Method of dressing a dressing plate and a cutting tool

Abstract

The present application provides a dressing plate and a dressing method of a cutting tool, which can perform appropriate dressing of the cutting tool. The dressing plate is used for correction of a shape of the cutting tool, wherein the dressing plate includes: a first layer including first abrasive grains and a first binding material fixing the first abrasive grains; and a plurality of second layers stacked on the first layer in a manner of sandwiching the first layer, a thickness of the first layer being smaller than a width of the cutting tool, the second layer including second abrasive grains having an average particle diameter smaller than the first abrasive grains and a second binding material fixing the second abrasive grains.

Description

Technical Field

[0001] This invention relates to a dressing plate for modifying the shape of a cutting tool used to cut a workpiece, and a method for dressing the cutting tool using the dressing plate. Background Technology

[0002] A wafer containing multiple devices is diced and monolithized to manufacture multiple device chips, each containing a device. These device chips are then mounted onto a predefined substrate, and the mounted chips are encapsulated using a resin-based sealing material (molding resin) to obtain a packaging substrate. This packaging substrate is then diced and monolithized to manufacture multiple packaged devices, each containing multiple packaged device chips. These device chips or packaged devices are then assembled into various electronic devices such as mobile phones and personal computers.

[0003] In the aforementioned slitting of workpieces such as wafers and packaging substrates, a cutting device is used. The cutting device includes a chuck table that holds the workpiece and a cutting unit that performs cutting operations on the workpiece. An annular cutting tool is mounted in the cutting unit. The cutting tool is rotated and cuts into the workpiece held by the chuck table, thereby cutting and slitting the workpiece.

[0004] As a cutting tool continuously cuts the workpiece, the tip of the cutting tool gradually wears down, and the front face of the cutting tool changes into a shape with rounded corners (circular arc (R) shape). Furthermore, when the workpiece is cut into multiple chips using a worn cutting tool, there is a concern that the R shape of the cutting tool may be reflected on the chips, causing chip shape deformation and reducing chip quality.

[0005] Therefore, before cutting the workpiece with a cutting tool, a dressing process is performed to intentionally wear down the tip of the cutting tool to correct its shape. This dressing is performed by holding the tool dressing component (dressing plate) on the chuck table of the cutting device and engaging the cutting tool into the dressing plate. For example, Patent Document 1 discloses a method in which the cutting tool engages with a protrusion formed on the dressing plate, thereby flattening the tip face of the cutting tool.

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-18254

[0007] As described above, when the front end face of the cutting tool is shaped to be flat, a dressing plate with protrusions is used, for example. The dressing plate with protrusions is manufactured by cutting a flat dressing plate with a cutting tool to form multiple linear grooves (recesses) on the front side of the dressing plate. These grooves are formed to a depth greater than the depth to which the cutting tool penetrates the dressing plate during dressing.

[0008] However, when deep grooves are formed on the dressing plate, the rigidity of the dressing plate sometimes decreases, and a stress difference is generated between the front and back sides of the dressing plate, causing warping. In particular, warping is more likely to occur when thin dressing plates are used for material cutting, etc., after grooves are formed. As a result, it is sometimes impossible to hold the dressing plate flat by the chuck table, making it difficult for the cutting tool to accurately cut into the protrusions of the dressing plate. Summary of the Invention

[0009] The present invention was made in view of this problem, and its object is to provide a dressing plate capable of properly dressing cutting tools and a method for dressing cutting tools using the dressing plate.

[0010] According to one aspect of the invention, a dressing plate is provided for modifying the shape of a cutting tool, wherein the dressing plate comprises: a first layer comprising a first abrasive grain and a first bonding material for fixing the first abrasive grain; and a plurality of second layers stacked on the first layer in a manner that clamps the first layer, the thickness of the first layer being less than the width of the cutting tool, the second layers comprising second abrasive grains with an average grain size smaller than the first abrasive grain and a second bonding material for fixing the second abrasive grain.

