A reduction-resistant microwave temperature-stabilized ceramic capacitor, its ceramic dielectric material, and its preparation method.

Abstract

A reduction-resistant microwave temperature-stabilized ceramic capacitor, its ceramic dielectric material, and its preparation method are disclosed. The ceramic dielectric material is composed of 100 moles of Ba. x Sr 1‑x Mo 1‑y W y Using O4 as a base material, the following components are added in molar amounts: 4-8 parts of CaRe4(MoO4)6, 2-5 parts of BiYMoO6, 0.5-1.0 parts of MgAl₂O₄, 0.2-0.8 parts of ZrSiO₄, and 1-3 parts of Na₂B₂O₇, wherein 0 < x < 0.15, 0 < y < 0.10, and Re = La, Nd, Ce; This invention uses Ba x Sr 1‑x Mo 1‑y W y Using O4 as the base material, CaRe4(MoO4)6 and BiYMoO6 synthesized by solid-state method were added to improve its dielectric constant and adjust the temperature coefficient of capacitance. Spinel MgAl2O4 and zircon ZrSiO4 were used to improve the dielectric material's resistance to reduction under N2 / H2 atmosphere, and borax Na2B2O7 was added to lower its densification temperature. The resulting ceramic dielectric has a dielectric constant of [missing information]. e r With a temperature >80 and a densification temperature between 1150 and 1250°C, it is suitable for use as a reduction-resistant microwave temperature-stabilized ceramic capacitor with nickel as the internal electrode.

Description

Technical Field

[0001] This invention belongs to the field of ceramic capacitor preparation, specifically relating to a reduction-resistant microwave temperature-stable ceramic capacitor, its ceramic dielectric material, and preparation method. Background Technology

[0002] Based on the different dielectric constants of microwave dielectric ceramic dielectric materials, they can be classified into low dielectric constants and high dielectric constants. e r kind( e r <40), Middle e r Class (40 ≤ e r ≤ 80), High e r kind( e r >80) Three categories, among which, high e r Microwave-like dielectric ceramics are mainly used in a wide range of applications. f For civilian mobile communication systems operating in the low-frequency band (<4GHz), the trend towards miniaturization of electronic components necessitates ceramic dielectric materials with the highest possible dielectric constant.

[0003] In existing microwave ceramic capacitors, most use palladium / silver noble metals as internal electrodes and are sintered in an air atmosphere, resulting in high production costs. Using nickel as the internal electrode can effectively reduce material costs. However, nickel electrodes require sintering in a reducing atmosphere. Existing microwave ceramic materials undergo a reduction reaction during sintering, leading to semiconductorization of the ceramic dielectric and deterioration of insulation properties, rendering them unusable. Therefore, exploring and developing reduction-resistant microwave ceramic dielectric materials will greatly promote the development of microwave ceramic capacitors. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a reduction-resistant microwave temperature-stable ceramic capacitor, the ceramic dielectric material used therein, and its preparation method.

[0005] The present invention adopts the following technical solution: A ceramic dielectric material for a reduction-resistant microwave temperature-stabilized ceramic capacitor, comprising 100 molar parts of Ba x Sr 1- x Mo 1-y W yUsing O4 as the base material, the following molar amounts of components are added: 4-8 parts of CaRe4(MoO4)6, 2-5 parts of BiYMoO6, 0.5-1.0 parts of MgAl2O4, 0.2-0.8 parts of ZrSiO4, and 1-3 parts of Na2B2O7, wherein 0 < x < 0.15, 0 < y < 0.10, and Re = La, Nd, Ce.

[0006] Furthermore, the Ba x Sr 1-x Mo 1-y W y O4, CaRe4(MoO4)6, and BiYMoO6 were synthesized using a solid-state method.

[0007] A method for preparing a ceramic dielectric material for a reduction-resistant microwave temperature-stabilized ceramic capacitor includes the following steps: Step 1: Preparation of Ba by solid-state method x Sr 1-x Mo 1-y W y O4; Step 2: Preparation of CaRe4(MoO4)6 by solid-state method; Step 3: Preparation of BiYMoO6 by solid-state method; Step four, the Ba prepared in steps one through three... x Sr 1-x Mo 1-y W y O4, CaRe4(MoO4)6, BiYMoO6 are mixed with MgAl2O4, ZrSiO4, and Na2B2O7, deionized water and zirconium oxide beads are added, and the mixture is ball-milled for 4-6 hours, then dried and crushed to obtain the ceramic dielectric material for the reduction-resistant microwave temperature-stable ceramic capacitor.

