Cutting device

Abstract

To provide a cutting device which can suppress corrosion of a cutting blade.SOLUTION: A cutting device for cutting a work-piece comprises: a chuck table which holds the work-piece; and a cutting unit which includes an annular base, and a cutting edge which contains abrasive grains and a binder for fixing the abrasive grains and is firmed along an outer peripheral edge of the base, and to which a cutting blade is mounted. The cutting unit comprises a spindle, a blade mount attached to a tip of the spindle, and a fixation nut which fixes the cutting blade to the blade mount. The blade mount or the fixation nut is provided with a corrosion layer which comprises a material having an ionization tendency higher than that of a material constituting the binder.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cutting device for cutting a workpiece. [Background technology]

[0002] In the device chip manufacturing process, a wafer is used in which devices are formed in multiple areas partitioned by multiple streets (planned division lines) arranged in a grid pattern. By dividing this wafer along the streets, multiple device chips, each equipped with a device, are obtained. The device chips are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] A cutting device is used to divide the wafers. The cutting device is equipped with a chuck table that holds the workpiece, and a cutting unit that performs cutting on the workpiece. The cutting unit has a built-in spindle, and an annular cutting blade that cuts the workpiece is attached to the tip of the spindle (see Patent Document 1). The cutting blade is rotated and cuts into the wafer held by the chuck table, cutting and dividing the wafer.

[0004] When cutting a workpiece with a cutting device, a liquid (cutting fluid) such as pure water is supplied to the workpiece and the cutting blade. The supply of cutting fluid cools the workpiece and the cutting blade, and washes away debris (cutting debris) generated by cutting. However, pure water has a high resistivity, so when pure water is supplied to the workpiece and the cutting blade as cutting fluid during cutting, static electricity is likely to be generated in the contact area between the cutting blade rotating at high speed and the workpiece. This can cause electrostatic breakdown of devices formed on the workpiece, reducing the yield of device chips.

[0005] Therefore, a method has been proposed in which pure water mixed with carbon dioxide (carbonated water) is used as a cutting fluid (see Patent Documents 2 and 3). Carbonated water has a lower resistivity than pure water, so it is less likely to generate static electricity even when it is supplied to the workpiece and cutting blade during cutting. This suppresses electrostatic damage to devices. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2000-87282 A [Patent Document 2] Japanese Patent Application Publication No. 8-130201 [Patent Document 3] Japanese Patent Application Publication No. 11-300184 Summary of the Invention [Problem to be solved by the invention]

[0007] When cutting a workpiece using a cutting device, if cutting fluid is continuously supplied to the cutting blade, the cutting blade corrodes and wears out due to the cutting fluid. In particular, when pure water (carbonated water) mixed with carbon dioxide is used as the cutting fluid, the corrosion of the cutting blade is likely to progress. As a result, the strength of the cutting blade decreases, and the cutting blade is likely to break or the workpiece is likely to be processed poorly.

[0008] The present invention has been made in consideration of such problems, and has an object to provide a cutting device that can suppress corrosion of the cutting blade. [Means for solving the problem]

[0009] According to one aspect of the present invention, a cutting device for cutting a workpiece includes a chuck table for holding the workpiece, an annular base, and a cutting unit to which a cutting blade is attached, the cutting blade including a cutting edge formed along the outer periphery of the base and including abrasive grains and a binder for fixing the abrasive grains, the cutting unit includes a spindle, a blade mount attached to a tip of the spindle, and a fixing nut for fixing the cutting blade to the blade mount, and the blade mount or the fixing nut is provided with a corrosion layer made of a material having a higher ionization tendency than a material constituting the binder. The binder and the corrosion layer are formed of a nickel plating layer containing sulfur, and the sulfur content of the corrosion layer is higher than the sulfur content of the binder. A cutting device is provided.

