BCT-based dielectric material, multilayer ceramic capacitor and preparation method

Abstract

The invention discloses a BCT-based dielectric material, a multilayer ceramic capacitor and a preparation method. The composition expression formula of the dielectric material is (Ba1-xCax) (Ti1-yCay) O3-R2O3-MgO-MnO2-BaO-SiO2, and the dielectric material has the following structural formula as shown in the specification, x and y are mole fractions, x is greater than or equal to 0.01 and less than or equal to 0.08, and y is greater than or equal to 0.01 and less than or equal to The molar content of each component is as follows: 100% of (Ba1-xCax) (Ti1-yCay) O3, 0.3 to 3% of R2O3, 0.1 to 3% of MgO, 0.1 to 5% of MnO2, 0.1 to 2% of BaO and 0.1 to 2% of SiO2; and R2O3 is rare earth element oxide. The dielectric material can meet the requirements of MLCCs with different sizes, can improve the bias characteristic of the MLCCs, and improves the DC breakdown resistance and insulation aging resistance of the MLCCs.

Description

Technical Field

[0001] The present invention belongs to the technical field of capacitor dielectric materials, and in particular, relates to a BCT-based dielectric material, a multilayer ceramic capacitor and a preparation method thereof. Background Art

[0002] As a key passive component in the composition of electronic circuits, multilayer ceramic capacitors (MLCC) are widely used in communication equipment, automotive electronics, 5G communication base stations, aerospace and other fields due to their advantages such as small size, high capacitance and high reliability. With the continuous innovation and breakthroughs in the electronics industry, the requirements for components in electronic circuits are getting higher and higher, and miniaturization, high performance, high breakdown voltage and high reliability have become their development trend. For example, the rapid development of electric vehicles in recent years has driven the upgrade of the entire electrical system, especially the continuous breakthroughs in advanced safety driving assistance systems and battery energy systems. Greater power usage requires multilayer ceramic capacitors with higher voltage resistance and higher reliability to ensure the stable operation of electronic circuits.

[0003] At present, research on large-capacity MLCC and its dielectric materials at home and abroad is mostly focused on the barium titanate (BaTiO3, BT) system. After being prepared into capacitors, their bias characteristics and voltage resistance cannot meet the requirements. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a BCT-based dielectric material, a multilayer ceramic capacitor and a preparation method. The BCT-based dielectric material of the present invention can meet the needs of MLCCs of different sizes, improve the bias characteristics of multilayer ceramic capacitors, and enhance their DC breakdown resistance and insulation aging characteristics.

[0005] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0006] In one aspect, the present invention provides a BCT-based dielectric material, the composition expression of which is (Ba 1-x Ca x )(Ti 1-y Ca y )O3-R2O3-MgO-MnO2-BaO-SiO2, among which (Ba 1-x Ca x )(Ti 1-y Ca y )O3 is the matrix, R2O3-MgO-MnO2-BaO-SiO2 is the doping coating material; in the composition expression, x and y are molar fractions and meet the following conditions: 0.01≤x≤0.08, 0.01≤y≤0.05; the molar contents of the matrix and the doping coating material are as follows: (Ba 1-xCa x )(Ti 1-y Ca y )O3100mol%, R2O3 0.3-3mol%, MgO 0.1-3mol%, MnO2 0.1-5mol%, BaO 0.1-2mol%, SiO2 0.1-2mol%; wherein R2O3 is a rare earth element oxide, which is at least one of Y2O3, Ho2O3, Dy2O3, and Yb2O3; the (Ba 1-x Ca x )(Ti 1-y Ca y )The particle size of the O3 matrix is ​​80~250nm.

[0007] Preferably, the molar contents of the doping coating material are as follows: R2O3 0.7-2.1 mol%, MgO 1-2.5 mol%, MnO2 1-3.5 mol%, BaO 0.5-1.5 mol%, SiO2 0.5-1.5 mol%.

