Grindstone, grinding wheel, and manufacturing method of grindstone

Abstract

To provide a grindstone that enables a surfactant to be easily added to processing water.SOLUTION: A grindstone includes: an abrasive grain; a binding material fixing the abrasive grain; and a surfactant supply particle contained in the binding material. When water contacts the surfactant supply particle, the surfactant is eluded from the surfactant supply particle into the water. It is preferable that the surfactant supply particle includes as the surfactant any one of an anionic surfactant particle, a cationic surfactant particle, and a nonionic surfactant particle. It is more preferable that the binding material contains a resin as a main component.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a grinding wheel including abrasive grains and a binder for fixing the abrasive grains, and a manufacturing method thereof. The present invention also relates to a grinding wheel including an annular base having an end face on which an annular groove is formed, and a plurality of grinding stones arranged in an annular shape, each having its base end fixed in the annular groove. [Background technology]

[0002] Chips for devices such as integrated circuits (ICs) are essential components in various electronic devices such as mobile phones and personal computers. These chips are manufactured, for example, by thinning a wafer having multiple devices formed on its front surface by grinding it from its back surface, and then cutting and dividing the wafer along the boundaries between the multiple devices.

[0003] A grinding device for grinding a workpiece such as a wafer generally includes a chuck table for holding the workpiece and a spindle with a grinding wheel attached to the tip thereof (see, for example, Patent Document 1). The grinding wheel includes an annular base having an end face on one side of which an annular groove is formed, and a plurality of grinding stones arranged in an annular shape, each of whose base ends is fixed in the annular groove.

[0004] When thinning a workpiece in a grinding device, the workpiece is first held by a chuck table so that its backside is exposed. Then, by rotating both the chuck table and the spindle and bringing them closer together, the bottom surfaces of the grinding wheels, which are the processing surfaces, are pressed against the backside of the workpiece. This allows the workpiece to be ground by the grinding wheels and thinned.

[0005] A cutting device for cutting a workpiece generally includes a chuck table for holding the workpiece and a spindle with a cutting blade attached to the tip thereof. The cutting blade includes a grinding wheel having an annular shape, the outer surface of which serves as the cutting surface.

[0006] When dividing a workpiece in a cutting device, the workpiece is first held by the chuck table. Then, the height of the cutting blade is adjusted so that the lowest point of the grinding stone is slightly lower than the bottom surface of the workpiece. The chuck table and the spindle are moved relative to each other while the spindle is rotated, bringing the grinding stone into contact with the workpiece from the cutting surface. This causes the workpiece to be cut by the cutting blade and divided.

[0007] When a workpiece is processed (for example, by grinding or cutting) in this way, processing debris is generated, and the grinding wheel and the workpiece are heated by frictional heat, which may result in a deterioration in the processing quality of the workpiece. Therefore, such processing is often performed while supplying processing water such as pure water near the contact interface (processing point) between the grinding wheel and the workpiece to wash away processing debris and cool the grinding wheel and the workpiece.

[0008] However, the processing debris generated during the processing of the workpiece may not be sufficiently removed by the pure water and may remain attached to the surface of the workpiece. Therefore, in order to sufficiently suppress the adhesion of processing debris to the workpiece with the processing water, a chemical solution containing a surfactant has been developed that is mixed into the processing water supplied to the workpiece, etc. (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-288881 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-13301 Summary of the Invention [Problem to be solved by the invention]

[0010] However, in order to use the processing water mixed with chemicals in the processing equipment, it is necessary to install a device in the processing equipment that adds a predetermined amount of chemicals to the processing water. Furthermore, it is time-consuming to periodically replenish the device with chemicals. This increases the manufacturing costs of the processing equipment and the processing costs of the workpieces.

[0011] In view of this, the present invention provides a grinding stone that allows a surfactant to be easily added to processing water, a method for manufacturing the grinding stone, and a grinding wheel that includes the grinding stone. [Means for solving the problem]

[0012] According to one aspect of the present invention, there is provided a grinding wheel comprising abrasive grains, a binder for fixing the abrasive grains, and surfactant supply particles contained in the binder, wherein when water comes into contact with the surfactant supply particles, a surfactant is eluted from the surfactant supply particles into the water.

[0013] Preferably, the surfactant supply particles contain anionic surfactant particles, cationic surfactant particles, or nonionic surfactant particles as the surfactant.

[0014] More preferably, the binder contains a resin as a main component.

[0015] Another aspect of the present invention is a grinding wheel characterized by having an annular base with a concave annular groove formed on one end surface, and the grinding stone arranged in the annular groove and fixed to the annular base.

[0016] Or, preferably, the entire structure is annular.

