A microwave dielectric ceramic material and its preparation method and application

Abstract

The present invention belongs to the technical field of capacitor devices, and specifically relates to a microwave dielectric ceramic material and its preparation method and application. The microwave dielectric ceramic material provided by the present invention comprises the following raw materials in percentage by weight: 46.99-91.98 wt% Mg2(Si 0.08 Ti 0.92 )O4, 0.39~38.45wt%Ba 6‑3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 , 0.86-1.96 wt% sintering aid and 0.08-19.77 wt% modifying additive, where 0.5≤x≤0.7. The microwave dielectric ceramic material provided by the present invention has high insulation resistivity and meets the AG temperature coefficient requirements of GB 5596 within the temperature range of -55-125°C. It can be used to prepare single-layer ceramic capacitors with a wide capacitance range and AG characteristics.

Description

Technical Field

[0001] The present invention belongs to the technical field of capacitor devices, and in particular relates to a microwave dielectric ceramic material and a preparation method and application thereof. Background Art

[0002] With the rapid development of electronic information technology, the requirements for the integration, reliability, stability, and miniaturization of electronic components are becoming increasingly stringent. Today, fifth-generation (5G) communication networks have been widely deployed, and information technology is developing towards higher frequencies, higher powers, greater integration, and greater multifunctionality.

[0003] Single-layer chip ceramic capacitors are ceramic capacitors developed to meet the requirements of high frequency, high integration, miniaturization, low power consumption and high reliability of electronic components. Compared with multi-layer chip ceramic capacitors (MLCCs), single-layer chip ceramic capacitors have fewer electrode layers and use sputtered metal as the electrode structure of the external electrode. Therefore, they have lower equivalent series resistance, higher quality factor and higher reliability under high frequency and microwave conditions. Single-layer chip ceramic capacitors are mainly used in microwave integrated circuits (MICs) such as microwave communications, power amplifiers, and transmitters for DC isolation, bypass, coupling, tuning, impedance matching or coplanar waveguides. The capacitance of a conventional single-layer chip ceramic capacitor is C = 0.0885εS / d. The overlap area of ​​the electrodes S (cm 2 ) and the dielectric thickness d(cm) are fixed, the capacitance of the capacitor is mainly designed by the dielectric constant ε of the dielectric. However, the dielectric constants of existing microwave dielectric ceramics that meet AG characteristics are mostly below 10 or above 90, which limits the application scope of single-layer chip ceramic capacitors and ceramic substrates. Summary of the Invention

[0004] In view of this, the present invention provides a microwave dielectric ceramic material, a preparation method and application thereof. The capacitor prepared using the microwave dielectric ceramic material provided by the present invention has a wider range of capacitance, thereby expanding the application range of single-layer chip ceramic capacitors.

[0005] In order to solve the above technical problems, the present invention provides a microwave dielectric ceramic material, comprising the following raw materials in percentage by mass:

[0006]

[0007]

[0008] Among them, 0.5≤x≤0.7.

[0009] Preferably, the sintering aid is one or more of B2O3, SiO2 and ZnO.

[0010] Preferably, the modifying additive is a manganese compound, an aluminum compound or a cobalt compound;

[0011] The manganese compound is manganese oxide and / or manganese carbonate;

[0012] The aluminum compound is aluminum oxide and / or aluminum carbonate;

[0013] The cobalt compound is cobalt oxide and / or cobalt carbonate.

[0014] Preferably, the Mg2(Si 0.08 Ti 0.92 )O4 preparation method comprises the following steps:

[0015] Mg(OH)2, TiO2 and SiO2 are mixed and calcined to obtain the Mg2(Si 0.08 Ti 0.92 )O4.

[0016] Preferably, the calcination temperature is 1050-1150° C., and the calcination holding time is 2-5 hours.

[0017] Preferably, the Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 The preparation method comprises the following steps:

[0018] BaCO3, Sm2O3, ZrO2 and TiO2 are mixed and calcined to obtain the Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 .

[0019] Preferably, the calcination temperature is 1070-1200° C., and the calcination holding time is 2-4 hours.

[0020] The present invention also provides a method for preparing the microwave dielectric ceramic material described in the above technical solution, comprising the following steps:

[0021] Mg2(Si 0.08 Ti 0.92 )O4、Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 , a sintering aid and a modifying additive are mixed to obtain the microwave dielectric ceramic material.

[0022] Preferably, the mixing is carried out under ball milling conditions;

[0023] The ball milling speed is 300-400 r / min, and the ball milling time is 5-10 h.

