High-dielectric-constant NP0 type dielectric ceramic material as well as preparation method and application thereof

Abstract

The invention provides a high-dielectric-constant NP0 type dielectric ceramic material as well as a preparation method and application thereof. The high dielectric constant NP0 type dielectric ceramic material is prepared from the following raw materials: 15 mol% to 16 mol% of BaCO3 and / or BaO, 2 mol% to 6 mol% of Nd2O3, 2 mol% to 6 mol% of Sm2O3, 5 mol% to 10 mol% of Bi2O3 and 55 mol% to 70 mol% of TiO2. The ceramic dielectric material provided by the invention has medium sintering temperature, high dielectric constant, low dielectric loss and high insulation resistance, and meets the specification requirements of NP0 type dielectric ceramics.

Description

Technical Field

[0001] The present invention relates to the technical field of multifunctional electronic ceramic materials, and in particular to a high dielectric constant NP0 type dielectric ceramic material and a preparation method and application thereof. Background Art

[0002] At present, the mainstream product of ceramic capacitors is multilayer ceramic capacitors (MLCC). The development trend of electronic products is miniaturization and higher operating frequency, which requires small components that can operate at high frequencies. Compared with traditional MLCC, microwave ceramic capacitors have lower equivalent series resistance, higher quality factor and better reliability. Microwave ceramic capacitors can meet the needs of microwave and millimeter wave frequency band electronic products. Such capacitors play a key role in microwave integrated circuits (MIC) and microwave monolithic integrated circuits (MMIC), and can act as amplifiers, oscillators and mixers. Future power electronic modules also require electronic components to operate at ambient temperatures above 150°C without external cooling, which is crucial for applications in the automotive, oil and gas, aerospace and energy generation industries. In order to meet the needs of commercial microwave applications, microwave dielectrics are expected to have high dielectric constants, low dielectric losses and near-zero resonant frequency temperature coefficients. Tungsten bronze type BaO-Ln2O3-TiO2 (Ln = rare earth) ceramics have excellent microwave dielectric properties: such as dielectric constant can reach 80-90, temperature coefficient <±30ppm / ℃, and the dielectric constant of the material can be increased to more than 100 by doping with Pb ions, but it does not meet the ROHS standard. In addition, although the Nd-based tungsten bronze system has a relatively high dielectric constant, its dielectric constant temperature coefficient is about -120ppm / ℃. It is generally adjusted by compounding it with other systems with positive dielectric constant temperature coefficients, resulting in a certain sacrifice in dielectric constant and loss performance. In addition, the sintering temperature of BLT system ceramics is generally high (>1400℃), and densification sintering is difficult, which is not conducive to mass production. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, one object of the present invention is to propose a high dielectric constant NP0 type dielectric ceramic material and a preparation method and application. The high dielectric constant NP0 type dielectric ceramic material has a high dielectric constant, low dielectric loss and high insulation resistance, and meets the specifications and requirements of NP0 type dielectric ceramics. At the same time, in the process of preparing the dielectric ceramic, the sintering temperature of the BLT system material with a tungsten bronze structure is effectively reduced without adding traditional glass material or sintering aid, and the overall dielectric properties of the ceramic material are optimized.

[0004] Specifically, the high dielectric constant NP0 type dielectric ceramic material provided by the present invention has a dielectric constant of 130 to 140, a dielectric loss of no more than 0.0003, a dielectric constant temperature coefficient of -30ppm / °C to +30ppm / °C, and the dielectric constant temperature coefficient meets the specification requirements of NP0 type dielectric ceramics.

[0005] In one aspect of the present invention, the present invention provides a high dielectric constant NP0 type dielectric ceramic material. According to an embodiment of the present invention, the material is prepared from raw materials containing the following substances: 15 mol% to 16 mol% of BaCO3 and / or BaO, 2 mol% to 6 mol% of Nd2O3, 2 mol% to 6 mol% of Sm2O3, 5 mol% to 10 mol% of Bi2O3, and 55 mol% to 70 mol% of TiO2.