[0011] Preferably, , applicable The sulfur content in the corrosion layer is at least 1.2 times the sulfur content in the binder. Effect of the Invention

[0012] In a cutting device according to one aspect of the present invention, a corrosion layer made of a material having a higher ionization tendency than a material constituting a binder of the cutting edge of the cutting blade is provided on one or both of the blade mount and the fixing nut, whereby when cutting fluid is supplied to the cutting blade, the corrosion layer corrodes preferentially as a sacrifice, thereby suppressing corrosion of the cutting edge of the cutting blade. [Brief description of the drawings]

[0013] [Figure 1] FIG. [Diagram 2] FIG. 2(A) is a perspective view showing the cutting unit, and FIG. 2(B) is a perspective view showing the cutting unit with a blade cover attached. [Diagram 3] FIG. 2 is a perspective view showing a blade mount. [Figure 4] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. First, a configuration example of a cutting device 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 (processing feed direction, left-right direction, first horizontal direction) and the Y-axis direction (indexing feed direction, front-back direction, second horizontal direction) are perpendicular to each other. Also, the Z-axis direction (vertical direction, up-down direction, height direction) is perpendicular to the X-axis direction and the Y-axis direction.

[0015] The cutting device 2 includes a base 4 that supports and houses each of the components that make up the cutting device 2. A cover 6 that covers the upper surface side of the base 4 is provided on the upper side of the base 4. A space (machining chamber) in which the workpiece 11 is machined is formed inside the cover 6, and a cutting unit 8 that performs cutting on the workpiece 11 is provided inside the machining chamber.

[0016] An annular cutting blade (electroformed grindstone) 20, which is a tool for cutting the workpiece 11, is attached to the cutting unit 8. In addition, a ball screw type moving mechanism (not shown) that moves the cutting unit 8 along the Y-axis direction and the Z-axis direction is connected to the cutting unit 8.

[0017] A chuck table (holding table) 10 that holds the workpiece 11 is provided below the cutting unit 8. The upper surface of the chuck table 10 is a flat surface that is approximately parallel to the horizontal direction (XY plane direction) and constitutes a holding surface 10a that holds 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, etc. formed inside the chuck table 10.

[0018] A ball screw type moving mechanism (not shown) that moves the chuck table 10 along the X-axis direction is connected to the chuck table 10. In addition, a rotation drive source (not shown) such as a motor that rotates the chuck table 10 around a rotation axis that is approximately parallel to the Z-axis direction is connected to the chuck table 10.

[0019] A cassette mounting table 12 is installed at a front corner of the base 4. A cassette 14 capable of accommodating a plurality of workpieces 11 is mounted on the upper surface of the cassette mounting table 12. A lifting mechanism (not shown) that moves (lifts) the cassette mounting table 12 along the Z-axis direction is connected to the cassette mounting table 12. The height (position in the Z-axis direction) of the cassette 14 is adjusted by the lifting mechanism so that the workpieces 11 can be appropriately carried out from and into the cassette 14.

[0020] For example, the workpiece 11 is a disk-shaped wafer made of a semiconductor material such as silicon, and has a front surface and a back surface that are generally parallel to each other. The workpiece 11 is divided into a plurality of rectangular regions by a plurality of streets (planned division lines) arranged in a lattice pattern so as to intersect with each other. Furthermore, devices such as ICs (Integrated Circuits), LSIs (Large Scale Integration), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) devices are formed on the front surface side of each of the regions divided by the streets. When the cutting device 2 cuts and divides the workpiece 11 along the streets, a plurality of device chips each equipped with a device are manufactured.

[0021] However, there are no limitations on the material, shape, structure, size, etc. of the workpiece 11. For example, the workpiece 11 may be a wafer (substrate) made of a semiconductor other than silicon (GaAs, InP, GaN, SiC, etc.), sapphire, glass (quartz glass, borosilicate glass, etc.), resin, ceramics, metal, etc. In addition, there are no limitations on the type, number, shape, structure, size, arrangement, etc. of devices, and the workpiece 11 does not need to have devices formed thereon. Furthermore, the workpiece 11 may be a package substrate such as a CSP (Chip Size Package) substrate or a QFN (Quad Flat Non-leaded package) substrate.

[0022] When the workpiece 11 is processed by the cutting device 2, the workpiece 11 is supported by an annular frame 13 for ease of handling (transporting, holding, etc.) the workpiece 11. The frame 13 is made of a metal such as SUS (stainless steel), and a circular opening is provided in the center of the frame 13, penetrating the frame 13 in the thickness direction. The diameter of the opening of the frame 13 is larger than the diameter of the workpiece 11, and the workpiece 11 is placed inside the opening of the frame 13.