[0024] The present invention also provides the use of the microwave dielectric ceramic material described in the above technical solution or the microwave dielectric ceramic material prepared by the preparation method described in the above technical solution in the preparation of ceramic capacitors.

[0025] The present invention provides a microwave dielectric ceramic material, comprising the following raw materials in percentage by weight: 46.99-91.98 wt% Mg2(Si 0.08 Ti 0.92 )O4, 0.39~38.45wt%Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 , 0.86-1.96wt% sintering aid and 0.08-19.77wt% modifying additive, wherein 0.5≤x≤0.7. The microwave dielectric ceramic material provided by the present invention has a high insulation resistivity, meets the requirements of the AG temperature coefficient in GB 5596 within the temperature range of -55-125°C, and can be used to prepare single-layer chip ceramic capacitors with AG characteristics. The microwave dielectric ceramic material provided by the present invention has a wide range of dielectric constants (12-38), and the single-layer chip ceramic capacitors prepared using the microwave dielectric ceramic material provided by the present invention have a wide range of capacitance, which expands the application range of the capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of a single-layer chip ceramic capacitor made from the microwave dielectric ceramic material in Table 1. The yellow part is the metal layer. DETAILED DESCRIPTION

[0027] The present invention provides a microwave dielectric ceramic material comprising the following raw materials in percentage by mass:

[0028]

[0029] Among them, 0.5≤x≤0.7.

[0030] In the present invention, unless otherwise specified, all raw materials used are conventional commercially available products.

[0031] In the present invention, the raw materials for preparing the microwave dielectric ceramic material include 46.99-91.98 wt% Mg2(Si 0.08 Ti 0.92)O4, preferably 50 to 85 wt%, more preferably 60 to 75 wt%, and even more preferably 65 to 70%. In the present invention, the Mg2(Si 0.08 Ti 0.92 )O4 preparation method preferably comprises the following steps:

[0032] Mg(OH)2, TiO2 and SiO2 are mixed and calcined to obtain the Mg2(Si 0.08 Ti 0.92 )O4.

[0033] In the present invention, the purity of the Mg(OH)2 is preferably 99% or higher, more preferably 99.5 to 99.8%. In the present invention, the purity of the TiO2 is preferably 99% or higher, more preferably 99.1 to 99.9%. In the present invention, the purity of the SiO2 is preferably 99% or higher, more preferably 99.1 to 99.8%.

[0034] In the present invention, the mixing is preferably wet ball milling. In the present invention, the solvent for wet ball milling is preferably deionized water or pure water, more preferably pure water. In the present invention, the wet ball milling is preferably planetary ball milling, and the rotation speed of the planetary ball mill is preferably 300-400 r / min, more preferably 350-380 r / min; the time of the planetary ball milling is preferably 4-6 hours, more preferably 5 hours. In the present invention, after the mixing, it is preferably further included: drying and sieving the mixture obtained by the mixing in sequence. In the present invention, the drying temperature is preferably 110-130°C, more preferably 120°C. In the present invention, the aperture of the sieve for screening is preferably 60 mesh. In the present invention, when there is oversize during screening, it is preferred to continue grinding and sieving the oversize until all the materials become undersize.

[0035] In the present invention, the calcination temperature is preferably 1050-1150° C., more preferably 1080-1130° C.; the calcination holding time is preferably 2-5 hours, more preferably 3-4 hours.

[0036] In the present invention, the Mg2(Si 0.08 Ti 0.92 )O4 includes Mg2TiO4 and Mg2SiO4; the molar ratio of Mg2TiO4 to Mg2SiO4 is 0.92:0.08. Large grains of Mg2TiO4 phase in microwave dielectric ceramic material will affect the reliability of microwave dielectric ceramic material, thereby reducing its insulation resistivity and increasing its dielectric loss. Large grains of Mg2TiO4 phase will also reduce the mechanical strength of microwave dielectric ceramic material, affect the qualified rate of grinding process, and thus affect the preparation of single-layer chip ceramic capacitor. In the present invention, the Mg2(Si 0.08Ti 0.92 )O4 contains Si, which can broaden the sintering temperature and inhibit the abnormal growth of Mg2TiO4; the microwave dielectric ceramic material provided by the present invention has high reliability and mechanical strength.

