JPH10204417A - Processing aid composition, abrasive composition, surface processing and production of substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition as a processing aid, capable of polishing a surface at a high speed without leaving defects on the surface by incorporating an organic compound having a specific molecular structure. SOLUTION: This composition comprises at least (A) a processing aid and (B) water, wherein the component A is a water-soluble or water-dispersible organic compound having a weight-average molecular weight of 500 to 1,000,000 and poly (>=3) nuclear condensed ring. It is preferable that the composition contains 0.01 to 30wt.% of the component A, the compound having 0.1 to 4 of at least one of sulfonic group, carboxyl group, phosphoric group and the like on the average per 500 units of the molecular weight, e.g. condensed sodium tannate sulfonate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing aid composition, an abrasive composition and a surface processing method useful for processing the surface of a substrate, especially a substrate for a magnetic disk, a lens, a ceramic material or the like.

[0002]

2. Description of the Related Art NiP
Surface polishing of members made of a metal material such as plated Al substrate or cemented carbide, or a brittle material such as a glass material, a carbon material, and a ceramic material is generally performed using submicron to tens of micron-sized diamond or alumina. It is performed using an abrasive composition in which abrasive grains such as SiC are dispersed in water (Japanese Patent Laid-Open No. 54-893).
No. 89, Japanese Unexamined Patent Publication No. Hei. Also, Japanese Patent Application Laid-Open No. 60-44576 proposes to include a diallyl terephthalate copolymer in order to improve the heat resistance of the abrasive composition.

However, conventional surface polishing using an abrasive composition has been insufficient to meet the recent demand for high-quality surfaces and low cost. For example, in the conventional abrasive composition, because the dispersibility of the abrasive grains in the abrasive composition and the dispersion removal and prevention of re-adhesion of the processing dust (fine powder generated by grinding and polishing) are insufficient. There were surface defects such as pits and scratches on the surface of the object to be polished, and scratches easily entered the surface of the object to be polished under high pressure conditions, so that the polishing rate could not be increased and there was a limit to cost reduction. .

Accordingly, an object of the present invention is to provide a processing aid composition capable of processing a surface at a high speed without causing surface defects on the surface of a workpiece, particularly the surface of a workpiece made of a brittle material, and a polishing agent. An object of the present invention is to provide a material composition, a surface processing method, and a method for manufacturing a substrate.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above object can be achieved by using an organic compound having a specific molecular structure as a processing aid.

The present invention has been made on the basis of the above findings. In a processing aid composition containing at least a processing aid and water, the processing aid has a weight average molecular weight of 50.
The above-mentioned object has been achieved by providing a processing aid composition comprising a water-soluble or water-dispersible organic compound having 0 to 1,000,000 and a fused ring of three or more nuclei. It is.

Further, the present invention comprises the above-mentioned processing aid composition and an abrasive, wherein the content of the abrasive is 0.01 to 30.
% By weight.

Further, the present invention provides a surface processing method, wherein the processing aid composition is brought into contact with the surface of a workpiece, and at the same time, a grindstone or an abrasive is pressed against the surface of the workpiece. Is provided.

Further, the present invention provides a method for producing a substrate having a polishing step using an abrasive composition containing at least an abrasive, a processing aid and water, wherein the abrasive composition is used. Another object of the present invention is to provide a method of manufacturing a substrate characterized by the following.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the processing aid composition of the present invention will be described. As described above, the processing aid composition of the present invention contains the processing aid and water as essential components.

The processing aid used in the processing aid composition of the present invention has a weight average molecular weight of 500 to 10
A water-soluble or water-dispersible organic compound having a molecular weight of 10,000 and having a fused ring of three or more nuclei is used.

The weight average molecular weight of the organic compound is 500
If less than the above, the dispersion stability will be insufficient, and if it exceeds 1,000,000, the water solubility or water dispersibility will decrease, and the effect will be insufficient. The weight average molecular weight is 1,000 to 5
It is preferably 100,000, more preferably 1,000 to 100,000. The weight average molecular weight is a value measured by gel permeation chromatography (in terms of polystyrene).

