Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B37/00—Lapping machines or devices; Accessories
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09G—POLISHING COMPOSITIONS; SKI WAXES
  • C09G1/00—Polishing compositions
  • C09G1/02—Polishing compositions containing abrasives or grinding agents
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P52/00—Grinding, lapping or polishing of wafers, substrates or parts of devices

Definitions

• the present invention relates to a polishing composition and a polishing method.
• the substrate for electronic parts is often formed of single crystal ceramics (for example, single crystal sapphire), but when the substrate for electronic parts is formed of polycrystalline ceramics, the shape is larger than that of single crystal ceramics. In some cases, advantageous properties such as high degree of freedom, low manufacturing cost, and excellent optical characteristics can be obtained.
• An object of the present invention is to provide a polishing composition and a polishing method capable of smoothly polishing the surface of polycrystalline ceramics.
• the polishing composition according to one aspect of the present invention is a polishing composition used for polishing an object to be polished containing polycrystalline ceramics, and contains abrasive grains and water, and has an average secondary order of abrasive grains.
• the gist is that the particle size is 5 nm or more and 40 nm or less.
• the polishing method according to another aspect of the present invention is intended to polish an object to be polished containing polycrystalline ceramics by using the polishing composition according to the above one aspect.
• the polishing composition of the present embodiment is a polishing composition used for polishing an object to be polished containing polycrystalline ceramics, and contains abrasive grains and water.
• the average secondary particle diameter of the abrasive grains is 5 nm or more and 40 nm or less.
• the polishing method of the present embodiment is a method of polishing an object to be polished containing polycrystalline ceramics by using the polishing composition of the present embodiment.
• polishing the object to be polished containing the polycrystalline ceramics using the polishing composition of the present embodiment it is possible to smoothly polish the surface of the polycrystalline ceramics having uneven steps at the grain boundary portions. Is. Therefore, for example, even when a substrate for electronic components is formed of polycrystalline ceramics, the surface can be smoothed, and the degree of freedom in shape is high, the manufacturing cost is low, and the optical characteristics are excellent as compared with single crystal ceramics. Etc. and other superior properties can be obtained.
• polishing composition and the polishing method of the present embodiment will be described in detail.
• 1. About the object to be polished
• the polishing composition and the polishing method of the present embodiment can be used for polishing an object to be polished containing polycrystalline ceramics. Since polycrystalline ceramics have uneven steps at the grain boundaries, it is difficult to obtain a sufficiently smooth surface by polishing. However, polishing using the polishing composition and polishing method of the present embodiment is sufficient. It is possible to obtain a smooth surface.
• the types of polycrystalline ceramics are not particularly limited, but are, for example, metal-containing oxides, metal-containing nitrides, metal-containing carbides, metal-containing boroides, and metal-containing fluorides. Among these, oxides containing a metal, nitrides containing a metal, and carbides containing a metal are preferable.
• metal-containing oxides metal-containing nitrides, and metal-containing carbides
• silicon-containing oxides silicon-containing nitrides, silicon-containing carbides, aluminum-containing oxides, and aluminum.
• a nitride containing the above, and an oxide containing ittrium are preferable.
• These polycrystalline ceramics are used as substrates for electronic components such as communication devices, power semiconductors, communication high frequency devices, and pressure sensors.
• the substrate is particularly required to have a smooth surface.
• the oxides containing silicon the nitrides containing silicon, the carbides containing silicon, the oxides containing aluminum, the nitrides containing aluminum, and the oxides containing yttrium, the oxidation containing aluminum in particular.
• At least one of the material and the nitride containing aluminum is preferable.
• silicon oxide such as quartz as an oxide containing silicon
• silicon nitride SiN
• silicon carbide SiO 2
• examples of the aluminum-containing oxide include alumina (Al 2 O 3 ) such as translucent alumina and spinel ( Mg Al 2 O 4 )
• examples of the aluminum-containing nitride include aluminum nitride (Al N).
• examples of the oxide containing yttrium include ytria (Y 2 O 3 ) and YAG (Y 3 Al 5 O 12 ).
• the object to be polished may be any one containing polycrystalline ceramics, and may be entirely formed of polycrystalline ceramics or a part thereof may be formed of polycrystalline ceramics. Further, the type of the polycrystalline ceramics contained in the object to be polished may be one kind or a plurality of kinds. Specific examples of the object to be polished include a sintered body of a powder of polycrystalline ceramics.
