JP2000015560A - Abrasive powder slurry and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide abrasive powder slurry capable of providing aluminum magnetic head flat in surface, and free of scratch (defect). SOLUTION: This invention is concerned with abrasive powder slurry for an aluminum magnetic head substrate formed out of aluminum oxide grains the average grain side of which is 0.05 to 1 μm, wherein the aluminum oxide grains contain 0.1 to 10 wt.% grains where the content of aluminum oxide grains each grain size of which is equal to or more than 5 μm, is less than 50 ppm, 64.9 to 99 wt.% water, 0.1 to 1 wt.% aluminum nitrate 0.1 to 3 wt.% nonionic surface active agent, 0.1 to 1 wt.% EDTA-2Na salt and 0.5 to 20 wt.% polyethylene glycol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abrasive slurry suitable for polishing an aluminum magnetic head substrate, an aluminum magnetic disk substrate, a silicon wafer, a silicon carbide substrate and the like, and a method for producing the slurry.

[0002]

2. Description of the Related Art For example, a magnetic disk is rotated at a high speed when used, a magnetic head is levitated, and writing, reading, and the like to and from a magnetic disk are performed through the magnetic head. In response to recent demands for high-density recording, the flying height of the magnetic head has been reduced to a lower level.
In order to realize this, it is required that the surface of the head and the disk be excellent in smoothness, and it is required that the surface roughness be 10 Å or less in the next generation.

Conventionally, in polishing an aluminum magnetic head substrate, the average particle size is 0.5 to 3 μm, preferably 0.5 to 3 μm.
When polishing the surface of a magnetic head substrate with a polishing cloth using an abrasive slurry in which free abrasive grains of 1.0 μm alumina oxide particles (α-alumina, polycrystalline alumina produced by a sol-gel method, etc.) are dispersed in water, An abrasive slurry is impregnated in a polishing cloth. However, the surface roughness of the obtained magnetic head substrate is 15 to 150 angstroms, and scratches are generated on the surface of the magnetic head substrate.

The scratches are caused by the presence of secondary agglomerated particles (2 to 10 particles agglomerated) or giant particles having a particle size of 5 μm or more, which are generated during the preparation of the alumina particles as free abrasive grains. It is said that the dispersibility is improved during the preparation of the slurry, and the surfactant of the dispersant is blended in the aqueous medium.
It has been proposed to loosen secondary particles into primary particles. However, even in the case of a polishing slurry in which alumina oxide of free abrasive grains is dispersed in an aqueous medium using a surfactant, it is impossible to eliminate the presence of secondary aggregated particles,
Even if the operation of passing the supernatant liquid of the slurry through a 20 μm sieve about 5 to 10 times is performed, alumina oxide particles having a particle diameter of 20 μm or more are present in the abrasive slurry of the filtrate, which causes scratches. The inventor has found that

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an abrasive slurry suitable for providing an aluminum magnetic head substrate having no scratch and a surface roughness of 10 Å or less. Further, the present invention provides a method for producing a polishing slurry for a magnetic disk and a semiconductor wafer.

[0006]

A first aspect of the present invention is an abrasive slurry in which abrasive grains having an average particle size of 0.05 to 1 μm are dispersed in an aqueous medium of 0.1 to 10% by weight. The content of abrasive grains having a particle size of 5 μm or more in the slurry is 50 pp
m or less. Claim 2 of the present invention relates to a) a) the average particle size is 0.
Abrasive grains having a particle size of from 0.5 to 1 μm, wherein the content of abrasive grains having a particle size of 5 μm or more is 50 ppm or less.
The present invention provides an abrasive slurry containing 1 wt%, 64.9 to 99 wt% of an aqueous medium, and c) 1 to 35 wt% of a polishing aid.

According to a third aspect of the present invention, the polishing aid is one of an inorganic salt, a dispersing aid, a surfactant, a chelating agent, a polishing oil, a rust preventive, an antifoaming agent and a pH adjuster. Or
An abrasive slurry according to claim 2, which is of two or more types. Claim 4 of the present invention relates to a) abrasive grains having an average particle size of 0.05 to 1 μm, wherein the particle size is 5 μm.
Abrasive grains having a content of the above abrasive grains of 50 ppm or less
1 to 10% by weight, b) 64.9 to 99% by weight of aqueous medium, c) 0.1 to 3% by weight of inorganic salt, d) Surfactant
The present invention provides an abrasive slurry containing 0.1 to 3% by weight, e) a chelating agent 0.1 to 1% by weight, and f) a polishing oil 0.5 to 20% by weight.

