Processing apparatus and dressing method

Abstract

To provide a processing device that enables the economical use of dresser boards. [Solution] The processing apparatus includes a holding means for holding the dresser board 12, a cutting means that rotatably supports a rotating shaft on which a cutting blade 26 is mounted, an X-axis moving means for moving the holding means in the X-axis direction, a Y-axis moving means for moving the cutting means in the Y-axis direction, a Z-axis moving means for moving the cutting means in the Z-axis direction, and a control means. The control means calculates the width of the cut formed in the dresser board 12 from the outer diameter (d) of the cutting blade 26 and the amount of cut (t) into the dresser board 12 as ω = 2(dt-t 2 ) 1 / 2 The calculated (ω) is used as the basis to set the index amount (Xi) of the cutting blade 26 in the X-axis direction relative to the dresser board 12.

Description

[Technical Field]

[0001] The present invention relates to a processing apparatus and a dressing method. [Background technology]

[0002] A wafer, on which multiple devices such as ICs and LSIs are divided by planned division lines and formed on its surface, is then ground on the back surface by a grinding machine to form the desired thickness. After that, it is divided into individual device chips by a dicing machine, laser processing machine, etc., and the divided device chips are used in electrical equipment such as mobile phones and personal computers.

[0003] Since a chamfer is formed on the outer edge of the wafer, when the back surface of the wafer is ground to thin it, the chamfer becomes a sharp knife edge. Therefore, operators must exercise extra caution when handling the wafer. Furthermore, when the chamfer becomes a sharp knife edge, cracks are more likely to form from the outer edge of the wafer inward, increasing the risk of device damage. To address this, the applicant has proposed a technique to remove the chamfer beforehand to prevent the formation of a knife edge during grinding (see, for example, Patent Document 1).

[0004] This technology involves holding the back surface of a wafer with a holding table to expose the front surface, positioning a cutting blade formed to a thickness sufficient to remove the chamfer (for example, about 3 mm) around the outer circumference of the wafer, and then rotating the cutting blade while rotating the holding table to form an L-shaped groove deeper than the finished thickness of the wafer, thereby removing the chamfer. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2013-211409 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Typically, the outer end face of a manufactured cutting blade is curved and lacks the flat surface necessary for a cutting blade that removes chamfered areas. Furthermore, the outer end face wears down with use, changing from a flat surface to a curved surface and tapering. If a portion of the chamfered area is removed using such a cutting blade, the inner angle between the outer side surface of the wafer and the remaining chamfered area will not be sharp, and there is a risk of knife edge formation on the outer edge of the wafer when the back surface of the wafer is ground. Therefore, the outer end face of the cutting blade is periodically or optionally dressed with a dresser board to restore a flat surface.

[0007] However, there is a problem in that the amount of indexing of the cutting blade relative to the dresser board varies from person to person, preventing the proper and economical use of the dresser board.

[0008] The object of the present invention is to provide a processing apparatus and a dressing method that enable the economical use of dresser boards. [Means for solving the problem]

[0009] According to the present invention, the following processing apparatus is provided that solves the above problems. That is, "A processing device for shaping the outer end surface of a cutting blade, The system includes a holding means for holding a dresser board, a cutting means that rotatably supports a rotating shaft to which a cutting blade is attached, an X-axis moving means for moving the holding means in the X-axis direction, a Y-axis moving means for moving the cutting means in the Y-axis direction perpendicular to the X-axis direction, a Z-axis moving means for moving the cutting means in the Z-axis direction perpendicular to both the X-axis and Y-axis directions, and a control means. The control means is, The outer diameter of the cutting blade (d) and the depth of cut into the dresser board (t) are used to determine the width of the cut formed in the dresser board (ω) as ω = 2(dt - t 2 ) 1 / 2A processing device is provided that calculates (ω) and sets the index amount of the cutting blade in the X-axis direction relative to the dresser board based on the calculated (ω).

