WO2004038744A1 - 積層セラミックコンデンサの製造方法 - Google Patents
積層セラミックコンデンサの製造方法 Download PDFInfo
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- WO2004038744A1 WO2004038744A1 PCT/JP2003/013668 JP0313668W WO2004038744A1 WO 2004038744 A1 WO2004038744 A1 WO 2004038744A1 JP 0313668 W JP0313668 W JP 0313668W WO 2004038744 A1 WO2004038744 A1 WO 2004038744A1
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- WIPO (PCT)
- Prior art keywords
- raw material
- powder
- multilayer ceramic
- medium
- ceramic capacitor
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- 239000003985 ceramic capacitor Substances 0.000 title claims abstract description 40
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 19
- 238000000034 method Methods 0.000 title claims abstract description 16
- 239000000843 powder Substances 0.000 claims abstract description 137
- 239000002245 particle Substances 0.000 claims abstract description 97
- 238000002156 mixing Methods 0.000 claims abstract description 70
- 239000002994 raw material Substances 0.000 claims abstract description 70
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 claims abstract description 49
- 229910002113 barium titanate Inorganic materials 0.000 claims abstract description 49
- 239000002609 medium Substances 0.000 claims abstract description 42
- 239000002002 slurry Substances 0.000 claims abstract description 38
- 239000000203 mixture Substances 0.000 claims abstract description 33
- 238000001035 drying Methods 0.000 claims abstract description 24
- 239000002612 dispersion medium Substances 0.000 claims abstract description 18
- 239000011230 binding agent Substances 0.000 claims abstract description 14
- 238000010304 firing Methods 0.000 claims abstract description 4
- 239000000919 ceramic Substances 0.000 claims description 22
- 238000001354 calcination Methods 0.000 claims description 20
- 238000003756 stirring Methods 0.000 claims description 16
- 238000010298 pulverizing process Methods 0.000 claims description 15
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 12
- 239000002904 solvent Substances 0.000 claims description 8
- 239000003990 capacitor Substances 0.000 claims description 4
- 238000000227 grinding Methods 0.000 claims description 3
- 238000010030 laminating Methods 0.000 claims description 2
- 239000013078 crystal Substances 0.000 abstract description 15
- 239000000463 material Substances 0.000 abstract description 4
- 238000007493 shaping process Methods 0.000 abstract 1
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 70
- 239000010410 layer Substances 0.000 description 18
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 17
- 239000007858 starting material Substances 0.000 description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 12
- 230000002776 aggregation Effects 0.000 description 10
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 9
- 229910052726 zirconium Inorganic materials 0.000 description 9
- 238000004220 aggregation Methods 0.000 description 8
- 238000001179 sorption measurement Methods 0.000 description 8
- 239000004014 plasticizer Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 5
- DKPFZGUDAPQIHT-UHFFFAOYSA-N butyl acetate Chemical compound CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 description 4
- 229910044991 metal oxide Inorganic materials 0.000 description 4
- 150000004706 metal oxides Chemical class 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 230000000996 additive effect Effects 0.000 description 3
- 238000003801 milling Methods 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- IRIAEXORFWYRCZ-UHFFFAOYSA-N Butylbenzyl phthalate Chemical compound CCCCOC(=O)C1=CC=CC=C1C(=O)OCC1=CC=CC=C1 IRIAEXORFWYRCZ-UHFFFAOYSA-N 0.000 description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 229910021523 barium zirconate Inorganic materials 0.000 description 2
- DQBAOWPVHRWLJC-UHFFFAOYSA-N barium(2+);dioxido(oxo)zirconium Chemical compound [Ba+2].[O-][Zr]([O-])=O DQBAOWPVHRWLJC-UHFFFAOYSA-N 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 2
- 239000002270 dispersing agent Substances 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000007606 doctor blade method Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- -1 polyethylene terephthalate Polymers 0.000 description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- KOAWAWHSMVKCON-UHFFFAOYSA-N 6-[difluoro-(6-pyridin-4-yl-[1,2,4]triazolo[4,3-b]pyridazin-3-yl)methyl]quinoline Chemical compound C=1C=C2N=CC=CC2=CC=1C(F)(F)C(N1N=2)=NN=C1C=CC=2C1=CC=NC=C1 KOAWAWHSMVKCON-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- VONGZNXBKCOUHB-UHFFFAOYSA-N Phenylmethyl butanoate Chemical compound CCCC(=O)OCC1=CC=CC=C1 VONGZNXBKCOUHB-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000002003 electrode paste Substances 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen(.) Chemical compound [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 231100000989 no adverse effect Toxicity 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- LLZRNZOLAXHGLL-UHFFFAOYSA-J titanic acid Chemical compound O[Ti](O)(O)O LLZRNZOLAXHGLL-UHFFFAOYSA-J 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/30—Stacked capacitors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/002—Details