[0008] Claim 7 of the present invention relates to: a) the average particle diameter is 0.0
Aluminum oxide abrasive grains having a particle size of 5 to 1 μm.
The content of aluminum oxide abrasive grains of μm or more is 50 ppm
Abrasives 0.1 to 10% by weight, b) water 6
4.9-99% by weight, c) aluminum nitrate 0.1-
1% by weight, d) 0.1 to 3% by weight of nonionic surfactant, e) 0.1 to 1% by weight of EDTA-2Na salt, f)
Containing 0.5 to 20% by weight of polyethylene glycol;
An abrasive slurry for an aluminum magnetic head substrate is provided.

[0009] Claim 13 of the present invention is that the average particle size is 0.0
Ultrasonic waves having a frequency of 15 to 150 kilohertz (kHz) are applied to an abrasive slurry in which abrasive grains of 5 to 1 μm are dispersed in an aqueous medium of 0.1 to 10% by weight, with an intensity of 0.5 to 2 kilowatts per liter of the abrasive slurry. Irradiating the slurry with a slurry for 10 to 150 minutes, applying a supernatant liquid of the abrasive slurry to a sieve (filter) having an opening of 20 μm, and collecting the abrasive slurry passed through the sieve. The method for producing an abrasive slurry according to any one of claims 1 to 12, wherein the content of giant particles having a particle size of 5 µm or more is 50 ppm or less.

[0010] Claim 14 of the present invention is that the average particle size is 0.0
Abrasive slurry in which abrasive grains of 5 to 1 μm are dispersed in an aqueous medium of 0.1 to 10% by weight is subjected to ultrasonic waves of two or more kinds of frequencies 15 to 150 kilohertz (kHz) different in frequency by at least 15 kilohertz. 0.1 to 5 at an intensity of 0.5 to 2 kilowatts alternately per liter
After irradiating for a total of 10 to 150 minutes at intervals of milliseconds and applying vibration, the supernatant of the abrasive slurry was opened to an opening of 20 μm.
13. The slurry according to any one of claims 1 to 12, wherein the content of macroparticles having a particle size of 5 µm or more in the slurry is 50 ppm. The present invention provides the following method for producing an abrasive slurry.

[0011] Claim 15 of the present invention is that the average particle size is 0.0
Abrasive slurry in which 5-1 μm abrasive grains are dispersed in an aqueous medium of 0.1 to 10% by weight is applied with ultrasonic waves at a frequency of 15 to
Using ultrasonic waves of 25 kHz, ultrasonic waves of 30 to 60 kHz, and three types of ultrasonic waves of 80 to 120 kHz, vibrations of these frequencies are alternately applied with an intensity of 0.5 to 2 kilowatts per liter of the abrasive slurry. 0.1 ~
The polishing according to claim 14, characterized in that the slurry is irradiated with irradiation for a total of 10 to 150 minutes at intervals of 5 milliseconds, and the content of macroparticles having a particle size of 5 µm or more in the slurry according to claim 14 is 50 ppm or less. The present invention provides a method for producing an agent slurry.

[0012]

Since the abrasive slurry does not contain abrasive grains such as aluminum oxide particles having a particle size of 5 μm or more that cause scratches, scratches are not found on the polished head substrate. Further, the average grain size of the abrasive grains is 0.1 to 1 μm.
m, the flatness of the head is also improved.