[0010] The control means preferably sets the index amount to (ω) if the length of one side of the dresser board extending in the X-axis direction is an integer multiple of (ω), and sets the index amount to (ω) + (α / number of indices) if the length of one side of the dresser board extending in the X-axis direction is an integer multiple of (ω) plus the remainder (α).

[0011] Furthermore, the present invention provides the following dressing method that solves the above problems. That is, A dressing method for shaping the outer end face of a cutting blade, A preparation step for preparing a machining apparatus including a holding means for holding a dresser board, a cutting means that rotatably supports a rotating shaft on which a cutting blade is attached, an X-axis moving means for moving the holding means in the X-axis direction, a Y-axis moving means for moving the cutting means in the Y-axis direction perpendicular to the X-axis direction, and a Z-axis moving means for moving the cutting means in the Z-axis direction perpendicular to both the X-axis and Y-axis directions. Let (d) be the outer diameter of the cutting blade, (t) be the depth of cut into the dresser board, and (ω) be the width of the cut formed in the dresser board. Then ω = 2(dt - t) 2 ) 1 / 2 The calculation process for calculating (ω) by, A Y-axis positioning step involves positioning the outer peripheral end face of the cutting blade on one side of the dresser board held by the holding means that extends in the X-axis direction, in the Y-axis direction. A Z-axis positioning step in which the tip of the cutting blade is positioned at the cutting position in the Z-axis direction from the surface of the dresser board, A dressing step in which the cutting blade is moved in the Y-axis direction from one side of the dresser board extending in the X-axis direction to the other side of the dresser board extending in the X-axis direction by activating the Y-axis moving means, and the outer peripheral end face of the cutting blade is dressed to a flat surface, An indexing process for relatively index-feeding a cutting blade and a dresser board in the X-axis direction, and in the indexing process, a dressing method for setting an index amount based on (ω) calculated in the calculating process is provided.

[0012] When the length of one side of the dresser board extending in the X-axis direction is an integer multiple of (ω), the index amount is set to (ω). When the length of one side of the dresser board extending in the X-axis direction is an integer multiple of (ω) plus a remainder (α), it is desirable that the index amount be (ω)+(α / index number).

[0013] In the Z-axis positioning process, the Z-axis moving means is operated so that the cutting amount gradually becomes deeper to move the cutting blade in the Z-axis direction. In the dressing process, the Y-axis moving means is operated according to the cutting amount that gradually becomes deeper by the operation of the Z-axis moving means, and the cutting blade is moved in the Y-axis direction from one side of the dresser board extending in the X-axis direction to the other side of the dresser board extending in the X-axis direction, and finally the cutting width is set to (ω).

Effect of the Invention

[0014] The processing apparatus of the present invention is a processing apparatus for forming an outer peripheral end surface of a cutting blade, and includes holding means for holding a dresser board, cutting means for rotatably supporting a rotating shaft with a cutting blade mounted thereon, X-axis moving means for moving the holding means in the X-axis direction, Y-axis moving means for moving the cutting means in the Y-axis direction orthogonal to the X-axis direction, Z-axis moving means for moving the cutting means in the Z-axis direction orthogonal to the X-axis direction and the Y-axis direction, and control means. The control means is from the outer diameter (d) of the cutting blade and the cutting amount (t) with respect to the dresser board, the cutting width (ω) formed on the dresser board is ω = 2(dt - t 2 ) 1 / 2It is calculated, and based on the calculated (ω), the indexing amount in the X-axis direction of the cutting blade with respect to the dresser board is set, so that the dresser board can be used economically.

