Cutting method for workpieces

Abstract

To provide a workpiece cutting method capable of suppressing the occurrence of machining defects.SOLUTION: A workpiece cutting method of cutting a workpiece with a cutting blade includes: a dividing line selection step of selecting a specific dividing line from among a plurality of dividing lines set on the workpiece; a dressing step of dressing the cutting blade by making the cutting blade cut into a dressing board; and a cutting step of cutting the workpiece along the specific dividing line by the cutting blade after the dressing step. After performing the dressing step and before performing the cutting step, the workpiece is not cut along the dividing line with the cutting blade.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for cutting a workpiece by using a cutting blade to cut the workpiece.

Background Art

[0002] In the manufacturing process of device chips, a wafer in which devices are formed in a plurality of regions partitioned by a plurality of division planned lines (streets) intersecting each other is used. By dividing this wafer along the division planned lines, device chips provided with devices can be obtained. The device chips are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] For dividing the wafer, a cutting device that cuts a workpiece with an annular cutting blade is used. The cutting device includes a chuck table that holds the workpiece and a cutting unit that performs cutting on the workpiece. The cutting blade is formed by fixing abrasive grains with a binder and is attached to the tip of a spindle built into the cutting unit. By holding the wafer with the chuck table and cutting into the wafer while rotating the cutting blade, the wafer is cut and divided.

[0004] When the cutting of the workpiece by the cutting blade is continued, a phenomenon called clogging occurs, in which the abrasive grains exposed from the binder are smoothed by wear and the sharpness of the cutting blade decreases, and a phenomenon called jamming occurs, in which chips (processing chips) generated by cutting the workpiece adhere to the tip of the cutting blade and part or all of the abrasive grains are buried. When cutting a workpiece with a cutting blade in a state where clogging or jamming has occurred, processing defects such as chipping are likely to occur in the workpiece, and there is a risk that the processing quality will deteriorate.

[0005] Therefore, dressing is sometimes performed to prepare the cutting blade by intentionally wearing down the tip of the cutting blade before cutting the workpiece with the cutting blade (see Patent Document 1). Dressing of the cutting blade is performed by rotating the cutting blade and cutting into a dressing material (dressing board). This eliminates dullness and clogging of the cutting blade, restores the cutting ability of the cutting blade, and suppresses the occurrence of processing defects when cutting the workpiece with the cutting blade afterward. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-192629 [Overview of the project] [Problems that the invention aims to solve]

[0007] Structures such as TEGs (Test Element Groups) and electrode pads for device inspection may be formed along the division line set on the workpiece. When the workpiece is cut along the division line along with these structures using a cutting blade, contact between the cutting blade and the structures accelerates wear and clogging of the cutting blade, leading to a deterioration of the cutting blade's condition. As a result, while the workpiece is being cut along the division line where the structures are formed, the load on the workpiece (machining load) increases rapidly, which can cause sudden machining defects such as chipping in the workpiece.

[0008] Furthermore, even if no significant machining defects occur on the planned division line where a structure is formed, the cutting blade will be in a deteriorated condition after cutting the structure. If a workpiece is cut along another planned division line with a cutting blade in this condition, machining defects are likely to occur even if no structure is formed on that division line.

[0009] This invention has been made in view of the above problems, and aims to provide a method for cutting a workpiece that can suppress the occurrence of processing defects. [Means for solving the problem]

[0010] According to one aspect of the present invention, a method for cutting a workpiece with a cutting blade, wherein a plurality of division lines set on the workpiece are provided. The first planned division line is classified into a first division line where a predetermined structure is formed and a second planned division line where the structure is not formed, and the first planned division line is classified into Specific planned division lines to A method for cutting a workpiece is provided, comprising: a step of selecting a division line to be selected; a dressing step of dressing the cutting blade by cutting into a dressing board; and a cutting step of cutting the workpiece along the specific division line with the cutting blade after the dressing step, wherein, after the dressing step and before the cutting step, the workpiece is not cut along the division line with the cutting blade.

[0011] Furthermore, according to another aspect of the present invention, a method for cutting a workpiece with a cutting blade, wherein a plurality of division lines set on the workpiece are also provided. The first planned division line is classified into a first division line where a predetermined structure is formed and a second planned division line where the structure is not formed, and the first planned division line is classified into Specific planned division lines to A method for cutting a workpiece is provided, comprising: a step of selecting a division line to be selected; a cutting step of cutting the workpiece with the cutting blade along the specific division line; and a dressing step after the cutting step of dressing the cutting blade by cutting into a dressing board, wherein, after the cutting step and before the dressing step, the cutting blade does not cut the workpiece along the division line.

[0012] Furthermore, according to another aspect of the present invention, a method for cutting a workpiece with a cutting blade, wherein a plurality of division lines set on the workpiece are provided. The first planned division line is classified into a first division line where a predetermined structure is formed and a second planned division line where the structure is not formed, and the first planned division line is classified into Specific planned division lines toA method for cutting a workpiece is provided, comprising: a step of selecting a division line to be selected; a first dressing step of dressing the cutting blade by cutting the cutting blade into a dressing board; a cutting step after the first dressing step of cutting the workpiece with the cutting blade along the specific division line; and a second dressing step after the cutting step of dressing the cutting blade by cutting the cutting blade into a dressing board, wherein the cutting blade does not cut the workpiece along the division line after the first dressing step and before the cutting step, and after the cutting step and before the second dressing step.

