Metal blade and method for manufacturing the same

Abstract

To provide a metal blade capable of high-quality processing.SOLUTION: An annular thin plate-shaped metal blade according to an embodiment of the present invention includes a metal bond phase and abrasive grains, and the area ratio of the abrasive grains exposed from the surface to the area of the surface arranged at both ends in the direction along the central axis of the metal blade is 10% or less.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a metal blade and a method for manufacturing the metal blade. [Background technology]

[0002] Metal blades are used to cut substrates such as semiconductor materials into individual chips. Metal blades are generally circular and comprise abrasive grains and a metal bond phase that holds the abrasive grains, with the abrasive grains dispersed in the metal bond phase.

[0003] The metal blade rotates around the axis of rotation, and its outer periphery comes into contact with the workpiece, cutting it. When cutting a workpiece with a metal blade, the blade maintains its sharpness through self-sharpening. This is the process by which abrasive grains held in the metal bond phase fall off the metal blade due to cutting load or wear, exposing new abrasive grains to the surface.

[0004] As an example of a metal blade that maintains its sharpness through self-sharpening, Patent Document 1 discloses a metal blade that includes a disk-shaped metal bond phase, a cutting edge formed on the outer peripheral edge of the metal bond phase, a plurality of abrasive grains dispersed in the metal bond phase, and a plurality of pores that extend inside the metal bond phase and open to the outer surface of the metal bond phase. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-104079 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, when the inventors investigated the workability of workpieces using metal blades, they found that the longer the cutting distance of the workpiece, the shorter the cutting width by the metal blade, resulting in a skirt-shaped cut surface and a decrease in processing quality.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a metal blade that is capable of high-quality cutting. [Means for solving the problem]

[0008] The inventors discovered that this was caused by a reduction in the width of the metal blade's outer periphery. This reduction in width was due to increased friction caused by the abrasive grains falling off the metal blade as the metal blade cut into the workpiece. The inventors then came up with the idea of suppressing the reduction in width by reducing the abrasive grains protruding from the side.

[0009] The present invention was made based on these findings, and the gist of the present invention is as follows. [1] A metal blade according to one embodiment of the present invention is a thin, annular metal blade comprising a metal bond phase and abrasive grains, and the area ratio of the abrasive grains exposed from the surface to the area of the surface arranged at both ends in a direction along the central axis of the metal blade is 10% or less. [2] In the metal blade described in [1] above, it is preferable that the maximum protruding height of the abrasive grains protruding from the surface in the direction along the central axis O is not more than half the average grain size of the abrasive grains. [3] In the metal blade described in [1] or [2] above, it is preferable that the area ratio of the abrasive grains exposed from the surface to the area of the surface arranged at both ends along the central axis of the metal blade is 0%. [4] Another aspect of the present invention relates to a method for manufacturing a metal blade, which is a method for manufacturing a metal blade having a circular thin plate shape comprising a metal bond phase and abrasive grains, and which comprises a molding step of molding a laminate containing metal powder and the abrasive grains, the laminate having a different content of the abrasive grains in the central axis direction of the metal blade, and a sintering step of sintering the metal powder. [5] In the method for manufacturing a metal blade described in [4] above, the molding step may be a coating film formation step of forming a first coating layer from a first slurry containing at least a first metal powder, forming a second coating layer on the surface of the first coating layer from a second slurry containing a second metal powder and the abrasive grains, and forming a third coating layer on the surface of the second coating layer from a third slurry containing at least a third metal powder, thereby obtaining a layered coating film, and the sintering step may be a degreasing and sintering step of firing the coating film obtained in the coating film formation step. [6] In the method for manufacturing a metal blade described in [4] above, the molding step may be a laminate formation step of forming a laminate consisting of a first powder layer containing at least a first metal powder, a second powder layer containing a second metal powder and the abrasive grains and arranged on one surface of the first powder layer, and a third powder layer containing at least a third metal powder and arranged on the surface of the second powder layer, and the sintering step may be a step of sintering the laminate to form a sintered body. [7] In the method for manufacturing a metal blade according to any one of the above items [4] to [6], it is preferable that the composition of the metal powder is the same along the central axis of the metal blade. [Effects of the Invention]