- H01G4/018—Dielectrics
- H01G4/06—Solid dielectrics
- H01G4/08—Inorganic dielectrics
- H01G4/12—Ceramic dielectrics
- H01G4/1209—Ceramic dielectrics characterised by the ceramic dielectric material
- H01G4/1218—Ceramic dielectrics characterised by the ceramic dielectric material based on titanium oxides or titanates
- H01G4/1227—Ceramic dielectrics characterised by the ceramic dielectric material based on titanium oxides or titanates based on alkaline earth titanates
Definitions
- the present invention relates to a method for manufacturing a multilayer ceramic capacitor.
- the capacitance of multilayer ceramic capacitors is measured under AC voltage, not under DC voltage.
- a DC voltage is always applied, and the application of this DC voltage reduces the capacitance of most capacitors. Therefore, an excellent DC bias characteristic, which indicates the rate of decrease in capacitance due to the application of a DC voltage, is desired.
- barium titanate powder as a main component and metal oxide powder as a minor component as a minor additive are mixed with water as a dispersing medium and zirconia balls as a mixing medium to form barium titanate and a metal oxide.
- water a dispersing medium
- zirconia balls as a mixing medium
- the zirconia balls are removed from the slurry and dried to obtain a mixed powder.
- an organic substance such as a binder and a plasticizer is mixed with the mixed powder to prepare a ceramic green sheet.
- the ceramic green sheets and the internal electrodes are alternately laminated, the laminated body is fired, and finally the external electrodes are formed, thereby obtaining a laminated ceramic capacitor.
- barium zirconate titanate powder or barium titanate powder which is the main component, is excessively pulverized, the particle size variation of the powder becomes large, and the small particles that are excessively pulverized promote grain growth during firing, resulting in crystal growth. The size of the particles increases.
- an object of the present invention is to provide a multilayer ceramic capacitor having excellent DC bias characteristics by suppressing the variation of crystal grains. Disclosure of the invention
- the present invention relates to a raw material powder mainly composed of barium titanate powder and a dispersion medium,
- a slurry containing the mixture of the raw material powders is prepared by stirring with a mixing medium and then dried to obtain a mixture of the raw material powders, the mixed medium having a smaller particle size than before is used, so that the excess amount of barium titanate can be obtained. It is intended to prevent excessive force from being applied and resulting in excessive pulverization.
- the method of the present invention it is possible to obtain a multilayer ceramic capacitor that suppresses variation in crystal particle size and has excellent DC bias characteristics.
- the present invention provides a first step in which a raw material powder mainly composed of barium titanate powder and a dispersion medium are charged into a mixing tank and stirred with a pole of the mixing medium to obtain a slurry containing the mixture of the raw material powders.
- a second step of drying the mixture to obtain a mixture of the raw material powders a third step of molding the mixture of the raw material powders together with a binder to form a green sheet,
- a method for manufacturing a multilayer ceramic capacitor having a particle size of 100 times or less.
- FIG. 1 is a longitudinal sectional view of a mixing tank for performing a mixing step according to an embodiment of the present invention.
- FIG. 2 is a perspective view of the laminated ceramic capacitor 20 obtained according to the embodiment of the present invention, with a part thereof being cut away.
- the present invention is directed to a method of mixing a raw material powder mainly composed of barium titanate powder, that is, a raw material powder obtained by adding a metal oxide powder as a sub-component to a powder of barium titanate to uniformly mix the particles of a pole of a mixing medium. Regulate the diameter.
