JPH1128669A - Super abrasive grain metal bond grinding wheel for precise cutting and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a super abrasive grain metal bond grinding wheel with an excellent cutting property, and its manufacturing method. SOLUTION: This super abrasive grain metal bond grinding wheel for precise cutting consists of a sintered body made by dispersing and including a ceramic whiskers in a super abrasive grain including metal, or a lamination layer formed by holding a sintered body made by dispersing and including a ceramic whiskers in a super abrasive grain including metal, between super abrasive grain including metal sintered body plates, and the ceramic whiskers consist of one or more than two sorts of silicon carbide, potassim titanate, aluminum borate, alumina, and silicon nitride, and preferably the sintered body scattering and including the ceramic whiskers is obtained by making a slurry including super abrasive grains, a metal powder, ceramic whiskers, a water soluble resin binder, and a surface active agent and a plasticizer when necessary, and water in the remaining part, forming the slurry into a plate form by a doctor blade method, drying the obtained plate form compact, and sintering after it is punched in a specific form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin blade grindstone used for precision cutting and grooving of electronic material parts and a method for producing the same.

[0002]

2. Description of the Related Art For cutting or grooving materials such as silicon wafers, magnets, quartz, etc., a method of manufacturing a precision cutting whetstone made of a metal sintered body containing diamond or cBN as superabrasive grains is used. Conventionally, a powder rolling method or a mold forming / hot pressing (HP) method has been used.

[0003]

However, in the conventional powder rolling method or the mold forming / HP method, the rigidity of the precision cutting grindstone obtained is small, and there are disadvantages such as bending, increase in cutting resistance, and chipping. The frequency of occurrence of the problem increases, which is a problem.

[0004] In the powder rolling method, since the formed material contains superabrasive grains, the rolling roll is susceptible to abrasion, the roll life is short, and the powder to be used is reduced. There is also a problem that the body must be excellent in compression moldability, and there is a limit to the types of metals that can be used. Also,
In the mold molding / HP method, there is a problem that a difference in density and a variation in thickness are easily generated due to unevenness in powder filling, and the performance is not stable.

According to the present invention, there is provided a method of manufacturing a precision cutting whetstone and a main whetstone in which a whisker is provided with orientation in a matrix to enhance the rigidity of the whetstone, thereby improving cutting performance, and to provide an inexpensive manufacturing method. The purpose is to provide.

[0006]

In order to achieve the above object, a superabrasive metal bond grindstone for precision cutting of the present invention (hereinafter simply referred to as a grindstone of the present invention) and a method for producing the same are described as follows. A grindstone consisting of a sintered body in which ceramics whiskers are oriented and dispersed in a metal, and (2) sintering in which ceramics whiskers are oriented and dispersed in a superabrasive containing metal between super-abrasive-containing metal sintered plates. (3) a super-abrasive metal bond grindstone for precision cutting, characterized in that a plurality of grindstone bodies having a ceramic whisker oriented in a single direction are laminated in a plurality of directions. . (4) The ceramic whisker is one or two of silicon carbide, potassium titanate, aluminum boride and alumina.
A whetstone according to any one of (1) to (3), which is a seed or more, (5) a sintered body containing the ceramic whisker oriented and dispersed therein comprises superabrasive grains, a metal powder, a ceramic whisker, A slurry containing a water-soluble resin binder, a surfactant and water is prepared, and this slurry is
(1) to (4), wherein the obtained plate-shaped molded body is dried, punched into a predetermined shape, and then fired; (6) The method for producing a grinding wheel according to (5), wherein the slurry further contains a plasticizer.

In the present invention, a superabrasive, a metal powder as a binder component and, if necessary, a ceramic whisker are mixed in a slurry form with an organic binder or the like as a liquid medium. By suspending and dispersing the super-abrasive grains and the metal powder in the liquid medium in this manner, the aggregation of the super-abrasive grains and the like can be prevented and the density unevenness can be suppressed. Further, by sufficiently kneading the slurry, the density can be improved. It is possible to suppress unevenness and thickness variation. In particular, since the unevenness of the superabrasive grain distribution is kept low, it is possible to keep the cutting resistance, bending, chipping and cuff width of the obtained grindstone small,
In addition, the strength of the whisker can be further increased by suppressing whisker breakage and orienting the whisker.