The organic compound has a condensed ring in which three or more aromatic rings are condensed (that is, a condensed ring having three or more nuclei). Since the organic compound has such a structure, decomposition stability is increased, and the heat resistance and pressure resistance of the processing aid composition of the present invention are improved. Time is reduced. Further, due to its decomposition stability, it can be used even under severe pH conditions as described later, so that the processing time is further reduced. Further, since the rust prevention property is good, the durability of the processing machine is also improved.

Specific examples of the above organic compound include relatively low molecular weight condensed ring compounds such as sodium anthracene sulfonate and sodium phenanthroline sulfonate; nitrohumic acid, sodium sulfonate humic acid, tannic acid, and condensed tannin. High-molecular-weight condensed ring compounds such as sodium sulfonate of acid, sodium sulfonate of formalin condensate of anthracene, and sodium sulfonate of formalin condensate of phenanthroline are exemplified. These organic compounds can be used alone or in combination of two or more.
Of these, use of sodium sulfonic acid, which is a formalin condensate of nitrohumic acid and anthracene, is particularly preferable since decomposition stability and pressure resistance are improved.

The organic compound has one or more trinuclear or higher condensed rings per 500 molecular weight units (particularly, 1 to 3 units).
2) is preferable from the viewpoint of decomposition stability.

The above organic compound preferably contains a polar group from the viewpoint of solubility in water and adsorption to abrasives and processing chips. Particularly, as the polar group, a sulfonic acid group, a carboxyl group, a phosphoric acid group, a phosphorous acid group, a phosphonic acid group,
Phosphonous acid group, phosphinic acid group, phosphinous acid group,
It preferably contains one or more tertiary amino groups, quaternary ammonium bases, or nitro groups, and particularly preferably contains a sulfonic acid group, a carboxyl group, or a tertiary amino group. In order to introduce these polar groups into the organic compound, for example, the introduction of a sulfonic acid group may be carried out by a sulfonation method using fuming sulfuric acid as a sulfonating agent, or by the introduction of a tertiary amino group or a quaternary ammonium base. A well-known method such as an amination method using a Mannich reaction can be used.

The organic compound preferably contains 0.1 to 4 of these polar groups on average per 500 units of molecular weight, more preferably 0.1 to 3 of these polar groups,
It is more preferable to contain 0.3 to 2 pieces. If the content of the polar group is less than 0.1, the solubility in water may be deteriorated, or the adsorptivity to abrasives and processing chips may be reduced, and the polishing rate may be significantly reduced. When the ratio exceeds the above range, the conditions for synthesizing the organic compound become severe, which may increase the cost in industrial production.

The processing aid comprising the organic compound is preferably present in the processing aid composition of the present invention in an amount of from 0.01 to 30.
% By weight, more preferably 0.05 to 10% by weight.
Contained. If the content of the processing aid is within the above range, the viscosity of the processing aid composition of the present invention is appropriately maintained,
Moreover, the effect of improving the processing speed is sufficiently exhibited.

Water, which is the other essential component in the processing aid composition of the present invention, is used as a medium, and its content in the composition is preferably from 40 to 99.
9% by weight, more preferably 70 to 99.9% by weight.
And more preferably 85 to 99.5% by weight.
When the water content is within the above range, the workpiece can be subjected to surface processing with high production efficiency.

In the processing aid composition of the present invention, other components can be added as necessary in addition to the above-mentioned essential components. Examples of the additive include a metal salt of a monomeric acid compound (hereinafter, the metal salt of the monomeric acid compound is referred to as a “monomer auxiliary”). By using the above-mentioned processing aid and the monomer-type auxiliary in combination, the processing speed is further improved by the cooperative effect of the two.

