A high dielectric constant ceramic capacitor dielectric and its preparation method

Abstract

The application belongs to the technical field of dielectric ceramic synthesis, and discloses a high-dielectric-constant ceramic capacitor dielectric and a preparation method. 1‑x La x Cu3Ti 4‑x Y x O 12 , 0.03≤x≤0.15; the chemical composition of the pre-sintering material B is CaCu 3‑y Mg y Ti4O 12 , 0.7≤y≤1.2. The preparation method of the high-dielectric-constant ceramic capacitor dielectric comprises the following steps: (1) preparing a mixed powder; (2) granulating, grinding and dry-pressing the mixed powder to prepare a round blank; and (3) sintering the round blank to prepare the high-dielectric-constant ceramic capacitor dielectric. The high-dielectric-constant ceramic capacitor dielectric prepared by the application has the advantages of high dielectric constant and low loss, the manufacturing process is simple, the raw material cost is low, and the application is suitable for popularization and use.

Description

Technical Field

[0001] This application relates to the field of dielectric ceramic synthesis technology, and in particular to a high dielectric constant ceramic capacitor dielectric and its preparation method. Background Technology

[0002] With the increasing demands for high integration and high reliability in electronic devices, high dielectric constant materials have become a hot topic. Calcium copper titanate (CaCu3Ti4O) is one such material. 12 CCTO (body-centered cubic perovskite oxide) is a perovskite cubic crystal structure and is one of the most representative new high-dielectric-constant materials in recent years. Its dielectric constant reaches 10⁴–10⁵, remains stable over a wide temperature and frequency range, and does not undergo a ferroelectric-paraelectric phase transition. Furthermore, CCTO has a simple preparation process and low sintering temperature, giving it potential advantages for industrial production. CCTO is a high-dielectric barrier layer material. As a body-centered cubic perovskite oxide, it possesses high dielectric constant, good temperature stability, and frequency stability. However, CCTO has high dielectric loss and is highly sensitive to processing. Due to its high dielectric constant and good temperature stability, CCTO can be used as a dielectric material for ceramic capacitors.

[0003] The miniaturization requirements of high-energy storage devices and capacitors necessitate that the core dielectric materials possess high dielectric constants, low losses, and excellent breakdown resistance. Research indicates that ferroelectric materials, such as BaTiO3, meet the high dielectric constant requirement, but their dielectric constant varies significantly with temperature; non-ferroelectric materials, such as CaCuTi3O4... 12 The dielectric constant of materials such as (CCTO) can reach over 10⁵ over a wide temperature range, but the dielectric loss is very high (>0.1). Therefore, there is a need to prepare a dielectric ceramic material that simultaneously possesses a high dielectric constant, low loss, and certain resistance to high voltage breakdown. Summary of the Invention

[0004] To address at least one of the aforementioned technical problems and to develop a capacitor ceramic dielectric that simultaneously possesses high dielectric constant, low loss, and certain resistance to high voltage breakdown, this application provides a high dielectric constant ceramic capacitor dielectric and its preparation method.

[0005] On one hand, this application provides a high dielectric constant ceramic capacitor dielectric, the raw materials of which are composed of pre-fired material A and pre-fired material B in a weight ratio of 3-5:18-25; the chemical composition of pre-fired material A is Ca. 1-x La x Cu3Ti 4-x Y x O 12 Wherein, 0.03≤x≤0.15; the chemical composition of the pre-calcined material B is CaCu3-y Mg y Ti4O 12 , where 0.7≤y≤1.2.

[0006] Optionally, the raw materials for the high dielectric constant ceramic capacitor dielectric consist of pre-sintered material A and pre-sintered material B in a weight ratio of 3.5:18-22.

[0007] Optionally, in the pre-fired material A, x is 0.08; in the pre-fired material B, y is 0.9.

[0008] Optionally, the pre-burned material A is prepared by: according to Ca 1-x La x Cu3Ti 4-x Y x O 12 Copper nitrate, calcium nitrate, lanthanum nitrate, yttrium nitrate, and citric acid were weighed according to the stoichiometric ratio, mixed, and added to an organic solvent. The mixture was stirred to dissolve the raw materials to obtain a mixture A. Tetrabutyl titanate was added and stirred. Mixture A was kept at a constant temperature of 75-90℃ for 5-8 hours to form sol A. Sol A was dried at 95-115℃ for 10-13 hours to form a dry gel A. The gel was ground and pre-sintered at 700-780℃ for 1.5-3.5 hours. After cooling and grinding, pre-sintered material A was obtained. The weight ratio of citric acid to tetrabutyl titanate was 1.3-1.8:1.

