JP7184464B2 - Annular grindstone manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing an annular grindstone to be attached to a cutting device.

A device chip is formed, for example, by cutting a disk-shaped wafer containing a semiconductor. For example, a plurality of intersecting dividing lines are set on the surface of the wafer, and a device such as an IC (Integrated Circuit) including the semiconductor is formed in each region partitioned by the dividing lines. Then, by dividing the wafer along the planned division lines, individual device chips are formed.

In recent years, along with the miniaturization and thinning of electronic equipment, there is an increasing demand for miniaturization and thinning of device chips mounted on the electronic equipment. In order to form a thin device chip, for example, after forming a plurality of devices on the front surface of a wafer, the back surface of the wafer is ground to thin the wafer to a predetermined thickness, and then the wafer is cut along the dividing line. split the

A cutting device with an annular grindstone (cutting blade) is used to divide the wafer. In a cutting device, an annular grindstone is rotated in a plane perpendicular to a workpiece such as a wafer to cut into the workpiece. The annular grindstone has abrasive grains and a binder in which the abrasive grains are dispersed, and the workpiece is cut by the abrasive grains appropriately exposed from the binder coming into contact with the workpiece. (See Patent Document 1).

As the cutting of the workpiece progresses, the abrasive grains fall off from the bonding material, but as the cutting edge wears, new abrasive grains are exposed one after another from the bonding material. This action is called self-sharpening, and the action of self-sharpening keeps the cutting ability of the ring-shaped grindstone above a certain level.

By the way, in optical devices such as LEDs (Light Emitting Diodes), sapphire substrates, which are excellent in mechanical and thermal properties and are chemically stable, are used. Optical device chips can be formed by forming a plurality of optical devices on a sapphire substrate and dividing the sapphire substrate for each optical device. However, the sapphire substrate is a material called a difficult-to-cut material with extremely high hardness.

For cutting difficult-to-cut materials, for example, a ring-shaped grindstone called a hub type is used, in which a grindstone portion is electrodeposited on the outer periphery of a ring-shaped base by a method such as electrolytic plating. More specifically, the ring-shaped grindstone is a ring-shaped grindstone formed by electrodepositing a bonding material such as a nickel layer in which abrasive grains such as diamond are dispersed on an aluminum base. An annular grindstone formed by electrolytic plating is also called an electrodeposited grindstone.

Electroplated whetstones having a nickel layer as a binding material have a problem in that since the abrasive grains are strongly fixed to the binding material, self-sharpening is unlikely to occur with the electroplated whetstone, and the cutting ability of the whetstone cannot be sufficiently maintained. . Therefore, in order to facilitate the self-sharpening action, a ring-shaped grindstone provided with a porous bonding material has been developed (see Patent Document 2).

JP-A-2000-87282 JP 2016-168655 A

When a work piece is cut with an annular grindstone whose bonding material has a porous structure, the bonding material is consumed and moderate self-sharpening occurs, and the cutting ability of the annular grindstone is maintained above a certain level. However, since the side surfaces of the ring-shaped grindstone are also easily worn, the strength of the ring-shaped grindstone is low. Therefore, the first layer and the second layer having a porous structure are alternately laminated, and both outermost layers exposed to the outside are the first layers. It is conceivable to form an annular grindstone with a portion.

Since the ring-shaped grindstone includes the second layer having a porous structure, the grindstone portion is more likely to be worn than a ring-shaped grindstone that does not include any layer having a porous structure, and self-sharpening due to wear is likely to occur. . On the other hand, since the first layer is also included, the strength is higher than that of the ring-shaped grindstone in which the grindstone portion is formed only by the layer having the porous structure. Furthermore, since the outermost layer of the laminated structure is the first layer, the side surface of the annular grindstone is less likely to wear.

Here, the performance of the ring-shaped grindstone including the first layer and the second layer is greatly influenced by the porosity of the porous structure of the second layer. Therefore, inspection of the second layer is desired when manufacturing the ring-shaped grindstone. However, since the outermost layer of the ring-shaped grindstone is composed of the first layer, the second layer cannot be inspected without destroying the ring-shaped grindstone.

