21. The position four predetermined distances inward from the other side 21a2 is a position five predetermined distances away from the position four predetermined distances away from the side 21a1 in the first direction 21a3. The fifth predetermined distance is, for example, 71 mm.

[0168] Figure 14(E) is a schematic top view showing the first machining groove formation process S23, and Figure 14(F) is a schematic cross-sectional view showing the first machining groove formation process S23. In the first machining groove formation process S23, cutting fluid such as pure water is supplied at a predetermined flow rate to the contact area between the cutting blade 46 and the dress board 21.

[0169] After the first machining groove forming step S23, the lifting step S24 is performed. In the lifting step S24, the movement of the sub-chuck table 18 in the X-axis direction is stopped, and the cutting unit moving mechanism 22 raises the lower end 46b of the cutting blade 46 above the upper surface 21a of the dressing board 21.

[0170] After the lifting process S24, the reinforcement remaining process S25 is performed. In the reinforcement remaining process S25, with the lower end 46b of the cutting blade 46 positioned above the upper surface 21a, the sub-chuck table 18 is moved along the X-axis by the X-axis movement mechanism to return the cutting blade 46 to the position it was in at the start of the reinforcement remaining process S21.

[0171] As a result, in the first direction 21a3, an uncut second region 23b2 remains at the end of the first machined groove 25. Figure 14(G) is a schematic top view showing the lifting process S24 and the reinforcement remaining process S25, and Figure 14(H) is a schematic partial cross-sectional side view showing the lifting process S24 and the reinforcement remaining process S25.

[0172] In the second region 23b2, which is a different region from the first region 23a on the first elongated region 23 and is located near the other side 21a2 of the upper surface 21a, an uncut region is left without forming a machined groove. The uncut second region 23b2 functions as a reinforcing part that reduces warping of the dress board 21.

[0173] If index feeding is not performed after the reinforcement remaining process S25 (decision step S26 is NO), the flow is terminated. On the other hand, if index feeding is performed to form additional machined grooves (decision step S26 is YES), index feeding is performed (index feeding process S27).

[0174] In the index feed process S27, the cutting unit moving mechanism 22 moves the cutting blade 46 along the Y axis, causing the cutting blade 46, which has returned to the outside of one side 21a1, to move in the second direction 21a4.

[0175] In this manner, when the cutting unit 40 (i.e., the cutting blade 46) and the sub-chuck table 18 (i.e., the dressing board 21) are moved relative to each other, the cutting blade 46 is positioned in the second direction 21a4 at a predetermined index feed amount 27 away from the first elongated region 23 and on the second elongated region 29 along the first direction 21a3.

[0176] After the index feeding process S27, the reinforcement portion remaining process S21 to S25 described above is repeated. Figure 15(A) is a top view of the dress board 21 in which the first machined groove 25 and a plurality of additional first machined grooves 25 are formed in the fourth embodiment, and Figure 15(B) is a cross-sectional view of Figure 15(A) taken along the line G1-G1.

[0177] In the additional reinforcement remaining step S21, an uncut area is left in the second region 29b1 on the second elongated region 29, near one side 21a1 of the upper surface 21a, which is different from the first region 29a, without forming a machined groove. The uncut second region 29b1 functions as a reinforcement that reduces warping of the dress board 21.

[0178] In the additional first machining groove formation step S23, an additional first machining groove 25 having a first depth 21d is formed in the first region 29a on the second elongated region 29. Furthermore, in the additional reinforcement remaining step S25, an uncut region is left without forming a machining groove in the second region 29b2 on the second elongated region 29, near the other side 21a2 of the upper surface 21a, which is different from the first region 29a. The uncut second region 29b2 also functions as a reinforcement to reduce warping of the dress board 21.

[0179] As shown in Figure 15(A), in the reinforcement remaining process S25, the second regions 23b1 and 23b2 are located in the outer peripheral region of the upper surface 21a, including the outer peripheral edge of the dress board 21 on the first elongated region 23, and in the additional reinforcement remaining process S25, the second regions 29b1 and 29b2 are located in the outer peripheral region of the upper surface 21a, including the outer peripheral edge of the dress board 21 on the second elongated region 29.

