Grinding stone, cutting blade, grinding wheel, and processing method

Abstract

To provide a new technique which can expand options of a grinding stone according to workpiece and a processing condition.SOLUTION: There is provided a grinding stone in which abrasive grains are bonded to each other by a binding material, wherein the binding material contains a first material, and a second material different from the first material, and the second material is fixed to the first material in an irregular net shape. The first material is made of metal, and the second material is made of a non-metal inorganic material. The first material is made of a resin, and the second material is made of a vitreous material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a grinding stone, a cutting blade, a grinding wheel, and a processing method for processing a workpiece using them. [Background technology]

[0002] Conventionally, cutting blades for cutting workpieces have been known, as disclosed in Patent Document 1, for example. In cutting blades made of a disc-shaped grinding stone with abrasive grains bonded with a binder, the binder wears under cutting load, causing the abrasive grains to fall off and new abrasive grains to protrude, a so-called self-sharpening effect, allowing the cutting blade to maintain its sharpness while performing cutting.

[0003] In order to maintain sharpness, the binder needs to wear down appropriately while cutting the workpiece. Therefore, Patent Document 1 proposes a cutting blade in which through holes and blind holes are formed in the thickness direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-164881 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the cutting blade having through holes or blind holes as disclosed in Patent Document 1, if the rigidity becomes too low, there is a risk of breakage increasing.

[0006] On the other hand, it is possible to use cutting blades made of a binder that easily wears off, but binders that easily wear off have low strength and may increase the risk of damage due to the cutting blade bending when cutting the workpiece.

[0007] Furthermore, since differences in the workpiece and processing conditions affect the processing quality, such as chipping and cracks at the cutting point, it is important to select a cutting blade made of a grinding stone with an appropriate bonding material depending on the workpiece and processing conditions.

[0008] In addition to cutting blades, it is also important to select appropriate grinding wheels, which also have grinding stones, depending on the workpiece and processing conditions.

[0009] In view of the above problems, the present invention proposes a novel technique that makes it possible to expand the options for grinding wheels according to the workpiece and processing conditions. [Means for solving the problem]

[0010] The problem to be solved by the present invention is as described above, and the means for solving this problem will now be described.

[0011] According to one aspect of the present invention, there is provided a grinding wheel in which abrasive grains are bonded with a binder, the binder including a first material and a second material different from the first material, and the second material being fixed to the first material in an irregular mesh pattern.

[0012] According to one aspect of the present invention, the first material is made of a metal, and the second material is made of a non-metallic inorganic material.

[0013] According to one aspect of the present invention, the first material is made of a resin, and the second material is made of a glass material.

[0014] According to one embodiment of the present invention, the bonding material further includes a third material different from the first material and the second material, the third material being adhered to the first material and the second material in an irregular mesh pattern, the first material being made of metal, the second material being made of glass, and the third material being made of resin.

[0015] According to one aspect of the present invention, the second materials are connected to each other and integrated together.

[0016] According to another aspect of the present invention, there is provided a cutting blade having a cutting edge made of the above grindstone.

[0017] According to another aspect of the present invention, there is provided a grinding wheel having the above grinding stone.

[0018] According to one aspect of the present invention, there is provided a processing method for producing a cut workpiece, the processing method comprising: a preparation step of preparing a cutting blade in which abrasive grains are bonded with a binder, the binder including a first material and a second material different from the first material, the second material being fixed to the first material in an irregular mesh pattern; a holding step of holding the workpiece with a holding unit; and a cutting step of cutting the workpiece held by the holding unit with the cutting blade.

