Edge trimming method and edge trimming apparatus

Abstract

To increase productivity by suppressing the frequency of dressing of a cutting blade.SOLUTION: A method of forming a ring-shaped processing groove Wa on an outer peripheral edge of a wafer W by cutting a cutting blade 35 into an outer peripheral portion of the wafer W and rotating the wafer W and the cutting blade 35 comprises: a groove forming step of cutting the cutting blade 35 into the wafer W to a predetermined depth to form the ring-shaped processing groove Wa on the outer peripheral edge of the wafer W in a state of positioning one side surface 35a of the cutting blade 35 radially inward of the outer peripheral edge of the wafer W, and positioning the other side surface 35b of the cutting blade 35 radially outward and upward of the outer peripheral edge of the wafer W; and a corner correcting step of correcting to a right angle a corner portion between a side surface Wa1 and a bottom surface Wa2 of the processing groove Wa by cutting the processing groove Wa while bringing the other side surface 35b and an outer peripheral surface 35c of the cutting blade 35 into contact with the side surface Wa1 and the bottom surface Wa2 of the processing groove Wa formed in the groove forming step.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an edge trimming method and an edge trimming device for forming a ring-shaped groove by trimming the outer periphery (edge ​​portion) of a wafer. [Background technology]

[0002] For example, in the manufacturing process of semiconductor chips, the surface of a disk-shaped semiconductor wafer (hereinafter simply referred to as a "wafer") is divided into a large number of rectangular areas by planned division lines called streets that are arranged in a grid pattern, and devices such as ICs and LSIs are formed in each rectangular area. Then, the wafer on which a large number of devices are formed is cut along the planned division lines with a cutting blade of a cutting machine called a dicer, thereby obtaining a plurality of semiconductor chips.

[0003] Semiconductor chips are used in various electronic devices, such as personal computers (PCs) and mobile phones (smartphones). To meet the recent demand for thinner and more compact electronic devices, wafers are being ground to a thinner finish. Wafers ground to a thinner finish are chamfered (R-chamfered) on their periphery to prevent cracking and dust generation during the manufacturing process, as shown in Figure 5(a). Therefore, when a wafer W with a chamfered periphery, as shown in Figure 5(a), is ground thinner, the chamfered portion R on the periphery becomes sharp, as shown in Figure 5(b), resulting in chipping and damage to the wafer W. Furthermore, when a wafer W with a thickness t0 shown in Figure 5(a) is ground with a grinding allowance Δt as shown in Figure 5(b), the wafer W is finished to a thickness t1 with a sharply pointed periphery.

[0004] Therefore, as shown in Fig. 6(a), a cutting blade (not shown) is used to cut into the chamfered portion R on the outer periphery of the wafer W to form a ring-shaped groove Wa of a predetermined width B and a predetermined depth h by trimming (edge ​​trimming), and then the back surface of the wafer W (the surface opposite to the surface on which the groove Wa is formed) is ground to simultaneously remove the groove Wa as shown in Fig. 6(b) (see Patent Document 1). Note that when the surface opposite to the groove Wa of a wafer W having a thickness t0 shown in Fig. 6(a) and a groove Wa of width B and depth h formed on the outer periphery (the bottom surface in Fig. 6(a)) is ground with a grinding allowance Δt, the wafer W is finished to a thickness t2 from which the chamfered portion R and the groove Wa have been removed, as shown in Fig. 6(b). In this case, if the thickness of the portion of the wafer W before grinding excluding the machining groove Wa on the outer periphery shown in Figure 6(a) is t2 (=t0-h), the grinding allowance Δt of the wafer W is set to be larger than the thickness t2 (Δt>t2).