[0017] According to another aspect of the present invention, there is provided a method for manufacturing a grinding wheel, comprising a mixing step of mixing abrasive grains, a binder, and surfactant supply particles to form a mixed material, a molding step of molding the mixed material to obtain a molded body, and a firing step of firing the molded body to obtain a grinding wheel, wherein when water comes into contact with the surfactant supply particles contained in the grinding wheel, surfactant is eluted from the surfactant supply particles into the water.

[0018] Preferably, in the mixed material, the content of the surfactant supply particles relative to the total amount of the binder and the surfactant supply particles is 1 to 10 vol %. [Effects of the Invention]

[0019] A grinding wheel according to one embodiment of the present invention contains surfactant supply particles in a binder. When these surfactant supply particles come into contact with water, the surfactant dissolves in the water. Therefore, when a workpiece is machined with this grinding wheel while supplying processing water to the workpiece, the surfactant dissolves in the processing water. The processing water containing the surfactant prevents chips generated during machining from adhering to the workpiece. Furthermore, the grinding wheel according to one embodiment of the present invention does not require any special device to be incorporated into the processing equipment, and can be used in the same manner as conventional grinding wheels.

[0020] Therefore, one aspect of the present invention provides a grinding stone that allows a surfactant to be easily added to processing water, a method for manufacturing the grinding stone, and a grinding wheel that includes the grinding stone. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 2 is a perspective view schematically showing a grinding device. [Figure 2] FIG. 2 is a perspective view schematically showing the underside of the grinding wheel. [Figure 3] FIG. 2 is a partially enlarged cross-sectional view schematically showing the structure of the grinding wheel. [Figure 4] FIG. 1 is a side view schematically showing a state in which a workpiece is ground with a grinding wheel having a grinding stone. [Figure 5] FIG. 2 is a side view schematically showing a state in which a workpiece is cut. [Figure 6] FIG. 2 is an exploded perspective view schematically showing components of a grinding unit. [Figure 7] FIG. 2 is a cross-sectional view schematically showing a mixing step. [Figure 8] FIG. 8(A) is a cross-sectional view that schematically shows the molding step, and FIG. 8(B) is a cross-sectional view that schematically shows the firing step. [Figure 9] 1 is a flowchart showing the flow of each step of a method for manufacturing a grindstone. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will be described with reference to the accompanying drawings, which are provided to facilitate understanding of the present invention and do not necessarily accurately reflect the objects and / or methods in which the present invention is embodied.

[0023] First, a grinding device, which is an example of a processing device using the grinding wheel according to this embodiment, and a workpiece to be ground by the grinding device will be described. Fig. 1 is a perspective view schematically showing a grinding device (processing device) 2. Fig. 1 shows the simplest example of the configuration of the grinding device 2. Fig. 1 also includes a perspective view schematically showing a workpiece 1.

[0024] The workpiece 1 is a disk-shaped wafer made of a material such as silicon, and has a front surface 1a and a back surface 1b that are generally parallel to each other. A plurality of planned dividing lines (not shown) are set on the front surface 1a of the workpiece 1, and are arranged in a grid pattern so as to intersect with each other. Devices (not shown), such as ICs (Integrated Circuits) and LSIs (Large Scale Integration), are formed in each of the regions defined by the planned dividing lines on the front surface 1a of the workpiece 1.

[0025] There are no limitations on the material, structure, size, shape, etc. of the workpiece 1. For example, the workpiece 1 may be a substrate made of a semiconductor other than silicon (GaAs, InP, GaN, SiC, etc.), sapphire, glass (quartz glass, borosilicate glass, etc.), etc. There are also no limitations on the type, number, shape, structure, size, arrangement, etc. of devices, and the workpiece 1 does not necessarily have to have any devices formed thereon.

[0026] The workpiece 1 is ground from the back surface 1b side to thin it, and then divided along the planned division lines to produce a plurality of thin chips (device chips), each equipped with a device. When the back surface 1b side of the workpiece 1 is ground, a tape-like protective member 3 having a diameter approximately the same as that of the workpiece 1 is attached to the front surface 1a side of the workpiece 1 to protect the front surface 1a side.

[0027] The grinding device 2 has a substantially rectangular parallelepiped base 4 that supports each of the components. A recess 4a is formed on the top surface of the base 4 along the Y-axis direction. The recess 4a is provided with a holding table 6 that is movable in the Y-axis direction and can hold the workpiece 1, and a dust-proof and drip-proof cover 4b that covers the opening of the recess 4a while exposing the holding table 6. A Y-axis movement mechanism (not shown) that movably supports the holding table 6 is disposed inside the recess 4a.

[0028] The holding table 6 has a frame 6a made of a material such as ceramics. A suction path (not shown) is provided inside the frame 6a, and one end of the suction path is connected to a suction source (not shown) such as an ejector or a pump.