[0019] According to one aspect of the present invention, there is provided a processing method for producing a ground workpiece, the processing method comprising: a preparation step of preparing a grinding wheel having abrasive grains bonded together with a binder, the binder including a first material and a second material different from the first material, the second material being fixed to the first material in an irregular mesh pattern; a holding step of holding the workpiece with a holding unit; and a grinding step of grinding the workpiece held by the holding unit with the grinding wheel. [Effects of the Invention]

[0020] The present invention provides the following effects. That is, according to one aspect of the present invention, the second material is arranged in a marbled pattern relative to the first material, and the first and second materials are present in a balanced manner around the entire circumference of the cutting edge, which reduces the likelihood of unevenness in the cutting edge's rigidity and prevents uneven processing quality during cutting. Furthermore, even as the blade wears, the exposed states of the first and second materials are not uneven, preventing uneven self-sharpening of the abrasive grains. Furthermore, because the first and second materials each contact the surfaces of the abrasive grains, the bonding characteristics at the contact surfaces between each material and the abrasive grains can be utilized. In this way, a wider range of grinding stone options are available to suit the workpiece and processing conditions.

[0021] Furthermore, according to one aspect of the present invention, the mesh-like portions of the second material are connected and integrated with each other, making it possible to form a mesh-like so-called "skeleton" from the same material, and since the second material that forms this "skeleton" is fixed to the first material, the rigidity of the cutting blade can be maintained even as the cutting blade becomes worn. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a diagram illustrating the configuration of a grindstone. [Figure 2] FIG. 4 is a schematic diagram showing an example of the second material forming an irregular mesh pattern. [Figure 3] FIG. 10 is a schematic diagram showing an example in which the second and third materials form an irregular mesh pattern. [Figure 4] (A) is a diagram showing the preparation step in cutting processing, and (B) is a diagram explaining the cutting step. [Figure 5] (A) is a diagram showing the preparation step in the grinding process, and (B) is a diagram explaining the grinding step. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows an example of a cutting blade 10 formed in a disk shape with a through hole. The cutting blade 10 shown in Fig. 1 is composed of a grinding stone 6 made by sintering abrasive grains 2 and a binder 4, and is used as a cutting blade in the form of a so-called washer blade. Alternatively, it is fixed to a hub base (not shown) and used as a cutting blade in the form of a so-called hub blade.

[0024] The cutting blade 10 made of the grinding wheel 6 is manufactured, for example, by mixing powder of the binder 4 with powder of the abrasive grains 2, molding it into a predetermined shape, and then heating and sintering it at the sintering temperature of the binder 4 while applying a predetermined pressure.

[0025] The abrasive grains 2 are made of, for example, diamond or cubic boron nitride (CBN). The grain size of the abrasive grains 2 is, for example, about #60 to #8000. The grain size is in accordance with or conforms to the JIS standards established by the Japanese Industrial Standards Committee (JISC), specifically JISR6001-1:2017 (Grain size of abrasives for grinding wheels - Part 1: Coarse grains) and JISR6001-2:2017 (Grain size of abrasives for grinding wheels - Part 2: Fine powders).

[0026] 1 shows an enlarged schematic view of the structure of a grinding wheel 6, in which abrasive grains 2 are bonded together with a binder 4, and the binder 4 includes a first material 41 and a second material 42 that is different from the first material 41. The second material 42 is fixed to the first material 41 in an irregular mesh pattern.

[0027] Here, "irregular mesh-like" refers to a three-dimensional space defined by three mutually perpendicular axial directions (X-axis, Y-axis, Z-axis), in which parts extending to a predetermined length are formed irregularly (randomly) in multiple locations.

[0028] FIG. 1 shows that there are multiple segments of second material 42 that extend continuously over a length longer than the grain size of the abrasive grains 2. For example, there are segments 42x that connect abrasive grains 2, 2 that are offset in the X-axis direction, segments 42y that connect abrasive grains 2, 2 that are offset in the Y-axis direction, and segments 42z that connect abrasive grains 2, 2 that are offset in the Z-axis direction. Furthermore, there are also locations where the second material 42 is connected to each other in segments 42n where there are no abrasive grains. The irregular arrangement of these continuous segments 42x, 42y, 42z, and 42n forms an "irregular mesh of the second material 42 relative to the first material 41."

[0029] The second material 42 forms an irregular mesh pattern on the first material 41, and thus the second material 42 is fixed to the first material 41 in a so-called "marbled" pattern. The "marbled" pattern generally refers to a speckled pattern resembling frost, and refers to a state in which a different color is irregularly and evenly distributed on a base background surface.