[0005] However, when a machining groove is formed on the outer edge of a wafer by edge trimming with a cutting blade, the corners of the cutting blade gradually wear and become rounded. Therefore, Patent Document 2 proposes a method for determining whether the shape of the cutting surface in the width direction of the cutting blade is good or bad, and Patent Document 3 proposes a method for dressing a worn cutting blade to correct the corners of the cutting blade to a right angle and prevent unnecessary cuts. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-245167 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-076483 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-069277 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the methods proposed in Patent Documents 3 and 4 have the problem that inspecting the wear of the grinding blade and dressing it require time and effort, which leads to a decrease in productivity.

[0008] The present invention has been made in consideration of the above problems, and its object is to provide an edge trimming method and an edge trimming device that can reduce the frequency of dressing of the cutting blade and increase productivity. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the edge trimming method of the present invention is a method of cutting a cutting blade into the outer peripheral portion of a wafer held on a chuck table and forming a ring-shaped machining groove on the outer peripheral edge of the wafer while rotating the wafer and the cutting blade, characterized by including: a groove forming process in which one side of the cutting blade is positioned radially inward from the outer peripheral edge of the wafer and the other side of the cutting blade is positioned radially outward and above the outer peripheral edge of the wafer, and the cutting blade is then cut into the wafer to a predetermined depth to form a ring-shaped machining groove on the outer peripheral edge of the wafer; and a corner correction process in which the other side and outer peripheral surface of the cutting blade are brought into contact with the side and bottom surfaces of the machining groove formed in the groove forming process, respectively, to cut the machining groove, thereby correcting the corner between the side and bottom surface of the machining groove to a right angle.

[0010] Further, an edge trimming device according to the present invention is a device comprising: a chuck table for holding a wafer; a processing mechanism for cutting the outer periphery of the wafer by rotating a cutting blade attached to the tip of a spindle; a Z-axis movement mechanism for relatively moving the chuck table and the processing mechanism in the cutting feed direction of the cutting blade; a rotation mechanism for relatively moving the chuck table and the processing mechanism in a circumferential direction about the center of the wafer held on the chuck table; a Y-axis movement mechanism for relatively moving the chuck table and the processing mechanism in the axial direction of the spindle; and a control unit, wherein the control unit is configured to The cutting blade is positioned with one side thereof radially inward from the outer peripheral edge and the other side thereof radially outward from and above the outer peripheral edge of the wafer, and the cutting blade is caused to cut into the wafer to a predetermined depth, and the wafer is rotated by the rotation mechanism, thereby forming a ring-shaped groove on the outer peripheral edge of the wafer; and a second control unit is configured to move the cutting blade away from the wafer, and then to cut the groove by bringing the other side and outer peripheral surface of the cutting blade into contact with the side and bottom surfaces of the groove, respectively, thereby correcting the corner between the side and bottom surfaces of the groove to a right angle. Edge Tri [Effects of the Invention]

[0011] According to the present invention, a machining groove of a predetermined width and depth is formed on the outer edge of the wafer by cutting (trimming) using one surface and the outer peripheral surface of the cutting blade, and the corners between the side and bottom surfaces of the machining groove are corrected to right angles by cutting using the other surface and the outer peripheral surface of the cutting blade.In other words, one surface and the other surface of the cutting blade are used to form the machining groove and to correct the corners of the machining groove, respectively.This has the effect of reducing the frequency of dressing due to wear on the cutting blade and increasing productivity. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view of an edge trimming device according to the present invention; [Figure 2] 1 is a longitudinal sectional view of a main part of an edge trimming device showing a groove forming step in an edge trimming method according to the present invention. FIG. [Figure 3] 1 is a vertical cross-sectional view of a main part of an edge trimming device showing a corner correction step in an edge trimming method according to the present invention. FIG. [Figure 4] FIG. 4 is an enlarged detailed view of part A in FIG. 3. [Figure 5] 1A is a partial cross-sectional side view showing the chamfered portion of the outer periphery of the wafer, and FIG. 1B is a cross-sectional side view of the outer periphery of the wafer after grinding. [Figure 6] 1A is a partial cross-sectional side view showing the processed grooves on the outer periphery of the wafer, and FIG. 1B is a cross-sectional side view of the outer periphery of the wafer after grinding. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0014] [Edge trimming device configuration] First, the configuration of an edge trimming device 1 according to the present invention will be described below with reference to Figures 1 to 3. In the following description, as shown by the arrows in Figures 1 to 3, the "front-rear" direction is defined as the X-axis direction, the "left-right" direction is defined as the Y-axis direction, and the "up-down" direction is defined as the Z-axis direction.