[0023] Tape 15 is attached to workpiece 11 and frame 13. Tape 15 includes a film-like substrate formed into a circular shape and an adhesive layer (glue layer) provided on the substrate. For example, the substrate 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 be an ultraviolet-curing resin that is cured by irradiation with ultraviolet light.

[0024] When the center portion of the tape 15 is attached to the back surface (lower surface) of the workpiece 11 and the outer periphery of the tape 15 is attached to the frame 13, the workpiece 11 is supported by the frame 13 via the tape 15. Then, the workpiece 11 is housed in the cassette 14 while being supported by the frame 13.

[0025] A transport mechanism (not shown) for transporting the workpiece 11 is provided near the cassette mounting table 12. For example, the transport mechanism includes a plurality of suction pads for suction-holding the upper surface side of the frame 13. The transport mechanism transports the unmachined workpiece 11 from the cassette 14 to the chuck table 10, and also transports the machined workpiece 11 from the chuck table 10 to the cassette 14.

[0026] A display section (display unit) 16 is provided on the front surface 6a side of the cover 6. The display section 16 is composed of various displays, and displays various information related to the cutting device 2. For example, the display section 16 can display an operation screen, a processing status, processing conditions, an image of the workpiece 11, and the like.

[0027] The display unit 16 may be a touch panel display. In this case, the display unit 16 functions as a user interface, and the operator can input information to the cutting device 2 by touching the display unit 16. In other words, the display unit 16 also functions as an input unit (input unit, input device) for inputting information to the cutting device 2. However, the input unit may be provided separately and independently from the display unit 16. In this case, a keyboard, a mouse, etc. can be used as the input unit.

[0028] Each component of the cutting device 2 (cutting unit 8, chuck table 10, cassette mounting table 12, display unit 16, etc.) is connected to a control unit (control unit, control device) 18. The control unit 18 generates control signals that control the operation of each component of the cutting device 2, and controls the operation of the cutting device 2.

[0029] For example, the control unit 18 is configured by a computer. Specifically, the control unit 18 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 is configured to include a processor such as a CPU (Central Processing Unit). In addition, the storage unit is configured to include memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory).

[0030] The workpiece 11 accommodated in the cassette 14 is transported onto the chuck table 10 by a transport mechanism and held by the chuck table 10. For example, the workpiece 11 is placed on the holding surface 10a of the chuck table 10 via a tape 15. In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 10a, the workpiece 11 is sucked and held by the chuck table 10 via the tape 15.

[0031] The workpiece 11 held by the chuck table 10 is machined by the cutting unit 8. Specifically, the cutting unit 8 cuts the workpiece 11 by rotating the cutting blade 20 and cutting into the workpiece 11. During the cutting process, a liquid (cutting fluid) is supplied to the workpiece 11 and the cutting blade 20. The cutting fluid cools the workpiece 11 and the cutting blade 20, and washes away chips (processing chips) generated by the cutting process. Then, the workpiece 11 after processing is transported by a transport mechanism and stored in a cassette 14.

[0032] 2(A) is a perspective view showing the cutting unit 8. An annular cutting blade 20 for cutting the workpiece 11 is attached to the cutting unit 8. The cutting blade 20 includes an annular base 22 and an annular cutting edge 24 formed on the base 22.

[0033] The base 22 is made of a conductive metal (such as an aluminum alloy) and includes a front surface (first surface) 22a, a back surface (second surface) 22b, and an outer periphery (side surface) 22c connected to the front surface 22a and the back surface 22b. A cylindrical opening 22d penetrating the base 22 in the thickness direction is provided in the center of the base 22. In addition, an annular protrusion 22e protruding from the front surface 22a in the thickness direction of the base 22 is provided on the front surface 22a side of the base 22.

[0034] An annular cutting blade 24 is formed along an outer circumferential edge 22c on the back surface 22b side of the base 22. The cutting blade 24 is formed so as to protrude from the outer circumferential edge 22c of the base 22 toward the outside in the radial direction of the base 22.