[0006] According to the NP0 type dielectric ceramic material of the above embodiment of the present invention, the raw materials forming the NP0 type dielectric ceramic material include: 15 mol% of BaCO3 and / or BaO, 3 mol% to 6 mol% of Nd2O3, 3 mol% to 6 mol% of Sm2O3, 8.75 mol% of Bi2O3, and 67.5 mol% of TiO2. Thus, the dielectric constant of the NP0 type dielectric ceramic material can be improved while maintaining low dielectric loss.

[0007] By using BaCO3 and / or BaO, Nd2O3, Bi2O3, Sm2O3 and TiO2 to prepare a high dielectric low loss NP0 temperature stable ceramic dielectric material, and controlling the above raw materials within the above addition range, an NP0 type dielectric ceramic material with high dielectric constant, low dielectric loss and high insulation resistance can be prepared. Specifically, the dielectric constant of the high dielectric low loss NP0 temperature stable ceramic dielectric material is 130 to 140, the dielectric loss is not greater than 0.0003, the dielectric constant temperature coefficient is -30ppm / ℃ to +30ppm / ℃, and the dielectric constant temperature coefficient meets the specification requirements of NP0 type dielectric ceramics.

[0008] The present invention also provides a high dielectric constant NP0 type dielectric ceramic material, whose general chemical formula is aBaO-bNd2O3-cSm2O3-dBi2O3-eTiO2, wherein a, b, c, d, and e independently represent mole percentages, wherein a is 15 mol% to 16 mol%, b is 2 mol% to 6 mol%, c is 2 mol% to 6 mol%, d is 5 mol% to 10 mol%, and e is 55 mol% to 70 mol%.

[0009] In another aspect of the present invention, the present invention provides a method for preparing the above-mentioned high dielectric constant low NP0 type dielectric ceramic material. According to an embodiment of the present invention, the method comprises:

[0010] (1) BaCO3 and / or BaO, Nd2O3, Bi2O3, Sm2O3 and TiO2 are mixed, ball-milled and dried to obtain a mixed material;

[0011] (2) pre-burning the mixed material to obtain a pre-burned material;

[0012] (3) mixing the pre-sintered material with a binder, granulating, tableting, and debinding to obtain a ceramic green body;

[0013] (4) Sintering the ceramic green body to obtain the high dielectric constant NP0 type dielectric ceramic material.

[0014] Therefore, the method can be used to prepare NP0 type dielectric ceramic materials with high dielectric constant and low dielectric loss, and the dielectric constant temperature coefficient of the NP0 type dielectric ceramic material is -30ppm / ℃~+30ppm / ℃, which meets the specification requirements of NP0 type dielectric ceramics.

[0015] In addition, the method for preparing the NP0 type dielectric ceramic material according to the above embodiment of the present invention may also have the following technical features:

[0016] In some embodiments of the present invention, in step (1), the rotation speed of the ball mill is 150 r / min to 400 r / min, and the time is 6 h to 24 h.

[0017] In some embodiments of the present invention, in step (1), the drying temperature is 90°C to 200°C.

[0018] In some embodiments of the present invention, in step (2), the pre-firing temperature is 900° C. to 1200° C. and the time is 1 h to 6 h. Thus, the dielectric constant of the NP0 dielectric ceramic material can be increased and the dielectric loss can be reduced.

[0019] In some embodiments of the present invention, in step (2), the heating rate of the pre-calcination is 2° C. / min to 10° C. / min.

[0020] In some embodiments of the present invention, in step (3), the debinding temperature is 500°C to 600°C, the time is 2h to 6h, and the debinding heating rate is 0.5°C / min to 5°C / min. Thus, the binder in the ceramic green body can be removed.