[0015] FIG. 1 is a perspective view of an edge trimming device 1. The illustrated edge trimming device 1 has a base 2 that supports each component, and a gate-type column 3 is vertically erected at the rear end (-X axis direction end) of this base 2.

[0016] The edge trimming apparatus 1 includes, as its main components, a chuck table 10 that holds and rotates a thin, disk-shaped wafer W, a rotation mechanism 20 that rotates the chuck table 10 about a vertical central axis, a processing mechanism 30 that cuts the outer periphery of the wafer W held on the chuck table 10, an X-axis movement mechanism 40 that reciprocates the chuck table 10 together with the wafer W along the X-axis direction, a Z-axis movement mechanism 50 that raises and lowers the processing mechanism 30 along the Z-axis direction (the incision feed direction), a Y-axis movement mechanism 60 that reciprocates the processing mechanism 30 along the Y-axis direction (the indexing feed direction), and a control unit 70 that controls the operation of the various components. The following describes the configurations of the main components of the edge trimming apparatus 1: the chuck table 10, the rotation mechanism 20, the processing mechanism 30, the X-axis movement mechanism 40, the Z-axis movement mechanism 50, the Y-axis movement mechanism 60, and the control unit 70.

[0017] (Chuck table) The chuck table 10 is a disk-shaped member rotatably disposed in the approximate center of the base 2, and its upper surface constitutes a holding surface that suction-holds the wafer W. A ring-shaped suction groove 11 opens on the outer periphery of the holding surface of the chuck table 10, and this suction groove 11 is connected to a suction path 12 that is formed vertically at one location on the outer periphery of the chuck table 10, as shown in FIGS.

[0018] One end of a pipe 14 is connected to the suction path 12 via a rotary joint 13, and the other end of the pipe 14 is connected to a suction source 15 such as a vacuum pump or an ejector via an on-off valve V. Therefore, the suction groove 11 opening on the upper surface of the chuck table 10 is selectively connected to the suction source 15 by opening and closing the on-off valve V. The on-off valve V is electrically connected to a control unit 70, and its opening and closing operation is controlled by the control unit 70.

[0019] In addition, the chuck table 10 is rotatably supported by a cylindrical support 16 disposed below it via a bearing 17, and the support 16 is erected vertically on a slider 42 of an X-axis movement mechanism 40 described below.

[0020] Here, the wafer W held on the holding surface of the chuck table 10 is, for example, a thin, disk-shaped member made of single-crystal silicon (Si), and its outer periphery is chamfered into a circular arc shape (R-chamfered) to prevent cracking and dust generation during the manufacturing process, as shown in Fig. 5(a). Although not shown, the surface of the wafer W (the upper surface in Figs. 2 and 3) is divided into a plurality of rectangular regions by mutually orthogonal grid-like dividing lines (streets), and devices such as ICs and LSIs are formed in each rectangular region.

[0021] (Rotation mechanism) The rotation mechanism 20 rotates the chuck table 10 together with the wafer W held thereon about the vertical central axis CL in the direction of the arrow in Figures 2 and 3 at a predetermined speed, and is housed inside the support column 16 that rotatably supports the chuck table 10. Although the details of this rotation mechanism 20 are not shown, it is equipped with a motor that serves as a rotation drive source, and this motor is electrically connected to the control unit 70, and its operation is controlled by the control unit 70.