[0008] Another aspect of the present invention provides a method for preparing a BCT-based dielectric material, which comprises the following steps:

[0009] (1) will (Ba 1-x Ca x )(Ti 1-y Ca y ) O3 powder is mixed with a dispersion medium, and after ball milling and dispersion, a suspension of BCT matrix material is obtained;

[0010] (2) dissolving soluble metal salts of coating elements in deionized water according to molar fractions to obtain coating element metal salt solutions; the coating elements include R, Mg, Mn and Ba;

[0011] (3) adding the coating element metal salt solution and silica sol dropwise to the suspension of the BCT matrix material obtained in step (1), stirring and mixing evenly to prepare a preliminary slurry;

[0012] (4) adjusting the pH of the preliminary slurry to 6-10, allowing the coated elements to gradually precipitate, and aging for 1-2 hours to obtain a suspension of BCT-based dielectric material particles with a uniform surface coating;

[0013] (5) The BCT-based dielectric material particle suspension is granulated and dried, and then sintered to obtain a dielectric material powder.

[0014] Furthermore, the preparation process of the silica sol is: silicon alkoxide is uniformly mixed with ethanol, acetic acid and deionized water in a certain volume ratio to obtain the silica sol.

[0015] Furthermore, in step (4), aqueous ammonia is used to adjust the pH of the preliminary slurry.

[0016] Furthermore, the sintering temperature in step (5) is 300-600° C., and the sintering time is 2-8 hours.

[0017] The present invention also provides a multilayer ceramic capacitor, the dielectric material of which adopts the BCT-based dielectric material mentioned above.

[0018] The present invention further provides a method for preparing a multilayer ceramic capacitor, specifically comprising: adding a dispersant to a BCT-based dielectric material powder, dispersing it in a solvent, adding a binder after uniform dispersion, mixing and ball milling, and then performing cast drying to obtain a raw film strip of a certain thickness, and then performing electrode printing, lamination, equalizing pressing, cutting, debinding, sintering, chamfering, and capping processes to obtain a base metal inner electrode multilayer ceramic capacitor.

[0019] Furthermore, in the preparation method, the process conditions for debinding are: heating to 200-300° C. at a heating rate of 0.1-1° C. / min and keeping the temperature for 40-60 hours.

[0020] Furthermore, in the preparation method, the sintering is divided into two stages: reducing atmosphere sintering and reoxidation sintering; the conditions for reducing atmosphere sintering are: heating to 1100-1300°C at a heating rate of 5-40°C / min and keeping the temperature for 1-3h, and the oxygen partial pressure in this stage is 10 -8 ~10 -13 atm; the reoxidation sintering conditions are: cooling to 800-1100°C at a cooling rate of 5-20°C / min and keeping warm for 3-8h. The oxygen partial pressure at this stage is 10 -3 ~10 -5 atm.

[0021] Furthermore, the adhesive is PVB.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention uses a chemical coating method to prepare a BCT-based anti-reduction dielectric material, with a grain size range of 80 to 250nm, a use temperature of -55 to 125°C and -55 to 150°C, and is suitable for X7R / X8S / X8R MLCCs of different specifications and models. The dielectric materials of the present invention with different grain sizes can meet the needs of MLCCs of different sizes; the room temperature dielectric constant of the dielectric material of the present invention can reach 1500 to 2800, the capacitance-temperature change rate is ≤±22%, and the room temperature dielectric loss is ≤1.5%, which can meet the needs of MLCCs of different capacities; the present invention can meet the needs of high-voltage and high-reliability MLCCs through element doping and core-shell structure regulation.

[0024] The barium calcium titanate (BCT) system used in the present invention has a higher resistance than the barium titanate system dielectric material, and the room temperature resistivity is ≥10 12 (Ω·cm), and after being prepared into a capacitor, its bias characteristics and withstand voltage are greatly improved; at the same time, compared with the sodium bismuth titanate system, the barium calcium titanate (BCT) system dielectric material of the present invention satisfies the sintering in a reducing atmosphere, fully meets the requirements of base metal inner electrode multilayer ceramic capacitors, and can greatly reduce the production cost of capacitors.

[0025] The capacitor of the present invention adopts a BCT-based anti-reduction dielectric material and has excellent withstand voltage characteristics and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a metallographic micrograph of the end surface of the X8S type BME-MLCC in Example 3 of the present invention.

[0027] Figure 2 This is a metallographic micrograph of the long axis cross section of the X8S type BME-MLCC in Example 3 of the present invention.

[0028] Figure 3 This is a SEM image of the X8S type BME-MLCC dielectric material grains in Example 3 of the present invention.

