Edge trimming method and edge trimming device

Abstract

To quickly and easily set processing conditions for forming processing grooves with various cross-sectional shapes in an outer peripheral portion of a wafer.SOLUTION: An edge trimming method includes: a wafer size setting step of setting a diameter and a thickness of a wafer; a cross-sectional shape setting step of setting a cross-sectional shape of a processing groove to be formed in an outer peripheral portion of the wafer; a revolution speed setting step of setting the revolution speed of a chuck table in forming the processing groove having a cross-sectional shape set in the cross-sectional shape setting step; a processing condition calculation step of calculating processing conditions, such as a rotational speed of the chuck table and a radial position and a cutting depth of a cutting blade, from the cross-sectional shape of the processing groove set in the cross-sectional shape setting step and the revolution speed of the chuck table set in the revolution speed setting step; and a processing groove formation step of forming a processing groove in an outer peripheral portion of the wafer based on the processing conditions calculated in the processing condition calculation step.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an edge trimming method and an edge trimming device for forming a ring-shaped groove in the outer periphery (edge ​​portion) of a wafer by trimming. [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). In response to recent demands for thinner and smaller electronic devices, wafers are being ground to a thinner finish. To prevent cracks and dust generation during the manufacturing process, wafers that are ground to a thinner finish are subjected to edge trimming, which cuts the outer periphery of the wafer with a cutting blade to form a ring-shaped groove (see, for example, Patent Documents 1 and 2). In this edge trimming process, the cutting blade cuts into the outer periphery of the wafer to a predetermined depth while rotating the cutting blade and the wafer, thereby forming a ring-shaped groove in the outer periphery of the wafer.

[0004] As disclosed in Patent Documents 3 and 4, there are cases where a slanted groove or a groove with a circular arc cross section is formed on the outer periphery of a wafer. To form such a groove, it is necessary to set the machining conditions so that the cross section of the groove has a predetermined shape. The machining conditions are set by setting the cutting depth of the cutting blade per wafer rotation and the position of the cutting blade in the radial direction of the wafer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-245167 [Patent Document 2] Japanese Patent Publication No. 2022-151350 [Patent Document 3] Patent Publication No. 2021-193711 [Patent Document 4] Japanese Patent Publication No. 2023-091816 Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is a problem in that setting the processing conditions for forming processed grooves of various cross-sectional shapes, i.e., setting the cutting depth of the cutting blade for each rotation of the wafer and the position of the cutting blade in the radial direction of the wafer, is not easy and requires a lot of time and effort.

[0007] The present invention has been made in view of the above problems, and its object is to provide an edge trimming method and an edge trimming apparatus that can easily set, in a short time, the processing conditions for forming processed grooves of various cross-sectional shapes on the outer periphery of a wafer. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the edge trimming method of the present invention is a method for cutting a cutting blade into the outer periphery of a wafer held on a chuck table, and forming a ring-shaped machined groove in the outer periphery of the wafer while rotating the wafer and the cutting blade, and is characterized by comprising: a wafer size setting step for setting the diameter and thickness of the wafer; a cross-sectional shape setting step for setting the cross-sectional shape of the machined groove to be formed in the outer periphery of the wafer; a rotation count setting step for setting the number of rotations of the chuck table when forming the machined groove having the cross-sectional shape set in the cross-sectional shape setting step; a machining condition calculation step for calculating machining conditions such as the rotation speed of the chuck table, the radial position and cutting depth of the cutting blade from the cross-sectional shape of the machined groove set in the cross-sectional shape setting step and the number of rotations of the chuck table set in the rotation count setting step; and a machined groove forming step for forming the machined groove in the outer periphery of the wafer based on the machining conditions calculated in the machining condition calculation step.

[0009] an X-axis movement mechanism for relatively moving the chuck table and the processing mechanism in a Y-axis direction which is the rotation axis direction of the cutting blade; an X-axis movement mechanism for relatively moving the chuck table and the processing mechanism in an X-axis direction which is orthogonal to the Z-axis direction and the Y-axis direction; an X-axis movement mechanism for relatively moving the chuck table and the processing mechanism in an X-axis direction which is orthogonal to the Z-axis direction and the Y-axis direction; a rotation mechanism for rotating the chuck table around a vertical central axis; a touch panel; and a control unit. The touch panel has a wafer size setting unit for setting the diameter and thickness of the wafer, a cross-section display unit for displaying the cross-sectional shape of the wafer based on the diameter and thickness of the wafer set in the wafer size setting unit, a type setting unit for setting the cross-sectional shape type of the cross-sectional groove to be formed in the outer periphery of the wafer, and a type setting unit for setting the width of the cross-sectional groove to be formed. a width setting unit for setting a depth of the machined groove to be formed, a depth setting unit for setting the depth of the machined groove to be formed, a rotation count setting unit for setting the number of rotations of the chuck table, and a selection unit for selecting step machining or spiral machining as the method for forming the machined groove, wherein when step machining is selected by the selection unit, the control unit controls to change the height of the cutting blade relative to the wafer by dividing the depth of the machined groove set in the depth setting unit by the number of rotations of the chuck table set in the rotation count setting unit, and to change the position of the cutting blade in the Y-axis direction relative to the wafer by dividing the width of the machined groove set in the width setting unit by the number of rotations of the chuck table set in the rotation count setting unit, and when spiral machining is selected by the selection unit, controls to continuously move the cutting blade in the Z-axis direction and the Y-axis direction, respectively, while continuously rotating the chuck table. [Effects of the Invention]