Further, the raw material in the form of a slurry can be easily formed to a predetermined thickness by a doctor blade method, and does not require expensive equipment such as a rolling roll, so that it is economical. It is also advantageous. Furthermore, as the metal powder that can be used in the present invention, all metals that can be powdered and sintered can be used, so that various types can be selected and various types of metals can be mixed. The degree of freedom of the composition is very high, and from this, it is possible to produce a grindstone having characteristics different from those of a conventionally known precision cutting grindstone. Also, when a thin plate is formed by the doctor blade method, whiskers are oriented in the plate forming direction, and a very strong grinding wheel body can be obtained in that direction. By laminating the grindstone bodies combining these directions, it is possible to increase rigidity in all directions.

[0009]

Embodiments of the present invention will be described below. First, metal powder (Cu, Sn, etc.), superabrasives (diamond, cBN, etc.), ceramic whisker
(Silicon carbide, potassium titanate, aluminum borate, alumina, silicon nitride, etc.) and an organic binder (water-soluble binder, surfactant, plasticizer, etc.)
The metal powder, the superabrasive grains and, if necessary, the ceramic whisker are mixed in a slurry state with an organic binder, and this is stretched into a plate shape by, for example, a doctor blade method to form the plate. Next, the plate-shaped formed body was dried to prepare a pre-formed body, and the pre-formed body was Φ110 mm
Then, the grinding wheel body is punched out, and then the grinding wheel body is debindered at 400 to 550 ° C. in a nitrogen or hydrogen atmosphere or in a vacuum.
A disc-shaped sintered body is manufactured by pressurizing and firing at 600 to 800 ° C. in a hydrogen atmosphere or vacuum. This is punched out with a press, Φ100mm × Φ40m
An mx 0.50 mmt cutting wheel of the present invention is manufactured.

As the doctor blade method, it is more preferable to use a two-blade blade 60A, 60B as shown in FIG. This is because large air bubbles B are removed from the gap between the two blades 60A and 60B, and the second blade 60A is removed.
Large bubbles do not enter the plate-like molded product 1A extruded from the gap between B and the carrier sheet 10, and the thickness of the molded product 1A is made uniform regardless of the level of the liquid level of the raw material slurry S. Because you can. In this case, the carrier sheet 10
The gap G1 between the cutting edge of the first blade 60A on the downstream side and the carrier sheet is more preferably larger than the gap G2 between the cutting edge of the second blade 60B and the carrier sheet. . Also, the first blade 60A and the second blade 60
It is more preferable that the gap D of B is, for example, about 5 to 20 mm. Further, the carrier blade of the second blade 60B is used.
The gap G2 with the gate 10 is suitably in the range of 0.1 to 2 mm.

As the superabrasive grains, for example, diamond grains,
Although cBN particles are used, the present invention is not limited to these. In addition, the abrasive grain size is not particularly limited, and is appropriately selected depending on the purpose of use of the grindstone to be obtained.
Those having a size of about μm are used. The blending amount of the superabrasive grains in the slurry is preferably in the range of 1 to 10% (% by weight, the same applies hereinafter), particularly in the range of 5 to 8%.

The type of the metal powder is not particularly limited as long as it can be sintered at a temperature lower than the melting point of the superabrasive grains.
All metals and alloys to be sintered such as tin, lead, copper, nickel, iron, cobalt, chromium, etc. can be used. The average particle diameter of the metal powder is 500 μm or less, particularly 0.5 μm.
The range is preferably from 100 to 100 μm. Average particle size 0.5μm
If the particle size is smaller than the above, dispersion may not be sufficiently performed, and the slurry may react with water and ignite. On the other hand, if the average particle size is larger than 500 μm, the strength of the finished grindstone may be too weak. The compounding amount of the metal powder in the slurry is preferably in the range of 40 to 90%, particularly preferably 60 to 80%.