[0021] In some embodiments of the present invention, in step (4), the sintering temperature is 1200° C. to 1280° C. and the sintering time is 3 h to 7 h. Thus, the dielectric constant of the NP0 dielectric ceramic material can be increased and the dielectric loss can be reduced.

[0022] In some embodiments of the present invention, in step (4), the heating rate of the sintering is 2° C. / min to 10° C. / min.

[0023] In another aspect of the present invention, the present invention proposes the application of the above-mentioned high dielectric constant NP0 type dielectric ceramic material or the high dielectric constant NP0 type dielectric ceramic material prepared by the above-mentioned method in the fields of communication, radar or electronics. According to specific embodiments, it can be applied to, including but not limited to, laminated antennas, dielectric antennas, filters and resonators.

[0024] The beneficial effects achieved by the present invention are at least:

[0025] The dielectric constant of the ceramic dielectric material provided by the present invention has a medium sintering temperature, a high dielectric constant, a low dielectric loss and a high insulation resistance. Compared with other NP0 type dielectric materials, this material does not require external sintering aids or modifiers. At the same time, the provided dielectric ceramic material contains a low amount of precious rare earth components, which reduces production costs. Specifically, the provided NP0 type dielectric ceramic material has high dielectric, low loss, and temperature stability, specifically: a dielectric constant of 130 to 140, a dielectric loss of no more than 0.0003, a dielectric constant temperature coefficient of -30ppm / °C to +30ppm / °C, and the dielectric constant temperature coefficient meets the specification requirements of NP0 type dielectric ceramics.

[0026] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below. It should be noted that these embodiments are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0028] The present invention provides a high dielectric constant NP0 type dielectric ceramic material, which is prepared by raw materials containing the following substances:

[0029] 15 mol% to 16 mol% of BaCO3 and / or BaO,

[0030] 2 mol% to 6 mol% Nd2O3,

[0031] 5 mol% to 10 mol% Bi2O3,

[0032] 2 mol% to 6 mol% Sm2O3, and

[0033] 55 mol% to 70 mol% TiO2.

[0034] According to a specific embodiment, the raw materials include: 15 mol% BaCO3 and / or BaO, 3 mol% to 6 mol% Nd2O3, 8.75 mol% Bi2O3, 3 mol% to 6 mol% Sm2O3 and 67.5 mol% TiO2.

[0035] According to a specific implementation, the dielectric constant of the NP0 type dielectric ceramic material is 130 to 140, the dielectric loss is no more than 0.0003, and the dielectric constant temperature coefficient is -30ppm / °C to +30ppm / °C.

[0036] According to a specific embodiment, the general chemical formula of the dielectric ceramic material obtained by the above raw materials is aBaO-bNd2O3-cSm2O3-dBi2O3-eTiO2, wherein a, b, c, d, and e independently represent mole percentages, wherein a is 15 mol% to 16 mol%, b is 2 mol% to 6 mol%, c is 2 mol% to 6 mol%, d is 5 mol% to 10 mol%, and e is 55 mol% to 70 mol%.

[0037] The present invention also proposes a method for preparing the above-mentioned NP0 type dielectric ceramic material, comprising:

[0038] S100: BaCO3 and / or BaO, Nd2O3, Bi2O3, Sm2O3 and TiO2 are mixed, ball-milled and dried

[0039] In this step, BaCO3 and / or BaO, Nd2O3, Bi2O3, Sm2O3 and TiO2 are weighed in molar proportions and mixed evenly, then added into a ball mill for wet ball milling to obtain a uniformly mixed powder, and then the powder is dried to obtain a mixture. It should be noted that ball milling is a conventional operation in the art, and those skilled in the art can select specific parameters of ball milling according to actual conditions, for example, the dispersant used in ball milling includes anhydrous ethanol or high-purity water, and the ball milling medium includes zirconia balls, steel balls, etc.