[0010] The metal blade according to the above aspect enables high-quality cutting. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a side view showing a metal blade according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing the AA section of FIG. [Figure 3]FIG. 3 is an enlarged schematic view of part B in FIG. 2. [Figure 4] 10 is a graph showing the evaluation results of the blade width reduction amount after cutting 1000 m of the workpiece in the examples. [Figure 5] 1 is a graph showing the evaluation results of the cutting distance and the amount of wear of the workpiece in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0012] <Metal Blade 1> A metal blade 1 according to one embodiment of the present invention will be described below with reference to Figures 1 to 3. Figure 1 is a side view showing a metal blade 1 according to one embodiment of the present invention. Figure 2 is a cross-sectional view showing a cross section taken along line AA in Figure 1. Figure 3 is a schematic view showing an enlarged view of part B in Figure 2. Note that the dimensions and ratios of each component in the figures do not represent the actual dimensions and ratios of each component.

[0013] (Outline of Metal Blade 1) First, a schematic configuration of a metal blade 1 according to this embodiment will be described. The metal blade 1 according to this embodiment is in the form of a thin circular plate, as shown in Fig. 1. In detail, the metal blade 1 has an outer surface 11 and an inner surface 12 that are concentrically arranged around a central axis O, and a through hole 13 is formed inside the inner surface 12, penetrating in a direction along the central axis O. In this specification, the direction along the central axis O of the metal blade 1 is referred to as the width direction.

[0014] The thickness (length in the width direction) of the metal blade 1 is not particularly limited and can be, for example, 0.05 mm or more and 0.40 mm or less. The thickness of the metal blade 1 may be 0.08 mm or more, 0.10 mm or more, 0.15 mm or more, or 0.25 mm or more. The thickness of the metal blade 1 may also be 0.25 mm or less, 0.15 mm or less, 0.10 mm or less, or 0.08 mm or less.

[0015] The outer diameter of the metal blade 1 is not particularly limited and can be, for example, 50 mm or more and 100 mm or less. The outer diameter of the metal blade 1 may be 62 mm or more, or 80 mm or more. The outer diameter of the metal blade 1 may be 80 mm or less, or 62 mm or less.

[0016] The inner diameter of the metal blade 1 is not particularly limited and can be, for example, 40 mm or more and 88.9 mm or less. The inner diameter of the metal blade 1 may be 60 mm or more, or 80 mm or more. The inner diameter of the metal blade 1 may be 80 mm or less, or 60 mm or less.

[0017] 3, the metal blade 1 includes a metal bond phase 101 and abrasive grains 102 dispersed in the metal bond phase 101. In the metal blade 1 according to this embodiment, the area ratio of the abrasive grains 102 exposed from the side surfaces 10A and 10B to the area of the surfaces (side surfaces 10A and 10B) arranged at both ends in the direction along the central axis O is 10% or less. This will be explained in detail below.

[0018] (Metal bond phase 101) The metal bond phase 101 is a sintered body of powder containing a metal element as a main component. The metal element constituting the metal bond phase 101 is, for example, one or more selected from the group consisting of Cu, Sn, Co, Ni, Fe, and Cu alloys. The metal bond phase 101 has, for example, a Cu-Sn alloy as a base material. The metal bond phase 101 may contain other elements.

[0019] (Abrasive 102) The abrasive grains 102 are made of a material harder than the metal bond phase 101. The abrasive grains 102 may be, for example, natural diamond particles, synthetic diamond particles, or cubic boron nitride (cBN) particles, or a mixture of these particles.

[0020] The average particle size of the abrasive grains 102 is appropriately selected depending on the thickness of the metal blade 1. The average particle size of the abrasive grains 102 is preferably, for example, ¼ or less of the thickness of the metal blade 1. The average particle size of the abrasive grains 102 may be ⅕ or less of the thickness of the metal blade 1. The average particle size of the abrasive grains 102 may be, for example, 0.13 mm or less, 0.08 mm or less, or 0.045 mm or less. There is no particular lower limit to the average particle size of the abrasive grains 102, and it may be, for example, 0.003 mm or more.