[0008] Further, in step one, Ba is prepared by solid-state method. x Sr 1-x Mo 1-y W y The specific steps for operating O4 are as follows: Press Ba x Sr 1-x Mo 1- y W y The chemical composition of O4 is as follows: BaCO3, SrCO3, MoO3, and WO3 are weighed separately, and deionized water and zirconium oxide beads are added. The mixture is ball-milled for 5-8 hours, dried, and then sieved through a 40-80 mesh sieve. The powder is then calcined at 1100-1250℃ for 2-3 hours and naturally cooled to room temperature to obtain Ba. x Sr 1-x Mo 1-y W y O4.

[0009] Further, in step two, the specific operation for preparing CaRe4(MoO4)6 by solid-state method is as follows: Weigh CaCO3, Re2O3, and MoO3 according to the chemical formula of CaRe4(MoO4)6, add deionized water and zirconium oxide beads, mix and ball mill for 4-8 hours, dry the powder, sieve it through a 40-80 mesh sieve, calcine it at 800-900℃ for 2-3 hours, and cool it naturally to room temperature to obtain CaRe4(MoO4)6.

[0010] Furthermore, the specific operation for preparing BiYMoO6 by solid-state method is as follows: weigh Bi2O3, Y2O3, and MoO3 according to the chemical formula of BiYMoO6, add deionized water and zirconium oxide beads, mix and ball mill for 2-3 hours, dry the powder, sieve it through a 40-80 mesh sieve, calcine it at 700-750℃ for 1-2 hours, and cool it naturally to room temperature to obtain BiYMoO6.

[0011] A reduction-resistant microwave temperature-stabilized ceramic capacitor is prepared using the ceramic dielectric material described above.

[0012] Furthermore, the dielectric material is subjected to an MLCC process, with nickel as the internal electrode, and sintered in a N2 / H2 reducing atmosphere at a temperature of 1160-1250℃ for 2-5 hours to obtain the microwave temperature-stable ceramic capacitor.

[0013] As can be seen from the above description of the present invention, compared with the prior art, the beneficial effects of the present invention are: First, the microwave temperature-stable ceramic dielectric material with anti-reduction properties proposed in this invention is prepared by doping Sr and W in the A / B layers of the substrate BaMoO4 to improve its microwave characteristics. Then, BiYMoO6 and CaRe4(MoO4)6 synthesized by solid-state method are added, and MgAl2O4 and ZrSiO4 are doped to improve its anti-reduction performance during sintering. Finally, the sintering densification temperature of the material system is reduced under the action of Na2B2O7. The microwave dielectric ceramic prepared by this method has a sintering densification temperature in the range of 1150-1250℃, which can be adapted to the fabrication of microwave ceramic capacitors with high Q value using nickel as the internal electrode. Second, the miniaturization of microwave devices requires ceramic dielectric materials to have the highest possible dielectric constant. Introducing Bi into the molybdate system can effectively improve its dielectric constant. However, Bi has a large effect on improving the dielectric constant, so Y element needs to be doped. When the Bi content increases, the improvement of the dielectric constant of the material system becomes relatively gradual. Third, as a ceramic dielectric material used in microwave ceramic capacitors, it should have low dielectric loss tanδ and low temperature coefficient of resonant frequency τ. fBy introducing rare earth elements into the dielectric material in the form of CaRe4(MoO4)6, a higher quality factor can be obtained. This effectively reduces the tanδ and τ of the system while maintaining a high K value. f ; Fourth, the addition of MgAl2O4 and ZrSiO4, which have highly symmetrical structures, to the ceramic dielectric material effectively improves the redox potential of the system, thereby avoiding reduction reactions of each component and enabling nickel to be used as the internal electrode. Fifth, the sintering densification temperature of nickel electrodes is above 1150℃, so barium molybdate with a high melting point among molybdates needs to be selected as the base material. However, the melting point of barium molybdate is 1480℃, so borax sintering aid needs to be added to lower the sintering temperature to match the sintering temperature of nickel electrodes. Detailed Implementation

[0014] The present invention will be further described below through specific embodiments.

[0015] A microwave temperature-stabilized ceramic capacitor resistant to reduction is prepared using ceramic dielectric material. The preparation method specifically includes the following steps: the dielectric material is subjected to an MLCC process, with nickel as the internal electrode, and sintered in a N2 / H2 reducing atmosphere at a temperature of 1160-1250℃ for 2-5 hours to obtain the microwave temperature-stabilized ceramic capacitor.