The ceramic whiskers include silicon carbide, potassium titanate, aluminum borate, alumina, silicon nitride and the like.
μm, diameter: 0.1 to 10 μm, desirably, length: 1
0 to 20 μm, diameter: 0.5 to 5 μm. If this length exceeds 50 μm, it is difficult to disperse in metal, while if this value is less than 5 μm, it does not contribute to strengthening. When the diameter is larger than 10 μm, the surface roughness of the processed surface is deteriorated,
If it is 0.1 μm or less, it does not contribute to strengthening. The mixing amount of the ceramic whisker in the slurry is 0.5 to 10
% By weight, especially in the range of 1 to 5% by weight.

The water-soluble resin binder has a function of maintaining the shape of the porous molded body when the slurry is dried. It also functions as a slurry viscosity modifier. Examples of the water-soluble resin binder include methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, carboxymethylcellulose ammonium, ethylcellulose, polyvinyl alcohol and the like. The compounding amount of the water-soluble resin binder is 0.5 to 20.
% By weight, especially in the range of 2 to 10% by weight. 0.5
If the amount is less than 10% by weight, the strength of the dried molded article is low, which may hinder handling.
If the amount is more than the weight percentage, the viscosity may be too high and molding may be difficult.

Surfactants act to improve the dispersion stability of superabrasives, metal powders and ceramic whiskers in a liquid medium, alkylbenzene sulfonates, α-olefin sulfonates, alkyl sulfates, alkyl ethers, and the like. Examples thereof include anionic surfactants such as sulfates and alkane sulfonates, and nonionic surfactants such as polyethylene glycol derivatives and polyhydric alcohol derivatives. The compounding amount of the surfactant is 0.
The range is preferably from 0.5 to 5% by weight, particularly preferably from 0.5 to 3% by weight. If the amount is less than 0.05% by weight, the dispersion stability of the superabrasives, metal powder and ceramic whisker cannot be improved, while if it is more than 5%, no further effect can be seen. There are cases.

[0016] In addition to the above components, a plasticizer can be added to the raw material slurry of the present invention. The plasticizer is for imparting plasticity to the molded product, and is a polyhydric alcohol such as ethylene glycol, polyethylene glycol, and glycerin; oils and fats such as sardine oil, rapeseed oil, and olive oil; Ethers such as ter, diethyl phthalate,
Esters such as di-n-butyl phthalate, diethylhexyl phthalate, dioctyl phthalate, sorbitan monooleate, sorbitan trioleate, sorbitan palmitate and sorbitan stearate can be exemplified. . The amount of the plasticizer is 0.1 to 15% by weight, especially 2%.
The range is preferably from 10 to 10% by weight. If the amount is less than 0.1% by weight, the plasticization may be insufficient, while if it is more than 15% by weight, the strength of the molded article may be insufficient.

The preform is cut into a predetermined shape by a punch press and sent to the next firing step. Alternatively, the preform may be cut at predetermined lengths with a cutter or the like, and the cut product may be punched in a state in which a plurality of the whisker orientations are combined and a plurality of the cut products are stacked.

The firing step is preferably a two-step process. The first step is called degreasing, and is a step of volatilizing an organic binder and the like, and the second step is a step of sintering a metal powder. Also, these steps can be continuous. The degreasing step is performed, for example, under an inert gas atmosphere such as a nitrogen gas atmosphere, a reducing gas atmosphere such as a hydrogen gas atmosphere, or a vacuum atmosphere.
It can be fired at a temperature of about ° C for a time of 30 to 120 minutes.

The sintering process depends on the type of metal to be manufactured.
Depending on the ammonia decomposition gas atmosphere, such as hydrogen gas
In a reducing atmosphere, in a vacuum, or in an inert gas atmosphere such as nitrogen gas.
Under ambient atmosphere, for example, at a temperature of about
It can be baked for 60 minutes. Furthermore, this sintering process
Under pressure conditions, for example, 100-1000 kg / cm ^Two 
Can also be performed. Obtained when pressure sintering
To maintain the porous structure of the grindstone, for example, hot isostatic
The pressure pressing (HIP) method is preferred.

In such a degreasing / sintering step, in order to prevent deformation (warping) of the preformed body or to further facilitate pressurization, for example, a heat treatment of carbon graphite, ceramics or the like is performed. It is preferable that the preform be sandwiched between substrates that are made of a material that is stable in nature and that is unlikely to cause metal fusion, and then fired.