[0013] In addition , applicable The structure may also be TEG. [Effects of the Invention]

[0014] In a workpiece cutting method according to one aspect of the present invention, the cutting blade is dressed by cutting into a dressing board before cutting the workpiece along a specific division line with the cutting blade. This allows the workpiece to be cut along a specific division line with a cutting blade in good condition, and suppresses the occurrence of processing defects when cutting the workpiece along a specific division line.

[0015] Furthermore, in another aspect of the present invention, a method for cutting a workpiece involves cutting the workpiece along a specific division line with a cutting blade, and then dressing the cutting blade by cutting into a dressing board. This allows the workpiece to be cut along other division lines with a cutting blade in good condition, thereby suppressing the occurrence of processing defects when cutting the workpiece along other division lines. [Brief explanation of the drawing]

[0016] [Figure 1] This is a perspective view showing a cutting machine. [Figure 2]It is a perspective view showing a workpiece. [Figure 3] It is a partial cross-sectional front view showing a cutting device for cutting a workpiece. [Figure 4] It is a flowchart showing a method for cutting a workpiece. [Figure 5] It is a plan view showing a workpiece. [Figure 6] FIG. 6(A) is a partial cross-sectional front view showing the cutting device in the first dressing step, FIG. 6(B) is a partial cross-sectional front view showing the cutting device in the cutting step, and FIG. 6(C) is a partial cross-sectional front view showing the cutting device in the second dressing step.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments according to an aspect of the present invention will be described with reference to the accompanying drawings. First, a configuration example of a cutting device that can be used for implementing a method for cutting a workpiece according to the present embodiment will be described. FIG. 1 is a perspective view showing a cutting device 2. In FIG. 1, the X-axis direction (machining feed direction, first horizontal direction, front-rear direction), the Y-axis direction (indexing feed direction, second horizontal direction, left-right direction), and the Z-axis direction (vertical direction, height direction, up-down direction) are perpendicular to each other.

[0018] The cutting device 2 includes a rectangular parallelepiped base 4 that supports or houses each component constituting the cutting device 2. A rectangular opening 4a is provided at the front corner of the base 4. Inside the opening 4a, a cassette support base 6 that moves up and down by a lifting mechanism (not shown) is provided. On the upper surface of the cassette support base 6, a cassette 8 that can accommodate a plurality of workpieces 11 that are the objects of processing by the cutting device 2 is arranged. In FIG. 1, the outline of the cassette 8 is shown by a two-dot chain line.

[0019] Figure 2 is a perspective view showing the workpiece 11. For example, the workpiece 11 is a disc-shaped wafer made of a semiconductor material such as single-crystal silicon, and has a surface (first surface) 11a and a back surface (second surface) 11b that are generally parallel to each other. The workpiece 11 is divided into multiple rectangular regions by multiple division lines (streets) 13 arranged in a grid pattern so as to intersect each other. Furthermore, devices such as ICs (Integrated Circuits), LSIs (Large Scale Integrations), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) are formed in each of the multiple regions on the surface 11a side of the workpiece 11 that are divided by the division lines 13.

[0020] A structure 17 is formed on one or more specific division lines 13 out of several division lines 13. For example, the structure 17 is a TEG (Test Element Group) for inspecting the device 15, and the TEG is used to measure and evaluate the electrical characteristics of the device 15. For example, the TEG is composed of a laminate in which various thin films are stacked, such as metal films that function as wiring or electrodes, and insulating films that function as interlayer insulating films (e.g., low-dielectric constant insulating films (low-k films)).

[0021] Multiple device chips, each containing a device 15, are manufactured by dividing the workpiece 11 along the planned division line 13, along with the structure 17, to create individual pieces. There are no restrictions on the material, shape, structure, size, etc., of the workpiece 11. For example, the workpiece 11 may be a substrate made of semiconductors other than silicon (GaAs, InP, GaN, SiC, etc.), glass, ceramics, resin, metal, etc. There are also no restrictions on the type, quantity, shape, structure, size, arrangement, etc., of the devices 15 and the structure 17. For example, the structure 17 may be an electrode pad made of metal, etc.

[0022] When cutting the workpiece 11 with the cutting device 2 (see Figure 1), the workpiece 11 is supported by an annular frame 19 for ease of handling. The frame 19 is made of a metal such as SUS (stainless steel), and a circular opening 19a is provided in the center of the frame 19, penetrating the frame 19 in the thickness direction. The diameter of the opening 19a is larger than the diameter of the workpiece 11.

[0023] A circular sheet 21 is fixed to the workpiece 11 and the frame 19. For example, the sheet 21 is a tape (dicing tape) that includes a film-like base material and an adhesive layer (glue layer) provided on the base material. The base material is made of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate. The adhesive layer is made of an epoxy, acrylic, or rubber-based adhesive. The adhesive layer may also be an ultraviolet-curable resin that hardens when exposed to ultraviolet light.

[0024] With the workpiece 11 positioned inside the opening 19a of the frame 19, the central part of the sheet 21 is attached to the back surface 11b of the workpiece 11, and the outer periphery of the sheet 21 is attached to the frame 19. As a result, the workpiece 11 is supported by the frame 19 via the sheet 21, and a workpiece unit (frame unit) including the workpiece 11, frame 19, and sheet 21 is formed. Then, as shown in Figure 1, the workpiece 11 is housed in the cassette 8 while supported by the frame 19, and the cassette 8 is set on the cassette support base 6.