[0016] Ceramic dielectric material, with 100 moles of Ba x Sr 1-x Mo 1-y W y Using O4 as the base material, the following molar amounts of components are added: 4-8 parts of CaRe4(MoO4)6, 2-5 parts of BiYMoO6, 0.5-1.0 parts of MgAl2O4, 0.2-0.8 parts of ZrSiO4, and 1-3 parts of Na2B2O7, where 0 < x < 0.15, 0 < y < 0.10, and Re = La, Nd, Ce; specifically Ba x Sr 1-x Mo 1-y W y O4 was synthesized from BaCO3, SrCO3, MoO3, and WO3 using a solid-state method; CaRe4(MoO4)6 was synthesized from CaCO3, Re2O3, and MoO3 using a solid-state method; and BiYMoO6 was synthesized from Bi2O3, Y2O3, and MoO3 using a solid-state method.

[0017] The preparation method of ceramic dielectric materials includes the following steps: Step 1: Preparation of Ba by solid-state method x Sr 1-x Mo 1-y W y O4: Press Bax Sr 1-x Mo 1-y W y The chemical composition of O4 is as follows: BaCO3, SrCO3, MoO3, and WO3 are weighed separately, and deionized water and zirconium oxide beads are added. The mixture is ball-milled for 5-8 hours, dried, and then sieved through a 40-80 mesh sieve. The powder is then calcined at 1100-1250℃ for 2-3 hours and naturally cooled to room temperature to obtain Ba. x Sr 1-x Mo 1-y W y O4; Step 2, solid-state method for preparing CaRe4(MoO4)6: Weigh CaCO3, Re2O3, and MoO3 according to the chemical formula of CaRe4(MoO4)6, add deionized water and zirconium oxide beads, mix and ball mill for 4-8 hours, dry the powder and sieve it through a 40-80 mesh sieve, calcine it at 800-900℃ for 2-3 hours, and cool it naturally to room temperature to obtain CaRe4(MoO4)6; Step 3, solid-state method for preparing BiYMoO6: Weigh Bi2O3, Y2O3, and MoO3 according to the chemical formula of BiYMoO6, add deionized water and zirconium oxide beads, mix and ball mill for 2-3 hours, dry the powder and sieve it through a 40-80 mesh sieve, calcine it at 700-750℃ for 1-2 hours, and cool it naturally to room temperature to obtain BiYMoO6; Step four, the Ba prepared in steps one through three... x Sr 1-x Mo 1-y W y O4, CaRe4(MoO4)6, BiYMoO6 are mixed with MgAl2O4, ZrSiO4, and Na2B2O7, deionized water and zirconium oxide beads are added, and the mixture is ball-milled for 4-6 hours, then dried and crushed to obtain the ceramic dielectric material for the reduction-resistant microwave temperature-stable ceramic capacitor. Example

[0018] A microwave temperature-stabilized ceramic capacitor resistant to reduction is prepared using ceramic dielectric material. The preparation method specifically includes the following steps: the dielectric material is subjected to an MLCC process, with nickel as the internal electrode, and sintered in a N2 / H2 reducing atmosphere at a temperature of 1120℃ for 3 hours to obtain the microwave temperature-stabilized ceramic capacitor.

[0019] Ceramic dielectric material, with 100 moles of Ba 0.92 Sr 0.08 Mo 0.95 W 0.05Using O4 as the base material, the following components are added in molar amounts: 7 parts CaLa4(MoO4)6, 2.8 parts BiYMoO6, 0.8 parts MgAl2O4, 0.6 parts ZrSiO4, and 3 parts Na2B2O7.