Usually, ultrasonic vibration is applied to the slurry for the purpose of breaking secondary agglomeration of the dispersed abrasive grains in the slurry and returning them to primary particles. In the method of preparing a slurry according to the present invention, an ultrasonic vibration of a specific frequency is used. By applying a plurality of vibrations to the slurry for a specific time, the secondary aggregated particles which conventionally aggregate and generate giant particles during storage are positively settled below the slurry, and the sedimented secondary aggregated particles are The supernatant liquid of the abrasive slurry to which ultrasonic vibration was applied was collected by decantation, and further passed through a 20 μm sieve to remove giant particles from the slurry. The slurry no longer produces secondary agglomerated particles during storage. And a particle size of 5
The giant particles of μm or more are also 50 ppm or less in the slurry, and do not generate scratches on the head substrate. Further, by using two or more kinds of ultrasonic waves having different frequencies, the slurry temperature does not exceed 50 ° C., so that the abrasive slurry is not denatured.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Polishing object: The polishing slurry of the present invention is used for polishing a silicon wafer, an aluminum magnetic disk substrate, an aluminum magnetic head substrate, and a silicon carbide substrate. The material of the magnetic head substrate is aluminum / titanium carbonate alloy, and the material of the magnetic disk substrate is aluminum alloy plate, glass substrate, ceramic substrate, silicon carbide substrate, and nickel-phosphorus layer or chromium alloy layer on these substrates For example, a substrate provided with another texture layer is used.

Abrasive grains: As abrasive grains, aluminum oxide,
Examples include cerium oxide, single crystal diamond, polycrystalline diamond, silicon oxide, silicon carbide, chromium oxide, and glass powder. These abrasive grains have an average particle diameter of 0.1 to 1.
The particles have a particle size of 0 μm, preferably 0.3 to 0.5 μm, and the content of particles having a particle size of 5 μm or more is 50 ppm or less, preferably 10 ppm or less.

The polycrystalline diamond particles are obtained by shock-compressing a starting material comprising a metal catalyst (Co, Ni, Fe, etc.) and a graphite raw material powder using a shock wave generated by an explosive explosive or a collision with a high-speed flying object. Explosive synthesis method for producing diamond and grains (see Japanese Patent Publication No. 6-93995)
It is preferable to use those obtained by the method described above, wherein the amount of unreacted graphite (graphite) is small. These polycrystalline diamond particles are fine crystal solids that do not have a certain directionality are tightly bound. It can be obtained from the market under the trade name of MyPolex from DuPont, and from Sumitomo Coal Mining under the trade name of SCM Fine Diamond. This is subjected to wet classification to collect particles having a particle size of 0.05 to 0.5 μm. A narrow particle size distribution is preferred.

The content of abrasive grains in the abrasive slurry varies depending on the type and use of the abrasive grains.
%, Preferably 0.1 to 3% by weight. 0.05
If it is less than the weight percentage, a practical polishing rate cannot be obtained. If the content exceeds 10% by weight, no further improvement in the effect can be expected, and it is economically disadvantageous to use many of them.

Aqueous medium: As a dispersion medium, water alone or water as a main component (70 to 99% by weight in dispersion), and a water-soluble organic solvent such as alcohol or glycol as a subcomponent (1
-30% by weight) can be used. The water is preferably free of macroparticles as much as possible, as filtered through a 0.1 μm cartridge filter. Examples of the alcohol include methyl alcohol, ethyl alcohol, and isopropyl alcohol, and examples of the glycols include ethylene glycol, tetramethylene glycol, diethylene glycol, propylene glycol, and polyethylene glycol. The content of the aqueous dispersion medium in the abrasive slurry is 64.9 to 99% by weight, preferably 90 to 99% by weight. If it is less than 64.9% by weight, the viscosity of the slurry becomes high, and the supply of the abrasive slurry onto the substrate and the storage stability of the slurry are poor.

Polishing aid: Examples of the polishing aid include inorganic salts, dispersing aids, surfactants, chelating agents, polishing oils, rust inhibitors, defoamers, pH adjusters, fungicides, and the like. These are added for the purpose of improving the dispersion storage stability of the slurry and the polishing rate. Examples of the dispersing aid include sodium hexametaphosphate, oleic acid, and monobasic calcium phosphate. Examples of the pH adjuster include potassium hydroxide, sodium hydroxide, morpholine, and aqueous ammonia. Examples of the rust preventive include nitrogen-containing organic compounds such as alkanolamine / alkanolamine boric acid condensate, monoethanolamine, diethanolamine, triethanolamine, alkanolamine borate, and benzisothiazolines. Examples of the antifoaming agent include liquid paraffin, dimethyl silicone oil, monostearic acid, a mixture of di-glycerides, sorbitan monopalmitate, and the like. As a chelating agent, ethylenediaminetetraacetate (E
DTA-Na salt), citric acid, diethylene 8 amine pentaacetic acid, ethanol diglycinate, hydroxyethylene N-diamine triacetic acid, and the like.