[0022] (Processing mechanism) The processing mechanism 30 includes a spindle housing 31 attached to the lower part of a lifting plate 52 of a Z-axis movement mechanism 50 (described later), and an imaging unit 32. The imaging unit 32 captures an image of the wafer W held on the holding surface of the chuck table 10, and detects the positions of the planned dividing line (not shown) and the outer periphery of the wafer W.

[0023] The rectangular box-shaped spindle housing 31 houses a spindle motor 34 that rotates a spindle 33 (see FIGS. 2 and 3) that is arranged along the Y-axis direction, and a disk-shaped cutting blade 35, which is a processing tool, is attached to the tip of the spindle 33 that protrudes from the spindle housing 31. As shown in FIG. 2, the spindle motor 34 is electrically connected to a control unit 70, and its operation is controlled by the control unit 70.

[0024] (X-axis movement mechanism) The X-axis movement mechanism 40 is a mechanism for reciprocating the chuck table 10 together with the wafer W along the X-axis direction, and as shown in FIG. 1 , includes a pair of left and right X-axis guide rails 41 arranged in the center of the base 2, a rectangular plate-shaped slider 42 slidably installed in the X-axis direction along these X-axis guide rails 41, a reversible X-axis ball screw 43 arranged along the X-axis between the pair of left and right X-axis guide rails 41, and an X-axis servo motor 44 serving as a rotational drive source for rotating the X-axis ball screw 43 forward and backward. The chuck table 10 is supported on the slider 42 via support columns 16 so as to be rotatable about a vertical central axis CL. A nut member (not shown) protrudes downward from the center of the underside of the slider 42 in the width direction, and the X-axis ball screw 43 is threadedly inserted into the nut member.

[0025] Therefore, when the X-axis servo motor 44 is started to rotate the X-axis ball screw 43 forward or backward, the slider 42, from which a nut member (not shown) that screws onto the X-axis ball screw 43 protrudes, slides in the X-axis direction along the pair of left and right X-axis guide rails 41, and the chuck table 10 and the wafer W held thereon move back and forth together with the slider 42 and the rotation mechanism 20 in the X-axis direction.

[0026] (Z-axis movement mechanism) The Z-axis movement mechanism 50 is a mechanism for raising and lowering the machining mechanism 30 along the Z-axis direction, and is configured to include a pair of Z-axis guide rails 51 arranged parallel to each other vertically on the left and right sides of a rectangular plate-shaped slider 61, a lifting plate 52 that can move up and down along these Z-axis guide rails 51, a rotatable Z-axis ball screw 53 that is arranged vertically between the pair of Z-axis guide rails 51, and a reversible Z-axis servo motor 54 that rotates the Z-axis ball screw 53. The machining mechanism 30 is attached to the lower part of the lifting plate 52. A nut member (not shown) protrudes from the back surface of the lifting plate 52, and the Z-axis ball screw 53 is threadedly inserted into the nut member.

[0027] In the Z-axis moving mechanism 50 configured as described above, when the Z-axis servo motor 54 is started and the Z-axis ball screw 53 rotates forward and backward, the lifting plate 52, which has a protruding nut member (not shown) that screws onto the Z-axis ball screw 53, moves up and down along the pair of Z-axis guide rails 51, and the processing mechanism 30 attached to the lifting plate 52 also moves up and down along the Z-axis direction.

[0028] (Y-axis movement mechanism) The Y-axis movement mechanism 60 is a mechanism for reciprocating the processing mechanism 30 along the Y-axis direction (indexing feed direction), and is equipped with a slider 61. Here, the slider 61 is movable along the Y-axis direction along a pair of upper and lower Y-axis guide rails 62 that are arranged parallel to each other along the Y-axis direction in front of the gate-type column 3 that is erected vertically on the base 2.

[0029] The Y-axis movement mechanism 60 is provided with a Y-axis ball screw 63 that can rotate forward and backward and is arranged along the Y-axis between a pair of upper and lower Y-axis guide rails 62, and a nut member (not shown) that protrudes from the back surface of the slider 61 is threadedly engaged with the Y-axis ball screw 63. One axial end of the Y-axis ball screw 63 is connected to a Y-axis servo motor 64 that serves as a rotational drive source. The Y-axis servo motor 64 is electrically connected to the control unit 70, and its operation is controlled by the control unit 70.