[0029] The frame 6a has a recess (accommodation recess) on its upper surface, which is a disk-shaped space. A disk-shaped support 6b is accommodated in this recess, which supports the workpiece 1 on its upper surface. The support 6b is, for example, a porous plate made of a material such as ceramics. The other end of the suction path of the frame 6a is connected to the lower surface of the support 6b. When the suction source is operated, a negative pressure acts on the workpiece 1 placed on the upper surface of the support 6b. In other words, the workpiece 1 is sucked and held on this upper surface. Therefore, the upper surface of the holding table 6 functions as a holding surface 6c.

[0030] The frame 6a of the holding table 6 is supported by a spindle (not shown). A rotary drive source (not shown), such as a motor, is provided at the bottom end of the spindle to rotate the spindle. By operating this rotary drive source, the holding table 6 rotates around a table rotation axis 6d (see FIG. 4) that is perpendicular to the holding surface 6c.

[0031] Returning to Fig. 1, we will continue to explain the grinding device 2. The grinding device 2 includes a grinding unit 8 that grinds the workpiece 1 held by the holding table 6, and a lifting unit (Z-axis movement mechanism) 10 that raises and lowers the grinding unit 8. A support part 12 is erected on the rear side of the grinding device 2, and the grinding unit 8 is supported by this support part 12 via the lifting unit 10.

[0032] A pair of guide rails 14 extending along the Z-axis direction (vertical direction) are provided on the front surface of the support part 12. A movable plate 16 is slidably attached to each guide rail 14. A nut part (not shown) is provided on the back surface side (rear surface side) of the movable plate 16, and a ball screw 18 parallel to the guide rails 14 is screwed into this nut part.

[0033] A pulse motor 20 is connected to one end of the ball screw 18. When the pulse motor 20 rotates the ball screw 18, the movable plate 16 moves in the Z-axis direction along the guide rail 14. A grinding unit 8 is fixed to the front side of the movable plate 16. By moving the movable plate 16, the grinding unit 8 can move in the Z-axis direction (processing feed direction). The grinding unit 8 has a cut cylindrical holding member 22. The holding member 22 is fixed to the surface on the front side of the movable plate 16.

[0034] A spindle housing 24 is provided inside the holding member 22. The spindle housing 24 is supported on the bottom surface of the holding member 22. A portion of a spindle 26 is rotatably housed in the spindle housing 24. A rotational drive source (not shown), such as a motor, is connected to the upper end of the spindle 26. When the rotational drive source is operated, the spindle 26 rotates around a wheel rotation axis 26a (see FIG. 4).

[0035] The lower end of the spindle 26 is located below the bottom of the holding member 22. The upper surface of a disk-shaped wheel mount 28 is connected to the lower end of the spindle 26. A grinding wheel 30 is attached to the lower surface of the wheel mount 28. The grinding wheel 30 includes a grinding wheel according to this embodiment. The grinding wheel 30 is one mode of use of the grinding wheel according to this embodiment.

[0036] 2 is a perspective view schematically showing the underside of the grinding wheel 30. The grinding wheel 30 has an annular base 32 with a concave annular groove 32d formed in one end face (lower face 32b). The annular base 32 is made of a metal such as aluminum or a resin, and has a diameter corresponding to the diameter of the workpiece 1. The upper face 32a of the annular base 32 is connected to the lower face of the wheel mount 28. In other words, the grinding wheel 30 is attached to the spindle 26 via the wheel mount 28.

[0037] An opening 32c is provided in the center of the annular base 32, penetrating the annular base 32 in the thickness direction. This opening 32c has a shape corresponding to a truncated cone whose diameter increases from the other end face (upper face) 32a toward one end face (lower face) 32b, for example.

[0038] Furthermore, a plurality of water supply passages 32e are formed in the annular base 32 so as to penetrate the annular base 32 so as to open at one end face (lower face 32b) and the other end face (upper face 32a). These water supply passages 32e are provided at approximately equal angular intervals along the circumferential direction of the annular base 32.

[0039] Furthermore, an annular groove 32d is formed concentrically with the opening 32c along the outer periphery of the annular base 32 on one lower surface 32b of the annular base 32. A plurality of grinding stones 34 according to this embodiment are fixed in the annular groove 32d so as to be arranged in a ring shape. Specifically, the base end of each grinding stone 34 is fixed in the annular groove 32d, and the other portion is exposed from the annular groove 32d.

[0040] In addition, each grinding wheel 34 has a rectangular parallelepiped shape extending parallel to a line tangent to the annular groove 32d in a plan view, or a shape obtained by slightly curving this rectangular parallelepiped so as to fit along the annular groove 32d. However, the shape of the grinding wheel 34 is not limited to this.

[0041] 3 is a partially enlarged cross-sectional view schematically showing the structure of a grinding wheel 34 according to this embodiment. The grinding wheel 34 includes abrasive grains 38 and a binder 36 that fixes the abrasive grains 38. The binder 36 may also include other components (for example, a filler).