- a pole having a particle diameter of 400 times or less based on the particle diameter of the raw material barium titanate powder is used as the pole of the mixed medium.
- the particle size of the raw material barium titanate powder is preferably 0.1 to 1.0 Om, and more preferably 0.1 to 0.5 m.
- the preferred particle size of the mixed medium is not more than 200 im. It is more preferably 100 im or less, and further preferably 50 m or less.
- the particle size of the mixed medium is at least 50 times the particle size of the raw material palladium titanate powder, specifically 25 It is preferable to have the degree.
- the amount of the dispersing medium is preferably 1 to 3 times the volume of the raw material powder.
- the surface of the raw material powder is first coated with a dispersion medium, that is, wetted with the dispersion medium and then brought into contact with the mixed medium.
- a dispersion medium that is, wetted with the dispersion medium and then brought into contact with the mixed medium.
- the temperature of the dispersion medium in the first step is preferably 50 ° C. or lower. Thereby, a change in energy applied to the raw material powder can be suppressed. It is preferable that the amount of the mixed medium in the first step occupies 60 to 74% of the internal volume of the mixing tank. As a result, the barium titanate powder as the raw material powder and the metal oxide powder as the accessory component can be efficiently mixed.
- the drying temperature in the second step is preferably set to 120 ° C. or lower. As a result, aggregation of the raw material powder can be suppressed, and the variation in the crystal particle diameter can be reduced. It is preferable that the second step further includes a step of dehydrating the slurry before drying. As a result, aggregation of the raw material powder can be suppressed, and variation in the crystal particle diameter can be reduced.
- barium titanate which is the main component, and subcomponents change appropriately, and the variation in the crystal grain size can be reduced.
- the pulverizing medium one having a particle size equal to or larger than that of the mixed medium used in the first step is used, and it is preferable that the pulverizing medium be 200 jam or less. This is for suppressing the calcined powder from being excessively pulverized.
- the calcined powder preferably has a specific surface area of 0.5 to 1 times the specific surface area of the raw material parium titanate powder.
- the fired dielectric layer is composed of crystal grains having a desired particle size.
- the mixture of the raw material powder, the organic binder and the solvent are stirred together with a third mixed medium having a particle diameter of 400 times or less the average particle diameter of the raw material barium titanate.
- the method comprises a step of obtaining a slurry and a step of forming a green sheet from the slurry, which suppresses excessive pulverization due to excessive force applied to barium titanate. By suppressing this, a multilayer ceramic capacitor having excellent DC bias characteristics can be obtained.
- FIG. 1 is a vertical sectional view of a mixing tank for performing a mixing step in the present embodiment.
- the mixing tank 10 is composed of a cylindrical container 11 and a lid 12 for closing the upper opening thereof, and is filled with a zirconia pole 13 as a mixing medium.
- Reference numeral 14 denotes a stirring rod inserted through the lid 12 into the mixing tank, and has a plurality of stirring pieces 15.
- the lid 12 has a sample inlet 16.
- the container 11 has a sample outlet 17 on the side surface.
- FIG. 2 is a perspective view showing a multilayer ceramic capacitor 20 obtained by the present embodiment with a part thereof cut away.
- Reference numeral 21 denotes a dielectric layer containing titanium titanate as a main component
- 22 and 23 denote internal electrodes
- 24 and 25 denote external electrodes connected to the internal electrodes 22 and 23, respectively.
- barium titanate Omo 1 as the starting material of the dielectric layer the MgO as subcomponent 1.
- the MgO as subcomponent 1.
- Dy 2 0 3 to 0. 3mo l
- Ho 2 ⁇ 3 0. 3mo l the S I_ ⁇ 2 Weigh 0.6 mol and Mn 3 O 4 at a rate of 0.05 mol, respectively.
- Barium titanate having an average particle size of 0.50 / m and 0.32 im was used.
- the average particle size of the accessory components is 0.1 m or less, and may include a few nm.
- this starting material powder is mixed, water as a dispersion medium is added and further mixed, and the surface of the starting material powder is coated with water.