[0020] The preparation method of ceramic dielectric materials includes the following steps: Step 1: Preparation of Ba by solid-state method 0.92 Sr 0.08 Mo 0.95 W 0.05 O4: Press Ba 0.92 Sr 0.08 Mo 0.95 W 0.05 The chemical composition of O4 is as follows: BaCO3, SrCO3, MoO3, and WO3 were weighed separately, and then mixed with deionized water and zirconium oxide beads. The mixture was ball-milled for 7 hours, dried, and then sieved through an 80-mesh sieve. The powder was then calcined at 1230℃ for 2 hours and allowed to cool naturally to room temperature to obtain Ba2O3. 0.92 Sr 0.08 Mo 0.95 W 0.05 O4; Step 2, solid-state method for preparing CaRe4(MoO4)6: Weigh CaCO3, La2O3, and MoO3 according to the chemical formula of CaLa4(MoO4)6, add deionized water and zirconium oxide beads, mix and ball mill for 5 hours, dry the powder and sieve it through an 80-mesh sieve, calcine it at 900℃ for 2 hours, and cool it naturally to room temperature to obtain CaLa4(MoO4)6; Step 3, solid-state method for preparing BiYMoO6: Weigh Bi2O3, Y2O3, and MoO3 according to the chemical formula of BiYMoO6, add deionized water and zirconium oxide beads, mix and ball mill for 3 hours, dry the powder, sieve it through an 80-mesh sieve, calcine it at 700℃ for 1 hour, and cool it naturally to room temperature to obtain BiYMoO6. Step four, the Ba prepared in steps one through three... 0.92 Sr 0.08 Mo 0.95 W 0.05 O4, CaLa4(MoO4)6, BiYMoO6, MgAl2O4, ZrSiO4, and Na2B2O7 are mixed, deionized water and zirconium oxide beads are added, and the mixture is ball-milled for 4-6 hours, then dried and crushed to obtain the reduction-resistant microwave temperature-stable ceramic capacitor and its ceramic dielectric material.

[0021] Examples 2-6 have the same raw material composition and preparation process as Example 1, except that the proportions of each raw material are different. For details, please refer to Table 1. Example

[0022] A microwave temperature-stabilized ceramic capacitor resistant to reduction is prepared using ceramic dielectric material. The preparation method specifically includes the following steps: the dielectric material is subjected to an MLCC process, with nickel as the internal electrode, and sintered in a N2 / H2 reducing atmosphere at a temperature of 1120℃ for 3 hours to obtain the microwave temperature-stabilized ceramic capacitor.

[0023] Ceramic dielectric material, with 100 moles of Ba 0.92 Sr 0.08 Mo 0.95 W 0.05 Using O4 as the base material, the following components are added in molar amounts: 7 parts CaNd4(MoO4)6, 2.8 parts BiYMoO6, 0.8 parts MgAl2O4, 0.6 parts ZrSiO4, and 3 parts Na2B2O7.

[0024] The preparation method of ceramic dielectric materials includes the following steps: Step 1: Preparation of Ba by solid-state method 0.92 Sr 0.08 Mo 0.95 W 0.05 O4: Press Ba 0.92 Sr 0.08 Mo 0.95 W 0.05 The chemical composition of O4 is as follows: BaCO3, SrCO3, MoO3, and WO3 were weighed separately, and then mixed with deionized water and zirconium oxide beads. The mixture was ball-milled for 7 hours, dried, and then sieved through an 80-mesh sieve. The powder was then calcined at 1230℃ for 2 hours and allowed to cool naturally to room temperature to obtain Ba2O3. 0.92 Sr 0.08 Mo 0.95 W 0.05 O4; Step 2, solid-state preparation of CaNd4(MoO4)6: Weigh CaCO3, Nd2O3, and MoO3 according to the chemical formula of CaNd4(MoO4)6, add deionized water and zirconium oxide beads, mix and ball mill for 5 hours, dry the powder and sieve it through an 80-mesh sieve, calcine it at 900℃ for 2 hours, and cool it naturally to room temperature to obtain CaNd4(MoO4)6; Step 3, solid-state preparation of BiYMoO6: Weigh Bi2O3, Y2O3, and MoO3 according to the chemical formula of BiYMoO6, add deionized water and zirconium oxide beads, mix and ball-mill for 3 hours. After drying, the powder is sieved through an 80-mesh sieve and calcined at 700℃ for 1 hour. After naturally cooling to room temperature, BiYMoO6 is obtained. Step four, the Ba prepared in steps one through three... 0.92 Sr 0.08 Mo 0.95 W0.05 O4, CaNd4(MoO4)6, BiYMoO6, MgAl2O4, ZrSiO4, and Na2B2O7 are mixed, deionized water and zirconium oxide beads are added, and the mixture is ball-milled for 4-6 hours, then dried and crushed to obtain the reduction-resistant microwave temperature-stable ceramic capacitor and its ceramic dielectric material. Example

[0025] A microwave temperature-stabilized ceramic capacitor resistant to reduction is prepared using ceramic dielectric material. The preparation process includes the following steps: using nickel as the internal electrode, sintering in a N2 / H2 reducing atmosphere at a temperature of 1220℃ for 3 hours to obtain the microwave temperature-stabilized ceramic capacitor.

