TW201702004A - Grinding tool and manufacturing method thereof, and manufacturing method of ground article look for reducing manufacture time, decreasing manufacture cost and enhancing geometry precision so as to increase yield of finished products - Google Patents

Abstract

The topic of the invention is to provide a grinding tool, which is a grinding tool having high processing capability for brittle materials, capable of obtaining the ground article with smooth surface in short time, and being preferably applied in polishing and processing the brittle materials, especially for the last step of polishing (L2 step). The grinding tool of the invention is a grinding tool for polishing and processing the brittle material, in which modified Mohs scale of mineral hardness is above 8, that is formed by dispersing the adamas (Diamond) particles over a metal substrate. Moreover, the metal substrate contains the metal capable of forming hydrides. The metal substrate preferably comprises Sn-Cu series alloy containing Sn that exceeds 20 mass% but less than 60 mass%.

Description

Grinding tool, manufacturing method thereof, and method of manufacturing the same

The present invention relates to an abrasive tool for polishing a hard and brittle material.

In order to obtain various materials such as semiconductor materials and optical device materials, polishing processes for hard and brittle materials such as sapphire, tantalum carbide, and quartz have been performed in the past.

The polishing process referred to herein is, for example, a surface in which a circular platen called a polishing platen is rubbed with a plate-shaped material to adjust the thickness or parallelism, flatness, surface roughness, and the like of the plate-like body. It is usually carried out by using a polishing disk comprising fixed abrasive stones such as diamond or cubic boron nitride. Thereafter, the surface of the wafer is polished by CMP or the like using colloidal ceria or the like to process the surface of the wafer into a flat state without distortion or scratch (mirror polishing step).

The surface roughness of the object to be polished obtained by the above previous polishing process is large, so that the subsequent CMP step takes a long time such as several days.

In order to shorten the time of the CMP step, for example, between the previous polishing process and the CMP step, the final step of polishing for improving the surface smoothness is performed, and the free abrasive grains containing the diamond slurry are used, and copper is used. The grinding disc of the tin alloy is ground. The above-mentioned previous polishing step is referred to as the L1 step, whereas the polishing step of such a diamond slurry is also referred to as the L2 step.

However, in the above-mentioned L2 step, there is a problem that the diamond slurry is expensive and costly to manufacture, and it is difficult to maintain geometric precision in the form of polishing with free abrasive grains, and the peripheral portion of the obtained abrasive body of the plate-like body is likely to be so-called Collapse, shortening manufacturing time The aspects are not sufficient enough. Therefore, if the above-mentioned L2 step can be carried out using the fixed abrasive grains of diamond, the manufacturing cost can be reduced or the time can be further shortened, and it is expected to contribute to an improvement in geometric accuracy, that is, an improvement in yield.

Patent Literatures 1 to 3 disclose an abrasive tool for fixing abrasive grains using diamond or the like for the purpose of fine grinding or polishing of hard and brittle materials.

Further, in Patent Document 4, the polishing tool is not described, but a fixed abrasive grain jigsaw in which a mixed particle containing diamond abrasive grains, solder, and titanium hydride is adhered to a paste-like substance and then sintered is described.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 8-174428

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2012-178617

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2014-083611

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2010-131698

However, in order to use the fixed abrasive grains of diamond for the final step of polishing the hard and brittle material, in order to sufficiently obtain the effect of shortening the processing time, it is necessary to make the abrasive grain retaining force, especially the self-sharpening property and the abrasive grain retaining force coexist. However, as in the prior art fixed abrasive type grinding tools of Patent Documents 1 to 3, there is still room for improvement from such viewpoints, and the grinding ability of the hard and brittle materials is insufficient.

Further, Patent Document 4 describes a wire saw including a metal capable of forming a hydride, but it has not been known to use a metal capable of forming a hydride in a polishing tool and thereby improve the processing ability of a polishing tool using diamond-fixed abrasive grains. .

Accordingly, it is an object of the present invention to provide an abrasive tool that eliminates the various disadvantages of the prior art described above.

The present invention provides a polishing tool for polishing a polishing tool for hard and brittle materials having a Mohs hardness of 8 or more, and dispersing diamond particles in a metal matrix, and comprising hydrogenating in the metal matrix Metal of matter.

Moreover, the present invention provides a method of manufacturing an abrasive tool, which is a method for producing the above-described polishing tool, and includes a step of mixing diamond particles, a metal powder constituting the metal substrate or a raw material thereof, and a metal hydride; The step of press-forming the mixed powder obtained in this step; and the step of firing the press-formed molded article in a non-oxidizing atmosphere.

Moreover, the present invention provides a method of manufacturing an abrasive tool, which is a method for producing the above-described polishing tool, and includes: a step of mixing diamond particles, a metal matrix constituting the metal substrate or a raw material thereof, and a metal hydride; The step of calcining the mixed powder obtained in this step while pressing in a non-oxidizing atmosphere.