[0011] Furthermore, it is preferable that the first abrasive grain and the second abrasive grain are green corundum or white corundum, and that the first bonding material and the second bonding material are resin binders. Additionally, it is preferable that the average particle size of the first abrasive grain is 1 μm or more and 200 μm or less, and that the average particle size of the second abrasive grain is 0.1 μm or more and 20 μm or less.

[0012] In addition, according to another aspect of the invention, a dressing plate is provided for use in modifying the shape of a cutting tool, wherein the dressing plate comprises: a first layer containing abrasive grains and a bonding material for fixing the abrasive grains; and a plurality of second layers stacked on the first layer in a manner that clamps the first layer, the thickness of the first layer being less than the width of the cutting tool, and the second layers not containing abrasive grains.

[0013] In addition, according to another aspect of the present invention, a method for dressing a cutting tool is provided, wherein a dressing plate is used to modify the shape of the cutting tool, wherein the dressing plate comprises: a first layer comprising a first abrasive grain and a first bonding material for fixing the first abrasive grain; and a plurality of second layers stacked on the first layer in a manner that clamps the first layer, the thickness of the first layer being less than the width of the cutting tool, the second layer comprising a second abrasive grain with an average grain size smaller than the first abrasive grain and a second bonding material for fixing the second abrasive grain, the method for dressing the cutting tool comprising the following steps: holding the dressing plate by a chuck table such that the exposed surfaces of the first layer and the second layer become the upper surfaces; and moving the cutting tool and the dressing plate relative to each other such that the front end of the cutting tool cuts along the first layer into the upper surface side of the dressing plate, thereby bringing the lower surface of the cutting tool into contact with the first layer and bringing the two sides of the front end of the cutting tool into contact with the second layer, thereby modifying the shape of the front end of the cutting tool.

[0014] In addition, according to another aspect of the present invention, a method for dressing a cutting tool is provided, wherein a dressing plate is used to modify the shape of the cutting tool, wherein the dressing plate comprises: a first layer comprising abrasive grains and a bonding material for fixing the abrasive grains; and a plurality of second layers stacked on the first layer in a manner that clamps the first layer, the thickness of the first layer being less than the width of the cutting tool, and the second layers not containing abrasive grains. The method for dressing the cutting tool comprises the following steps: holding the dressing plate by a chuck table such that the exposed surfaces of the first layer and the second layer become the upper surfaces; and moving the cutting tool and the dressing plate relative to each other such that the front end of the cutting tool cuts along the first layer into the upper surface side of the dressing plate, thereby bringing the lower surface of the cutting tool into contact with the first layer and bringing the two sides of the front end of the cutting tool into contact with the second layer, thereby modifying the shape of the front end of the cutting tool.

[0015] One embodiment of the dressing plate of the present invention comprises: a first layer containing abrasive grains; and a plurality of second layers stacked on the first layer in a manner that clamps the first layer. This allows for dressing of the cutting tool without pre-forming deep grooves on the dressing plate, thereby suppressing warping of the dressing plate. As a result, the dressing plate can be properly held by the chuck table, and the shape of the cutting tool can be appropriately corrected. Attached Figure Description

[0016] Figure 1 This is a three-dimensional view showing the trimming plate.

[0017] Figure 2 (A) is a three-dimensional view showing the first and second layers. Figure 2 (B) is a perspective view showing the alternating layers 1 and 2.

[0018] Figure 3 It is a perspective view showing the trim plate supported by a ring-shaped frame.

[0019] Figure 4 This is a perspective view showing the cutting device.

[0020] Figure 5 This is a partial sectional front view showing the dressing plate held by the chuck table.

[0021] Figure 6 (A) is a partial sectional front view showing the dressing plate and cutting tool during the dressing process. Figure 6 (B) is a front view showing the cutting tool after the dressing process.