[0026] Ceramic dielectric material, with 100 moles of Ba 0.92 Sr 0.08 Mo 0.95 W 0.05 Using O4 as the base material, the following molar amounts of the following components are added: 7 parts CaCe4(MoO4)6, 2.8 parts BiYMoO6, 0.8 parts MgAl2O4, 0.6 parts ZrSiO4, and 3 parts Na2B2O7.

[0027] The preparation method of ceramic dielectric materials includes the following steps: Step 1: Preparation of Ba by solid-state method 0.92 Sr 0.08 Mo 0.95 W 0.05 O4: Press Ba 0.92 Sr 0.08 Mo 0.95 W 0.05 The chemical composition of O4 is as follows: BaCO3, SrCO3, MoO3, and WO3 were weighed separately, and then mixed with deionized water and zirconium oxide beads. The mixture was ball-milled for 7 hours, dried, and then sieved through an 80-mesh sieve. The powder was then calcined at 1230℃ for 2 hours and allowed to cool naturally to room temperature to obtain Ba2O3. 0.92 Sr 0.08 Mo 0.95 W 0.05 O4; Step 2, solid-state method for preparing CaCe4(MoO4)6: Weigh CaCO3, Ce2O3, and MoO3 according to the chemical formula of CaCe4(MoO4)6, add deionized water and zirconium oxide beads, mix and ball mill for 5 hours, dry the powder and sieve it through an 80-mesh sieve, calcine it at 900℃ for 2 hours, and cool it naturally to room temperature to obtain CaCe4(MoO4)6; Step 3, solid-state preparation of BiYMoO6: Weigh Bi2O3, Y2O3, and MoO3 according to the chemical formula of BiYMoO6, add deionized water and zirconium oxide beads, mix and ball-mill for 3 hours. After drying, the powder is sieved through an 80-mesh sieve and calcined at 700℃ for 1 hour. After naturally cooling to room temperature, BiYMoO6 is obtained. Step four, the Ba prepared in steps one through three... 0.92 Sr 0.08 Mo 0.95 W 0.05 O4, CaCe4(MoO4)6, BiYMoO6, MgAl2O4, ZrSiO4, and Na2B2O7 are mixed, deionized water and zirconium oxide beads are added, and the mixture is ball-milled for 4-6 hours, then dried and crushed to obtain the reduction-resistant microwave temperature-stable ceramic capacitor and its ceramic dielectric material.

[0028] Comparative Examples 1-5 have the same raw material composition and preparation process as Example 1, except that the proportions of each raw material are different. For details, please refer to Table 1.

[0029] Comparative Example 6 A microwave temperature-stabilized ceramic capacitor resistant to reduction is prepared using ceramic dielectric material. The preparation process includes the following steps: using nickel as the internal electrode, sintering in a N2 / H2 reducing atmosphere at a temperature of 1220℃ for 3 hours to obtain the microwave temperature-stabilized ceramic capacitor.

[0030] Ceramic dielectric material, with 100 moles of Ba 0.92 Sr 0.08 Mo 0.95 W 0.05 Using O4 as the base material, the following components are added in molar amounts: 7 parts BaLa4(MoO4)6, 2.8 parts BiYMoO6, 0.8 parts MgAl2O4, 0.6 parts ZrSiO4, and 3 parts Na2B2O7.

[0031] The preparation method of ceramic dielectric materials includes the following steps: Step 1: Preparation of Ba by solid-state method 0.92 Sr 0.08 Mo 0.95 W 0.05 O4: Press Ba 0.92 Sr 0.08 Mo 0.95 W 0.05 The chemical composition of O4 is as follows: BaCO3, SrCO3, MoO3, and WO3 were weighed separately, and then mixed with deionized water and zirconium oxide beads. The mixture was ball-milled for 7 hours, dried, and then sieved through an 80-mesh sieve. The powder was then calcined at 1230℃ for 2 hours and allowed to cool naturally to room temperature to obtain Ba2O3. 0.92 Sr0.08 Mo 0.95 W 0.05 O4; Step 2, solid-state method for preparing BaLa4(MoO4)6: Weigh BaCO3, La2O3, and MoO3 according to the chemical formula of BaLa4(MoO4)6, add deionized water and zirconium oxide beads, mix and ball mill for 5 hours, dry the powder and sieve it through an 80-mesh sieve, calcine it at 900℃ for 2 hours, and cool it naturally to room temperature to obtain BaLa4(MoO4)6; Step 3, solid-state preparation of BiYMoO6: Weigh Bi2O3, Y2O3, and MoO3 according to the chemical formula of BiYMoO6, add deionized water and zirconium oxide beads, mix and ball-mill for 3 hours. After drying, the powder is sieved through an 80-mesh sieve and calcined at 700℃ for 1 hour. After naturally cooling to room temperature, BiYMoO6 is obtained. Step four, the Ba prepared in steps one through three... 0.92 Sr 0.08 Mo 0.95 W 0.05 O4, BaLa4(MoO4)6, BiYMoO6, MgAl2O4, ZrSiO4, and Na2B2O7 are mixed, deionized water and zirconium oxide beads are added, and the mixture is ball-milled for 4-6 hours, then dried and crushed to obtain the reduction-resistant microwave temperature-stable ceramic capacitor and its ceramic dielectric material.