[0037] In the present invention, the raw materials for preparing the microwave dielectric ceramic material include 0.39-38.45 wt% Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 , preferably 1.5 to 30 wt%, more preferably 4 to 25 wt%, and even more preferably 8 to 15 wt%. In the present invention, the x satisfies 0.5≤x≤0.7, preferably 0.6≤x≤0.67. In the present invention, the Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 The preparation method preferably comprises the following steps:

[0038] BaCO3, Sm2O3, ZrO2 and TiO2 are mixed and calcined to obtain the Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 .

[0039] In the present invention, the purity of the BaCO3 is preferably 99% or higher, more preferably 99.5-99.8%. In the present invention, the purity of the Sm2O3 is preferably 99% or higher, more preferably 99.1-99.6%. In the present invention, the purity of the ZrO2 is preferably 99% or higher, more preferably 99.2-99.9%. In the present invention, the purity of the TiO2 is preferably 99% or higher, more preferably 99.1-99.9%.

[0040] In the present invention, the mixing is preferably wet ball milling. In the present invention, the solvent used in the wet ball milling is preferably deionized water or pure water, more preferably pure water. In the present invention, the wet ball milling is preferably planetary ball milling, with the rotational speed of the planetary ball mill preferably being 300-400 rpm, more preferably 350-380 rpm; and the planetary ball milling time is preferably 4-6 hours, more preferably 5 hours. Ball milling in the present invention enables uniform mixing of materials and refinement of the materials.

[0041] In the present invention, after the mixing, the process preferably further comprises drying and sieving the mixture. In the present invention, the drying temperature is preferably 110-130°C, more preferably 120°C. In the present invention, the sieve mesh preferably has a 60-mesh aperture. In the present invention, if oversize material is present during sieving, the oversize material is preferably further ground and sieved until all the material becomes undersize material.

[0042] In the present invention, the calcination temperature is preferably 1070-1200° C., more preferably 1100-1150° C.; the calcination holding time is preferably 2-4 h, more preferably 2.5-3.5 h.

[0043] In the present invention, Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 The dielectric constant is around 80, and the frequency temperature coefficient τ f In (-16.5~-11.3)×10 -6 / ℃ range; while Mg2(Si 0.08 Ti 0.92 )O4 has a dielectric constant of 14 and a frequency temperature coefficient τ f -50×10 -6 / ℃,Mg2(Si 0.08 Ti 0.92 )O4 has a dielectric constant of 6.8 and a frequency temperature coefficient τ f -67×10 -6 / ℃. Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 While improving the system structure of microwave dielectric ceramic materials and widening the sintering temperature of microwave dielectric ceramic materials, the dielectric constant thereof can be adjusted and the temperature coefficient can be improved.

[0044] In the present invention, the raw materials for preparing the microwave dielectric ceramic material include, by weight percentage, 0.86-1.96 wt% sintering aid, preferably 0.94-1.63 wt%, and more preferably 1-1.28 wt%. In the present invention, the sintering aid is preferably one or more of B2O3, SiO2, and ZnO, more preferably B2O3, SiO2, or ZnO. In the present invention, when the sintering aid includes two or more of the above-mentioned specific substances, the present invention has no specific requirements for the ratio of the specific substances; any ratio can be used. In the embodiments of the present invention, a mixture of B2O3, SiO2, and ZnO in a molar ratio of 3:2:5 is used as the sintering aid.

[0045] In the present invention, the sintering aid effectively diffuses into the grain boundary layer, effectively improving the dielectric properties and ceramic strength of the microwave dielectric ceramic material. If the addition amount is too low, the ceramic will be underfired and the insulation resistance will decrease; if the addition amount is too high, the dielectric loss will be too high and the ceramic strength will be low. In the present invention, the sintering aid forms a liquid phase during the sintering process. The migration rate of liquid phase species is much faster than the diffusion rate of solid phase species, thereby accelerating the particle rearrangement and mass transfer process, allowing the green body to obtain a dense sintered body at a temperature much lower than the solid phase sintering temperature.

[0046] In the present invention, the raw materials for preparing the microwave dielectric ceramic material include, by weight percentage, 0.08 to 19.77 wt% of a modifying additive, preferably 5.2 to 16.69 wt%, and more preferably 13.21 to 13.92 wt%. In the present invention, the modifying additive is preferably one or more of a manganese compound, an aluminum compound, and a cobalt compound, more preferably a manganese compound, an aluminum compound, and a cobalt compound. In the present invention, the manganese compound is preferably manganese oxide and / or manganese carbonate, more preferably manganese oxide. In the present invention, the manganese oxide is preferably MnO and / or MnO2. In the present invention, the aluminum compound is preferably aluminum oxide and / or aluminum carbonate, more preferably aluminum oxide; the aluminum oxide is preferably Al2O3. In the present invention, the cobalt compound is preferably cobalt oxide and / or cobalt carbonate, more preferably cobalt oxide. In the present invention, the cobalt oxide is preferably CoO.

