Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M107/00—Lubricating compositions characterised by the base-material being a macromolecular compound
  • C10M107/20—Lubricating compositions characterised by the base-material being a macromolecular compound containing oxygen
  • C10M107/30—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • C10M107/32—Condensation polymers of aldehydes or ketones; Polyesters; Polyethers
  • C10M107/34—Polyoxyalkylenes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28D—WORKING STONE OR STONE-LIKE MATERIALS
  • B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
  • B28D5/0058—Accessories specially adapted for use with machines for fine working of gems, jewels, crystals, e.g. of semiconductor material
  • B28D5/007—Use, recovery or regeneration of abrasive mediums
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M173/00—Lubricating compositions containing more than 10% water
  • C10M173/02—Lubricating compositions containing more than 10% water not containing mineral or fatty oils
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2209/00—Organic macromolecular compounds containing oxygen as ingredients in lubricant compositions
  • C10M2209/02—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • C10M2209/08—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing monomers having an unsaturated radical bound to a carboxyl radical, e.g. acrylate type
  • C10M2209/084—Acrylate; Methacrylate
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2209/00—Organic macromolecular compounds containing oxygen as ingredients in lubricant compositions
  • C10M2209/10—Macromolecular compoundss obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • C10M2209/103—Polyethers, i.e. containing di- or higher polyoxyalkylene groups
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2209/00—Organic macromolecular compounds containing oxygen as ingredients in lubricant compositions
  • C10M2209/10—Macromolecular compoundss obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • C10M2209/103—Polyethers, i.e. containing di- or higher polyoxyalkylene groups
  • C10M2209/104—Polyethers, i.e. containing di- or higher polyoxyalkylene groups of alkylene oxides containing two carbon atoms only
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
  • C10N2020/01—Physico-chemical properties
  • C10N2020/02—Viscosity; Viscosity index
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
  • C10N2020/01—Physico-chemical properties
  • C10N2020/04—Molecular weight; Molecular weight distribution
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/02—Pour-point; Viscosity index
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/20—Metal working
  • C10N2040/22—Metal working with essential removal of material, e.g. cutting, grinding or drilling
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Definitions

• the present invention relates to an aqueous processing liquid, more specifically, an aqueous processing liquid used for cutting a fragile material with a fixed abrasive grain wire saw.
• a cutting method of the silicon ingot includes: a loose abrasive grain method of cutting the silicon ingot with a processing liquid in which grains are dispersed; and a fixed abrasive grain method of cutting the silicon ingot with a wire having grains fixed on its surface in advance.
• a processing liquid used for the loose abrasive grain method is exemplified by an aqueous processing liquid containing a friction-coefficient reducer, an anticorrosion adjuvant and the like.
• An unsaturated fatty acid is used as the friction-coefficient reducer contained in the processing liquid and benzotriazole is used as the anticorrosion adjuvant (see Patent Literature 1).
• a large margin is required when a thick wire is used, so that a large amount of cut powder is generated to deteriorate a yield after cutting the ingot.
• the wire becomes worn as being used there is a limit to reduce a diameter of the wire itself. Accordingly, the loose abrasive grain method is not productive in the manufacturing a silicon wafer for a solar battery and the like, which is expected to be significantly increasingly produced in the future.
• a water soluble processing liquid containing glycols has been known as the processing liquid used in the fixed abrasive grain method (see Patent Literatures 2 and 3).
• the processing liquid used in the fixed abrasive grain method since grains are fixed to the wire in advance, the diameter of the wire is reducible and the cut powder is less producible, thereby resulting in an excellent productivity.
• Patent Literature 1 JP-A-8-57848
• Patent Literature 2 JP-A-2003-82334
• Patent Literature 3 JP-A-2011-21096
• An object of the invention is to provide an aqueous processing liquid capable of inhibiting deflection of a small-diameter wire to provide a favorable cutting accuracy, even when a fragile material is cut with the wire.
• an aspect of the invention provides the following water soluble processing liquid.
• an aqueous processing liquid used for cutting a fragile material using a wire saw contains a water-soluble polymer, in which the water-soluble polymer has a mass average molecular weight in a range of 3 ⁇ 10 3 to 6 ⁇ 10 5 , and the aqueous processing liquid exhibits a viscosity at 25 degrees C. in a range of 1.5 mPa ⁇ s to 15 Pa ⁇ s.
• the wire saw is a fixed abrasive grain wire saw.
• the fixed abrasive grain wire saw has a wire diameter of 0.2 mm or less.
• a content of the water-soluble polymer is in a range of 0.5 mass % to 40 mass % of a total amount of the processing liquid.
• the aqueous processing liquid in the above aspect of the invention further contains at least one of a rust inhibitor, friction modifier, antifoaming agent, metal deactivator, bactericide (preservative) and pH adjuster.
• the fragile material is a silicon ingot.
• the aqueous processing liquid of the invention is particularly preferably usable for a fixed abrasive grain wire saw.