[0015] The dressing method of the present invention is A dressing method for forming the outer peripheral end face of a cutting blade, comprising holding means for holding a dresser board, cutting means for rotatably supporting a rotating shaft equipped with a cutting blade, X-axis moving means for moving the holding means in the X-axis direction, Y-axis moving means for moving the cutting means in the Y-axis direction orthogonal to the X-axis direction, and Z-axis moving means for moving the cutting means in the Z-axis direction orthogonal to the X-axis direction and the Y-axis direction, and a preparation step of preparing a processing apparatus including the above; Regarding the outer diameter of the cutting blade as (d), the cutting depth with respect to the dresser board as (t), and the cutting width formed on the dresser board as (ω), ω = 2(dt - t 2 ) 1 / 2 and a calculation step of calculating (ω) by the above formula; a Y-axis direction positioning step of positioning the outer peripheral end face of the cutting blade on one side extending in the X-axis direction of the dresser board held by the holding means in the Y-axis direction; a Z-axis direction positioning step of positioning the tip of the cutting blade at the cutting position in the Z-axis direction from the surface of the dresser board; a dressing step of operating the Y-axis moving means and moving the cutting blade in the Y-axis direction from one side of the dresser board extending in the X-axis direction to the other side of the dresser board extending in the X-axis direction to dress the outer peripheral end face of the cutting blade into a flat surface; and an indexing step of relatively indexing the cutting blade and the dresser board in the X-axis direction, wherein in the indexing step, the indexing amount is set based on (ω) calculated in the calculation step, so that the dresser board can be used economically.

Brief Description of the Drawings

[0016] [Figure 1]A perspective view of the processing apparatus according to the present invention. [Figure 2] A perspective view of the holding mechanism shown in Figure 1. [Figure 3] A perspective view of the cutting mechanism shown in Figure 1. [Figure 4] Figure 3 is a perspective view of the cutting mechanism with the blade cover disassembled. [Figure 5] (a) Perspective view of the cutting mechanism with the blade cover shown in Figure 3 removed, (b) Exploded perspective view of the cutting mechanism shown in (a). [Figure 6] A schematic diagram showing the calculation process. [Figure 7] A schematic diagram illustrating the indexing process. [Figure 8] A perspective view showing the Y-axis positioning process. [Figure 9] A perspective view showing the dressing process. [Modes for carrying out the invention]

[0017] Hereinafter, preferred embodiments of the processing apparatus according to the present invention will be described with reference to the drawings.

[0018] (Processing equipment 2) As shown in Figure 1, the processing apparatus 2 includes a holding means 4 for holding a dresser board, a cutting means 6 that rotatably supports a rotating shaft on which a cutting blade is mounted, an X-axis moving means (not shown) for moving the holding means 4 in the X-axis direction, a Y-axis moving means (not shown) for moving the cutting means 6 in the Y-axis direction perpendicular to the X-axis direction, a Z-axis moving means (not shown) for moving the cutting means 6 in the Z-axis direction perpendicular to both the X-axis and Y-axis directions, and a control means 8 for controlling the operation of the processing apparatus 2. The X, Y, and Z axis directions are indicated by arrows X, Y, and Z in Figure 1, respectively. The XY plane defined by the X-axis and Y-axis directions is substantially horizontal.

[0019] (Holding means 4 of processing device 2) As shown in Figure 2, the holding means 4 includes a rectangular dresser board holding table 10. A suction groove 10a is formed on the upper surface of the dresser board holding table 10, and the suction groove 10a is connected to a suction means (not shown). The dresser board holding table 10 uses the suction means to generate suction force in the suction groove 10a, and holds the rectangular dresser board 12 placed on the upper surface of the dresser board holding table 10 by suction. The dresser board 12 can be formed by mixing abrasive grains such as white alundum or green carbon into a bonding material such as vitrified bond or resin bond. The dimensions of the dresser board 12 may be, for example, 75 mm in length in the X-axis direction, 125 mm in length in the Y-axis direction, and 1 mm in thickness.

[0020] The holding means 4 further includes an X-axis movable member 14 that is movable in the X-axis direction, a bracket 16 that connects the X-axis movable member 14 and the dresser board holding table 10, and a workpiece holding table 18 supported by the X-axis movable member 14. A disc-shaped suction chuck 20 is positioned at the upper end of the workpiece holding table 18. The suction chuck 20 is made of a porous material such as porous ceramics and is connected to a suction means (not shown). The workpiece holding table 18 generates a suction force on the upper surface of the suction chuck 20 using the suction means and holds a workpiece such as a semiconductor wafer placed on the upper surface of the workpiece holding table 18 by suction.