• abrasive grains contained in the polishing composition of the present embodiment is not particularly limited, but for example, abrasive grains containing silica (SiO 2 ) or diamond can be used.
• the type of silica is not particularly limited, and examples thereof include colloidal silica, fumed silica, sol-gel method silica, and precipitation method silica. These silicas may be used alone or in combination of two or more.
• colloidal silica is preferable from the viewpoint of more efficiently smoothing the surface of polycrystalline ceramics.
• the average secondary particle diameter of the abrasive grains contained in the polishing composition of the present embodiment needs to be 5 nm or more and 40 nm or less in order to sufficiently smooth the surface of the polycrystalline ceramics, but is 7 nm. It is preferably 35 nm or less.
• the surface of the single crystal ceramics can be easily sufficiently smoothed, so that the average secondary particle size is larger than the specific particle size (average secondary particles).
• Abrasive particles with a diameter larger than 40 nm) were used, but when polishing polycrystalline ceramics with crystal grain boundaries, the average secondary particle size is smaller than the specific particle size (average secondary particle size). It is important to use abrasive particles (abrasive particles of 5 nm or more and 40 nm or less).
• abrasive grains with an average secondary grain size larger than the specific grain size are used, the convex and concave portions of the grain boundaries are processed at the same time, so it is not possible to fill the grain boundary steps and a sufficiently smooth surface can be obtained.
• abrasive grains with an average secondary particle size smaller than the specific grain size are used, the abrasive grains do not come into contact with the concave portions of the grain boundary steps and only the convex portions are processed, so that the grain boundary steps are eliminated and the grain boundaries are sufficiently smooth.
• the surface can be obtained.
• the average secondary particle size of the abrasive grains can be measured using, for example, a laser diffraction / scattering type particle size distribution measuring device (for example, "LA-950" manufactured by HORIBA, Ltd.).
• the content of the abrasive grains in the polishing composition of the present embodiment is not particularly limited, but is preferably 1% by mass or more and 30% by mass or less, and is preferably 3% by mass or more and 25% by mass or less. It is more preferable to do so.
• a polishing composition having an abrasive grain content within the above range the surface of the polycrystalline ceramic can be polished more smoothly.
• the polishing composition of the present embodiment is a slurry containing the above-mentioned abrasive grains and water.
• Water functions as a dispersion medium or solvent that disperses abrasive grains and disperses or dissolves other components.
• a mixture of water and an organic solvent may be used as a dispersion medium or a solvent.
• the water used is preferably water containing as little impurities as possible from the viewpoint of suppressing the inhibition of the action of the above other components. Specifically, pure water, ultrapure water, or distilled water from which foreign substances have been removed through a filter after removing impurity ions with an ion exchange resin is preferable.
• the pH of the polishing composition of the present embodiment is not particularly limited, but is preferably 1.5 or more and 9.0 or less, and more preferably 2.0 or more and 8.5 or less. By using a polishing composition having a pH within the above range, the surface of the polycrystalline ceramic can be polished more smoothly.
• the pH of the polishing composition of the present embodiment may be adjusted by an additive pH adjuster. As the pH adjuster, one type may be used alone, or two or more types may be mixed or used.
• the polishing composition of the present embodiment may optionally contain an additive (for example, a pH adjuster) which is the above-mentioned other component.
• a pH adjuster known acids, bases, or salts thereof can be used.
• Specific examples of acids that can be used as a pH adjuster include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, boric acid, carbonic acid, hypophobic acid, phobic acid, and phosphoric acid, and formic acid, acetic acid, and propion.
• Acid butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid , 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelli acid, maleic acid, phthalic acid, malic acid, tartrate acid, citric acid, Examples thereof include organic acids such as lactic acid, diglycolic acid, 2-furancarboxylic acid, 2,5-furandicarboxylic acid, 3-furancarboxylic acid, 2-tetratetracarboxylic acid, methoxyacetic acid, methoxyphenylacetic acid, and phenoxy
• an inorganic acid sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid and the like are preferable from the viewpoint of improving the polishing speed, and when an organic acid is used as the pH adjuster, glycolic acid, succinic acid, maleic acid and the like are preferable.
• an organic acid glycolic acid, succinic acid, maleic acid and the like are preferable.
• Citric acid, tartrate acid, malic acid, gluconic acid, itaconic acid and the like are preferable.
• Bases that can be used as a pH adjuster include amines such as aliphatic amines and aromatic amines, organic bases such as tetraammonium hydroxide, hydroxides of alkali metals such as potassium hydroxide, and hydroxylation of alkaline earth metals. Things, ammonia and the like can be mentioned. Among these bases, potassium hydroxide and ammonia are preferable because of their availability.