[0022] Label Explanation

[0023] 11: Dressing plate; 11a: Dressing plate first side (front of dressing plate); 11b: Dressing plate second side (back of dressing plate); 11c: Dressing plate third side (side of dressing plate); 11d: Dressing plate fourth side (side of dressing plate); 13: First layer; 13a: First layer first side (front of first layer); 13b: First layer second side (back of first layer); 15: Second layer; 15a: Second layer first side (front of second layer); 15b: Second layer second side (back of second layer); 17: Frame; 17a: Opening; 19: Belt; 2: Cutting device; 4: Chuck table (holding table); 4a: Holding surface; 6: Fixture; 8: Cutting unit; 10: Housing; 12: Spindle; 14: Cutting tool; 14a: Lower surface (front end face); 16: Tool cover; 18: Connecting part; 20: Nozzle. Detailed Implementation

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. First, an example of the structure of the dressing plate of this embodiment will be described. The dressing plate of this embodiment is used for shaping (dressing) cutting tools. A cutting tool is a ring-shaped machining tool that cuts into a workpiece to cut the workpiece.

[0025] An example of a workpiece that can be cut by a cutting tool is a disk-shaped silicon wafer. For instance, a silicon wafer is divided into multiple rectangular regions by multiple spacers (pre-defined dividing lines) arranged in a lattice pattern. Furthermore, devices such as ICs (Integrated Circuits), LSIs (Large Scale Integrations), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) are formed within these regions. By cutting the silicon wafer along the spacers with a cutting tool, multiple device chips, each containing a device, are manufactured.

[0026] However, there are no restrictions on the material, shape, structure, or size of the workpiece. For example, the workpiece can be a wafer formed from semiconductors other than silicon (GaAs, InP, GaN, SiC, etc.), glass, ceramics, resin, metal, etc. Furthermore, there are no restrictions on the type, quantity, shape, structure, size, or arrangement of devices formed on the workpiece, and devices may not even be formed on the workpiece. Additionally, the workpiece can be a CSP (Chip Size Package) substrate, a QFN (Quad Flat Non-leaded package) substrate, or other packaging substrates.

[0027] When machining a workpiece using a cutting tool, the first step is to dress the cutting tool. Dressing is performed by rotating the cutting tool and causing its tip to cut into a dressing plate. This causes the tip of the cutting tool to wear against the dressing plate, thereby correcting the shape of the cutting tool's front face.

[0028] Figure 1 This is a perspective view showing the dressing plate 11. The dressing plate 11 is a cuboid component used for dressing cutting tools, comprising multiple first layers 13 and multiple second layers 15. The first layers 13 and second layers 15 are rectangular plate-shaped components that are alternately stacked in the thickness direction of the dressing plate 11 (the thickness direction of the first layers 13 and the second layers 15).

[0029] Layer 13 contains abrasive grains (first abrasive grains) and a bonding material for fixing the abrasive grains (first bonding material). Layer 25 contains abrasive grains (second abrasive grains) and a bonding material for fixing the abrasive grains (second bonding material). Green corundum (GC), white corundum (WA), etc., can be used as the first and second abrasive grains.

[0030] Furthermore, the average particle size of the abrasive grains (second abrasive grains) contained in the second layer 15 is smaller than the average particle size of the abrasive grains (first abrasive grains) contained in the first layer 13. For example, the average particle size of the first abrasive grain is 1 μm or more and 200 μm or less, and the average particle size of the second abrasive grain is 0.1 μm or more and 20 μm or less.

[0031] As the first and second bonding materials, resin binders formed from resin or ceramic binders formed from ceramics can be used. In particular, when resin binders are used as the first and second bonding materials, damage to the cutting tool when it cuts into the dressing plate 11 is suppressed, which is therefore preferred.

[0032] For example, after impregnating abrasive grains into resins such as phenolic resin and epoxy resin, the resin is formed into a plate shape and fired at a specified temperature (e.g., above 150°C and below approximately 200°C), thereby forming plate-shaped first layer 13 and second layer 15. Furthermore, when abrasive grains are included in the first layer 13 and second layer 15, the fluidity of the resin binder decreases, making it easier to maintain the shape of the first layer 13 and second layer 15.