[0030] The second material 42 is disposed so as to cover a part of the surface of the abrasive grains 2 or the entire surface of the abrasive grains 2, and there are portions where the second material 42 comes into contact with the surface of the abrasive grains 2. There are also portions where the first material 41 comes into contact with the surface of the abrasive grains 2. That is, the first material and the second material each serve as a binder to hold the abrasive grains together.

[0031] Furthermore, for example, in one embodiment, in the second material 42, the portions 42x, 42y, 42z that form a continuous mesh shape to connect the abrasive grains 2, 2, and the portions 42a, 42b, 42c that form other mesh shapes can be connected to each other and configured as an integrated unit.

[0032] In another embodiment, a configuration can be adopted in which there are a plurality of portions where the second material 42 is integrated over a wide range, and the integrated portions are not connected to each other.

[0033] In another embodiment, the proportion of the second material 42 may be set to 50% or more of the total, so that substantially all of the second material 42 is connected without any waste and integrated.

[0034] FIG. 2 is a schematic diagram showing an example of the second material 42 forming an irregular mesh, in which abrasive grains 2 are arranged so as to fill the gaps in the mesh, and other gaps are filled with the first material (not shown).

[0035] As described above, in this embodiment, the second material 42 is marbled relative to the first material 41, and the first and second materials 41 and 42 are balanced around the entire circumference of the cutting blade 10, reducing the likelihood of uneven rigidity in the cutting blade 10 and preventing uneven processing quality during cutting. Furthermore, even as the blade wears, the exposed states of the first material 41 and the second material 42 are not uneven, preventing uneven self-sharpening of the abrasive grains 2. Furthermore, because the first material 41 and the second material 42 each contact the surface of the abrasive grains 2, the bonding characteristics at the contact surface between each material and the abrasive grains 2 can be utilized. As described above, a wide range of grinding wheel options are available to suit the workpiece and processing conditions.

[0036] Furthermore, by connecting and integrating the mesh-like parts of the second material 42 with each other, it becomes possible to form a mesh-like so-called "skeleton" from the same material, and since the second material 42 that forms this "skeleton" is fixed to the first material 41, the rigidity of the cutting blade 10 can be maintained even when the cutting blade 10 becomes worn.

[0037] In the above configuration, the first material is made of a metal, and the second material is made of a non-metallic inorganic material. The first material made of metal is, for example, copper or tin. The second material made of a non-metallic inorganic material is, for example, glass (for example, low-melting point glass (glass with a high content of boron oxide, bismuth oxide, zinc oxide, alkaline earth metal oxide, or alkali metal oxide)), polyimide, or polyether ether ketone (PEEK)). The mixing ratio of the first material and the second material contained in the binder is set appropriately in the range of, for example, 5:95 to 95:5 in volume ratio.

[0038] In the above configuration, the first material is made of resin, and the second material is made of glass. The first material made of resin is, for example, polyimide or polyetheretherketone (PEEK). The second glassy material is, for example, low-melting glass (glass with a high content of boron oxide, bismuth oxide, zinc oxide, alkaline earth metal oxide, or alkali metal oxide). The mixing ratio of the first material and the second material contained in the binder is set appropriately in the range of, for example, 5:95 to 95:5 in volume ratio.

[0039] In another embodiment, the bonding material further includes a third material different from the first material and the second material, the third material being adhered to the first material and the second material in an irregular mesh pattern, the first material being made of metal, the second material being made of glass, and the third material being made of resin.

[0040] 3 is a schematic diagram showing an example in which a third material 43 forms an irregular mesh in addition to the irregular mesh of the second material 42, and the abrasive grains 2 are arranged so that they enter the gaps between the meshes of each material. The remaining gaps are filled with the first material (not shown).

