CN111499374A - Ceramic dielectric material for capacitor and preparation method thereof - Google Patents
Ceramic dielectric material for capacitor and preparation method thereof Download PDFInfo
- Publication number
- CN111499374A CN111499374A CN202010303305.5A CN202010303305A CN111499374A CN 111499374 A CN111499374 A CN 111499374A CN 202010303305 A CN202010303305 A CN 202010303305A CN 111499374 A CN111499374 A CN 111499374A
- Authority
- CN
- China
- Prior art keywords
- powder
- dielectric material
- ceramic dielectric
- temperature
- ceramic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/46—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on titanium oxides or titanates
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
- C04B2235/3208—Calcium oxide or oxide-forming salts thereof, e.g. lime
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
- C04B2235/3213—Strontium oxides or oxide-forming salts thereof
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3262—Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO
- C04B2235/3267—MnO2
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
- C04B2235/3272—Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3298—Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6562—Heating rate
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6567—Treatment time
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Ceramic Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Inorganic Insulating Materials (AREA)
Abstract
The invention relates to a ceramic dielectric material for a capacitor and a preparation method thereof, wherein the structural general formula of the ceramic dielectric material is aTiO2‑bSrO‑cBi2O3‑dFe2O3‑eCaO‑fMnO2The method for preparing the ceramic dielectric material comprises the steps of mixing and uniformly grinding raw material powder in a certain molar ratio to obtain a mixture, pre-burning the mixture, finely grinding the mixture to obtain pre-burned powder, further adding a binder into the pre-burned powder, granulating, carrying out compression molding to obtain a biscuit, finally carrying out binder removal and sintering to obtain the ceramic dielectric material, wherein the ceramic dielectric material has the characteristics of adjustable dielectric constant, small dielectric loss, small capacitance change rate and large high temperature limit value, can be used for ceramic capacitors and M L CC, and has low cost and good industrial prospect.
Description
Technical Field
The invention belongs to the technical field of electronic component ceramic materials, and relates to a ceramic dielectric material for a capacitor and a preparation method thereof.
Background
Ceramic capacitors are widely used in the fields of electric power, electronic equipment, and the like, and are continuously developing in the directions of miniaturization, large capacity, high voltage, high temperature, high frequency, and the like. Important parameters of ceramic capacitors include the rate of change of temperature capacity and the temperature range of use. According to EIA standard, the ceramic capacitors of X7R, X8R and X9R require that the temperature change rate | delta C/C25 | is less than or equal to +/-15% when the high temperature reaches 125 ℃, 150 ℃ and 200 ℃. While other electronic components in electronic devices, such as energy conversion devices in electromechanical actuators, are required to withstand higher operating temperatures.
Therefore, it is very important to develop a dielectric material for ceramic capacitor having a higher use temperature. Assuming that the capacitor electrode area is S and the dielectric material thickness is t, the capacitance value C of the capacitor and the relative dielectric constant of the dielectric material arerThe relationship of (1) is: c ═0 rS/d(0Is the vacuum permittivity). It follows that the change in relative permittivity with temperature directly determines the rate of change of the capacitance temperature of the capacitor.
In the prior art, ceramic dielectric materials used by a temperature-stable ceramic capacitor and a widely used multilayer ceramic capacitor (M L CC) are mainly classified into two types, one is a lead-containing dielectric material, and the other is a barium titanate-based core-shell structure material, because lead element is harmful to human beings and the environment, the barium titanate-based core-shell structure material is a main dielectric material of the temperature-stable ceramic capacitor and the multilayer ceramic capacitor (M L CC) based on environmental and health considerations, however, because pure barium titanate has phase change at-120 ℃, the capacitance stability is influenced, and the use of the pure barium titanate under a high-temperature condition is limited.
Disclosure of Invention
In view of the above problems, the present invention provides a ceramic dielectric material for capacitors and a method for preparing the same, and one of the objects is to provide a ceramic dielectric material for capacitors, which has a general structural formula of a TiO2-bSrO-cBi2O3-dFe2O3-eCaO-fMnO2Wherein a is more than or equal to 0.6, b +2c + e is 1, c is more than or equal to 0 and is more than or equal to d, e is more than or equal to 0, and f is more than or equal to 0 and is less than or equal to 0.05; the ceramic dielectric material has the characteristics of adjustable dielectric constant, small dielectric loss, small capacitance change rate and large high-temperature limit value. The second purpose of the method is to provide a preparation method of the ceramic dielectric material for the capacitor, which comprises the following steps: firstly, mixing raw material powder in a certain molar ratio and uniformly grinding to obtain a mixture; then the mixture is presintered and finely ground to prepare presintered powder; further, adding a binder into the pre-sintered powder, granulating, and performing compression molding to obtain a biscuit; finally, the biscuit is sintered after glue discharging to obtain the ceramic dielectric materialAnd (5) feeding. The preparation method of the ceramic dielectric material is not limited to the method, and similar or better performance can be produced by using a novel ceramic preparation technology such as a high-temperature co-firing technology.