[0009] Optionally, the pre-burned material B is prepared by: according to CaCu 3-y Mg y Ti4O 12 Copper nitrate, calcium nitrate, magnesium nitrate, and citric acid were weighed according to the stoichiometric ratio, mixed, and added to an organic solvent. The mixture was stirred to dissolve the raw materials, resulting in a mixture B. Tetrabutyl titanate was added and stirred. The mixture B was kept at a constant temperature of 75-90℃ for 5-8 hours to form a sol B. The sol B was dried at 95-115℃ for 10-13 hours to form a dry gel B. The gel was ground and pre-sintered at 800-850℃ for 1.5-3 hours. After cooling and grinding, the pre-sintered material B was obtained. The weight ratio of citric acid to tetrabutyl titanate was 1.3-1.8:1.

[0010] Optionally, the pre-sintered material A and pre-sintered material B are pre-sintered in a mixed gas atmosphere of oxygen and nitrogen, wherein the volume percentage of oxygen is 30-55%.

[0011] Secondly, this application provides a method for preparing the above-mentioned high dielectric constant ceramic capacitor dielectric, including the following steps: S1, mixing pre-sintered material A and pre-sintered material B, ball milling and drying to obtain a mixed powder;

[0012] S2. Add a binder to the mixed powder obtained in step S1 and stir it. Granulate the powder and grind it to 30-50 mesh. Then, dry press the mixed powder into a round blank under a pressure of 20-35 MPa.

[0013] S3. Place the circular preform obtained in step S2 into an electric furnace, heat it to 600-700℃ under a nitrogen atmosphere and hold it for 1-2 hours to remove the glue, then heat it to 1050-1130℃ and hold it for 11.5-14 hours to obtain a high dielectric constant ceramic capacitor dielectric.

[0014] Optionally, the binder used in step S2 is PVA, and the weight ratio of PVA to the mixed powder is 0.06-0.15:1.

[0015] Optionally, in step S3, the temperature is first raised to 100-150℃ at a heating rate of 1.5-3℃ / min and held for 10-20 minutes for drying. Then, the temperature is raised to 600-700℃ at a heating rate of 3-6℃ / min and held for 1-2 hours for debinding. Finally, the temperature is raised to 1050-1130℃ at a heating rate of 9-12℃ / min and held for 11.5-14 hours for sintering.

[0016] In summary, the present invention has at least one of the following beneficial technical effects:

[0017] 1. The high dielectric constant ceramic capacitor dielectric obtained in this application has the advantages of both high dielectric constant and low loss. At the same time, the high dielectric constant ceramic capacitor dielectric obtained in this application has a high resistivity, which can improve the operating voltage and breakdown voltage of the capacitor made therefrom without affecting its dielectric performance.

[0018] 2. The high dielectric constant ceramic capacitor dielectric of this application has a simple preparation process, low equipment requirements, and low raw material cost, making it suitable for widespread use. Detailed Implementation

[0019] The present application will be further described in detail below with reference to the embodiments.

[0020] This application designs a high dielectric constant ceramic capacitor dielectric, the raw materials of which are composed of pre-sintered material A and pre-sintered material B in a weight ratio of 3-5:18-25; the chemical composition of pre-sintered material A is Ca. 1-x La x Cu3Ti 4-x Y x O 12 Wherein, 0.03≤x≤0.15; the chemical composition of the pre-calcined material B is CaCu 3-y Mg y Ti4O 12, where 0.7≤y≤1.2.

[0021] The preparation method of the pre-burned material A is as follows: based on Ca 1-x La x Cu3Ti 4-x Y x O 12 Copper nitrate, calcium nitrate, lanthanum nitrate, yttrium nitrate, and citric acid were weighed according to the stoichiometric ratio, mixed, and added to an organic solvent. The mixture was stirred to dissolve the raw materials to obtain a mixture A. Tetrabutyl titanate was added and stirred. Mixture A was kept at a constant temperature of 75-90℃ for 5-8 hours to form sol A. Sol A was dried at 95-115℃ for 10-13 hours to form a dry gel A. The gel was ground and pre-sintered at 700-780℃ for 1.5-3.5 hours. After cooling and grinding, pre-sintered material A was obtained. The weight ratio of citric acid to tetrabutyl titanate was 1.3-1.8:1.