- the amount of the dispersion medium is desirably 1 to 3 times the volume of the starting material.
- a dispersing agent that enhances the dispersibility of the raw material powder may be added.
- a rotatable stirring rod 14 is provided inside the mixing tank 10, and a zirconium alcohol 13 having an average particle diameter of 200 is packed in a close-packed manner. You.
- the zirconia pole 13 occupies about 70% of the internal volume of the mixing tank 10 excluding the volume of the stirring rod 14.
- the volume of the mixing tank 10 is, for example, 0.5 liter.
- the mixture of water and raw material powder is fed at a predetermined speed, for example, 0. Flow in at 1-1.0 liter / min.
- the mixture of water and the raw material powder flows out of the outlet 17 through the gap of the zirconia 13.
- Filters are installed at the inlet 16 and the outlet 17 of the mixing tank 10 so that foreign matter is prevented from entering the mixing tank 10 and only the slurry flows from the outlet 17. It is coming out.
- the raw material powder including barium titanate collides with zirconia pole and is slightly ground.
- the particle size of zirconia apor is much smaller than before, barium titanate can be prevented from being excessively impacted and excessively pulverized.
- the mixing tank 10 be packed with spherical zirconia poles in a close-packed manner.
- zirconium apol- etically occupies 74% of the internal volume of the mixing vessel 10. If the content of zirconia is less than 60% of the internal volume of the mixing tank 10, the mixing of the powder cannot be performed sufficiently, and the dispersibility will be poor. Multilayer ceramic capacitors obtained from such raw material powders have poor reliability.
- the zirconia pole 13 occupies 60 to 74%, preferably 70 to 74% of the internal volume (excluding the volume of the stirring rod) of the mixing tank 10.
- the rotation speed of the stirring rod 14 and the inflow speed of the mixture are controlled so that excessive force is not applied to barium titanate. For example, set the peripheral speed of the stir bar to 6 mZ seconds and the inflow speed of the mixture to about 0.3 to 0.5 liter Z minutes. I do.
- the slurry is filtered and dehydrated, and dried in a drying room at an indoor temperature of 120 ° C.
- the raw material powder can be prevented from agglomerating during drying.
- the dried powder is calcined at 800 to 100 ° C. in the air.
- the optimal calcination temperature is selected according to the composition.
- the calcining temperature and time should be such that the reaction between barium titanate and the subcomponent can be confirmed by X-ray diffraction of the calcined powder obtained.
- the specific surface area of the powder after calcination and milling should be 0.5 to 1 times the specific surface area of the starting material barium titanate, and the calcination temperature and Control the time.
- the calcining causes not only the above reaction but also a partial reaction between the raw material powders. Therefore, it is crushed.
- the amount of water as a dispersion medium added at the time of pulverization is too small, the dispersibility of the calcined powder is reduced, and if it is too large, coagulated powder is easily generated in the drying step. Therefore, the amount of the dispersion medium to be added is desirably 1 to 3 times the volume of the calcined powder.
- a dispersant that increases the dispersibility of the calcined powder may be added.
- the pulverization of the calcined powder is performed using a tank 10 as shown in FIG. At this time, the calcined powder collides with the zirconia pole 13 and is pulverized. However, since the particle diameter of zirconia pole 13 is much smaller than in the past, it is possible to suppress excessive crushing of the calcined powder due to excessive impact.
- the calcined powder is slightly reacted and therefore has a larger particle size than the starting material. There is a high possibility that it is sharp. Therefore, in order to appropriately pulverize and mix the calcined powder, use a zirconiapole having a size equal to or larger than that used when mixing the starting materials, preferably 200 m or less. Is desirable.
- the mixing tank 10 be filled with zirconium alcohol 13 in a close-packed manner. With close packing, the zirconia theoretically occupies 74% of the internal volume of the mixing vessel 10. If the content of the zirconia pole is less than 60% of the internal volume of the mixing tank 10, mixing cannot be performed sufficiently, and the dispersibility will be poor. Therefore, a multilayer ceramic capacitor obtained from such a raw material powder has poor reliability.
- the zirconia balls used here occupy 60 to 74%, preferably 70 to 74% of the internal volume of the mixing tank 10.