[0180] Furthermore, after the additional reinforcement remaining process S25, two or more second regions 23b1, 29b1 are adjacent in the second direction 21a4 with an uncut region resulting from index feeding in between. The same applies to two or more second regions 23b2, 29b2.

[0181] Depending on the diameter of the cutting blade 46, the first depth 21d, etc., the total length 33 from end to end in the second direction 21a4 of two adjacent second regions 23b1, 29b1 is, for example, more than twice the index feed rate 27. The same applies to two or more second regions 23b2, 29b2.

[0182] Since the dress board 21 tends to warp in the second direction 21a4 which is perpendicular to the first direction 21a3 which is the longitudinal direction of the first processed groove 25, providing two or more second regions 23b1, 29b1 that are sufficiently long in the second direction 21a4 will allow it to function more reliably as a reinforcing part.

[0183] Note that in Figure 15(A), the first machining groove 25 and the additional first machining groove 25 are exaggerated and shown larger for ease of explanation. However, when actually dressing the cutting blade 46, more than 10 machining grooves are formed on the upper surface 21a of the dressing board 21. In other words, the number of times the index feed process S27 is performed may be two or more, and is not particularly limited.

[0184] For example, when dressing the cutting blade 46, ten machining grooves with a depth of 300 μm are sequentially formed at a machining feed rate of 10 mm / s under the following machining conditions: then ten machining grooves with a depth of 300 μm are sequentially formed at a machining feed rate of 20 mm / s; and then ten machining grooves with a depth of 300 μm are sequentially formed at a machining feed rate of 30 mm / s. Each machining groove has the shape shown in Figures 15(A) and 15(B) and is positioned at different locations on the upper surface 21a.

[0185] Cutting blade thickness: 200 μm Spindle rotation speed: 30,000 rpm X-axis movement speed: 10 mm / s to 30 mm / s Cutting fluid flow rate: 4.0 L / min Index feed rate: 500 μm Cutting depth (first depth): 300 μm

[0186] In this way, the cutting blade 46 can be machined by forming the first machining groove 25 in the first elongated region 23a of the dress board 21. In addition, since the dress board 21 is not machined in the second regions 23b1 and 23b2 of the first elongated region 23, the presence of the second regions 23b1 and 23b2 reduces deformation of the dress board 21.

[0187] The first region 29a on the second elongated region 29 and the second regions 29b1, 29b2 on the second elongated region 29 also have the same function as the first region 23a and the second regions 23b1, 23b2. In this embodiment, the uncut region including the second regions 23b1, 23b2, 29b1, 29b2 in the outer peripheral region of the dress board 21 forms a continuous rectangle.

[0188] In particular, since the uncut regions including the second regions 23b1 and 23b2, and the uncut regions including the second regions 29b1 and 29b2, respectively, extend from edge to edge of the upper surface 21a of the dress board 21 along the second direction 21a4, deformation of the dress board 21 can be effectively reduced.

[0189] (Modified Version) A modified version of the fourth embodiment will be described with reference to Figures 15(C) and 15(D). The movement process S20 of this modified version is also carried out according to the flow shown in Figure 4. In the reinforcement portion retention process S21, instead of leaving the second region 23b1 as an uncut region, a relatively shallow second machining groove 35 is formed in the second region 23b1, thereby leaving the second region 23b1 as a reinforced portion.

[0190] The second machined groove 35 has a second depth 21e that is less than or equal to half the first depth 21d. The second depth 21e can be as shallow as it is, as long as it is less than or equal to half the first depth 21d. However, for the purpose of clearly distinguishing it from the first embodiment, the second depth 21e is greater than 0.0 μm and less than or equal to half the first depth 21d.

[0191] The lowering process S22 and the first machining groove forming process S23, following the reinforcement portion remaining process S21, are the same as in the fourth embodiment. However, in the raising process S24, in order to form the second machining groove 35 in the second region 23b2, the lower end 46b of the cutting blade 46 is raised from the upper surface 21a of the dress board 21 to the aforementioned shallow second depth 21e.