[0022] The preparation method of the pre-burned material B is as follows: based on CaCu 3-y Mg y Ti4O 12 Copper nitrate, calcium nitrate, magnesium nitrate, and citric acid were weighed according to the stoichiometric ratio, mixed, and added to an organic solvent. The mixture was stirred to dissolve the raw materials, resulting in a mixture B. Tetrabutyl titanate was added and stirred. The mixture B was kept at a constant temperature of 75-90℃ for 5-8 hours to form a sol B. The sol B was dried at 95-115℃ for 10-13 hours to form a dry gel B. The gel was ground and pre-sintered at 800-850℃ for 1.5-3 hours. After cooling and grinding, the pre-sintered material B was obtained. The weight ratio of citric acid to tetrabutyl titanate was 1.3-1.8:1.

[0023] The high dielectric constant ceramic capacitor dielectric of this application is prepared by the following method, including the following steps:

[0024] S1. Mix pre-calcined material A and pre-calcined material B, ball mill and dry to obtain mixed powder;

[0025] S2. Add a binder to the mixed powder obtained in step S1 and stir it. Granulate the powder and grind it to 30-50 mesh. Then, dry press the mixed powder into a round blank under a pressure of 20-35 MPa.

[0026] S3. Place the circular preform obtained in step S2 into an electric furnace, heat it to 600-700℃ under a nitrogen atmosphere and hold it for 1-2 hours to remove the glue, then heat it to 1050-1130℃ and hold it for 11.5-14 hours to obtain a high dielectric constant ceramic capacitor dielectric.

[0027] The technical problem solved by this application is CaCuTi3O 12While (CCTO) dielectric materials have high dielectric constants, their dielectric losses are also very high (>0.1%). Therefore, there is a need to prepare a dielectric ceramic material that simultaneously possesses high dielectric constant, low loss, and certain resistance to high-voltage breakdown. The high-dielectric-constant ceramic capacitor dielectric obtained in this application combines the advantages of high dielectric constant and low loss. Furthermore, the high-dielectric-constant ceramic capacitor dielectric obtained in this application has high resistivity, which can improve the operating voltage and breakdown voltage of the capacitor without affecting its dielectric properties. The preparation process in this application is simple, requires relatively low-end equipment, and uses inexpensive raw materials, making it suitable for widespread use.

[0028] The raw materials used in the embodiments of this application are sourced from the following sources:

[0029] Calcium nitrate, Sinopharm Chemical Reagent Co., Ltd.;

[0030] Lanthanum nitrate, Sinopharm Chemical Reagent Co., Ltd.;

[0031] Copper nitrate, Sinopharm Chemical Reagent Co., Ltd.;

[0032] Tetrabutyl titanate, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0033] Yttrium nitrate, Sinopharm Chemical Reagent Co., Ltd.

[0034] Citric acid, Sinopharm Chemical Reagent Co., Ltd.;

[0035] Magnesium nitrate, Sinopharm Chemical Reagent Co., Ltd.

[0036] Preparation Examples 1-3

[0037] Preparation Examples 1-3 are pre-burned materials A prepared with different raw material ratios.

[0038] In Preparation Example 1, x is taken as 0.03, and correspondingly, the chemical composition of pre-calcined material A is Ca. 0.97 La 0.03 Cu3Ti 3.97 Y 0.03 O 12 Accordingly, the quantities of calcium nitrate, lanthanum nitrate, copper nitrate, tetrabutyl titanate, and yttrium nitrate required to prepare a unit mass of pre-burned material A are determined accordingly, and the specific quantities are shown in Table 1.

[0039] In Preparation Example 2, x is taken as 0.08, and correspondingly, the chemical composition of pre-calcined material A is Ca. 0.92 La 0.08 Cu3Ti 3.92 Y 0.08 O 12Accordingly, the quantities of calcium nitrate, lanthanum nitrate, copper nitrate, tetrabutyl titanate, and yttrium nitrate required to prepare a unit mass of pre-burned material A are determined accordingly, and the specific quantities are shown in Table 1.