[0021] The average particle size of the abrasive grains 102 refers to the particle size measured and calculated by the following method: that is, the 50% particle size (median size) measured by a wet particle size distribution analyzer (reflection type, transmission type) or a dry particle size distribution analyzer. The volume average particle size is measured using a laser diffraction / scattering measurement device. Specifically, a Microtrac laser diffraction / scattering measurement device MT3300EXII-SDC is used. The sample is placed in water (25°C, pH 7), the transmittance of the measurement sample is set to transparent, the particle refractive index is 1.81, and the shape is aspherical. The average particle size is measured using a volume-based particle size distribution. The solvent refractive index is set to 1.333, the measurement time is 30 seconds, and the average of two measurements is taken as the measured value.

[0022] The particles of each material that make up the abrasive grains 102 can be commercially available and are particles that essentially contain the respective components, but may also contain other components as impurities.

[0023] (filler) The metal blade 1 according to this embodiment may contain a filler in addition to the metal bond phase 101 and the abrasive grains 102. The filler is an inorganic filler having a lower hardness than the abrasive grains 102, such as hexagonal boron nitride (hBN) particles, silicon nitride (SiC) particles, glass beads (SiO), sulfides, precious metal particles, or a mixture of these particles.

[0024] The average particle size of the filler may be, for example, 3 μm or more and 45 μm or less. The average particle size of the filler may be calculated in the same manner as that of the abrasive grains 102.

[0025] (Side 10A, 10B) [Area ratio of abrasive grains 102 exposed from side surfaces 10A and 10B] In the metal blade 1 according to this embodiment, the area ratio of the abrasive grains 102 exposed from the side surfaces 10A and 10B to the area of each of the side surfaces 10A and 10B is 10% or less. When the area ratio of the abrasive grains exposed from the side surfaces 10A and 10B to the area of each of the side surfaces 10A and 10B is 10% or less, friction caused by the abrasive grains 102 protruding from the side surfaces 10A and 10B contacting the workpiece is reduced, and the abrasive grains 102 are prevented from falling off. This prevents the blade width from becoming thinner, resulting in high machining quality. From the viewpoint of reducing friction, the area ratio of the abrasive grains exposed from the side surfaces 10A and 10B to the area of each of the side surfaces 10A and 10B is preferably 5% or less, and may be 10% or less. There is no particular lower limit to the area ratio of the abrasive grains exposed from the side surfaces 10A and 10B to the area of each of the side surfaces 10A and 10B, and the area ratio may be 0% or more or 5% or more.

[0026] The area ratio of the abrasive grains exposed from the side surfaces 10A and 10B relative to the area of each of the side surfaces 10A and 10B is measured using the following method. Specifically, the side surface 10A or 10B is observed at 500x magnification using a digital microscope (Keyence Corporation: VHX-6000), and the abrasive grains 102 are selected based on the observed image. Specifically, the area with a metallic luster is determined to be the metal bond phase 101. The area without a metallic luster is determined to be the area where the abrasive grains 102 are exposed. In this case, the area of each abrasive grain 102 is calculated by regarding those with the same color as the abrasive grains 102. Then, the area ratio of the abrasive grains 102 relative to the area of the side surface 10A or 10B in that field of view is calculated. In order to cover the entire area of the side surface 10A or 10B, multiple images are acquired, and the area ratio is calculated for each image using the above method. The average area ratio is calculated using the area ratio for each field of view. This calculated average area ratio is defined as the area ratio of exposed abrasive grains 102. If the metal blade 1 contains a non-metallic filler, the exposed filler will not have a metallic luster. In this case, the area without a metallic luster is divided proportionally according to the ratio of the amount (volume %) of the abrasive grains 102 to the amount (volume %) of the filler, and the area ratio of the abrasive grains 102 is calculated.