[0192] In the reinforcement portion retention process S25, which follows the upward process S24, a relatively shallow second machining groove 35 is formed in the second region 23b2 in the same manner as in the reinforcement portion retention process S21, thereby leaving the second region 23b2 as a reinforcement portion. If index feeding is not performed (NO in the decision process S26), the flow is terminated.

[0193] In contrast, if index feeding is performed (YES in the decision step S26), the process returns to the reinforcement portion remaining step S21. Then, in the same manner, an additional second machining groove 35 is formed in the second region 29b1 on the second elongated region 29 (additional reinforcement portion remaining step S21).

[0194] Furthermore, after the downward process S22, an additional first machining groove 25 is formed in the first region 29a on the second elongated region 29 (additional first machining groove formation process S23), and then, after the upward process S24, an additional second machining groove 35 is formed in the second region 29b2 on the second elongated region 29 (additional reinforcement remaining process S25).

[0195] Figure 15(C) is a top view of a dress board 21 in which a second machining groove 35 and a plurality of additional second machining grooves 35, and a first machining groove 25 and a plurality of additional first machining grooves 25 are formed, in a modified example of the reinforcement remaining process S21, S25 of the fourth embodiment. Figure 15(D) is a cross-sectional view taken along the line G2-G2 in Figure 15(C). Of course, as described above, the number of times the index feeding process S27 is performed may be two or more, and is not particularly limited.

[0196] (Fifth Embodiment) The fifth embodiment will be described with reference to Figures 16(A) and 16(B). Note that some details common to the embodiments already described may be omitted. In the fifth embodiment, the first machining groove 25 and the reinforcing portion are formed according to the flow shown in Figure 8.

[0197] Figure 16(A) is a top view of the dress board 21 in which the first machining groove 25 and an additional first machining groove 25 are formed, and Figure 16(B) is a cross-sectional view of Figure 16(A) taken along the line H1-H1. In the fifth embodiment, a second region 23b is located in the central region of the upper surface 21a of the dress board 21, away from the outer edge of the dress board 21, on the first elongated region 23, and similarly, a second region 29b is located in the central region of the upper surface 21a on the second elongated region 29.

[0198] Each step will be explained according to the flow chart in Figure 8. In this embodiment as well, the processing conditions for the dressing described above can be applied. First, the first processing groove formation step S31 is performed. In the first processing groove formation step S31, the lower end 46b of the cutting blade 46 is positioned from the upper surface 21a of the dressing board 21 to a first depth 21d.

[0199] In this state, the sub-chuck table 18 is moved along the X-axis so that the lower end 46b of the cutting blade 46 moves from outside one side 21a1 of the dress board 21 to a position a predetermined distance inward from one side 21a1.

[0200] As a result, a first machining groove 25 having a first depth 21d is formed in the first region 23a on the first elongated region 23 along the first direction 21a3 of the upper surface 21a of the dress board 21, extending from the upper surface 21a.

[0201] Next, the lifting process S32 is performed. In the lifting process S32, the movement of the sub-chuck table 18 in the X-axis direction is stopped, and the lower end 46b of the cutting blade 46 is raised to a position above the upper surface 21a of the dress board 21.

[0202] After the lifting process S32, the reinforcement remaining process S33 is performed. In the reinforcement remaining process S33, with the lower end 46b of the cutting blade 46 positioned above the upper surface 21a of the dress board 21, the sub-chuck table 18 is moved along the X-axis so that the lower end 46b of the cutting blade 46 moves a predetermined distance along the first direction 21a3.

[0203] As a result, a machined groove is not formed in the second region 23b in the central region of the upper surface 21a, which is a different region from the first region 23a on the first elongated region 23, leaving an uncut area. The uncut second region 23b functions as a reinforcing part that reduces warping of the dress board 21.

[0204] After the reinforcement remaining process S33, the lowering process S34 is performed. In the lowering process S34, the lower end 46b of the cutting blade 46 is lowered from the upper surface 21a of the dress board 21 to the first depth 21d. Then, after the lowering process S34, the first machining groove forming process S35 is performed.

