33results about How to "High Qf value" patented technology

A glass ceramic composition is provided which can be fired at a temperature of 1,000° C. or less to form a sintered body having a low relative dielectric constant, a small temperature coefficient of resonant frequency, a small change in capacitance before and after a loading test, a high Qf value, high electrical insulating reliability, and a high flexural strength. A glass ceramic composition forming glass ceramic layers laminated to each other in a multilayer ceramic substrate is also provided. The glass ceramic composition includes a first ceramic powder containing forsterite as a primary component; a second ceramic powder containing SrTiO₃ and/or TiO₂ as a primary component; a third ceramic powder containing BaZrO₃ as a primary component; a fourth ceramic powder containing SrZrO₃ as a primary component; and a borosilicate glass which contains Li₂O, MgO, B₂O₃, SiO₂, and ZnO, and also which contains at least one of CaO, BaO, and SrO.

An insulating ceramic composition forming insulating ceramic layers (3) stacked in a multilayer ceramic substrate (2) used in a monolithic ceramic electronic component, such as a multilayer ceramic module (1). The insulating ceramic composition contains a first ceramic powder mainly containing forsterite, a second ceramic powder mainly containing at least one compound selected from the group consisting of CaTiO₃, SrTiO₃, and TiO₂, and a borosilicate glass powder. The borosilicate glass powder contains 3 to 15 percent by weight of lithium in terms of Li₂O, 30 to 50 percent by weight of magnesium in terms of MgO, 15 to 30 percent by weight of boron in terms of B₂O₃, 10 to 35 percent by weight of silicon in terms of SiO₂, 6 to 20 percent by weight of zinc in terms of ZnO, and 0 to 15 percent by weight of aluminum in terms of Al₂O₃. The insulating ceramic composition can be fired at a temperature of 1000° C. or less, and the resulting sintered compact has a low relative dielectric constant, a resonance frequency with a low temperature coefficient, and a high Q value.

The invention discloses a Li2MoO4-Mg2SiO4-based composite ceramic microwave material and a preparation method thereof. A chemical general formula of the composite ceramic can be written as xLi2MoO4-(1-x)Mg2SiO4, wherein x=10 wt%, 50 wt%, 70 wt%, 80 wt%, 85 wt%, 90 wt% or 95 wt%. The method comprises the following steps: firstly weighing magnesium oxide and silicon dioxide according to a certain stoichiometric ratio, performing ball milling for uniformization, performing drying, and performing pre-sintering to obtain Mg2SiO4; and weighing the prepared Mg2SiO4 and a Li2MoO4 raw material according to a certain weight ratio, adding 15 wt% of deionized water, performing uniform mixing, performing heat pressing on the mixture at 200 DEG C and 500 MPa for 60 min, and performing drying at 120 DEGC for 24 h to remove residual water to obtain the ultra-low-temperature cold sintered xLi2MoO4-(1-x)Mg2SiO4 composite ceramic material. Compared with traditional high-temperature solid-phase sintering(often higher than 1000 DEG C or more), the method provided by the invention has a sintering temperature in the range from room temperature to 200 DEG C; and the method provided by the invention hasa simple process, saves energy and can be widely applied to production of Li2MoO4-Mg2SiO4 composite ceramic substrates.

The invention discloses a microwave dielectric material with a near-zero temperature coefficient of resonance frequency. TiO2, ZnO, Nb2O5 and ZrO2 are adopted as the raw materials, the expression of atarget synthetic compound is (Zr1-xTix)1-y(Zn1/3Nb2/3)yO2, wherein x=0.6-0.7, and y=0.1-0.3. The preparation method includes: firstly proportioning the raw materials according to a stoichiometric equation, carrying out ball milling, drying and sieving, performing presintering at 1050DEG C, then carrying out ball milling and drying, conducting granulation, and then performing pressing into a greenbody; and heating the green body to 1250DEG C at a rate of 5DEG C/min, carrying out heat preservation for 30min, then performing cooling to 1150DEG C at a rate of 10DEG C/min, conducting heat preservation for 12h, and then performing cooling to obtain the microwave dielectric material with a near-zero temperature coefficient of resonance frequency. The invention adopts two-stage sintering, firstly the green body is heated to a high temperature and is subjected to heat preservation for a short period of time, and then heat preservation is carried out at a low temperature for a long time, so that the ceramic reaches high density, meanwhile, the residual stress between two phases is reduced, and the defect of low Qf value of a two-phase composite microwave dielectric ceramic material is effectively improved.