[0027] In the metal blade 1 according to this embodiment, the maximum protruding height of the abrasive grains 102 protruding from the surface in the direction along the central axis O relative to the area of the side surfaces 10A and 10B is preferably 1 / 2 or less of the average grain size of the abrasive grains 102. The maximum protruding height of the abrasive grains 102 is more preferably 1 / 3 or less of the average grain size of the abrasive grains 102. If the protruding height of the abrasive grains 102 protruding from the side surfaces 10A and 10B is large, the abrasive grains are likely to fall off due to friction with the workpiece. If the protruding height of the abrasive grains 102 is small, friction caused by contact with the workpiece is further reduced, and the abrasive grains 102 are further prevented from falling off. This further suppresses blade width thinning, resulting in even higher machining quality. Therefore, it is preferable that the protruding height of the protruding abrasive grains 102 is small. Therefore, in the metal blade 1 according to this embodiment, it is preferable that the maximum protruding height of the abrasive grains 102 protruding from the surface in the direction along the central axis O relative to the area of the side surfaces 10A and 10B is 1 / 2 or less of the average particle size of the abrasive grains 102.

[0028] The protruding height of the abrasive grains 102 protruding from each side surface 10A, 10B is measured using the following method. That is, the abrasive grains 102 are identified using the above method in an image of the side surface 10A observed with a digital microscope (Keyence Corporation: VHX-6000), the image is converted into 3D, the area including the abrasive grains 102 is designated with a straight line, and line roughness measurement is performed. The maximum height obtained by multiple line roughness measurements in the above field of view is taken as the maximum protruding height.

[0029] So far, the metal blade 1 according to this embodiment has been described in detail. In the metal blade 1 according to this embodiment, the outer surface 11 functions as a cutting edge. More specifically, a spindle of a processing device is inserted into the through-hole 13 via a flange (not shown), and the metal blade 1 is fixed to the spindle. The spindle rotates around the central axis O, and the outer surface 11 of the rotating metal blade 1 comes into contact with the workpiece, thereby cutting the workpiece. In this case, in the metal blade 1 according to this embodiment, the area ratio of the abrasive grains 102 protruding from the side surfaces 10A and 10B that contact the workpiece is small, so that the abrasive grains 102 protruding from the side surfaces 10A and 10B are prevented from falling off due to friction. This prevents the blade width from becoming thinner, and as a result, prevents deterioration in processing quality.

[0030] The metal blade 1 according to this embodiment is suitable for precisely cutting workpieces such as electronic component materials containing hard and brittle materials such as glass, quartz, ceramics, etc. The workpieces are not limited to electronic component materials containing the above-mentioned highly brittle materials, and may be materials other than those mentioned above.

[0031] <Metal Blade 1 Manufacturing Method> Next, a method for manufacturing the metal blade 1 according to this embodiment will be described. The method for manufacturing the metal blade 1 according to this embodiment includes a molding step of molding a laminate containing metal powder and abrasive grains 102, and a sintering step of sintering the metal powder. Below, as a first manufacturing method, a method for manufacturing the metal blade 1 using a slurry containing at least metal powder that becomes the metal bond phase 101 and a slurry containing the metal powder and abrasive grains will be described. As a second manufacturing method, a method for manufacturing the metal blade 1 using a mixed powder obtained by mixing the metal powder and abrasive grains will be described.

[0032] (First manufacturing method) In the first manufacturing method, the molding step is a coating film forming step in which a first coating layer is formed from a first slurry containing at least a first metal powder, a second coating layer is formed on the surface of the first coating layer from a second slurry containing a second metal powder and the abrasive grains, and a third coating layer is formed on the surface of the second coating layer from the first slurry containing at least the first metal powder to obtain a layered coating, and the sintering step is a degreasing and sintering step in which the coating obtained in the coating film forming step is degreased and sintered. In the first manufacturing method, after the sintering step, inner and outer diameter processing, grinding and lapping are performed as necessary.

[0033] [Coating film formation process] In the coating film forming process, a first sheet is formed from a first slurry containing metal powder, and a second sheet is similarly formed from a second slurry containing metal powder and abrasive grains 102. After the first and second sheets are dried, they are cut into a ring shape with a predetermined diameter, and the ring-shaped second sheet is sandwiched between the ring-shaped first sheets on both sides to obtain a layered coating film.