[0033] Figure 2 (A) is a perspective view showing the first layer 13 and the second layer 15. For example, the trimming plate 11 is manufactured by simultaneously cutting the first layer 13 and the second layer 15 after alternatingly stacking large first layers 13 and second layers 15.

[0034] The first layer 13 comprises a first surface (front side) 13a and a second surface (back side) 13b of the first layer, which are generally parallel to each other in a rectangular shape. Similarly, the second layer 15 comprises a second surface (front side) 15a and a second surface (back side) 15b of the second layer, which are generally parallel to each other in a rectangular shape. The second layer 15 is stacked on the first layer 13 in a manner that clamps the first layer 13. Specifically, the second surface 15b of the second layer 15 is fixed to the first surface 13a side of the first layer 13, and the second surface 15a side of the second layer 15 is fixed to the first surface 13b side of the first layer 13. For example, the first layer 13 and the second layer 15 are bonded together by means of an adhesive.

[0035] Figure 2 (B) is a perspective view showing the alternating layers 13 and 25. The layers 13 and 25 are cut off simultaneously by a cutting tool or the like, thereby obtaining a trimmed plate 11 with the desired shape and size.

[0036] Furthermore, there is no limitation on the number of layers 13 and 25 stacked together. However, the top and bottom layers of the dressing plate 11 are the 2nd layer 15. Thus, all layers 13 are sandwiched between layers 25. Additionally, as described later, the 1st layer 13 is used for shaping the tip face of the cutting tool. Therefore, it is preferable that the number of layers 13 is two or more. This allows for multiple shaping of the tip face of the cutting tool using a single dressing plate 11.

[0037] like Figure 1 As shown, the trimming plate 11 includes a trimming plate first surface (front side of the trimming plate) 11a and a trimming plate second surface (back side of the trimming plate) 11b that are generally parallel to each other. The trimming plate first surface 11a corresponds to the second surface 15a of the uppermost second layer 15, and the trimming plate second surface 11b corresponds to the second surface 15b of the lowermost second layer 15.

[0038] Additionally, the trimming plate 11 includes: a pair of trimming plate third surfaces (trimming plate side surfaces) 11c connected to the long sides of the trimming plate first surface 11a and trimming plate second surface 11b; and a pair of trimming plate fourth surfaces (trimming plate side surfaces) 11d connected to the short sides of the trimming plate first surface 11a and trimming plate second surface 11b. The pair of trimming plate third surfaces 11c are rectangular flat surfaces that are substantially parallel to the length direction (length direction of the first layer 13 and the second layer 15) and the thickness direction of the trimming plate 11. Furthermore, the pair of trimming plate fourth surfaces are rectangular flat surfaces that are substantially parallel to the width direction (width direction of the first layer 13 and the second layer 15) and the thickness direction of the trimming plate 11.

[0039] In the third surface 11c and the fourth surface 11d of the trimming plate, the side surfaces of the first layer 13 and the second layer 15 are exposed. Therefore, a periodic striped pattern (horizontal stripe pattern) formed by alternately arranging the side surfaces of the first layer 13 and the second layer 15 is shown on the third surface 11c and the fourth surface 11d of the trimming plate.

[0040] The cutting tool is dressed using the dressing plate 11 described above. When dressing the cutting tool, the dressing plate 11 is first supported by a ring-shaped frame. Figure 3 This is a perspective view showing the trim plate 11 supported by the annular frame 17.

[0041] The frame 17 is formed of a metal such as SUS (stainless steel). A circular opening 17a, extending through the frame 17 in the thickness direction, is provided in the center of the frame 17. Furthermore, the diameter of the opening 17a is greater than the length of each side of the trimming plate 11. The trimming plate 11 is disposed inside the opening 17a.