[0040] In Preparation Example 3, x is taken as 0.15, and correspondingly, the chemical composition of pre-calcined material A is Ca. 0.85 La 0.15 Cu3Ti 3.85 Y 0.15 O 12 Accordingly, the quantities of calcium nitrate, lanthanum nitrate, copper nitrate, tetrabutyl titanate, and yttrium nitrate required to prepare a unit mass of pre-burned material A are determined accordingly, and the specific quantities are shown in Table 1.

[0041] In Preparation Examples 1-3, the weight ratio of citric acid to tetrabutyl titanate was 1.5:1.

[0042] Table 1

[0043]

[0044] The preparation process of Examples 1-3 is as follows:

[0045] According to Ca 1-x La x Cu3Ti 4-x Y x O 12 Copper nitrate, calcium nitrate, lanthanum nitrate, yttrium nitrate, and citric acid were weighed according to the stoichiometric ratio, mixed, and added to 95wt% ethanol. The mixture was stirred to dissolve the raw materials to obtain mixture A. Tetrabutyl titanate was added, stirred, and kept at a constant temperature of 80℃ in a water bath for 6 hours to form sol A. Sol A was dried at 110℃ for 12 hours to form dry gel A. The gel A was then ground and pre-sintered at 750℃ for 2.5 hours under a nitrogen atmosphere. After cooling, the gel was ground to 100 mesh to obtain pre-sintered material A.

[0046] Preparation Examples 4-6

[0047] Preparation Examples 4-6 show pre-burned materials B prepared with different raw material ratios.

[0048] In Preparation Example 4, y is taken as 0.7, and correspondingly, the chemical composition of the pre-calcined material B is CaCu. 2.3 Mg 0.7 Ti4O 12 Accordingly, the quantities of copper nitrate, calcium nitrate, magnesium nitrate, and tetrabutyl titanate required to prepare a unit mass of pre-burned material B are determined accordingly, and the specific quantities are shown in Table 2.

[0049] In Preparation Example 5, y is taken as 0.9, and correspondingly, the chemical composition of the pre-calcined material B is CaCu. 2.1 Mg 0.9 Ti4O12 Accordingly, the quantities of copper nitrate, calcium nitrate, magnesium nitrate, and tetrabutyl titanate required to prepare a unit mass of pre-burned material B are determined accordingly, and the specific quantities are shown in Table 2.

[0050] In Preparation Example 6, y is taken as 1.2, and correspondingly, the chemical composition of the pre-calcined material B is CaCu. 1.8 Mg 1.2 Ti4O 12 Accordingly, the quantities of copper nitrate, calcium nitrate, magnesium nitrate, and tetrabutyl titanate required to prepare a unit mass of pre-burned material B are determined accordingly, and the specific quantities are shown in Table 2.

[0051] In Preparation Examples 4-6, the weight ratio of citric acid to tetrabutyl titanate was 1.5:1.

[0052] Table 2

[0053]

[0054] The preparation process of Examples 4-6 is as follows:

[0055] According to CaCu 3-y Mg y Ti4O 12 Copper nitrate, calcium nitrate, magnesium nitrate, and citric acid were weighed according to the stoichiometric ratio, mixed, and added to 95wt% ethanol. The mixture was stirred to dissolve the raw materials to obtain mixture B. Tetrabutyl titanate was added and stirred. Mixture B was kept at a constant temperature of 80℃ in a water bath for 6.5h to form sol B. Sol B was dried at 110℃ for 12h to form dry gel B. The gel was then ground and pre-sintered at 820℃ for 2.5h under a nitrogen atmosphere. After cooling, the gel was ground to 100 mesh to obtain pre-sintered material B.

[0056] Examples 1-9

[0057] Examples 1-9 are high dielectric constant ceramic capacitor dielectrics obtained by sintering pre-fired materials A and B of different types and amounts, as detailed in Table 3.

[0058] Table 3

[0059]

[0060]

[0061] The preparation process of Examples 1-9 is as follows:

[0062] S1. Mix pre-burned material A and pre-burned material B, ball mill and dry to obtain mixed powder; wherein, during the ball milling process, the weight ratio of mixed powder, balls and ball milling media is 1:2:2, the ball milling media is anhydrous ethanol, the ball mill speed is 600 rpm, the ball milling time is 2.5 h, and then it is dried at 120℃ for 5 h.