[0034] The first slurry is composed of a first metal powder that will become the metal bond phase 101 and a dispersion medium. The dispersion medium may be a cellulose-based thickener as a base, to which a surfactant, a glycol-based solvent, or the like is added to adjust the viscosity and dispersion state. The viscosity of the dispersion medium is preferably adjusted to a range of 0.86 to 1.43 Pa·s.

[0035] The first metal powder is, for example, one or more powders selected from the group consisting of Cu, Sn, Co, Ni, Fe, and Cu alloys.

[0036] The average particle size of the first metal powder contained in the first slurry is not particularly limited, but is preferably around 5 μm from the viewpoint of uniform dispersion of the material. However, the average particle size of the metal powder contained in the first slurry may be 5 μm or more.

[0037] The concentration of the metal powder in the first slurry is not particularly limited relative to the total weight of the first slurry, but is preferably adjusted to 60% by weight or more and 70% by weight or less from the viewpoint of formability of the first sheet. Depending on the state of sheet formation, the concentration of the metal powder in the first slurry may be adjusted to 60% by weight or less or 70% by weight or more.

[0038] The second slurry is composed of a second metal powder that becomes a metal bond phase 101, abrasive grains 102, and a dispersion medium. The dispersion medium may be the same as that of the first slurry. The average particle size of the second metal powder contained in the second slurry is in the same range as the average particle size of the first metal powder contained in the first slurry. The first metal powder in the first slurry and the second metal powder in the second slurry may have the same composition or different compositions.

[0039] The concentration of the second metal powder in the second slurry is preferably adjusted to 60% by weight or more and 70% by weight or less based on the total weight of the second slurry, and may be adjusted to 60% by weight or less or 70% by weight or more depending on the state of sheet molding.

[0040] Furthermore, the first slurry and the second slurry may contain a filler as needed.

[0041] The first and second slurries can be produced using a known dispersing device, such as a rotary stirrer, an Eirich stirrer, or a Henschel stirrer.

[0042] The first sheet and the second sheet can be formed by a known coating film forming method, for example, a doctor blade method, a slurry casting method, an applicator method, a roll coater method, or the like.

[0043] A layered coating film is obtained by sandwiching a second sheet cut to the desired size from the second sheet with two first sheets cut to the same desired size on both sides. Thus, the first sheet placed on one side of the second sheet becomes the first coating film layer, the second sheet becomes the second coating film layer, and the first sheet placed on the opposite side of the second sheet from the first sheet becomes the third coating film layer.

[0044] [Debinding and sintering process] In the degreasing and sintering process, the layered coating is heat treated to remove the dispersion medium (degreasing process), and then in the sintering process, the metal powder is sintered to obtain a sintered body.

[0045] (Degreasing process) The degreasing atmosphere is a hydrogen atmosphere. The degreasing temperature is 400° C. or higher and 450° C. or lower, and is preferably 430° C. or higher. The degreasing time is 3 hours or longer.

[0046] (Sintering process) The sintering atmosphere is an inert gas atmosphere, such as a nitrogen atmosphere or an argon atmosphere. The sintering temperature can be, for example, 600°C to 850°C. The sintering temperature may be changed depending on the sintering condition, taking into account the melting point of the metal powder used. The sintering time is the holding time at the set temperature, and can be, for example, 10 minutes to 30 minutes. From the viewpoint of dimensional and physical property stability, the sintering time is preferably 10 minutes or more. In this process, pressure is applied to the coating film after the degreasing process in the width direction. The magnitude of the pressure is not particularly limited and can be, for example, 20 MPa to 40 MPa. The sintering process is carried out in a sintering furnace. The metal powder is sintered by the sintering process to form a metal bond phase 101. Each metal powder shrinks due to heating and compression during the sintering process. As a result, the abrasive grains 102 in the center bite into the metal bond phases 101 located on the side surfaces, preventing the metal bond phases 101 from falling off.

[0047] [Grinding and lapping process] In the grinding and lapping process, the outer and inner diameters of the sintered body are ground to predetermined dimensions, and the sintered body is then lapped to a predetermined thickness to obtain a metal blade 1. The outer diameter can be adjusted using a known grinding device, such as a cylindrical grinder, and the inner diameter can be adjusted using a known inner diameter processing machine. Lapping is performed using, for example, #1000 to 1200 SiC abrasive grains on a known lapping machine to adjust the thickness.