[0032] Comparative Example 7 A microwave temperature-stabilized ceramic capacitor resistant to reduction is prepared using ceramic dielectric material. The preparation process includes the following steps: using nickel as the internal electrode, sintering in a N2 / H2 reducing atmosphere at a temperature of 1220℃ for 3 hours to obtain the microwave temperature-stabilized ceramic capacitor.

[0033] Ceramic dielectric material, with 100 moles of Ba 0.92 Sr 0.08 Mo 0.95 W 0.05 Using O4 as the base material, the following components are added in molar amounts: 7 parts CaLa4(MoO4)6, 2.8 parts Bi2MoO6, 0.8 parts MgAl2O4, 0.6 parts ZrSiO4, and 3 parts Na2B2O7.

[0034] The preparation method of ceramic dielectric materials includes the following steps: Step 1: Preparation of Ba by solid-state method 0.92 Sr 0.08 Mo 0.95 W 0.05 O4: Press Ba 0.92 Sr 0.08 Mo 0.95 W0.05 The chemical composition of O4 is as follows: BaCO3, SrCO3, MoO3, and WO3 were weighed separately, and then mixed with deionized water and zirconium oxide beads. The mixture was ball-milled for 7 hours, dried, and then sieved through an 80-mesh sieve. The powder was then calcined at 1230℃ for 2 hours and allowed to cool naturally to room temperature to obtain Ba2O3. 0.92 Sr 0.08 Mo 0.95 W 0.05 O4; Step 2, solid-state method for preparing CaLa4(MoO4)6: Weigh CaCO3, La2O3, and MoO3 according to the chemical formula of CaLa4(MoO4)6, add deionized water and zirconium oxide beads, mix and ball mill for 5 hours, dry the powder, sieve it through an 80-mesh sieve, calcine it at 900℃ for 2 hours, and cool it naturally to room temperature to obtain CaLa4(MoO4)6; Step 3, solid-state preparation of Bi2MoO6: Weigh Bi2O3 and MoO3 according to the chemical formula of Bi2MoO6, add deionized water and zirconium oxide beads, mix and ball mill for 3 hours, dry the powder, sieve through an 80-mesh sieve, calcine at 700℃ for 1 hour, and naturally cool to room temperature to obtain Bi2MoO6. Step four, the Ba prepared in steps one through three... 0.92 Sr 0.08 Mo 0.95 W 0.05 O4, CaLa4(MoO4)6, Bi2MoO6, MgAl2O4, ZrSiO4, and Na2B2O7 are mixed, deionized water and zirconium oxide beads are added, and the mixture is ball-milled for 4-6 hours, then dried and crushed to obtain the reduction-resistant microwave temperature-stable ceramic capacitor and its ceramic dielectric material.

[0035] Comparative Example 8 A microwave temperature-stabilized ceramic capacitor resistant to reduction is prepared using ceramic dielectric material. The preparation process includes the following steps: using nickel as the internal electrode, sintering in a N2 / H2 reducing atmosphere at a temperature of 1220℃ for 3 hours to obtain the microwave temperature-stabilized ceramic capacitor.

[0036] Ceramic dielectric material, with 100 moles of Ba 0.92 Sr 0.08 Mo 0.95 W 0.05 Using O4 as the base material, the following components are added in molar amounts: 7 parts CaLa4(MoO4)6, 2.8 parts Y2MoO6, 0.8 parts MgAl2O4, 0.6 parts ZrSiO4, and 3 parts Na2B2O7.