[0021] (Cutting means 6 of processing device 2) As shown in Figures 3 and 4, the cutting means 6 comprises a rotating shaft housing 22, a rotating shaft 24 rotatably supported by the rotating shaft housing 22, an annular cutting blade 26 fixed to the rotating shaft 24, and a motor (not shown) for rotating the rotating shaft.

[0022] A blade cover 28 is attached to the tip of the rotating shaft housing 22. The blade cover 28 has a fixed part 28a fixed to the tip of the rotating shaft housing 22, a first detachable part 28b detachably attached to the tip of the fixed part 28a via a screw 30, and a second detachable part 28c detachably attached to the upper part of the fixed part 28a via a screw 32. The fixed part 28a and the first detachable part 28b are equipped with cutting fluid nozzles 34 that supply cutting fluid to the cutting blade 26 and the workpiece.

[0023] Referring to Figures 5(a) and 5(b), an annular mounting flange 24a protruding radially outward is provided on the outer circumferential surface of the tip side of the rotating shaft 24. A male thread 24b is formed on the outer circumferential surface of the rotating shaft 24 further towards the tip than the mounting flange 24a. First, a cutting blade 26 is mounted on the tip of the rotating shaft 24, then an annular detachable flange 36 is mounted, and finally a nut 38 is fitted onto the male thread 24b of the rotating shaft 24. In this way, the cutting blade 26 is sandwiched from both sides in the Y-axis direction by the mounting flange 24a and the detachable flange 36 of the rotating shaft 24, and the cutting blade 26 is fixed to the tip of the rotating shaft 24. When the rotating shaft 24 is rotated by the motor with the Y-axis direction as its axis, the cutting blade 26 rotates together with the rotating shaft 24. The cutting blade 26 is formed by fixing abrasive grains such as diamond with a binder such as resin bond or metal bond. The thickness of the cutting blade 26 can be arbitrarily selected depending on the processing requirements, but in the case of removing a portion of the chamfered part of the wafer, a cutting blade 26 with a thickness of about 3 mm may be used.

[0024] (X-axis moving means of processing device 2) Although not shown, the X-axis moving means includes a ball screw connected to the X-axis movable member 14 of the holding means 4 and extending in the X-axis direction, and a motor for rotating the ball screw. The X-axis moving means converts the rotational motion of the motor into a linear motion by the ball screw and transmits it to the X-axis movable member 14 of the holding means 4 to move the X-axis movable member 14 in the X-axis direction. As a result, the dresser board holding table 10 and the workpiece holding table 18 move in the X-axis direction.

[0025] (Y-axis moving means of the processing apparatus 2) The Y-axis moving means includes a ball screw connected to the rotary shaft housing 22 of the cutting means 6 and extending in the Y-axis direction, and a motor for rotating the ball screw. The Y-axis moving means converts the rotational motion of the motor into a linear motion by the ball screw and transmits it to the rotary shaft housing 22 to move the rotary shaft housing 22 in the Y-axis direction. As a result, the cutting blade 26 moves in the Y-axis direction.

[0026] (Z-axis moving means of the processing apparatus 2) The Z-axis moving means includes a ball screw connected to the rotary shaft housing 22 of the cutting means 6 and extending in the Z-axis direction, and a motor for rotating the ball screw. The Z-axis moving means converts the rotational motion of the motor into a linear motion by the ball screw and transmits it to the rotary shaft housing 22 to move the rotary shaft housing 22 in the Z-axis direction. As a result, the cutting blade 26 moves in the Z-axis direction.