[0025] A rectangular opening 4b is provided to the side of the opening 4a, with its longitudinal direction aligned with the X-axis. Inside the opening 4b is a chuck table (holding table) 10 for holding the workpiece 11. The upper surface of the chuck table 10 is a flat surface that is generally parallel to the horizontal plane (XY plane) and constitutes a holding surface 10a for holding the workpiece 11. The holding surface 10a is connected to a suction source (not shown), such as an ejector, via a flow path (not shown), a valve (not shown), etc., formed inside the chuck table 10.

[0026] A moving unit 12 is connected to the chuck table 10. For example, the moving unit 12 is a ball screw type moving mechanism and comprises an X-axis ball screw (not shown) arranged along the X-axis direction and an X-axis pulse motor (not shown) that rotates the X-axis ball screw. The moving unit 12 also includes a table cover 14 that surrounds the chuck table 10. A bellows-shaped dustproof and waterproof cover 16 that can be extended and retracted along the X-axis direction is provided at the front and rear of the table cover 14. The table cover 14 and the dustproof and waterproof cover 16 are fitted so as to cover the components of the moving unit 12 (X-axis ball screw, X-axis pulse motor, etc.) located inside the opening 4b.

[0027] The moving unit 12 moves the chuck table 10 along the X-axis direction together with the table cover 14. The chuck table 10 is also connected to a rotational drive source (not shown), such as a motor, which rotates the chuck table 10 around a rotation axis that is approximately parallel to the Z-axis direction. Furthermore, multiple clamps 18 are provided around the chuck table 10 to grip and fix the frame 19 that supports the workpiece 11.

[0028] Near the openings 4a and 4b, a transport unit (not shown) is provided for transporting the workpiece 11 between the cassette 8 and the chuck table 10. The workpiece 11 is pulled out from the cassette 8 by the transport unit and transported to the chuck table 10, where it is held in place by suction.

[0029] Furthermore, a pair of chuck tables (sub-chuck tables) 20A and 20B are connected to the moving unit 12. Each of the chuck tables 20A and 20B holds a dressing board 23 used for dressing the cutting blade 46, which will be described later. For example, the chuck tables 20A and 20B are positioned at the front end of the table cover 14, spaced apart from each other in the Y-axis direction. When the moving unit 12 is driven, the pair of chuck tables 20A and 20B move along the X-axis direction together with the chuck table 10.

[0030] A gate-shaped support structure 22 is provided on the upper surface of the base 4. The support structure 22 is positioned along the Y-axis so as to straddle the opening 4b. In addition, movable units 24A and 24B are provided at both ends on the front side of the support structure 22. For example, the movable units 24A and 24B are ball screw type movable mechanisms and are mounted on a pair of Y-axis guide rails 26 positioned along the Y-axis on the front side of the support structure 22.

[0031] The moving unit 24A includes a flat Y-axis moving plate 28A. The Y-axis moving plate 28A is slidably mounted on a pair of Y-axis guide rails 26. A nut portion (not shown) is provided on the back side (rear side) of the Y-axis moving plate 28A. A Y-axis ball screw 30A, which is positioned along the Y-axis direction between the pair of Y-axis guide rails 26, is screwed into this nut portion. A Y-axis pulse motor 32, which rotates the Y-axis ball screw 30A, is connected to the end of the Y-axis ball screw 30A. When the Y-axis pulse motor 32 rotates the Y-axis ball screw 30A, the Y-axis moving plate 28A moves along the Y-axis direction along the Y-axis guide rails 26.

[0032] A pair of Z-axis guide rails 34A are fixed to the front surface of the Y-axis moving plate 28A along the Z-axis direction. A flat Z-axis moving plate 36A is slidably mounted on the pair of Z-axis guide rails 34A. A nut portion (not shown) is provided on the back surface of the Z-axis moving plate 36A. A Z-axis ball screw 38A, which is positioned between the pair of Z-axis guide rails 34A along the Z-axis direction, is screwed into this nut portion. A Z-axis pulse motor 40A is connected to the end of the Z-axis ball screw 38A. When the Z-axis ball screw 38A is rotated by the Z-axis pulse motor 40A, the Z-axis moving plate 36A moves along the Z-axis guide rails 34A in the Z-axis direction.

[0033] Similarly, the moving unit 24B includes a flat Y-axis moving plate 28B. The Y-axis moving plate 28B is slidably mounted on a pair of Y-axis guide rails 26. A nut portion (not shown) is provided on the back side (rear side) of the Y-axis moving plate 28B. A Y-axis ball screw 30B, which is positioned along the Y-axis direction between the pair of Y-axis guide rails 26, is screwed into this nut portion. A Y-axis pulse motor (not shown) that rotates the Y-axis ball screw 30B is connected to the end of the Y-axis ball screw 30B. When the Y-axis ball screw 30B is rotated by the Y-axis pulse motor, the Y-axis moving plate 28B moves along the Y-axis guide rails 26 in the Y-axis direction.