[0040] According to a specific implementation, the rotation speed of the ball mill is 150 r / min to 400 r / min, and the time is 6 hours to 24 hours. According to a specific implementation, the drying temperature is 90 to 200 degrees Celsius.

[0041] S200: Pre-burning the mixture

[0042] In this step, the mixed material obtained in S100 is pre-fired at a temperature of 900°C to 1200°C (according to a preferred embodiment, 1000°C to 1100°C), the pre-fired time is 1h to 6h, and the pre-fired heating rate is 2°C / min to 10°C / min (according to a preferred embodiment, 4°C / min to 6°C / min), thereby obtaining a pre-fired material. By controlling the pre-fired temperature and time and the pre-fired heating rate, the raw material particles are densified and have a certain reaction activity.

[0043] S300: Mix the pre-burned material with the binder, and then granulate, press and debind.

[0044] In this step, the pre-sintered material obtained in S200 is mixed with a binder, sieved to obtain granules, and the granules are granulated, tableted and debinded to obtain a ceramic green body. According to a specific embodiment, the temperature of debinding is 500°C to 600°C, and the time is 2h to 6h. By debinding, the binder in the ceramic green body can be removed. In combination with the specific embodiment, the heating rate of debinding can be 0.5°C / min to 5°C / min, so that the binder in the ceramic green body can be effectively removed. The binder used includes at least one of a 5wt%-8wt% polyvinyl alcohol aqueous solution and a 5wt%-8wt% polyvinyl butyral ester ethanol solution.

[0045] S400: Sintering the ceramic green body

[0046] In this step, the ceramic green body obtained in S300 is sintered to obtain the NP0 dielectric ceramic material. According to a specific embodiment, the sintering temperature is 1200°C to 1280°C, the time is 3h to 7h, and the sintering heating rate is 2°C / min to 10°C / min.

[0047] Therefore, this method can be used to prepare NP0 type dielectric ceramic materials with high dielectric constant and low dielectric loss, and the dielectric constant temperature coefficient of the NP0 type dielectric ceramic material is -30ppm / ℃~+30ppm / ℃, which meets the specification requirements of NP0 type dielectric ceramics. At the same time, this method effectively reduces the sintering temperature of BLT system materials with tungsten bronze structure without adding traditional glass materials or sintering aids, and optimizes the overall dielectric properties of the ceramic material.

[0048] Application of the above-mentioned NP0 type dielectric ceramic material or the NP0 type dielectric ceramic material prepared by the above-mentioned method in the fields of communication, radar or electronics.

[0049] The present invention is described below with reference to specific examples, which are merely illustrative and do not limit the present invention in any way. Unless otherwise specified, the reagents used in the examples can be obtained commercially.

[0050] Example 1

[0051] Example 1: An NP0 dielectric ceramic material is prepared by the following method, comprising:

[0052] (1) Mix BaCO3 powder, Nd2O3 powder, Bi2O3 powder, Sm2O3 powder and TiO2 powder according to the molar ratio. Among them, the molar ratio of BaCO3 powder is 15%, the molar ratio of Nd2O3 powder is 5.25%, the molar ratio of Bi2O3 powder is 8.75%, the molar ratio of Sm2O3 powder is 3.5%, and the molar ratio of TiO2 powder is 67.5%. Add the weighed raw material powders into the ball mill respectively and perform wet ball milling for 6 hours at a ball mill speed of 300r / min. The uniformly mixed powder is dried at 150 degrees Celsius to obtain a dried mixture;

[0053] (2) pre-calcining the dried mixed material at 1100°C for 3 hours at a heating rate of 5°C / min, and then naturally cooling the pre-calcined mixed powder after keeping the temperature;

[0054] (3) adding a binder (6 wt% polyvinyl alcohol aqueous solution) to the pre-sintered powder, mixing, sieving to obtain granules, granulating, tableting, and debinding the granules, wherein the debinding temperature is 550° C., the debinding time is 2 h, and the debinding heating rate is 3° C. / min to obtain a ceramic green body;

[0055] (4) The obtained ceramic green body was sintered at 1260° C. for 6 h at a sintering heating rate of 5° C. / min to obtain an NP0 type dielectric ceramic material.