[0042] A strip 19 is attached to the trimming plate 11 and the frame 17. Specifically, the central portion of the strip 19 is attached to the trimming plate 11, and the outer periphery of the strip 19 is attached to the frame 17. As a result, the trimming plate 11 is supported by the frame 17 by means of the strip 19.

[0043] The element 19 includes a circular, film-like substrate and an adhesive layer (paste layer) disposed on the substrate. For example, the substrate may be formed of a resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate, and the adhesive layer may be formed of an epoxy, acrylic, or rubber-based adhesive. Alternatively, the adhesive layer may be a UV-curing resin that cures upon exposure to ultraviolet light.

[0044] Furthermore, the trimming plate 11 is arranged such that a stripe 19 is attached to one of the third surfaces 11c of the pair of trimming plates. Therefore, the trimming plate 11 is supported by the frame 17 with one of the third surfaces 11c of the pair of trimming plates with a striped pattern facing upwards, while the first surface 11a, the second surface 11b, and the fourth surface 11d of the pair of trimming plates with a striped pattern are exposed to the side.

[0045] The cutting tool is brought into contact with the dressing plate 11 supported by the frame 17, thereby dressing the cutting tool. A cutting device is used in dressing the cutting tool. Figure 4 This is a perspective view showing the cutting device 2. Additionally, in Figure 4 In this diagram, the X-axis (machining feed direction, first horizontal direction) and Y-axis (indexing feed direction, second horizontal direction) are perpendicular to each other. Additionally, the Z-axis (vertical direction, up / down direction, height direction) is perpendicular to both the X-axis and Y-axis.

[0046] The cutting device 2 has a chuck table (holding table) 4 capable of holding the workpiece and the dressing plate 11. The upper surface of the chuck table 4 is a flat surface that is approximately parallel to the horizontal direction (XY plane direction), forming a holding surface 4a (see reference) for holding the workpiece or the dressing plate 11. Figure 5 The retaining surface 4a is connected to an injection source (not shown) via a flow path (not shown), a valve (not shown), etc., formed inside the chuck table 4.

[0047] The chuck table 4 is connected to a ball screw-type moving mechanism (not shown) that moves the chuck table 4 along the X-axis, and a motor or other rotary drive source (not shown) that rotates the chuck table 4 about a rotation axis approximately parallel to the Z-axis. Additionally, multiple clamps 6 are provided around the chuck table 4 to hold and fix the frame 17 (see reference). Figure 5 ).

[0048] Above the chuck table 4 is a cutting unit 8 capable of cutting the workpiece and the dressing plate 11. The cutting unit 8 has a cylindrical housing 10, in which a cylindrical spindle 12 (see reference) arranged along the Y-axis direction is housed. Figure 5 The front end (one end) of the spindle 12 protrudes outside the housing 10, and a rotation drive source such as an electric motor is connected to the base end (the other end) of the spindle 12.

[0049] A ring-shaped cutting tool 14 for cutting the workpiece is mounted at the front end of the spindle 12. The cutting tool 14 rotates about a rotation axis that is approximately parallel to the Y-axis direction by means of power transmitted from the rotary drive source via the spindle 12.

[0050] As the cutting tool 14, for example, a hub-type cutting tool (hub tool) is used. A hub tool is a cutting tool that integrates a ring-shaped base formed of metal or the like and a ring-shaped cutting edge formed along the outer periphery of the base. The cutting edge of the hub tool can be made of an electroformed abrasive, which contains abrasive grains formed of diamond, cubic boron nitride (cBN), etc., and a bonding material such as a nickel plating layer that fixes the abrasive grains.

[0051] However, a washer-type cutting tool (washer tool) can also be used as the cutting tool 14. The washer tool consists only of annular cutting edges, which contain abrasive grains and a bonding material (metal bond, resin bond, ceramic bond, etc.) to fix the abrasive grains.