[0034] A pair of Z-axis guide rails 34B are fixed to the front surface of the Y-axis moving plate 28B along the Z-axis direction. A flat Z-axis moving plate 36B is slidably mounted on the pair of Z-axis guide rails 34B. A nut portion (not shown) is provided on the back surface of the Z-axis moving plate 36B. A Z-axis ball screw 38B, which is positioned between the pair of Z-axis guide rails 34B along the Z-axis direction, is screwed into this nut portion. A Z-axis pulse motor 40B is connected to the end of the Z-axis ball screw 38B. When the Z-axis ball screw 38B is rotated by the Z-axis pulse motor 40B, the Z-axis moving plate 36B moves along the Z-axis guide rails 34B in the Z-axis direction.

[0035] A cutting unit 42A for cutting the workpiece 11 is fixed to the lower end of the Z-axis moving plate 36A. Similarly, a cutting unit 42B for cutting the workpiece 11 is fixed to the lower end of the Z-axis moving plate 36B. Each of the cutting units 42A and 42B is equipped with a cylindrical spindle 44 (see Figure 3) arranged along the Y-axis direction, and an annular cutting blade 46 (see Figure 3) is attached to the tip of the spindle 44.

[0036] As the cutting blade 46, for example, a hub-type cutting blade (hub blade) is used. The hub blade comprises an annular base made of a metal such as an aluminum alloy, and an annular cutting edge formed along the outer edge of the base. The cutting edge of the hub blade is made of an electroformed grinding wheel containing abrasive grains made of diamond, cubic boron nitride (cBN), etc., and a binder such as a nickel plating layer that fixes the abrasive grains.

[0037] However, a washer-type cutting blade (washer blade) can also be used as the cutting blade 46. A washer blade consists only of an annular cutting edge containing abrasive grains and a binder made of metal, ceramics, resin, etc., which fixes the abrasive grains in place.

[0038] The workpiece 11 is cut by cutting the cutting blade 46 mounted on the cutting unit 42A or cutting unit 42B into the workpiece 11 held by the chuck table 10. The cutting blade 46 is also dressed (shaped) by cutting the dressing board 23 held by the chuck table 20A with the cutting blade 46 mounted on the cutting unit 42A. Similarly, the cutting blade 46 is dressed (shaped) by cutting the dressing board 23 held by the chuck table 20B with the cutting blade 46 mounted on the cutting unit 42B.

[0039] An imaging unit 48 is provided adjacent to the cutting unit 42A. The imaging unit 48 is equipped with an image sensor such as a CCD (Charged-Coupled Devices) sensor or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor, and captures images of the workpiece 11 held by the chuck table 10 and the dress board 23 held by the chuck tables 20A and 20B. There are no restrictions on the type of imaging unit 48; for example, a visible light camera or an infrared camera can be used. The images acquired by the imaging unit 48 are used for alignment between the workpiece 11 and the cutting blade 46, and between the dress board 23 and the cutting blade 46, etc.

[0040] A circular opening 4c is provided to the side of the opening 4b. Inside the opening 4c is a cleaning unit 50 for cleaning the workpiece 11. The cleaning unit 50 includes a spinner table 52 that holds and rotates the workpiece 11, and a nozzle 54 that supplies cleaning liquid (cleaning solution) to the workpiece 11 held by the spinner table 52.

[0041] The upper surface of the spinner table 52 is a flat surface that is generally parallel to the horizontal plane (XY plane) and constitutes a holding surface 52a for holding the workpiece 11. The holding surface 52a is connected to a suction source (not shown), such as an ejector, via a flow path (not shown), a valve (not shown), etc., provided inside the spinner table 52. The spinner table 52 is also connected to a rotational drive source (not shown), such as a motor, which rotates the spinner table 52 around a rotation axis that is generally parallel to the Z-axis direction.

[0042] The nozzle 54 supplies cleaning fluid toward the holding surface 52a of the spinner table 52. As the cleaning fluid, a liquid such as pure water or a mixed fluid containing a liquid (such as pure water) and a gas (such as air) can be used.

[0043] The workpiece 11 processed by the cutting units 42A and 42B is transported to the spinner table 52 by a transport unit (not shown) and placed on the holding surface 52a of the spinner table 52 via the sheet 21. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 52a, the workpiece 11 is held by the spinner table 52 via the sheet 21. Then, by supplying cleaning fluid from the nozzle 54 toward the workpiece 11 while rotating the spinner table 52, the workpiece 11 is cleaned.

[0044] A cover 56 is provided on the upper side of the base 4 to cover the components mounted on the base 4. In Figure 1, the outline of the cover 56 is shown by a dashed line.

[0045] A display unit (display device) 58 is provided on the side of the cover 56 to display various information related to the cutting device 2. For example, a touch panel display is used as the display unit 58. In this case, the display unit 58 also functions as an input unit (input device) for inputting various information into the cutting device 2, and the operator can input information such as machining conditions into the cutting device 2 by touching the display unit 58. In other words, the display unit 58 functions as a user interface.

[0046] An information unit (notification device) 60 is provided on the upper part of the cover 56 to notify the operator of information. For example, an indicator light (warning light) may be provided as the information unit 60. When an abnormality occurs in the cutting device 2, the indicator light will light up or flash to notify the operator of the abnormality. Alternatively, a speaker that notifies the operator of information by sound or voice may be used as the information unit 60. In this case, when an abnormality occurs in the cutting device 2, the speaker will emit a sound or voice to notify the operator of the abnormality.