[0056] The obtained NP0 dielectric ceramic material is characterized in various ways. After characterizing the material by X-ray diffraction, the chemical formula of the NP0 dielectric ceramic material is 15% BaO-5.25% Nd2O3-3.5% Sm2O3-8.75% Bi2O3-67.5% TiO2.

[0057] Example 2

[0058] Example 2: The NP0 dielectric ceramic material is prepared by the following method, including:

[0059] (1) Mix BaCO3 powder, Nd2O3 powder, Bi2O3 powder, Sm2O3 powder and TiO2 powder according to the molar ratio. Among them, the molar ratio of BaCO3 powder is 15%, the molar ratio of Nd2O3 powder is 4.37%, the molar ratio of Bi2O3 powder is 8.75%, the molar ratio of Sm2O3 powder is 4.37%, and the molar ratio of TiO2 powder is 67.5%. Add the weighed raw material powders into the ball mill respectively and perform wet ball milling for 6 hours at a ball mill speed of 300r / min. The uniformly mixed powder is dried at 150 degrees Celsius to obtain a dried mixture;

[0060] (2) pre-calcining the dried mixed material at 1100°C for 3 hours at a heating rate of 5°C / min, and then naturally cooling the pre-calcined mixed powder after keeping the temperature;

[0061] (3) adding a binder (6 wt% polyvinyl alcohol aqueous solution) to the pre-sintered powder, mixing, sieving to obtain granules, granulating, tableting, and debinding the granules, wherein the debinding temperature is 550° C., the debinding time is 2 h, and the debinding heating rate is 3° C. / min to obtain a ceramic green body;

[0062] (4) The obtained ceramic green body was sintered at 1260° C. for 6 h at a sintering heating rate of 5° C. / min to obtain an NP0 type dielectric ceramic material.

[0063] After characterizing the material through X-ray diffraction, the chemical formula of the mentioned NP0 type dielectric ceramic material is 15% BaO-4.37% Nd2O3-4.37% Sm2O3-8.75% Bi2O3-67.5% TiO2.

[0064] Example 3

[0065] Example 3: The NP0 dielectric ceramic material is prepared by the following method, including:

[0066] (1) Mix BaCO3 powder, Nd2O3 powder, Bi2O3 powder, Sm2O3 powder and TiO2 powder according to the molar ratio. Among them, the molar ratio of BaCO3 powder is 15%, the molar ratio of Nd2O3 powder is 3.5%, the molar ratio of Bi2O3 powder is 8.75%, the molar ratio of Sm2O3 powder is 5.25%, and the molar ratio of TiO2 powder is 67.5%. Add the weighed raw material powders into the ball mill respectively and perform wet ball milling for 6 hours at a ball mill speed of 300r / min. The uniformly mixed powder is dried at 150 degrees Celsius to obtain a dried mixture;

[0067] (2) pre-calcining the dried mixed material at 1100°C for 3 hours at a heating rate of 5°C / min, and then naturally cooling the pre-calcined mixed powder after keeping the temperature;

[0068] (3) adding a binder (6 wt% polyvinyl alcohol aqueous solution) to the pre-sintered powder, mixing, sieving to obtain granules, granulating, tableting, and debinding the granules, wherein the debinding temperature is 550° C., the debinding time is 2 h, and the debinding heating rate is 3° C. / min to obtain a ceramic green body;

[0069] (4) The obtained ceramic green body was sintered at 1240° C. for 6 h at a sintering heating rate of 5° C. / min to obtain an NP0 type dielectric ceramic material.

[0070] After characterizing the material through X-ray diffraction, the chemical formula of the mentioned NP0 type dielectric ceramic material is 15% BaO-3.5% Nd2O3-5.25% Sm2O3-8.75% Bi2O3-67.5% TiO2.