In order to achieve the purpose, the invention adopts the following scheme:
a ceramic dielectric material for capacitor, the general formula of the ceramic dielectric material is aTiO2-bSrO-cBi2O3-dFe2O3-eCaO-fMnO2Wherein a is not less than 0.6, b +2c + e is 1, c is not less than 0 and not more than d, e is not less than 0 and not more than 0, and f is not less than 0.05. Bi element is introduced to improve the polarizability of a medium system; mn element is introduced to reduce the dielectric loss of the material; ca element is introduced to reduce the cost;
as a preferred technical scheme:
the ceramic dielectric material for the capacitor has the advantages that the dielectric constant of the ceramic dielectric material is adjustable within 215-1202 ℃ at 25 ℃, and the dielectric loss is less than 0.05.
The ceramic dielectric material for capacitor has a capacitance temperature change rate of |. DELTA.C/C25℃The highest temperature of less than or equal to plus or minus 15 percent is 120-215 ℃.
The ceramic dielectric material for the capacitor is machined to a required size, polished on the surface, covered with the electrode and welded with the lead wire to form the ceramic capacitor element.
The invention also provides a preparation method of the ceramic dielectric material for the capacitor, which comprises the following steps:
(1) mixing TiO with a certain molar ratio2Powder, powder A, and Bi2O3Powder of Fe2O3Powder, B powder and MnO2Mixing and grinding the powder uniformly to obtain a mixture; the grinding method is a wet ball grinding method; when wet ball milling is adopted, the mass ratio of materials to grinding balls to water (or alcohol) is 1: 2-4: 0.5-1, and the grinding time is 6-48 hours;
the A powder is SrO powder or SrCO3Powder; the B powder is CaCO3Powder or CaO powder;
the certain molar ratio is a: b: c: d: e: f; to avoid loss of Bi by volatilization, according to Bi2O3Molar amount of (a) of Bi is actually added2O3The amount of (b) can be 1-3% excess, preferably 1.5% excess;
(2) pre-burning the mixture and then finely grinding to prepare pre-burned powder;
the pre-sintering powder is further subjected to fine grinding, when the pre-sintering powder is subjected to fine grinding, the mass ratio of the pre-sintering powder to grinding balls to water (or alcohol) is 1: 2-4: 0.5-1, and the fine grinding time is 6-48 hours; the grinding balls can be iron balls, agate balls or zirconia balls and the like; after fine grinding, drying at 100-120 ℃, and sieving by a 40-mesh sieve;
(3) adding a binder into the pre-sintered powder, granulating, and performing compression molding to obtain a biscuit;
(4) removing binder and other organic substances from the biscuit, sintering, and naturally cooling to room temperature to obtain the product with the general formula of aTiO2-bSrO-cBi2O3-dFe2O3-eCaO-fMnO2The ceramic dielectric material of (1).
As a preferred technical scheme:
the preparation method of the ceramic dielectric material for the capacitor comprises the steps of preparing the SrO powder and the SrCO3Powder of Bi2O3Powder, CaCO3Powder, CaO powder, TiO2Powder of Fe2O3Powder and MnO2The purity of the powder is more than 99.0 percent.
In the above method for preparing a ceramic dielectric material for capacitors, the grinding and the fine grinding are both wet ball milling methods.
According to the preparation method of the ceramic dielectric material for the capacitor, the binder is polyvinyl alcohol (PVA), and the adding amount of the PVA is 4-5 wt% of the mass of the pre-sintered powder.
According to the preparation method of the ceramic dielectric material for the capacitor, the temperature rising rate of the pre-sintering is 2-3 ℃/min, the temperature is 700-800 ℃, and the heat preservation time is 3-6 h; the heating rate of the binder removal is 3-4 ℃/min, the temperature is 600-800 ℃, and the time is 2-4 h; the temperature rise rate of the sintering is 3-4 ℃/min, the temperature is 1100-1200 ℃, and the heat preservation time is 2-5 h; the pressure of the pressing forming is 100-500 MPa.
In the above method for preparing a ceramic dielectric material for capacitors, the sintering atmosphere is air.
The principle of the invention is as follows:
the raw materials with a certain molar ratio are mixed, and the dielectric constant of the prepared ceramic dielectric material can be adjusted through the proportional relation among the raw materials; in addition, MnO was added to the raw materials2The dielectric loss of the ceramic dielectric material can be adjusted to be smaller; the raw materials do not have phase change in the manufacturing process, so that the ceramic dielectric material has the advantages of small capacitance change rate, large high-temperature limit value and good temperature stability. The invention is not limited to the use of MnO only2The electric property can be adjusted, and the alloy can be used under the condition that the loss can be reduced by doping other transition metal ions and rare earth ions.