[0030] Therefore, in the Y-axis movement mechanism 60, when the Y-axis servo motor 64 is started to rotate the Y-axis ball screw 63 forward or backward, the slider 61, from which a nut member (not shown) that screws onto the Y-axis ball screw 63 protrudes, can move in the Y-axis direction (indexing feed direction) along the Y-axis guide rail 62 together with the lifting plate 52. Therefore, the processing mechanism 30 attached to the lifting plate 52 can move in the Y-axis direction (indexing feed direction) along the Y-axis guide rail 62.

[0031] In conclusion, in the edge trimming apparatus 1 shown in FIG. 1, the chuck table 10 and the wafer W held thereon are movable along the X-axis direction, and the processing mechanism 30 is movable along the Y-axis direction and the Z-axis direction.

[0032] (Control unit) The control unit 70 includes a CPU (Central Processing Unit) that performs arithmetic processing according to a control program, and storage units such as a ROM (Read Only Memory) and a RAM (Random Access Memory). In particular, in this embodiment, the control unit 70 includes a first control unit 71 and a second control unit 72.

[0033] 2, the first control unit 71 positions one side surface (hereinafter referred to as the "outer surface") 35a of the cutting blade 35 radially inward from the outer peripheral edge of the wafer W and the other side surface (hereinafter referred to as the "inner surface") 35b of the cutting blade 35 radially outward from and above the outer peripheral edge of the wafer W, and then causes the cutting blade 35 to cut into the wafer W to a predetermined depth and rotates the wafer W using the rotation mechanism 20, thereby forming a ring-shaped groove Wa on the outer peripheral edge of the wafer W. Furthermore, the second control unit 72 moves the cutting blade 35 away from the wafer W, as shown in FIG. 3, and then brings the inner side surface 35b and outer peripheral surface 35c (see FIG. 4) of the cutting blade 35 into contact with the side surface Wa1 and bottom surface Wa2 (see FIG. 4) of the groove Wa, respectively, to cut the groove Wa, thereby correcting the corner between the side surface Wa1 and bottom surface Wa2 of the groove Wa to a right angle.

[0034] [Edge trimming method] Next, an edge trimming method according to the present invention, which is carried out in the edge trimming device 1 configured as above, will be described.

[0035] The edge trimming method according to the present invention is a method for forming a groove Wa of a predetermined width B and a predetermined depth h on the outer periphery of a wafer W by cutting (trimming) with a cutting blade 35. To form the groove Wa on the outer periphery of the top surface (the surface on which a device, not shown, is formed) of the wafer W by cutting with the cutting blade 35, first, the wafer W is placed on the holding surface of the chuck table 10, as shown in Figures 2 and 3. Then, the control unit 70 opens the on-off valve V, and the ring-shaped suction groove 11 opening on the holding surface of the chuck table 10 is connected to a suction source 15 via a suction path 12, a rotary joint 13, and a pipe 14.

[0036] As described above, when the ring-shaped suction groove 11 opening into the holding surface of the chuck table 10 is connected to the suction source 15, the suction groove 11 is evacuated by the suction source 15, and the wafer W held on the holding surface of the chuck table 10 is thereby suction-held on the holding surface. From this state, the chuck table 10 is moved along the X-axis direction by the X-axis movement mechanism 40 and positioned below the processing mechanism 30, and the imaging unit 32 of the processing mechanism 30 captures an image of the surface and outer periphery of the wafer W. When the position of the outer periphery of the wafer W is detected by this imaging, the first control unit 71 of the control unit 70 performs the groove forming process shown in FIG.