In order to observe the second layer, for example, the ring-shaped grindstone is broken to expose the second layer. cannot be used for Therefore, new problems such as a decrease in productivity and an increase in man-hours have arisen in the method of manufacturing the annular grindstone.

The present invention has been made in view of such problems, and its object is to provide an annular grindstone portion having a grindstone portion in which a first layer and a second layer having a porous structure are alternately laminated. An object of the present invention is to provide a method for manufacturing a ring-shaped grindstone which enables inspection of the porous structure when the grindstone is manufactured.

According to one aspect of the present invention, a grindstone portion having a through-hole in the center is provided, and the grindstone portion includes a first layer and a second layer having a porous structure arranged in a penetrating direction of the through-hole. A method for manufacturing a ring-shaped grindstone having a laminated structure of a total of three or more layers, both sides of which are alternately laminated along the first layer, comprising a nickel plating solution mixed with abrasive grains, and the porous A plating bath preparation step of preparing a plating bath containing an additive that contributes to the formation of a quality structure; and applying a DC current to the nickel plating solution using the base as a cathode and the nickel electrode as an anode, thereby fixing the abrasive to the annularly exposed surface of the base with a bonding material containing nickel. a plating layer forming step of depositing a plating layer containing grains, and in the plating layer forming step, the current density of the direct current is alternately set to a current density of less than a predetermined value and a current density of the predetermined value or more. By changing to, the first layer and the second layer are alternately laminated to form the plating layer in which the outermost layer is the second layer, and the plating layer forming step After that, a porosity inspection step of imaging the outermost layer of the plating layer and acquiring information on the porosity of the porous structure of the second layer constituting the outermost layer, and after the porosity inspection step, After removing the outermost layer of the plating layer and forming the grindstone portion composed of the plating layer from which the outermost layer has been removed, and after the plating layer forming step, all of the base or A method for manufacturing an annular grindstone, further comprising a base removal step of removing a part of the plating layer and exposing all or part of the region covered by the base. be.

Preferably, in the step of removing the base, the entire base is removed to produce an annular whetstone consisting only of the whetstone portion.

Preferably, in the base removal step, a part of the base is removed to manufacture the ring-shaped grindstone composed of the grindstone portion and the base.

In the method for manufacturing an annular grindstone according to an aspect of the present invention, the annular grindstone part including a laminated structure of a total of three or more layers in which the first layer and the second layer having a porous structure are alternately arranged of whetstones are manufactured. Here, both surfaces of the grindstone portion are composed of the first layer. However, in the method for manufacturing an annular grindstone according to one aspect of the present invention, when the plating layer is laminated on the base, the outermost layer is not the first layer, but the first layer that should be the outermost layer of the grindstone portion. The layer is further laminated with a second layer. That is, let the outermost layer of this plating layer be the 2nd layer.

When the second layer is exposed to the outside, the second layer can be easily observed when obtaining information on the porosity of the porous structure of the second layer. For example, information about the porosity of the porous structure can be easily obtained by imaging the second layer. After observing the second layer, the outermost layer of the plated layer is removed to form the grindstone portion. In this case, the outermost layer of the grindstone portion is the first layer.

Thus, in the method for manufacturing an annular grindstone according to one aspect of the present invention, the second layer can be easily observed, and the outermost layer is the first layer by removing the second layer. A ring-shaped grindstone can be manufactured by forming a grindstone portion. In other words, the porous structure of the second layer can be inspected in the process of manufacturing a ring-shaped grindstone that can be used for machining a workpiece.

Therefore, according to one aspect of the present invention, when manufacturing an annular grindstone having a grindstone portion in which a first layer and a second layer having a porous structure are alternately laminated, the porous structure is inspected. A method for manufacturing an annular grindstone is provided.

FIG. 1(A) is a perspective view schematically showing an annular grindstone consisting only of a grindstone portion, and FIG. 1(B) is a perspective view schematically showing an annular grindstone composed of a grindstone portion and a base. It is a diagram. FIG. 3 is a cross-sectional view schematically showing a plating layer forming step in the manufacturing process of an annular grindstone consisting only of a grindstone portion. FIG. 3A is a cross-sectional view schematically showing the plating layer formed on the base from the plating layer forming step, and FIG. 3B is a cross-sectional view schematically showing the base removing step. . FIG. 4A is a cross-sectional view schematically showing the porosity inspection process, and FIG. 4B is an SEM photograph of the outermost layer of the plating layer on which the porosity inspection process is carried out. FIG. 5(A) is a cross-sectional view schematically showing the grindstone portion formed by the grindstone portion forming step, and FIG. 5(B) is an SEM photograph of the outermost layer of the formed grindstone portion. FIG. 4 is a cross-sectional view schematically showing a plating layer forming step in a manufacturing process of an annular grindstone composed of a grindstone portion and a base. FIG. 7A is a cross-sectional view schematically showing the plating layer formed on the base from the plating layer forming step, and FIG. 3B is a cross-sectional view schematically showing the base removing step. . FIG. 8(A) is a flowchart showing an example of the flow of each step of the method for manufacturing an annular grindstone, and FIG. 8(B) shows another example of the flow of each step of the method for manufacturing an annular grindstone. It is a flow chart.

An embodiment according to the present invention will be described. FIG. 1A is a perspective view schematically showing a ring-shaped grindstone made up of only a grindstone portion, as an example of a ring-shaped grindstone manufactured by the method for manufacturing a ring-shaped grindstone (cutting blade) according to the present embodiment. . An annular grindstone 1a shown in FIG. 1A is an annular grindstone called a washer type.

The ring-shaped grindstone 1a comprises a ring-shaped grindstone portion 3a having a through hole in the center. The ring-shaped grindstone 1a is attached to the cutting unit of the cutting device. A spindle is passed through the through-hole, and rotation of the spindle rotates the ring-shaped grindstone 1a in a plane perpendicular to the extending direction of the through-hole. When the grindstone portion 3a of the rotating annular grindstone 1a is brought into contact with the workpiece, the workpiece is cut.

In addition, the annular grindstone manufactured by the method for manufacturing an annular grindstone according to the present embodiment is not limited to this. FIG. 1(B) is a perspective view schematically showing an annular grindstone having a grindstone portion and a base. The ring-shaped grindstone 1b shown in FIG. 1B is a so-called hub-type grindstone in which a grindstone portion 3b is arranged on the outer peripheral edge of an annular base 5. As shown in FIG. The ring-shaped base 5 has a grip portion 5a held by a user (operator) of the cutting device when attaching and detaching the ring-shaped grindstone 1b to and from the cutting unit of the cutting device.

The grindstone portions 3a and 3b are formed by electrodepositing a bonding material such as a nickel layer in which abrasive grains such as diamond abrasive grains are dispersed on a base, for example. The ring-shaped grindstones 1a and 1b formed by a method such as electrolytic plating are also called electrodeposited grindstones.

The grindstone portions 3a, 3b of the annular grindstones 1a, 1b contain a binder and abrasive grains dispersed and fixed in the binder. The workpiece is cut when the abrasive grains appropriately exposed from the bonding material come into contact with the workpiece. As the cutting of the workpiece progresses, the abrasive grains fall off from the bonding material, but as the cutting edge wears, new abrasive grains are exposed one after another from the bonding material. This action is called self-sharpening, and the action of self-sharpening keeps the cutting ability of the annular grindstones 1a and 1b above a certain level.

The workpiece is, for example, a substantially disk-shaped substrate made of materials such as silicon, SiC (silicon carbide), or other semiconductors, or materials such as sapphire, glass, or quartz. For example, the surface of the workpiece is partitioned by a plurality of dividing lines arranged in a grid pattern, and devices such as ICs (Integrated Circuits) and LEDs (Light Emitting Diodes) are formed in each of the partitioned regions. ing. Finally, individual device chips are formed by dividing the workpiece along the planned division lines.

In the case of an electrodeposited grindstone using a nickel layer as a binder, abrasive grains are strongly fixed to the binder, so that self-sharpening is less likely to occur with the electrodeposited grindstone, making it difficult to sufficiently maintain the cutting ability of the grindstone. On the other hand, when a work piece is cut with a grindstone having a porous structure bonding material that easily exhibits self-sharpening action, the side surface of the grindstone is easily worn and the strength of the grindstone is reduced.

Therefore, ring-shaped grindstones 1a and 1b having grindstone portions 3a and 3b in which first layers and second layers having different structures are alternately laminated are manufactured. In the following, the structure of the grindstone portion will be described by taking a washer-type ring-shaped grindstone 1a as an example. FIG. 5(A) includes a laminated structure having a total of three or more layers in which the first layer 7 and the second layer 9 are alternately arranged, and the first layer is formed on both surfaces of the laminated structure exposed to the outside. 7 is a cross-sectional view schematically showing a grindstone portion 3a on which 7 is arranged.

Here, the first layer 7 has a porous structure including pores with a smaller diameter than the pores included in the porous structure of the second layer 9 . Alternatively, the first layer 7 does not have a porous structure. The first layer 7 having such a structure becomes a layer that has high strength and is less likely to be worn out than the second layer 9 .

Since the ring-shaped grindstone 1a includes the second layer 9 having a porous structure, compared with a ring-shaped grindstone that does not include the second layer 9 having the porous structure, self-sharpening due to consumption is reduced. easily occur. Abrasive grains 11 are dispersed in the binder constituting the grindstone portion 3a. Even when the ring-shaped grindstone 1a is used to cut a difficult-to-cut material, the grindstone portion 3a wears appropriately and new abrasive grains 11 are exposed one after another, so that the ring-shaped grindstone 1a maintains a sufficient cutting ability.

On the other hand, since the ring-shaped grindstone 1a includes the first layer 7, it has a higher strength than a ring-shaped grindstone having a grindstone portion composed only of the second layer 9. FIG. Furthermore, since the outermost layer of the grindstone portion 3a is the first layer 7 having high strength, the side surface of the annular grindstone 1a is less likely to be worn.

Here, the performance of the ring-shaped grindstone 1a including the first layer 7 and the second layer 9 greatly depends on the porosity of the porous structure of the second layer 9 . Therefore, it is desirable to inspect the second layer 9 when manufacturing the annular grindstone 1a. However, since the outermost layer of the annular grindstone 1a is composed of the first layer 7, the second layer 9 cannot be inspected without destroying the annular grindstone 1a.

In order to observe the second layer 9, for example, the ring-shaped grindstone 1a is destroyed to expose the second layer 9. Cannot be used for cutting objects. Therefore, new problems such as a decrease in productivity and an increase in man-hours have arisen in the method of manufacturing the annular grindstone 1a. Further, if the ring-shaped grindstone 1a is destroyed, the state of the second layer 9 may change due to its influence, and the inspection of the second layer 9 may not be performed appropriately.

Therefore, in the method for manufacturing an annular grindstone according to the present embodiment, information about the porosity of the porous structure of the second layer 9 is obtained without destroying the grindstone portion 3a. A method for manufacturing an annular grindstone according to this embodiment will be described below. FIG. 8A is a flow chart schematically showing an example of the flow of the method for manufacturing the annular grindstone.

The ring-shaped grindstone 1a is formed by, for example, electroplating. In the manufacturing method, first, a plating bath 2 containing a nickel plating solution 16 mixed with abrasive grains and an additive 18 that contributes to the formation of a plating layer including a layer having a porous structure is prepared. A bathtub preparation step S1 is carried out. FIG. 2 schematically shows a sectional view of the plating bath 2 prepared in the plating bath preparation step S1.

The nickel plating solution 16 is an electrolytic solution containing nickel (ions) such as nickel sulfate or nickel nitrate, and is mixed with abrasive grains such as diamond. In this embodiment, 6 L of the nickel plating solution 16 (Watt bath) containing 270 g/L of nickel sulfate, 45 g/L of nickel chloride, and 40 g/L of boric acid is used. However, the composition and usage amount of the nickel plating solution 16 can be arbitrarily set.

As shown in FIG. 2, this nickel plating solution 16 is further added with an additive 18 for promoting porosity. As the additive 18, it is preferable to use one containing a water-soluble ammonium compound having a hydrophobic group such as an alkyl group, an aryl group, or an aralkyl group.

Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl and tetradecyl. , pentadecyl, hexadecyl, heptadecyl, octadecyl, and the like.