Advantageous effects
(1) The ceramic dielectric material for the capacitor has the advantages of adjustable dielectric constant, low dielectric loss and small temperature change rate, and can be used for ceramic capacitors and M L CC;
(2) the preparation method of the ceramic dielectric material for the capacitor, provided by the invention, can be used for sintering at a medium and low temperature, is environment-friendly, has a simple process and low cost, and has a good industrialization prospect.
Drawings
FIG. 1 is an XRD pattern of the ceramic dielectric materials in comparative examples 1 to 2 and examples 1 to 3;
FIG. 2 is a microscopic view of the ceramic dielectric material prepared in comparative example 1;
FIG. 3 is a microstructure diagram of the ceramic dielectric material prepared in example 1;
FIGS. 4 to 7 are dielectric thermograms of the ceramic dielectric materials of comparative examples 1 to 2, examples 1 and 3, in which the test frequencies were 1kHz, 10kHz, 100kHz and 1 MHz.
Detailed Description
The invention will be further illustrated with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.
Example 1
A preparation method of a ceramic dielectric material for a capacitor comprises the following steps:
(1) according to the mol ratio of 0.70:0.70:0.15:0.15:0.01 of TiO2Powder, SrO powder, Bi2O3Powder of Fe2O3Powder and MnO2Mixing the powder, uniformly grinding by adopting a wet ball grinding process, grinding for 24 hours according to the mass ratio of grinding balls to deionized water of 1:2:1, drying after grinding, and sieving by a 40-mesh sieve to obtain a mixture; wherein, TiO2Powder, SrO powder, Bi2O3Powder of Fe2O3Powder and MnO2The purity of the powder is more than 99.0 percent;
(2) pre-sintering the mixture, wherein the pre-sintering process comprises the following steps: raising the temperature to 800 ℃ at the temperature rise speed of 3 ℃/min, and preserving the heat for 3 hours to obtain presintering powder;
(3) finely grinding the pre-sintered powder in the step (2) for 48 hours according to the mass ratio of materials, namely grinding balls and deionized water, of 1:2:0.8, drying after fine grinding, and sieving with a 40-mesh sieve; adding 5 wt% of PVA into the pre-sintered powder for granulation, and performing dry pressing to form a biscuit with the diameter of 10mm and the thickness of about 1 mm;
(4) keeping the biscuit in the step (3) at 800 ℃ for 2h at the heating rate of 3 ℃/min in a sintering furnace, and removing organic substances in the biscuit; continuously heating to 1200 ℃ at the heating rate of 3 ℃/min for 3 hours, and sintering to obtain the ceramic dielectric material, wherein the chemical general formula of the ceramic dielectric material is aTiO2-bSrO-cBi2O3-dFe2O3-fMnO2Wherein a is 0.7, b is 0.7, c is 0.15, d is 0.15, and f is 0.01.
XRD test is carried out on the obtained ceramic dielectric material, and the test result is shown in figure 1, from which the ceramic dielectric material is in a cubic phase structure at room temperature, and no generation of a second phase is observed. The ceramic dielectric material is observed by a surface scanning electron microscope, as shown in fig. 3, the ceramic dielectric material has no abnormal grain growth, the material presents a compact microscopic microstructure, the grain boundary is clear, the grain size distribution is uniform, no obvious pores are generated, and the average grain size is about 1 μm.
Grinding the surface of the sintered ceramic dielectric material, cleaning, drying, performing screen printing of silver paste, drying, putting into an electric furnace for silver firing, and keeping the temperature of 600 ℃ for 30 minutes under the silver firing condition to obtain the ceramic capacitor; the ceramic capacitor was subjected to a dielectric temperature spectrum test, and the results are shown in FIG. 6, the dielectric constant of the ceramic capacitor is stable with the temperature and frequency, and the dielectric properties of the ceramic capacitor at 1kHz are shown in Table 1.
Example 2
A preparation method of a ceramic dielectric material for a capacitor comprises the following steps:
(1) according to the mol ratio of 0.80:0.56:0.10:0.10:0.24 of TiO2Powder, SrO powder, Bi2O3Powder of Fe2O3Mixing the powder and CaO powder, uniformly grinding by adopting a wet ball grinding process, grinding for 24 hours according to the mass ratio of grinding balls to deionized water of 1:2:1, drying after grinding, and sieving by a 40-mesh sieve to obtain a mixture; wherein, SrO powder and TiO2Powder of Bi2O3Powder of Fe2O3The purities of the powder and the CaO powder are both more than 99.0 percent;
(2) pre-sintering the mixture, wherein the pre-sintering process comprises the following steps: raising the temperature to 800 ℃ at the temperature rise speed of 3 ℃/min, and preserving the heat for 3 hours to obtain presintering powder;
(3) finely grinding the pre-sintered powder in the step (2) for 48 hours according to the mass ratio of materials, namely grinding balls and deionized water, of 1:2:0.8, drying after fine grinding, and sieving with a 40-mesh sieve; adding 5 wt% of PVA into the pre-sintered powder for granulation, and performing dry pressing to form a biscuit with the diameter of 10mm and the thickness of about 1 mm;
(4) keeping the biscuit in the step (3) at 800 ℃ for 2h at the heating rate of 3 ℃/min in a sintering furnace, and removing organic substances in the biscuit; continuously heating to 1200 ℃ at the heating rate of 3 ℃/minuteSintering at 3 hours to obtain the ceramic dielectric material with the chemical general formula of aTiO2-bSrO-cBi2O3-dFe2O3-eCaO, wherein a is 0.80, b is 0.56, c is 0.10, d is 0.10, and e is 0.24.