[0048] In manufacturing the metal blade 1, since the first sheet does not contain abrasive grains 102, the proportion of abrasive grains 102 exposed on the sides 10A and 10B of the metal blade 1 obtained after the firing, grinding and lapping processes can be reduced. So far, the first manufacturing method has been described.

[0049] (Second manufacturing method) Next, a second manufacturing method will be described. The second manufacturing method includes, in this order, a raw material powder preparation step, a laminate formation step, a sintering step, and a grinding and lapping step.

[0050] [Raw material powder production process] In the raw material powder preparation step, a first raw material powder containing mainly metal powder to become the metal bond phase 101 and no abrasive grains, and a second raw material powder containing the metal powder to become the metal bond phase 101 and abrasive grains 102 are prepared. For example, in this step, at least two types of raw material powder are prepared: a first raw material powder containing only metal powder, and a second raw material powder containing the metal powder and abrasive grains 102.

[0051] Known methods can be applied to produce the raw material powder, and for example, the metal powder and abrasive grains 102 can be mixed by rotating a container containing the raw material powder, by placing the raw material powder in a container that can be fitted with a stirring blade inside and mixing the raw material powder using the stirring blade, or by using a mixing method that utilizes a fluidized bed.

[0052] The first metal powder is, for example, one or more powders selected from the group consisting of Cu, Sn, Co, Ni, Fe, and Cu alloys.

[0053] The average particle size of the first metal powder is not particularly limited, but is preferably 5 μm or less from the viewpoint of uniform dispersibility of the material. However, the average particle size of the first metal powder may be 5 μm or more.

[0054] The second raw material powder contains a second metal powder and abrasive grains 102. The average particle size of the second metal powder is in the same range as the average particle size of the first metal powder. The second metal powder and the first metal powder may have the same composition or different compositions.

[0055] [Laminate formation process] In the second manufacturing method, this step corresponds to the molding step. In the laminate formation step, a laminate is formed consisting of a first powder layer containing at least a first metal powder, a second powder layer containing a second metal powder and abrasive grains 102 and disposed on one surface of the first metal powder layer, and a second powder layer on which the first metal powder is again disposed, with the first powder layer disposed on both surfaces of the second powder layer. Specifically, the first powder layer is formed by first charging a first raw material powder into a mold having a circular bottom surface provided in a molding device. Next, a second raw material powder is charged in a layered form on top of the first powder layer to form a second powder layer. The first raw material powder is then charged on top of the second raw material powder layer. Pressure is applied to the powders thus charged in layers. This results in a circular laminate formed by stacking the first powder layer, the second powder layer, and the first powder layer in this order. The dimensions of the laminate at this time are set taking into consideration the amount of shrinkage of the laminate in the sintering process, the cutting allowance of the laminate in the grinding and lapping process, etc. Specifically, the outer diameter of the laminate is set to be larger than the outer diameter of the metal blade 1. Also, the inner diameter of the laminate is set to be smaller than the inner diameter of the metal blade 1.

[0056] [Sintering process] In the sintering process, the metal powders constituting the laminate are heated under pressure to obtain a sintered body. The sintering atmosphere is an inert gas atmosphere, such as a nitrogen atmosphere or an argon atmosphere. The sintering temperature can be, for example, 600°C or higher and 850°C or lower. The sintering temperature may be changed within a temperature range depending on the sintering condition, taking into account the melting point of the metal powder used. The sintering time is the holding time at the set temperature, and can be, for example, 10 minutes to 30 minutes. From the viewpoint of dimensional and physical property stability, the sintering time is preferably 10 minutes or longer. The sintering process is carried out in a sintering furnace. In the sintering process, each metal powder is sintered to form a metal bond phase 101. The pressure applied to the laminate is not particularly limited, and can be, for example, 20 MPa or more and 40 MPa or less. The metal powders shrink due to heating and compression during the sintering process, causing the abrasive grains 102 in the center to bite into the metal bond phases 101 located on the sides, preventing the metal bond phases 101 on the sides from falling off.