[0029] Figure 4 This is a graph showing the relationship between the X8S type BME-MLCC capacitor and temperature in Example 3 of the present invention. DETAILED DESCRIPTION

[0030] The technical solutions in the present invention will be described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The present invention provides a BCT-based dielectric material, the composition expression of the dielectric material is (Ba 1-x Ca x )(Ti 1-y Ca y )O3-R2O3-MgO-MnO2-BaO-SiO2, among which (Ba 1-x Ca x )(Ti 1-y Ca y)O3 is the matrix, R2O3-MgO-MnO2-BaO-SiO2 is the doping coating material; in the composition expression, x and y are molar fractions and meet the following conditions: 0.01≤x≤0.08, 0.01≤y≤0.05; the molar contents of the matrix and the doping coating material are as follows: (Ba 1-x Ca x )(Ti 1-y Ca y )O3 100mol%, R2O3 0.3-3mol%, MgO 0.1-3mol%, MnO2 0.1-5mol%, BaO 0.1-2mol%, SiO2 0.1-2mol%; wherein R2O3 is a rare earth element oxide, which is at least one of Y2O3, Ho2O3, Dy2O3, and Yb2O3; the (Ba 1-x Ca x )(Ti 1-y Ca y )The particle size of the O3 matrix is ​​80~250nm.

[0032] The preparation method of the BCT-based dielectric material comprises the following steps:

[0033] (1) will (Ba 1-x Ca x )(Ti 1-y Ca y ) O3 powder is mixed with a dispersion medium (water, alcohol, isopropanol can be selected), ball-milled for 4-10 hours and then dispersed to obtain a suspension of BCT matrix material;

[0034] (2) dissolving soluble metal salts of coating elements in deionized water according to molar fractions to obtain coating element metal salt solutions; the coating elements include R, Mg, Mn and Ba;

[0035] (3) adding the coating element metal salt solution and silica sol dropwise to the suspension of the BCT matrix material obtained in step (1), stirring and mixing uniformly to obtain a preliminary slurry; wherein the preparation process of the silica sol is: mixing silicon alkoxide with ethanol, acetic acid and deionized water in a certain volume ratio to obtain the silica sol.

[0036] (4) adjusting the pH of the preliminary slurry to 6-10 with ammonia water to gradually precipitate the coated elements, aging for 1-2 hours, and obtaining a suspension of BCT-based dielectric material particles with a uniform surface coating;

[0037] (5) The BCT-based dielectric material particle suspension is granulated and dried, and then sintered to obtain a dielectric material powder; wherein the sintering temperature is 300-600° C. and the sintering time is 2-8 hours.

[0038] The present invention also provides a multilayer ceramic capacitor, the dielectric material of which adopts the BCT-based dielectric material mentioned above.

[0039] The preparation method of the multilayer ceramic capacitor is specifically as follows: adding a dispersant to a BCT-based dielectric material powder, dispersing it in a solvent, adding a binder after uniform dispersion, wherein the binder is preferably PVB, mixing and ball milling, and then performing cast drying to obtain a raw film strip of a certain thickness, and then performing electrode printing, lamination, equalizing pressing, cutting, debinding, sintering, chamfering, and end-sealing processes to obtain a base metal inner electrode multilayer ceramic capacitor.

[0040] In the above preparation method, the process conditions for debinding are: heating to 200-300° C. at a heating rate of 0.1-1° C. / min and keeping the temperature for 40-60 hours.

[0041] In the above preparation method, the sintering is divided into two stages: reducing atmosphere sintering and reoxidation sintering; the conditions for reducing atmosphere sintering are: heating to 1100-1300°C at a heating rate of 5-40°C / min and keeping the temperature for 1-3h, and the oxygen partial pressure in this stage is 10 -8 ~10 -13 atm; the reoxidation sintering conditions are: cooling to 800-1100°C at a cooling rate of 5-20°C / min and keeping warm for 3-8h. The oxygen partial pressure at this stage is 10 -3 ~10 -5 atm.

[0042] The present invention will be further described below by means of specific examples.

[0043] Example 1

[0044] The composition expression of the dielectric material in this embodiment 1 is:

[0045] 100 mol% (Ba 0.95 Ca 0.05 )(Ti 0.98 Ca 0.02 )O3-2mol%MgO-1mol%MnO2-1mol%BaO-1mol%SiO2-1.7mol%Dy2O3.