Inorganic salt: Examples of the inorganic salt include aluminum or nickel nitrate, hydrochloride, sulfate, phosphate and thiosulfate.

Surfactants: Anionic surfactants are used as dispersants for dispersing free abrasive grains in an aqueous medium;
Cationic surfactant, nonionic surfactant, amphoteric surfactant, or combination of anionic surfactant and nonionic surfactant, combination of anionic surfactant and amphoteric surfactant Cationic surfactant The combination of a surfactant with a nonionic surfactant and the combination of a cationic surfactant with an amphoteric surfactant are exemplified. The type of the surfactant greatly contributes to the dispersibility of the abrasive grains and the polishing rate. The polishing rate is higher in the slurry using the anionic surfactant than in the slurry using the nonionic surfactant alone. Among the surfactants, sulfur (S), phosphorus (P), chlorine (C
l) The compound containing atoms has a higher polishing rate.

Anionic surfactant: Examples of the anionic surfactant include metal soaps such as sodium palmitate, sodium stearate, calcium oleate, aluminum stearate, and sodium / potassium palmitate; alkyl polyoxyethylene Ether carboxylate, alkylphenyl polyoxyethylene ether carboxylate, sulfated fatty acid alkyl ester, monoacylglycerol sulfate, secondary alkane sulfonate,
N-acyl-N-methyltauric acid, sodium dodecylbenzenesulfonate, alkyl ether phosphoric acid, alkyl polyoxyethylene phosphate, alkylphenyl polyoxyethylene phosphate, sodium naphthalene sulfonate, perfluoroalkyl phosphate, sulfonic acid Modified silicone oil and the like can be mentioned.

Among these, metal soaps, sulfone type anionic surfactants having a HLB of 5 or more, phosphate ester type anionic surfactants, fluorine-based or chlorine-based anionic surfactants, and combinations of two or more thereof Is preferred. The anionic surfactant is used in the slurry in an amount of 0.05 to
2% by weight is used. If it is less than 0.05% by weight, the dispersibility of the particles is poor, and the particles tend to settle. Even if it exceeds 2% by weight, it is not expected to further improve the effects of the dispersibility and the polishing rate, and it is preferable that the effect is small in terms of wastewater treatment.

Nonionic surfactant: Nonionic surfactants include polyoxyethylene alkyl ether,
Polyoxyethylene alkylphenyl ether, pronic nonionic surfactant (addition reaction product of ethylene oxide and propylene oxide), fatty acid polyoxyethylene ester, fatty acid polyoxyethylene sorbitan ester, polyoxyethylene castor oil, fatty acid sucrose ester, polyoxy Ethylene / oxypropylene alkyl ether;

Specific examples include polyethylene glycol dilaurate, tridecyl polyoxyethylene ether, nonylphenyl polyoxyethylene ether, polyethylene glycol monostearate, and the like. Preferably, compounds having an HLB of 10 or more are preferred. The nonionic surfactant is used in an amount of 0.1 to 3% by weight. However, polyoxyethylene alkyl ether,
Compounds that also have abrasive oil properties, such as polyoxyethylene alkyl phenyl ether and pronic nonionic surfactants (addition products of ethylene oxide and propylene oxide), are the total amount of abrasive oil and nonionic surfactant used. Up to 33% by weight of the slurry.

Amphoteric surfactant: Examples of the ampholytic surfactant include N-alkyl sulfobetaine-modified silicone oil,
N-alkyl nitrilotriacetic acid, N-alkyl dimethyl betaine, α-trimethyl ammonium fatty acid, N-alkyl β-aminopropionic acid, N-alkyl β-iminodipropionate, N-alkyloxymethyl-N, N
-Diethylbetaine, 2-alkylimidazoline derivatives, N-alkylsulfobetaines and the like.

When an anionic surfactant and a nonionic surfactant or amphoteric surfactant are used in combination, 1 part by weight of the anionic surfactant is added to 0.1 part by weight of the nonionic surfactant or the amphoteric surfactant. Used in a proportion of up to 5 parts by weight. The combined use improves the storage stability of the slurry. The content of the nonionic surfactant or amphoteric surfactant in the abrasive slurry is 0.05 to 3% by weight, preferably 0.1 to 0.5% by weight. If it is less than 0.05% by weight, there is no effect on improving the storage stability of the abrasive slurry.
If it exceeds 3% by weight, no further improvement in dispersibility can be expected. However, when a nonionic surfactant is used as a polishing oil component, it can be added up to 33% by weight as described above.

Polishing oil: Polishing oils include ethylene glycol, propylene glycol, polyethylene glycol, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, pronic nonionic surfactant (addition product of ethylene oxide and propylene oxide) ) And the like. The content of the polishing oil in the abrasive slurry is 0.5 to 20% by weight, preferably 1 to 10% by weight.

Polishing aid: Examples of the polishing aid include inorganic salts, dispersing aids, surfactants, chelating agents, polishing oils, rust inhibitors, defoamers, pH adjusters, fungicides, and the like. These are added for the purpose of improving the dispersion storage stability of the slurry and the polishing rate. Examples of the dispersing aid include sodium hexametaphosphate, oleic acid, and monobasic calcium phosphate. Examples of the pH adjuster include potassium hydroxide, sodium hydroxide, morpholine, and aqueous ammonia. Examples of the rust preventive include nitrogen-containing organic compounds such as alkanolamine / alkanolamine boric acid condensate, monoethanolamine, diethanolamine, triethanolamine, alkanolamine borate, and benzisothiazolines. Examples of the antifoaming agent include liquid paraffin, dimethyl silicone oil, monostearic acid, a mixture of di-glycerides, sorbitan monopalmitate, and the like.

Abrasive slurry: Abrasive slurry is prepared by mixing abrasive grains and an aqueous medium, and adding a surfactant, a dispersing agent, a fungicide, a rust inhibitor, a defoaming agent, a chelating agent, and an inorganic salt. And the like, and uniformly mixed with a homogenizer to form a slurry. Then, ultrasonic waves having two or more frequencies different from each other by at least 15 kHz are applied to the slurry 1.
1 alternately at intervals of 0.1 to 5 milliseconds per liter
After oscillating by irradiating for 0 to 150 minutes, the supernatant of the abrasive slurry is passed through a sieve (filter) having an opening of 20 μm, and the abrasive slurry passed through the sieve is collected. By doing so, the content of giant particles having a particle size of 5 μm or more in the slurry becomes 50 ppm or less. Further, the slurry is not denatured at the room temperature or at a temperature about 10 ° C. higher than the room temperature.

Preferably, the ultrasonic wave has a frequency of 15
Using ultrasonic waves of ６０25 kHz, ultrasonic waves of 30 to 60 kHz, and three types of ultrasonic waves of 80 to 120 kHz, vibrations of these frequencies are alternately generated for 0.1 to 5 milliseconds per liter of the abrasive slurry. At intervals of 10
It is preferable to irradiate the abrasive slurry for 150 minutes to give vibration. Irradiation of the ultrasonic frequency irradiates the slurry with a low frequency and a high frequency alternately to apply vibration to the slurry. The frequency may be two kinds, three kinds, or a mixture of more. For example, 24 kHz, 40 kHz, and 100 kHz. Vibrations are applied to the slurry at an intensity of 0.5 to 2 kilowatts at an intensity of 0.5 to 2 kilowatts, alternating between 0.1 and 5 milliseconds, at a total irradiation time of 10 to 150 minutes. The frequency and the irradiation time of the ultrasonic wave are appropriately confirmed by experiments in consideration of the average particle size and the particle size distribution of the abrasive grains.

The effect of vibrating the slurry by ultrasonic irradiation is to prevent secondary agglomeration of small particles of free abrasive grains and to induce secondary agglomeration of free abrasive grains having a large particle diameter to promote sedimentation as giant particles. is there. Because the abrasive particles in the slurry have a particle size distribution, vibrations at relatively low frequencies (15-50 kilohertz) have high energy, which causes agglomeration of large particle size (high surface area) abrasive particles. 5
It is presumed that high-frequency vibrations of 1 to 150 kHz have low energy but small waves, waves enter small gaps on the surface of the aluminum oxide particles, and wash out impurities that cause secondary aggregation, so that secondary aggregation is unlikely to occur. Is done. The viscosity of the thus obtained abrasive slurry at 23.5 ° C. (Rotary viscometer VISCOME manufactured by Rion Co., Ltd.)
TER VT-03 (trade name)) is 0.5 to 3
It is centipoise.

[0033]

The present invention will be described in more detail with reference to the following examples. Example 1 a) 2.5% by weight of aluminum oxide particles having an average particle size of 0.5 μm b) 93.5% by weight of water passed through a 0.1 μm cartridge filter c) 0.5% by weight of aluminum nitrate d) Chelating agent ( EDTA-2Na salt) 0.5% by weight e) Lauryl alcohol polyoxyethylene ether 1.0% by weight f) Polyethylene glycol (molecular weight 600) 2.0% by weight was mixed with a homogenizer to prepare an abrasive slurry.

The average particle size of the aluminum oxide particles in this slurry is 0.52 μm (particle size 0.05 to 1.8 μm).
In the case where this slurry was passed once through a 20 μm sieve with openings, abrasive grains of 5 μm or more (observed by an optical reflection microscope) were present at 800 ppm, and eight particles aggregated to 12 μm Or 5-8μ
What grew into giant particles of about m
About 10 were observed.

One liter of the slurry was irradiated with ultrasonic waves of 24 kilohertz at an intensity of 1.2 kilowatts for 5 milliseconds, then with ultrasonic waves of 40 kilohertz for 5 milliseconds, and with ultrasonic waves of 100 kilohertz for 5 milliseconds. The step of irradiating the three kinds of ultrasonic waves having different frequencies for 5 milliseconds at a time so that the total time becomes 30 minutes, the slurry is allowed to stand still for 5 minutes, The liter was passed once through a 20 μm sieve, and the filtrate was collected and used as an abrasive slurry.

The average particle size of the aluminum oxide particles of this abrasive slurry is 0.48 μm, and the particle size is 0.2 to 1.3.
Most of the particles had a width of μm, and particles having a particle size of 5 μm or more were 20 ppm or less. Optical reflection microscope (400
In the field of view (approximately 2700 square millimeters), the number of particles exceeding 5 μm was 0 or 1. The abrasive slurry thus obtained is impregnated into a polishing cloth wound on the surface of a rotating roll, and this roll is then exposed to the surface of a cylindrical aluminum-potassium titanate alloy (surface roughness Ra 26
Angstrom), and the rotation of the roll and the rotation of the aluminum-potassium titanate alloy were performed under the following conditions to polish the alloy (head). Head rotation speed 800 r.pm Polishing cloth pressing force 2.0 kg Roll rotation speed 1300 r.pm Polishing time 8 seconds The surface roughness of the polished alloy is measured with a surface roughness meter (Komatsu Seisakusho E
T30HK: trade name), measuring length 0.25mm,
When measured at a speed of 20 μm / sec with a stylus 0.5 μmR, load 3 mg, 8 angstrom (R
a). Also, the surface of the alloy was measured with a surface defect analyzer using laser light, and the width was 1-3 μm and the length was 20 μm.
When the number of the following scratches was measured, micro scratches were not detected.

Comparative Example 1 An alloy (head) was polished in the same manner as in Example 1, except that the abrasive slurry not subjected to ultrasonic treatment was used as the abrasive slurry. The flatness of the head was 12 Å, and there were three scratches of 20 μm or more.

Example 2 a) Polycrystalline diamond particles having an average particle size of 0.18 μm (particle size of 0.05 to 0.28 μm) (obtained by an explosion method) 0.1% by weight b) 0.1 μm cartridge Filtered water 94.4% by weight b ') Pluoran 3.6% by weight c) Naphthalenesulfonic acid sodium salt 0.3% by weight d) Sodium potassium palmitate 0.1% by weight e) Alkanolamine / alkanolamine borane Acid condensate 1.0% by weight f) One liter of an abrasive slurry (0.5 ppm by weight of particles having an average particle size of 5 μm or more) containing 0.5% by weight of an ethylene oxide adduct of dodecyl alcohol was irradiated with 5 millimeters of 24 kHz ultrasonic waves. Second, followed by a 40 kHz ultrasonic wave for 5 milliseconds and a 100 kHz ultrasonic wave for 5 milliseconds at an intensity of 1.2 kilowatts. And, following, different ultrasound wavelengths of the three 5 ms Total time irradiating increments 30
After irradiating the slurry, the slurry was allowed to stand for 5 minutes, and then the filtrate, which had passed 0.95 liter above the slurry and passed through a 20 μm sieve once, was collected, and used as an abrasive slurry. .

The average particle size of the polycrystalline diamond particles of this abrasive slurry is 0.18 μm,
Most of the particles were within a width of 0.28 μm, and particles having a particle size of 5 μm or more were 10 ppm or less. The number of particles having a particle diameter of more than 5 μm was 0 or 1 within the visual field range of the optical reflection microscope. Using this slurry, the slurry is infiltrated into a polishing cloth wound on the surface of a rotating roll, and the roll is subjected to nickel-phosphorus electroless plating on the surface of a disk-shaped aluminum alloy substrate (surface roughness Ra 18 Å). And the substrate was polished by rotating the roll and rotating the substrate under the following conditions. Substrate rotation speed 800 r.pm Polishing cloth pressing force 2.0 kg Roll rotation speed 1000 r.pm Polishing time 10 seconds The surface roughness of the polished substrate is measured using a surface roughness meter (E Komatsu Ltd.)
T30HK: trade name), measuring length 0.25mm,
When measured at a speed of 20 μm / sec with a stylus 0.5 μmR, load 3 mg, 8 angstrom (R
a).

When the surface of the substrate was measured with a surface defect analyzer using laser light, and the number of scratches having a width of 1 to 3 μm and a length of 20 μm or less was measured, micro scratches were not detected. The polishing amount was 3.0 mg.

Comparative Example 2 An aluminum disk substrate was polished in the same manner as in Example 2 except that an abrasive slurry not subjected to ultrasonic treatment was used as the abrasive slurry. The flatness of the obtained aluminum disk substrate is 13 Å,
Five micro scratches were found.

[0042]

The abrasive slurry of the present invention provides an aluminum magnetic head and an aluminum magnetic disk having a flat surface and no scratches.

Claims (16)