[0063] S2. PVA is added to the mixed powder obtained in step S1 and stirred. The weight ratio of PVA to the mixed powder is 0.1:1. Granulation is performed and the particles are ground to 35 mesh. Then, the granulated mixed powder is dry-pressed under a pressure of 30 MPa to obtain a circular preform. A circular preform with a thickness of 0.8 mm and a diameter of 8 mm is obtained.

[0064] S3. Place the circular preform obtained in step S2 into an electric furnace. Under a nitrogen atmosphere, first heat the preform to 130°C at a heating rate of 2.5°C / min and hold for 15 min to dry it. Then heat the preform to 650°C at a heating rate of 5°C / min and hold for 1.5 h to remove the binder. Finally heat the preform to 1090°C at a heating rate of 10°C / min and hold for 13 h to sinter it. Then cool the preform to room temperature at a cooling rate of 5°C / min to obtain a high dielectric constant ceramic capacitor dielectric.

[0065] Examples 10-12

[0066] Example 10 is based on Example 2, except that: in Example 10, both pre-sintered material A and pre-sintered material B are pre-sintered in a mixed gas atmosphere of oxygen and nitrogen, wherein the oxygen volume percentage is 30%.

[0067] Example 11 is based on Example 2, except that: in Example 11, both pre-sintered material A and pre-sintered material B are pre-sintered in a mixed gas atmosphere of oxygen and nitrogen, wherein the oxygen volume percentage is 40%.

[0068] Example 12 is based on Example 2, except that: in Example 12, both pre-sintered material A and pre-sintered material B are pre-sintered in a mixed gas atmosphere of oxygen and nitrogen, wherein the oxygen volume percentage is 55%.

[0069] Comparative Examples 1-7

[0070] Comparative Example 1 is based on Example 2, except that: in Comparative Example 1, pre-fired material B is replaced with an equal molar amount of pre-fired material A, that is, the pre-fired material is 2550g of Ca. 0.92 La 0.08 Cu3Ti 3.92 Y 0.08 O 12 .

[0071] Comparative Example 2 is based on Example 2, except that the pre-calcined material B is replaced with an equal molar amount of CaCu in Comparative Example 2. 2.1 Ni 0.9 Ti4O 12 The preparation process of pre-burned material B remains unchanged.

[0072] Comparative Example 3 is based on Example 2, except that the pre-calcined material B is replaced with an equal molar amount of CaCu in Comparative Example 3. 2.1 Zn 0.9 Ti4O 12 The preparation process of pre-burned material B remains unchanged.

[0073] Comparative Example 4 is based on Example 2, except that in Comparative Example 4, the y value of pre-calcined material B is 1.5, that is, the chemical composition of pre-calcined material B is CaCu. 1.5 Mg 1.5 Ti4O 12 The preparation process of pre-burned material B remains unchanged.

[0074] Comparative Example 5 is based on Example 2, except that in Comparative Example 5, the pre-calcined material A is replaced with an equal molar amount of Ca. 0.92 La 0.08 Cu3Ti 3.92 Al 0.08 O 12 The preparation process of pre-burned material A remains unchanged.

[0075] Comparative Example 6 is based on Example 2, except that the pre-calcined material A is replaced with an equal molar amount of Ca in Comparative Example 6. 0.92 Bi 0.08 Cu3Ti 3.92 Y 0.08 O 12 The preparation process of pre-burned material A remains unchanged.

[0076] Comparative Example 7 is based on Example 2, except that in Comparative Example 7, the x value of pre-fired material A is 0.3, that is, the chemical composition of pre-fired material A is Ca. 0.7 La 0.3 Cu3Ti 3.7 Y 0.3 O 12 The preparation process of pre-burned material A remains unchanged.

[0077] Application Example 1-12

[0078] Electrodes were printed on both sides of the ceramic capacitor dielectric prepared in Examples 1-12 using copper metal electrode paste, and then calcined in nitrogen at 800°C for 20 minutes to obtain a copper electrode ceramic capacitor chip. Leads were then soldered and encapsulated with polyimide film to obtain the corresponding ceramic capacitor. The ceramic capacitors prepared in Examples 1-12 correspond to the high dielectric constant ceramic capacitor dielectrics prepared in Examples 1-12 respectively.

[0079] Application Comparative Examples 1-7

[0080] Electrodes were printed on both sides of the ceramic capacitor dielectric prepared in Comparative Examples 1-7 using copper metal electrode paste, and then calcined in nitrogen at 800°C for 20 minutes to obtain a copper electrode ceramic capacitor chip. Leads were then soldered and encapsulated with polyimide film to obtain the corresponding ceramic capacitor. The ceramic capacitors prepared in Comparative Examples 1-7 were then used to sequentially apply the high dielectric constant ceramic capacitor dielectrics prepared in Comparative Examples 1-7.

[0081] Performance testing

[0082] 1. Test the dielectric constant and dielectric loss of the ceramic capacitors corresponding to Case 1-12 and Application Comparison Example 1-7. The test conditions are: temperature 25℃±2℃, humidity 55%~65%, test frequency 1KHz±50Hz, and test bias 1.0V ACRMS.

[0083] 2. The resistivity of the high dielectric constant ceramic capacitor dielectrics prepared in Examples 1-12 and Comparative Examples 1-7 was measured.

[0084] The test results are shown in Tables 4 and 5.

[0085] Table 4

[0086] Dielectric constant (1kHz) Dielectric loss (1kHz) Application Example 1 46850 0.011 Application Example 2 50760 0.0073 Application Example 3 47980 0.0088 Application Example 4 47530 0.0098 Application Example 5 45910 0.026 Application Example 6 48440 0.022 Application Example 7 43490 0.02 Application Example 8 42720 0.017 Application Example 9 49260 0.013 Application Example 10 51950 0.011 Application Example 11 55790 0.007 Application Example 12 52540 0.0065 Application Comparative Example 1 27750 0.0082 Application Comparative Example 2 23890 0.045 Application Comparative Example 3 18860 0.039 Application Comparative Example 4 31560 0.032 Application Comparative Example 5 35250 0.022 Application Comparative Example 6 20630 0.048 Application Comparative Example 7 28130 0.057

[0087] Table 5

[0088]

[0089]

[0090] Analysis of the data in Tables 4 and 5, and comparison of the data from Examples 1-9 and Application Examples 1-9, reveals that the chemical composition of pre-calcined material A is Ca... 0.92 La 0.08 Cu3Ti 3.92 Y 0.08 O 12 The chemical composition of pre-burned material B is CaCu 2.1 Mg 0.9 Ti4O 12Furthermore, when the weight ratio of pre-sintered materials A and B is 3.5:22, the resulting high-dielectric-constant ceramic capacitor dielectric exhibits better performance in terms of dielectric constant, dielectric loss, and resistivity. Comparing the data from Example 2 and Application Example 2 with those from Examples 10-12 and Application Example 10-12, it can be seen that pre-sintering in a mixed atmosphere of oxygen and nitrogen results in better performance in terms of dielectric constant and dielectric loss. When the oxygen volume percentage is 40%, the dielectric constant of the resulting high-dielectric-constant ceramic capacitor dielectric increases significantly. Comparing Example 2 and Application Example 2 with Comparative Example 1 and Application Comparative Example 1, it can be seen that the ceramic capacitor dielectric obtained by uniformly blending and sintering pre-sintered materials A and B exhibits significantly stronger performance in dielectric constant and dielectric loss than that obtained by sintering pre-sintered material A alone. Comparing Example 2 and Application Example 2 with Comparative Examples 2-7 and Application Comparative Examples 2-7, the CaCu content in pre-sintered material B... 2.1 Mg 0.9 Ti4O 12 When the Mg element is replaced with Ni or Zn, or when the y value in pre-sintered material B is changed beyond a certain range, the dielectric constant, dielectric loss, and resistivity of the resulting ceramic capacitor dielectric are significantly reduced to varying degrees; when the Ca in pre-sintered material A is changed... 0.92 La 0.08 Cu3Ti 3.92 Y 0.08 O 12 When the La element is replaced with the Bi element, or the Y element is replaced with the Al element, or the x value in the pre-sintered material A is changed beyond a certain range, the dielectric constant, dielectric loss and resistivity of the ceramic capacitor dielectric are reduced to varying degrees.