Moreover, the present invention provides a method for producing an abrasive comprising supplying a polishing liquid containing free abrasive grains to a surface of a workpiece to be polished, which is a hard and brittle material having a Mohs hardness of 8 or more, and polishing according to the first aspect. A method for producing a polishing material in which the tool is slidably contacted and polished, using a modified Mohs hardness of 12 or more and other abrasive grains other than diamond as the free abrasive grains, and the concentration of the free abrasive grains is 2% by mass or more and 40% by mass or less. As a polishing liquid.

According to the present invention, it is possible to provide a grinding tool which is preferably suitable for polishing of hard and brittle materials because of high holding power of the abrasive grains, high processing ability of the hard and brittle material, and smoothing of the surface smoothing material in a short time. .

When the polishing tool of the present invention is used in the final step of polishing, it is possible to shorten the manufacturing time, reduce the manufacturing cost, improve the geometric accuracy of the polishing product, and improve the yield.

Further, according to the manufacturing method of the present invention, the above-described polishing tool can be efficiently produced.

Further, according to the method for producing an abrasive according to the present invention, the polishing tool for obtaining a hard and brittle material having a smooth surface can be obtained in a short time by using the above-mentioned polishing tool.

1‧‧‧Two-sided processing machine

2‧‧‧Unloading plate

3‧‧‧Upper platen

4‧‧‧ Platen Support Department

5‧‧‧Base

7‧‧‧Sun gear

8‧‧‧ internal gear

9‧‧‧Carrier

10‧‧‧ Plate-like objects

11‧‧‧Cylinder

11a‧‧‧ Output rod

12‧‧‧ bracket

13‧‧‧Rotating parts

20‧‧‧ grinding tools

A‧‧‧ arrow

B‧‧‧Central Arrow

C‧‧‧ arrow

D‧‧‧ arrow

X-X‧‧‧ line

Fig. 1 is a schematic front view showing an example of a double-face processing machine used in the polishing step using the polishing tool of the present invention.

Figure 2 is a cross-sectional view taken along line X-X of Figure 1.

Fig. 3 is an example of the shape of the abrasive tool of the present invention used in the two-face processing machine of Fig. 1.

Figure 4 is a cross-sectional SEM photograph of the abrasive tool of Example 1.

Fig. 5 is a cross-sectional SEM photograph of the abrasive tool of Comparative Example 1.

Hereinafter, the present invention will be described based on preferred embodiments thereof.

The material to be polished of the polishing tool of the present invention is a hard and brittle material having a modified Mohs hardness of 8 or more. In the present invention, the hard and brittle material refers to a material which is very hard and brittle, such as glass, quartz, ceramic, various semiconductor crystalline materials, and which is not resistant to impact and fragile.

The Mohs hardness is corrected to be the hardness of the hardness based on the damage caused by the standard substance. The softness is specified in the order of 1 to 15 standard materials. As a specific standard substance, the Mohs hardness is 1 for talc, 2 for gypsum, 3 for calcite, 4 for fluorite, 5 for apatite, and 6 for feldspar. 7 is fused silica, 8 is quartz, 9 is yellow crystal, 10 is garnet, 11 is molten zirconia, 12 is fused alumina, 13 is lanthanum carbide, 14 is boron carbide, and 15 is diamond. For example, when the sample is scraped with the fluorite of the standard material 4, the sample is not damaged, and the sample is damaged by the apatite scrap of the standard substance 5, indicating that the sample is harder than 4 and softer than 5, as a modification. The hardness is marked as "4.5". In addition, when the sample and the fluorite were damaged by scratching with the fluorite of the standard material 4, the sample had the same hardness as the standard material 4, and the modified Mohs hardness was recorded as "4". The value of the modified Mohs hardness is, after all, the relative, not the absolute value. Corrected Mohs hardness of hard and brittle materials can be used in Mohs hard The meter is measured by a usual method.

Specific examples of the hard and brittle material having a Mohs hardness of 8 or more include sapphire (corrected Mohs hardness 12), quartz (modified Mohs hardness 8), SiC (modified Mohs hardness 13), and alumina (corrected Mohs) Hardness 12) and so on.

From the viewpoint of effectively exerting the effects of the present invention, the modified Mohs hardness of the hard and brittle material is preferably 13 or less.

The abrasive tool of the present invention disperses diamond particles into a metal matrix and contains a metal capable of forming a hydride in the above metal matrix.

First, the abrasive particles, that is, the diamond particles, will be described.

The shape of the diamond particles is not limited. In the present invention, as the particle diameter of the diamond particles, the average particle diameter is 1 μm or more, which is preferable from the viewpoint of improving the processing ability of the polishing tool. Moreover, as the particle diameter of the diamond particles, the average particle diameter is 20 μm or less, and it is preferable from the viewpoint of improving the surface roughness of the object to be polished. From these viewpoints, the particle diameter of the diamond particles is more preferably an average particle diameter of 2 μm or more and 16 μm or less, and still more preferably an average particle diameter of 4 μm or more and 12 μm or less.

The average particle diameter of the diamond particles can be obtained by, for example, resin-filling the grinding tool, cutting it with a diamond knife, and observing the cut surface using a scanning electron microscope (for example, a magnification of 1000 times) for 200 particles. The measurement of the Freit diameter was performed and the average value was calculated.