[0042] The binder 36 is, for example, a vitrified bond whose main component is glass such as silicon dioxide (SiO2), a metal bond whose main component is metal such as copper (Cu), or a resin bond whose main component is resin such as phenolic resin. The abrasive grains 38 are particles made of, for example, diamond or cBN (cubic boron nitride).

[0043] Furthermore, the grinding wheel 34 according to this embodiment includes surfactant supply particles 40 contained in the binder 36. The surfactant supply particles 40 are particles that dissolve a surfactant into water when they come into contact with water. Typically, the surfactant supply particles 40 are granular surfactants having a predetermined average particle size, or powdered surfactants. Alternatively, the surfactant supply particles 40 may be composed of a water-soluble base material (organic or inorganic) and a surfactant mixed into this base material.

[0044] However, the form of the surfactant supply particle 40 is not limited to these. The surfactant supply particle 40 may be composed of a resin capsule that dissolves easily in water and a liquid covered by the resin capsule, and the liquid may contain a surfactant. In either case, when the surfactant supply particle 40 is exposed to the surface of the binder 36 (the surface of the grinding wheel 34) and comes into contact with water, the surfactant is eluted from the surfactant supply particle 40 into the water.

[0045] Here, the surfactant supply particles 40 contain, as a surfactant, for example, anionic surfactant particles, cationic surfactant particles, or nonionic surfactant particles. Examples of anionic surfactants include alkylbenzene sulfonic acid and its salts, alkyl sulfate ester salts, methyl taurate salts, and ether sulfonates. Examples of cationic surfactants include quaternary ammonium salts and amine salts. Examples of nonionic surfactants include nonylphenol-based, higher alcohol-based, polyhydric alcohol-based, polyoxyalkylene glycol-based, polyoxyethylene alkyl ester-based, polyoxyethylene alkyl ether-based, polyoxyethylene alkylphenol ether-based, and polyoxyethylene sorbitan alkyl ester-based surfactants. However, the surfactant contained in the surfactant supply particles 40 is not limited to these.

[0046] FIG. 4 is a side view that schematically shows how the workpiece 1 is ground in the grinding device 2 configured as described above. When the workpiece 1 is ground in the grinding device 2, the workpiece 1, which has the protective member 3 attached to its front surface 1a, is placed on the holding surface 6c of the holding table 6 via the protective member 3 (see FIG. 1), and the workpiece 1 is held by suction on the holding table 6, with the back surface 1b of the workpiece 1, which will be the surface to be processed, exposed upward. Note that the protective member 3 is omitted in FIG. 4. Then, the Y-axis movement mechanism is operated to move the holding table 6 below the grinding unit 8.

[0047] Thereafter, the spindle 26 is rotated around the wheel rotation axis 26a to rotate the grinding wheel 30, and the grinding stone 34 is moved along the circular orbit. Also, the holding table 6 is rotated around the table rotation axis 6d. Then, the lifting unit (Z-axis movement mechanism) 10 is operated to start lowering the grinding unit 8. Thereafter, when the lower surface of the grinding stone 34 moving on the circular orbit comes into contact with the back surface 1b of the workpiece 1, grinding of the workpiece 1 begins.

[0048] The grinding device 2 is equipped with a height gauge (not shown) that can measure the thickness of the workpiece 1, and continues to lower the grinding unit 8 while monitoring the thickness of the workpiece 1 with the height gauge. Thereafter, when the thickness of the workpiece 1 reaches a predetermined finishing thickness, the lowering of the grinding unit 8 is stopped and the grinding unit 8 is raised. This results in the workpiece 1 being thinned to the finishing thickness.

[0049] Here, while the workpiece 1 is being ground, water is supplied to one end face (lower surface 32b) of the annular base 32 through each water supply passage 32e. Alternatively, as shown in Fig. 4, the grinding device 2 may be provided with a water supply nozzle 42 that supplies water 44 to the annular base 32 from inside the annular base 32 of the grinding wheel 30. In this case, while the workpiece 1 is being ground, water 44 is supplied from the water supply nozzle 42 to one end face (lower surface 32b) of the annular base 32.

[0050] In either case, the water 44 supplied to one end face (lower face 32b) of the annular base 32 comes into contact with the grinding wheel 34 according to this embodiment. When the water 44 comes into contact with the grinding wheel 34, the surfactant supply particles 40 exposed on the surface of the binder 36 are eluted into the water 44. In other words, the water 44 becomes processing water containing a surfactant.

[0051] This processing water acts on the contact point between the grindstone 34 and the workpiece 1, i.e., the processing point. As the grindstone 34 and the workpiece 1 come into contact and grinding of the workpiece 1 progresses, processing heat due to friction and processing chips due to wear are generated from the grindstone 34 and the workpiece 1. The processing water absorbs the processing heat and processing chips and removes them from the vicinity of the processing point. Here, because the processing water contains surfactants eluted from the grindstone 34, adhesion of the processing chips absorbed in the processing water to the workpiece 1 is suppressed.