• an aqueous processing liquid in an exemplary embodiment (hereinafter, simply referred to as “the present processing liquid”) is used in processing a fragile material with a wire saw and contains a predetermined water-soluble polymer.
• a main component of the present processing liquid is water. Any water is usable without limitation, but purified water is preferably used and deionized water is particularly preferable.
• a content of water is preferably in a range of 50 mass % to 99 mass %, more preferably in a range of 60 mass % to 95 mass % of a total amount of the present processing liquid. At the content of 50 mass % or more, since inflammability of the present processing liquid is decreased, safety thereof is increased. Further, the content of 50 mass % or more is favorable in terms of an energy-saving performance and an environmental aspect.
• the upper limit of water is preferably determined at 99 mass % or less in relation to contents of other components.
• the present processing liquid may be prepared by blending the components (e.g., the water-soluble polymer) each by a required concentration at an initial step, or alternatively, a concentrated liquid (stock solution) may be prepared and then diluted in use.
• the concentrated liquid preferably has a volume magnification of approximately twice to 160 times in terms of handleability.
• a viscosity at 25 degrees C. of the present processing liquid is in a range of 1.5 mPa ⁇ s to 15 Pa ⁇ s, preferably in a range of 2 mPa ⁇ s to 10 mPa ⁇ s, more preferably in a range of 3 mPa ⁇ s to 8 mPa ⁇ s.
• adhesion to the wire is decreased to cause a poor lubrication, thereby decreasing the cutting accuracy.
• bite of grains to a workpiece is deteriorated. Consequently, the wire is heavily deflected to decrease the cutting accuracy.
• a mass average molecular weight of the water soluble polymer used in the present processing liquid is preferably in a range of 3 ⁇ 10 3 to 6 ⁇ 10 5 , more preferably in a range of 5 ⁇ 10 3 to 5 ⁇ 10 5 , further preferably in a range of 7 ⁇ 10 3 to 3 ⁇ 10 5 , most preferably in a range of 7 ⁇ 10 3 to 1 ⁇ 10 5 .
• the present processing liquid Since a viscosity-thickening effect is improved at 3 ⁇ 10 3 or more of the mass average molecular weight, the present processing liquid easily adheres to the wire to enter an interval between the wire and the material. Accordingly, since peeling of the grains from the wire can be effectively inhibited, the cutting speed can be increased. However, at more than 6 ⁇ 10 5 of the mass average molecular weight, a molecular chain is likely to be cut by shear, which may cause a large decrease in the viscosity.
• a processing liquid containing a water-soluble polymer having such a high molecular weight becomes inferior to a processing liquid containing a water-soluble polymer having an adequate molecular weight, even if both of the processing liquid has the same viscosity.
• the water-soluble polymer preferably has an oxygen-containing group in terms of processability.
• the oxygen-containing group are a carboxyl group, hydroxyl group, oxyethylene group, and oxypropylene group.
• the carboxyl group and the hydroxyl group include carboxyl group and hydroxyl group in a form of an anion obtained by deprotonation or neutralization.
• water-soluble polymer examples include poly(meth)acrylates, metal salts (e.g., Na, K) of poly(meth)acrylates, (meth)acrylate-maleate copolymer or metal salts (e.g., Na, K) thereof, (meth)acrylate-sulfonate copolymer or metal salts (e.g., Na, K) thereof, polyoxyalkylene glycol such as polyoxyethylene glycol and polyoxypropylene glycol, polyvinyl alcohol, a saponification product of an ethylene unsaturated monomer-vinyl acetate copolymer, and modified starch.
• metal salts e.g., Na, K
• poly(meth)acrylates metal salts (e.g., Na, K) of poly(meth)acrylates, (meth)acrylate-maleate copolymer or metal salts (e.g., Na, K) thereof, (meth)acrylate-sulfonate copolymer or metal salts (
• a content of the water-soluble polymer is preferably in a range of 0.5 mass % to 40 mass % in the present processing liquid, more preferably in a range of 1 mass % to 20 mass %, further preferably in a range of 2 mass % to 12 mass %.
• the viscosity of the present processing liquid is also controllable in a preferable range, so that advantages of the invention is more easily exhibited.
• the present processing liquid allows the fragile material (e.g., silicon ingot) to be cut at a high speed while the grains are prevented from dropping off, the fragile material can be cut at a high accuracy even using a fixed abrasive grain wire. Accordingly, the present processing liquid is extremely effective in using the fixed abrasive grain wire having a small diameter which requires cutting with a low tension.
• the fragile material e.g., silicon ingot
• a diameter of the fixed abrasive grain wire saw is preferably 0.2 mm or less, more preferably 0.12 mm or less, further preferably 0.1 mm or less, most preferably 0.08 mm or less.
• a yield at which a product is obtained from the fragile material (workpiece) can be increased.
• the diameter of the wire saw is preferably 0.06 mm or more in terms of strength.
• the present processing liquid may contain known additives such as a rust inhibitor, friction modifier, antifoaming agent, metal deactivator, bactericide (preservative) and pH adjuster as long as the effects of the invention is not impaired.