[0010] According to the edge trimming method of the present invention, which is carried out using the edge trimming device of the present invention, when the size of the wafer (diameter and thickness) and the cross-sectional shape of the groove to be formed on the outer periphery of the wafer are set on the touch panel, the processing conditions for the cross-sectional shape of the groove to be formed are calculated, and the outer periphery of the wafer is ground with a cutting blade based on these processing conditions to form a groove of the desired cross-sectional shape, thereby achieving the effect that the processing conditions for forming grooves of various cross-sectional shapes on the outer periphery of the wafer can be easily set in a short time. [Brief explanation of the drawings]

[0011] [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 according to the present invention. [Figure 3] FIG. 2 is a front view showing a display screen of a touch panel. [Figure 4] 1(a) to 1(e) are diagrams showing various cross-sectional shapes of machined grooves. [Figure 5] 1 is a block diagram showing each step of an edge trimming method according to a first embodiment of the present invention. [Figure 6] 1 is a flowchart showing the procedure of an edge trimming method according to a first embodiment of the present invention. [Figure 7] 3A and 3B are explanatory diagrams showing the process of forming a processed groove by the edge trimming method according to the first embodiment of the present invention, in which (a) is an explanatory diagram showing the process of forming a processed groove having the cross-sectional shape shown in FIG. 3B, and (b) is an explanatory diagram showing the process of forming a processed groove having the cross-sectional shape shown in FIG. 3C. [Figure 8] 10 is a flowchart showing the procedure of an edge trimming method according to a second embodiment of the present invention. [Figure 9] 4A to 4C are explanatory views showing a process of forming a processed groove having a cross-sectional shape shown in FIG. 3B by an edge trimming method according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0013] [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 and 2. In the following description, as shown by the arrows in Figure 1, 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.

[0014] 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 portal column 3 is vertically erected at the rear end (-X axis direction end) of this base 2.

[0015] The edge trimming apparatus 1 includes, as its main components, a chuck table 10 that holds and rotates a thin, disk-shaped wafer W (see FIG. 2 ), a rotation mechanism 20 that rotates the chuck table 10 about a vertical center axis CL, 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 moves the chuck table 10 together with the wafer W along the X-axis, a Z-axis movement mechanism 50 that raises and lowers the processing mechanism 30 along the Z-axis, a Y-axis movement mechanism 60 that moves the processing mechanism 30 along the Y-axis, a control unit 70 that controls the operations of the various components, and a touch panel 80 that inputs and displays processing conditions. 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, the control unit 70, and the touch panel 80.

[0016] (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 as shown in FIG. 2, this suction groove 11 is connected to a suction path 12 that connects one point on the outer periphery of the chuck table 10 to a suction source 15.

[0017] 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.

[0018] 2, the chuck table 10 has a rotation shaft 10A extending downward from the center thereof, and this rotation shaft 10A is rotatably supported by a cylindrical support column 16 via a bearing 17. Therefore, the chuck table 10 is rotatably supported by the support column 16 via the bearing 17, and the support column 16 is provided vertically on a slider 42 of an X-axis movement mechanism 40, which will be described later.

[0019] 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 surface (the upper surface in FIG. 2) is divided into a plurality of rectangular regions by lattice-like dividing lines (streets) that are perpendicular to each other, and devices (not shown), such as ICs and LSIs, are formed in each rectangular region.

[0020] (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 Fig. 2 at a predetermined speed, and is housed inside the support column 16 that rotatably supports the chuck table 10. Although the details of the 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 so that its operation is controlled by the control unit 70.

[0021] (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.

[0022] The rectangular box-shaped spindle housing 31 houses a spindle motor 34 that rotates a spindle 33 (see FIG. 2) 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.

[0023] (X-axis movement mechanism) The X-axis moving mechanism 40 is a mechanism for moving 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.

[0024] Therefore, when the X-axis servo motor 44 is started to rotate the X-axis ball screw 43, 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 together with the slider 42 and the rotation mechanism 20 in the X-axis direction.

[0025] (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 includes a pair of Z-axis guide rails 51 arranged parallel to each other and perpendicular to the left and right 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, a reversible Z-axis servo motor 54 that rotationally drives the Z-axis ball screw 53, and an encoder 55 that detects the rotation speed and rotation direction of the Z-axis servo motor 54. 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.

[0026] The encoder 55 is electrically connected to the control unit 70, and the detection signal is transmitted to the control unit 70, which determines the position of the cutting blade 35 in the Z-axis direction.