[0047] Furthermore, the cutting device 2 includes a control unit (control device) 62 connected to the components that make up the cutting device 2 (cassette support base 6, chuck table 10, moving unit 12, clamp 18, cutting units 42A, 42B, moving units 24A, 24B, imaging unit 48, cleaning unit 50, display unit 58, notification unit 60, etc.). The control unit 62 operates the cutting device 2 by generating and outputting control signals that control the operation of each component of the cutting device 2.

[0048] For example, the control unit 62 is composed of a computer and includes a calculation unit that performs calculations necessary for the operation of the cutting device 2, and a storage unit that stores various information (data, programs, etc.) used for the operation of the cutting device 2. The calculation unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memory such as ROM (Read Only Memory) and RAM (Random Access Memory).

[0049] Figure 3 is a partial cross-sectional front view showing the cutting device 2 that cuts the workpiece 11. The following description will focus on the case where the workpiece 11 is cut by the cutting unit 42A, but the operation is similar when the workpiece 11 is cut by the cutting unit 42B.

[0050] When cutting the workpiece 11, the workpiece 11 is first held by the chuck table 10. For example, the workpiece 11 is placed on the chuck table 10 such that the front surface 11a is exposed upwards and the back surface 11b (sheet 21 side) faces the holding surface 10a. The frame 19 is also fixed by multiple clamps 18. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 10a, the workpiece 11 is held by the chuck table 10 through the sheet 21.

[0051] Next, the workpiece 11 is cut along the planned division line 13 with the cutting blade 46. Specifically, first, the chuck table 10 is rotated to align the length of the predetermined planned division line 13 with the X-axis direction. The position of the cutting unit 42A in the Y-axis direction is also adjusted so that the cutting blade 46 is positioned on the extension of the predetermined planned division line 13. Furthermore, the height of the cutting unit 42A is adjusted so that the lower end of the cutting blade 46 is positioned below the back surface 11b (upper surface of the sheet 21) of the workpiece 11. The difference in height between the surface 11a of the workpiece 11 and the lower end of the cutting blade 46 corresponds to the depth of cut by the cutting blade 46 into the workpiece 11.

[0052] Then, while rotating the cutting blade 46, the chuck table 10 is moved along the X-axis. This causes the chuck table 10 and the cutting blade 46 to move relative to each other along the X-axis (machining feed), and the cutting blade 46 cuts into the workpiece 11 along the division line 13. As a result, the workpiece 11 is cut and divided along the division line 13.

[0053] During the cutting of the workpiece 11, a liquid such as pure water (cutting fluid) is supplied to the workpiece 11 and the cutting blade 46. This cools the workpiece 11 and the cutting blade 46, and washes away the debris (machining chips) generated by cutting the workpiece 11.

[0054] Subsequently, the same procedure is repeated to cut the workpiece 11 along the other division lines 13. Once the workpiece 11 has been cut along all the division lines 13, the workpiece 11 is divided into multiple device chips, each containing a device 15 (see Figure 2).

[0055] Furthermore, if a structure 17 is formed on the planned division line 13 (see Figure 2), the cutting blade 46 will cut the workpiece 11 along the planned division line 13, including the structure 17. At this time, contact between the cutting blade 46 and the structure 17 can accelerate wear and clogging of the cutting blade 46, leading to a deterioration in the condition of the cutting blade 46. As a result, while the cutting blade 46 is cutting the workpiece 11 along the planned division line 13 where the structure 17 is formed, processing defects such as sudden chipping may occur in the workpiece 11.

[0056] Furthermore, even if no significant machining defects occur on the division line 13 where the structure 17 is formed, the cutting blade 46 is in a deteriorated condition after cutting the structure 17. If the workpiece 11 is cut along another division line 13 with a cutting blade 46 in such a condition, machining defects are likely to occur even if no structure 17 is formed on that division line 13.

[0057] Therefore, in this embodiment, the cutting blade 46 is dressed (shaped) before cutting the workpiece 11 along a specific division line 13 with the cutting blade 46. This allows the workpiece 11 to be cut along the specific division line 13 with a cutting blade 46 in good condition, thereby suppressing the occurrence of machining defects when cutting the workpiece 11 along the specific division line 13.

[0058] Furthermore, in this embodiment, after cutting the workpiece 11 along a specific division line 13 with the cutting blade 46, the cutting blade 46 is dressed (shaped). This allows the condition of the cutting blade 46, which may have deteriorated when cutting the workpiece 11 along a specific division line 13, to be restored, and then the workpiece 11 can be cut along the next division line 13. As a result, the occurrence of machining defects when cutting the workpiece 11 along division lines 13 other than the specific division line 13 is suppressed.

[0059] The following describes a specific example of the workpiece cutting method according to this embodiment. In the following description, as a representative example, we will explain the case in which the cutting blade 46 mounted on the cutting unit 42A is cut into the dressing board 23 held by the chuck table 20A to dress the cutting blade 46. However, the procedure is the same when the cutting blade 46 mounted on the cutting unit 42B is cut into the dressing board 23 held by the chuck table 20B to dress the cutting blade 46.