- the rotation speed of the stirring rod 14 and the inflow speed of the mixture are controlled so that excessive force is not applied to the calcined powder.
- the slurry is filtered and dehydrated, and dried in a drying room at an indoor temperature of 120 ° C.
- the drying is preferably performed at room temperature of 120 ° C or lower, more preferably at 100 to 120 ° C, as in the first mixing step.
- a slurry for preparing a green sheet is prepared using the dried calcined powder.
- alcohol such as ethanol is mixed with the calcined powder so that the surface of the calcined powder particles is coated with the alcohol.
- the calcined powder was mixed with n-butyl acetate as a solvent, benzyl butyrate as a plasticizer, and a polybierbutyral resin as a binder. Get a slurry.
- the surface of the calcined powder particles is first coated with the alcohol, and then mixed with a solvent, a plasticizer, and a binder, whereby aggregation of the calcined powder particles can be suppressed.
- the amount of the alcohol used here is such that the agglomeration of the calcined powder particles is suppressed and the surface thereof can be coated, and is smaller than the total amount of the solvent, the plasticizer, and the binder.
- a ceramic green sheet to be a dielectric layer is formed on a suitable support, for example, a sheet of polyethylene terephthalate, using the slurry by a doctor blade method.
- an internal electrode paste made of Ni powder having an average particle size of about 0.41 is screen-printed so as to have a desired pattern.
- the heating temperature in this case is 80 ⁇ : L 40 ° C, and the pressure is 100 ⁇ 200 kgf Zc m 2 . This is cut to a size of 2.4 mm in width and 1.3 mm in length to obtain a green laminate.
- this unsintered laminate is placed in a sheath made of zirconia on which zirconia powder is spread, and heated in an atmosphere furnace to 350 ° C. in a nitrogen stream to burn the organic binder. Then, it is fired in a mixed gas stream of nitrogen and hydrogen gas at 110 to 1300 ⁇ to obtain a sintered body. In the following example, baking was performed at 125 ° for 2 hours.
- a copper paste was applied to each of the exposed end faces of the internal electrodes of the obtained sintered body, and the resultant was sintered in a nitrogen atmosphere in a mesh type continuous belt furnace. It is baked at 900 ° C to obtain a multilayer ceramic capacitor as shown in Fig. 2.
- two types of barium titanate having an average particle size of 0.50 m and 0.32 ⁇ m were used, and sub-components were added to parium titanate of each average particle size.
- the multilayer ceramic capacitor was manufactured by changing the diameter of the zirconia pole used for mixing to 500 m, 200 m, 100 m, and 50 m. Table 1 shows the results of measuring the DC bias characteristics of the obtained multilayer ceramic capacitor. For grinding of the calcined powder and preparation of a slurry for forming a green sheet, a zirconia-pore having a diameter of 500 m was used.
- the DC bias characteristics were measured as follows. First, the multilayer ceramic capacitor was held at 150 at 1 hour, and then at 20 ° C. for 24 hours. Next, the capacitance was measured without applying a DC voltage. Then, a DC voltage of 3.15 V was applied to the same sample, the capacitance was measured, and the rate of decrease in that value relative to the value before the DC voltage was applied was defined as the DC bias characteristic. According to Table 1, as shown in Sample Nos. 2 to 4, 7, and 8, when the particle diameter of zirconium is 400 times or less the average particle diameter of the raw material titanium titanate. In this case, the DC bias characteristic is as small as 130% or less, which is excellent. In other words, these dielectric layers have small crystal grains and small variations in the grain size. In addition, the smaller the particle size of the zirconia-pore used for mixing, the better the DC bias characteristics.
- the DC bias characteristic becomes ⁇ 30%. This is not preferable in terms of the characteristics of the capacitor. This is because barium titanate is excessively pulverized at the time of mixing, which promotes grain growth of the dielectric layer at the time of sintering, resulting in a large variation in crystal grain size.
- the particle size of barium titanate used as a starting material and its variation, and the particle size of the raw material powder after wet mixing and drying, and its variation are as follows: It is important that they match as closely as possible.