[0047] In the present invention, the modifying additives are preferably MnO, Al2O3, and CoO. The mass percentage of MnO in the microwave dielectric ceramic material is preferably 0.08-1.96 wt%, more preferably 0.16-0.26 wt%. The mass percentage of Al2O3 in the microwave dielectric ceramic material is preferably 4.69-19.77 wt%, more preferably 12.82-16.33 wt%. The mass percentage of CoO in the microwave dielectric ceramic material is preferably 0.12-0.30 wt%, more preferably 0.17-0.23 wt%. In the present invention, MnO can ensure that the capacitor has low dielectric loss under microwave conditions and improve the Q value of the capacitor. When the MnO content is too low, the dielectric loss of the capacitor under microwave conditions increases, and the capacitor is prone to heat failure. When the MnO content is too high, the ceramic structure becomes loose and the dielectric properties are poor. In the present invention, Al2O3 improves the sintering characteristics of the ceramic body, enhances its mechanical strength, and improves its dielectric properties. Too little addition results in poor mechanical strength and high dielectric loss, while too much makes sintering difficult. In the present invention, CoO improves and increases the insulation resistance of the capacitor and effectively reduces dielectric loss. Too little addition negatively impacts the insulation resistance, while too much makes sintering difficult.

[0048] In the present invention, the dielectric constant of the microwave dielectric ceramic material is preferably 12 to 38; the insulation resistivity of the microwave dielectric ceramic material is preferably >1×10 13 Ω·cm.

[0049] In the present invention, the microwave dielectric ceramic material can be used in microwave devices such as multilayer chip ceramic capacitors, single-layer chip ceramic capacitors, and microwave substrates.

[0050] The present invention also provides a method for preparing the microwave dielectric ceramic material described in the above technical solution, comprising the following steps:

[0051] Mg2(Si 0.08 Ti 0.92 )O4、Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 , a sintering aid and a modifying additive are mixed to obtain the microwave dielectric ceramic material.

[0052] In the present invention, the mixing step preferably further includes: sequentially grinding, drying, screening, and calcining the sintering aid. In the present invention, the grinding step is preferably ball milling. In the present invention, the ball milling solvent is preferably water, preferably deionized water; the ball milling speed is preferably 300-400 rpm, more preferably 350 rpm; and the ball milling time is preferably 3-6 hours. In the present invention, the drying temperature is preferably 60-80°C. The present invention has no particular requirements for the drying time, as long as it can remove moisture from the surface of the material.

[0053] In the present invention, the calcination temperature is preferably 550-650°C, more preferably 580-600°C; the calcination holding time is preferably 2-4 hours, more preferably 2.5-3.5 hours. In the present invention, the sintering aids (B2O3 and SiO2 powders) are highly hygroscopic. The purpose of calcination is to form a semi-finished product at a relatively low temperature and remove any water of crystallization present in the materials. Calcination can induce interactions between the components of the mixture through ion interdiffusion and control sample shrinkage. The desired final phase may not be fully formed, but the continued chemical gradient can promote sintering. In the present invention, the mixing is preferably performed under ball milling conditions. In the present invention, the ball milling speed is preferably 300-400 rpm, more preferably 330-350 rpm; the ball milling time is preferably 5-10 hours, more preferably 6-8 hours. In the present invention, the ball milling is preferably wet milling, and the solvent used for wet milling is preferably water, more preferably deionized water. In the present invention, the ball milling balls are preferably zirconium balls.

[0054] In the present invention, after mixing, the further step of drying the mixture and then filtering it through a 100-mesh sieve is preferably performed. In the present invention, the drying step is preferably oven drying, and the oven drying temperature is preferably 110-130°C, more preferably 115-120°C; the oven drying time is preferably 5-7 hours, more preferably 6 hours. The preparation method provided by the present invention is simple, easily mass-produced, has low raw material costs, and is environmentally friendly.

[0055] The present invention uses Mg2(Si 0.08 Ti 0.92 )O4 as the basis, by adjusting Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 , the amount of modified additives to adjust the dielectric properties and microstructure so that it complies with the AG temperature coefficient (temperature coefficient α c At (100±30)×10 -6 / ℃) requirements; and the prepared microwave dielectric ceramic material has a high insulation resistivity (>10 13 Ω·cm).