The metal salt of a monomer type acid compound (monomer type auxiliary) means a metal salt of a non-polymerizable (ie, monomer) acid compound. The acid compound is not particularly limited as long as it has some oxidizing action. Specific examples of the acid compound include nitric acid, sulfuric acid, sulfurous acid, persulfuric acid, hydrochloric acid, perchloric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, pyrophosphoric acid, carbonic acid, lactic acid, oxalic acid, benzoic acid, citric acid, and Malonic acid and organic acids having these as a functional group are exemplified. Examples of the metal of the metal salt of the acid compound include aluminum, magnesium, nickel and iron, and aluminum and magnesium are preferably used. The above monomer type auxiliaries can be used alone or in combination of two or more. In particular, as the monomer-type auxiliary agent, it is preferable to use one or more selected from the group consisting of metal salts of nitric acid, metal salts of sulfuric acid, metal salts of oxalic acid, metal salts of lactic acid and metal salts of benzoic acid, In particular, the use of aluminum nitrate, aluminum oxalate, aluminum lactate, nickel benzoate, or the like is preferable because the effect of improving the polishing rate is further enhanced.

The above-mentioned monomer type auxiliary is contained in the processing auxiliary composition of the present invention preferably in an amount of 0.001 to 20% by weight, more preferably 0.05 to 10% by weight.
When the content of the monomer-type auxiliary agent is within the above range, the processing speed is sufficiently improved, and the processing speed is saturated even when the content exceeds 20% by weight.

Further, in the processing aid composition of the present invention, in addition to the above-mentioned monomer-type assistant, various surfactants, alkaline substances, various defoamers, various foaming agents, various thickeners, various Additives such as dispersants, various rust preventives, chelating agents, and organic solvents can also be used. In addition, a known inorganic salt such as aluminum nitrate can be used as a polishing accelerator.
These additives are each preferably added to the processing aid composition of the present invention in an amount of 0.001 to 10% by weight.

The pH of the processing aid composition of the present invention is not particularly limited, and may be appropriately selected depending on the material of the workpiece. In particular, as described above, since the processing aid has high decomposition stability, severe pH conditions can be used to increase the processing rate. For example, in the case of a carbon substrate, the pH is preferably 1 to 6, particularly preferably 3 to 5.
When the pH is within the above range, the surface of the carbon substrate is easily oxidized, so that the processing speed is increased. In order to adjust the pH of the processing aid composition of the present invention to the above range, for example,
A predetermined amount of the processing aid and, if necessary, the monomer-type auxiliary may be added.

The processing aid composition of the present invention is used in combination with various processing tools (for example, a single-sided and double-sided polishing device, a surface grinding device, an aspherical surface grinding device, an end surface processing device, and a cutting device) to form a workpiece. , Such as polishing, grinding, and cutting (cutting). In particular, the processing aid composition of the present invention is suitably used for surface processing (polishing, grinding, and the like) of a workpiece, and is particularly used in combination with a fixed grindstone to grind the surface of a workpiece, for example, a grinding allowance. Of about 10 to 1000 μm, and the center line average roughness Ra after grinding is suitably used for rough grinding of about 0.01 to 2 μm. In this specification, "polishing" refers to smoothing using loose abrasive grains, and "grinding" refers to smoothing using a tool such as a fixed grindstone.

Examples of the material of the workpiece to be processed using the processing aid composition of the present invention include NiP-plated aluminum, glass, carbon such as glassy carbon, silicon, and other ceramic materials. No. Of these, when processing is performed on a workpiece made of a brittle material such as glass or glassy carbon using the processing aid composition of the present invention, compared to the case where a conventional processing aid is used. This is preferable because the processing can be performed quickly while suppressing the generation of cracks. There is no particular limitation on the shape of these workpieces. For example, a shape having a flat portion such as a disk shape, a plate shape, a slab shape, a prism shape, or a shape having a curved surface portion such as a lens is used for the processing of the present invention. It is an object of processing using the auxiliary composition.

Next, the abrasive composition of the present invention will be described. In addition, about the point which does not specifically detail about the abrasive composition of this invention, the description which mentioned in detail about the said processing aid composition is suitably applied.