[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 moving the processing mechanism 30 along the Y-axis direction, and includes 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 vertically erected 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 disposed along the Y-axis between a pair of upper and lower Y-axis guide rails 62. A nut member (not shown) protruding 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, which serves as a rotational drive source. The Y-axis servo motor 64 is provided with an encoder 65 that detects the rotation speed and direction of the Y-axis servo motor 64. The Y-axis servo motor 64 and the encoder 65 are electrically connected to a control unit 70. The operation of the Y-axis servo motor 64 is controlled by the control unit 70, and a detection signal from the encoder 65 is sent to the control unit 70 to determine the position of the cutting blade 35 in the Y-axis direction.

[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 drawing control unit 71 and a drawing setting control unit 72, as shown in Fig. 2, and the specific functions of the drawing control unit 71 and the drawing setting control unit 72 will be described later.

[0033] (touch panel) The touch panel 80 shown in FIG. 1 is used by an operator to input and set processing conditions and displays necessary information, and its display screen is shown in FIG. That is, the display screen of the touch panel 80 shown in Figure 3 displays a wafer size setting section 81 for inputting the diameter and thickness indicating the size of the wafer W, a cross-section display section 82 for displaying a cross-section of the wafer W corresponding to the size of the wafer W set in the wafer size setting section 81, a type setting section 83 for selecting and setting the type of machining groove Wa to be formed on the outer periphery of the wafer W (for example, the cross-sectional shape of the machining grooves Wa1 to Wa5 shown in Figures 6(a) to 6(e)), a width setting section 84 for setting the width B of the machining groove Wa (Wa1 to Wa5), a depth setting section 85 for setting the depth h of the machining groove Wa (Wa1 to Wa5), a rotation number setting section 86 for setting the rotation number N of the chuck table 10, and a machining setting section 831 for setting a step machining or spiral machining, which will be described later, as the method of forming the machining groove Wa (Wa1 to Wa5) (machining method).

[0034] 3, the display screen of the touch panel 8 displays the machining conditions calculated for the set type of machining groove Wa (cross-sectional shapes of the machining grooves Wa1 to Wa5 shown in FIGS. 6(a) to (e)). Specifically, when the set machining groove Wa (Wa1 to Wa5) is formed by step machining, the cutting depth h of the cutting blade 35 in each machining step i (i=1 to 6) formed by grinding with the cutting blade 35 is i and the rotation speed u of the chuck table 10 i and the radial position (in this embodiment, the movement amount (index) in the Y-axis direction) y i is displayed for each processing step i (i = 2 to 6).

[0035] In this embodiment, one rotation of the chuck table 10 is equal to one machining step, but the number of machining steps (number of rotations of the chuck table 10) N is set to 6 (N=6). Therefore, the cutting depths h1 to h6 (see FIG. 7) of the cutting blade 35 in each of the machining steps 1 to 6 are displayed in the cutting depth display unit 87, and the rotation speeds u1 to u6 of the chuck table 10 in each of the machining steps 1 to 6 are displayed in the speed display unit 88. In addition, the Y-axis direction movement amount (index) y of the cutting blade 35 in each of the machining steps 2 to 6 is displayed in the Y-axis direction (see FIG. 7). i (See FIG. 7) is displayed in the index display section 89.

[0036] In addition, although not shown, the touch panel 80 is equipped with a display control unit that displays the cross-sectional shape of the processing groove Wa (Wa1 to Wa5) to be formed on the cross-section display unit 82 based on the cross-sectional shape type set in the type setting unit 83, the width B set in the width setting unit 84, and the depth h set in the depth setting unit 85.

[0037] [Edge trimming method] Next, an embodiment of the edge trimming method according to the present invention, which is carried out in the edge trimming device 1 configured as above, will be described.

[0038] First Embodiment An edge trimming method according to a first embodiment of the present invention will be described below with reference to FIGS.

[0039] The edge trimming method according to this embodiment is a method for forming grooves Wa of a predetermined width B and a predetermined depth h in the outer periphery of a wafer W by cutting (edge ​​trimming) using a cutting blade 35 through step processing. To form grooves Wa (Wa1 to Wa5) in the outer periphery of the top surface (the surface on which a device, not shown, is formed) of the wafer W by cutting using the cutting blade 35, first, the wafer W is placed on the holding surface of the chuck table 10, as shown in Fig. 2. Then, the control unit 70 opens the on-off valve V, and a ring-shaped suction groove 11 opening into 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 (see Fig. 2).

[0040] In this embodiment, step machining is set by touching a machining setting button 832 in the machining setting section 831 shown in Figure 3 to select and set step machining or spiral machining as the method (machining method) for forming the machining groove Wa (Wa1 to Wa5).

[0041] 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 placed on the holding surface of the chuck table 10 is held by suction 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 images the surface and outer periphery of the wafer W. Once the position of the outer periphery of the wafer W is detected by this imaging, processing grooves Wa (Wa1 to Wa5) are formed in the outer periphery of the wafer W in the following procedure.