[0035] The cutting blade 24 includes abrasive grains made of diamond, cubic boron nitride (cBN), or the like, and a binder made of metal or the like for fixing the abrasive grains. For example, the cutting blade 24 is formed by fixing the abrasive grains with nickel electroplated on the outer periphery of the base 22. In this case, the binder of the cutting blade 24 is composed of a nickel plating layer. However, there are no limitations on the material of the abrasive grains, the particle size of the abrasive grains, the material of the binder, and the like, and they are appropriately selected according to the material of the workpiece 11 and the processing conditions.

[0036] The cutting unit 8 includes a housing 30 formed in a hollow cylindrical shape. A cylindrical spindle 32 arranged along the Y-axis direction is accommodated in the housing 30. A tip end (one end side) of the spindle 32 is exposed from the housing 30. A rotation drive source (not shown) such as a motor that rotates the spindle 32 is connected to a base end (the other end side) of the spindle 32.

[0037] A blade mount 34 that supports the cutting blade 20 is attached to the tip of the spindle 32. The blade mount 34 is made of a conductive metal (such as an aluminum alloy) and includes a disk-shaped flange portion 36 and a cylindrical support shaft (boss portion) 38. For example, the blade mount 34 is fixed to the tip of the spindle 32 by a fastener such as a bolt.

[0038] The flange portion 36 includes a front surface (first surface) 36a, a back surface (second surface) 36b, and an outer peripheral edge (side surface) 36c connected to the front surface 36a and the back surface 36b. An annular protrusion 36d that protrudes from the front surface 36a in the thickness direction of the flange portion 36 is provided along the outer peripheral edge 36c on the outer periphery of the flange portion 36. The tip surface of the protrusion 36d is a flat surface that is approximately parallel to the front surface 36a, and constitutes a support surface 36e that supports the cutting blade 20.

[0039] The support shaft 38 is provided so as to protrude from the center of the surface 36a of the flange portion 36, and the center position of the flange portion 36 and the center position of the support shaft 38 generally coincide with each other. In addition, a screw groove 38a is formed on the outer circumferential surface of the support shaft 38.

[0040] An annular fixing nut 40 for fixing the cutting blade 20 to the blade mount 34 is fastened to the thread groove 38a of the support shaft 38. The fixing nut 40 is made of a conductive metal (such as an aluminum alloy) and includes a front surface (first surface) 40a, a back surface (second surface) 40b, and an outer circumferential edge (side surface) 40c connected to the front surface 40a and the back surface 40b. A cylindrical opening 40d is provided in the center of the fixing nut 40, penetrating the fixing nut 40 in the thickness direction. A thread groove corresponding to the thread groove 38a of the support shaft 38 is formed on the inner circumferential surface of the fixing nut 40 exposed inside the opening 40d.

[0041] The cutting blade 20 is mounted on the blade mount 34 so that the support shaft 38 is inserted into the opening 22d. In this state, when the fixing nut 40 is screwed into the thread groove 38a of the support shaft 38 and tightened, the cutting blade 20 comes into contact with the support surface 36e of the flange portion 36 and the back surface 40b of the fixing nut 40, and is sandwiched between the blade mount 34 and the fixing nut 40. As a result, the cutting blade 20 is mounted and fixed to the blade mount 34. Then, the cutting blade 20 rotates around a rotation axis roughly parallel to the Y-axis direction by the power transmitted from the rotation drive source via the spindle 32 and the blade mount 34.

[0042] 2(B) is a perspective view showing the cutting unit 8 to which the blade cover 42 is attached. The cutting blade 20 attached to the cutting unit 8 is covered by the box-shaped blade cover 42 fixed to the housing 30. The blade cover 42 includes a pair of connection parts 44 to which cutting fluid is supplied, and a pair of nozzles 46 connected to the connection parts 44 and disposed to sandwich the lower end part of the cutting blade 20. Each of the pair of nozzles 46 is formed with a supply port (not shown) that opens toward the cutting blade 20.