The abrasive composition of the present invention comprises the above-mentioned processing aid composition and an abrasive, and the content of the abrasive is 0.01 to 30% by weight in the abrasive composition. Polishing of the surface of the workpiece, for example, a polishing allowance of 50 to 1000 μ
m, the center line average roughness Ra after polishing is 0.01 to 2
Rough polishing (lapping) or polishing allowance of about μm is 0.
Ra after polishing is about 0.002 to about 50 μm.
It is preferably used for finish polishing (polishing) of about 0.002 μm (2 to 20 °).

As the above-mentioned abrasive, abrasive grains generally used for polishing can be used. Specific examples of the abrasive include alumina-based particles, SiC particles,
Examples include diamond particles, ZrO ₂ particles, MgO particles, and colloidal silica particles. Among these abrasives, it is preferable to use alumina-based particles or SiC particles because the polishing rate is high. Particularly, it is preferable to use intermediate alumina particles as the alumina-based particles because the surface roughness of the workpiece can be extremely reduced. In this specification,
Intermediate alumina particles are a general term for alumina particles other than α-alumina particles, and specifically, γ-alumina particles, δ
-Alumina particles, θ-alumina particles, η-alumina particles, amorphous alumina particles and the like. These abrasives can be used alone or in combination of two or more.

The average particle size of the primary particles of the abrasive is 0.0
It is preferably from 01 to 3 μm. When the average particle diameter of the primary particles is larger than 3 μm, for example, when the workpiece is polished,
In particular, when polishing a workpiece made of a hard material such as glassy carbon, it may be difficult to reduce the surface roughness of the workpiece, and if it is less than 0.001 μm, the polishing rate is low. Therefore, it is preferable to be within the above range. The more preferable average particle size of the primary particles of the abrasive is 0.005 to 1 μm, and the more preferable average particle size is 0.01 to 0.5 μm. Further, abrasives having large and small particle sizes can be used in combination. The average particle size of the primary particles of the abrasive was determined by adding a dispersant to 0.1 g of the abrasive, then applying ultrasonic waves to disperse the abrasive, and further drying the resultant to obtain an SEM. Observed and determined by image analysis. If the average particle size is 2 μm or more, a Coulter counter [model MULTI
SIZER-II, manufactured by Coulter, Inc.].

The above abrasive is used in the abrasive composition of the present invention in a so-called slurry state using water as a medium. The content of the abrasive in the abrasive composition of the present invention can be variously selected depending on the viscosity of the abrasive composition of the present invention and the required quality of a workpiece, and the like, but as a general range. The content is 0.01 to 30% by weight as described above.
And preferably 0.05 to 15% by weight. When the content of the abrasive is within the above range, low surface roughness is achieved with high production efficiency.

In addition, the above-mentioned abrasive is used in relation to the amount of the above-mentioned processing aid (ie, the above-mentioned organic compound) in terms of the concentration ratio of the abrasive and the processing aid [density of abrasive (weight %) / Concentration of processing aid (% by weight)] is preferably 0.01 to 25. If the concentration ratio is less than 0.01, the abrasive slides (that is, the polishing removal efficiency decreases).
However, if it exceeds 25, the effect of blending the processing aid may not be sufficiently exhibited, so that it is preferably within the above range. The above concentration ratio is
0.02 to 10, more preferably 0.02 to 10.
5 is more preferable.

The abrasive material has a Knoop hardness (JIS
Z-2251) is preferably from 700 to 9000. If the Knoop hardness is less than 700, a sufficient polishing rate cannot be obtained, and the productivity may be reduced.
If it exceeds 0, the thickness of the processing damage layer (that is, the layer of micro cracks and chipping) generated on the surface of the object to be polished may be large and the surface quality may be deteriorated. The Knoop hardness is 1000
More preferably from 5000 to 5000, and from 1500 to 30
More preferably, it is 00.

The abrasive has a specific gravity of 2 to 5 in view of dispersibility, supply to a polishing apparatus, and recovery and reuse.
Is preferable, and it is more preferable that it is 2-4.