[0091] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high dielectric constant ceramic capacitor dielectric, characterized by, The raw material is composed of pre-sintering material A and pre-sintering material B in a weight ratio of 3-5:18-25; The pre-burning material A has a chemical composition of Ca 1-x La x Cu3Ti 4-x Y x O 12 wherein 0.03≤x≤0.15; The pre-sintering material B has a chemical composition of CaCu 3-y Mg y Ti4O 12 wherein 0.7≤y≤1.2; The preparation method of the pre-sintering material A is as follows: according to the stoichiometric ratio of Cu 1-x La x Cu3Ti 4-x Y x O 12 The raw materials of copper nitrate, calcium nitrate, lanthanum nitrate, yttrium nitrate and citric acid are weighed according to the stoichiometric ratio, mixed, and then added into an organic solvent; after stirring to dissolve the raw materials, a mixed solution A is obtained; then tetrabutyl titanate is added and stirred; the mixed solution A is kept at a constant temperature of 75-90 DEG C for 5-8 h to form a sol A; the sol A is dried at 95-115 DEG C for 10-13 h to form a dry gel A; the dry gel A is ground, pre-sintered at 700-780 DEG C for 1.5-3.5 h, cooled, and ground to obtain the pre-sintering material A; wherein the weight ratio of the citric acid to the tetrabutyl titanate is 1.3-1.8:

1. The preparation method of the pre-sintering material B is as follows: according to the stoichiometric ratio of CaCu 3-y Mg y Ti4O 12 The raw materials of copper nitrate, calcium nitrate, magnesium nitrate and citric acid are weighed according to the stoichiometric ratio, mixed, and then added to an organic solvent. After stirring to dissolve the raw materials, a mixed solution B is obtained. Then, tetrabutyl titanate is added and stirred. The mixed solution B is kept at a constant temperature of 75-90 DEG C for 5-8 h to form a sol B. The sol B is dried at 95-115 DEG C for 10-13 h to form a dry gel B. The dry gel B is ground, pre-sintered at 800-850 DEG C for 1.5-3 h, cooled, and ground to obtain the pre-sintering material B. The weight ratio of the citric acid to the tetrabutyl titanate is 1.3-1.8:

1.

2. The high dielectric constant ceramic capacitor dielectric of claim 1, wherein, The raw material of the high dielectric constant ceramic capacitor medium is composed of pre-sintering material A and pre-sintering material B in a weight ratio of 3.5:18-22.

3. The high dielectric constant ceramic capacitor dielectric of claim 1, wherein, In the pre-sintering material A, x is 0.08; in the pre-sintering material B, y is 0.

9.

4. The high dielectric constant ceramic capacitor dielectric of claim 1, wherein, The pre-sintering material A and the pre-sintering material B are pre-sintered in a mixed gas atmosphere of oxygen and nitrogen, wherein the volume percentage of oxygen is 30-55%.

5. A method of producing the high dielectric constant ceramic capacitor dielectric as claimed in any one of claims 1 to 4, characterized in that, The method comprises the following steps: S1, mixing the pre-sintering material A and the pre-sintering material B, ball milling, drying, and obtaining a mixed powder; S2, adding a binder to the mixed powder obtained in the step S1 and stirring, granulating, and grinding to 30-50 mesh, and then dry pressing the mixed powder under a pressure of 20-35 MPa to obtain a round blank; S3, placing the round blank obtained in the step S2 into an electric furnace, heating to 600-700℃ under a nitrogen atmosphere, and holding for 1-2h to perform glue removal, and heating to 1050-1130℃ and holding for 11.5-14h to obtain a high dielectric constant ceramic capacitor medium.

6. The method of claim 5, wherein the high dielectric constant ceramic capacitor dielectric is prepared by the steps of: The binder used in the step S2 is PVA, and the weight ratio of the PVA to the mixed powder is 0.06-0.15:

1.

7. The method of claim 5, wherein the high dielectric constant ceramic capacitor dielectric is prepared by the steps of: In the step S3, first, dry the round blank at a heating rate of 1.5-3℃ / min to 100-150℃ and holding for 10-20 min, then remove the glue at a heating rate of 3-6℃ / min to 600-700℃ and holding for 1-2h, and finally, sinter the round blank at a heating rate of 9-12℃ / min to 1050-1130℃ and holding for 11.5-14h.

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