[0046] The preparation method of the dielectric material is as follows:

[0047] According to the stoichiometric ratio of the above composition expression, 100 nm of (Ba 0.95 Ca 0.05 )(Ti 0.98 Ca 0.02)O3 powder is mixed with water, ball-milled for 5 hours and then dispersed to obtain a suspension of BCT matrix material; soluble metal salts of Mg, Mn, Ba and Dy are dissolved in a certain amount of deionized water to form a coating element metal salt solution; SiO2 alkoxide is uniformly mixed with ethanol, acetic acid and deionized water in a certain volume ratio to obtain silica sol; the coating element metal salt solution and silica sol are dropped into the suspension of BCT-based material, stirred and mixed uniformly to obtain a preliminary slurry; the pH of the preliminary slurry is adjusted to 7 with ammonia water to gradually precipitate the coating element, aged for 2 hours, and a BCT-based dielectric material particle suspension with the surface uniformly coated with the doping element is obtained; the BCT-based dielectric material particle suspension is granulated and dried, and then sintered to obtain a dielectric material powder; wherein the sintering temperature is 500°C and the sintering time is 5 hours.

[0048] Add 8wt% dispersant to the dielectric material powder, use ethanol and ethyl acetate as solvents for dispersion treatment; add 8wt% binder PVB after uniform dispersion, mix and ball mill for 20 hours, and then let it stand to remove bubbles. Then, cast and dry to obtain a raw film strip with a thickness of 2μm, print it with Ni inner electrode, and then perform lamination, equalization, cutting, debinding, sintering, chamfering, and end-sealing processes to obtain a 0805 size, 6.3V rated voltage, 6.3μF-X7R BCT-based base metal inner electrode multilayer ceramic capacitor.

[0049] The electrical performance of BCT-based multilayer ceramic capacitors was tested. The room temperature resistance was measured using an Agilent Technologies, 4339B high resistance meter, and the capacitance change with temperature was measured using an Agilent Technologies, 4980A; the DC bias characteristics, room temperature capacitance and loss were measured using an Agilent Technologies, 4294A precision impedance analyzer; and the accelerated aging characteristics were measured using a TH 2683A DC resistance meter.

[0050] The BCT-based multilayer ceramic capacitor of Example 1 has a capacitance of 6 μF, a room temperature dielectric loss of 3.2%, a room temperature resistance of 250 MΩ, an average grain size of the dielectric layer of 122 nm, and a capacitance variation of less than ±15% within a temperature range of -55 to 125° C., meeting the performance requirements of the X7R MLCC dielectric material with a 0805 size and a rated voltage of 6.3 V. Its performance parameters are shown in Table 1.

[0051] Table 1 Performance parameters of multilayer ceramic capacitors of Example 1

[0052]

[0053] Example 2

[0054] The composition expression of the dielectric material in this embodiment 2 is:

[0055] 100 mol% (Ba 0.95 Ca 0.05 )(Ti 0.97 Ca 0.03 )O3-2mol%MgO-1mol%MnO2-1mol%BaO-1mol%SiO2-1.2mol%Yb2O3-1.2mol%Y2O3.

[0056] The preparation method of the dielectric material is as follows:

[0057] According to the stoichiometric ratio of the above composition expression, 100 nm of (Ba 0.95 Ca 0.05 )(Ti 0.97 Ca 0.03 )O3 powder is mixed with water, ball-milled for 5 hours and then dispersed to obtain a suspension of BCT matrix material; soluble metal salts of Mg, Mn, Ba, Yb, and Y are dissolved in a certain amount of deionized water to form a coating element metal salt solution; SiO2 alkoxide is uniformly mixed with ethanol, acetic acid, and deionized water in a certain volume ratio to obtain silica sol; the coating element metal salt solution and silica sol are dropped into the suspension of BCT-based material, stirred and mixed uniformly to obtain a preliminary slurry; the pH of the preliminary slurry is adjusted to 7 with ammonia water to gradually precipitate the coating element, aged for 2 hours, and a BCT-based dielectric material particle suspension with a surface uniformly coated with doped elements is obtained; the BCT-based dielectric material particle suspension is granulated and dried, and then sintered to obtain a dielectric material powder; wherein the sintering temperature is 500°C and the sintering time is 5 hours.