When the content of the diamond particles is less than 0.1% by mass, the grinding tool of the present invention is difficult to obtain the effect of shortening the processing time, and the content of the diamond particles in the grinding tool exceeding 10% by mass is also difficult to obtain. Shorten the processing time effect. From this viewpoint, the content of the diamond particles in the polishing tool is preferably 0.1% by mass or more and 10% by mass or less, more preferably 1% by mass or more and 5% by mass or less. The content of the diamond particles in the grinding tool is such that the metal matrix in the grinding tool is dissolved in an acid, and the amount of residual diamond is determined.

In the present invention, a metal matrix is used as a binder matrix for bonding abrasive grains, that is, diamond particles. Metals can form a brittle bond that promotes self-sharpening. Examples of the metal constituting the metal matrix of the binder of the polishing tool include a Cu-Sn-based alloy, a Cu-P-based alloy, a Ni-Sn-based alloy, a Cu-based alloy, a Ni-based alloy, a Co-based alloy, and a Fe-based alloy. These may be used alone or in combination of two or more. Among these, a Cu-Sn-based alloy is preferred from the viewpoint of enhancing the effects of the present invention. Here, the Cu-Sn alloy is an alloy of Cu and Sn, and may contain one or more other sub-elements in addition to Cu and Sn. Examples of the secondary element other than Cu and Sn in the Cu-Sn-based alloy include nickel, phosphorus, cobalt, titanium, chromium, vanadium, and the like. These auxiliary elements may contain one type or two or more types. Further, in the Cu-Sn-based alloy, unavoidable impurities may be contained.

As the Cu-Sn-based alloy, those having a Sn content of more than 20% by mass are preferable. The reason for this is that a Cu-Sn-based alloy having a Sn content of more than 20% by mass is preferable in that it is hard and brittle. When the brittleness of the metal matrix is high, it is preferred because it promotes the sharpness of the diamond particles. Further, when the hardness of the metal substrate is high, it is preferable to process the hard and brittle material to make the diamond particles bite into the hard and brittle material. Therefore, when a substrate containing a Cu-Sn-based alloy having a Sn content of more than 20% by mass is used as the metal substrate, the abrasive tool of the present invention can process the hard and brittle material more stably and efficiently. Further, as the Cu-Sn-based alloy, the Sn content of 60% by mass or less is preferable from the viewpoint of suppressing the excessive brittleness of the polishing tool. From these viewpoints, the Sn content in the Cu—Sn-based alloy is more preferably 30% by mass or more and 58% by mass or less, and particularly preferably 45% by mass or more and 55% by mass or less.

The Cu content of the Cu-Sn-based alloy is preferably 40% by mass or more and less than 80% by mass, more preferably 45% by mass or more and 55% by mass or less, and particularly preferably 48% by mass or more and 52% by mass or less. The Sn content and the Cu content in the Cu-Sn-based alloy can be measured, for example, by an ICP emission spectrometer.

In the grinding tool of the present invention, the metal content constituting the metal substrate is 70% by mass. Above, it is preferable from the viewpoint of maintaining the diamond particles. Further, in the polishing tool of the present invention, the metal content of the metal matrix is 98% by mass or less, and it is preferable from the viewpoint of securing a certain amount of diamond or a metal capable of forming a hydride. From these viewpoints, the metal content of the metal matrix in the polishing tool is more preferably from 75% by mass to 96% by mass, particularly preferably from 80% by mass to 92% by mass. Further, the content of the metal constituting the metal matrix herein is the content of the alloy when the metal matrix contains the above various alloys, and the amount of the sub-element when the alloy contains the above-mentioned sub-element. However, the metal content constituting the metal matrix herein is not included in the content of the metal constituting the metal hydride. The metal content of the metal substrate constituting the polishing tool may be measured by a method of dissolving the polishing tool with an acid such as nitric acid, and quantifying the concentration of a metal such as Sn or Cu in the dissolved solution by an ICP emission spectrometer or the like.

When the polishing tool of the present invention contains nickel, it is preferable from the viewpoint of improving the formability of the polishing tool. Nickel may be dispersed in the metal matrix of the abrasive tool of the present invention or alloyed with the metal constituting the matrix. The content of nickel in the polishing tool is preferably from 1% by mass to 10% by mass, and more preferably from 2% by mass to 6% by mass, from the viewpoint of improving the moldability and the effect of the present invention. The nickel content in the polishing tool may be measured by a method of dissolving the polishing tool with an acid such as nitric acid, and quantifying the concentration of Ni in the dissolved solution by an ICP emission spectrometer or the like.