[0071] Comparative Example 1

[0072] Comparative Example 1: The NP0 dielectric ceramic material is prepared by the following method. The main differences between Comparative Example 1 and Example 1 are as follows:

[0073] (1) BaCO3 powder, Nd2O3 powder and TiO2 powder are mixed according to a molar ratio, wherein the molar ratio of BaCO3 powder is 15%, the molar ratio of Nd2O3 powder is 17.5%, and the molar ratio of TiO2 powder is 67.5%.

[0074] (4) The obtained ceramic green body was sintered at 1340°C for 6 h, with a sintering heating rate of 5°C / min.

[0075] After characterizing the material through X-ray diffraction, the chemical formula of the mentioned NP0 type dielectric ceramic material is 15% BaO-17.5% Nd2O3-67.5% TiO2.

[0076] Comparative Example 2

[0077] Comparative Example 2: The NP0 dielectric ceramic material is prepared by the following method. The main differences between Comparative Example 2 and Example 1 are as follows:

[0078] (1) BaCO3 powder, Nd2O3 powder, Bi2O3 powder and TiO2 powder are mixed according to a molar ratio, wherein the molar ratio of BaCO3 powder is 15%, the molar ratio of Nd2O3 powder is 8.75%, the molar ratio of Bi2O3 powder is 8.75%, and the molar ratio of TiO2 powder is 67.5%.

[0079] (4) The obtained ceramic green body was sintered at 1260°C for 6 h, with a sintering heating rate of 5°C / min.

[0080] After characterizing the material through X-ray diffraction, the chemical formula of the NP0 type dielectric ceramic material mentioned is 15% BaO-8.75% Nd2O3-8.75% Bi2O3-67.5% TiO2.

[0081] Comparative Example 3

[0082] Comparative Example 3: The NP0 dielectric ceramic material is prepared by the following method. The main differences between Comparative Example 3 and Example 1 are as follows:

[0083] (1) BaCO3 powder, Nd2O3 powder, Bi2O3 powder, Sm2O3 powder and TiO2 powder are mixed according to a molar ratio. The molar ratio of BaCO3 powder is 15%, the molar ratio of Nd2O3 powder is 7%, the molar ratio of Sm2O3 powder is 1.75%, the molar ratio of Bi2O3 powder is 8.75%, and the molar ratio of TiO2 powder is 67.5%.

[0084] (4) The obtained ceramic green body was sintered at 1240°C for 6 h with a sintering heating rate of 5°C / min.

[0085] After characterizing the material through X-ray diffraction, the chemical formula of the mentioned NP0 type dielectric ceramic material is 15% BaO-7% Nd2O3-1.75% Sm2O3-8.75% Bi2O3-67.5% TiO2.

[0086] The composition and dosage of the high dielectric constant NP0 type dielectric ceramic materials of the above-mentioned Examples 1-5 and Comparative Examples 1-2 are summarized in Table 1.

[0087] Table 1

[0088]

[0089] The properties of the ceramic materials obtained in Examples 1-3 and Comparative Examples 1-3 were measured.

[0090] The ceramic material is tested for performance at 1V and 1MHz, including the dielectric constant, dielectric loss at 25℃, insulation resistivity at 25℃, insulation resistivity at 125℃, and dielectric temperature coefficient (TCC).

[0091] The dielectric constant, dielectric loss at 25°C, insulation resistivity at 25°C, and insulation resistivity at 125°C were all measured using methods known in the prior art, i.e., coating silver electrodes on both sides of the ceramic to conduct electrical performance tests;

[0092] The dielectric constant temperature coefficient TCC represents the degree of change of the capacitance of the material with temperature. It is calculated by testing the capacitance value at a temperature of -55℃ to 125℃ and using the following formula:

[0093]

[0094] Among them, T0 is the target test temperature.

[0095] The specific measurement results are shown in Table 2.

[0096] Table 2

[0097]

[0098]

[0099] It can be seen from Table 2 that the dielectric ceramic of Example 1 has a larger dielectric constant and a smaller dielectric loss, and the dielectric constant temperature coefficient is -30ppm / °C to +30ppm / °C, and the dielectric constant temperature coefficient meets the requirements of the NP0 type dielectric ceramic specification. This shows that the dielectric ceramic prepared by the present invention has a high dielectric constant, low dielectric loss and high insulation resistance.

[0100] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "implementation", "specific implementation", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0101] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A high dielectric constant NP0 type dielectric ceramic material, characterized in that: Prepared from raw materials containing the following substances: 15 mol% to 16 mol% of BaCO3 and / or BaO, 2 mol% to 6 mol% Nd2O3, 2 mol% to 6 mol% Sm2O3, 5 mol% to 10 mol% Bi2O3, and 55 mol % to 70 mol % TiO2.

2. The high dielectric constant NP0 type dielectric ceramic material according to claim 1, characterized in that: The raw materials for forming the NP0 type dielectric ceramic include: 15 mol % of BaCO3 and / or BaO, 3 mol% to 6 mol% Nd2O3, 3 mol% to 6 mol% Sm2O3, 8.75 mol% Bi2O3, and 67.5 mol% TiO2.

3. A high dielectric constant NP0 type dielectric ceramic material, characterized in that: The chemical formula of the NP0 type dielectric ceramic material is aBaO-bNd2O3-cSm2O3-dBi2O3-eTiO2, wherein a, b, c, d, and e represent molar percentages independently. wherein a is 15 mol% to 16 mol%, b is 2 mol% to 6 mol%, c is 2 mol% to 6 mol%, d is 5 mol% to 10 mol%, and e is 55 mol% to 70 mol%.

4. The high dielectric constant NP0 type dielectric ceramic material according to any one of claims 1 to 3, characterized in that: The dielectric constant of the NP0 type dielectric ceramic material is 130-140, the dielectric loss is not greater than 0.0003, and the dielectric constant temperature coefficient is -30ppm / °C to +30ppm / °C.

5. A method for preparing the high dielectric constant NP0 type dielectric ceramic material according to any one of claims 1 to 4, characterized in that: include: (1) BaCO3 and / or BaO, Nd2O3, Bi2O3, Sm2O3 and TiO2 are mixed, ball-milled and dried to obtain a mixed material; (2) pre-burning the mixed material to obtain a pre-burned material; (3) mixing the pre-sintered material with a binder, granulating, tableting and debinding to obtain a ceramic green body; (4) Sintering the ceramic green body to obtain the high dielectric constant NP0 type dielectric ceramic material.

6. The method according to claim 5, characterized in that In step (1), the rotation speed of the ball mill is 150 r / min to 400 r / min, and the time is 6 h to 24 h; Optionally, the drying temperature is 90°C to 200°C.

7. The method according to claim 5, characterized in that In step (2), the pre-burning temperature is 900° C. to 1200° C., and the time is 1 h to 6 h; Optionally, the heating rate of the pre-calcination is 2°C / min to 10°C / min.

8. The method according to claim 5, characterized in that In step (3), the debinding temperature is 500°C to 600°C, and the time is 2h to 6h; Optionally, the heating rate of the debinding process is 0.5°C / min to 5°C / min.

9. The method according to claim 5, characterized in that In step (4), the sintering temperature is 1200° C. to 1280° C., and the sintering time is 3 h to 7 h; Optionally, in step (4), the heating rate of the sintering is 2°C / min to 10°C / min.

10. Use of the high dielectric constant NP0 type dielectric ceramic material according to any one of claims 1 to 4 or the high dielectric constant NP0 type dielectric ceramic material prepared by the method according to any one of claims 5 to 9 in the fields of communication, radar or electronics.

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