[0205] In the first machining groove forming step S35, the movement of the sub-chuck table 18 in the X-axis direction is resumed. That is, with the lower end 46b of the cutting blade 46 positioned at the first depth 21d, the sub-chuck table 18 is moved along the X-axis until the cutting blade 46 is positioned outside the other side 21a2 of the dress board 21.

[0206] In this manner, by moving the cutting unit 40 (i.e., the cutting blade 46) and the dressing board 21 (i.e., the sub-chuck table 18) relative to each other along the first direction 21a3, the first machining grooves 25 are formed in each of the pair of first regions 23a on the first elongated region 23, which are positioned to sandwich the uncut second region 23b.

[0207] Next, if index feeding is not performed (decision step S36 is NO), the flow is terminated. However, if index feeding is performed to form additional machining grooves (decision step S36 is YES), index feeding is performed (index feeding step S37). After the index feeding step S37, the additional first machining groove formation steps S31 to S35 are performed.

[0208] As shown in Figure 16(A), in the reinforcement remaining process S33 and the additional reinforcement remaining process S33, there are second regions 23b and 29b in the central region of the upper surface 21a of the dress board 21.

[0209] The two second regions 23b and 29b are adjacent in the second direction 21a4, with an uncut region between them due to the index feed. The total length 33 from end to end of the two adjacent second regions 23b and 29b in the second direction 21a4 is, for example, more than twice the index feed amount 27.

[0210] Of course, the case is not limited to having one second region 23b and one second region 29b, but two or more second regions 29b may be provided. Even when there are a total of three or more second regions 23b, 29b, the total length 33 from end to end in the second direction 21a4 is, for example, twice or more the index feed amount 27.

[0211] In this embodiment as well, deformation of the dress board 21 can be reduced. In particular, since the uncut area including the second regions 23b and 29b extends like a spine from edge to edge along the second direction 21a4 from the upper surface 21a of the dress board 21, deformation of the dress board 21 can be effectively reduced.

[0212] (Modified Version) A modified version of the fifth embodiment will be described with reference to Figures 16(C) and 16(D). The moving process S20 of this modified version is also carried out according to the flow shown in Figure 8. Figure 16(C) is a top view of the dress board 21 in which the second processing groove 35 and the first processing groove 25 are formed, and Figure 16(D) is a cross-sectional view of Figure 16(C) taken along line H2-H2.

[0213] In the reinforcement portion retention process S33 of the modified example, instead of leaving the second regions 23b and 29b as uncut regions, relatively shallow second machining grooves 35 are formed in the second regions 23b and 29b, thereby leaving the second regions 23b and 29b as reinforcement portions.

[0214] As described above, the second machining groove 35 has a second depth 21e that is less than or equal to half of the first depth 21d. In this modified example as well, the number of times the index feed process S27 is performed may be two or more, and is not particularly limited.

[0215] (Sixth Embodiment) The sixth embodiment will be described with reference to Figures 17(A) to 17(C). Note that some details common to the embodiments already described may be omitted. In the sixth embodiment, the first machining groove 25 and the reinforcing portion are formed according to the flow shown in Figure 8.

[0216] Figure 17(A) is a top view of a dress board 21 in which the first machining groove 25 and an additional first machining groove 25 are formed in the sixth embodiment, Figure 17(B) is a cross-sectional view of Figure 17(A) taken along the line I1-I1, and Figure 17(C) is a cross-sectional view of Figure 17(A) taken along the line J1-J1.

[0217] In the sixth embodiment, a first group of narrow groove regions 41 in which the second regions 23b and 29b are in the same range in the first direction 21a3, and a second group of narrow groove regions 43 in which the second regions 23b and 29b are in the same range in the first direction 21a3 are formed on the upper surface 21a of the dress board 21.

[0218] In the sixth embodiment, for convenience, in each of the first groove region group 41 and the second groove region group 43, one elongated region is referred to as the first elongated region 23, and the other elongated region is referred to as the second elongated region 29.

[0219] In both the first groove region group 41 and the second groove region group 43, the second regions 23b and 29b are located in the central region of the upper surface 21a. However, the second regions 23b and 29b of the first groove region group 41 and the second regions 23b and 29b of the second groove region group 43 are located in different ranges in the first direction 21a3.

[0220] The second regions 23b and 29b of the first groove region group 41 are located closer to one side 21a1 than the second regions 23b and 29b of the second groove region group 43, and the second regions 23b and 29b of the second groove region group 43 are located closer to the other side 21a2 than the second regions 23b and 29b of the first groove region group 41.

[0221] In other words, the second regions 23b and 29b of the first group of narrow groove regions 41 and the second regions 23b and 29b of the second group of narrow groove regions 43 are arranged in a zigzag pattern on the upper surface 21a. By adjusting the machining feed amount when forming the first machined groove 25 and the reinforcing portion, the machining configuration shown in Figure 17(A) can be achieved.

[0222] In this embodiment as well, the warping of the dress board 21 can be reduced by the second regions 23b and 29b of the first group of narrow groove regions 41 and the second region 23b and 29b of the second group of narrow groove regions 43.

[0223] (Modified Version) A modified version of the sixth embodiment will be described with reference to Figures 17(D) to 17(F). The movement process S20 of this modified version is also carried out according to the flow shown in Figure 8. Figure 17(D) is a top view of the dress board 21 in which the second processing groove 35 and the first processing groove 25 are formed in a modified version of the reinforcement remaining process S33 of the sixth embodiment.

[0224] Figure 17(E) is a cross-sectional view of I2-I2 in Figure 17(D), and Figure 17(F) is a cross-sectional view of J2-J2 in Figure 17(D). In the reinforcement retention process S33 of the modified example, instead of leaving the second regions 23b and 29b as uncut regions, relatively shallow second machined grooves 35 are formed in the second regions 23b and 29b, thereby leaving the second regions 23b and 29b as reinforced areas.

[0225] As described above, the second machining groove 35 has a second depth 21e that is less than or equal to half of the first depth 21d. In this modified example as well, the number of times the index feed process S27 is performed may be two or more, and is not particularly limited.

[0226] (Seventh Embodiment) The seventh embodiment will be described with reference to Figures 18(A) and 18(B). Note that some details common to previously described embodiments may be omitted. In the seventh embodiment, the first machining groove 25 and the reinforcing portion are formed according to the flow shown in Figure 11.

[0227] Figure 18(A) is a top view of the dress board 21 in which the first machining groove 25 is formed in the seventh embodiment, and Figure 18(B) is a cross-sectional view of Figure 18(A) along the line K1-K1. In the seventh embodiment, the second regions 23b and 29b are provided only in the vicinity of the other side 21a2 of the outer peripheral region of the dress board 21, and the second regions 23b and 29b are not provided in the vicinity of one side 21a1.

[0228] In the moving process S20, first, the first machining groove forming process S41 is performed. In the first machining groove forming process S41, with the lower end 46b of the cutting blade 46 positioned at a first depth 21d from the upper surface 21a of the dress board 21, the sub-chuck table 18 is moved along the X-axis so that the lower end 46b of the cutting blade 46 moves from outside one side 21a1 of the dress board 21 to a position six predetermined distances inward from one side 21a1.

[0229] This creates a first machining groove 25 having a first depth 21d from the upper surface 21a in a first elongated region 23 on the upper surface 21a of the dress board 21, along the first direction 21a3. The sixth predetermined distance is, for example, the sum of the fourth predetermined distance and the fifth predetermined distance.

[0230] After the first machining groove forming step S41, the lifting step S42 is performed. In the lifting step S42, the movement of the sub-chuck table 18 in the X-axis direction is stopped, and the lower end 46b of the cutting blade 46 is raised to a position above the upper surface 21a of the dressing board 21.

[0231] After the lifting process S42, the reinforcement remaining process S43 is performed. In the reinforcement remaining process S43, with the lower end 46b of the cutting blade 46 positioned above the upper surface 21a of the dress board 21, the sub-chuck table 18 is moved along the X axis to return the cutting blade 46 to the position it was in at the start of the first machining groove forming process S41.

[0232] As a result, a machined groove is not formed in the second region 23b on the outer periphery of the upper surface 21a, which is a different region from the first region 23a on the first elongated region 23, leaving an uncut area. The uncut second region 23b functions as a reinforcing part that reduces warping of the dress board 21.

[0233] In this way, by moving the cutting unit 40 (i.e., the cutting blade 46) and the dressing board 21 (i.e., the sub-chuck table 18) relative to each other along the first direction 21a3, a first machining groove 25 is formed near one side 21a1, leaving an uncut second region 23b near the other side 21a2.

[0234] Next, if index feeding is not performed (NO in decision step S44), the flow is terminated. However, if index feeding is performed to form additional machining grooves (YES in decision step S44), index feeding is performed (index feeding step S45).

[0235] After the index feed process S45, the additional first machining groove formation process S41 to the additional reinforcement portion retention process S43 are performed again. As shown in Figure 18(A), in the reinforcement portion retention process S43 and the additional reinforcement portion retention process S43, there are second regions 23b and 29b in the outer peripheral region of the upper surface 21a of the dress board 21.

[0236] The two second regions 23b and 29b are adjacent in the second direction 21a4, with an uncut region between them due to the index feed. The total length 33 from end to end of the two adjacent second regions 23b and 29b in the second direction 21a4 is, for example, more than twice the index feed amount 27.

[0237] Of course, the case is not limited to having one second region 23b and one second region 29b, but two or more second regions 29b may be provided. Even when there are a total of three or more second regions 23b, 29b, the total length 33 from end to end in the second direction 21a4 is, for example, twice or more the index feed amount 27.

[0238] (Modified Version) A modified version of the seventh embodiment will be described with reference to Figures 18(C) and 18(D). This modified version is also carried out according to the flow shown in Figure 11. Figure 18(C) is a top view of the dress board 21 in which the second machining groove 35 and the first machining groove 25 are formed in the seventh embodiment, and Figure 18(D) is a cross-sectional view taken along the line K2-K2 in Figure 18(C).

[0239] In the modified example's reinforcement retention step S43, instead of leaving the second regions 23b and 29b as uncut regions, relatively shallow second machined grooves 35 are formed in the second regions 23b and 29b, thereby leaving the second regions 23b and 29b as reinforced areas.

[0240] As described above, the second machining groove 35 has a second depth 21e that is less than or equal to half of the first depth 21d. In this modified example as well, the number of times the index feed process S27 is performed may be two or more, and is not particularly limited.

[0241] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the object of the present invention. Instead of, or in conjunction with, suction holding the lower surface 21b of the dress board 21 with the sub-chuck table 18, the sub-chuck table 18 may have a clamping mechanism, a pressing mechanism, etc. (none of which are shown) that presses the upper surface 21a of the dress board 21 against the dress board 21.

[0242] In any case, during the holding process S10, the dress board 21 can be held by the sub-chuck table 18 while the lower surface 21b of the dress board 21 is in contact with the holding surface 18a of the sub-chuck table 18.

[0243] Furthermore, in the embodiments and modifications described above, the cutting blade 46 is moved along the Y-axis and the sub-chuck table 18 is moved along the X-axis, but the direction of movement is not limited to these, as long as relative movement of the two in the XY plane can be achieved.

[0244] Furthermore, in the first machining groove forming steps S31 and S41 of the fifth embodiment and its modified form (see Figures 16(A) to 16(D)), the sixth embodiment and its modified form (see Figures 17(A) to 17(F)), and the seventh embodiment and its modified form (see Figures 18(A) to 18(D)), the cutting blade 46 is not limited to cutting downwards from the upper surface 21a of the dress board 21 by moving the cutting blade 46 downwards.