[0052] In this way, when the grinding wheel 34 according to this embodiment is used, there is no need to prepare processing water mixed with a surfactant in advance in the grinding device (processing device) 2. In the grinding device 2, processing water mixed with a surfactant can be used by simply supplying pure water to the grinding wheel 34. Therefore, there is no need to incorporate into the grinding device 2 a device that adds a predetermined amount of chemical solution or the like to the water, and there is no need to take the trouble of periodically refilling the device with chemical solution.

[0053] When grinding the workpiece 1, the binder 36 of the grinding wheel 34 gradually wears away, and new surfactant supply particles 40 are successively exposed on the surface of the binder 36. Therefore, even when the grinding wheel 34 wears away, the supply source of the surfactant is not depleted. Furthermore, when the grinding wheel 30 is replaced after the grinding wheel 34 has worn down to a predetermined extent, the grinding wheel 34 is also replaced, so the supply source of the surfactant is not depleted.

[0054] In particular, when the surfactant supply particles 40 are uniformly dispersed throughout the binder 36, the surfactant supply particles 40 are always exposed to the surface of the binder 36 in the same manner regardless of the degree of wear of the grinding wheel 34, and the surfactant continues to dissolve into the water 44 from the grinding wheel 34 in approximately the same amount. Therefore, as long as the supply conditions of the water 44 are constant, the surfactant concentration in the processing water acting on the processing point remains stable. Therefore, with the grinding wheel 34 according to this embodiment, there is no need to bother with managing the surfactant concentration in the processing water.

[0055] The use and application of the grindstone according to this embodiment are not limited to the grindstone 34 included in the grinding wheel 30. The grindstone according to this embodiment may also be used in a cutting blade attached to a cutting device that cuts the workpiece 1. Next, a cutting device, which is another example of a processing device in which the grindstone according to this embodiment is used, will be described.

[0056] 5 is a cross-sectional view that schematically shows how a workpiece 1 is cut by a cutting device (processing device) 50. First, a description will be given of the cutting device 50. The cutting device 50 includes a holding table 52 that holds the workpiece 1, and a cutting unit 60 that cuts the workpiece 1 held by the holding table 52.

[0057] The holding table 52 is moved in the processing feed direction by a processing feed unit (not shown). The cutting unit 60 is moved in the indexing feed direction by an indexing feed unit (not shown). The cutting unit 60 is moved in the cutting feed direction by a cutting feed unit (not shown). Here, the indexing feed direction, processing feed direction, and cutting feed direction are perpendicular to one another. The holding table 52 is connected to a rotational drive source (not shown) such as a motor, and rotates around a rotation axis that is approximately parallel to the cutting feed direction.

[0058] 5 includes a cross-sectional view showing a schematic view of the holding table 52. The holding table 52 includes a disk-shaped frame 54 having a recess exposed upward, and a disk-shaped porous member 56 housed in the recess of the frame 54. The porous member 56 has a diameter equal to that of the workpiece 1. A suction path (not shown) connected to a suction source (not shown) such as an ejector is formed inside the holding table 52.

[0059] The holding table 52 also includes a plurality of clamps 58 that fix the annular frame 7 that is integrated with the workpiece 1 via adhesive tape (dicing film) 5. The clamps 58 clamp and fix the frame 7 that is integrated with the workpiece 1 placed on the holding table 52.

[0060] When the workpiece 1 is placed on the upper surface of the holding table 52, the frame 7 is clamped with the clamps 58, and the negative pressure generated by the suction source is applied to the workpiece 1 through the suction path and the porous member 56, the workpiece 1 can be suction-held by the holding table 52. The upper surface of the holding table 52 is formed approximately parallel to the horizontal plane and serves as the holding surface.

[0061] A cutting blade 88 having an annular grinding stone 90 according to this embodiment is rotatably mounted on the cutting unit 60. The cutting unit 60 cuts the workpiece 1 held by the holding table 52 by rotating the cutting blade 88 and bringing the grinding stone 90 into contact with the workpiece 1.

[0062] 6 is an exploded perspective view showing a schematic view of some of the components of the cutting unit 60. The cutting unit 60 includes a spindle housing 62 connected to an indexing feed unit of the cutting device 50, etc. A spindle 64 is rotatably supported in the spindle housing 62. The tip (front end) of the spindle 64 protrudes forward from the spindle housing 62.

[0063] A rear flange 68 is attached to the tip of the spindle 64. A threaded hole 66 is formed in the tip of the spindle 64, into which a bolt 76 is tightened. An insertion hole 74 extending from the rear to the front is formed in the rear flange 68. When the rear flange 68 is fixed to the spindle 64, the spindle 64 is inserted into this insertion hole 74 from the rear side of the rear flange 68. Then, when the bolt 76 is tightened into the threaded hole 66 at the tip of the spindle 64 via a washer 78, the rear flange 68 is fixed to the spindle 64.