- the particle size of the zirconia pole used for mixing was set to 50, and the size of the zirconia pole at the time of pulverizing the calcined powder was changed to produce a multilayer ceramic capacitor.
- Table 2 shows the results of measuring the DC bias characteristics. Samples No. 4A to 4D have an average particle size of barium titanate powder of 0.50 m, and No. 8 A to 8D have an average particle size of barium titanate powder of 0.32 m. Table 2
- the specific surface area of barium titanate or the pulverized ceramic raw material was measured as follows.
- X is a relative pressure (adsorption equilibrium pressure saturated vapor pressure)
- V is an amount of He absorbed at the relative pressure X (cm 3 / g)
- C is He 6 is a parameter showing a difference between heat of adsorption in the first layer and heat of adsorption in the second layer.
- the zirconia that is, the pulverizing medium
- the zirconia has a particle size of 400 times or less the average particle size of the starting material barium titanate. It is desirable to use one. It is desirable to use a medium having a particle diameter of preferably 200 m or less, more preferably 100 m or less, and even more preferably 50 im or less.
- the specific surface area of the powder after calcination is less than 0.5 of that before calcination, In other words, when the calcination temperature is high, agglomerated powder is easily formed. Capacitors made using such materials have poor DC bias characteristics. Therefore, it is desirable that the specific surface area of the powder after the calcination be 0.5 to 1 times that of the powder before the calcination.
- zirconia pole is used as the mixing medium and the pulverizing medium.
- any material that does not greatly change the composition of the obtained dielectric layer, such as alumina balls, may be used.
- the heat history should be as uniform as possible to suppress agglomeration and should be performed in a short time.
- the raw material of the dielectric layer composed mainly of barium titanate, M g O as the minor component, D y 2 ⁇ 3, was used like Eta theta 2_Rei 3, Ji Yun
- a raw material powder containing an acid barrier as a main component was used like Eta theta 2_Rei 3, Ji Yun
- the temperature of the water of the dispersion medium rises during the stirring process. If the temperature is too high, it is difficult to obtain a desired slurry. Therefore, the temperature of the mixture of water and the ceramic powder should be kept at 50 ° C or less, preferably at room temperature or less. Further, in the present embodiment, as shown in FIG. 1, a mixing tank having a stirring rod was used, but a container capable of mixing a medium such as zirconia pole and the raw material powder may be used. It is not necessary.
- the weight of the raw material powder after drying be 1.08 times or less, more preferably 1.05 times or less, of the weight of the raw material powder at the time of weighing.
- the thickness of the dielectric layer is set to 3.However, when the thickness of the dielectric layer is 3 to less than 1 m, the DC bias characteristic shows the same tendency depending on the particle size of the zirconia pole used. I understood.
- Embodiment 2
- the calcined powder is wet-mixed and dried in the same manner as in the samples No. 4D and 8D of the first embodiment.
- a binder and the like are mixed with the dried calcined powder to prepare a slurry for preparing a ceramic green sheet.
- an alcohol such as ethanol is mixed with the dried calcined powder so that the surface of the calcined powder particles is covered with the alcohol.
- n-butyl acetate as a solvent, benzyl butyl phthalate as a plasticizer, and polybierbutyral resin as a binder are mixed with the calcined powder.
- the surface of the calcined powder particles is first coated with alcohol and then mixed with a solvent, a plasticizer, and a binder, aggregation of the particles of the calcined powder can be suppressed.
- the amount of alcohol added is too large, a desired ceramic sheet cannot be obtained. Therefore, the amount of the alcohol to be added is such that the aggregation of the particles of the calcined powder can be suppressed and the surface thereof can be covered, and is smaller than the total amount of the binder, the solvent and the plasticizer.
- the above mixture is passed through a mixing tank 10 as shown in FIG. 1 to obtain a slurry having excellent dispersibility.
- the calcined powder is also used
- the particle size of zirconia pole is much smaller than before, so that the calcined powder will not be excessively ground due to excessive impact.