[0245] In the fifth to seventh embodiments and their variations, instead of moving the cutting blade 46 downward, the cutting blade 46 may be moved relatively in the first direction 21a3 from the outside of one side 21a1 in the first direction 21a3 to cut into the dress board 21. [Explanation of Symbols]

[0246] 2: Cutting device, 4: Base, 4a, 4b, 4c: Opening 6: Cassette elevator, 8: Cassette, 12: Table cover, 14: Cover component 11: Workpiece, 13: Dicing tape, 15: Annular frame 16: Chuck table, 16a: Holding surface, 16b: Clamping unit 17: Workpiece Unit 18: Sub-chuck table (holding table), 18a: Holding surface, 20: Support structure 21: Dress board, 21a: Top surface (first surface), 21b: Bottom surface (second surface) 21a1: one side, 21a2: the other side, 21a3: the first direction, 21a4: the second direction 21c: thickness direction, 21d: first depth, 21e: second depth 22: Cutting unit movement mechanism 23: First elongated region, 23a: First region, 23b, 23b1, 23b2: Second region 24: Guide rail, 26: Moving plate, 28: Screw shaft 25: First machining groove, 27: Index feed amount 29: Second elongated region, 29a: First region, 29b, 29b1, 29b2: Second region 30: Motor, 32: Guide rail, 34: Moving plate, 36: Screw shaft, 38: Motor 33: Length, 35: Second machining groove 40: Cutting unit, 42: Spindle housing, 44: Spindle 41: First group of narrow groove regions, 43: Second group of narrow groove regions 46: Cutting blade, 46a: Central opening, 46b: Lower end 48: Male thread, 50: Blade mount, 50a: Boss part, 52: Fixing nut 54: Microscope camera unit, 56: Spinner cleaning unit, 58: Controller S10: Holding process S20: Moving process S21, S25, S33, S43: Reinforcement remaining process S22,S34: Lowering process S23, S31, S35, S41: First processing groove forming process S24, S32, S42: Ascent process S26, S36, S44: Judgment process S27, S37, S45: Index feeding process

Claims

1. A method for processing a cutting blade, comprising performing at least one of dressing and truing on the cutting blade using a plate-shaped dressing board, A holding step in which the dress board is held by the holding table while the first surface of the dress board into which the cutting blade is cut and the second surface of the dress board located on the opposite side in the thickness direction from the first surface of the dress board are in contact with the holding surface of the holding table, A moving step of moving the cutting blade, which rotates around the spindle, and the holding table, which holds the dress board, relative to each other along a first direction along the first surface, Equipped with, The transfer process is, A first machining groove forming step is performed in which a first machining groove having a first depth is formed in a first region on a first elongated region of the first surface that is aligned with the first direction, A reinforcing portion retention step is performed by not forming a machining groove in a second region of the first surface on the first elongated region that is different from the first region, or by forming a second machining groove having a second depth of half or less of the first depth in the second region on the first elongated region, thereby leaving the second region as a reinforcing portion. A method for processing a cutting blade, characterized by having the following:

2. The method for machining a cutting blade according to claim 1, characterized in that, in the reinforcing portion retention step, the second region is located in the outer peripheral region including the outer peripheral edge of the dress board on the first elongated region along the first direction.

3. The method for machining a cutting blade according to claim 1, characterized in that, in the reinforcing portion remaining step, the second region is located in the central region of the dressing board, which is separated from the outer peripheral edge of the dressing board on the first elongated region along the first direction.

4. The transfer process is, An index feeding step of moving the cutting blade and the dressing board relative to each other such that, in the first surface, the cutting blade is located on the second elongated region which is perpendicular to the first direction and is separated from the first elongated region by a predetermined index feed amount in the second direction which is perpendicular to the first direction, and the cutting blade is located on the second elongated region which is aligned with the first direction, An additional first machining groove forming step, in which an additional first machining groove having the first depth is formed in the first region on the second elongated region, An additional reinforcing portion retention step is performed by not forming a machining groove in the second region of the first surface on the second elongated region, which is different from the first region, or by forming an additional second machining groove in the second region on the second elongated region, which has a second depth of half or less of the first depth, thereby leaving the second region as a reinforcing portion. A method for machining a cutting blade according to any one of claims 1 to 3, further comprising the above.

5. The cutting blade machining method according to claim 4, characterized in that, after the additional reinforcement remaining step, two or more of the second regions are adjacent in the second direction, and the total length from end to end of the two or more adjacent second regions in the second direction is at least twice the index feed amount.

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