[0058] Add 10wt% dispersant to the dielectric material powder, use ethanol and ethyl acetate as solvents for dispersion treatment; add 10wt% binder PVB after uniform dispersion, mix and ball mill for 28h and then let it stand to remove bubbles. Then cast and dry to obtain a raw film strip with a thickness of 3μm, print with Ni inner electrode, and then perform lamination, equalization, cutting, debinding, sintering, chamfering, and end-sealing processes to obtain an X8R BCT-based base metal inner electrode multilayer ceramic capacitor with a size of 0805 and a rated voltage of 25V.

[0059] The performance test of the BCT-based multilayer ceramic capacitor of Example 2 was carried out. The capacitance value of the BCT-based multilayer ceramic capacitor is 17.3μF, the room temperature dielectric loss is 3.7%, the room temperature resistance is 250MΩ, the average grain size of the dielectric layer is 157nm, and the capacitance changes within the temperature range of -55 to 150°C by less than ±15%, meeting the performance of the X8R type MLCC dielectric material with a 0805 size and a rated voltage of 25V. Its various performance parameters are shown in Table 2.

[0060] Table 2 Performance parameters of multilayer ceramic capacitors of Example 2

[0061]

[0062] Example 3

[0063] The composition expression of the dielectric material in this embodiment 3 is:

[0064] 100 mol% (Ba 0.97 Ca 0.03 )(Ti 0.98 Ca 0.02 )O3-2mol%MgO-1mol%MnO2-1mol%BaO-1mol%SiO2-1mol%Ho2O3-1mol%Y2O3.

[0065] The preparation method of the dielectric material is as follows:

[0066] According to the stoichiometric ratio of the above composition expression, 100 nm of (Ba 0.97 Ca 0.03 )(Ti 0.98 Ca 0.02 )O3 powder is mixed with water, ball-milled for 5 hours and then dispersed to obtain a suspension of BCT matrix material; soluble metal salts of Mg, Mn, Ba, Y and Ho are dissolved in a certain amount of deionized water to form a coating element metal salt solution; SiO2 alkoxide is uniformly mixed with ethanol, acetic acid and deionized water in a certain volume ratio to obtain silica sol; the coating element metal salt solution and silica sol are dropped into the suspension of BCT-based material, stirred and mixed uniformly to obtain a preliminary slurry; the pH of the preliminary slurry is adjusted to 7 with ammonia water to gradually precipitate the coating element, aged for 2 hours, and a BCT-based dielectric material particle suspension with the surface uniformly coated with the doping element is obtained; the BCT-based dielectric material particle suspension is granulated and dried, and then sintered to obtain a dielectric material powder; wherein the sintering temperature is 500°C and the sintering time is 5 hours.

[0067] Add 8.5wt% dispersant to the dielectric material powder, use ethanol and ethyl acetate as solvents for dispersion treatment; add 8wt% binder PVB after uniform dispersion, mix and ball mill for 25h, and then let it stand to remove bubbles. Then, cast and dry to obtain a raw film strip with a thickness of 3μm, print it with Ni inner electrode, and then perform lamination, equalization, cutting, debinding, sintering, chamfering, and end-sealing processes to obtain a 1210 size, 100V rated voltage, X8S type BCT-based base metal inner electrode multilayer ceramic capacitor.

[0068] The performance of the BCT-based multilayer ceramic capacitor of Example 3 was tested. The metallographic micrograph of the end surface of the X8S type BME-MLCC is shown in FIG. Figure 1 As shown; the long axis cross-section metallographic micrograph of X8S type BME-MLCC is shown Figure 2 As shown; the SEM image of X8S BME-MLCC dielectric material grains is as follows Figure 3 As shown; the relationship between X8S type BME-MLCC capacitor and temperature is shown in Figure 4 The BCT-based multilayer ceramic capacitor has a capacitance of 9.2μF, a room temperature dielectric loss of 4.5%, a room temperature resistance of 350MΩ, an average grain size of 188nm, and a capacitance variation of less than ±22% within a temperature range of -55 to 150°C, meeting the performance of X8S MLCC dielectric materials with a size of 1210 and a rated voltage of 100V. Its performance parameters are shown in Table 3.

[0069] Table 3 Performance parameters of multilayer ceramic capacitors of Example 3

[0070]

[0071] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any modifications or equivalent transformations made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A BCT-based dielectric material, characterized in that: The composition expression of the dielectric material is (Ba 1-x Ca x )(Ti 1-y Ca y )O3-R2O3-MgO-MnO2-BaO-SiO2, among which (Ba 1-x Ca x )(Ti 1-y Ca y )O3 is the matrix, R2O3-MgO-MnO2-BaO-SiO2 is the doping coating material; in the composition expression, x and y are molar fractions and meet the following conditions: 0.01≤x≤0.08, 0.01≤y≤0.05; the molar contents of the matrix and the doping coating material are as follows: (Ba 1-x Ca x )(Ti 1-y Ca y )O3 100mol%, R2O3 0.3-3mol%, MgO 0.1-3mol%, MnO2 0.1-5mol%, BaO 0.1-2mol%, SiO2 0.1-2mol%; wherein R2O3 is a rare earth element oxide, which is at least one of Y2O3, Ho2O3, Dy2O3, and Yb2O3; the (Ba 1-x Ca x )(Ti 1-y Ca y )The particle size of the O3 matrix is ​​80~250nm.

2. A BCT-based dielectric material according to claim 1, characterized in that: The molar contents of the doping coating materials are as follows: R2O3 0.7-2.1 mol%, MgO 1-2.5 mol%, MnO2 1-3.5 mol%, BaO 0.5-1.5 mol%, and SiO2 0.5-1.5 mol%.

3. A method for preparing the BCT-based dielectric material according to claim 1 or 2, characterized in that: The steps include: (1) will (Ba 1-x Ca x )(Ti 1-y Ca y ) O3 powder is mixed with a dispersion medium, and after ball milling and dispersion, a suspension of BCT matrix material is obtained; (2) dissolving soluble metal salts of coating elements in deionized water according to molar fractions to obtain coating element metal salt solutions; the coating elements include R, Mg, Mn and Ba; (3) adding the coating element metal salt solution and silica sol dropwise to the suspension of the BCT matrix material obtained in step (1), stirring and mixing evenly to prepare a preliminary slurry; (4) adjusting the pH of the preliminary slurry to 6-10, allowing the coated elements to gradually precipitate, and aging for 1-2 hours to obtain a suspension of BCT-based dielectric material particles with a uniform surface coating; (5) The BCT-based dielectric material particle suspension is granulated and dried, and then sintered to obtain a dielectric material powder.

4. The method for preparing the BCT-based dielectric material according to claim 3, characterized in that: The preparation process of the silica sol is as follows: silicon alkoxide is uniformly mixed with ethanol, acetic acid and deionized water in a certain volume ratio to obtain the silica sol.

5. The method for preparing the BCT-based dielectric material according to claim 3, characterized in that: In step (4), aqueous ammonia is used to adjust the pH of the preliminary slurry.

6. The method for preparing the BCT-based dielectric material according to claim 3, characterized in that: The sintering temperature in step (5) is 300-600° C. and the sintering time is 2-8 hours.

7. A multilayer ceramic capacitor, characterized in that: The dielectric material of the multilayer ceramic capacitor adopts the BCT-based dielectric material according to claim 1 or 2.

8. A method for preparing a multilayer ceramic capacitor according to claim 7, characterized in that: Add a dispersant to the BCT-based dielectric material powder and disperse it in a solvent. After uniform dispersion, add a binder, mix and mill, and then perform tape casting and drying to obtain a raw film tape of a certain thickness. Then, the raw film tape is subjected to electrode printing, lamination, equalizing pressing, cutting, debinding, sintering, chamfering, and end-sealing processes to obtain a base metal inner electrode multilayer ceramic capacitor.

9. The method for preparing a multilayer ceramic capacitor according to claim 8, characterized in that: The process conditions for debinding are: heating to 200-300°C at a heating rate of 0.1-1°C / min and keeping the temperature for 40-60h.

10. The method for preparing a multilayer ceramic capacitor according to claim 8, characterized in that: The sintering process is divided into two stages: reducing atmosphere sintering and reoxidation sintering. The conditions for reducing atmosphere sintering are: heating to 1100-1300°C at a heating rate of 5-40°C / min and keeping the temperature for 1-3h. The oxygen partial pressure in this stage is 10 -8 ~10 -13 atm; the reoxidation sintering conditions are: cooling to 800-1100°C at a cooling rate of 5-20°C / min and keeping warm for 3-8h. The oxygen partial pressure at this stage is 10 -3 ~10 -5 atm.

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