[0052] When the cutting tool 14 is installed in the cutting unit 8, the cutting tool 14 is covered by a tool cover 16 fixed to the housing 10. The tool cover 16 has a pair of connecting portions 18 connected to a pipe (not shown) for supplying cutting fluid such as pure water; and a pair of nozzles 20 connected to the pair of connecting portions 18. The pair of nozzles 20 are arranged on two side surfaces (front and back sides) of the cutting tool 14 in a manner that clamps the lower end of the cutting tool 14. In addition, each of the pair of nozzles 20 has a supply port (not shown) that opens toward the cutting tool 14.

[0053] When cutting fluid is supplied to a pair of connecting parts 18, the cutting fluid flows into a pair of nozzles 20, and is supplied from the spray nozzles 20 toward the two sides (front and back) of the cutting tool 14. The cutting fluid cools the cutting tool 14 and the workpiece or dressing plate 11 held by the chuck table 4, and washes away the chips (cutting chips) generated due to the cutting process.

[0054] A ball screw-type moving mechanism (not shown) is connected to the cutting unit 8 to move the cutting unit 8. The moving mechanism moves the cutting unit 8 along the Y-axis and moves it up and down along the Z-axis. The position of the indexing feed direction of the cutting tool 14 and the depth of cut of the cutting tool 14 into the workpiece or dressing plate 11 are adjusted by the moving mechanism.

[0055] The cutting device 2 described above cuts the workpiece, such as a silicon wafer. For example, the cutting tool 14 cuts the silicon wafer along the spacer to divide it into multiple device chips.

[0056] Furthermore, as the cutting tool 14 continues to cut the workpiece, the front end of the cutting tool 14 wears down, and the front face of the cutting tool 14 changes into a shape with rounded corners (R shape) (see reference). Figure 5 Furthermore, when the workpiece is cut into multiple chips using the worn cutting tool 14, there is concern that the R-shape of the cutting tool 14 may be reflected on the chips, causing chip shape deformation and reducing chip quality.

[0057] Therefore, before machining the workpiece with the cutting tool 14, a dressing process is performed to intentionally wear down the tip of the cutting tool 14 to correct its shape. The dressing is performed by bringing the cutting tool 14 into the dressing plate 11. Hereinafter, a specific example of a cutting tool dressing method for correcting the shape of the cutting tool 14 using the dressing plate 11 will be described.

[0058] First, the trimming plate 11 is held by the chuck worktable 4 (holding process). Figure 5 This is a partial cross-sectional front view showing the trimming plate 11 held by the chuck table 4.

[0059] During the holding process, the trimming plate 11 supported by the frame 17 is positioned on the holding surface 4a of the chuck table 4, with the belt 19 in between. The frame 17 is secured by multiple clamps 6. When an attractive force (negative pressure) from an attraction source is applied to the holding surface 4a in this state, the trimming plate 11 is attracted and held by the chuck table 4 with the belt 19 in between. Thus, the trimming plate 11 exposes its third surface 11c (refer to the trimming plate third surface 11c) with a striped pattern, exposed along the sides of the first layer 13 and the second layer 15. Figure 1 (etc.) are held in the manner of the upper surface by the chuck table 4.

[0060] Next, the cutting tool 14 is brought into the upper surface of the dressing plate 11, thereby correcting the shape of the front end of the cutting tool 14 (dressing process). Figure 6 (A) is a partial cross-sectional front view showing the dressing plate 11 and the cutting tool 14 in the dressing process.

[0061] In the trimming process, the chuck table 4 is first rotated so that the length direction of the trimming plate 11 (the length direction of the third surface 11c of the trimming plate) is aligned with the X-axis direction. Thus, the trimming plate 11 is configured such that the length direction is along the X-axis direction, the thickness direction is along the Y-axis direction, and the width direction is along the Z-axis direction.

[0062] Additionally, the cutting unit 8 (refer to...) Figure 4 and Figure 5 The cutting tool 14 moves along the Y-axis direction, aligning the first layer 13 of the dressing plate 11 with the Y-axis position of the cutting tool 14. For example, the cutting tool 14 moves along the thickness direction of the first layer 13. Figure 6 The center of the paper in (A) in the left-right direction and the width direction of the cutting tool 14 ( Figure 6 Positioning is performed in a manner that aligns the center of the paper (in the left-right direction) with the Y-axis position. Additionally, the cutting unit 8 (refer to...) is positioned... Figure 4 and Figure 5 Move along the Z-axis and position the lower end of the cutting tool 14 below the upper surface (third surface 11c of the dressing plate) of the dressing plate 11.

[0063] Then, while rotating the cutting tool 14, the chuck table 4 is moved along the X-axis. This causes the dressing plate 11 and the cutting tool 14 to move relative to each other along the machining feed direction, causing the tip of the cutting tool 14 to cut into the upper surface of the dressing plate 11 along the first layer 13. As a result, the upper surface of the dressing plate 11 is cut by the cutting tool 14, forming a straight groove along the first layer 13 on the upper surface of the dressing plate 11. Furthermore, the tip of the cutting tool 14 wears through contact with the dressing plate 11, and the shape of the lower surface (front face) 14a of the cutting tool 14 is corrected.

[0064] Here, the thickness d1 of the first layer 13 is less than the thickness (width) D of the cutting tool 14. Therefore, the lower surface 14a of the cutting tool 14 contacts the first layer 13, which contains large abrasive grains (first abrasive grains), and the two sides of the front end of the cutting tool 14 contact the second layer 15, which contains small abrasive grains (second abrasive grains). Therefore, wear is easier to occur on the lower surface 14a of the cutting tool 14, and less likely to occur on the two sides of the front end of the cutting tool 14.

[0065] Furthermore, the thicknesses of the first layer 13 and the second layer 15 can be appropriately set according to the thickness D of the cutting tool 14. Additionally, the sum of the thickness d2 of the second layer 15 and the thickness d1 of the two first layers holding the second layer 15 (d2+2d1) can be less than the thickness D of the cutting tool 14. In this case, when the cutting tool 14 cuts into the dressing plate 11, the lower surface 14a of the cutting tool 14 contacts two or more first layers 13.

[0066] Figure 6 (B) is a front view showing the cutting tool 14 after the dressing process. When the cutting tool 14 cuts into the dressing plate 11 along the first layer 13 as described above, the area of ​​the front end of the cutting tool 14 that contacts the first layer 13 wears preferentially, and the rounded corners of the lower surface 14a of the cutting tool 14 are gradually eliminated. And when the lower surface 14a of the cutting tool 14 becomes a flat shape, the dressing of the cutting tool 14 is completed.

[0067] Furthermore, the number of times the cutting tool 14 cuts into the dressing plate 11 is appropriately set according to the shape, material, and size of the cutting tool 14. When the cutting tool 14 cuts into the dressing plate 11 multiple times, after the cutting tool 14 cuts into the dressing plate 11 along the first layer 13, the cutting tool 14 is moved in the Y-axis direction and cuts into the dressing plate 11 along the second layer 13. By repeating this operation, the cutting tool 14 can cut into the dressing plate 11 a desired number of times. And, when grooves are formed along all the layers 13, the used dressing plate 11 is replaced with a new dressing plate 11 (unused dressing plate 11).

[0068] As described above, the dressing plate 11 of this embodiment is configured to include: a first layer 13 containing abrasive grains; and a plurality of second layers 15 stacked on the first layer 13 in a manner that clamps the first layer 13. Therefore, the dressing of the cutting tool 14 can be performed without pre-forming a deep groove on the dressing plate 11, thereby suppressing warping of the dressing plate 11. As a result, the dressing plate 11 can be properly held by the chuck table 4, and the shape of the cutting tool 14 can be appropriately corrected.