• a salt such as an ammonium salt or an alkali metal salt of the acid may be used as a pH adjuster in place of the acid or in combination with the acid.
• a pH buffering action can be expected, and in the case of a salt of a strong acid and a strong base, a buffering action of pH can be expected.
• the amount of the pH adjuster added is not particularly limited, and the pH may be appropriately adjusted so that the polishing composition has a desired pH.
• the polishing composition of the present embodiment may further contain an additive other than the pH adjuster, if necessary, but from the viewpoint of polishing the surface of the polycrystalline ceramic more smoothly, the pH adjuster. It is preferable that it does not contain any additives other than.
• the polishing composition may contain additives such as a complexing agent, an etching agent, and an oxidizing agent, which have an effect of further increasing the polishing rate.
• the polishing composition may contain a water-soluble polymer (a copolymer, a salt thereof, or a derivative thereof) that acts on the surface of the object to be polished or the surface of the abrasive grains.
• the polishing composition may contain additives such as a dispersant that improves the dispersibility of the abrasive grains and a dispersion aid that facilitates the redispersion of the aggregates of the abrasive grains. Further, the polishing composition may contain known additives such as preservatives, fungicides and rust inhibitors.
• additives are known in many patent documents and the like as those that can be usually added in a polishing composition, and the type and amount of the additives are not particularly limited. However, when these additives are added, the amount added is preferably less than 1% by mass, and more preferably less than 0.5% by mass, respectively, with respect to the entire polishing composition. These additives may be used alone or in combination of two or more.
• complexing agents include inorganic acids, organic acids, amino acids, nitrile compounds, chelating agents and the like.
• the inorganic acid include sulfuric acid, nitric acid, boric acid, carbonic acid and the like.
• organic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-.
• Heptanoic acid 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, malein Examples thereof include acid, phthalic acid, malic acid, tartrate acid, citric acid, lactic acid and the like.
• Organic sulfuric acids such as methanesulfonic acid, ethanesulfonic acid, and isethionic acid can also be used.
• Salts such as alkali metal salts of inorganic or organic acids may be used in place of or in combination with the inorganic or organic acids.
• complexing agents glycine, alanine, malic acid, tartaric acid, citric acid, glycolic acid, isethionic acid, or salts thereof are preferable.
• chelating agents include carboxylic acid-based chelating agents such as gluconic acid, amine-based chelating agents such as ethylenediamine, diethylenetriamine, and trimethyltetraamine, ethylenediaminetetraacetic acid, nitrilotriacetic acid, hydroxyethylethylenediaminetriacetic acid, and triethylenetetramine.
• carboxylic acid-based chelating agents such as gluconic acid
• amine-based chelating agents such as ethylenediamine, diethylenetriamine, and trimethyltetraamine
• ethylenediaminetetraacetic acid nitrilotriacetic acid, hydroxyethylethylenediaminetriacetic acid, and triethylenetetramine.
• polyaminopolycarboxylic acid-based chelating agents such as hexaacetic acid and diethylenetriaminepentaacetic acid.
• etching agents include inorganic acids such as nitrate, sulfuric acid, hydrochloric acid, phosphoric acid and hydrofluoric acid, organic acids such as acetic acid, citric acid, tartaric acid and methanesulfonic acid, potassium hydroxide, sodium hydroxide and ammonia.
• examples thereof include inorganic alkalis such as amines and organic alkalis such as quaternary ammonium hydroxide.
• the oxidizing agent include hydrogen peroxide, peracetic acid, percarbonate, urea peroxide, perchlorate, persulfate, nitric acid, potassium permanganate and the like.
• water-soluble polymers may be copolymers, salts thereof, derivatives
• examples of water-soluble polymers include polycarboxylic acids such as polyacrylates, polyphosphonic acids, polysulfonic acids such as polystyrene sulfonic acid, chitansan gum, sodium alginate and the like.
• examples thereof include the polysaccharides of the above, and cellulose derivatives such as hydroxyethyl cellulose and carboxymethyl cellulose.
• polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, sorbitan monooleate, an oxyalkylene polymer having a single type or a plurality of types of oxyalkylene units, and the like can also be mentioned as examples of the water-soluble polymer.
• Examples of the dispersion aid include pyrophosphate, condensed phosphate such as hexamethaphosphate, and the like.
• Examples of preservatives include sodium hypochlorite and the like.