A particularly preferred abrasive is Knoop
99% by weight or more with a hardness of 1500 to 3000
99.9% by weight or more of α-Al_TwoO_ThreeParticles or γ-
Al _TwoO_ThreeParticles. Such abrasives are made of high-purity aluminum
Crystal growth method using a sodium salt (such as the Bernoulli method)
Crushing that is commonly used
Alumina produced by the method is large in terms of shape and purity
Very different. The reason for using such an abrasive is not always obvious.
Not sure, but synergistic effect with addition of processing aid
Is preferable. In addition, the purity of the above abrasive
Dissolve 1-3 g in an aqueous acid or alkali solution and add
Quantitative analysis of aluminum ions by the plasma emission spectroscopy
It is required by doing.

According to the present invention, the above-mentioned processing aid composition is brought into contact with the surface of a workpiece, and simultaneously, a grindstone or abrasive grains (free abrasive grains) are pressed against the surface of the workpiece. Is provided. A preferred embodiment of such a surface processing method will be described with reference to FIGS. 1 and 2, taking as an example a surface grinding when a glassy carbon substrate, which is one of carbon materials, is used as a substrate for a magnetic recording medium. Here, FIG. 1 is a schematic front view showing a double-side processing machine used in a rough grinding step of a glassy carbon substrate, and FIG. 2 is a view taken along line XX in FIG.

A double-sided processing machine 1 shown in FIG.
An upper stool 3 disposed above the lower stool 2;
And a surface plate supporting portion 4 for supporting the upper surface plate 3 in contact with the surface plate.

As shown in FIG. 1, the upper platen 3 has a bracket 12 attached to the tip of the output rod 11a of the air cylinder 11.
It is rotatably mounted via. The upper platen 3 can be moved up and down by the air cylinder 11, and when the upper platen 3 descends, it engages with the groove of the rotor 13 which rotates in the direction of arrow D shown in FIG. Has been made. Further, on the lower surface of the upper platen 3, a particulate processing material (abrasive grains) is dispersed by a binder agent.
A fixed grindstone (not shown) that is held is provided. The upper platen 3 is fixedly fastened to the platen support 4 by bolts (not shown), and is provided rotatable together with the platen support 4.

As shown in FIG. 2, the lower stool 2 is provided on the base 5 so as to be rotatable in the direction of arrow A. On the upper surface thereof, a fixed grindstone arranged on the upper stool 3 is provided. A fixed grindstone 6 of the same type as that described above is provided. Further, the lower platen 2 has a planetary gear-shaped carrier 9 which meshes with a sun gear 7 rotating in the direction of the arrow B at the center and an internal gear 8 rotating in the direction of the arrow C on the outer periphery to revolve while rotating. There are four aircraft. Then, the glass-like carbon substrate 1 as a workpiece is placed in each of eight holes provided in each carrier 9.
0 is set.

Between the upper platen 3 and the lower platen 2,
The processing aid composition of the present invention is supplied in a predetermined amount by a slurry supply pipe (not shown).
By lowering the upper platen 3 by the air cylinder 11, the glassy carbon substrate 10, which moves integrally with the carrier 9, is roughly ground by being sandwiched between the lower platen 2 and the upper platen 3. Is performed.

The fixed grindstones arranged on the upper surface plate 3 and the lower surface plate 2 are diamond, CBN (Cubic Bron Nit
ride), particles (abrasive grains) such as alumina, SiC, ZrO ₂ , MgO or colloidal silica are dispersed and held in a binder agent. Among these particles, it is preferable to use diamond, alumina or SiC because the processing speed is further improved. In the present embodiment, diamond particles are used as a processing material. The average particle size of these particles depends on the type of processing (polishing, grinding, cutting), the degree of processing, the material of the workpiece, and the like.
Generally, the average particle size of the primary particles is preferably from 0.005 to 150 μm, and more preferably from 0.005 to 75 μm. Further, as the binder agent, for example, a metal bond agent made of a simple metal such as Fe (eg, cast iron), Cu, or Ni, or an alloy containing one or more of these can be used.