[0057] [Grinding and lapping process] The grinding and lapping process in the second manufacturing method is the same as that in the first manufacturing method, so a detailed description will be omitted here. If the thickness dimensional accuracy after sintering satisfies the standards, the lapping process may be omitted.

[0058] In manufacturing the metal blade 1, the first powder that does not contain abrasive grains 102 is used, so it is possible to reduce the proportion of abrasive grains 102 exposed on the side surfaces 10A and 10B of the metal blade 1 after lapping. So far, the second manufacturing method has been described. [Example]

[0059] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to these examples.

[0060] (Example 1 of the present invention) As Example 1 of the present invention, a metal blade was manufactured by the following method. A rotating mixer (Thinky Corporation, Awatori Rentaro, model number: ARV-310LED) was used to disperse Cu-Sn alloy powder (average particle size 5 μm) in a dispersion medium (water-soluble cellulose as a base) to obtain a first slurry. The concentration of Cu-Sn alloy powder in the first slurry was set to 60 wt %. Using the same device, the alloy powder and abrasive grains (material: diamond, average particle size 45 μm) were dispersed in the same dispersion medium as above to obtain a second slurry. The concentration of Cu-Sn alloy powder in the second slurry was set to 60 wt %. The first slurry was applied to a release film using a doctor blade method to a thickness of 0.15 mm, and then dried at 40° C. for approximately 6 hours or more to produce a first sheet. Next, the second slurry was applied to a thickness of 0.8 mm, and then dried at 40° C. for approximately 6 hours or more to produce a second sheet. After that, the first sheet and second sheet obtained after drying were each molded into a ring shape, and the front and back of the molded second sheet were sandwiched between the molded first sheets to obtain a layered coating film. The resulting coating was then degreased by holding it in a hydrogen atmosphere at 430°C for 3 hours, and then pressure was applied to the degreased coating, which was then held in a nitrogen atmosphere at 750°C for 15 minutes to obtain a sintered body. The sintered body was subjected to inner and outer diameter machining to achieve the specified dimensions, and the thickness was adjusted by lapping using #1000 abrasive grains. The resulting metal blade had an outer diameter of 58 mm, an inner diameter of 40 mm, and a thickness of 0.32 mm.

[0061] As a comparative example, a metal blade was manufactured by the following method. First, a Cu-Sn alloy powder (average particle size 5 μm) and abrasive grains (material: diamond, average particle size 45 μm) were dispersed in a dispersion medium (based on water-soluble cellulose) using a rotary mixer (Thinky Corporation, Awatori Rentaro, model number: ARV-310LED) to obtain a slurry. The concentration of the Cu-Sn alloy powder in the slurry was 60 wt %. The slurry was applied to a release film using a doctor blade method to a thickness of 0.5 mm, and then dried for approximately 6 hours or more at 40°C. After that, a circular ring shape was cut out from the sheet obtained after drying, and two of the obtained sheets were stacked together to obtain a layered coating film. The resulting coating was then degreased by holding it in a hydrogen atmosphere at 430°C for 3 hours, and then held in a nitrogen atmosphere at 750°C for 15 minutes to obtain a sintered body. The sintered body was subjected to inner and outer diameter machining to achieve the specified dimensions, and the thickness was adjusted by lapping using #1000 abrasive grains. The resulting metal blade had an outer diameter of 58 mm, an inner diameter of 40 mm, and a thickness of 0.32 mm.

[0062] The area ratio of abrasive grains exposed from the side surface of each metal blade relative to the area of the side surface was measured using the following method. The side surface was observed at 500x magnification using a digital microscope (Keyence Corporation: VHX-6000), and abrasive grains were selected based on the observed image. Specifically, areas with metallic luster were determined to be the metal bond phase, and areas without metallic luster were determined to be areas with exposed abrasive grains. The area of each abrasive grain was calculated by counting grains of the same color. The area ratio of the abrasive grains relative to the area of the side surface in that field of view was then calculated. To cover the entire area of the side surface, images were taken from nine fields of view, and the area ratio was calculated for each image using the above method. The average area ratio was then calculated using the area ratio for each field of view. This calculated average area ratio was taken as the area ratio of exposed abrasive grains. The area ratio of the abrasive grains exposed from the side surface of the metal blade of the present invention per field of view to the area of the side surface was 2 to 9%, and the average area ratio (area ratio of abrasive grains) calculated from the area ratio per field of view was an average of 6%. The area ratio of each field of view exposed from the side surface to the side surface area of the metal blade of the comparative example was 15 to 33%, and the average area ratio of abrasive grains calculated from the area ratio of each field of view was an average of 26%.