[0056] The present invention also provides the use of the microwave dielectric ceramic material described in the above technical solution or the microwave dielectric ceramic material prepared by the preparation method described in the above technical solution in the preparation of ceramic capacitors. In the present invention, the ceramic capacitor preferably includes a multilayer chip ceramic capacitor or a single-layer ceramic capacitor. In the present invention, the single-layer ceramic capacitor is preferably a single-layer chip ceramic capacitor; the single-layer chip ceramic capacitor preferably includes a block made by sintering a microwave dielectric ceramic material and a conductive layer coated on the surface of the microwave dielectric ceramic material; the microwave dielectric ceramic material is the microwave dielectric ceramic material described in the above technical solution or the microwave dielectric ceramic material prepared by the preparation method described in the above technical solution.

[0057] In the present invention, the conductive layer of the single-layer chip ceramic capacitor is a gold layer.

[0058] The present invention has no special requirements for the preparation method of the single-layer chip ceramic capacitor, and conventional methods in the art can be used.

[0059] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0060] Example 1

[0061] (1)Mg2(Si 0.08 Ti0.92 Preparation of )O4

[0062] Mg(OH)2 with a purity of 99.5%, TiO2 with a purity of 99.8%, SiO2 with a purity of 99.5% and Mg2(Si 0.08 Ti 0.92 )O4 in a planetary ball mill at a speed of 350 r / min (using pure water as solvent and zirconium balls as grinding balls) for 5 h; the ball-milled mixture was dried at 120°C and passed through a 60-mesh sieve; the sieved mixture (sieve residue) was calcined at 1100°C for 4 h to obtain Mg2(Si 0.08 Ti 0.92 )O4;

[0063] (2)Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 Preparation of (x is 0.67)

[0064] BaCO3 with a purity of 99.8%, Sm2O3 with a purity of 99.5%, ZrO2 with a purity of 99.8%, and TiO2 with a purity of 99.8% are mixed into a mixture of Ba4Sm 9.34 Ti 17.95 Zr 0.05 O 54 The ingredients were prepared according to the molar ratio, and ball milled in a planetary ball mill at a speed of 350 r / min (using deionized water as solvent and zirconium balls as grinding balls) for 5 h; the ball-milled mixture was dried at 120 ° C and passed through a 60-mesh sieve; the sieved mixture (sieve underfill) was calcined at 1150 ° C for 3 h to obtain Ba 3.99 Sm 9.34 Ti 17.95 Zr 0.05 O 54 ;

[0065] (3) Treatment of sintering aids

[0066] B2O3, SiO2, and ZnO, all with a purity of more than 99%, were ball-milled in a planetary ball mill at a molar ratio of 3:2:5 at a speed of 350 r / min (using deionized water as the solvent and zirconium balls as the grinding balls) for 5 hours, then dried at 70°C, passed through a 100-mesh sieve, and calcined at 600°C for 4 hours.

[0067] (4) Preparation of microwave dielectric ceramic materials

[0068] Mg2(Si 0.08 Ti 0.92 )O4、Ba3.99 Sm 9.34 Ti 17.95 Zr 0.05 O 54 The sintering aid and the modified additive after heat preservation treatment (a mixture of MnO, Al2O3 and CoO with a mass ratio of 0.08:19.57:012) are mixed in a ratio of 77.89:0.391.96:19.77 and ball milled in a planetary ball mill at a speed of 350 r / min (with deionized water as solvent and zirconium balls as grinding balls) for 5 hours. After drying at 120°C for 6 hours, the mixture is passed through a 100-mesh sieve and the sieve underflow is taken to obtain the microwave dielectric ceramic material; when sieving, the sieve overflow is further ground and sieved until there is no sieve overflow.

[0069] Examples 2 to 17

[0070] The microwave dielectric ceramic material was prepared according to the method of Example 1, with the differences referred to Table 1.