The glassy carbon substrate used for the above-mentioned rough grinding is obtained by hardening a carbonaceous resinous material (phenol resin or the like) between a pair of glass plates, punching it into a predetermined shape, and firing. The center line average roughness Ra is about 0.02 to 10 μm before rough grinding. Then, the glassy carbon substrate is roughly ground under the conditions described later, so that the center line average roughness Ra is about 0.5 mm.
1-2 μm.

The conditions for rough grinding of a glassy carbon substrate using the double-sided processing machine are generally as follows. That is, the processing pressure is preferably from 10 to 20.
00 g / cm ² , more preferably 30 to 1500
g / cm ² . Processing time is preferably 2-120
Minutes, more preferably 2 to 30 minutes. The processing temperature is preferably between room temperature and 50 ° C. The average particle size of the diamond particles in the fixed grindstones respectively disposed on the upper and lower platens of the double-sided processing machine is preferably 150 to 0.0002 μm.
And more preferably 75 to 0.0005 μm. The lower platen rotation speed of the double-sided processing machine depends on the size of the processing machine. The flow rate of the processing aid composition of the present invention depends on the processing machine size.
The speed is preferably 5 to 300 cc / min, and more preferably 10 to 150 cc / min, if it is a 9B type double-side processing machine manufactured by PEED FAM.

Next, with regard to a preferred embodiment of a method of manufacturing a substrate having a polishing step using the abrasive composition of the present invention, a rough polishing of a glassy carbon substrate for a magnetic recording medium roughly ground by the above-described method will be described. (Lapping) and subsequent finish polishing (polishing) will be described as an example. In addition, as for the points that are not particularly described in detail regarding the rough polishing (lapping) and the finish polishing (polishing) in the present embodiment, the description described in detail regarding the rough grinding using the processing aid composition described above is appropriately applied. In this specification, the term “substrate” is not limited to a shape having a flat surface such as a disk, a plate, a slab, and a prism, but also includes a shape having a curved surface such as a lens. .

The rough polishing (lapping) and the finish polishing (polishing) of the present embodiment can be performed by using a double-side processing machine used for the above-described rough grinding. When performing rough polishing (lapping), use a metal plate made of cast iron or the like that does not contain the abrasive grains, for the upper and lower platens of the double-sided processing machine,
A predetermined amount of the abrasive composition of the present invention is supplied through a hole formed in the upper platen. The average particle size of the primary particles of the abrasive in the abrasive composition is preferably 3 to 100 μm,
The concentration is preferably 1 to 30% by weight, particularly preferably 2 to 20% by weight. On the other hand, when performing final polishing (polishing), a resin polishing pad such as a urethane foam pad is attached to the upper and lower platens of the double-sided processing machine, and the abrasive composition of the present invention is supplied from a slurry supply pipe. The average particle size of the primary particles of the abrasive in the abrasive composition is smaller than that in the case of rough polishing (lapping), and is preferably 0.001 to 3 μm. The concentration of the abrasive is lower than that in the case of rough polishing (lapping), and is preferably 0.01 to 30% by weight, particularly preferably 0.05 to 15% by weight.

Finish polishing (polishing) of this embodiment
Are generally as follows. That is,
Processing pressure is preferably 10~2000gf / cm ^2, more preferably from 30~1500gf / cm ^2. The processing time is preferably from 2 to 120 minutes, more preferably from 2 to 30 minutes. The processing temperature is preferably between room temperature and 50 ° C. Hardness of the polishing pad mounted on the upper and lower platens of the double-sided processing machine [JIS (JIS)
K-6301)] is preferably 40 to 100
And more preferably 60 to 100. The lower platen rotation speed of the double-sided processing machine depends on the processing machine size. For example, in the case of a 9B type double-sided processing machine manufactured by SPEED FAM, it is preferably 10 to 100 rpm, more preferably 10 to 60 rpm. The supply flow rate of the abrasive composition of the present invention depends on the processing machine size.
If it is a 9B type double-sided processing machine manufactured by ED FAM, it is preferably 5 to 300 cc / min, more preferably 10 cc / min.
１５０150 cc / min.

By subjecting the roughly polished (lapping) glassy carbon substrate to finish polishing (polishing) under the above conditions, its center line average roughness Ra is about 4 to
20Å.

The polishing step using the above abrasive composition is particularly effective in the polishing step, but can be similarly applied to the lapping step.

The surface processing method and the substrate manufacturing method of the present invention are not limited to the above embodiment, and for example, another processing machine may be used in place of the above-described double-side processing machine. Further, as the workpiece, carbon other than glassy carbon, aluminum (NiP-plated aluminum), glass, silicon, or the like can also be used. The object of processing is
The present invention is not limited to a substrate for a magnetic recording medium, and can be similarly applied to a silicon wafer for a semiconductor, an optical mirror, a half mirror, an optical prism, and the like.

[0050]

The following examples illustrate the effectiveness of the present invention. However, the scope of the present invention is not limited to such an embodiment.

Examples 1 to 15 and Comparative Examples 1 to 9
Was mixed and stirred with water at the concentrations shown in Table 1 to obtain an abrasive composition. The types of processing auxiliaries and monomer type auxiliaries used are as shown in Tables 3 and 4. A substrate (see Table 1) of each material having a diameter of 1.8 inches having a center line average roughness Ra of 0.1 μm by rough polishing was used by using the abrasive composition.
Finish polishing with a double-sided processing machine. At this time, the double-sided processing machine was used under the following conditions.

<Setting conditions of double-sided processing machine> Double-sided processing machine used: 9B type double-sided processing machine manufactured by SPEED FAM Processing pressure: 150 gf / cm ² Processing time: 120 minutes Hardness of polishing pad: 90 [JIS A (JIS K- 6
301)] Lower platen rotation speed: 40 rpm Abrasive composition flow rate: 50 cc / min

In Examples 1 to 4, the working pressure of the double-sided working machine was set to 100 g / cm ^2, and Examples 10 and 11 were used.
In Comparative Examples 1 and 2, the processing pressure of the double-sided processing machine was set to 250 gf / cm ² which was higher than usual.

Each substrate in the examples and comparative examples was polished for 60 minutes (only the NiP / Al substrate was polished for 10 minutes), the removal amount was measured, and the relative polishing rate was determined based on the comparative example. Table 2 shows the results. The center line average roughness Ra (粗) of the surface of each substrate after polishing was measured, and the degree of scratch generation was evaluated according to the following criteria. Table 2 shows the results.

[Center line average roughness Ra] Measured using a tally step manufactured by Rank Taylor Hobson. [Scratch] Using optical microscope observation (differential interference microscope), the surface of each substrate was measured at six points at 60 ° intervals at a magnification of × 50. The scratch depth is ZYGO (ZYGO)
Was measured by The evaluation criteria are as follows. S: 0 scratches with a depth of more than 500 mm per field A: Less than 0.5 scratches with a depth of more than 500 mm / 1 field of view B: 0.5 or more scratches with a depth of more than 500 mm on average / 1 visual field C: Average of one or more scratches exceeding 500mm in depth /
One field of view

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

[Table 3]

[0059]

[Table 4]

As is clear from the results shown in Table 2, the abrasive compositions containing the above processing aids (Examples 1 to 15)
When the substrate is polished using, the polishing rate is improved and the surface roughness is reduced as compared with the case where the substrate is polished using the abrasive composition containing no processing aid (Comparative Examples 1 to 9). It can be seen that the temperature is lower and the generation of scratches can be suppressed. In particular, Example 10 in which polishing was performed at a processing pressure higher than usual
11 shows that the polishing rate was extremely high.