[0037] 2, the Y-axis moving mechanism 60 moves the processing mechanism 30 in the Y-axis direction above the wafer W, and positions the outer surface 35a of the cutting blade 35 radially inward by B (the same amount as the width of the processed groove) from the outer peripheral edge of the wafer W, and positions the inner surface 35b of the cutting blade 35 radially outward and above the outer peripheral edge of the wafer W. Then, from this state, the rotation mechanism 20 rotates the chuck table 10 and the wafer W held thereon around the central axis CL in the direction of the arrow at a predetermined speed, and the spindle motor 34 rotates the spindle 33 and the cutting blade 35 in the direction of the arrow at a predetermined speed.

[0038] As described above, when the wafer W and the cutting blade 35 are each rotating at a predetermined speed, the processing mechanism 30 is lowered by the Z-axis moving mechanism 50, and the cutting blade 35 is caused to cut into the wafer W to a predetermined depth h to cut the outer edge of the top surface of the wafer W, and a processed groove Wa of a predetermined width B and a predetermined depth h is formed on the outer edge of the top surface of the wafer W.

[0039] As described above, once the processed groove Wa is formed on the outer peripheral edge of the upper surface of the wafer W in the groove forming step, the second control unit 72 of the control unit 70 carries out the corner correcting step shown in FIG.

[0040] 3, the Z-axis moving mechanism 50 raises the processing mechanism 30, and the cutting blade 35 is moved away from the wafer W as shown by the chain line in Fig. 3. Then, the Y-axis moving mechanism 60 horizontally moves the processing mechanism 30 in the -Y-axis direction (the direction of the arrow in Fig. 3) so that the inner surface 35b of the cutting blade 35 is aligned with the side surface Wa1 of the groove Wa in the Y-axis direction. From this state, the rotation mechanism 20 rotates the chuck table 10 and the wafer W held thereon about the vertical central axis CL in the direction of the arrow, and the spindle motor 34 rotates the spindle 33 and the cutting blade 35 at a predetermined speed in the direction of the arrow. The Z-axis moving mechanism 50 lowers the processing mechanism 30, bringing the inner surface 35b and outer peripheral surface 35c of the cutting blade 35 into contact with the side surface Wa1 and bottom surface Wa2 of the groove Wa, respectively, to cut the groove Wa. As a result, the corner between the side surface Wa1 and the bottom surface Wa2 of the groove Wa is corrected to a right angle by the inner surface 35b and the outer peripheral surface 35c of the cutting blade 35.

[0041] As described above, according to the edge trimming method for wafers W of the present invention, a machining groove Wa of a predetermined width B and a predetermined depth h is formed on the outer edge of the upper surface of the wafer W by cutting (trimming) using the outer surface 35a and outer peripheral surface 35c of the cutting blade 35, and the corner portion between the side surface Wa1 and the bottom surface Wa2 of the machining groove Wa is corrected to a right angle by cutting using the inner surface 35b and outer peripheral surface 35c of the cutting blade 35.In other words, the outer surface 35a and inner surface 35b of the cutting blade 35 are used to form the machining groove Wa and to correct the corner portion of the machining groove Wa, respectively.This has the effect of reducing the frequency of dressing due to wear of the cutting blade 35 and increasing productivity.

[0042] The wafer W having the grooves Wa formed on the outer periphery of one surface is then ground by a grinding wheel of a grinding device until the entire surface of the other surface (the surface opposite to the surface on which the grooves Wa are formed) reaches a predetermined thickness, and the grooves Wa are removed by this grinding. Then, the wafer W ground to the predetermined thickness is divided into a plurality of chips by cutting along the planned division lines with a cutting blade 35.

[0043] In the above embodiment, a configuration is adopted in which the Z-axis moving mechanism 50 moves the processing mechanism 30 up and down in the Z-axis direction relative to the chuck table 10, but a configuration may also be adopted in which the chuck table 10 moves up and down in the Z-axis direction relative to the processing mechanism 30, conversely.

[0044] Furthermore, in the above embodiment, a configuration was adopted in which the Y-axis moving mechanism 60 moves the processing mechanism 30 horizontally in the Y-axis direction relative to the chuck table 10, but a configuration may also be adopted in which the chuck table 10 moves horizontally in the Y-axis direction relative to the processing mechanism 30, conversely. A configuration in which the actuator moves up and down in the Z-axis direction may also be adopted.

[0045] Furthermore, the present invention is not limited to the application of the above-described embodiments, and it goes without saying that various modifications are possible within the scope of the claims and the technical ideas described in the specification and drawings. [Explanation of symbols]

[0046] 1: Edge trimming device, 2: Base, 3: Gate column, 10: Chuck table, 11: suction groove, 12: suction path, 13: rotary joint, 14: piping, 15: suction source, 16: Support, 17: Bearing, 20: Rotation mechanism, 30: Processing mechanism, 31: spindle housing, 32: imaging unit, 33: spindle, 34: spindle motor, 35: cutting blade, 35a: outer surface (one surface) of the cutting blade; 35b: inner surface (the other surface) of the cutting blade; 35c: outer peripheral surface of cutting blade, 40: X-axis moving mechanism, 41: X-axis guide rail, 42: slider, 43: X-axis ball screw, 44: X-axis servo motor, 50: Z-axis movement mechanism, 51: Z-axis guide rail, 52: lifting plate, 53: Z-axis ball screw, 54: Z-axis servo motor, 60: Y-axis movement mechanism, 61: slider, 62: Y-axis guide rail, 63: Y-axis ball screw, 64: Y-axis servo motor, 70: control section, 71: first control section, 72: second control section, B: width of machined groove, CL: center axis, h: depth of the groove, R: chamfered portion of the wafer, V: on-off valve, W: wafer, Wa: Machined groove, Wa1: Side of machined groove, Wa2: Bottom of machined groove

Claims

1. An edge trimming method for forming a ring-shaped groove on the outer periphery of a wafer held on a chuck table by cutting a cutting blade into the outer periphery of the wafer and rotating the wafer and the cutting blade, comprising: a groove forming step of cutting the wafer to a predetermined depth with one side of the cutting blade positioned radially inward from the outer peripheral edge of the wafer and the other side of the cutting blade positioned radially outward from and above the outer peripheral edge of the wafer, thereby forming a ring-shaped groove on the outer peripheral edge of the wafer; a corner correction step in which the other side surface and the outer peripheral surface of the cutting blade are brought into contact with the side surface and the bottom surface of the groove formed in the groove forming step, respectively, to cut the groove, thereby correcting the corner portion between the side surface and the bottom surface of the groove to a right angle; 1. An edge trimming method comprising:

2. a chuck table for holding the wafer; a processing mechanism that cuts the outer periphery of the wafer by rotating a cutting blade attached to the tip of a spindle; a Z-axis movement mechanism that moves the chuck table and the processing mechanism relative to each other in a cutting feed direction of the cutting blade; a rotation mechanism that moves the chuck table and the processing mechanism relative to each other in a circumferential direction around the center of the wafer held on the chuck table; a Y-axis movement mechanism that moves the chuck table and the processing mechanism relatively in the axial direction of the spindle; A control unit; An edge trimming device comprising: The control unit a first control unit that positions one side of the cutting blade radially inward from the outer circumferential edge of the wafer and the other side of the cutting blade radially outward from and above the outer circumferential edge of the wafer, causes the cutting blade to cut into the wafer to a predetermined depth, and rotates the wafer using the rotation mechanism, thereby forming a ring-shaped processed groove on the outer circumferential edge of the wafer; a second control unit that, after separating the cutting blade from the wafer, brings the other side surface and the outer peripheral surface of the cutting blade into contact with the side surface and the bottom surface of the groove, respectively, to cut the groove, thereby correcting the corner portion between the side surface and the bottom surface of the groove to a right angle; An edge trimming device comprising:

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