The superabrasive sinter thus obtained is
Finally, the product is punched into a ring-shaped plate by a stamping press or the like to a precise size based on a conventional method, and the inner peripheral portion of this ring plate is joined to the outer peripheral portion of a copper circular substrate by brazing or the like. It is said. Note that the present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

Also, a green sheet manufactured by a conventional molding method or a doctor blade method similar to the present invention using the same super-abrasive grains and metal powder as the present invention, It is also possible to sandwich a green sheet in which ceramic whiskers are dispersed and contained in the abrasive-containing metal as the material of the present invention described above and sinter it under pressure to form a laminated grindstone. The laminated whetstone formed in this way has improved sharpness, especially at the time of cutting.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be specifically described.
I do. Example 1 30 g of copper powder having an average particle size of 5 μm, average particle size
6 g of tin powder of 10 μm, 20/30 μm manufactured by DE BEERS
4 g of diamond abrasive grains of particle size, fiber diameter 0.6 μm, length
0.4 g of 15 μm potassium titanate whiskers and
Kneading 15g of organic binder manufactured by the following composition
It was kneaded using a machine. Organic binder component ・ Methylcellulose 3% by weight ・ Alkylbenzenesulfonate 0.5% by weight ・ Water remainder
, It is stretched into a thin plate. The size of the obtained plate is approximately
It was 120 mm x 200 mm x 0.8 mmt.
The plate is dried to form a green compact, and the green component is formed.
A disk-shaped green molded body with an outer diameter of 110 mm
It was punched by a press. This is φ120m made of carbon
hydrogen atmosphere at 450 ° C for 30 minutes
The binder was removed in the air. Then, as it is
Pressurized (200kg / cm ^Two ) And 650 ° C for 3
Sinter in a nitrogen atmosphere for 0 minutes, press punch, φ1
00mm × φ40mm × 0.50mmt thin blade of the present invention
A stone 1 (hereinafter, referred to as a grinding stone 1 of the present invention) was manufactured. Obtained
The variation in the thickness of the grindstone was ± 5 μm.

(Conventional example) Copper powder 30 having an average particle size of 5 μm
g, tin powder having an average particle size of 10 μm, 6 g, manufactured by DE BEERS
4 g of 0/30 μm diamond abrasive grains
Mix for 30 minutes with a type mixer. Next, the mixture was filled into a press mold, and φ10 at a pressure of 5 ton / cm ^2.
It was formed into a thin disk of 0 mm × φ40 mm × 0.55 mmt. This disc is sandwiched between carbon discs having a diameter of 120 mm, and the disc is pressed (200 kg / cm ² ).
Sintering for 100 minutes in a nitrogen atmosphere, φ100mm × φ40m
mx 0.50 mmt thin blade whetstone 1 (hereinafter referred to as
Conventionally referred to as a whetstone).

Comparative Example 1 Copper powder 30 having an average particle size of 5 μm
g, tin powder having an average particle size of 10 μm, 6 g, manufactured by DE BEERS
4 g of diamond abrasive grains having a particle diameter of 0/30 μm, and a fiber diameter of 0.
6 μm, 15 μm long potassium titanate whisker
0.4 g was mixed with a shaker type mixer for 30 minutes. Next, this mixture was powder-rolled to about 120 mm.
It was formed into a plate of × 250 mm × 0.55 mmt. Punched from this plate with a press, outer diameter φ100mm, inner diameter φ4
A donut-shaped disc of 0 mm was obtained. This disc is sandwiched between carbon discs of φ120 mm and pressurized (200 kg / c
m ² ), and sintered at 650 ° C. for 30 minutes in a nitrogen atmosphere to produce a comparative thin blade whetstone 1 (hereinafter referred to as comparative whetstone 1) of φ100 mm × φ40 mm × 0.50 mmt by a conventional powder rolling method. . An attempt was made to disperse the whiskers by the rolling method. However, as a result of observation of the structure, a large number of separated whiskers were observed, and the dispersing condition was also uneven.