• Examples of antifungal agents include oxazolines such as oxazolidine-2,5-dione.
• Examples of the anticorrosive agent include surfactants, alcohols, polymers, resins, amines, pyridines, tetraphenylphosphonium salts, benzotriazoles, triazoles, tetrazole, benzoic acid and the like.
• the surfactant examples include a nonionic surfactant, an anionic surfactant, a cationic surfactant, and an amphoteric surfactant.
• examples of the nonionic surfactant include ether type, ether ester type, ester type and nitrogen-containing type, and examples of the anionic surfactant include carboxylate, sulfonate, sulfate ester and phosphoric acid ester salt. Can be mentioned.
• Examples of the cationic surfactant include an aliphatic amine salt, an aliphatic quaternary ammonium salt, a benzalkonium chloride salt, a benzethonium chloride, a pyridinium salt and an imidazolinium salt, and examples of the amphoteric surfactant include carboxy. Examples thereof include betaine type, aminocarboxylate, imidazolinium betaine, lecithin, and alkylamine oxide.
• the manufacturing method of the polishing composition of this embodiment is not particularly limited, and it is manufactured by stirring and mixing abrasive grains and various additives in water, if desired. be able to.
• the temperature at which each component is mixed is not particularly limited, but is preferably 10 ° C. or higher and 40 ° C. or lower, and may be heated in order to improve the dissolution rate. Further, the mixing time is not particularly limited.
• the polishing composition of the present embodiment may be a one-dosage form, or may be a two-dosage form or a multi-dosage form in which a part or all of the components of the polishing composition are mixed at an arbitrary ratio. good. Further, the polishing composition of the present embodiment may be prepared by diluting the undiluted solution of the polishing composition with water, for example, 10 times or more.
• the order of mixing and diluting the two raw material compositions which are the raw materials of the polishing composition is arbitrary. For example, one raw material composition may be diluted with water and then mixed with the other raw material composition, both raw material compositions may be mixed and diluted with water at the same time, or both. The raw material composition of the above may be mixed and then diluted with water.
• polishing device and polishing method The polishing composition of the present embodiment can be used, for example, in a polishing device and polishing conditions generally used for polishing an object to be polished made of single crystal ceramics or polycrystalline ceramics.
• a polishing device a general single-sided polishing device or double-sided polishing device can be used.
• a holder called a carrier is used to hold the object to be polished, and while supplying the polishing composition, a surface plate to which a polishing pad is attached is attached to one side of the object to be polished.
• One side of the object to be polished is polished by pressing it against the surface and rotating the surface plate.
• a carrier When polishing using a double-sided polishing device, a carrier is used to hold the object to be polished, and while supplying the polishing composition, a platen to which a polishing pad is attached is pressed against both sides of the object to be polished for polishing. Both sides of the object to be polished are polished by rotating the pad and the object to be polished in opposite directions. Regardless of which polishing device is used, the object to be polished is due to the physical action of friction between the polishing pad and the composition for polishing and the object to be polished, and the chemical action that the composition for polishing brings to the object to be polished. Is polished.
• the type of polishing pad is not particularly limited, and those having various physical properties such as material, thickness, and hardness can be used.
• Examples of the material of the polishing pad include polyurethane, epoxy resin, non-woven fabric, suede and the like.
• the polished surface to be polished in contact with the object to be polished preferably has a C hardness of 94 or more.
• the C hardness is the hardness immediately after the pressed surface is in close contact with the test method specified in Annex 2 “Spring hardness test type C test method” of JIS K7312: 1996.
• the pressure surface of the tester when the pressure surface of the tester is brought into close contact with the surface of the test piece, the distance at which the push needle protruding from the hole in the center of the pressure surface by the spring pressure is pushed back by the test piece.
• the structure shown on the scale as the hardness is used.
• the measuring surface of the test piece shall be at least larger than the pressurized surface of the testing machine. Further, it is preferable that the surface of the polishing pad has grooves such as a grid pattern. If the surface of the polishing pad has grooves, the smoothness of the surface to be polished of the object to be polished is improved.
• the surface roughness Ra of the polishing pad is preferably 0.75 ⁇ m or less, and more preferably 0.1 ⁇ m or less. When the surface roughness of the polishing pad is in this range, the variation in the thickness (TTV) of the object to be polished in the polishing batch is reduced.
• the method for reducing the surface roughness Ra of the polishing pad is not particularly limited, but a method of dressing between batches using a dresser containing abrasive grains such as diamond is preferable.