[0043] The connection part 44 is connected to piping such as tubes and pipes that are a flow path for the cutting fluid. During cutting of the workpiece 11, the cutting fluid supplied to the connection part 44 flows into the nozzle 46 and is supplied from the supply port of the nozzle 46 toward the front and back surfaces of the cutting blade 20. For example, pure water is used as the cutting fluid. In addition, in order to suppress the generation of static electricity during cutting processing, a liquid with a lower resistivity than pure water may be used. For example, pure water mixed with carbon dioxide (carbonated water) may be used as the cutting fluid.

[0044] If the cutting blade 20 is continuously supplied with cutting fluid while cutting the workpiece 11, the cutting edge 24 of the cutting blade 20 is corroded and worn out by the cutting fluid. In particular, if pure water (carbonated water) mixed with carbon dioxide is used, the corrosion of the cutting edge 24 is likely to progress. If the corrosion of the cutting edge 24 occurs, the strength of the cutting edge 24 decreases, and the cutting blade 20 is likely to break or the workpiece 11 is likely to be poorly processed.

[0045] Therefore, in this embodiment, a corrosion layer (sacrificial layer) that causes sacrificial corrosion protection is provided on one or both of the blade mount 34 and the fixing nut 40. As a result, while cutting fluid is being supplied to the cutting blade 20, the corrosion layer corrodes sacrificially first, and corrosion of the binder of the cutting edge 24 is suppressed. As a result, a decrease in the strength of the cutting edge 24 is suppressed.

[0046] 3 is a perspective view showing blade mount 34. A cylindrical opening 34a that opens to rear surface 36b of flange portion 36 is provided in the center of blade mount 34. When blade mount 34 is attached to spindle 32 (see FIG. 2(A)), the tip of spindle 32 is inserted into opening 34a.

[0047] Further, the blade mount 34 is provided with a corrosion layer (sacrificial layer) 50 that causes sacrificial corrosion protection. For example, an annular corrosion layer 50 having a predetermined width is formed on the back surface 36b side of the flange portion 36 so as to surround the opening 34a. However, as long as the corrosion layer 50 is electrically connected to the blade mount 34, there is no limitation on the number, size, shape, position, etc. of the corrosion layer 50. For example, a plurality of corrosion layers 50 may be arranged at approximately equal intervals along the circumferential direction of the flange portion 36 on the back surface 36b side of the flange portion 36. Further, the corrosion layer 50 may be formed on the surface 36a (see FIG. 2(A)), the outer circumferential edge 36c, or the support shaft 38 of the flange portion 36.

[0048] FIG. 4 is a perspective view showing the fixing nut 40. The fixing nut 40 is provided with a corrosion layer (sacrificial layer) 52 that causes sacrificial corrosion protection. For example, a plurality of (four in FIG. 4) arc-shaped corrosion layers 52 having a predetermined width are arranged at approximately equal intervals along the circumferential direction of the fixing nut 40 on the front surface 40a side of the fixing nut 40. However, as long as the corrosion layers 52 are electrically connected to the fixing nut 40, there is no limitation on the number, size, shape, position, etc. of the corrosion layers 52. For example, an annular corrosion layer 52 may be formed continuously along the circumferential direction of the fixing nut 40. The corrosion layer 52 may also be formed on the back surface 40b or the outer circumferential edge 40c of the fixing nut 40.

[0049] When the cutting blade 20 is attached to the blade mount 34 (see FIG. 2(A)), the cutting edge 24 comes into contact with the support surface 36e of the flange portion 36. This electrically connects the bonding material of the cutting edge 24 and the corrosion layer 50 (see FIG. 3) via the flange portion 36. In addition, the base 22 comes into contact with the back surface 40b of the fixing nut 40. This electrically connects the bonding material of the cutting edge 24 and the corrosion layer 52 (see FIG. 4) via the base 22 and the fixing nut 40.

[0050] The corrosion layer 50 (see FIG. 3) is preferably provided in an area other than the area (support surface 36e, see FIG. 2(A)) that comes into contact with the cutting blade 20 when the cutting blade 20 is attached to the blade mount 34. Similarly, the corrosion layer 52 (see FIG. 4) is preferably provided in an area other than the area (rear surface 40b of the fixing nut 40, see FIG. 2(A)) that comes into contact with the cutting blade 20 when the cutting blade 20 is attached to the blade mount 34. In this case, the corrosion layers 50, 52 are less likely to wear or peel off due to contact between the corrosion layers 50, 52 and the cutting blade 20.