[0060] Figure 4 is a flowchart illustrating the cutting method for a workpiece. When cutting the workpiece 11 with the cutting device 2, first, a specific dividing line 13 is selected from among a plurality of dividing lines 13 set on the workpiece 11 (dividing line selection step S1). In the dividing line selection step S1, a dividing line 13 that is likely to worsen the condition of the cutting blade 46 is selected from among the plurality of dividing lines 13, for example, a dividing line 13 on which a predetermined structure is formed.

[0061] Figure 5 is a plan view showing the workpiece 11. The multiple division lines 13 set on the workpiece 11 can be classified into a first division line (first street) 13A where a structure 17 is formed, and a second division line (second street) 13B where no structure 17 is formed. For example, the structure 17 is a TEG. The first division line 13A where the TEG is formed is selected as a specific division line 13, while the second division line 13B where the TEG is not formed is not selected as a specific division line 13.

[0062] As shown in Figure 1, the control unit 62 of the cutting device 2 includes a selected line information storage unit 64 that stores information (selected line information) indicating the selected division line 13. The display unit 58 displays an image acquired by imaging the surface 11a side of the workpiece 11 with the imaging unit 48.

[0063] The operator of the cutting device 2 checks the image of the workpiece 11 displayed on the display unit 58 and classifies the multiple planned division lines 13 set on the workpiece 11 into either the first planned division line 13A or the second planned division line 13B. Then, the operator operates the display unit 58 (touch panel display) to input the line number indicating the first planned division line 13A, etc., as selected line information to the cutting device 2. The selected line information is input to the control unit 62 and stored in the selected line information storage unit 64.

[0064] However, the selection of the division lines 13 may be performed automatically. For example, the control unit 62 performs image processing on the captured image acquired by the imaging unit 48 to determine the presence or absence of structures 17 on each division line 13, and classifies the multiple division lines 13 into either the first division line 13A or the second division line 13B. Subsequently, the control unit 62 stores the line number of the first division line 13A, etc., as selected line information in the selected line information storage unit 64.

[0065] Furthermore, there are no restrictions on the method for selecting the division line 13. For example, among the multiple TEGs formed on the division line 13, one may identify TEGs that are particularly prone to causing crushing or clogging of the cutting blade 46 (TEGs containing a predetermined metal, TEGs having a predetermined structure, etc.), and select the division line 13 on which those specific TEGs are formed as the specific division line 13.

[0066] Next, following the procedure described above, the workpiece 11 is sequentially cut along multiple planned division lines 13 with the cutting blade 46 to divide it (see Figure 3). However, the cutting blade 46 is dressed when the next planned division line 13 to be cut becomes the planned division line 13 selected in the planned division line selection step S1, that is, the specific planned division line 13 indicated by the selected line information stored in the selected line information storage unit 64 (see Figure 1).

[0067] Specifically, the cutting blade 46 is dressed by cutting into the dressing board 23 (first dressing step S2). Figure 6(A) is a partial cross-sectional front view showing the cutting apparatus 2 in the first dressing step S2.

[0068] In the first dressing step S2, the cutting blade 46 mounted on the cutting unit 42A is made to cut into the dressing board 23 held by the chuck table 20A. For example, the dressing board 23 is a plate-shaped member formed in a rectangular shape in plan view, and has a surface (first surface) 23a and a back surface (second surface) 23b that are generally parallel to each other. The dressing board 23 also includes abrasive grains made of green carborundum (GC), white alundum (WA), etc., and a binder such as a resin bond or vitrified bond that fixes the abrasive grains. However, there are no restrictions on the shape, material, etc. of the dressing board 23.

[0069] The upper surface of the chuck table 20A is a flat surface that is generally parallel to the horizontal plane (XY plane) and constitutes a rectangular holding surface 20a that holds the dress board 23. The holding surface 20a is connected to a suction source (not shown), such as an ejector, via a flow path (not shown), a valve (not shown), etc., formed inside the chuck table 20A.

[0070] For example, the dress board 23 is placed on the chuck table 20A such that its front surface 23a is exposed upwards and its back surface 23b faces the holding surface 20a. At this time, the orientation (angle) of the dress board 23 is adjusted so that two sides are aligned with the X-axis direction and the other two sides are aligned with the Y-axis direction. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 20a, the dress board 23 is held in place by suction from the chuck table 20A.

[0071] In the first dressing step S2, the cutting unit 42A is first moved along the Y-axis to align the dressing board 23 and the cutting blade 46 in the Y-axis direction. The cutting unit 42A is also moved along the Z-axis to position the lower end of the cutting blade 46 below the surface 23a of the dressing board 23.

[0072] Next, the chuck table 20A is moved along the X-axis while the cutting blade 46 is rotated. This causes the dress board 23 and the cutting blade 46 to move relative to each other along the X-axis, and the tip of the cutting blade 46 cuts into the surface 23a side of the dress board 23. As a result, the tip of the cutting blade 46 comes into contact with the dress board 23 and wears down. In addition, a groove 23c (see Figure 6(C)) is formed on the surface 23a side of the dress board 23 along the X-axis.