[0064] The rear flange 68 includes a flange portion 70 extending radially outward, and a boss portion 72 protruding forward from the surface (front surface) of the flange portion 70. The outer peripheral surface of the flange portion 70 serves as an abutment surface 80 that abuts against the rear side surface of the cutting blade 88. This abutment surface 80 is formed in an annular shape when viewed from the axial direction of the spindle 64. The boss portion 72 is formed in a cylindrical shape, and a screw thread 82 is provided on its outer peripheral surface.

[0065] As described below, a circular through hole 90a is formed in the center of the cutting blade 88, through which the boss portion 72 is inserted, and the cutting blade 88 is attached to the rear flange 68 by inserting the boss portion 72 into this through hole 90a.

[0066] The front flange 84 has a flange portion extending radially outward, and the back surface of the outer circumferential side of this flange portion serves as an abutment surface that abuts against the side surface on the front side of the cutting blade 88. This abutment surface is formed in an annular shape when viewed from the axial direction of the spindle 64. The front flange 84 has an opening 84a that is inserted into the boss portion 72 of the rear flange 68.

[0067] A screw groove 86a corresponding to the thread 82 of the boss portion 72 is formed on the inner surface of the fixing nut 86 that fixes the front flange 84. The front flange 84 is attached to the rear flange 68 so that the boss portion 72 passes through the opening 84a, the cutting blade 88 is sandwiched between the front flange 84 and the rear flange 68, and the fixing nut 86 is tightened onto the boss portion 72. In this manner, the cutting blade 88 is attached to the cutting unit 60.

[0068] Here, the cutting blade 88 will be described. Fig. 6 includes a perspective view that schematically shows the cutting blade 88. The cutting blade 88 shown in Fig. 6 is, for example, a cutting blade called a washer type, which is made up of an annular grinding stone 90. However, the cutting blade 88 attached to the cutting unit 60 is not limited to the washer type. The cutting blade 88 may also be a hub blade having an annular base to which the annular grinding stone 90 is fixed on the outer periphery.

[0069] The grinding stone 90 of the cutting blade 88 has the same configuration as the grinding stone 34 of the grinding wheel 30 described above. That is, the grinding stone 90 includes abrasive grains 38 and a binder 36 that secures the abrasive grains 38. Furthermore, the grinding stone 90 includes surfactant supply particles 40 contained in the binder 36. When the cutting blade 88 is attached to the cutting unit 60 and rotated around an axis along the penetrating direction of the through-hole 90a and brought into contact with the workpiece 1, the workpiece 1 is cut.

[0070] 5, the cutting unit 60 includes a pair of generally L-shaped nozzles 92 that sandwich the lower part of the cutting blade 88 from the front and rear. The nozzles 92 are connected to the distal end of a liquid supply pipe (not shown), and the proximal end of this liquid supply pipe is connected to a pipe that leads to a water supply source. The cutting unit 60 may further include a jet nozzle (not shown).

[0071] When the workpiece 1 is cut by the cutting blade 88, cutting chips are generated and scattered on the workpiece 1. In addition, processing heat is generated due to friction between the cutting blade 88 and the workpiece 1. Therefore, when cutting the workpiece 1 with the cutting blade 88, water is supplied from the nozzle 92 to the workpiece 1 and the grindstone 90, and the processing chips and processing heat are absorbed into the water and removed.

[0072] When cutting the workpiece 1 using the cutting blade 88 equipped with the grinding stone 90, first, the rotation of the spindle 64 is started to rotate the cutting blade 88. At the same time, the supply of water to the workpiece 1 and the grinding stone 90 is started. Then, while the rotation of the grinding stone 90 and the supply of water are continued, the grinding stone 90 is caused to cut into the workpiece 1. In this way, the workpiece 1 is cut.

[0073] When water is supplied to the grindstone 90, the surfactant is eluted into the water from the surfactant supply particles 40 exposed from the binder 36. That is, this water becomes processing water containing a surfactant. This processing water then captures the processing debris and the like generated when the workpiece 1 is cut by the grindstone 90 according to this embodiment. Here, because the processing water contains the surfactant eluted from the grindstone 90, adhesion of the processing debris captured in the processing water to the workpiece 1 is suppressed. In this way, even when the grindstone 90 is used in the cutting device 50, processing water containing a surfactant can be used without providing the cutting device 50 with a device for mixing the surfactant into the water.

[0074] Next, a method for manufacturing the grindstones 34, 90 according to this embodiment will be described. The grindstones 34, 90 can be manufactured, for example, by mixing various powdered materials to form a mixed material, molding the mixed material into a predetermined shape, and firing the mixed material. Figure 9 is a flowchart showing the flow of each step in the method for manufacturing the grindstones 34, 90. Each step will be described in detail below.