[0063] The protruding height of the abrasive grains on the side of each metal blade was measured using the following method. Abrasive grains were identified using the above method in an image of the side surface observed with a digital microscope (Keyence Corporation: VHX-6000), the image was converted into 3D, the area containing the abrasive grains was designated with a straight line, and line roughness measurements were performed. The maximum height obtained from multiple line roughness measurements in the above field of view was taken as the maximum protruding height. The image observed with an optical microscope was converted into 3D, and line roughness measurements were performed on areas that were thought to be abrasive grains. In the metal blade of the present invention, the maximum protruding height of the abrasive grains was 2 μm. In the metal blade of the comparative example, the maximum protruding height of the abrasive grains was 16 μm.

[0064] Each metal blade was attached to the cutting device via the flange, and 1000m of BGA dummy workpiece was cut, with the cutting edge width measured every 100m. The cutting edge width was measured approximately 0.95mm from the outer surface of the metal blade in the direction of the central axis. The amount of thinning of the cutting edge was taken as the difference between the cutting edge width before and after cutting, and the results are shown in Figure 4, along with the amount of wear in the vertical direction in Figure 5.

[0065] In the metal blade of Example 1 of the present invention, the area ratio of abrasive grains exposed from the side surface to the area of the side surface was 10% or less, and when these metal blades were used, the thinning of the blade width was suppressed as shown in Figure 4. Furthermore, as shown in Figure 5, it was confirmed that the wear resistance of the metal blade in terms of the amount of vertical wear was equivalent to that of the comparative example. [Explanation of symbols]

[0066] 1 Metal Blade 11 Exterior 12 Inner 13 Through hole 10A, 10B side 101 Metal bond phase 102 Abrasive grain

Claims

1. A metal blade having a circular thin plate shape and including a metal bond phase and abrasive grains, the area ratio of the abrasive grains exposed from the surface to the area of the surface arranged at both ends in the direction along the central axis of the metal blade is 10% or less (excluding 0%), The thickness of the metal blade is 0.05 mm or more and 0.40 mm or less, A metal blade, wherein the average particle size of the abrasive grains is ¼ or less of the thickness of the metal blade, and is 0.003 mm or more and 0.10 mm or less.

2. 2. The metal blade according to claim 1, wherein the maximum height of the abrasive grains protruding from the surface in a direction along the central axis O is equal to or less than half the average grain size of the abrasive grains.

3. 3. A method for manufacturing a metal blade according to claim 1 or 2, A method for manufacturing a metal blade having a circular thin plate shape including a metal bond phase and abrasive grains, comprising: a molding step of molding a laminate containing metal powder and the abrasive grains; a sintering step of sintering the metal powder.

4. the forming step is a coating film forming step of forming a first coating film layer from a first slurry containing at least a first metal powder, forming a second coating film layer on the surface of the first coating film layer from a second slurry containing a second metal powder and the abrasive grains, and forming a third coating film layer on the surface of the second coating film layer from the first slurry containing at least the first metal powder, thereby obtaining a layered coating film; The method for manufacturing a metal blade according to claim 3, wherein the sintering step is a degreasing / sintering step of degreasing and sintering the coating film obtained in the coating film forming step.

5. the molding step is a laminate formation step of forming a laminate including a first powder layer containing at least a first metal powder, a second powder layer containing a second metal powder and the abrasive grains and disposed on one surface of the first powder layer, and a third powder layer containing at least the first metal powder and disposed on the surface of the second powder layer; The method for manufacturing a metal blade according to claim 3 , wherein the sintering step is a step of sintering the laminate to form a sintered body.

6. The method for manufacturing a metal blade according to any one of claims 3 to 5, wherein the composition of the metal powder is the same in a direction along the central axis of the metal blade.

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