[0037] The preparation method of ceramic dielectric materials includes the following steps: Step 1: Preparation of Ba by solid-state method 0.92 Sr 0.08 Mo 0.95 W 0.05 O4: Press Ba 0.92 Sr 0.08 Mo 0.95 W 0.05 The chemical composition of O4 is as follows: BaCO3, SrCO3, MoO3, and WO3 were weighed separately, and then mixed with deionized water and zirconium oxide beads. The mixture was ball-milled for 7 hours, dried, and then sieved through an 80-mesh sieve. The powder was then calcined at 1230℃ for 2 hours and allowed to cool naturally to room temperature to obtain Ba2O3. 0.92 Sr 0.08 Mo 0.95 W 0.05 O4; Step 2, solid-state method for preparing CaLa4(MoO4)6: Weigh CaCO3, La2O3, and MoO3 according to the chemical formula of CaLa4(MoO4)6, add deionized water and zirconium oxide beads, mix and ball mill for 5 hours, dry the powder, sieve it through an 80-mesh sieve, calcine it at 900℃ for 2 hours, and cool it naturally to room temperature to obtain CaLa4(MoO4)6; Step 3, solid-state preparation of Y2MoO6: Weigh Y2O3 and MoO3 according to the chemical formula Y2MoO6, add deionized water and zirconium oxide beads, mix and ball mill for 3 hours, dry the powder, sieve through an 80-mesh sieve, calcine at 700℃ for 1 hour, and naturally cool to room temperature to obtain Y2MoO6. Step four, the Ba prepared in steps one through three... 0.92 Sr 0.08 Mo 0.95 W 0.05 O4, CaLa4(MoO4)6, Y2MoO6, MgAl2O4, ZrSiO4, and Na2B2O7 are mixed, deionized water and zirconium oxide beads are added, and the mixture is ball-milled for 4-6 hours, then dried and crushed to obtain the reduction-resistant microwave temperature-stable ceramic capacitor and its ceramic dielectric material.

[0038] Table 1. Composition of each example (mol%)

[0039] The ceramic capacitors prepared in Examples 1-8 and Comparative Examples 1-8 were tested and the following data were obtained, as shown in Table 2 below.

[0040] Table 2 Performance Test Table

[0041] in, e r Dielectric constant; tf Temperature coefficient of resonant frequency; BDV Breakdown voltage; IR Insulation resistance; tanδ : Loss tangent value.

[0042] As shown in the table above, Examples 1-8 of this application investigate the effect of component content on the electrical properties of pulse power ceramic dielectric materials by fine-tuning the content of each component; among them, the microwave-stabilized ceramic capacitor prepared in Example 1 has the best overall electrical performance: a higher dielectric constant ( K = 82), lower loss tangent ( tanδ =0.5), and the temperature coefficient of the resonant frequency close to zero bias (-20.2~-25.6). ppm / K The highest breakdown electric field (>9.2) is observed at high dielectric constants. KV / m m ).

[0043] A comparison of Example 1 with Comparative Examples 1-5 shows that the additives of each component in the product... e r , t f , BDV , IR , tanδ The dielectric materials play an important role in the electrical properties. In Comparative Examples 3 and 4, after losing MgAl2O4 and ZrSiO4 respectively, the dielectric materials sintered in a reducing atmosphere. The reduction resistance was insufficient, which led to the semiconductorization of the dielectric materials and ultimately the deterioration of electrical properties.

[0044] By comparing Example 1 and Comparative Example 6, it can be seen that after replacing the low-melting-point barium molybdate with the high-melting-point barium molybdate, the dielectric constant of the dielectric material decreases slightly and the temperature coefficient increases. This indicates that excessive barium molybdate will increase the densification firing temperature of the dielectric material.

[0045] A comparison of Example 1 and Comparative Examples 7-8 shows that Bi and Y elements require synergistic effects to increase the K value and reduce the temperature coefficient. With only Bi, the dielectric constant increases significantly, but the temperature coefficient deteriorates. With only Y, although the temperature coefficient can be further reduced, the energy storage density of the dielectric material is low, which is not conducive to the miniaturization of devices.

[0046] In summary, the dielectric material for the reduction-resistant microwave temperature-stable ceramic capacitor proposed in this invention uses BaMoO4 as the substrate, and doesps Sr and W at the A / B sites to improve its microwave characteristics. Then, BiYMoO6 and CaRe4(MoO4)6 synthesized by solid-state method are added, and its reduction resistance during sintering is improved by doping with MgAl2O4 and ZrSiO4. Finally, the sintering densification temperature of the material system is reduced under the action of Na2B2O7. The microwave dielectric ceramic prepared by this method has a sintering densification temperature in the range of 1150~1250℃, which is suitable for use as a microwave ceramic capacitor with high K, high Q value and zero bias resonant temperature coefficient with nickel as the internal electrode.