• the average particle size of the abrasive grains such as diamond contained in the dresser is preferably 10 ⁇ m or less, more preferably 5 ⁇ m or less, and most preferably 2 ⁇ m or less. When the average particle size of the dresser's abrasive grains is in this range, the variation in the thickness (TTV) of the object to be polished in the polishing batch is reduced.
• the supply amount of the polishing composition is not particularly limited, but 20 mL or more per minute is preferable, and 100 mL or more is more preferable. When the supply amount of the polishing composition is within this range, the smoothness of the surface to be polished of the object to be polished is improved.
• Example ⁇ Examples and comparative examples are shown below, and the present invention will be described in more detail.
• Abrasive grains made of colloidal silica and water were mixed to disperse the abrasive grains in water to produce polishing compositions of Examples 1 to 10 and Comparative Examples 1 to 7.
• the average secondary particle diameter of the abrasive grains used in each Example and Comparative Example and the content of the abrasive grains in the polishing composition are as shown in Table 1.
• the average secondary particle size of colloidal silica was measured using a laser diffraction / scattering type particle size distribution measuring device LA-950 manufactured by HORIBA, Ltd.
• the object to be polished is a plate-shaped member formed of a sintered body of a powder of translucent alumina, aluminum nitride, or silicon nitride, which is a polycrystalline ceramic.
• the polishing pad was dressed with a dresser containing diamond having a particle size of # 270 (53 ⁇ m), and the surface roughness Ra of the polishing pad was set to 1.1 ⁇ m. Then, the surface roughness Ra of the surface to be polished and the step (unevenness step of the crystal grain boundary portion) of the surface to be polished were measured, and the polishing speed was calculated.
• polishing conditions are as follows. Polishing device: Single-sided polishing device EJ-380IN manufactured by Engis (surface plate diameter 380 mm) Polishing pad: Epoxy resin polishing pad Polishing load: 29.4 kPa (300 gf / cm 2 ) Surface plate rotation speed: 110min -1 Polishing speed (linear speed): 84 m / min Polishing time: 30 minutes Supply speed of polishing composition: 20 mL / min
• the surface roughness Ra of the surface to be polished of the object to be polished after polishing was measured under the condition of a viewing angle of 143 ⁇ 107 ⁇ m using a measuring device NewView5032 manufactured by Zygo.
• the step on the surface to be polished of the object to be polished after polishing was measured as follows. That is, the step on the surface to be polished of the object to be polished after polishing was evaluated by the value of PV using a measuring device NewView5032 manufactured by Zygo.
• the PV value is a value indicating the maximum height and the maximum depth in the measurement range, but since the viewing angle (viewing angle 143 ⁇ 107 ⁇ m) this time is not affected by the swell, the maximum height is the remaining part of the crystal (the remaining part of the crystal (viewing angle 143 ⁇ 107 ⁇ m).
• the convex portion) and the maximum depth are the deciduous portions (concave portions) of the crystal, and the grain boundary step correlates with the PV value.
• silicon nitride the correlation between the PV value and the grain boundary step is low, and the grain boundary step cannot be accurately measured by this method, so the evaluation has not been performed.
• the polishing speed was calculated from the difference, the polishing time, and the area of the surface to be polished by measuring the mass of the object to be polished before and after polishing. These results are shown in Table 1 (the step of silicon nitride is shown as "ND").
• Comparative Examples 2 to 7 since the average secondary particle diameter of the abrasive grains exceeds 40 nm, the step of the surface to be polished of the object to be polished after polishing is large, and the object to be polished made of polycrystalline ceramics. The surface of the ceramic could not be polished smoothly. Since it is difficult to stably produce abrasive grains having an average secondary particle diameter of less than 5 nm, Comparative Example 1 could not be compared and examined.
• a dresser containing diamond having a grain size of # 270 (53 ⁇ m) was used as a dresser between polishing batches, and a dresser containing diamond having a grain size of 1 ⁇ m was used for dressing.
• the surface roughness Ra of the polishing pad was set to 0.05 ⁇ m and the polishing was performed in the same manner, the polishing was performed in the same manner as when the surface roughness Ra of the polishing pad was 1.1 ⁇ m and the dresser containing diamond having a grain size of # 270 (53 ⁇ m) was used.
• the variation in the thickness of the object to be polished (TTV) in the polishing batch was reduced to 60 to 80%.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
• Mechanical Treatment Of Semiconductor (AREA)

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• 2021
  • 2021-07-09 JP JP2022535406A patent/JP7671756B2/ja active Active
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