[0042] Therefore, the edge trimming method according to this embodiment includes the following steps, as shown in FIG. 1) Wafer size setting process: 2) Cross-sectional shape display process: 3) Cross-sectional shape setting process: 4) Rotation speed setting process 5) Machining condition calculation process: 6) Machining groove forming process: By carrying out the above steps in this order, a groove Wa having a predetermined shape with a width B and a depth h is formed on the outer periphery of the wafer W. Each step will be explained below.

[0043] 1) Wafer size setting process: In the wafer size setting process, the diameter and thickness of the wafer W are input and set by the operator in a wafer size setting section 81 displayed on the touch panel 80 shown in Fig. 3 (step S1 in Fig. 5). At the same time, the width B and depth h of the processing groove Wa to be formed on the outer periphery of the wafer W are input and set by the operator in a width setting section 84 and a depth setting section 85, respectively, on the display screen of the touch panel 80 shown in Fig. 3.

[0044] 2) Cross-sectional shape display process: As described above, when the diameter and thickness of the wafer W are input and set in the wafer size setting section 81 of the touch panel 80, the cross-sectional shape of the outer periphery of the wafer W is displayed in the cross-section display section 82 of the touch panel 80 (step S2 in FIG. 5).

[0045] 3) Cross-sectional shape setting process: In the cross-sectional shape display process, which is a preceding process, when the cross-sectional shape of the wafer W is displayed on the cross-sectional display section 82 of the touch panel 80, the operator traces with his / her finger the cross-sectional shape of the processing groove Wa to be formed on the cross-sectional shape of the wafer W displayed on the cross-sectional display section 82. Then, the drawing control section 71 (see FIG. 2) of the control section 70 displays the cross-sectional shape of the processing groove Wa to be formed on the cross-sectional display section 82 of the touch panel 80, and the drawing setting control section 72 of the control section 70 sets the cross-sectional shape of the processing groove Wa to be formed (step S3 in FIG. 5).

[0046] Here, examples of the cross-sectional shapes of the processing groove Wa formed on the outer periphery of the wafer W are shown in Figures 6(a) to (e). The processing groove Wa1 shown in Figure 6(a) has a rectangular cross-section (trim shape) formed by grinding the outer periphery of the wafer W along a vertical cut surface C1 and a cut surface C2 extending horizontally from the lower end of the cut surface C1.

[0047] The groove Wa2 shown in Fig. 6(b) has a triangular cross-section (bevel shape) formed by grinding the outer periphery of the wafer W along a sloped cut surface C3. The groove Wa3 shown in Fig. 6(c) has a rounded cross-section formed by grinding the outer periphery of the wafer W along a convex cut surface C4. The groove Wa4 shown in Fig. 6(d) has a trapezoidal cross-section (trim + bevel shape) formed by grinding the outer periphery of the wafer W along a vertical cut surface C5 and a cut surface C6 that slopes diagonally downward from the lower end of the cut surface C5 toward the radially outward direction of the wafer W. The groove Wa5 shown in Fig. 6(e) has a reverse rounded cross-section formed by grinding the outer periphery of the wafer W along a concave cut surface C7. The widths of the grooves Wa1 to Wa5 shown in Figs. 6(a) to 6(e) are set to B, and the depths are set to h.

[0048] In this embodiment, the cross-sectional shape of the processing groove Wa to be formed is set by the operator manually tracing and drawing the cross section of the wafer W displayed on the cross-section display section 82 of the touch panel 80. However, for example, the processing grooves Wa1 to Wa5 having the cross-sectional shapes shown in Figures 6(a) to 6(e) may be displayed on the cross-section display section 82 of the touch panel 80, and the operator may touch the type setting button 83a with his / her finger to display a list of cross-sectional shapes, from which the desired cross-sectional shape can be selected.

[0049] 4) Rotation speed setting process: The rotation number setting step is a step of setting the number of times N to rotate the chuck table 10 when forming a machined groove Wa of a predetermined width B and a predetermined depth h, and in this embodiment, as will be described later, the cutting blade 35 is moved (indexed) a predetermined amount in the Y-axis direction by the Y-axis movement mechanism 60 with each rotation of the chuck table 10, and then the cutting blade 35 is caused to cut a predetermined amount by the Z-axis movement mechanism 50, thereby forming a machined groove Wa of a desired cross-sectional shape. Therefore, in this embodiment, the number of rotations N of the chuck table 10 matches the number of processing steps, as described above.

[0050] In this embodiment, the grinding of the wafer W is divided into six processing steps, and in this process, the number of divisions is set as the number of processing steps N (step S4 in FIG. 5). In this embodiment, the number of rotations (number of processing steps) N of the chuck table 10 is set to 6 (N=6), and as will be described later, in the processed groove forming process, the grinding of the wafer W is divided into six processing steps. Here, the number of rotations N of the chuck table 10 is set by the operator inputting a number into a rotation number setting section 86 displayed on the display screen of the touch panel 80 shown in FIG.

[0051] 5) Machining condition calculation process: In the machining condition calculation step, the control unit 70 calculates the rotation speed u of the chuck table 10 in each machining step i (i=1, 2, 3...6) from the cross-sectional shape of the machined groove Wa (Wa1 to Wa5) set in the cross-sectional shape setting step and the number of rotations (number of machining steps) N set in the rotation number setting step. i and the Y-axis movement amount (index) y of the cutting blade 35 i and cutting depth h i The machining conditions such as the above are calculated (step S5 in FIG. 5).

[0052] In this embodiment, the number of machining steps N is set to 6 (N=6), and therefore the width B of the machined groove Wa (Wa1 to Wa5) set in the width setting section 84 of the touch panel 80 is divided into 6, and the depth h set in the depth setting section 85 of the touch panel 80 is also divided into 6. Then, the Y-axis movement amounts (indexes) y2 to y6 (see FIGS. 3 and 7) of the cutting blade 35 in each machining step i (i=2, 3, . . . 6) as well as the rotational speeds u1 to u6 (see FIG. 3) of the chuck table 10 in each machining step i and the cutting depths h1 to h6 (see FIGS. 3 and 7) of the cutting blade 35 in each machining step i are calculated, and these values ​​are displayed in the index display section 89, the rotational speed display section 88 and the cutting depth display section 87 on the display screen of the touch panel 80 shown in FIG. 3, respectively, and are also stored in the memory of the control section 70.

[0053] 6) Machining groove forming process: In the machining groove forming process, the outer periphery of the wafer W is ground by the cutting blade 35 for each machining step i based on the Y-axis direction movement amounts (indexes) y2 to y6 (see FIGS. 3 and 7) of the cutting blade 35 for each machining step i calculated under the machining conditions in the previous process, the rotational speeds u1 to u6 of the chuck table 10 for each machining step i (see FIG. 3), and the cutting depths h1 to h6 of the cutting blade 35 (see FIGS. 3 and 7). First, prior to machining, the machining step number i is set to 1 (i=1) (step S6 in FIG. 5). In this embodiment, the machining step number i is set to i=1 to 6 (first step to sixth step).

[0054] 7(a) and 7(b) show the movement trajectories of the cutting blade 35 when forming the groove Wa2 having the cross-sectional shape (bevel shape) shown in FIG. 6(b) and the groove Wa3 having the cross-sectional shape (round shape) shown in FIG. 6(c), respectively. When forming these grooves Wa2 and Wa3, the control unit 70 reads the rotation speed u1 of the chuck table 10 and the cutting depth h1 of the cutting blade 35 in the first step stored in the memory unit (step S7 in FIG. 5). Then, the Y-axis moving mechanism 60 moves the cutting blade 35 in the Y-axis direction to position its outer surface 35a at a predetermined Y-axis position (an initial position radially inward by a width B from the outer periphery of the wafer W) (step S8 in FIG. 5). Then, while rotating the chuck table 10 at the rotation speed u1, the Z-axis moving mechanism 50 moves (lowers) the cutting blade 35 in the Z-axis direction to cut the wafer W by the cutting depth h1 (step S9 in FIG. 5).

[0055] In this embodiment, an outer periphery reference method is adopted in which the Y-axis position (initial position) where the cutting blade 35 first cuts in is set to a position radially inward by a predetermined width B from the outer periphery of the wafer W detected by the imaging unit 32, but a center reference method may also be adopted in which a position radially inward by a predetermined width B from the known outer diameter of the wafer W is set as the cutting start position of the cutting blade 35.i (i=1, 2, 3 . . . 6) are set to values ​​that make the peripheral speed of the chuck table 10 relative to the cutting blade 35 the same.

[0056] Thereafter, the step number i is incremented by one (i=i+1) (step S10 in FIG. 5), and the control unit 70 calculates the Y-axis direction movement amount (index) y of the cutting blade 35 in the second to sixth steps stored in the storage unit. i , the rotation speed u of the chuck table 10 i and the cutting depth h of the cutting blade 35 i (Step S11 in FIG. 5), and the cutting blade 35 is moved in the Y-axis direction by the Y-axis movement amount (index) y i (Step S12 in FIG. 5), and the chuck table 10 is rotated at a rotation speed u i The cutting blade 35 is rotated at a speed of h i (Step S13 in FIG. 5). Then, it is determined whether or not the step number i has reached a predetermined number of steps N (=6), that is, whether or not the machining in the first to sixth steps has been completed (Step S14 in FIG. 5).

[0057] When the cutting process in the second step is completed, the step number i is set to i=3 (step S10 in FIG. 5), so the determination result in step S14 is No, and thereafter, the processes of steps S11 to S14 are repeated the number of times corresponding to the number of steps. Then, in a sixth step (i=6), the cutting blade 35 is moved in the Y-axis direction by an index y6 (step S12 in FIG. 5), and while the chuck table 10 is rotated once at a rotation speed u6, the Z-axis movement mechanism 50 moves (lowers) the cutting blade 35 in the Z-axis direction to cut the wafer W by a cutting depth h6 (step S13 in FIG. 5). This completes the processing in the first to sixth steps, and a machined groove Wa2 having a cross-sectional shape (bevel shape) shown in FIG. 7(a) or a machined groove Wa3 having a cross-sectional shape (round shape) shown in FIG. 7(c) is formed in the outer periphery of the wafer W. The processed grooves Wa1, Wa4, and Wa5 having the cross-sectional shapes shown in FIGS. 6(a), 6(d), and 6(e) can also be formed in the same manner as above.

[0058] Therefore, when the processing in the sixth step is completed, the number of processing steps i is set to N (=6), so the judgment result in step S14 becomes Yes, and the series of processing operations on the wafer W is completed (step S15 in Figure 5).

[0059] As is clear from the above explanation, according to the edge trimming method of this embodiment, the size (diameter and thickness) of the wafer W and the number of rotations N of the chuck table 10 (number of processing steps) are input and set on the touch panel 80, and the cross-sectional shape of the processed groove Wa to be formed on the outer periphery of the wafer W is set, and then the processing conditions for each processing step (the Y-axis movement amount (index) y of the cutting blade 35) are set. i and the rotation speed u of the chuck table 10 i and the cutting depth h of the cutting blade 35 i ) is calculated, and based on these processing conditions, the outer periphery of the wafer W is ground by the cutting blade 35 to form a processed groove Wa of a desired cross-sectional shape on the outer periphery of the wafer W, thereby achieving the effect that processing conditions for forming processed grooves Wa of various cross-sectional shapes on the outer periphery of the wafer W can be easily set in a short time.

[0060] In this embodiment, the number of processing steps N when forming a processing groove Wa by step processing on the outer periphery of the wafer W is set to 6 (N=6). However, this number of processing steps N can be any number as long as it is plural, and the larger the number of processing steps N, the more accurately a processing groove Wa with the desired cross-sectional shape can be formed.

[0061] Second Embodiment Next, an edge trimming method according to a second embodiment of the present invention will be described below with reference to FIGS.

[0062] The edge trimming method according to this embodiment is a method of forming a groove Wa of a predetermined width B and a predetermined depth h in the outer periphery of the wafer W by cutting (edge ​​trimming) using a cutting blade 35 through spiral machining. Specifically, the chuck table 10 is continuously rotated, and the cutting blade 35 is continuously moved in the Z-axis direction and the Y-axis direction at predetermined moving speeds, respectively, to form the groove Wa in the outer periphery of the wafer W.

[0063] In this embodiment, a machining setting button 832 is touched in the machining setting section 831 to select and set step machining or spiral machining as the method (machining method) for forming the machining groove Wa (Wa1 to Wa5), and spiral machining is set.

[0064] 2, in the edge trimming method according to this embodiment, the wafer W is placed on the holding surface of the chuck table 10 and the wafer W is suction-held on the holding surface of the chuck table 10. Then, in this embodiment as well, a processed groove Wa having a desired cross-sectional shape is formed on the outer periphery of the wafer W by sequentially performing the following steps shown in FIG. 1) Wafer size setting process: 2) Cross-sectional shape display process: 3) Cross-sectional shape setting process: 4) Rotation speed setting process 5) Machining condition calculation process: 6) Machining groove forming process: Each step will be explained below.

[0065] 1) Wafer size setting process: In the wafer size setting process, the diameter and thickness of the wafer W are input and set by the operator in a wafer size setting section 81 displayed on the touch panel 80 shown in Fig. 3 (step S21 in Fig. 8). At the same time, the width B and depth h of the processing groove Wa to be formed in the outer periphery of the wafer W are input and set by the operator in a width setting section 84 and a depth setting section 85, respectively, on the display screen of the touch panel 80 shown in Fig. 3.

[0066] 2) Cross-sectional shape display process: As described above, when the diameter and thickness of the wafer W are input and set in the wafer size setting section 81 of the touch panel 80, the cross-sectional shape of the wafer W is displayed in the cross-section display section 82 of the touch panel 80 (step S22 in FIG. 8).

[0067] 3) Cross-sectional shape setting process: In the cross-sectional shape display process, which is a preceding process, when the cross-sectional shape of the wafer W is displayed on the cross-sectional display section 82 of the touch panel 80, the operator traces with his / her finger the cross-sectional shape of the processing groove Wa to be formed on the cross-sectional shape of the wafer W displayed on the cross-sectional display section 82. Then, the drawing control section 71 of the control section 70 (see FIG. 2) displays the cross-sectional shape of the processing groove Wa to be formed on the cross-sectional display section 82 of the touch panel 80, and the drawing setting control section 72 of the control section 70 sets the cross-sectional shape of the processing groove Wa to be formed (step S23 in FIG. 8).

[0068] In this embodiment, the cross-sectional shape of the processing groove Wa to be formed is set by the operator manually tracing and drawing the cross section of the wafer W displayed on the cross-section display section 82 of the touch panel 80. However, for example, the processing grooves Wa1 to Wa5 having the cross-sectional shapes shown in Figures 6(a) to 6(e) may be displayed on the cross-section display section 82 of the touch panel 80, and the operator may touch the type setting button 83a with his / her finger to display a list of cross-sectional shapes, from which the desired cross-sectional shape can be selected.