XRD test is carried out on the obtained ceramic dielectric material, and the test result is shown in figure 1, from which the ceramic dielectric material is in a cubic phase structure at room temperature, and no generation of a second phase is observed.
Grinding the surface of the sintered ceramic dielectric material, cleaning, drying, performing screen printing of silver paste, drying, putting into an electric furnace for silver firing, and keeping the temperature of 600 ℃ for 30 minutes under the silver firing condition to obtain the ceramic capacitor; the ceramic capacitor is tested by a dielectric temperature spectrum, and the dielectric constant is stable along with the change of temperature and frequency. The dielectric properties of the ceramic capacitor at 1kHz are shown in Table 1.
Example 3
A preparation method of a ceramic dielectric material for a capacitor comprises the following steps:
(1) according to the mol ratio of 0.80:0.40:0.10:0.10:0.40 of TiO2Powder, SrO powder, Bi2O3Powder of Fe2O3Mixing the powder with CaO powder, uniformly grinding by adopting a wet ball grinding process, grinding for 24 hours according to the mass ratio of grinding balls to deionized water of 1:2:1, drying after grinding, and sieving by a 40-mesh sieve to obtain a mixture; wherein, SrO powder and TiO2Powder of Bi2O3Powder of Fe2O3The purities of the powder and the CaO powder are both more than 99.0 percent;
(2) pre-sintering the mixture, wherein the pre-sintering process comprises the following steps: raising the temperature to 800 ℃ at the temperature rise speed of 3 ℃/min, and preserving the heat for 3 hours to obtain presintering powder;
(3) finely grinding the pre-sintered powder in the step (2) for 48 hours according to the mass ratio of materials, namely grinding balls and deionized water, of 1:2:0.8, drying after fine grinding, and sieving with a 40-mesh sieve; adding 5 wt% of PVA into the pre-sintered powder for granulation, and performing dry pressing to form a biscuit with the diameter of 10mm and the thickness of about 1 mm;
(4) the biscuit in the step (3) is put in a sintering furnace at the temperature of 3 ℃/minKeeping the temperature for 2h when the temperature rate reaches 800 ℃, and removing organic substances in the biscuit; continuously heating to 1200 ℃ at the heating rate of 3 ℃/min for 3 hours, and sintering to obtain the ceramic dielectric material, wherein the chemical general formula of the ceramic dielectric material is aTiO2-bSrO-cBi2O3-dFe2O3-eCaO, wherein a is 0.80, b is 0.40, c is 0.10, d is 0.10, and e is 0.40.
XRD test is carried out on the obtained ceramic dielectric material, and the test result is shown in figure 1, from which the ceramic dielectric material is in a cubic phase structure at room temperature, and no generation of a second phase is observed.
Grinding the surface of the sintered ceramic dielectric material, cleaning, drying, performing screen printing of silver paste, drying, putting into an electric furnace for silver firing, and keeping the temperature of 600 ℃ for 30 minutes under the silver firing condition to obtain a ceramic capacitor; the ceramic capacitor was subjected to a dielectric temperature spectrum test, and the result is shown in fig. 7, in which the dielectric constant was stable with changes in temperature and frequency.
Rate of change of temperature | Δ C/C25℃The highest temperature of | ≦ 15% is 1kHz, 10kHz, 100kHz and 1MHz are 215 ℃, 227 ℃, 282 ℃ and 321 ℃ respectively.
Comparative example 1
The preparation method of the ceramic dielectric material for the capacitor basically comprises the following steps of the same steps as the example 1, and the difference is only that the raw materials adopted in the step (1) are different:
SrO powder and TiO powder with the molar ratio of 0.70:0.70:0.15:0.152Powder of Bi2O3Powder and Fe2O3Mixing powders of SrO powder and TiO2Powder of Bi2O3Powder and Fe2O3The purity of the powder is more than 99.0 percent;
the chemical general formula of the prepared ceramic dielectric material is aTiO2-bSrO-cBi2O3-dFe2O3Wherein a is 0.70, b is 0.70, c is 0.15, and d is 0.15.