Examples of the aryl group include a phenyl group and a naphthyl group. Aryl groups include halogen atoms such as fluorine and chlorine atoms, alkyl groups such as methyl and ethyl, haloalkyl groups such as trifluoromethyl, alkoxy groups such as methoxy and ethoxy, and substituents such as aryl groups such as phenyl. may be combined.

Examples of the aralkyl group include aralkyl groups having 7 to 10 carbon atoms such as 2-phenylethyl, benzyl, 1-phenylethyl, 3-phenylpropyl and 4-phenylbutyl. The aralkyl group may be bound with the same substituent as the aryl group.

Ammonium compounds include dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, phenyltrimethylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyltributylammonium chloride, didecyldimethyl Ammonium chloride, dodecyldimethylbenzylammonium chloride, tetradecyldimethylbenzylammonium chloride, octadecyldimethylbenzylammonium chloride, trioctylmethylammonium chloride, dodecylpyridinium chloride, benzylpyridinium chloride, bromides and sulfates thereof can be mentioned. These ammonium compounds may be used alone, or two or more of them may be mixed and used.

In this embodiment, "Top Porous Nickel RSN" manufactured by Okuno Chemical Industry Co., Ltd. is used as the additive 18, and added to the nickel plating solution 16 so as to be 1 mL/L or more and 10 mL/L or less.

After performing the plating bath preparation step S1, an immersion step S2 is performed in which the base 20a on which the grindstone portion 3a is formed by electrodeposition and the nickel electrode 6 are immersed in the nickel plating solution 16 in the plating bath 2. . The base 20a is formed in a disc shape from a metal material such as stainless steel or aluminum, and a mask 22a corresponding to the desired shape of the grindstone portion 3a is formed on the surface of the base 20a. In this embodiment, the mask 22a is formed so as to form the ring-shaped grindstone 1a.

The base 20 a is connected to the negative terminal (negative electrode) of the DC power supply 10 via the switch 8 . On the other hand, the nickel electrode 6 is connected to the positive terminal (positive electrode) of the DC power supply 10 . However, switch 8 may be arranged between nickel electrode 6 and DC power supply 10 .

Next, by using the base 20a as a cathode and the nickel electrode 6 as an anode, a DC current is passed through the nickel plating solution 16, whereby the abrasive fixed to the annularly exposed surface of the base 20a with a binder containing nickel is formed. A plating layer forming step S3 of depositing a plating layer containing grains is carried out. More specifically, a plating layer 24a (see FIG. 3A) containing abrasive grains fixed with a binder is formed on the annularly exposed surface of the base 20a that is not covered with the mask 22a.

In the plating layer forming step S3, as shown in FIG. 2, the fan 14 is rotated by the rotation drive source 12 such as a motor to stir the nickel plating solution 16, and the nickel plating solution 16 is placed between the base 20a and the DC power supply 10. The switch 8 is short-circuited. As a result, as shown in FIG. 3A, a plating layer 24a can be formed in which the abrasive grains are substantially evenly distributed in the plating layer containing nickel. When the desired thickness of the plating layer 24a is obtained, the plating layer forming step S3 ends.

In addition, in the plating layer forming step S3, the current density of the DC power source 10 is alternately changed between a current density less than a predetermined value and a current density equal to or higher than the predetermined value. Here, the current density is the current value per unit area, more specifically, the current value of the direct current with respect to the area forming the plating layer 24a (the area of the base 20a exposed by the mask 22a). .

When the plating layer 24a containing nickel is formed, a layer having a porous structure with large pore diameters is likely to be formed if a direct current is applied at a relatively high current density. The diameter of the pores of the porous structure in the formed plating layer tends to become smaller as the current density becomes lower.

Therefore, in the plating layer forming step S3, a direct current is alternately applied to a current density of less than a predetermined value and a current density of the predetermined value or more, thereby forming the first layer 7 with high strength and the porous A second layer 9 having a structure is alternately laminated. Here, the predetermined value of the current density is a value appropriately set depending on the mixing ratio of each component of the nickel plating solution 16, the structure of the grindstone portion 3a (plating layer 24a) to be formed, and the like.