[0069] 4) Rotation speed setting process: The rotation count setting step is a step of setting the number of times N the chuck table 10 is rotated when forming a machined groove Wa with a predetermined width B and a predetermined depth h (step S24 in FIG. 8 ). In this embodiment, as described below, the chuck table 10 is continuously rotated, and the cutting blade 35 is continuously moved in the Z-axis direction and the Y-axis direction at a Z-axis moving speed and a Y-axis moving speed, respectively, for each rotation of the chuck table 10, to form a machined groove Wa on the outer periphery of the wafer W. This rotation count setting step is a step of setting the number of times N the chuck table 10 is rotated until a machined groove Wa with a desired cross-sectional shape is formed, and in this embodiment, N is set to 6. That is, in this embodiment, the machined groove Wa is formed on the outer periphery of the wafer W by rotating the chuck table 10 only six times. Note that in this embodiment, the number of rotations N of the chuck table 10 when forming the machined groove Wa is set to 6 (N=6), but this number of rotations N may be any number greater than one.

[0070] 5) Machining condition calculation process: In the machining condition calculation process, the control unit 70 calculates the Z-axis direction movement speed and Y-axis direction movement speed of the cutting blade 35 from the cross-sectional shape of the machining groove Wa set in the cross-sectional shape setting process and the number of rotations N of the chuck table 10 set in the number of rotations setting process (step S25 in Figure 8), and stores the results in the memory unit.

[0071] 6) Machining groove forming process: In the groove forming step, the chuck table 10 is continuously rotated (step S26 in FIG. 8 ), and the cutting blade 35 is continuously moved in the Z-axis direction and the Y-axis direction at the Z-axis and Y-axis speeds calculated in the preceding processing condition calculation step, respectively, to form a groove Wa2 having a cross-sectional shape (bevel shape) such as that shown in FIG. 6( b) on the outer periphery of the wafer W (step S27 in FIG. 8 ). While the groove Wa2 is being formed, the depth of the groove Wa2 is detected (step S28 in FIG. 8 ), and it is determined whether the detected depth has reached a predetermined depth h (step S29 in FIG. 8 ). The depth of the groove Wa2 is calculated by the control unit 70 based on the rotation speed of the Z-axis servo motor 54 detected by the encoder 55 of the Z-axis movement mechanism 50 shown in FIG. 2 .

[0072] When the depth of the groove Wa2 formed in the outer periphery of the wafer W reaches a predetermined value h (step S29: Yes), the control unit 70 rotates the chuck table 10 one final time (step S30) and ends the series of grinding processes on the wafer W (step S31). As a result, a groove Wa2 (see FIG. 6(b)) having a predetermined cross-sectional shape is formed in the outer periphery of the wafer W. If the depth of the groove Wa2 has not reached the predetermined value h (step S29: No), steps S26 to S29 are repeated and the grinding process on the wafer W continues until the depth of the groove Wa2 reaches the predetermined value h.

[0073] As described above, in the edge trimming method according to this embodiment, the size (diameter and thickness) of the wafer W and the number of rotations N of the chuck table 10 are input and set on the touch panel 80, and the cross-sectional shape of the machining groove Wa to be formed on the outer periphery of the wafer W is set, and the machining conditions are calculated. Based on these machining conditions, the chuck table 10 is continuously rotated while the cutting blade 35 moves continuously in the Z-axis and Y-axis directions at predetermined speeds, grinding the outer periphery of the wafer W to form a machining groove Wa of the desired cross-sectional shape on the outer periphery of the wafer W. This provides the advantage that the machining conditions for forming machining grooves Wa of various cross-sectional shapes on the outer periphery of the wafer W can be easily set in a short time.

[0074] In the edge trimming method according to the first embodiment, the cutting blade 35 is moved in the Y-axis direction by a predetermined index amount at each step, and the cutting groove Wa is cut to a predetermined depth in that state, resulting in a stepped cut surface, as shown in Figures 7(a) and 7(b). However, in this embodiment, the cutting blade 35 is continuously moved in the Z-axis and Y-axis directions while grinding the outer periphery of the wafer W, resulting in a smooth cut surface C3 that conforms to the desired shape. However, the cut surface C3 is a slightly inclined spiral surface.

[0075] 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.

[0076] 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.

[0077] 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]

[0078] 1: Edge trimming device, 2: Base, 3: Gate column, 10: Chuck table, 10A: Rotating shaft, 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 of cutting blade 40: X-axis movement 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, 55: encoder, 60: Y-axis movement mechanism, 61: slider, 62: Y-axis guide rail, 63: Y-axis ball screw, 64: Y-axis servo motor, 65: encoder, 70: control unit, 71: drawing control unit, 72: drawing setting control unit, 80: touch panel, 81: wafer size setting unit, 82: Cross section display section, 83: Type setting section, 83a: Type setting button, 831: Processing setting section, 832: Processing setting button, 84: Width setting section, 85: Depth setting section, 86: rotation number setting unit, 87: cutting amount display unit, 88: rotation speed display unit, 89: Index display section, B: Width of the processed groove, C1 to C7: Cut surface, CL: Center axis, h: depth of the groove, h1 to h6: cutting depth of the cutting blade, N: number of processing steps, y2 to y6: Y-axis movement distance (index) of cutting blade, V: opening / closing valve, W: wafer, Wa (Wa1~Wa5): Machined groove