The obtained ceramic dielectric material was subjected to XRD measurement, and the measurement results are shown in fig. 1, from which it can be seen that the ceramic dielectric material has a cubic phase structure at room temperature, and no generation of a second phase was observed. The surface scanning electron microscope observation of the ceramic dielectric material is carried out, and as shown in fig. 2, it is known from fig. 2 that abnormal grain growth occurs in the ceramic dielectric material.
Grinding the surface of the prepared ceramic dielectric material, cleaning, drying, performing screen printing of silver paste, drying, putting into an electric furnace for silver firing, and keeping the temperature of 600 ℃ for 30 minutes under the silver firing condition to obtain a ceramic capacitor; the ceramic capacitor was subjected to a dielectric temperature spectrum test, and the results are shown in FIG. 4, in which the dielectric constant gradually increased with increasing temperature and the dielectric constant significantly decreased with increasing frequency.
Comparative example 2
The preparation method of the ceramic dielectric material for the capacitor basically comprises the following steps of the same steps as the example 1, and the difference is only that the raw materials adopted in the step (1) are different:
TiO with a molar ratio of 0.8:0.8:0.1:0.12Powder, SrO powder, Bi2O3Powder and Fe2O3Mixing powders of SrO powder and TiO2Powder of Bi2O3Powder and Fe2O3The purity of the powder is more than 99.0 percent;
the chemical general formula of the prepared ceramic dielectric material is aTiO2-bSrO-cBi2O3-dFe2O3Wherein, a is 0.80, b is 0.80, c is 0.10, and d is 0.10.
XRD test is carried out on the obtained ceramic dielectric material, and the test result is shown in figure 1, from which the ceramic dielectric material is in a cubic phase structure at room temperature, and no generation of a second phase is observed.
Grinding the surface of the sintered ceramic dielectric material, cleaning, drying, performing screen printing of silver paste, drying, putting into an electric furnace for silver firing, and keeping the temperature of 600 ℃ for 30 minutes under the silver firing condition to obtain the ceramic capacitor; the ceramic capacitor was subjected to a dielectric temperature spectrum test, and the results are shown in FIG. 5, in which the dielectric constant gradually increased with an increase in temperature and the dielectric constant significantly decreased with an increase in frequency.
TABLE 1 dielectric properties at 1kHz for the comparative examples 1 to 2 and the ceramic capacitors of examples 1 to 3
As can be seen from Table 1, the ceramic capacitor dielectric materials prepared in examples 1, 2 and 3 have good temperature stability and capacitance change rate | Delta C/C at very high temperature25℃Less than or equal to +/-15 percent, the requirement of the embodiment 1 is better than that of X8R, the requirement of the embodiment 2 is met by X7R, the requirement of the embodiment 3 is better than that of X9R, and the maximum temperature of the temperature change rate of less than 15 percent is 125 ℃, 150 ℃ and 200 ℃ respectively by X8R, X7R and X9R.
Comparing comparative examples 1 and 2 with example 1, it can be seen that the addition of Mn eliminates abnormal grain growth, reduces dielectric loss, and improves temperature stability.
Example 4
A preparation method of a ceramic dielectric material for a capacitor comprises the following steps:
(1) TiO with the theoretical molar ratio of 0.8:0.24:0.10:0.10:0.562Powder, SrO powder, Bi2O3Powder of Fe2O3Powder, and CaCO3Mixing and grinding the powder uniformly to obtain a mixture; grinding by adopting a wet ball grinding method, wherein the grinding time is 6h, and the mass ratio of materials to grinding balls to water is 1:3: 1; wherein, in order to avoid the loss of Bi volatilization, Bi is actually added according to the molar weight (theoretical calculation value) of Bi2O32O3The amount of (A) is 1% excess; and SrO powder and Bi2O3Powder, CaCO3Powder, TiO2Powder and Fe2O3The purity of the powder is 99.0%;
(2) pre-burning the mixture and then finely grinding to prepare pre-burned powder; wherein the temperature rising rate of the pre-sintering is 2 ℃/min, the temperature is 700 ℃, and the time is 6 h; finely grinding the pre-sintered powder by adopting a wet ball grinding method, wherein the mass ratio of the pre-sintered powder to grinding balls to water is 1:3:1, and the fine grinding time is 6 hours; the grinding ball can be zirconia ball; fine grinding, drying at 100 ℃, and sieving with a 40-mesh sieve;
(3) adding 4 wt% of polyvinyl alcohol into the presintered powder, granulating, and performing compression molding under the pressure of 200MPa to obtain a biscuit;
(4) removing glue from the biscuit (the heating rate of the glue removal is 4 ℃/min, the temperature is 600 ℃ and the time is 4h), sintering the biscuit in the air atmosphere (the heating rate of the sintering is 4 ℃/min, the temperature is 1100 ℃ and the time is 5h), and naturally cooling the biscuit to room temperature to obtain the ceramic dielectric material, wherein the chemical general formula of the ceramic dielectric material is aTiO2-bSrO-cBi2O3-dFe2O3-eCaO, wherein a is 0.80, b is 0.24, c is 0.10, d is 0.10, and e is 0.56.