Although the first layer 7 having high strength is arranged on both surfaces of the grindstone portion 3a of the annular grindstone 1a, in the plating layer forming step S3, the plating layer is arranged so that the second layer 9 is arranged as the outermost layer. 24a. That is, when the DC current starts to flow through the plating bath 2, the DC power source 10 is controlled so that the DC current has a current density less than the predetermined value. The DC power supply 10 is controlled so that the current density is equal to or higher than the predetermined value. As described above, the plating layer 24a having the second layer 9 as the outermost layer can be formed.

The outermost layer of the plating layer 24a becomes the second layer 9 when the plating layer forming step S3 is completed. In this case, the porosity of the porous structure of the second layer 9 can be evaluated by observing the second layer 9 constituting the outermost layer from the outside. Therefore, in the method for manufacturing an annular grindstone according to the present embodiment, the porosity inspection step S4 is performed after the plating layer forming step S3.

In the porosity inspection step S4, for example, the outermost layer of the plating layer 24a is imaged to acquire information about the porosity of the porous structure of the second layer 9 constituting the outermost layer. FIG. 4(A) is a cross-sectional view schematically showing how the porosity inspection step S4 is carried out. The imaging of the outermost layer of the plating layer 24a is performed by, for example, an optical microscope or a scanning electron microscope (SEM). An imaging unit 26 schematically shown in FIG. 4A is an objective lens of an optical microscope, an electron detector of an SEM, or the like.

FIG. 4B is a photograph 13a showing the surface of the plated layer 24a that was actually produced. The photograph 13a is a photograph taken by SEM. The tilt angle of the stage on which the plating layer 24a is placed during imaging was set to 45 degrees. A photograph 13a shown in FIG. 4B shows the second layer 9 having a porous structure. From the photograph 13a, it is confirmed that a plurality of abrasive grains 11 are fixed by the bonding material 15 and are exposed on the surface of the bonding material 15. FIG. According to the photograph 13a, it is confirmed that the bonding material 15 has a large number of holes 17 formed therein.

For example, by analyzing this photograph 13a and calculating the area of the pores 17 occupying the surface of the binding material 15, information on the porosity of the porous structure can be obtained. However, the method of obtaining information on the porosity is not limited to this, and may be carried out by other methods using the photograph 13a, and the plating layer 24a may be analyzed by another method without imaging the plating layer 24a. You may Moreover, the information about the porosity of the porous structure does not need to be a strictly calculated numerical value of the porosity.

Then, after performing the porosity inspection step S4, the outermost layer of the plating layer 24a is removed, and the grindstone portion forming step S5 is performed to form the grindstone portion 3a composed of the plating layer 24a from which the outermost layer has been removed. do. FIG. 5A is a cross-sectional view schematically showing the grindstone portion 3a formed in the grindstone portion forming step S5.

In the grindstone portion forming step S5, the second layer 9 constituting the outermost layer of the plating layer 24a is removed. Removal of the second layer 9 is performed, for example, by the method described below. First, a treatment tank containing aqua regia prepared by mixing concentrated hydrochloric acid and concentrated nitric acid in a volume ratio of 3:1 is prepared. In addition, the plating layer 24a is electrically connected to the positive terminal (positive electrode) of the DC power supply, and an electrode resistant to aqua regia is electrically connected to the negative terminal (negative electrode) of the DC power supply via a switch. .

Then, the plating layer 24a and the electrodes are put into the processing bath. At this time, if the base removal step S6, which will be described later, has not been performed, the plated layer 24a is put into the processing tank together with the base 20a (see FIG. 2, etc.). After that, the switch is turned on, the plating layer 24a is used as an anode, and the electrode is used as a cathode, and a direct current is passed through the aqua regia in the treatment bath, thereby forming a second layer constituting the outermost layer of the plating layer 24a. 9 is electrolyzed.

At this time, for example, the voltage of the DC power supply is set to 5 V, and a current of about 6 A is passed through the aqua regia for about 10 to 20 seconds. Then, the second layer 9 constituting the outermost layer of the plating layer 24a is removed, and the grindstone portion 3a having the first layer 7 as the outermost layer is formed. FIG. 5B is an SEM photograph obtained by imaging the outermost layer of the grindstone portion 3a actually formed in the grindstone portion forming step S5. Note that the tilt angle of the stage supporting the grindstone portion 3a was also set to 45 degrees when the image of the grindstone portion 3a was taken.