[0075] First, a mixing step S10 is performed. FIG. 7 is a cross-sectional view showing a schematic diagram of the mixing step S10. In the mixing step S10, a component 36a, which is the material for the binder 36, abrasive grains 38, and surfactant supply particles 40 are mixed together to form a mixed material 100. The component 36a is, for example, granular, powdery, or liquid, and becomes the fired binder 36 when heated to a predetermined temperature.

[0076] In the mixing step S10, for example, an agitator 94 shown in Fig. 7 is used. The agitator 94 includes, for example, a cylindrical housing 96 and a rotary drive source (not shown) that rotates the housing 96 about an axis 98a that passes through the center of a bottom surface 96a of the housing 96 in a direction perpendicular to the bottom surface 96a. The tip of the axis 98 is connected to the bottom surface 96a side of the housing 96, and the rotary drive source is connected to the other end of the axis 98. The housing 96 has a material inlet 96b on the side facing the bottom surface 96a, and when the material is to be agitated by the agitator 94, the material is introduced into the housing 96 through the inlet 96b.

[0077] In the mixing step S10, predetermined amounts of components 36a, which are the materials for the binder 36, abrasive grains 38, and surfactant supply particles 40, are weighed and fed into the housing 96 of the mixer 94 through an inlet 96b. For example, in the mixed material 100, the content of surfactant supply particles 40 relative to the total amount of the binder 36 (components 36a) and surfactant supply particles 40 is preferably 1 to 10 vol%.

[0078] Thereafter, when the rotary drive source is operated to rotate the housing 96, the member 36a, the abrasive grains 38, and the surfactant supply particles 40 are uniformly mixed to form the mixed material 100. Note that fillers and the like may be mixed into the mixed material 100 to adjust the performance of the grinding wheels 34, 90 to be manufactured.

[0079] After the mixing step S10, a molding step S20 is carried out in which the mixed material 100 is molded to obtain a molded body. Fig. 8(A) is a cross-sectional view showing the molding step. For example, the molding step is carried out using a pressure molding device 102.

[0080] The pressure molding device 102 includes a mold 104 that accommodates the mixed material 100, and a pressing tool (pressing member) 106 that presses the mixed material 100 accommodated in the mold 104. The upper surface of the mold 104 is provided with a recess 104a having a shape corresponding to the shape of the grinding wheels 34, 90.

[0081] For example, when forming a grinding stone 34 having a substantially rectangular parallelepiped shape, a mold 104 is used that has a recess 104a formed in a substantially rectangular parallelepiped shape to match the dimensions of the grinding stone 34. When forming an annular grinding stone 90, a mold 104 is used that has a recess 104a formed in an annular shape to match the dimensions of the grinding stone 90.

[0082] The pressing tool 106 includes a plate-shaped pressing portion 106a that is inserted into the recess 104a of the mold 104, and a columnar shaft portion 106b that is connected to the upper surface side of the pressing portion 106a. When the shaft portion 106b is lowered, the pressing portion 106a is pressed toward the bottom of the recess 104a of the mold 104.

[0083] In the molding step S20, first, the mixed material 100 is poured into the recess 104a of the mold 104. Then, the pressing tool 106 is lowered to press the mixed material 100 toward the bottom of the recess 104a with the lower surface of the pressing part 106a. This causes the mixed material 100 to be compression molded. As a result, a molded body having a shape that reflects the shape of the recess 104a is formed.

[0084] Next, a firing step S30 is carried out to fire the molded mixed material 100. Fig. 8(B) is a cross-sectional view showing the firing step S30. The firing step is carried out using a firing furnace 110, for example.

[0085] In the firing step S30, first, the green body 108 formed by molding the mixed material 100 is placed in a container 112. The container 112 is made of a heat-resistant metal or ceramic, and has a main body 114 and a lid 116. The top surface of the main body 114 is provided with a recess 114a capable of accommodating the formed green body 108 (mixed material 100). When the green body 108 is placed in the recess 114a of the main body 114 and the top of the recess 114a is closed with the lid 116, the recess 114a is sealed with the green body 108 placed therein.

[0086] Thereafter, the container 112 containing the compact 108 is sealed in a firing furnace 110 and heated, and the compact 108 is fired at a low temperature of 180°C or less. This firing fires the compact 108, forming the grinding wheels 34, 90. Note that the firing of the mixed material 100 may also be performed after the mixed material 100 has been formed by placing the mold 104 and the pressing part 106a of the pressing tool 106 (see FIG. 8(A)) in the firing furnace 110 and heating them.