The dielectric constant of the ceramic dielectric material is 282 and the dielectric loss is 0.005 at 25 ℃. The capacitance change rate of the ceramic dielectric material meets the condition that the highest temperature of | < delta > C/C25 | < +/-15% is 188 ℃. Ceramic dielectric materials may be used for ceramic capacitor elements.
Example 5
A preparation method of a ceramic dielectric material for a capacitor comprises the following steps:
(1) TiO with the theoretical molar ratio of 0.9:0.90:0.05:0.05:0.012Powder, SrO powder, Bi2O3Powder of Fe2O3Powder and MnO2Mixing and grinding the powder uniformly to obtain a mixture; grinding by adopting a wet ball grinding method, wherein the grinding time is 6h, and the mass ratio of materials to grinding balls to water is 1:3: 1; wherein, in order to avoid the loss of Bi volatilization, according to Bi2O3Molar amount of (theoretical calculation), Bi is actually added2O3The amount of (A) is 1% excess; and SrO powder and Bi2O3Powder, MnO2Powder, TiO2Powder and Fe2O3The purity of the powder is 99.0%;
(2) pre-burning the mixture and then finely grinding to prepare pre-burned powder; wherein the temperature rising rate of the pre-sintering is 2 ℃/min, the temperature is 700 ℃, and the time is 6 h; finely grinding the pre-sintered powder by adopting a wet ball grinding method, wherein the mass ratio of the pre-sintered powder to grinding balls to water is 1:3:1, and the fine grinding time is 6 hours; the grinding ball can be zirconia ball; fine grinding, drying at 100 ℃, and sieving with a 40-mesh sieve;
(3) adding 4 wt% of polyvinyl alcohol into the presintered powder, granulating, and performing compression molding under the pressure of 200MPa to obtain a biscuit;
(4) removing glue from the biscuit (the heating rate of the glue removal is 4 ℃/min, the temperature is 600 ℃ and the time is 4h), sintering the biscuit in the air atmosphere (the heating rate of the sintering is 4 ℃/min, the temperature is 1100 ℃ and the time is 5h), and naturally cooling the biscuit to room temperature to obtain the ceramic dielectric material, wherein the chemical general formula of the ceramic dielectric material is aTiO2-bSrO-cBi2O3-dFe2O3-fMnO2Wherein a is 0.90, b is 0.90, c is 0.05, d is 0.05, and f is 0.01.
The dielectric constant of the ceramic dielectric material is 215 at 25 ℃, and the dielectric loss is 0.01. The capacitance change rate of the ceramic dielectric material meets the requirement that the highest temperature of | < delta > C/C25 | < +/-15% is 139 ℃. Ceramic dielectric materials may be used for ceramic capacitor elements.
Claims (10)
1. A ceramic dielectric material for capacitors, characterized in that: the general formula of the ceramic dielectric material is
aTiO2-bSrO-cBi2O3-dFe2O3-eCaO-fMnO2Wherein a is not less than 0.6, b +2c + e is 1, c is not less than 0 and not more than d, e is not less than 0 and not more than 0, and f is not less than 0.05.
2. The ceramic dielectric material for capacitors as claimed in claim 1, wherein the dielectric constant of the ceramic dielectric material is 215 to 1202 at 25 ℃ and the dielectric loss is less than 0.05.
3. The ceramic dielectric material for capacitors as claimed in claim 1, wherein the ceramic dielectric material has a capacitance temperature change rate of | Δ C/C25℃The highest temperature of less than or equal to plus or minus 15 percent is 120-215 ℃.
4. The ceramic dielectric material for capacitors as claimed in claim 1, wherein the ceramic dielectric material is used for a ceramic capacitor element after being machined.
5. A preparation method of a ceramic dielectric material for a capacitor is characterized by comprising the following steps:
(1) mixing TiO with a certain molar ratio2Powder, powder A, and Bi2O3Powder of Fe2O3Powder, B powder and MnO2Mixing and grinding the powder uniformly to obtain a mixture;
the A powder is SrO powder or SrCO3Powder; the B powder is CaCO3Powder or CaO powder;
the certain molar ratio is a: b: c: d: e: f;
(2) pre-burning the mixture and then finely grinding to prepare pre-burned powder;
(3) adding a binder into the pre-sintered powder, granulating, and performing compression molding to obtain a biscuit;
(4) the biscuit is sintered after binder removal to obtain the general formula aTiO2-bSrO-cBi2O3-dFe2O3-eCaO-fMnO2The ceramic dielectric material of (1).