[0041] The first to third materials may be the same as those described above. The first material made of metal is, for example, copper or tin. The second glassy material is, for example, low-melting glass (glass with a high content of boron oxide, bismuth oxide, zinc oxide, alkaline earth metal oxide, or alkali metal oxide). The third material made of resin is, for example, polyimide or polyetheretherketone (PEEK). The mixing ratios of the first to third materials contained in the binder are set so that the material with the least volume ratio is 5% or more, for example.

[0042] As described above, a grinding wheel can be manufactured by combining the first and second materials contained in the binder or by combining the first to third materials depending on the workpiece and processing conditions. Then, cutting blades and grinding wheels formed from this grinding wheel can be used for processing.

[0043] As a first embodiment of the processing method, a processing method for producing a cut workpiece as shown in FIGS. 4(A) and 4(B) is used.

[0044] Specifically, as shown in Fig. 4(A), a preparation step of preparing a cutting blade is first performed. The grindstone constituting the cutting edge 10 of the cutting blade 12 has abrasive grains bound together with a binder, and the binder contains a first material and a second material different from the first material, with the second material adhered to the first material in an irregular mesh pattern. The cutting blade 12 is fixed to the tip of a spindle (not shown) provided in the cutting unit 14 and rotated at high speed by a motor (not shown).

[0045] 4(A), a holding step is performed in which the workpiece W is held by a holding unit 30. The type of workpiece W is not particularly limited, but examples include semiconductor wafers made of silicon (Si), gallium arsenide (GaAs), silicon carbide (SiC), etc., and wafers made of sapphire (Al2O3)-based inorganic material substrates. Other examples include various plate-shaped workpieces such as packaging substrates, ceramics, and glass, composite substrates made of multiple layers, and substrates made by bonding multiple substrates together. In the preparation step, cutting blades are prepared using bonding materials and abrasive grains that are optimal for the material and processing conditions of the workpiece.

[0046] The holding unit 30 is configured to include a holding table 32 having a suction holding surface 31, a clamping mechanism 33, and a processing feed mechanism (not shown). The suction holding surface 31 is connected to a suction source 34c via a suction path 34a and a valve 34b, and sucks and holds the bottom surface of the workpiece W adhered to the tape T by negative pressure. The clamping mechanism 33 clamps the annular frame F adhered to the tape T.

[0047] Next, as shown in FIG. 4(B), a cutting step is carried out in which the workpiece W held by the holding unit 30 is cut by the cutting blade 12.

[0048] Specifically, the cutting unit 14 is lowered, the cutting blade 12 is positioned at a predetermined height, and rotated at a predetermined rotation speed, while the holding unit 30 is fed horizontally for processing, thereby forming a cutting groove along a planned dividing line set in advance on the workpiece W. During processing, cutting fluid (e.g., pure water) is supplied.

[0049] In the above processing method, the grindstone that forms the cutting edge 10 of the cutting blade 12 is manufactured using a binder and abrasive grains that are optimal for the material and processing conditions of the workpiece W, thereby achieving good processing quality with reduced defects such as chipping and cracks. Furthermore, the irregular mesh structure described above allows each material that forms the binder to be present in a balanced manner, so that the cutting edge 10 can maintain a certain level of sharpness even when worn, and throughput can be improved by reducing the number of times it needs to be dressed.

[0050] As a second embodiment of the processing method, a processing method for producing a ground workpiece as shown in FIGS. 5(A) and 5(B) is used.

[0051] Specifically, as shown in Fig. 5(A), a preparation step of preparing a grinding wheel is first performed. Grinding stones 51 are arranged circumferentially at intervals on a grinding wheel 50, and abrasive grains are bonded with a binder. The binder contains a first material and a second material different from the first material, with the second material adhered to the first material in an irregular mesh pattern. The grinding wheel 50 is fixed to a mount 54a provided at the lower end of a spindle 54 provided in a grinding unit 52, and is rotated at high speed by a motor (not shown).

[0052] 5(A), a holding step is performed in which the workpiece W is held by a holding unit 60. The workpiece W is, for example, a semiconductor wafer made of silicon, and in the preparation step, a grinding wheel 50 is prepared, which includes a grinding stone 51 using a binder and abrasive grains that are optimal for the material and processing conditions of the workpiece W.