The abrasive tool of the present invention is one that contains a metal that can form a hydride. As a metal capable of forming a hydride, it is preferable to treat it easily in the atmosphere, and in addition to titanium (Ti) which is a metal which can form titanium hydride (TiH ₂ ), lithium (Li) and sodium (Na) are mentioned. Titanium is preferred. Such metals have not been used in conventional diamond abrasive fixed abrasive tools. The inventors of the present invention have actively studied a binder matrix which is self-sharpening and has good retention of abrasive grains as a binder matrix for a diamond-fixed abrasive-type abrasive tool, and found in a metal matrix. A binder matrix containing a metal capable of forming a hydride has such characteristics. The metal capable of forming a hydride used in the present invention is obtained by a decomposition reaction of a metal hydride which is usually accompanied by firing by a polishing tool. The effect of the present invention is particularly high when the metal matrix contains a Cu-Sn-based alloy having a Sn content of more than 20% by mass and less than 60% by mass. In order to make the abrasive tool of the present invention contain a metal capable of forming a hydride, as in the method for producing a polishing tool of the present invention to be described later, the metal matrix or the metal powder used as a raw material used in the production of the polishing tool is contained. Metal hydride can be used. The metal forming the hydride may be substantially uniformly dispersed into the metal matrix, or may be biased toward a portion of the metal matrix, such as the periphery of the diamond particles. In the polishing tool of the present invention, the form of the metal capable of forming a hydride is not limited, and may be, for example, a metal or a carbide. The morphology of the carbide is believed to be due to the reaction with diamond.

In the polishing tool of the present invention, when the metal forming the hydride is contained in an amount of 1% by mass or more, it is preferable from the viewpoint of enhancing the holding power of the abrasive grains. Further, when the metal content of the hydride to be formed in the polishing tool is 10% by mass or less, it is preferable from the viewpoint of press formability of the tool. From these viewpoints, the metal content of the hydride to be formed in the polishing tool is more preferably 1% by mass or more and 10% by mass or less, and particularly preferably 3% by mass or more and 8% by mass or less. The content of the metal in which the hydride can be formed in the polishing tool can be measured by dissolving the polishing tool with an appropriate acid, and measuring the concentration of Ti, Li, Na, or the like in the dissolved solution by an ICP emission spectrometer or the like. The amount of metal which can be formed into a hydride as mentioned herein is an amount in terms of metal.

The polishing tool of the present invention may contain any component other than diamond, a metal constituting the metal matrix, and a metal capable of forming a hydride, to the extent that the effects of the present invention are not impaired. The other optional component is, for example, carbon, talc, hBN or the like, and the total amount of the other optional components is preferably 10% by mass or less, and more preferably 5% by mass or less, in the polishing tool.

In particular, the amount of carbon other than diamond in the polishing tool of the present invention is less preferred from the viewpoint of improving the grinding ratio, and is preferably 10% by mass or less, more preferably 5% by mass or less in the polishing tool. The smaller the amount of carbon, the better, and it is best not to contain carbon. The amount of carbon other than diamond in the grinding tool can be measured, for example, by an infrared absorption method.

The shape of the abrasive tool of the present invention is not particularly limited, and the same shape as the previous abrasive tool used for the polishing disk is employed. The shape of the grinding tool used for the polishing disk (rotary platen) varies, for example, depending on the type of the polishing disk. For example, when the polishing disk is a type of particulate matter in which a large number of small particles are fixed on the running-in surface, the wafer shape, Bow shape, cube shape, column shape, etc. Further, for example, when the polishing disk is of a general type in which the surface grinding surface itself is formed by the polishing body, an annular shape, a disk shape, or the like is exemplified. The abrasive tool of the present invention can be used in any type of polishing disk, and the shape of the polishing tool can be any of the above.

Next, a preferred method of manufacturing the polishing tool of the present invention will be described.

The production method of the present invention may be any one of the following (1) and (2).

(1) A method of producing an abrasive tool comprising: a step of mixing diamond particles, a metal powder constituting a metal substrate or a raw material thereof, and a metal hydride (hereinafter also referred to as step A); and mixing which is obtained by the step Powder molding press molding, followed by a step of firing the press-formed molded article in a non-oxidizing atmosphere (hereinafter also referred to as a B1 step).

(2) A method for producing a polishing tool comprising the step A described above and a step of pressing a mixed powder obtained by the step of forming an A product in a non-oxidizing atmosphere (hereinafter also referred to as a step B2).

First, the A step will be described. As the preferable particle diameter of the diamond used in the step A, the above particle diameter is listed. The preferred blending amount of the diamond particles in the mixed powder is the same as the content of the diamond particles preferably selected from the above-mentioned polishing tools. Specifically, it is preferably 0.1% by mass or more and 10% by mass or less, more preferably in the mixed powder. It is 1% by mass or more and 5% by mass or less.

Examples of the metal constituting the metal matrix among the metal powders constituting the metal matrix or the raw material thereof used in the step A are the same as those exemplified as the metal constituting the metal matrix. The metal powder which is a raw material of the metal constituting the metal matrix may, for example, be a powder of Cu powder, Sn powder or other auxiliary material when the metal of the metal matrix is, for example, a Cu-Sn-based alloy. In the production method of the present invention, it is preferred to constitute a metal matrix or a raw material thereof. The metal powder contains a metal constituting a metal matrix. The preferred blending amount of the metal powder constituting the metal matrix or the raw material thereof in the mixed powder used in the step A is the same as the preferred blending amount of the metal constituting the metal matrix in the grinding tool, specifically, The mixed powder is preferably 70% by mass or more and 98% by mass or less, more preferably 80% by mass or 92% by mass or less.