6. The method of claim 4 wherein said SrO powder and SrCO are mixed to form a ceramic dielectric material3Powder of Bi2O3Powder, CaCO3Powder, CaO powder, TiO2Powder of Fe2O3Powder and MnO2The purity of the powder is more than 99.0 percent.
7. The method of claim 4, wherein the grinding and the fine grinding are performed by wet ball milling.
8. The method for preparing the ceramic dielectric material for the capacitor as claimed in claim 4, wherein the binder is polyvinyl alcohol, and the addition amount is 4-5 wt% of the mass of the pre-sintered powder.
9. The preparation method of the ceramic dielectric material for the capacitor as claimed in claim 4, wherein the pre-sintering is performed at a temperature rise rate of 2-3 ℃/min, a temperature of 700-800 ℃ and a holding time of 3-6 h; the heating rate of the binder removal is 3-4 ℃/min, the temperature is 600-800 ℃, and the time is 2-4 h; the temperature rise rate of the sintering is 3-4 ℃/min, the temperature is 1100-1200 ℃, and the heat preservation time is 2-5 h.
10. The method of claim 4, wherein the sintering atmosphere is air.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010303305.5A CN111499374B (en) | 2020-04-17 | 2020-04-17 | Ceramic dielectric material for capacitor and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010303305.5A CN111499374B (en) | 2020-04-17 | 2020-04-17 | Ceramic dielectric material for capacitor and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111499374A true CN111499374A (en) | 2020-08-07 |
| CN111499374B CN111499374B (en) | 2022-08-19 |
Family
ID=71874371
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010303305.5A Active CN111499374B (en) | 2020-04-17 | 2020-04-17 | Ceramic dielectric material for capacitor and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111499374B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1148724A (en) * | 1995-06-06 | 1997-04-30 | 株式会社村田制作所 | Monolithic ceramic capacitor and production method thereof |
| EP1382588A1 (en) * | 2002-07-16 | 2004-01-21 | Denso Corporation | Piezoelectric ceramic composition and method of production of same, piezoelectric element, and dielectric element |
| CN101786864A (en) * | 2009-12-22 | 2010-07-28 | 广东风华高新科技股份有限公司 | Ceramic dielectric material matched with nickel inner electrode and production method of capacitor produced by ceramic dielectric material |
| US20100308692A1 (en) * | 2009-06-08 | 2010-12-09 | Fujifilm Corporation | Piezoelectric device, piezoelectric actuator having the same, liquid discharge apparatus, and power generating apparatus |
| CN103387381A (en) * | 2013-07-03 | 2013-11-13 | 上海工程技术大学 | Medium-high-temperature NTC thermistor material, preparation method and application |
| US20150236243A1 (en) * | 2014-01-20 | 2015-08-20 | Seiko Epson Corporation | Piezoelectric element, liquid ejecting head, and sensor |
| CN106165038A (en) * | 2014-02-21 | 2016-11-23 | 赛飞尔科技有限公司(现诺尔斯(英国)有限公司) | Dielectric substance and include the capacitor of dielectric substance |
| CN107056276A (en) * | 2017-03-28 | 2017-08-18 | 清华大学 | Bismuth ferrite based dielectric film for high density energy storage and its preparation method and application |
| CN109003821A (en) * | 2018-08-14 | 2018-12-14 | 东北大学 | A kind of ultra-high dielectric coefficient composite material, preparation method and application |
| CN110511018A (en) * | 2019-08-13 | 2019-11-29 | 华南师范大学 | A kind of high energy density ceramic capacitor dielectric and preparation method thereof |
-
2020
- 2020-04-17 CN CN202010303305.5A patent/CN111499374B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1148724A (en) * | 1995-06-06 | 1997-04-30 | 株式会社村田制作所 | Monolithic ceramic capacitor and production method thereof |
| EP1382588A1 (en) * | 2002-07-16 | 2004-01-21 | Denso Corporation | Piezoelectric ceramic composition and method of production of same, piezoelectric element, and dielectric element |
| US20100308692A1 (en) * | 2009-06-08 | 2010-12-09 | Fujifilm Corporation | Piezoelectric device, piezoelectric actuator having the same, liquid discharge apparatus, and power generating apparatus |
| CN101786864A (en) * | 2009-12-22 | 2010-07-28 | 广东风华高新科技股份有限公司 | Ceramic dielectric material matched with nickel inner electrode and production method of capacitor produced by ceramic dielectric material |
| CN103387381A (en) * | 2013-07-03 | 2013-11-13 | 上海工程技术大学 | Medium-high-temperature NTC thermistor material, preparation method and application |
| US20150236243A1 (en) * | 2014-01-20 | 2015-08-20 | Seiko Epson Corporation | Piezoelectric element, liquid ejecting head, and sensor |
| CN106165038A (en) * | 2014-02-21 | 2016-11-23 | 赛飞尔科技有限公司(现诺尔斯(英国)有限公司) | Dielectric substance and include the capacitor of dielectric substance |