- the calcined powder used in the slurry for preparing the ceramic green sheet has a larger particle size than the starting material. Therefore, in the present embodiment, as in Embodiment 1, in order to appropriately pulverize the calcined powder, zirconiapole having a particle size equal to or larger than that used in mixing the starting materials should be used. Is desirable. However, the particle size is preferably 200 m or less.
- the mixing tank 10 be filled with spherical zirconia pole in a close-packed manner. At this time, the zirconia is theoretically occupying 74% of the internal volume of the mixing tank 10. Further, when the content of the zirconia is less than 60% of the internal volume of the mixing tank 10, mixing cannot be sufficiently performed, and the dispersibility deteriorates.
- the zirconium alcohol should occupy 60 to 74%, preferably 70 to 74% of the internal volume of the mixing tank 10.
- the rotation speed of the stirring rod 12 and the inflow speed of the mixture are controlled so that excessive force is not applied to the calcined powder.
- the calcined powder collides with the zirconia pole and is pulverized. Excessive pulverization can be suppressed, and a dielectric layer with less variation in crystal particle diameter can be effectively obtained.
- the slurry prepared as described above is coated on a support sheet such as a sheet of polyethylene terephthalate by a doctor blade method to form a ceramic sheet to be a dielectric layer.
- Samples No. 4D-1 to 4D-4 have the same milling conditions after mixing and calcination as Sample No. 4D, and samples No. 8D-1 to 4D-4.
- 8D-4 has the same milling conditions after mixing and calcining as sample No. 8D
- the particle size of zirconiapole when barium titanate having the same particle size is used, the smaller the particle size of zirconiapole, the better the DC bias characteristics.
- the particle size of zirconiapore is less than 400 times the average particle size of barium titanate. In that case, the effect is significant.
- the smaller the average particle size of barium titanate the smaller the variation, so that the DC bias characteristics of the obtained multilayer ceramic capacitor are improved.
- zirconium pole it is desirable to use a zirconium pole, that is, a medium having a particle diameter of 400 times or less the average particle diameter of barium titanate as a starting material. Specifically, it is desirable to use a small medium having a particle size of 200 m or less, preferably 100 m or less, and more preferably 50 m or less.
- the particle size and dispersion of parium titanate used as a starting material should be as close as possible to the particle size and dispersion of the raw material powder when producing ceramic green sheets. It is important to do so. Therefore, it is effective to consider the particle size of zirconia pole not only when mixing the starting materials, but also after mixing the slurry for preparing a ceramic green sheet after calcination.
- a multilayer ceramic capacitor having excellent DC bias characteristics can be provided.
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Ceramic Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Inorganic Chemistry (AREA)
- Ceramic Capacitors (AREA)
- Compositions Of Oxide Ceramics (AREA)
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/502,602 US7335328B2 (en) | 2002-10-28 | 2003-10-24 | Method for manufacturing multilayer ceramic capacitor |
DE60332087T DE60332087D1 (de) | 2002-10-28 | 2003-10-24 | Ramischen kondensators |
JP2004546483A JP4445392B2 (ja) | 2002-10-28 | 2003-10-24 | 積層セラミックコンデンサの製造方法 |
AU2003275665A AU2003275665A1 (en) | 2002-10-28 | 2003-10-24 | Method for manufacturing multilayer ceramic capacitor |