As can be understood by comparing the photograph 13b shown in FIG. 5B and the photograph 13a shown in FIG. That is, it was confirmed that the second layer 9 having a porous structure was removed by the grindstone forming step S5.

After the grindstone portion forming step S5, a base removal step S6 is performed to remove all or part of the base 20a to expose all or part of the region of the plating layer 24a covered with the base 20a. do. For example, when manufacturing an annular grindstone 1a consisting of only the grindstone portion 3a, the entire base 20a is removed. FIG. 3B is a cross-sectional view schematically showing the base removal step S6.

In the example shown in FIG. 3B, the entire base 20a is removed from the grindstone portion 3a by separating the grindstone portion 3a from the base 20a. This completes the washer-type ring-shaped grindstone 1a. The ring-shaped grindstone 1a has a grindstone portion 3a having a through hole in the center, and the grindstone portion 3a is composed of a first layer 7 and a second layer 9 having a porous structure. , and both surfaces of the grindstone portion 3a are composed of the first layers 7, which includes a total of three or more layers. An annular grindstone 1a is mounted on a cutting device and used for cutting a workpiece.

In the method for manufacturing an annular grindstone according to the present embodiment, the plating layer forming step S3 is performed to form the plating layer 24a having the second layer 9 as the outermost layer. If the second layer 9 is exposed to the outside, the second layer 9 is exposed when performing the porosity inspection step S4 for acquiring information on the porosity of the porous structure of the second layer 9. easily observable. Then, after performing the porosity inspection step S4, the grindstone portion forming step S5 is performed to form the grindstone portion 3a by removing the outermost layer of the plating layer 24a. In this case, the first layer 7 is the outermost layer of the grindstone portion 3a.

As described above, in the method for manufacturing an annular grindstone according to the present embodiment, the second layer 9 can be easily observed, and the outermost layer is the first layer 7 by removing the second layer 9. An annular grindstone 1a can be manufactured by forming a certain grindstone portion 3a. In other words, the porous structure of the second layer 9 can be inspected in the process of manufacturing the ring-shaped grindstone 1a that can be used for machining the workpiece.

It should be noted that the present invention is not limited to the description of the above embodiments, and can be implemented with various modifications. For example, in the above-described embodiment, the method for manufacturing the annular washer-type grindstone 1a has been described, but the present invention is not limited to this. According to the method for manufacturing a ring-shaped grindstone according to one aspect of the present invention, for example, a hub-type ring-shaped grindstone 1b shown in FIG. 1(B) can also be manufactured. A method of manufacturing the hub-type annular grindstone 1b will be described below.

FIG. 6 is a cross-sectional view schematically showing the plating layer forming step S3 in the manufacturing process of the ring-shaped grindstone 1b including the grindstone portion and the base. The ring-shaped grindstone 1b is formed, for example, by electrolytic plating in the plating bath 2, similarly to the ring-shaped grindstone 1a. In this manufacturing method, the plating bath preparation step S1 is performed in the same manner as in the manufacturing method of the annular grindstone 1a.

The configuration of the plating bath 2, the nickel plating solution 16, and the additive 18 is the same as in the above-described method for manufacturing the annular grindstone 1a, and thus the description thereof is omitted. However, since part of the base 20b connected to the negative electrode of the DC power supply 10 serves as the annular base 5 that supports the grindstone portion 3b of the annular grindstone 1b, the shape of the base 20b is the same as that of the annular base. The shape corresponds to 5. Also, a mask 22b having a shape corresponding to the shape of the grindstone portion 3b is formed on the surface of the base 20b. Then, the immersion step S2 and the plated layer forming step S3 are performed in the same manner as in the method for manufacturing the annular grindstone 1a described above.

Also in the manufacturing method for manufacturing the annular grindstone 1b, the plating layer forming step S3 can form the plating layer 24b (see FIG. 7A) in which the outermost layer is the second layer 9, and the porosity inspection step can be performed. Information about the porosity of the second layer 9 can be obtained by performing S4. Thereafter, the grindstone portion forming step S5 is performed to remove the second layer 9 to form the grindstone portion 3b.