• rust inhibitor examples include alkylbenzenesulfonate, dinonylnaphthalenesulfonate, alkenyl succinate and polyhydric alcohol ester.
• a content of the rust inhibitor is preferably in a range of approximately 0.01 mass % to 5 mass % of a total amount of the processing liquid.
• the friction modifier is used for inhibiting abrasion of the grains.
• Various surfactants are usable as the friction modifier.
• a non-ionic surfactant e.g., glycols
• a content of the surfactant is preferably in a range of approximately 0.01 mass % to 5 mass % of the total amount of the processing liquid.
• the antifoaming agent is used for preventing the processing liquid from overflowing from a processing liquid tank provided in a processing room.
• the antifoaming agent are silicone oil, fluorosilicone oil, and fluoroalkylether.
• a content of the antifoaming agent is preferably in a range of approximately 0.001 mass % to 1 mass % of the total amount of the processing liquid.
• metal deactivator examples include imidazoline, pyrimidine derivative, thiadiazole, and benzotriazole.
• a content of the metal deactivator is preferably in a range of approximately 0.01 mass % to 5 mass % of the total amount of the processing liquid.
• the bactericide (preservative) is used for preventing decomposition of the processing liquid.
• examples of the bactericide (preservative) are paraoxy benzoic acid esters (parabens), benzoic acid, salicylic acid, sorbic acid, dehidroacetic acid, p-toluenesulfonic acids and salts thereof, and phenoxyethanol.
• a content of the bactericide (preservative) is preferably in a range of approximately 0.01 mass % to 1 mass % of the total amount of the processing liquid.
• the pH adjuster is used for adjusting pH of the processing liquid to fall within a range of 3 to 9. At the pH of less than 3, anticorrosiveness may be deteriorated. At the pH of more than 9, silicon may be corroded.
• Examples of the pH adjuster are an organic acid such as acetic acid, malic acid and citric acid, a salt of the organic acid, phosphoric acid and a salt thereof.
• Aqueous processing liquids (sample liquids) of compositions shown in Table 1 were prepared and subjected to the following cut processing for evaluation. Evaluation results are also shown in Table 1.
• a silicon ingot was cut by a fixed abrasive grain wire saw to obtain a silicon wafer while pouring the sample liquid over the wire saw, so that a silicon wafer was obtained.
• Specific conditions were as follows.
• Wire electrodeposited diamond wire (diameter: 0.08 mm, grain size: 8-16 ⁇ m)
• TTV total thickness variation
• SORI warpage
• TTV The flatness
• the warpage (SORI) is a parameter measured by a method defined by the technical standard QIAJ-B-007 established in Feb. 10, 2000 by Quartz Crystal Industry Association of Japan and represents undulation of the wafer in an unclamped condition by a maximum value of deviation from a flat surface (reference flat surface) in contact with a rear surface of the wafer.
• the warpage (SORI) was measured using Nanometro 44F manufactured by KURODA Precision Industries Ltd.
• a viscosity of the processing liquid was measured using B-type rotary viscometer TVB-10 (manufactured by TOKI SANGYO CO., LTD).
• sample liquids of Examples 1 to 6 contained a predetermined water-soluble polymer of the invention and the viscosity of each of the sample liquids was within a predetermined range, accuracy (TTV and SORT) of the cut silicon wafers was excellent. Moreover, the deflection of the wire during the cut processing was significantly decreased although the diameter of the wire was extremely small as much as 0.08 mm.
• Comparative 1 in which the sample liquid was 100 mass % of ion-exchange water containing no water-soluble polymer, the wire was broken during the cut processing.
• Comparative 2 since the viscosity of the sample liquid was excessively high, the accuracy (TTV and SORI) of the silicon wafer was extremely poor.
• Comparative 3 since the mass average molecular weight of the contained water-soluble polymer was excessively high although the viscosity of the sample liquid was within a predetermined range, accuracy (TTV and SORI) of the silicon wafer was also poor.
• An aqueous processing liquid of the invention is suitable for cutting a fragile material such as a silicon ingot using a fixed abrasive grain multi-wire saw.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Mechanical Engineering (AREA)
• Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Emergency Medicine (AREA)
• Mechanical Treatment Of Semiconductor (AREA)
• Processing Of Stones Or Stones Resemblance Materials (AREA)
• Lubricants (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)

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• 2012
  • 2012-06-29 JP JP2012147683A patent/JP6039935B2/ja active Active
• 2013
  • 2013-06-28 EP EP13808960.2A patent/EP2868741A4/en not_active Withdrawn
  • 2013-06-28 WO PCT/JP2013/067772 patent/WO2014003157A1/ja active Application Filing
  • 2013-06-28 CN CN201380033371.3A patent/CN104395448B/zh active Active
  • 2013-06-28 KR KR1020147033536A patent/KR102060953B1/ko active IP Right Grant
  • 2013-06-28 US US14/405,469 patent/US20150133354A1/en not_active Abandoned

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