[0051] During cutting, cutting fluid is continuously supplied to the cutting blade 20 at a predetermined flow rate, and the cutting blade 20, the blade mount 34, and the fixing nut 40 are exposed to the cutting fluid. Here, the corrosion layers 50, 52 are made of a material that has a higher ionization tendency than the material constituting the binder of the cutting edge 24 of the cutting blade 20. Therefore, while the cutting fluid is being supplied to the cutting blade 20, the corrosion layers 50, 52 corrode preferentially instead of the binder of the cutting edge 24. Specifically, when pure water or the like mixed with carbon dioxide is supplied to the cutting blade 20 as the cutting fluid, metal ions are preferentially dissolved from the corrosion layers 50, 52 rather than the binder of the cutting edge 24, and the corrosion of the corrosion layers 50, 52 progresses. As a result, a sacrificial anticorrosion effect occurs in which the corrosion of the binder of the cutting edge 24 is suppressed by the corrosion of the corrosion layers 50, 52.

[0052] The specific material of the corrosion layers 50, 52 can be appropriately selected depending on the material of the binder of the cutting blade 24. For example, when the binder of the cutting blade 24 is formed of a nickel plating layer, the corrosion layers 50, 52 can be made of metals such as aluminum and zinc, which have a greater ionization tendency than nickel.

[0053] However, the binder of the cutting blade 24 and the corroded layers 50, 52 may be formed using the same material. For example, the binder of the cutting blade 24 and the corroded layers 50, 52 may both be formed of nickel plating layers containing sulfur. In this case, the magnitude of the ionization tendency of the binder of the cutting blade 24 and the corroded layers 50, 52 is controlled by the sulfur content. Specifically, by making the sulfur content of the corroded layers 50, 52 higher than the sulfur content of the binder of the cutting blade 24, the ionization tendency of the corroded layers 50, 52 can be made higher than that of the binder of the cutting blade 24.

[0054] In order to ensure a sufficient difference in ionization tendency between the binder of the cutting blade 24 and the corroded layers 50, 52 and to effectively activate sacrificial protection, it is preferable that the sulfur content in the corroded layers 50, 52 is 1.2 times or more the sulfur content in the binder of the cutting blade 24. For example, the sulfur content in the corroded layers 50, 52 is set to 0.27 mass% or more and 0.33 mass% or less, and the sulfur content in the binder of the cutting blade 24 is set to 0.17 mass% or more and 0.22 mass% or less.

[0055] The method for forming the corroded layers 50, 52 can be appropriately selected depending on the material of the corroded layers 50, 52. For example, when forming a nickel plating layer containing sulfur as the corroded layers 50, 52, a plating tank in which a plating solution is stored is first prepared. As the plating solution, an electrolytic solution containing nickel (nickel sulfate, nickel chloride, nickel sulfamate, etc.) is used. In addition, an additive solution containing sulfur at a predetermined concentration is added to the plating solution. The amount of the additive solution added is adjusted depending on the target value of the sulfur content of the corroded layers 50, 52.

[0056] Next, the blade mount 34 and the fixing nut 40 are immersed in a plating solution. At this time, a mask is formed on the blade mount 34 and the fixing nut 40 to cover areas other than the areas where the corrosion layers 50, 52 are to be formed. Then, a direct current is passed through the plating solution while stirring the plating solution. As a result, nickel is electrodeposited on the blade mount 34 and the fixing nut 40, and nickel plating layers (corrosion layers 50, 52) containing a predetermined amount of sulfur are formed.

[0057] The corrosion layer may be provided on only one of the blade mount 34 and the fixing nut 40. Specifically, when the corrosion layer 50 is provided on the blade mount 34, the corrosion layer 52 can be omitted. Similarly, when the corrosion layer 52 is provided on the fixing nut 40, the corrosion layer 50 can be omitted.