[0073] When the tip of the rotating cutting blade 46 comes into contact with the dressing board 23, a phenomenon called self-sharpening is promoted, in which abrasive grains exposed from the binder detach and abrasive grains embedded inside the binder become newly exposed. As a result, abrasive grains that have become clogged from cutting the workpiece 11 detach from the binder, and new abrasive grains become exposed from the binder. In addition, machining debris adhering to the tip of the cutting blade 46 is removed by the wear of the binder, and clogging of the abrasive grains is resolved. As a result, the cutting ability of the cutting blade 46 is restored, and the condition of the cutting blade 46 is improved.

[0074] Furthermore, there is no limit to the number of times the cutting blade 46 can cut into the dressing board 23 in the first dressing step S2. In other words, depending on the material and condition of the cutting blade 46, the cutting blade 46 may cut into the dressing board 23 multiple times.

[0075] Next, the workpiece 11 is cut along a specific division line 13 with the cutting blade 46 (cutting step S3). In cutting step S3, the workpiece 11 is cut along the specific division line 13 (the first division line 13A on which the structure 17 is formed) with the cutting blade 46, which has been prepared by the first dressing step S2. Figure 6(B) is a partial cross-sectional front view showing the cutting apparatus 2 in cutting step S3.

[0076] Specifically, first, the position of the cutting unit 42A in the Y-axis direction is adjusted so that the cutting blade 46 is positioned on the extension of the first planned division line 13A. Also, the height of the cutting unit 42A is adjusted so that the lower end of the cutting blade 46 is positioned below the back surface 11b of the workpiece 11 (the upper surface of the sheet 21). Then, while rotating the cutting blade 46, the chuck table 10 is moved along the X-axis direction. As a result, the chuck table 10 and the cutting blade 46 move relative to each other along the X-axis direction, and the cutting blade 46 cuts into the workpiece 11 along the first planned division line 13A.

[0077] When the cutting blade 46 is driven into the workpiece 11 along the first planned division line 13A, the workpiece 11 is cut together with the structure 17 (see Figure 5). At this time, the cutting blade 46 comes into contact with the structure 17, which accelerates the dulling and clogging of the cutting blade 46. Therefore, while the cutting blade 46 is cutting the workpiece 11 along the first planned division line 13A, the condition of the cutting blade 46 deteriorates, and the workpiece 11 tends to be prone to sudden chipping and other machining defects.

[0078] However, in cutting step S3, the workpiece 11 is cut with the cutting blade 46 immediately after its condition has been adjusted by the first dressing step S2. That is, the workpiece 11 is not cut along the planned division line 13 with the cutting blade 46 after the first dressing step S2 and before the cutting step S3. In this way, by performing cutting step S3 immediately after the first dressing step S2, the workpiece 11 and the structure 17 are cut with the cutting blade 46, whose cutting ability has been restored and which is in good condition. This suppresses the occurrence of machining defects when the workpiece 11 is cut along the first planned division line 13A with the cutting blade 46.

[0079] In cutting step S3, the cutting blade 46 cuts the workpiece 11 along one planned first division line 13A only once. In other words, the cutting blade 46 does not continuously cut the workpiece 11 along two or more planned first division lines 13A. This interrupts the cutting of the workpiece 11 before the condition of the cutting blade 46 deteriorates.

[0080] Next, the cutting blade 46 is dressed by cutting into the dressing board 23 (second dressing step S4). Figure 6(C) is a partial cross-sectional front view showing the cutting apparatus 2 in the second dressing step S4.

[0081] In the second dressing step S4, the cutting blade 46 mounted on the cutting unit 42A is cut into the dressing board 23 held by the chuck table 20A using the same procedure as in the first dressing step S2. This dresses the cutting blade 46, promoting self-sharpening and eliminating dullness and clogging. As a result, the cutting ability of the cutting blade 46 is restored and the condition of the cutting blade 46 is improved.

[0082] When the same dressing board 23 is used in the first dressing step S2 and the second dressing step S4, the positional relationship between the dressing board 23 and the cutting blade 46 is adjusted so that the cutting blade 46 cuts into the area of ​​the dressing board 23 where the groove 23c is not formed. However, it is also possible to use different dressing boards 23 in the first dressing step S2 and the second dressing step S4.

[0083] The second dressing step S4 is performed immediately after the workpiece 11 has been cut in one line with the cutting blade 46 in the cutting step S3. That is, the workpiece 11 is not cut along the division line 13 with the cutting blade 46 after the cutting step S3 and before the second dressing step S4. By performing the second dressing step S4 immediately after the cutting step S3 in this way, the cutting ability of the cutting blade 46 that cut the structure 17 in the cutting step S3 can be quickly restored, and the condition of the cutting blade 46 can be maintained in good condition. This suppresses the occurrence of machining defects when the workpiece 11 is cut along other division lines 13 thereafter.

[0084] Subsequently, the workpiece 11 is cut along the other division lines 13 by repeating the same procedure. When cutting the workpiece 11 along a specific division line 13 (first division line 13A) indicated by the selection line information stored in the selection line information storage unit 64 (see Figure 1), the first dressing step S2, cutting step S3, and second dressing step S4 are performed in order. Once the workpiece 11 has been cut along all the division lines 13, the workpiece 11 is divided into multiple device chips.

[0085] The machining of the workpiece 11 by the cutting device 2 is controlled by the control unit 62 of the cutting device 2 (see Figure 1). Specifically, the control unit 62 monitors the division line 13 that will be machined next. When the division line 13 to be cut next matches the specific division line 13 indicated by the selection line information stored in the selection line information storage unit 64, the control unit 62 outputs control signals to each component of the cutting device 2, causing the cutting device 2 to perform the first dressing step S2, cutting step S3, and second dressing step S4 described above.