[0053] The holding unit 60 is configured to include a holding table 62 having a suction holding surface 61, and a motor (not shown) that rotates the holding table 62 in a horizontal plane. The suction holding surface 61 is connected to a suction source 64c via a suction path 64a and a valve 64b, and sucks and holds the bottom surface of the workpiece W by negative pressure.

[0054] Next, as shown in FIG. 5(B), a grinding step is carried out in which the workpiece W held by the holding unit 60 is ground by the grinding wheel 50.

[0055] 5(A), the workpiece W is held by the holding unit 60 with the back surface Wb of the workpiece W exposed upward. Then, as shown in FIG. 5(B), while grinding water is supplied to the grinding wheel from a nozzle (not shown), the holding table 62 is rotated and the grinding unit 52 is lowered to press the grinding wheel 50 against the back surface Wb of the workpiece W, whereby the back surface Wb of the workpiece W is ground and thinned, and the workpiece W is divided into chips along the half-cut grooves.

[0056] In the above processing method, the grinding stone 51 of the grinding wheel 50 is manufactured using a bond and abrasive grains that are optimal for the material and processing conditions of the workpiece W, thereby achieving good processing quality with reduced defects such as scratches. Furthermore, the irregular mesh structure described above ensures that the various materials that make up the bond are present in a balanced manner, so that a certain level of grinding quality can be maintained even when the grinding stone 51 wears, and throughput can be improved by reducing the number of times it is dressed. [Explanation of symbols]

[0057] W Workpiece Wb back side 2 abrasive grains 4 Binding material 6. Whetstone 10 cutting blade 12 cutting blades 14 Cutting unit 30 Holding Unit 31 Suction holding surface 32 Holding table 33 Clamping mechanism 34a Suction channel 34b Valve 34c suction source 41 First Material 42 Second Material 43 The Third Material 50 grinding wheels 51 Whetstone 52 Grinding unit 54 Spindle 60 Holding Unit 61 Suction holding surface 62 Holding table 64a Suction channel 64b Valve 64c suction source

Claims

1. A grinding wheel in which abrasive grains are bonded with a binder, the binder includes a first material and a second material different from the first material; The grindstone has the second material adhered to the first material in an irregular mesh pattern.

2. The first material is made of a metal, and the second material is made of a non-metallic inorganic material.

2. The grinding wheel according to claim 1.

3. The first material is made of resin, and the second material is made of glass.

2. The grinding wheel according to claim 1.

4. the binder further includes a third material different from the first material and the second material; the third material is fixed to the first material and the second material in an irregular mesh pattern; 2. The grinding wheel according to claim 1, wherein the first material is made of metal, the second material is made of glass, and the third material is made of resin.

5. 5. The grindstone according to claim 1, wherein the second materials are connected to each other and integrated into one piece.

6. A cutting blade having a cutting edge made of the grindstone according to any one of claims 1 to 4.

7. A cutting blade having a cutting edge made of the grindstone according to claim 5.

8. A grinding wheel comprising the grinding stone according to any one of claims 1 to 4.

9. A grinding wheel having the grinding stone according to claim 5.

10. 1. A machining method for producing a machined workpiece, comprising: a preparing step of preparing a cutting blade in which abrasive grains are bonded with a bonding material, the bonding material including a first material and a second material different from the first material, the second material being fixed to the first material in an irregular mesh pattern; a holding step of holding the workpiece with a holding unit; a cutting step of cutting the workpiece held by the holding unit with the cutting blade; A processing method comprising:

11. 1. A machining method for producing a ground workpiece, comprising: a preparation step of preparing a grinding wheel having abrasive grains bonded with a bond material, the bond material including a first material and a second material different from the first material, the second material being fixed to the first material in an irregular mesh pattern; a holding step of holding the workpiece with a holding unit; a grinding step of grinding the workpiece held by the holding unit with the grinding wheel; A processing method comprising:

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