| CN107056276A (en) * | 2017-03-28 | 2017-08-18 | 清华大学 | Bismuth ferrite based dielectric film for high density energy storage and its preparation method and application |
| CN109003821A (en) * | 2018-08-14 | 2018-12-14 | 东北大学 | A kind of ultra-high dielectric coefficient composite material, preparation method and application |
| CN110511018A (en) * | 2019-08-13 | 2019-11-29 | 华南师范大学 | A kind of high energy density ceramic capacitor dielectric and preparation method thereof |
Non-Patent Citations (6)
| Title |
|---|
| HAO PAN: "BiFeO3-SrTiO3 thin film as a new lead-free relaxorferroelectric capacitor with ultrahigh energy storage performance", 《JOURNAL OF MATERIALS CHEMISTRY A》 * |
| HONGBO LIU: "Structural, dielectric, and magnetic properties of BiFeO3-SrTiO3 solid solution ceramics", 《FERROELECTRICS》 * |
| JUAN LIU: "Effect of (Sr0.7Ca0.3)TiO3-substitution on structure,dielectric,ferroelectric,and magnetic properties of BiFeO3 ceramics", 《JOURNAL OF APPLIED PHYSICS》 * |
| LISONG LI: "Structural evolution and dielectric response of (1-x)BiFeO3-xSrTiO3 Ceramics", 《CERAMICS INTERNATIONAL》 * |
| NAOYUKI ITOH: "Effects of SrTiO3 content and Mn doping on dielectric and magnetic properties of BiFeO3-SrTiO3 Ceramics", 《JOURNAL OF THE CERAMIC SOCIETY OF JAPAN》 * |
| YUPING REN: "Tuning of electric and magnetic properties of BiFeO3-SrTiO3 solid solution ceramics by site-specific doping of Mn", 《JOURNAL OF ALLOYS AND COMPOUNDS》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111499374B (en) | 2022-08-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111763082B (en) | Barium strontium titanate-based dielectric ceramic material and preparation method and application thereof | |
| CN109133915B (en) | Barium titanate-based dielectric material with high energy storage capacity and preparation method thereof | |
| CN109354492B (en) | Bismuth-based lead-free high-energy-density ceramic material and preparation method thereof | |
| CN101549997A (en) | Dielectric ceramic composition and an electronic component | |
| KR20120075347A (en) | Dielectric ceramic composition and electronic component | |
| CN111410530B (en) | Anti-reduction BaTiO3Base medium ceramic and preparation method thereof | |
| CN107512906A (en) | A kind of anti-reduction X9R type ceramic capacitor dielectric materials and preparation method thereof | |
| EP3059748A1 (en) | All-solid-state capacitor | |
| CN114230335B (en) | BaTiO with giant dielectric constant, low loss and high resistivity 3 Fine crystal ceramic and its prepn | |
| CN108863348A (en) | A kind of dielectric ceramic material and preparation method thereof of ultra-wide temperature stability | |
| CN100378032C (en) | Barium phthalate base ceramic capacity medium and preparation process thereof | |
| CN108218423A (en) | A kind of X8R types ceramic capacitor dielectric material and preparation method thereof | |
| CN105399405B (en) | A kind of low dielectric microwave ferroelectric ceramics and preparation method thereof | |
| CN108863349A (en) | A kind of barium titanate-based lead-free height Jie temperature-stable ceramic material and preparation method thereof | |
| CN112341192B (en) | High-energy-storage-density sodium bismuth titanate-based lead-free dielectric material and preparation method thereof | |
| CN116768626B (en) | PbNb (PbNb) material 2 O 6 Base piezoelectric ceramic material and preparation method thereof | |
| CN111233464B (en) | Anti-ferroelectric composite ceramic material working in paraelectric phase and high in energy storage and preparation method thereof | |
| US11094463B2 (en) | Method for manufacturing spherical ceramic-glass nanocomposite dielectrics for multilayer ceramic capacitor applications | |
| CN109320236B (en) | Composite material with high energy storage density and charge-discharge performance and preparation method thereof | |
| CN107226696A (en) | X7R types BaTiO3Based capacitor ceramic material and preparation method thereof | |
| JP4511323B2 (en) | Multilayer ceramic capacitor and manufacturing method thereof | |
| CN111499374B (en) | Ceramic dielectric material for capacitor and preparation method thereof | |
| CN110304916B (en) | Anti-reduction BaTiO3Base medium ceramic and preparation method thereof | |
| CN108516827B (en) | Lead-free ceramic material with high dielectric energy storage density and high energy storage efficiency and preparation method thereof | |
| CN109180177A (en) | A kind of X9R type medium material for multilayer ceramic capacitors and its preparation method and application |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |