JPH054171A - Resin-bond grinding wheel for precision working - Google Patents

Abstract

PURPOSE:To provide a grinding wheel enabling hard material or soft material to have a mirror surface of excellent surface roughness, said hard material including various ceramics sintered materials, glass, single crystal, CBN sintered material, diamond sintered material, and diamond cladding material, said soft material including a magnetic tape. CONSTITUTION:A precision-working resin bond grinding wheel containing at least 30% by volume of inorganic salt abrasive grains. By this, the surface roughness of a worked material is improved approximately 5 to 242 times as greatly as that obtainable with a grinding wheel containing conventional abrasive grains. When comparison is made in terms of the surface roughness of the same worked material, improvement is made approximately 38 to 151 times.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor wafers and substrates, magnetic head substrates, laser reflecting mirrors, optical parts, precision machine parts, precision measuring instrument parts, electronic parts, and other ceramics and glass used in various industries. The present invention relates to a resin-bonded grindstone for precision machining which is most suitable for mirror-finishing a hard material or a soft-working material represented by a single crystal.

[0002]

2. Description of the Related Art Conventionally, among grinding processes or grinding processes, for finishing processes such as lapping and polishing for the purpose of mirror finishing, it is mainly harder than the material to be processed and mainly hard such as diamond or cubic boron nitride. Abrasive grains or a whetstone containing them are used.

On the other hand, a finish processing method in which a so-called mechanochemical, which is a chemical reaction induced by a mechanical action with a material to be processed, is used by using abrasive grains softer than the material to be processed or a grindstone containing the same. Is proposed.

A typical example of this mechanochemical processing method is "Mechanoche" by Vora et al.
medical Polishing of Silico
nNitride ”[J. Am. Cer. Soc, 65
(9) C-140 (1982)], Karaki et al., "Mechanism for promoting machining speed in mechanochemical polishing of Si single crystal" [Precision Machinery, 46, 3 (1980) 53-59],
Ochiai et al. "Mechanochemical polishing of ferrite materials"
[Journal of Precision Engineering, 54, 3 (1988) 146-15
1] and JP-A-64-64766.

[0005]

[Problems to be Solved by the Invention] Vora et al.
hananochemical Polishing of
Silicon Nitride ”includes silicon nitride and ceramics such as CaCO ₃ , MgO, SiO ₂ , and Fe.
It is described that wet mechanochemical polishing was carried out using soft abrasive grains such as ₂ O ₃ and Fe ₃ O ₄ , and Karaki et al., "Mechanochemical polishing mechanism for Si single crystal mechanochemical polishing" , Si single crystals were mechanochemically polished with ZrO ₂ abrasive grains in an alkaline solution. The "mechanochemical polishing of the ferrite material" Ochiai et al., Distilling the Mn-Zn-based single crystal ferrite water, sodium hydroxide, hydrochloric acid solution, there is described that the mechanochemical polishing with Al ₂ O ₃ abrasive grains .

Further, in Japanese Patent Laid-Open No. 64-64766, abrasive grains of metals, oxides, nitrides, suicides, borides, and carbides, which have excellent reactivity with the material to be processed, polyacetal, polyethylene, A grindstone material is described in which acrylonitrile, polyphenyl sulfide, phenol, and epoxy resin are molded so as to be softer than the material to be processed.

Of the above, the former of Vora, Karaki, Ochiai et al. Is the one in which mechanochemical polishing is performed using oxide abrasive grains, and the latter Japanese Patent Laid-Open No. 64-64766 discloses oxides, especially It describes a grindstone composed of oxide abrasive grains of Cr ₂ O ₃ , Fe ₂ O ₃ , and CeO ₂ and a resin.
Since the abrasive grains used for these are composed of a chemically stable metal oxide, the polishing effect is weak, and it is attempting to enhance the polishing effect by interposing a solvent. In this case, there is a problem that it is necessary to process for a long time, and the mirror surface state after processing, that is, the surface roughness cannot be satisfied.

The present invention has solved the above-mentioned problems. Specifically, the abrasive grains of an inorganic salt can be hardened with a resin to increase the surface roughness of a material to be processed which has a high polishing effect. The purpose is to provide a possible resin bond grindstone for precision processing.

[0009]

Means for Solving the Problems The inventors of the present invention shorten the processing time and improve the surface accuracy of the material to be processed by mirror-finishing the surface of the material to be processed made of a Si wafer for semiconductors and a ceramics sintered body. When I was studying, using a grindstone in which an inorganic salt softer than ultra-hard abrasive was hardened with a resin, mechanochemical polishing could be used for mirror finishing, and at this time, a grindstone containing a commercially available metal oxide was an acidic solution. Or, while it is necessary to perform wet-type mechanochemical polishing mediated by an alkaline solution, a grindstone containing an inorganic salt has a sufficient mechanochemical polishing effect even in a dry type, and as an effect thereof, It was found that influences on the surface such as stress, adhesion of oxygen, adhesion of oxide film, etc. do not occur, and the surface accuracy can be significantly improved.

The present invention has been completed based on the above findings.

That is, the resin bond grindstone for precision processing of the present invention is characterized by containing at least 30% by volume of abrasive grains of an inorganic salt.

The abrasive grains of the inorganic salt used in the present invention are, for example,
Oxalate, hydrochloride, bromate, iodate, nitrate, sulfuric acid
Salts, carbonates, oxalates, acetates can be mentioned.
Fluorine such as LiF, NaF, KF, KF ・ HF, etc.
Salt, LiCl, NaCl, KCl, NaClO₃, KC
10₃, Ba (ClO₃)₂, KClO_Four, NaClO_Four，
MgCl, BaCl, NiCl, CoCl, CaCl,
ZnCl, AlCl, CrCl, NH_FourHydrochloric acid such as Cl
Salt, NaBr, KBr, KBrO₃, NaBrO₃Odor
Phosphate, NaI, KI, KIO₃, KH (IO₃)₂, C
dI₂Iodates such as NaNO₂, NaNO₃, KN
O₂, KNO₃, Ca (NO₃)₂, Zn (NO₃)₂, Al
(NO₃)₃, AgNO₃, Co (NO₃)₂, ZrO (N
O₃)₂, Sr (NO₃)₂, Fe (NO₃)₂, Cu (NO
₃)₂, Pb (NO₃)₂, Ni (NO₃)₂, Ba (N
O₃)₂, Mg (NO₃)₂, LiNO₃Nitrates such as Na₂
SO_Four, Na₂SO₃, Na HSO₃, NaHSO_Four, K₂S
O_Four, K₂SO₃, KHSO₃, ZnSO_Four, Al (SO_Four)
₃, CdSO_Four, CaSO_Four, CoSO_Four, FeSO_Four, F
e₂(SO_Four)₃, CuSO_Four, NiSO_Four, BaSO_Four, M
gSO_Four, MnSO_Four, Etc. sulfate, Na₂CO₃, K₂C
O₃, CaCO₃, Li₂CO₃, BaCO₃Carbonic acid such as
Salt, Na₂C₂O_Four, K₂C₂O_Four, KH₃(C₂O_Four)₂Etc.
Acid salt, CH₃COONa, CH₃COOK, Zn (CH₃
COO)₂, Cd (CH₃COO)₂, Ca (CH₃CO
O)₂, Co (CH₃COO)₂, Cu (CH₃CO
O)₂, Pb (CH₃COO)₂, Ni (CH₃CO
O)₂, Ba (CH₃COO)₂, Mg (CH₃CO
O)₂, Mn (CH₃COO)₂, Acetate etc.
You can

Among these inorganic salt abrasives, alkali metal and alkaline earth metal hydrofluorates, hydrochlorides, bromates,
When the iodate is used, it is preferable because a super-hard object such as a cubic boron nitride sintered body or a diamond sintered body can be mirror-finished, and a fluorate is particularly preferable.

The finer the particles of the inorganic salt, the higher the activation, and the remarkable the improvement of the surface accuracy of the material to be processed. The average particle size is 50 μm or less, preferably 5 μm or less, and the standard deviation of the particle size distribution is Abrasive particles composed of uniform particles within σ, particularly preferably particles having an average particle size of 0.05 μm or less. If the abrasive grains are less than 30% by volume, the effect of improving the surface accuracy of the material to be processed is significantly reduced.

The resin bond grindstone for precision machining of the present invention is
In particular, the above-mentioned inorganic salt abrasive grains are 30 to 80 volumes, and the resin is 1
From the standpoint of strength of the grindstone, it is preferable that the content of the balance is 5 to 49% by volume and the balance is another substance containing a metal compound as a main component.

The resin in the present invention is not particularly limited, but when it is made of phenol, epoxy, polyimide, polystyrene or polyethylene, the formability and strength of the grindstone, the abrasive grains and other substances at the time of molding the grindstone. It is preferable because it has excellent dispersibility.

The other substance in the present invention is not particularly limited as long as it is a substance that has been conventionally used for a grindstone, and specifically, it includes super-hard abrasive grains, ceramic abrasive grains, glass, whiskers, fibers, Carbon can be mentioned,
More specifically, for example, Al ₂ O ₃ , SiO ₂ , Si
C, Fe ₂ O ₃ , Fe ₃ O ₄ , Cr ₂ O ₃ , ZrO ₂ , Ce
O _2, CBN, WBN, mention may be made of (wurtzite BN), diamond. Further, when the abrasive grains contained in the grindstone, which was invented by one of the present inventors and applied for a patent on May 30, 1991, is used as another substance, the effect is high.

The resin bond grindstone for precision machining of the present invention is
Conventional grinding wheel forming method, specifically, it is made by mixing abrasive grains and starting materials containing resin or other substances as necessary, sieving, and hot pressing with a mold. You can

[0019]

When the resin bond grindstone for precision machining of the present invention is used, the surface of the abrasive grains and the material to be machined are affected by the active force inherent in the abrasive grains of the inorganic salt and the frictional heat generated on the surface of the material to be machined. Primitively dissolved state to further enhance activation, to promote the chemical reaction between the abrasive grains and the material to be processed, in particular the surface etching effect of the material to be processed due to the decomposition of the inorganic salt, the so-called mechanochemical effect. ing. Further, the resin contained in the grindstone holds the abrasive grains of the inorganic salt and other substances, enhances the strength of the grindstone, and facilitates the contact between the abrasive grains of the inorganic salt and the surface of the work material during use. It is something that

[0020]

Example 1 Powders of various inorganic salts and various resins were used and blended as shown in Table 1 to obtain respective samples.

Each sample having the composition shown in Table 1 was mixed and sieved with a sanding machine, and then a grindstone was produced under the sintering conditions shown in Table 2.

[0022]

[Table 1]

[0023]

[Table 2] Inventive products 1 to 8 obtained according to Table 1 and Table 2 and comparative product 1
3 to 3 are commercially available silica sols, and the following conditions are used.
So I tried mirror finishing. Mirror polishing finish condition Work Material: Ceramics, Glass and Si shown in Table 3
The surface of the wafer was polished with a 1 μm diamond wheel
surface, Rotation speed: 200 rpm Processing pressure: 150g / cm² Polishing method: Dry method Evaluation: Surface roughness of the material to be processed at the specified polishing time
Surface state and grindstone of the work material after polishing for 60 minutes
Observation of the damage state.

The results of the above-mentioned mirror-polishing finishing test are shown in Table 3.

[0025]

[Table 3]

[0026]

The resin-bonded grindstone for precision processing of the present invention has the surface of the material to be processed by the abrasive grains of the inorganic salt contained in the grindstone and the friction heat generated on the surface of the material to be processed during use. It is a grindstone with a high effect of promoting the oxidation reaction, in which dissolution and oxidation on the order of sub-nanometers, oxide film formation and its film removal are repeated, compared to conventional grindstones containing abrasive grains Surface roughness (Rma
In x), it has a remarkable effect that it can be improved by about 5 to 242 times.

Claims (5)

[Claims] 1. A resin-bonded grindstone for precision processing, characterized by containing at least 30% by volume of abrasive grains of an inorganic salt. 2. The resin for precision processing according to claim 1, wherein the inorganic salt comprises at least one compound selected from the group consisting of an alkali metal and an alkaline earth metal and a halogen element. Bond whetstone. 3. The resin-bonded grindstone for precision machining according to claim 1, wherein the inorganic salt is particles having an average particle size of 50 μm or less. 4. The inorganic salt is 30 to 80% by volume, and the resin is 1
A resin-bonded grindstone for precision machining, comprising 5 to 49% by volume, and the balance being a metal, a compound of a metal, and / or another substance composed of ultra-hard abrasive grains. 5. The inorganic salt comprises an alkali metal fluoride, an alkaline earth metal fluoride and / or a mutual solid solution thereof, and the resin comprises phenol, epoxy, polyimide, polystyrene or polyethylene. The resin bond grindstone for precision processing according to claim 4.