Claims

1. 1. An edge trimming method for forming a ring-shaped groove in the outer periphery of a wafer held on a chuck table by cutting a cutting blade into the outer periphery of the wafer while rotating the wafer and the cutting blade, comprising: a wafer size setting step of setting the diameter and thickness of the wafer; a cross-sectional shape setting step of setting a cross-sectional shape of a groove to be formed on the outer periphery of the wafer; a rotation number setting step for setting the number of rotations of the chuck table when forming a machined groove having the cross-sectional shape set in the cross-sectional shape setting step; a machining condition calculation step of calculating machining conditions such as the rotation speed of the chuck table, the radial position of the cutting blade, and the cutting depth from the cross-sectional shape of the machined groove set in the cross-sectional shape setting step and the number of rotations of the chuck table set in the number of rotations setting step; a groove forming step of forming a groove on the outer periphery of the wafer based on the processing conditions calculated in the processing condition calculation step; 1. An edge trimming method comprising:

2. 2. The edge trimming method according to claim 1, wherein a groove is formed in the outer periphery of the wafer based on the processing conditions calculated in the processing condition calculation step, every time the chuck table makes one rotation.

3. In the processing condition calculation step, a Z-axis movement speed for moving the cutting blade in a Z-axis direction, which is the thickness direction of the wafer, and a Y-axis movement speed for moving the cutting blade in a Y-axis direction, which is the radial direction of the wafer, are calculated; 2. The edge trimming method according to claim 1, wherein in the groove forming step, the chuck table is continuously rotated and the cutting blade is continuously moved in the Z-axis direction and the Y-axis direction, respectively, to form a groove in the outer periphery of the wafer.

4. a cross-sectional shape display step of displaying a cross-sectional shape of an outer periphery of the wafer on a touch panel based on the wafer size set in the wafer size setting step; 2. The edge trimming method according to claim 1, wherein in the cross-sectional shape setting step, the cross-sectional shape of the groove to be machined is set by the operator tracing and drawing the cross-sectional shape of the groove to be machined on the cross-sectional shape displayed on the touch panel.

5. a chuck table that holds the wafer on a holding surface; a processing mechanism that cuts a cutting blade into the outer periphery of a rotating wafer to form a ring-shaped processed groove in the outer periphery of the wafer; a Z-axis movement mechanism that moves the chuck table and the processing mechanism relatively in a Z-axis direction perpendicular to a holding surface of the chuck table; a Y-axis movement mechanism that moves the chuck table and the processing mechanism relatively in a Y-axis direction that is a rotation axis direction of the cutting blade; an X movement mechanism that moves the chuck table and the processing mechanism relatively in an X axis direction perpendicular to the Z axis direction and the Y axis direction; a rotation mechanism that rotates the chuck table about a vertical central axis; Touch panel and A control unit; An edge trimming device comprising: The touch panel is a wafer size setting unit that sets the diameter and thickness of the wafer; a cross-section display unit that displays the cross-sectional shape of the wafer based on the diameter and thickness of the wafer set in the wafer size setting unit; a type setting unit that sets a cross-sectional shape type of a processed groove to be formed on the outer periphery of the wafer; a width setting unit that sets the width of the processing groove to be formed; a depth setting unit for setting the depth of the groove to be formed; a rotation number setting unit that sets the number of rotations of the chuck table; a selection unit for selecting step machining or spiral machining as a method for forming a machining groove; Equipped with The control unit When step machining is selected by the selection unit, the depth of the machining groove set in the depth setting unit is divided by the number of rotations of the chuck table set in the rotation number setting unit to change the height of the cutting blade relative to the wafer, and the width of the machining groove set in the width setting unit is divided by the number of rotations of the chuck table set in the rotation number setting unit to change the position of the cutting blade in the Y-axis direction relative to the wafer, When spiral machining is selected by the selection unit, the edge trimming device is characterized in that, while continuously rotating the chuck table, it controls the cutting blade to continuously move in the Z-axis direction and the Y-axis direction based on the depth of the machining groove set in the depth setting unit, the number of rotations of the chuck table set in the rotation number setting unit, and the width of the machining groove set in the width setting unit.

6. The touch panel is 6. The edge trimming device according to claim 5, further comprising a drawing control unit that displays on the cross section display unit a cross section shape of the processed groove to be formed based on the cross section shape type set in the type setting unit, the width of the processed groove set in the width setting unit, and the depth of the processed groove set in the depth setting unit.

7. a drawing control unit that allows an operator to touch the cross section displayed on the cross section display unit to draw a cross section of a processing groove to be formed; a drawing setting control unit that sets the width, depth, and cross-sectional shape type of the processing groove to be formed from the cross section drawn on the touch panel; 6. The edge trimming device according to claim 5, further comprising:

Images