Next, a base removal step S6 is performed to partially remove the base 20b to expose a part of the region of the grindstone portion 3b covered by the base 20b. In addition, as shown in FIG. 7A, the mask 22b is previously removed from the base 20b before performing the base removing step S6.

Then, as shown in FIG. 7(B), the outer peripheral region of the base 20b on the side where the grindstone portion 3b is not formed is partially etched to remove a portion of the grindstone portion 3b covered by the base 20b. expose the As a result, a hub-type ring-shaped grindstone 1b in which the grindstone portion 3b is fixed to the outer peripheral region of the ring-shaped base 5 is completed. The grip portion 5a may be formed on the annular base 5 by the etching, or may be formed in advance on the base 20b.

In the above-described embodiment, the current density of the direct current is set to less than a predetermined value to form the first layer 7 having high strength, and the current density is set to a predetermined value or more to form the second layer 9 having a porous structure. Although the case of forming is described, one embodiment of the present invention is not limited to this. Depending on the mixing ratio of each component of the nickel plating solution 16, the structure of the grindstone portions 3a and 3b to be formed, etc., the current density of the DC current is set to a predetermined value or more to form the first layer 7 with high strength, The second layer 9 having a porous structure may be formed by setting the current density to a predetermined value or higher.

Furthermore, in the above embodiment, the case where the base removal step S6 is performed after the porosity inspection step S4 and the grindstone portion formation step S5 are performed has been described. It is not limited to this. That is, as shown in the flowchart shown in FIG. 8B, the base removal step S6 may be performed after the plating layer forming step S3 is performed and before the porosity inspection step S4 is performed.

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

1a, 1b ring-shaped grindstone 3a, 3b grindstone part 5 ring-shaped base 5a grip part 7 first layer 9 second layer 11 abrasive grain 13a, 13b photograph 15 binding material 17 hole 2 plating bath 6 nickel electrode 8 switch 10 DC power supply 12 rotary drive source 14 fan 16 nickel plating solution 18 additive 20a, 20b base 22a, 22b mask 24a, 24b plating layer 26 imaging unit

Claims (3)

Equipped with a grindstone portion having a through hole in the center,
The grindstone portion has a first layer and a second layer having a porous structure alternately laminated along the direction of penetration of the through hole, and both surfaces are composed of the first layer. A method for manufacturing an annular grindstone including a laminated structure of layers or more,
a plating bath preparation step of preparing a plating bath containing a nickel plating solution mixed with abrasive grains and an additive that contributes to the formation of the porous structure;
an immersion step of immersing the nickel electrode and the base, which is partially annularly exposed, in the plating bath;
By applying a direct current to the nickel plating solution with the base as a cathode and the nickel electrode as an anode, the abrasive grains are fixed to the annularly exposed surface of the base with a binder containing nickel. A plating layer forming step of depositing a plating layer,
In the plating layer forming step, the current density of the direct current is alternately changed to a current density less than a predetermined value and a current density greater than or equal to the predetermined value, thereby forming the first layer and the second layer and are alternately laminated to form the plating layer in which the outermost layer is composed of the second layer,
After the plating layer forming step, a porosity inspection step of capturing an image of the outermost layer of the plating layer and obtaining information on the porosity of the porous structure of the second layer constituting the outermost layer;
After the porosity inspection step, a grindstone portion forming step of removing the outermost layer of the plating layer and forming the grindstone portion composed of the plating layer from which the outermost layer has been removed;
After the plating layer forming step, a base removal step of removing all or part of the base to expose all or part of the region of the plating layer covered by the base;
A method for manufacturing an annular grindstone, further comprising: A method for manufacturing an annular grindstone according to claim 1,
In the base removing step, the entire base is removed,
2. The method of manufacturing a ring-shaped grindstone according to claim 1, wherein the ring-shaped grindstone is manufactured only from the grindstone portion. A method for manufacturing an annular grindstone according to claim 1,
In the base removing step, a part of the base is removed,
2. The method of manufacturing a ring-shaped grindstone according to claim 1, wherein the ring-shaped grindstone composed of the grindstone portion and the base is manufactured.

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