In the case where the metal substrate of the grinding tool is set to include a Cu-Sn-based alloy, in the manufacturing method of the present invention, the Sn content in the total amount of the metal powder constituting the metal matrix or the raw material thereof in the mixed powder is compared. The preferred range is the same as the above-mentioned range as the preferable Sn content in the Cu-Sn-based alloy, and is preferably more than 20% by mass and less than 60% by mass, more preferably 45% by mass or more and 55% by mass or less. It is particularly preferably 48% by mass or more and 52% by mass or less.

For example, when the metal substrate in the grinding tool of the present invention is made to contain a Cu-Sn-based alloy containing more than 20% by mass of Sn and less than 60% by mass, as a constituent metal substrate used in the step A or as a raw material thereof The metal powder is a mixture of a Cu-Sn-based alloy powder having a Sn content of more than 20% by mass and less than 60% by mass, or a mixture of Sn powder and Cu powder in an amount of more than 20% by mass of Sn, which is less than 60% by mass. Alternatively, a mixture of the Cu-Sn-based alloy powder and the Sn powder and/or the Cu powder may be mixed so that the amount of Sn exceeds 20% by mass and is less than 60% by mass. The metal matrix constituting the metal substrate or the raw material thereof used in the step A of the case where the metal substrate in the abrasive tool of the present invention contains a Cu-Sn-based alloy containing more than 20% by mass of Sn and less than 60% by mass. In a preferred blending ratio, the total amount of Sn powder and Cu powder is set to 20 parts per 100 parts by mass of the Cu-Sn-based alloy powder (particularly, Cu-Sn-based alloy powder having a Sn content of more than 20% by mass and less than 60% by mass). The mass portion is not more than 98 parts by mass, and is preferably from the viewpoint of moldability and the like, and more preferably from 25 parts by mass to 92 parts by mass.

In the case where the polishing tool contains Ni, the Ni powder in the mixed powder preferably contains 1% by mass or more and 10% by mass or less, more preferably 2% by mass or more and 6% by mass. %the following.

Examples of the metal hydride in the step A include the above-described titanium hydride (TiH ₂ ) or lithium hydride (LiH). By mixing and firing such a metal hydride with a metal powder constituting a metal substrate or a raw material thereof, the grinding of the present invention which maintains the self-sharpening ability based on the brittleness of the metal substrate and improves the holding power of the abrasive grains can be easily obtained. tool. From the viewpoint of further improving the abrasive grain holding power of the polishing tool of the present invention, the amount of the metal hydride in the mixed powder of the step A is preferably 1% by mass or more. On the other hand, when the amount of the metal hydride is suppressed to a certain level or less, it is preferable from the viewpoint of press formability of the tool. Therefore, the amount of the metal hydride in the mixed powder of the step A is preferably 10% by mass or less. From these viewpoints, the amount of the metal hydride in the mixed powder of the step A is more preferably 1% by mass or more and 10% by mass or less, particularly preferably 3% by mass or more and 8% by mass or less.

Moreover, the molding method of press molding in the step B1 includes a die press molding method, a die press method (hydrostatic molding method), or a resistance sintering method. As a pressure when the pressure molding is preferably 4000kgf / cm ² or more 5000kgf / cm ² or less, more preferably 4200kgf / cm ² or more 4800kgf / cm ² or less.

In the step B1, the press-formed molded product is thereafter fired in a non-oxidizing atmosphere. Oxidation of the constituent metal of the diamond or metal matrix can be prevented by firing in a non-oxidizing atmosphere. As the non-oxidizing atmosphere, an inert atmosphere such as argon gas or nitrogen gas is used in addition to a reducing atmosphere in which a hydrogen gas or an ammonia decomposition gas is diluted with nitrogen. The holding temperature of the firing is preferably 640 ° C or more from the viewpoint of alloying, and is preferably 690 ° C or less from the viewpoint of the shape of the tool after sintering, and from these viewpoints, the holding temperature of the firing is further increased. Preferably, it is 640 ° C or more and 690 ° C or less, and particularly preferably 645 ° C or more and 660 ° C or less. Moreover, the holding time of the holding temperature is preferably 0.5 hours or more and 8 hours or less, more preferably 2 hours or more and 7 hours or less.

The method of the above (1) is high in the productivity of the polishing tool, and is preferable because it is easy to mass-produce. However, as in the method of the above (2), the mixed powder obtained by the step A can be formed by press molding and then fired. Rather, it is fired in a non-oxidizing atmosphere while being pressurized (step B2). The abrasive tool of the present invention is manufactured. The firing in the step B2 can be carried out by a hot press method or the like.

Next, an embodiment of a method for producing a preferred abrasive using the polishing tool of the present invention will be described with reference to Figs. 1 to 3 . The manufacturing method of the present invention is a method for producing a polishing material comprising a step of sliding a surface of the object to be polished, which is a hard and brittle material having a modified Mohs hardness of 8 or more, in contact with the polishing tool of the present invention.