[0087] In addition, if the content of surfactant supply particles 40 relative to the total amount of the binder 36 (component 36a) and surfactant supply particles 40 in the mixed material 100 is 1 to 10 vol%, the content of surfactant supply particles 40 in the grinding wheels 34, 90 thus formed will also be approximately the same. In other words, the content of surfactant supply particles 40 in the parts of the grinding wheels 34, 90 excluding the abrasive grains 38 will be approximately 1 to 10 vol%.

[0088] As described above, the grinding wheels 34, 90 according to this embodiment contain surfactant supply particles 40 in the binder 36. When water comes into contact with the surfactant supply particles 40, the surfactant dissolves in the water. Therefore, when the grinding wheels 34, 90 are used to process the workpiece 1 while supplying water to the workpiece 1, the surfactant dissolves in the processing water. The processing water containing the surfactant prevents chips generated during processing from adhering to the workpiece 1. The grinding wheels 34, 90 can be used in processing equipment in the same way as conventional grinding wheels, without the need for any special device to be incorporated into the processing equipment.

[0089] In the above embodiment, a case has been described in which, when water such as pure water is supplied to the grindstones 34, 90 used to process the workpiece 1, the surfactant dissolves in the water from the surfactant supply particles 40, thereby obtaining processing water containing the surfactant. However, one aspect of the present invention is not limited to this.

[0090] For example, in a processing device using the grindstones 34, 90, processing water that has a surfactant already mixed in may be used, and this processing water may be supplied to the grindstones 34, 90. Even in this case, if the amount of surfactant already mixed in the processing water is insufficient, the surfactant will dissolve from the surfactant supply particles 40 into the processing water supplied to the grindstones 34, 90, increasing the surfactant concentration in the processing water. This makes it difficult for processing debris taken in the processing water to adhere to the workpiece 1.

[0091] In addition, the structures and methods according to the above-described embodiments can be modified as appropriate without departing from the scope of the present invention. [Explanation of symbols]

[0092] 1 Workpiece 1a surface 1b back side 3 Protective materials 5 adhesive tape 7 frames 2 Grinding equipment 4 Foundation 4a Recess 4b Dustproof / waterproof cover 6 Holding table 6a Frame 6b Support 6c Holding surface 6d Table rotation axis 8 Grinding Unit 10 Lifting unit 12 Support part 14 Guide rail 16 Moving Plate 18 Ball screw 20 Pulse motor 22 Retaining member 24 Spindle housing 26 Spindle 26a Wheel rotation axis 28 Wheel mount 30 Grinding Wheel 32 Circular Base 32a top surface 32b Bottom side 32c aperture 32d Annular groove 32e Water supply channel 34 Whetstone 36 Binding material 36a Component 38 abrasive grains 40 Surfactant supply particles 42 Water supply nozzle 44 water 50 Cutting equipment 52 Holding table 54 Frame 56 Porous materials 58 Clamp 60 Cutting Unit 62 Spindle housing 64 spindles 66 screw holes 68 Rear flange 70 Flange 72 Boss section 74 Insertion hole 76 volts 78 Washer 80 Contact surface 82 threads 84 Front flange 84a aperture 86 Fixing nut 86a screw groove 88 Cutting Blade 90 Whetstone 90a through hole 92 nozzles 94 Stirrer 96 cabinet 96a bottom 96b Inlet 98 Shaft 98a axis 100 mixed materials 102 Pressure molding equipment 104 Mold 104a Recess 106 Pressing tool 106a Pressing part 106b Shaft 108 Molded body 110 Kiln 112 Container 114 Main body 114a Recess 116 Lid

Claims

1. A grindstone, The abrasive grinding tool comprises abrasive grains, a binder for fixing the abrasive grains, and surfactant supply particles contained in the binder, When water comes into contact with the surfactant supply particles, the surfactant is eluted from the surfactant supply particles into the water.

2. 2. The grindstone according to claim 1, wherein the surfactant supply particles contain any one of anionic surfactant particles, cationic surfactant particles, and nonionic surfactant particles as the surfactant.

3. 2. The grinding wheel according to claim 1, wherein the binder is mainly composed of a resin.

4. an annular base having a recessed annular groove formed on one end surface; A grinding wheel, characterized in that the grinding stone according to any one of claims 1 to 3 is arranged in the annular groove and fixed to the annular base.

5. 4. The grinding wheel according to claim 1, wherein the entire grinding wheel is annular.

6. A method for manufacturing a grinding wheel, comprising: a mixing step of mixing the abrasive grains, the bond material, and the surfactant feed particles to form a mixed material; a molding step of molding the mixed material to obtain a molded body; and a firing step of firing the compact to obtain a grinding wheel, A method for manufacturing a grindstone, characterized in that when water comes into contact with the surfactant supply particles contained in the grindstone, the surfactant is eluted from the surfactant supply particles into the water.

7. 7. The method for manufacturing a grindstone according to claim 6, wherein the content of the surfactant supply particles in the mixed material is 1 to 10 vol % relative to the total amount of the binder and the surfactant supply particles.

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