[0027] (Control means 8 of the processing apparatus 2) The control means 8 is composed of a computer having a processor and a memory. The control means 8 calculates the cutting width (ω) formed on the dresser board 12 from the outer diameter (d) of the cutting blade 26 and the cutting amount (t) with respect to the dresser board 12 as ω = 2(dt - t 2 ) 1 / 2 As is clear from referring to FIG. 6, the relationship among the outer diameter (d) of the cutting blade 26, the cutting amount (t) with respect to the dresser board 12, and the cutting width (ω) formed on the dresser board 12 can be expressed as in the following formula 1 from the Pythagorean theorem. Equation 1 (d / 2) 2 =((d / 2)-t) 2 +(ω / 2) 2 From equation 1 above, the cutting width (ω) can be expressed as shown in equation 2 below. Equation 2 ω = 2(dt - t 2 ) 1 / 2

[0028] The control means 8 sets the index amount (Xi) of the cutting blade 26 in the X-axis direction relative to the dresser board 12, based on the calculated (ω). The control means 8 sets the index amount (Xi) to (ω) (Xi=ω) if the length of one side of the dresser board 12 extending in the X-axis direction is an integer multiple of (ω), and sets the index amount (Xi) to (ω) + (α / number of indices) if the length of one side of the dresser board 12 extending in the X-axis direction is an integer multiple of (ω) + remainder (α), as shown in Figure 7. In this way, the control means 8 sets the index amount (Xi) in the X-axis direction based on the cutting width (ω), making it possible to use the dresser board 12 economically. Note that in Figures 6 and 7, the center of the cutting blade 26 is indicated by the symbol c.

[0029] As shown in Figure 1, the processing apparatus 2 further includes a vertically movable cassette stand 42 on which a cassette 40 containing multiple workpieces is placed, an loading / unloading means 46 for pulling out workpieces before cutting from the cassette 40 and transporting them to a temporary storage table 44, and for transporting workpieces after cutting that are positioned on the temporary storage table 44 into the cassette 40, a first transport means 48 for transporting the workpieces before cutting that have been transported from the cassette 40 to the temporary storage table 44 to the workpiece holding table 18, an imaging means 50 for imaging the workpieces held on the workpiece holding table 18, a cleaning means 52 for cleaning the workpieces after cutting, and a second transport means 54 for transporting the workpieces after cutting from the workpiece holding table 18 to the cleaning means 52.

[0030] (Dressing method) Next, preferred embodiments of the dressing method according to the present invention will be described.

[0031] (preparation process) In this embodiment, first, a preparation step is performed to prepare a processing apparatus that includes a holding means for holding a dresser board, a cutting means that rotatably supports a rotating shaft on which a cutting blade is attached, an X-axis moving means for moving the holding means in the X-axis direction, a Y-axis moving means for moving the cutting means in the Y-axis direction which is perpendicular to the X-axis direction, and a Z-axis moving means for moving the cutting means in the Z-axis direction which is perpendicular to both the X-axis and Y-axis directions. The processing apparatus prepared in the preparation step may be the processing apparatus 2 described above.

[0032] (calculation process) After performing the preparation steps, let (d) be the outer diameter of the cutting blade 26, (t) be the depth of cut into the dresser board 12, and (ω) be the width of the cut formed in the dresser board 12. Then ω = 2(dt-t 2 ) 1 / 2 The calculation process for determining (ω) is carried out by the control means 8.

[0033] In the calculation process, the outer diameter (d) of the cutting blade 26 and the depth of cut (t) of the dresser board 12 are input to the control means 8. For example, if the outer diameter (d) of the cutting blade 26 is 58 mm and the depth of cut (t) of the dresser board 12 is 0.43 mm, then the cutting width (ω) is: ω = 2 × (58 × 0.43 - 0.43) 2 ) 1 / 2 = 9.95mm This is the result.

[0034] (Y-axis positioning process) After the calculation process is performed, a Y-axis positioning process is carried out in which the outer peripheral end face of the cutting blade 26 is positioned in the Y-axis direction on one side of the dresser board 12 held by the holding means 4 that extends in the X-axis direction (see Figure 8).