[0058] As described above, in the cutting device according to this embodiment, a corrosion layer made of a material with a higher ionization tendency than the material constituting the binder of the cutting edge 24 of the cutting blade 20 is provided on one or both of the blade mount 34 and the fixing nut 40. As a result, when cutting fluid is supplied to the cutting blade 20, the corrosion layer corrodes preferentially as a sacrifice, and corrosion of the cutting edge 24 of the cutting blade 20 is suppressed.

[0059] The corrosion layers 50, 52 may be provided so as to be embedded in the blade mount 34 and the fixing nut 40. For example, an annular groove is formed on the back surface 36b side of the flange portion 36 of the blade mount 34 so as to surround the opening 34a. The corrosion layer 50 is then formed so as to fill the groove. Similarly, a plurality of arc-shaped grooves are formed on the front surface 40a side of the fixing nut 40 so as to surround the opening 40d. The corrosion layer 52 is then formed so as to fill the groove. This makes it difficult for the corrosion layers 50, 52 to peel off.

[0060] Also, instead of forming the corrosion layers 50, 52, the blade mount 34 and the fixing nut 40 themselves may function as sacrificial anticorrosive members. Specifically, the blade mount 34 and the fixing nut 40 may be made of a material having a higher ionization tendency than the material constituting the binder of the cutting edge 24 of the cutting blade 20. This makes it possible to omit the process of forming the corrosion layers 50, 52 on the blade mount 34 and the fixing nut 40. For example, the blade mount 34 is made of a simple metal selected from iron, chromium, zinc, manganese, aluminum, and zirconium, or an alloy containing at least one of these metals. Also, for example, the fixing nut 40 is made of a simple metal selected from iron, chromium, zinc, manganese, titanium, and zirconium, or an alloy containing at least one of these metals.

[0061] Only one of the blade mount 34 and the fixing nut 40 may be made of a material having a higher ionization tendency than the material constituting the binder of the cutting blade 24. Also, the entire blade mount 34 and the fixing nut 40 may be made of a material having a higher ionization tendency than the material constituting the binder of the cutting blade 24, or only a portion of the blade mount 34 and the fixing nut 40 may be made of a material having a higher ionization tendency than the material constituting the binder of the cutting blade 24.

[0062] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0063] 11 Workpiece 13 Frame 15 Tape 2 Cutting equipment 4 Foundation 6 Cover 6a front 8 Cutting unit 10 Chuck table (holding table) 10a Holding surface 12 Cassette placement table 14 Cassette 16 Display section (display unit, display device) 18 Control section (control unit, control device) 20 Cutting blade (electroformed grinding wheel) 22 Foundation 22a Surface (first side) 22b Back side (2nd side) 22c Outer edge (side) 22d opening 22e Convex part 24 Cutting blade 30 Housing 32 Spindle 34 Blade Mount 34a opening 36 Flange section 36a Surface (first side) 36b Back side (2nd side) 36c Outer edge (side) 36d Convex 36e Support surface 38 Support shaft (boss part) 38a Thread groove 40 Fixing nut 40a Surface (first side) 40b Back side (2nd side) 40c Outer edge (side) 40d opening 42 Blade Cover 44 Connection 46 Nozzles 50 Corrosion layer (sacrificial layer) 52 Corrosion layer (sacrificial layer)

Claims

1. A cutting device for cutting a workpiece, comprising: A chuck table for holding the workpiece; a cutting unit to which a cutting blade is attached, the cutting blade including an annular base and a cutting edge including abrasive grains and a binder for fixing the abrasive grains and formed along the outer periphery of the base; The cutting unit includes a spindle, a blade mount attached to a tip of the spindle, and a fixing nut that fixes the cutting blade to the blade mount; The blade mount or the fixing nut is provided with a corrosion layer made of a material having a higher ionization tendency than the material constituting the bonding material, the binder and the corrosion layer are constituted by a nickel plating layer containing sulfur; The cutting device is characterized in that the sulfur content in the corrosion layer is higher than the sulfur content in the binder.

2. 2. The cutting device according to claim 1, wherein the sulfur content of the corrosion layer is at least 1.2 times the sulfur content of the binder.

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