[0071] Table 1 Ratio of raw materials for preparing microwave dielectric ceramic materials in Examples 1 to 17

[0072]

[0073] The microwave dielectric materials prepared in Examples 1 to 17 and 10 wt % PVB (polyvinyl butyral) solution were respectively bonded and granulated, and then pressed into discs at a pressure of 4 MPa to obtain green bodies; the green bodies were debinded at a debinding temperature of 450° C., a heating rate of 3° C. / min, and a holding temperature of 3 h to remove the adhesive; the debinded green bodies were sintered at 1300° C., held for 2 h, and naturally cooled to room temperature in the furnace; silver paste was coated on both surfaces of the discs and silver electrodes were fired; the dielectric constant, dielectric loss, insulation resistivity, and capacitance temperature coefficient of the microwave dielectric ceramic materials prepared in Examples 1 to 17 were tested in accordance with GB5596 "Ceramic Dielectric Materials for Capacitors", and the results are listed in Table 2.

[0074] Table 2 Performance parameters of microwave dielectric ceramic materials prepared in Examples 1 to 17

[0075]

[0076] As can be seen from Table 2, the microwave dielectric ceramic material provided by the present invention has a wide range of dielectric constants, small dielectric loss, and good insulation resistivity, and can be used to prepare single-layer chip ceramic capacitors with AG characteristics.

[0077] The microwave dielectric ceramic materials in Table 1 were processed through conventional process flow such as tape casting → lamination → lamination and cutting → binder removal → sintering → sputtering → electroplating → cutting to prepare single-layer chip ceramic capacitors. The structural diagram of the prepared single-layer chip ceramic capacitor is shown in the figure. Figure 1 As shown in Table 3, L represents the length of the single-layer ceramic chip capacitor, W represents the width of the single-layer ceramic chip capacitor, and T represents the height of the single-layer ceramic chip capacitor. The prepared single-layer ceramic chip capacitor was tested according to GJB 2442A, "General Specification for Single-Layer Ceramic Chip Capacitors with Failure Rate Grades." The resulting performance is listed in Table 3.

[0078] Table 3 Sample size and dielectric properties of single-layer ceramic capacitors prepared in Examples 1 to 17

[0079]

[0080] It can be seen from Table 3 that the capacitance C of a conventional single-layer ceramic capacitor is 0.0885εS / d. When the electrode overlap area S (cm2) and the dielectric thickness d (cm) are fixed, the capacitance of the capacitor is mainly designed by the dielectric constant ε of the dielectric. This solves the problem that the dielectric constant of existing microwave dielectric ceramics with AG characteristics is mostly below 10 or above 90, and the capacitance range of single-layer ceramic capacitors is narrow.

[0081] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A microwave dielectric ceramic material, characterized in that: Including the following raw materials in percentage by mass: Among them, 0.5≤x≤0.7; The sintering aid is one or more of B2O3, SiO2 and ZnO; The dielectric constant of the microwave dielectric ceramic material is 12-38.

2. The microwave dielectric ceramic material according to claim 1, characterized in that: The modifying additive is a manganese compound, an aluminum compound or a cobalt compound; The manganese compound is manganese oxide and / or manganese carbonate; The aluminum compound is aluminum oxide and / or aluminum carbonate; The cobalt compound is cobalt oxide and / or cobalt carbonate.

3. The microwave dielectric ceramic material according to claim 1, characterized in that: The Mg2(Si 0.08 Ti 0.92 )O4 preparation method The following steps are involved: Mg(OH)2, TiO2 and SiO2 are mixed and calcined to obtain the Mg2(Si 0.08 Ti 0.92 )O4.

4. The microwave dielectric ceramic material according to claim 3, characterized in that: The calcination temperature is 1050-1150° C., and the calcination holding time is 2-5 hours.

5. The microwave dielectric ceramic material according to claim 1, characterized in that: The Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 The preparation method comprises the following steps: BaCO3, Sm2O3, ZrO2 and TiO2 are mixed and calcined to obtain the Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 .

6. The microwave dielectric ceramic material according to claim 5, characterized in that: The calcination temperature is 1070-1200° C., and the calcination holding time is 2-4 hours.

7. The method for preparing the microwave dielectric ceramic material according to any one of claims 1 to 6, comprising the following steps: Mg2(Si 0.08 Ti 0.92 )O4、Ba 6-3x Sm 8+2x Ti 17.95 Zr 0.05 O 54 , a sintering aid and a modifying additive are mixed to obtain the microwave dielectric ceramic material.

8. The preparation method according to claim 7, characterized in that: The mixing is carried out under ball milling conditions; The ball milling speed is 300-400 r / min, and the ball milling time is 5-10 h.

9. Use of the microwave dielectric ceramic material according to any one of claims 1 to 6 or the microwave dielectric ceramic material prepared by the preparation method according to claim 7 or 8 in the preparation of ceramic capacitors.

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