[0086] Furthermore, the memory of the control unit 62 stores a program that describes a series of operations of the components of the cutting device 2 necessary to sequentially perform the first dressing step S2, cutting step S3, and second dressing step S4 described above. When the cutting device 2 is to process the workpiece 11, the control unit 62 reads the program from the memory and executes it, and sequentially outputs control signals to each component of the cutting device 2. In this way, the operation of the cutting device 2 is controlled, and the workpiece cutting method according to this embodiment is carried out automatically.

[0087] As described above, in the workpiece cutting method according to this embodiment, the cutting blade 46 is dressed by cutting into the dressing board 23 before cutting the workpiece 11 along a specific division line 13 with the cutting blade 46. This allows the workpiece 11 to be cut along the specific division line 13 with a cutting blade 46 in good condition, and suppresses the occurrence of processing defects when cutting the workpiece 11 along the specific division line 13.

[0088] Furthermore, in the workpiece cutting method according to this embodiment, after cutting the workpiece 11 along a specific division line 13 with the cutting blade 46, the cutting blade 46 is dressed by cutting into the dressing board 23. This allows the workpiece 11 to be cut along other division lines 13 with a cutting blade 46 in good condition, thereby suppressing the occurrence of processing defects when cutting the workpiece 11 along other division lines 13.

[0089] Furthermore, if the condition of the cutting blade 46 is unlikely to deteriorate when cutting the workpiece 11 along a specific division line 13 with the cutting blade 46, the second dressing step S4 may be omitted, and the workpiece 11 may be cut along other division lines 13 immediately following the cutting step S3 with the cutting blade 46. Also, if the condition of the cutting blade 46 is unlikely to deteriorate unless the workpiece 11 is cut along a specific division line 13 with the cutting blade 46, the first dressing step S2 may be omitted.

[0090] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the objectives of the present invention. [Explanation of Symbols]

[0091] 11 Workpiece 11a Surface (first side) 11b Back side (2nd side) 13 planned division lines (street) 13A First planned division line (First Street) 13B Second planned division line (Second Street) 15 devices 17 Structures 19 frames 19a aperture 21 sheets 23 Dressboard 23a Surface (first side) 23b Back side (2nd side) 23c groove 2 Cutting equipment 4 base 4a,4b,4c opening 6 Cassette Support Stands 8 cassettes 10. Chuck table (holding table) 10a Holding surface 12 Mobile Units 14 Table Covers 16 Dustproof and splashproof cover 18 clamps 20A, 20B Chuck Table (Sub-Chuck Table) 20a Holding surface 22 Support structure 24A, 24B Mobile Unit 26 Y-axis guide rail 28A, 28B Y-axis moving plate 30A, 30B Y-axis ball screw 32 Y-axis pulse motor 34A, 34B Z-axis guide rail 36A, 36B Z-axis movement plate 38A, 38B Z-axis ball screw 40A, 40B Z-axis pulse motor 42A, 42B Cutting Unit 44 spindles 46 cutting blades 48 Imaging Units 50 Washing Units 52 Spinner Table 52a Holding surface 54 nozzles 56 Cover 58 Display Unit (Display Device) 60. Notification Department (Notification Unit, Notification Device) 62 Control Unit (Control Device) 64. Selected Line Information Storage Unit

Claims

1. A method for cutting a workpiece using a cutting blade, A division line selection step involves classifying a plurality of division lines set on the workpiece into a first division line on which a predetermined structure is formed and a second division line on which such structure is not formed, and selecting the first division line as a specific division line. A dressing step in which the cutting blade is made to cut into a dressing board, The dressing step is followed by a cutting step in which the cutting blade cuts the workpiece along the specific planned division line, A method for cutting a workpiece, characterized in that, after the dressing step and before the cutting step, the cutting blade does not cut the workpiece along the planned division line.

2. A method for cutting a workpiece using a cutting blade, A division line selection step involves classifying a plurality of division lines set on the workpiece into a first division line on which a predetermined structure is formed and a second division line on which such structure is not formed, and selecting the first division line as a specific division line. A cutting step of cutting the workpiece with the cutting blade along the specific division line, The cutting step is followed by a dressing step of dressing the cutting blade by cutting into a dressing board, A method for cutting a workpiece, characterized in that, after the cutting step and before the dressing step, the cutting blade does not cut the workpiece along the planned division line.

3. A method for cutting a workpiece using a cutting blade, A division line selection step involves classifying a plurality of division lines set on the workpiece into a first division line on which a predetermined structure is formed and a second division line on which such structure is not formed, and selecting the first division line as a specific division line. A first dressing step involves dressing the cutting blade by cutting it into a dressing board, Following the first dressing step, a cutting step is performed in which the workpiece is cut with the cutting blade along the specific planned division line, The cutting step is followed by a second dressing step, in which the cutting blade is dressed by cutting into a dressing board, A method for cutting a workpiece, characterized in that the cutting blade does not cut the workpiece along the planned division line after the first dressing step and before the cutting step, and after the cutting step and before the second dressing step.

4. The method for cutting a workpiece according to any one of claims 1 to 3, characterized in that the structure is TEG.

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