[0047] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the specification should still fall within the scope of the present invention.

Claims

1. A ceramic dielectric material for a reduction-resistant microwave temperature-stabilized ceramic capacitor, characterized in that: With 100 moles of Ba x Sr 1-x Mo 1-y W y Using O4 as the base material, the following molar amounts of components are added: 4-8 parts of CaRe4(MoO4)6, 2-5 parts of BiYMoO6, 0.5-1.0 parts of MgAl2O4, 0.2-0.8 parts of ZrSiO4, and 1-3 parts of Na2B2O7, wherein 0 < x < 0.15, 0 < y < 0.10, and Re = La, Nd, Ce.

2. The ceramic dielectric material for a reduction-resistant microwave temperature-stabilized ceramic capacitor according to claim 1, characterized in that: The Ba x Sr 1-x Mo 1-y W y O4, CaRe4(MoO4)6, and BiYMoO6 were synthesized using a solid-state method.

3. The method for preparing a ceramic dielectric material for a reduction-resistant microwave temperature-stabilized ceramic capacitor according to claim 1, characterized in that: Includes the following steps: Step 1: Preparation of Ba by solid-state method x Sr 1-x Mo 1-y W y O4; Step 2: Preparation of CaRe4(MoO4)6 by solid-state method; Step 3: Preparation of BiYMoO6 by solid-state method; Step four, the Ba prepared in steps one through three... x Sr 1-x Mo 1-y W y O4, CaRe4(MoO4)6, BiYMoO6 are mixed with MgAl2O4, ZrSiO4, and Na2B2O7, deionized water and zirconium oxide beads are added, and the mixture is ball-milled for 4-6 hours, then dried and crushed to obtain the ceramic dielectric material for the reduction-resistant microwave temperature-stable ceramic capacitor.

4. The method for preparing a ceramic dielectric material for a reduction-resistant microwave temperature-stabilized ceramic capacitor according to claim 3, characterized in that: Step 1: Preparation of Ba by solid-state method x Sr 1-x Mo 1-y W y The specific steps for operating O4 are as follows: Press Ba x Sr 1-x Mo 1- y W y The chemical composition of O4 is as follows: BaCO3, SrCO3, MoO3, and WO3 are weighed separately, and deionized water and zirconium oxide beads are added. The mixture is ball-milled for 5-8 hours, dried, and then sieved through a 40-80 mesh sieve. The powder is then calcined at 1100-1250℃ for 2-3 hours and naturally cooled to room temperature to obtain Ba. x Sr 1-x Mo 1-y W y O4.

5. The method for preparing a ceramic dielectric material for a reduction-resistant microwave temperature-stabilized ceramic capacitor according to claim 3, characterized in that: Step two, the specific operation for preparing CaRe4(MoO4)6 by solid-state method is as follows: Weigh CaCO3, Re2O3, and MoO3 according to the chemical formula of CaRe4(MoO4)6, add deionized water and zirconium oxide beads, mix and ball mill for 4-8 hours, dry the powder and sieve it through a 40-80 mesh sieve, calcine it at 800-900℃ for 2-3 hours, and cool it naturally to room temperature to obtain CaRe4(MoO4)6.

6. The method for preparing a ceramic dielectric material for a reduction-resistant microwave temperature-stabilized ceramic capacitor according to claim 3, characterized in that: The specific steps for preparing BiYMoO6 by solid-state method are as follows: Weigh Bi2O3, Y2O3, and MoO3 according to the chemical formula of BiYMoO6, add deionized water and zirconium oxide beads, mix and ball mill for 2-3 hours, dry the powder, sieve it through a 40-80 mesh sieve, calcine it at 700-750℃ for 1-2 hours, and cool it naturally to room temperature to obtain BiYMoO6.

7. A microwave temperature-stabilized ceramic capacitor resistant to reduction, characterized in that: It is prepared using the ceramic dielectric material described in claim 1.

8. The method for preparing a reduction-resistant microwave temperature-stabilized ceramic capacitor according to claim 7, characterized in that: Includes the following steps: The dielectric material is subjected to an MLCC process, with nickel as the internal electrode, and sintered in a N2 / H2 reducing atmosphere at a temperature of 1160-1250℃ for 2-5 hours to obtain the microwave temperature-stable ceramic capacitor.

Images