[0035] (Z-axis positioning process) After performing the Y-axis positioning process, a Z-axis positioning process is performed to position the tip of the cutting blade 26 at the cutting position in the Z-axis direction from the surface of the dresser board 12. In the Z-axis positioning process, the cutting blade 26 is first rotated in the direction indicated by arrow R in Figure 8. Then, while supplying cutting fluid from the cutting fluid nozzle 34 to the part of the cutting blade 26 tip that will make the cut, the Z-axis moving mechanism is activated to make the tip of the cutting blade 26 cut into the surface of the dresser board 12 and position it at the cutting position in the Z-axis direction.

[0036] (Dressing process) After performing the Z-axis positioning process, as shown in Figure 9, the Y-axis moving means is activated to move the cutting blade 26 in the Y-axis direction from one side of the dresser board 12 extending in the X-axis direction to the other side of the dresser board 12 extending in the X-axis direction, thereby performing a dressing process to flatten the outer peripheral end face of the cutting blade 26. In Figure 9, the notched groove formed on the surface of the dresser board 12 as a result of the dressing process is indicated by reference numeral 56.

[0037] Such a dressing process can be performed multiple times in the same cutting groove 56. That is, in the Z-axis positioning process, the Z-axis moving means is operated to move the cutting blade 26 in the Z-axis direction so that the depth of cut gradually increases, and in the dressing process, the Y-axis moving means is operated in accordance with the depth of cut which gradually increases due to the operation of the Z-axis moving means, and the cutting blade 26 is moved in the Y-axis direction from one side of the dresser board 12 extending in the X-axis direction to the other side of the dresser board 12 extending in the X-axis direction, so that the final depth of cut is (ω). For example, the dressing process can be divided into first, second, and third steps, and the Z-axis index amount and the number of dressings in each step can be set as follows. Z-axis index amount, number of dressings Step 1: 0.015mm, 20 times Second step: 0.005mm, 20 times Third step: 0.002 mm, 15 times In the above example, the final depth of cut in the Z-axis direction is: 0.015×20+0.005×20+0.002×15=0.43mm That is the case.

[0038] (Indexing process) After the dressing process, an indexing process is performed in which the cutting blade 26 and the dresser board 12 are relatively indexed in the X-axis direction (see Figure 7). In the indexing process, the index amount (Xi) in the X-axis direction is set based on (ω) calculated in the calculation process. Specifically, if the length of one side of the dresser board 12 extending in the X-axis direction is an integer multiple of (ω), the index amount (Xi) is set to (ω). If the length of one side of the dresser board 12 extending in the X-axis direction is an integer multiple of (ω) + remainder (α), the index amount (Xi) is set to (ω) + (α / number of indices). For example, if the cutting width (ω) is 9.95 mm and the length of one side of the dresser board 12 extending in the X-axis direction is 75 mm, the number of indices is 7, so the remainder (α) is α = 75 - (9.95 × 7) = 5.35 mm Therefore, the index amount (Xi) is, Xi = 9.95 + 5.35 / 7 = 10.7mm This is the result.

[0039] As described above, in this embodiment, the cutting width (ω) formed in the dresser board 12 is calculated from the outer diameter (d) of the cutting blade 26 and the amount of cutting (t) into the dresser board 12 as ω = 2(dt - t 2 ) 1 / 2 The calculated (ω) is used as the basis to set the index amount (Xi) of the cutting blade 26 in the X-axis direction relative to the dresser board 12, thereby enabling economical use of the dresser board 12.