[Claims] An abrasive having an average particle diameter of 0.05 to 1 μm is used in an amount of 0.1 to 1 μm.
An abrasive slurry dispersed in an aqueous medium of 1 to 10% by weight, wherein the content of abrasive grains having a particle size of 5 μm or more in the abrasive slurry is 50 ppm or less. 2. a) Abrasive grains having an average grain size of 0.05 to 1 μm, and a content of abrasive grains having a grain size of 5 μm or more is 50 ppm.
An abrasive slurry containing 0.1 to 10% by weight of the following abrasive grains, b) 64.9 to 99% by weight of an aqueous medium, and c) 1 to 35% by weight of a polishing aid. 3. A polishing aid comprising an inorganic salt, a dispersing aid, a surfactant, a chelating agent, a polishing oil, a rust inhibitor, a defoaming agent and a pH.
The polishing slurry according to claim 2, wherein the polishing slurry is one or more selected from conditioning agents. 4. An abrasive having an average particle size of 0.05 to 1 μm, wherein the content of the abrasive having a particle size of 5 μm or more is 50 ppm.
0.1 to 10% by weight of abrasive grains, b) 64.9 to 99% by weight of aqueous medium, c) 0.1 to 3% by weight of inorganic salt, d) 0.1 to 3% by weight of surfactant, e) chelating agent 0.1-1% by weight, f) polishing oil 0.5-20% by weight
Abrasive slurry containing. 5. The method according to claim 1, wherein the abrasive grains are particles selected from aluminum oxide, cerium oxide, single crystal diamond, polycrystalline diamond, silicon oxide, silicon carbide, chromium oxide and glass powder. 2,
3. The abrasive slurry according to any one of items 3 and 4. 6. A nonionic surfactant, wherein the surfactant is:
The abrasive slurry according to any one of claims 3, 4, and 5, wherein the abrasive slurry is selected from an anionic surfactant composed of a compound containing an atom selected from S, P, and Cl. 7. A) Aluminum oxide abrasive having an average particle diameter of 0.05 to 1 μm, wherein the content of the aluminum oxide abrasive having a particle diameter of 5 μm or more is 50 ppm or less.
0.1-10% by weight, b) 64.9-99% by weight of water, c) 0.1-1% by weight of aluminum nitrate, d) 0.1-3% by weight of nonionic surfactant, e) EDTA
An abrasive slurry for an aluminum magnetic head substrate, comprising 0.1 to 1% by weight of -2Na salt and 0.5 to 20% by weight of polyethylene glycol. 8. The abrasive slurry according to claim 3, wherein the inorganic salt is selected from nitrates, hydrochlorides, sulfates, phosphates, and thiosulfates of aluminum or nickel. 9. A nonionic surfactant comprising a polyoxyethylene alkyl ether, a polyoxyethylene alkyl phenyl ether, a pluonic nonionic surfactant (an addition reaction product of ethylene oxide and propylene oxide), a fatty acid polyoxyethylene ester, 8. The abrasive slurry according to claim 3, which is selected from fatty acid polyoxyethylene sorbitan ester, polyoxyethylene castor oil, fatty acid sucrose ester and polyoxyethylene oxypropylene alkyl ether. . 10. An anionic surfactant comprising a metal soap such as sodium palmitate, sodium stearate, calcium oleate, aluminum stearate, sodium / potassium palmitate; an alkyl polyoxyethylene ether carboxylate; Alkyl phenyl polyoxyethylene ether carboxylate, sulfated fatty acid alkyl ester, monoacylglycerol sulfate,
Secondary alkane sulfonate, N-acyl-N-methyltauric acid, sodium dodecylbenzenesulfonate, alkyl ether phosphoric acid, alkyl polyoxyethylene phosphate, alkylphenyl polyoxyethylene phosphate, sodium naphthalene sulfonate, perfluoro The abrasive slurry according to claim 6, which is selected from an alkyl phosphate and a sulfonic acid-modified silicone oil. 11. The polishing slurry according to claim 3, wherein the polishing oil is selected from ethylene glycol, tetramethylene glycol, diethylene glycol, propylene glycol, and polyethylene glycol. 12. An abrasive slurry comprising: a silicon wafer;
An aluminum magnetic disk substrate, an aluminum magnetic head substrate, and used for polishing a silicon carbide substrate.
12. The abrasive slurry according to any one of 11 above. 13. An abrasive having an average particle size of 0.05 to 1 μm.
The abrasive slurry dispersed in an aqueous medium of 0.1 to 10% by weight is irradiated with ultrasonic waves having a frequency of 15 to 150 kilohertz (kHz) at an intensity of 0.5 to 2 kilowatts per liter of the abrasive slurry for 10 to 150 minutes. After applying vibration,
The polishing slurry according to any one of claims 1 to 12, wherein the supernatant liquid of the polishing slurry is passed through a sieve (filter) having an opening of 20 µm, and the polishing slurry passed through the sieve is collected. how to. 14. An abrasive having an average particle size of 0.05 to 1 μm.
Abrasive slurry dispersed in an aqueous medium of 0.1 to 10% by weight is polished with ultrasonic waves having frequencies of 15 to 150 kHz (kHz) having frequencies different from each other by at least 15 kHz with an intensity of 0.5 to 2 kilowatts. Agent slurry
After irradiating by irradiating for 10 to 150 minutes at intervals of 0.1 to 5 milliseconds alternately per liter, the supernatant of the abrasive slurry is sieved through a sieve (filter) having an opening of 20 μm. The method for producing an abrasive slurry according to any one of claims 1 to 12, wherein the passed abrasive slurry is collected. 15. An abrasive having an average particle size of 0.05 to 1 μm.
Ultrasonic waves having a frequency of 15 to 25 kHz, ultrasonic waves having a frequency of 30 to 60 kHz, and ultrasonic waves having a frequency of 15 to 25 kHz are added to an abrasive slurry dispersed in an aqueous medium of 0.1 to 10% by weight.
Using three kinds of ultrasonic waves of 120 kHz, vibrations of these frequencies are alternately set to 0.1 Hz per liter of the abrasive slurry.
The method for producing an abrasive slurry according to claim 14, wherein the slurry is irradiated by irradiating with an intensity of 5 to 2 kilowatts at intervals of 0.1 to 5 milliseconds for a total of 10 to 150 minutes. 16. The polishing slurry according to claim 13, wherein the opening is inclined by a decantation method using a 20 μm sieve, and the supernatant of the abrasive slurry to be filtered is 80 to 95% by weight of the whole slurry. A method for producing an abrasive slurry according to any one of claims 15 to 15.