EP03758904A EP1460659B1 (en) | 2002-10-28 | 2003-10-24 | Method for manufacturing a multilayer ceramic capacitor |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2002-312447 | 2002-10-28 | ||
JP2002312447 | 2002-10-28 |
Publications (1)
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WO2004038744A1 true WO2004038744A1 (ja) | 2004-05-06 |
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ID=32171128
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PCT/JP2003/013668 WO2004038744A1 (ja) | 2002-10-28 | 2003-10-24 | 積層セラミックコンデンサの製造方法 |
Country Status (7)
Country | Link |
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US (1) | US7335328B2 (ja) |
EP (1) | EP1460659B1 (ja) |
JP (1) | JP4445392B2 (ja) |
CN (1) | CN100433210C (ja) |
AU (1) | AU2003275665A1 (ja) |
DE (1) | DE60332087D1 (ja) |
WO (1) | WO2004038744A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006056765A (ja) * | 2004-08-24 | 2006-03-02 | Matsushita Electric Ind Co Ltd | セラミック粉末ならびに積層セラミックコンデンサの製造方法 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09169564A (ja) * | 1995-12-20 | 1997-06-30 | Tokin Corp | 誘電体磁器組成物及びその製造方法 |
JPH1087372A (ja) * | 1996-09-09 | 1998-04-07 | Taiyo Yuden Co Ltd | セラミック材料粉末の製造方法 |
JPH10335171A (ja) * | 1997-06-03 | 1998-12-18 | Matsushita Electric Ind Co Ltd | セラミックスラリーの製造方法 |
JP2000203941A (ja) * | 1999-01-11 | 2000-07-25 | Tdk Corp | セラミックペ―ストの製造方法 |
JP2002226263A (ja) * | 2001-01-30 | 2002-08-14 | Kyocera Corp | 誘電体磁器および積層セラミックコンデンサ |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
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JP3295018B2 (ja) * | 1997-06-06 | 2002-06-24 | 太陽誘電株式会社 | チタン酸バリウム粉末の製造方法 |
WO2000043328A1 (de) * | 1999-01-20 | 2000-07-27 | Siemens Aktiengesellschaft | Wässrige keramische giessmasse, verfahren zur herstellung der giessmasse und verwendung der giessmasse |
JP3675264B2 (ja) * | 1999-12-03 | 2005-07-27 | 株式会社村田製作所 | セラミックスラリー、セラミックグリーンシート及び積層セラミック電子部品の製造方法 |
AU2003275664A1 (en) * | 2002-10-28 | 2004-05-13 | Matsushita Electric Industrial Co., Ltd. | Process for producing laminated ceramic capacitor |
-
2003
- 2003-10-24 DE DE60332087T patent/DE60332087D1/de not_active Expired - Lifetime
- 2003-10-24 JP JP2004546483A patent/JP4445392B2/ja not_active Expired - Lifetime
- 2003-10-24 CN CNB2003801000795A patent/CN100433210C/zh not_active Expired - Lifetime
- 2003-10-24 AU AU2003275665A patent/AU2003275665A1/en not_active Abandoned
- 2003-10-24 WO PCT/JP2003/013668 patent/WO2004038744A1/ja active Application Filing
- 2003-10-24 EP EP03758904A patent/EP1460659B1/en not_active Expired - Lifetime
- 2003-10-24 US US10/502,602 patent/US7335328B2/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09169564A (ja) * | 1995-12-20 | 1997-06-30 | Tokin Corp | 誘電体磁器組成物及びその製造方法 |
JPH1087372A (ja) * | 1996-09-09 | 1998-04-07 | Taiyo Yuden Co Ltd | セラミック材料粉末の製造方法 |
JPH10335171A (ja) * | 1997-06-03 | 1998-12-18 | Matsushita Electric Ind Co Ltd | セラミックスラリーの製造方法 |
JP2000203941A (ja) * | 1999-01-11 | 2000-07-25 | Tdk Corp | セラミックペ―ストの製造方法 |
JP2002226263A (ja) * | 2001-01-30 | 2002-08-14 | Kyocera Corp | 誘電体磁器および積層セラミックコンデンサ |
Non-Patent Citations (1)
Title |
---|
See also references of EP1460659A4 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006056765A (ja) * | 2004-08-24 | 2006-03-02 | Matsushita Electric Ind Co Ltd | セラミック粉末ならびに積層セラミックコンデンサの製造方法 |
Also Published As
Publication number | Publication date |
---|---|
JPWO2004038744A1 (ja) | 2006-02-23 |
EP1460659B1 (en) | 2010-04-14 |
CN1685455A (zh) | 2005-10-19 |
EP1460659A1 (en) | 2004-09-22 |
US20050116393A1 (en) | 2005-06-02 |
AU2003275665A1 (en) | 2004-05-13 |
CN100433210C (zh) | 2008-11-12 |
EP1460659A4 (en) | 2009-03-04 |
JP4445392B2 (ja) | 2010-04-07 |
US7335328B2 (en) | 2008-02-26 |
DE60332087D1 (de) | 2010-05-27 |
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