Comparative Example 2 Copper powder 30 having an average particle size of 5 μm
g, tin powder having an average particle size of 10 μm, 6 g, manufactured by DE BEERS
4 g of 0/30 μm diameter diamond abrasive grains, fiber diameter 1 μ
m, 20 μm long aluminum borate whiskers.
6 g was mixed in a shaker type mixer for 30 minutes.
Next, the mixture was filled into a press mold, and 5 ton / cm
^It was formed into a thin disk of about 100 mm × 40 mm × 0.6 mmt under the pressure of ² . This disk is made of carbon 120 m
and pressurized (200 kg / cm ² )
And sintered in a nitrogen atmosphere at 700 ° C. for 30 minutes.
A comparative thin blade whetstone 2 (hereinafter referred to as a comparative whetstone 2) was manufactured by a compression method using a conventional press mold of 00 mm × φ40 mm × 0.50 mmt. Whisker dispersion was attempted by the mold / HP method. However, as a result of observation of the structure, the orientation of the whiskers was not remarkably observed, and the dispersion state was uneven.

Example 2 Copper powder 30 having an average particle size of 5 μm
g, tin powder having an average particle size of 10 μm, 6 g, manufactured by DE BEERS
4 g of diamond abrasive grains having a particle diameter of 0/30 μm, and a fiber diameter of 0.
Aluminum borate whisker of 6 μm and length of 15 μm
0.6 g and 15 g of an organic binder produced according to the following composition were kneaded using a kneader. Organic binder component ・ Methylcellulose 3% by weight ・ Alkylsulfate 0.5% by weight ・ Ethylene glycol (plasticizer) 1% by weight ・ Water remainder The kneaded product obtained as described above is doctor-blended. -It is stretched into a thin plate by a metal method. The size of the obtained plate was approximately 120 mm × 800 mm × 0.20 mmt.
The plate was dried to form a green compact, and four disc-shaped green compacts having an outer diameter of 110 mm were punched out from the green compact by a press. The four compacts were rotated by 45 degrees and laminated, and this was made of carbon φ120 mm.
And a binder removal treatment was performed at 450 ° C. for 30 minutes in a hydrogen atmosphere. Next, under this condition, pressure was applied (200 kg / cm ² ), and calcination was performed at 650 ° C. for 1 hour in a nitrogen atmosphere to obtain a laminated sintered body. This is stamped out by pressing, φ100mm × φ40mm × 0.50
mmt of the thin blade 2 of the present invention (hereinafter, referred to as the grindstone 2 of the present invention). The thickness variation of the obtained whetstone is ± 1
It was 0 μm.

Example 3 Copper powder 30 having an average particle size of 5 μm
g, tin powder having an average particle size of 10 μm, 6 g, manufactured by DE BEERS
4 g of diamond abrasive grains having a particle diameter of 0/30 μm, and a fiber diameter of 0.
Aluminum borate whisker of 6 μm and length of 15 μm
1.0 g and 15 g of an organic binder produced according to the following composition were kneaded using a kneader. Organic binder component ・ Methylcellulose 3% by weight ・ Alkylsulfate 0.5% by weight ・ Ethylene glycol (plasticizer) 1% by weight ・ Water remainder The kneaded product obtained as described above is doctor-blended. The sheet was stretched into a thin plate by a C-d method to obtain two plates. The size of the two obtained plates is approximately 120 mm × 200 mm
× 0.16 mmt. Each of the plates was dried to form a green compact, and two disc-shaped green compacts having an outer diameter of 110 mm were punched out from the green compact by a press. Next, 30 g of copper powder having an average particle size of 5 μm,
6 g of tin powder having an average particle size of 10 μm, 20
4 g of diamond abrasive grains having a particle size of 30 μm and 15 g of an organic binder produced with the following composition were kneaded using a kneader. Organic binder component ・ Methylcellulose 3% by weight ・ Alkyl sulfate ester 0.5% by weight ・ Ethylene glycol (plasticizer) 1% by weight ・ Water remainder The kneaded material obtained as described above is doctored. It is stretched into a thin plate by the blade method. The size of the obtained plate is
It was approximately 120 mm × 200 mm × 0.16 mmt. The plate is dried to form a green compact, and the green
A disk-shaped green compact having an outer diameter of 110 mm was punched out of the green compact by pressing. In the same manner, three green compacts that had been stamped out were produced. The two green compacts containing the aluminum borate whiskers are alternately sandwiched between the three green compacts in such a manner that the whisker orientation is rotated by 60 degrees. The sandwiching body is sandwiched by a disc made of carbon and having a diameter of 120 mm.
The binder was removed in a nitrogen atmosphere at 0 ° C. for 30 minutes. Next, pressurization (200 kg /
cm ² ), sintered at 650 ° C. for 30 minutes in a nitrogen atmosphere, press-punched, φ100 mm × φ40 mm × 0.
A thin blade whetstone 3 of the present invention (hereinafter, referred to as whetstone 3 of the present invention) having a thickness of 50 mmt was manufactured (see FIG. 1). The variation in the thickness of the obtained grindstone was ± 6 μm. In addition, all of the above three types of the grindstones of the present invention showed good dispersion of abrasive grains.