In Fig. 1, an example of a processing machine used in the polishing step using the abrasive tool of the present invention is shown. The double-sided processing machine 1 shown in FIG. 1 includes a lower pressing plate 2, a pressure plate 3 disposed above the lower pressing plate 2, and a platen support that contacts the upper platen 3 and supports the upper platen 3. The fourth part is configured.

As shown in FIG. 1, the upper platen 3 is rotatably attached to the front end of the output rod 11a of the cylinder 11 via the bracket 12. The upper platen 3 can be raised and lowered by the cylinder 11 and, when lowered, is fastened to the groove of the rotating member 13 which is converted in the direction of the arrow D shown in FIG. 2 in the side of the base 5, and is rotated in the same direction. Further, on the lower surface of the upper platen 3, the grinding tool 20 of the present invention is disposed. In the example shown in the drawings, the platen 3 is of a type of particulate matter, that is, the grinding tool 20, for example, a cylindrical small particle as shown in FIG. 3 is fixed to the upper platen at a specific interval as shown in FIG. 3 under the surface. However, the shape of the grinding tool and the arrangement of the pressure plate as described above are not limited thereto. The upper platen 3 is fastened to the platen support portion 4 by bolts (not shown), and is rotatably provided together with the platen support portion 4.

As shown in Fig. 2, the lower platen 2 is rotatably provided on the base 5 in the direction of the arrow A, and the grinding tool 20 of the present invention is disposed on the upper surface thereof in the same manner as the upper platen 3. Further, in the lower platen 2, four sun gears 7 that rotate in the direction of the center arrow B are arranged, and the internal gears 8 that rotate in the direction of the arrow C on the outer peripheral side are meshed, and the planetary gears that rotate on one side of the revolution are rotated. Carrier 9. Further, a plate-shaped body, that is, a workpiece 10 containing a hard and brittle material is provided in each of the eight holes provided in each of the carriers 9.

Between the upper platen 3 and the lower platen 2, a coolant or free abrasive grain can be supplied in a specific amount by a hole provided in the upper platen or a slurry supply pipe (none of which is shown). The slurry. Then, the upper platen 3 is lowered by the air cylinder 11, and the workpiece 10 that is integrally operated with the carrier 9 is bonded to the lower platen 2 and the upper platen 3 to be polished.

The polishing step conditions of this embodiment are generally as follows. That is, the processing pressure is preferably 0.05kgf / cm ² or more 0.3kgf / cm ² or less, more preferably 0.15kgf / cm ² or more 0.25kgf / cm ^2. The number of rotations of the platen under the double-face processing machine depends on the size of the processing machine. However, for example, in the case of a two-face machine using a 9B machine manufactured by HAMAI, it is preferably 10 rpm or more and 30 rpm or less, more preferably 15 rpm or more and 25 rpm or less.

The hard and brittle material of the polishing tool 20 of the present invention may be a dry type or a wet type which is supplied to a polishing liquid containing a cooling liquid or a free abrasive grain. When the polishing slurry containing the free abrasive grains is supplied while sliding the abrasive tool 20 of the present invention into contact with the workpiece 10, the hard and brittle material is stabilized by the self-sharpening property of the diamond particles in the polishing tool. Processing becomes easier and better. In the method for producing an abrasive according to the present invention, the main body to be polished is the abrasive tool of the present invention using diamond-fixed abrasive grains, and the free abrasive particles are auxiliary agents for improving the polishing efficiency. In the case where the metal matrix particularly used in the abrasive tool of the present invention contains a Cu-Sn-based alloy in combination with the free abrasive grains, it exerts a high effect in promoting the shortening of the processing rate of the abrasive tool.

As the free abrasive grains, those having a modified Mohs hardness of 6 or more may be used, and those having a Mohs hardness of 12 or more are preferably used. The free abrasive grains are preferably cerium carbide (modified Mohs hardness 13), alumina (modified Mohs hardness 12), and more preferably cerium carbide from the viewpoint of self-sharpening action. When the average particle diameter of the free abrasive grains is small, particularly when it is smaller than the average particle diameter of the diamond particles of the polishing tool, it is preferable to prevent damage to the workpiece. Further, when the average particle diameter of the free abrasive grains is a certain size or more, it is preferable from the viewpoint of the durability of the processing. From these viewpoints, the average particle diameter of the free abrasive grains is preferably 0.1 μm or more and 20 μm or less, more preferably 1 μm or more and 8 μm or less, and particularly preferably 2 μm or more and 4 μm or less. The average particle diameter can be measured by a laser particle size distribution meter. As research The concentration of the free abrasive grains is usually 40% by mass or less. The concentration of the free abrasive grains using the polishing liquid is particularly preferably less than 20% by mass, which is preferable from the viewpoint of reducing the production cost or reducing the disposal cost. Further, when the free abrasive concentration of the polishing liquid is 2% by mass or more, it is preferable from the viewpoint of favorably promoting the sharpness of the diamond particles in the polishing tool. From these viewpoints, the concentration of the free abrasive grains in the polishing liquid is more preferably 5% by mass or more and 20% by mass or less, and particularly preferably 5% by mass or more and 10% by mass or less. The supply flow rate of the polishing liquid depends on the size of the processing machine. However, in the case of using a two-side processing machine of a 9B machine manufactured by HAMAI, for example, it is preferably 1000 cc/min or more and 10000 cc/min or less, more preferably 3,000 cc/min or more and 5000 cc/ Min below.