[0040] Furthermore, when separating a package substrate called a QFN (Quad Flat Non-leaded package) into individual devices, the wiring boards stacked on the surface are cut for each individual device using a cutting blade. However, the use of the cutting blade causes wear on the outer edge surface, changing from a flat surface to a curved surface and resulting in a tapered shape. Using such a cutting blade prevents the package substrate from being cut with a sharp inner angle, which can lead to burrs and short circuits. However, in this embodiment, dressing is performed automatically with an appropriate and economical index amount, thus eliminating the problem of individual differences in the index amount of the cutting blade on the dresser board among operators, which prevents the proper and economical use of the dresser board. [Explanation of Symbols]

[0041] 2: Processing equipment 4: Holding means 6:Cutting means 8: Control means 12: Dresser board 24: Rotation axis 26: Cutting blade d: Outer diameter of the cutting blade ω: Cut width t: Amount of cut Xi: Index amount

Claims

1. A processing apparatus for shaping the outer end surface of a cutting blade, The system includes a holding means for holding a dresser board, a cutting means that rotatably supports a rotating shaft to which a cutting blade is attached, an X-axis moving means for moving the holding means in the X-axis direction, a Y-axis moving means for moving the cutting means in the Y-axis direction perpendicular to the X-axis direction, a Z-axis moving means for moving the cutting means in the Z-axis direction perpendicular to both the X-axis and Y-axis directions, and a control means. The control means is, The outer diameter of the cutting blade (d) and the depth of cut into the dresser board (t) are used to determine the width of the cut formed in the dresser board (ω) as ω = 2(dt - t) ２ ) １／２ A machining device that calculates (ω) and sets the index amount of the cutting blade in the X-axis direction relative to the dresser board based on the calculated (ω).

2. The control means is, If the length of one side of a dresser board extending in the X-axis direction is an integer multiple of (ω), then the index quantity is (ω). The processing apparatus according to claim 1, wherein if the length of one side of a dresser board extending in the X-axis direction is an integer multiple of (ω) plus the remainder (α), the index amount is (ω) + (α / number of indices).

3. A dressing method for shaping the outer end face of a cutting blade, A preparation step for preparing a machining apparatus including a holding means for holding a dresser board, a cutting means that rotatably supports a rotating shaft on which a cutting blade is attached, an X-axis moving means for moving the holding means in the X-axis direction, a Y-axis moving means for moving the cutting means in the Y-axis direction perpendicular to the X-axis direction, and a Z-axis moving means for moving the cutting means in the Z-axis direction perpendicular to both the X-axis and Y-axis directions. Let (d) be the outer diameter of the cutting blade, (t) be the depth of cut into the dresser board, and (ω) be the width of the cut formed in the dresser board. Then ω = 2(dt - t) ２ ) １／２ The calculation process for calculating (ω) by, A Y-axis positioning step in which the outer peripheral end face of the cutting blade is positioned in the Y-axis direction on one side of the dresser board held by the holding means that extends in the X-axis direction, A Z-axis positioning step in which the tip of the cutting blade is positioned at the cutting position in the Z-axis direction from the surface of the dresser board, A dressing step in which the cutting blade is moved in the Y-axis direction from one side of the dresser board extending in the X-axis direction to the other side of the dresser board extending in the X-axis direction by operating the Y-axis moving means, thereby dressing the outer peripheral end face of the cutting blade into a flat surface, The process includes an indexing step in which the cutting blade and the dresser board are relatively indexed and fed in the X-axis direction, A dressing method in which the index amount is set based on (ω) calculated in the calculation step in the index step.

4. If the length of one side of a dresser board extending in the X-axis direction is an integer multiple of (ω), then the index quantity is (ω). The dressing method according to claim 3, wherein if the length of one side of a dresser board extending in the X-axis direction is an integer multiple of (ω) plus the remainder (α), the index amount is (ω) + (α / number of indices).

5. In the Z-axis positioning step, the Z-axis moving means is operated to move the cutting blade in the Z-axis direction so that the depth of cut gradually increases. The dressing method according to claim 3, wherein in the dressing process, the Y-axis moving means is operated in accordance with the amount of cut that gradually deepens due to the operation of the Z-axis moving means, and the cutting blade is moved in the Y-axis direction from one side of the dresser board extending in the X-axis direction to the other side of the dresser board extending in the X-axis direction, and the final cut width is (ω).

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