(Cutting Test) Using the above-described grindstones 1 to 3 of the present invention, conventional grindstones, and comparative grindstones 1 and 2, a cutting test of a single crystal silicon wafer was performed using a slicing machine manufactured by Fujikoshi. Table 1 shows the cutting conditions, and Table 2 shows the cutting test results. Single crystal silicon wafer is 100mm x 100mm x 1
mm-sized ones were used.

[0030]

[Table 1]

[0031]

[Table 2]

The cutting resistance was measured by a dynamic strain meter. A single crystal silicon wafer was stuck on a dynamic strain meter, and the maximum stress at the time of cutting was measured. In addition, the maximum bending amount,
As shown in FIG. 3, the maximum deviation of the blade locus and the cutting width were measured by a tool microscope after cutting as shown in FIG.

In addition, the maximum chipping amount was measured for the size of the chipped portion at the cut portion after cutting with a tool microscope.

[0034]

As is clear from Table 2, the grinding wheels 1 to 5 of the present invention can be used.
Sample No. 3 is smaller in cutting resistance, maximum bending amount, maximum chipping amount and cuff width than conventional grinding stones and comparative grinding stones 1 and 2, and is excellent in cutting performance. This is because, in particular, the use of the doctor blade method easily reduces unevenness in the density and thickness of the sintered body constituting the grindstone and improves the rigidity of the blade. With the use of, the degree of freedom of the metal composition is increased, the uniform dispersion of the ceramic whiskers is realized, the performance is sufficiently exhibited, and a long-life grinding wheel can be provided at low cost. Was. In addition, a sharper whetstone can be provided by the laminated whetstone.

[Brief description of the drawings]

FIG. 1 is a schematic view of an example of a laminated grindstone of the present invention.

FIG. 2 is a sectional view showing a main part of a two-blade doctor blade;

FIG. 3 is a view showing a maximum bending amount and a cuff width measured in the embodiment of the present invention.

Claims (6)

[Claims] 1. A ceramic whisker for a metal containing superabrasive grains.
A super-abrasive metal bond whetstone for precision cutting, characterized by being made of a sintered body containing oriented and dispersed therein. 2. A precision cutting method comprising a laminated body in which a sintered body in which a ceramic whisker is oriented and dispersed and contained in a superabrasive grain-containing metal is sandwiched between superabrasive grain-containing metal sintered body plates. Super-abrasive metal bond whetstone. 3. A super-abrasive metal bond grinding wheel for precision cutting, characterized in that said ceramic whiskers are formed by laminating a plurality of grinding bodies in a single direction in a plurality of directions. 4. The method according to claim 1, wherein said ceramic whisker is one or more of silicon carbide, potassium titanate, aluminum borate, alumina and silicon nitride. Super abrasive metal bond whetstone for precision cutting. 5. A sinter containing oriented and dispersed ceramic whiskers is prepared as a slurry containing superabrasive grains, metal powder, ceramic whiskers, a water-soluble resin binder, a surfactant and water. The slurry is formed into a plate by a doctor blade method, and the obtained plate is dried, punched into a predetermined shape, and fired. 3. The method for producing a superabrasive metal bond grindstone for precision cutting according to any one of 3. 6. The method for producing a superabrasive metal bond grindstone for precision cutting according to claim 5, wherein said slurry further contains a plasticizer.