As the dispersion medium of the free abrasive grains of the polishing liquid, water, a mixture of water and an organic solvent, or the like can be used without particular limitation. As the organic solvent, those which are preferably aqueous, for example, various water-soluble grinding oils (coolant) such as a soluble or latex type can be used.

The polishing using the polishing tool of the present embodiment replaces, for example, part or all of the final step (L2 step) of polishing of the polishing platen previously using the diamond slurry and the Cu-Sn-based alloy, whereby the hard and brittle material can be greatly shortened. The processing time, the manufacturing cost are reduced, the geometric accuracy of the workpiece to be obtained of the hard and brittle material is improved, and the yield is improved.

Examples of the abrasive of the hard and brittle material produced by using the polishing tool of the present invention include various substrates or optical lenses used in a semiconductor device or an optical device. For example, when the hard and brittle material is sapphire, a substrate for epitaxial growth of a nitride-based compound semiconductor represented by gallium nitride (GaN), an SOS substrate on which Si is formed, and a polarizer for a liquid crystal projector are used. Plate, cover glass, etc.

[Examples]

Hereinafter, the present invention will be described in more detail by way of examples. However, the scope of the invention is not limited to the embodiments. Unless otherwise stated, "%" and "parts" refer to "% by mass" and "parts by mass" respectively.

[Example 1]

(1) Manufacturing of grinding tools

72 parts of Cu-Sn powder, 10 parts of Sn powder, and 10 parts of Cu powder, and 3 parts of diamond particles having an average particle diameter of 9 μm, 3 parts of Ni powder, and 3 parts of Ni powder, which are metal powders constituting a metal substrate or a raw material thereof. Mixing TiH ₂ 5 parts to obtain a mixed powder. The Cu-Sn powder is an alloy powder obtained by atomizing Cu and Sn at a mass ratio of 1:1. The obtained mixed powder was pressure molded. The press molding was carried out in a cylindrical mold having a diameter of 7 mm and a height of 10 mm so that the density of the raw material became 6.0 g/cm ³ , and then pressed at a pressure of 4,600 kgf/cm ² . Thereafter, the press-formed molded product is fired in a non-oxidizing atmosphere. As a non-oxidizing atmosphere, hydrogen gas (hydrogen gas concentration: 30% by volume) was diluted with nitrogen. The temperature at the time of firing was 645 ° C, and the holding time of this temperature was 3 hours. By the above steps, the grinding tool of Example 1 was obtained. The obtained polishing tool was confirmed to contain Cu-Sn-based alloy powder containing 89% by mass of Cu and 50% of Sn in an amount of 50% by an ICP emission spectrometer. Further, Ti derived from TiH ₂ was detected in the form of TiC in the polishing tool.

The resulting abrasive tool was cut by a diamond knife and gold sputter was deposited on the resulting cross section. Next, a cross section was taken with a scanning electron microscope (S-4700, manufactured by HITACHI Co., Ltd.) under the conditions of an acceleration voltage of 2.5 kV and a magnification of 5000 times.

(2) Evaluation of grinding

The polishing tool of the first embodiment uses the double-face processing machine 1 (manufactured by HAMAI Co., Ltd. 9B machine) shown in Fig. 1 and Fig. 2, and is supplied from the cooling liquid holes of the upper platen 3 and the lower platen 2, and is supplied with free The abrasive slurry is ground and the abrasive tool 20 is brought into sliding contact with the workpiece 10 for grinding. The polishing step for the following conditions was carried out for 60 minutes. The processing rate of the object to be cut is shown in Table 1. The processing rate referred to herein represents the amount of material removed per minute.

<grinding conditions>

Object to be polished 10: Disc-shaped sapphire wafer (thickness 1 mm, diameter 50 mm)

Processing pressure: 0.18kgf/cm ²

Number of rotations of the lower platen on the two-sided processing machine: 20 rpm

Free abrasive grains: niobium carbide (corrected Mohs hardness 13), average particle size 4 μm

Free abrasive particle concentration in the slurry: 10% by mass

Supply flow rate of slurry: 5000cc/min

Dispersion medium in the polishing liquid: A water-soluble grinding oil agent ("DIACUT W" manufactured by Yachiyo Micro Science Co., Ltd.) was diluted in water by 10 times in a volume ratio.

[Comparative Example 1]

In the "(1) Manufacture of the polishing tool" of the first embodiment, the polishing tool of Comparative Example 1 was produced in the same manner as in Example 1 except that TiH _{2 was} not added. An SEM photograph of the cross section of the polishing tool of Comparative Example 1 was obtained under the same conditions as in Example 1. The resulting SEM photograph is shown in Figure 5. Moreover, the obtained polishing tool of Comparative Example 1 was subjected to the same evaluation as "(2) Evaluation of polishing" of Example 1. The results are shown in Table 1.