[0069] Furthermore, in the above embodiment, the case where the second layer 15 contains abrasive grains (second abrasive grains) with an average particle size smaller than that of the first layer 13 was described. However, the second layer 15 can also be a layer that does not contain abrasive grains. In this case, wear is less likely to occur on the two sides of the front end of the cutting tool 14 that is in contact with the second layer 15, and the lower surface 14a of the cutting tool 14 can be easily corrected to a flat shape.

[0070] In addition, the structure and method of the above embodiments can be appropriately modified and implemented as long as they do not depart from the scope of the purpose of the present invention.

Claims

1. A dressing plate used for correcting the shape of a cutting tool, characterized in that, The trimming plate includes: The first layer comprises a first abrasive grain and a first bonding material fixing the first abrasive grain; and Multiple second layers are stacked on top of the first layer in a manner that sandwiches the first layer. The thickness of the first layer is less than the width of the cutting tool. The second layer comprises second abrasive grains with an average particle size smaller than the first abrasive grains and a second bonding material that fixes the second abrasive grains. By having the lower surface of the cutting tool contact the first layer and the two sides of the front end of the cutting tool contact the second layer, the shape of the front end of the cutting tool is modified so that the lower surface of the cutting tool becomes a flat shape.

2. The trimming plate according to claim 1, characterized in that, The first and second abrasive grains are made of green corundum or white corundum. The first bonding material and the second bonding material are resin binders.

3. The trimming plate according to claim 1 or 2, characterized in that, The average particle size of the first abrasive grain is greater than 1 μm and less than 200 μm. The average particle size of the second abrasive grain is greater than 0.1 μm and less than 20 μm.

4. A dressing plate used for correcting the shape of a cutting tool, characterized in that, The trimming plate includes: The first layer comprises abrasive grains and a bonding material that holds the abrasive grains in place; and Multiple second layers are stacked on top of the first layer in a manner that sandwiches the first layer. The thickness of the first layer is less than the width of the cutting tool. This second layer does not contain abrasive particles. By having the lower surface of the cutting tool contact the first layer and the two sides of the front end of the cutting tool contact the second layer, the shape of the front end of the cutting tool is modified so that the lower surface of the cutting tool becomes a flat shape.

5. A method for dressing a cutting tool, comprising using a dressing plate to modify the shape of the cutting tool, characterized in that, The trimming plate includes: The first layer comprises a first abrasive grain and a first bonding material fixing the first abrasive grain; and Multiple second layers are stacked on top of the first layer in a manner that sandwiches the first layer. The thickness of the first layer is less than the width of the cutting tool. The second layer comprises second abrasive grains with an average particle size smaller than the first abrasive grains and a second bonding material that fixes the second abrasive grains. The dressing method for this cutting tool includes the following steps: The trimming plate is held by a chuck table in such a manner that the exposed surfaces of the first and second layers become the upper surfaces; and The cutting tool and the dressing plate are moved relative to each other so that the front end of the cutting tool cuts into the upper surface of the dressing plate along the first layer, thereby making the lower surface of the cutting tool contact the first layer and the two sides of the front end of the cutting tool contact the second layer. The shape of the front end of the cutting tool is modified so that the lower surface of the cutting tool becomes a flat shape.

6. A method for dressing a cutting tool, comprising using a dressing plate to modify the shape of the cutting tool, characterized in that, The trimming plate includes: The first layer comprises abrasive grains and a bonding material that holds the abrasive grains in place; and Multiple second layers are stacked on top of the first layer in a manner that sandwiches the first layer. The thickness of the first layer is less than the width of the cutting tool. This second layer does not contain abrasive particles. The dressing method for this cutting tool includes the following steps: The trimming plate is held by a chuck table in such a manner that the exposed surfaces of the first and second layers become the upper surfaces; and The cutting tool and the dressing plate are moved relative to each other so that the front end of the cutting tool cuts into the upper surface of the dressing plate along the first layer, thereby making the lower surface of the cutting tool contact the first layer and the two sides of the front end of the cutting tool contact the second layer. The shape of the front end of the cutting tool is modified so that the lower surface of the cutting tool becomes a flat shape.

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