[0061]

According to the present invention, a processing aid composition, an abrasive composition, which can process a surface at a high speed without causing surface defects such as pits and scratches on the surface of a workpiece,
A surface processing method and a method for manufacturing a substrate are provided. The present invention is particularly suitable for surface processing of a workpiece made of a brittle material.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a main part showing a double-side processing machine preferably used in a surface processing method and a substrate manufacturing method of the present invention.

FIG. 2 is a view taken along line XX in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Double-sided processing machine 2 Lower surface plate 3 Upper surface plate 4 Substrate support part 5 Base 6 Fixed whetstone 9 Carrier 10 Substrate

Claims (18)

[Claims] 1. A processing aid composition comprising at least a processing aid and water, wherein the processing aid has a weight average molecular weight of 500 to 1,000,000 and a condensed ring of three or more nuclei. A processing aid composition comprising a water-soluble or water-dispersible organic compound. 2. The method according to claim 1, wherein said processing aid is present in an amount of 0.01 to 30% by weight.
The processing aid composition according to claim 1, further comprising: 3. The method according to claim 1, wherein the organic compound has an average of 0.1 to 4 sulfonic acid groups, carboxyl groups, phosphoric acid groups, phosphorous acid groups, phosphonic acid groups, phosphonous acid groups, and phosphinic acid per 500 units of molecular weight. The processing aid composition according to claim 1 or 2, which contains one or more of a group, a phosphinous acid group, a tertiary amino group, a quaternary ammonium base, or a nitro group. 4. The processing aid composition according to claim 1, further comprising at least one metal salt of a monomeric acid compound. 5. The method according to claim 1, wherein the metal salt of the monomeric acid compound is 0.1 to 0.1%.
The processing aid composition according to claim 4, which contains 001 to 20% by weight. 6. The metal salt of the monomeric acid compound is selected from the group consisting of a metal salt of nitric acid, a metal salt of sulfuric acid, a metal salt of oxalic acid, a metal salt of lactic acid, and a metal salt of benzoic acid. The processing aid composition according to claim 4 or 5, which is the above. 7. The processing aid composition according to claim 1, which is used in combination with a fixed grindstone. 8. A polishing composition comprising the processing aid composition according to claim 1 and an abrasive, wherein the content of the abrasive is 0.
An abrasive composition characterized in that the amount is from 0.01 to 30% by weight. 9. The concentration ratio of the abrasive to the processing aid [concentration of abrasive (% by weight) / concentration of processing aid (% by weight)] is 0.01 to 25. 9. The abrasive composition according to 8. 10. A Knoop hardness (JIS Z) of the abrasive material.
The abrasive composition according to claim 8 or 9, wherein (-2251) is from 700 to 9000. 11. The abrasive composition according to claim 8, wherein the specific gravity of the abrasive is 2 to 5. 12. The abrasive composition according to claim 8, wherein the primary particles of the abrasive have an average particle size of 0.001 to 3 μm. 13. The polishing material according to claim 1, wherein the Knoop hardness is 1500 to 1500.
The abrasive composition according to any one of claims 8 to 12, comprising α-Al ₂ O ₃ or γ-Al ₂ O ₃ particles having a purity of at least 99% by weight and having a weight of 3000. 14. A carbon substrate, NiP plated Al
The polishing composition according to any one of claims 8 to 13, which is used for polishing a substrate, a silicon substrate, or a glass substrate. 15. Contacting the processing aid composition according to any one of claims 1 to 6 with a surface of a workpiece, and simultaneously pressing a grindstone or abrasive grains against the surface of the workpiece. Characteristic surface processing method. 16. A method for producing a substrate having a polishing step using an abrasive composition containing at least an abrasive, a processing aid, and water, wherein the abrasive composition is used as the abrasive composition.
15. A method for producing a substrate, comprising using the abrasive composition according to any one of items 14 to 14. 17. The method according to claim 17, wherein the substrate is a magnetic recording medium substrate.
A method for manufacturing a substrate according to claim 16. 18. The method according to claim 16, wherein the polishing step is a polishing step.