[Comparative Example 2]

In addition to being Cu-Sn powder, an alloy powder obtained by atomizing Cu and Sn at a mass ratio of 77:23 was used, and the amount of Sn powder was set to 23 parts, the amount of Cu powder was set to 77 parts, and TiH _{2 was} not added. The polishing tool of Comparative Example 2 was obtained in the same manner as in Example 1 except for the above. The obtained abrasive tool was subjected to the same evaluation as "(2) Evaluation of grinding" of Example 1. The results are shown in Table 1.

As can be seen from a comparison between Fig. 4 and Fig. 5, in the photograph of the cross section of the polishing tool of Comparative Example 1 of Fig. 5, it was found that the diamond particles emitted white light. This is shown in Comparative Example 1, in which the surface of the diamond particles was exposed. On the other hand, in the photograph of the cross section of the polishing tool of the photographing example 1 of Fig. 4, this portion is not seen, and the projection corresponding to the diamond particles is cover. From this, it was judged that in Comparative Example 1, the wettability of the diamond particles and the surrounding metal matrix was inferior, and the diamond particles were observed to be exposed. In contrast, in the polishing tool of Example 1, by using a metal capable of forming a hydride, the diamond particles were used. The wettability of the metal matrix is improved, and the retention of the diamond particles in the metal matrix is improved. 4 and 5 are cross-sectional photographs as described above, but since either of them is a photograph of a portion facing the gap in the polishing tool, the difference in the surface state of the diamond particles is clearly shown.

Further, from the results of the above Table 1, in particular, from the comparison between Example 1 and Comparative Example 1, it was judged that the processing capability of the polishing tool containing the metal capable of forming a hydride was greatly improved, and the processing time of the hard and brittle material was greatly shortened. Therefore, the grinding tool of the present invention has high processing ability of hard and brittle materials, and can realize stable processing of hard and brittle materials, and can substantially shorten the processing of hard and brittle materials by replacing part or all of the final step of polishing (L2 step). Time, reducing manufacturing costs, improving the geometric accuracy of the obtained hard and brittle material and improving the yield.

[Embodiment 2]

In the present embodiment, the polishing tool manufactured in "(1) Manufacturing of grinding tool" of [Example 1] was processed using SiC. As the workpiece 10, a disk-shaped SiC wafer (thickness: 1 mm, diameter: 50 mm) was used. Further, the processing pressure was set to 0.20 Kgf/cm ² . Further, the concentration of the free abrasive grains in the polishing liquid was set to 5% by mass. Except for these aspects, the same method of polishing was carried out under the same conditions as in Example 1. As a result, the processing rate was 1.12 μm/min.

1‧‧‧Two-sided processing machine

2‧‧‧Unloading plate

3‧‧‧Upper platen

4‧‧‧ Platen Support Department

5‧‧‧Base

11‧‧‧Cylinder

11a‧‧‧ Output rod

12‧‧‧ bracket

13‧‧‧Rotating parts

X-X‧‧‧ line

Claims (10)

An abrasive tool for polishing a hard and brittle material having a Mohs hardness of 8 or more, wherein the diamond particles are dispersed in a metal matrix, and the metal matrix contains a metal capable of forming a hydride. The abrasive tool of claim 1, wherein the metal matrix comprises a Cu-Sn-based alloy containing more than 20% by mass of Sn and less than 60% by mass. The abrasive tool of claim 1, which is used in combination with a polishing liquid containing free abrasive grains, and the free abrasive particles are abrasive grains other than diamond. The abrasive tool according to claim 1, wherein the diamond particles have an average particle diameter of from 1 μm to 20 μm. The abrasive tool according to claim 1, wherein the diamond particles are contained in an amount of 0.1% by mass or more and 10.0% by mass or less. The polishing tool according to claim 1, wherein the metal constituting the metal substrate contains 70% by mass or more and 98% by mass or less. The polishing tool according to claim 1, wherein the metal forming the hydride is contained in an amount of 1% by mass or more and 10% by mass or less. A method of manufacturing an abrasive tool, which is the method of manufacturing the abrasive tool of claim 1, and comprising: a step of mixing diamond particles, a metal powder constituting the metal substrate or a raw material thereof, and a metal hydride; a step of press-forming the obtained mixed powder; and a step of firing the press-formed molded article in a non-oxidizing atmosphere. A method of manufacturing a grinding tool, which is the method of manufacturing the grinding tool of claim 1, and comprising: a step of mixing diamond particles, a metal powder constituting the metal substrate or a raw material thereof, and a metal hydride; The mixed powder obtained in this step is subjected to a step of firing in a non-oxidizing atmosphere under pressure. A method for producing an abrasive comprising the steps of supplying a polishing liquid containing free abrasive grains to a surface of a hard and brittle material having a modified Mohs hardness of 8 or more, and grinding and grinding the abrasive tool according to claim 1 Further, as the free abrasive grains, abrasive grains having a Mohs hardness of 12 or more and other than diamond are used, and the free abrasive grain concentration is 2% by mass or more and 40% by mass or less is used as the polishing liquid.