The present invention discloses a low-temperature co-fired microwave dielectric ceramic material very suitable for LTCC process production and a preparation method thereof. The low-temperature co-fired microwave dielectric ceramic material comprises 87-97wt% of Ba4 (Nd1.0-XBix) 9.33 (Ti0.9Zr0.1) 18O54, 0-6wt% of powder a and 3-7wt% of powder b, the powder a is a pre-calcined body, comprises Nd2O3 and Al2O3 in the molar ratio of 1:1, and has a chemical general formula of NdAlO3; and the powder b is a pre-calcined body, comprises BaO, CuO and B2O3 in the molar ratio of 1:1: 1, and has a chemical general formula of BaCu (B2O5). The low-temperature co-fired microwave dielectric ceramic material is free of glass melting and low in manufacturing cost, the sintering temperature is lower than 950 DEG C, the low-temperature co-fired microwave dielectric ceramic material can be matched with silver for co-firing, relative dielectric constant is 55-70, Qf value is 3000-5000GHz, and the resonance frequency temperature coefficient is adjustable.

The invention discloses rapidly-molded microwave dielectric ceramic and a preparation method thereof. A biological molecular material, a plasticizer and de-ionized water are mixed to obtain a crosslinking framework for gel casting; the biological molecular material and the plasticizer can form a hydrogen bond in a solution; the hydrogen bond is used as the plasticizer to improve the strength of agreen body; independently mixing ceramic powder and the residual de-ionized water, and a condition that the ceramic powder is directly mixed with the crosslinking framework for the gel casting to generate an adhering phenomenon is avoided, so that the ceramic powder can be sufficiently and uniformly mixed with the crosslinking framework; finally, ceramic is rapidly formed at certain temperature through adhering and sintering, the sample preparation time is greatly shortened and defects caused by the fact that organic matters are not adhered completely are avoided at the same time, so that themicrowave dielectric ceramic with good performance can be obtained; compared with a sample prepared by utilizing a traditional solid-phase method utilizing the same powder, a microwave dielectric ceramic sample prepared by the method has better performance; the dielectric loss is reduced by 26.01 percent, the Q-unloaded is improved by 35.6 percent and the QF (Quality Factor) value is improved by 76.85 percent.

The invention discloses a microwave ceramic filer element. The microwave ceramic filer element is composed of the following raw materials in percentage by weight: 5%-15% of Mg, 5%-15% of Sm, 5%-15% ofCa, 5%-15% of Zn, 5%-15% of Al, 5%-15% of Sr, 0.01%-0.1% of La, 0.01%-0.1% of Mn, 0.01%-0.1% of Sn, 0.01%-0.1% of Co, 0.01%-0.1% of Bi, 30%-40% of Ti, 0.01%-0.1% of Cu, 0.01%-0.1% of Ni, 0.01%-0.1% of Sn, 0.01%-0.1% of Pb, 0.1%-0.9% of Zr, 0.1%-0.9% of Nd, 0.1%-0.9% of Ta and 0.1%-0.9% of Ce. The raw materials are mixed according to a certain ratio, through working procedures of ball milling, drying, synthesizing, tabletting, firing and the like, energy consumption is greatly reduced, and a finished product with an ultrahigh Qf value can be obtained, has an outstanding electrical property, mechanical property and thermal property, especially has high mechanical strength, resistance to high and low temperature and high humidity, resistance to radiation, high dielectric strength and good aging performance, has the advantages of high stop-band suppression, low pass-band insertion loss, a wide frequency band, high power, a far spurious pass-band, in-band flat group delay and small size, is excellent in comprehensive performance, uniform in element and higher in reliability, and has important industrial application values.

The invention relates to a microwave dielectric material suitable for ultralow-temperature sintering and a preparation method thereof, the microwave dielectric material is a Bi2O3-B2O3 system, the molar ratio of Bi2O3 to B2O3 of the microwave dielectric material is x: y, x is greater than or equal to 1 and less than or equal to 12, and y is greater than or equal to 1 and less than 4. The preparation method comprises the following steps: (1) taking B2O3 and Bi2O3 as raw materials, mixing the B2O3 and the Bi2O3 according to a molar ratio of x: y, putting the powder into a ball milling tank, carrying out ball milling, and then pre-sintering to obtain pre-sintered ceramic powder; and (2) carrying out wet ball milling treatment on the pre-sintered ceramic powder obtained in the step (1), drying, adding an adhesive, granulating, tabletting, discharging the adhesive, and sintering to obtain the microwave dielectric material. The preparation process is simple, the preparation cost is low, thehigh-performance microwave dielectric material suitable for ultralow-temperature sintering is successfully developed by adopting an improved solid-phase reaction method, and the preparation method atultralow temperature provides convenience for integration of the substrate and a microwave circuit.

The invention provides microwave ceramic and a preparation method thereof. The microwave ceramic comprises the following components in parts by weight: 100 parts of silicate titanate complex and 0.1-0.4 part of a metal oxide, the silicate titanate complex is (CaMg < 1-x > Zn < x > Si<2>O<6>) < y >-(SrTiO<3>) < 1-y >; the metal oxide is Al2O3 and/or CaO; wherein 0 < = x < = 0.1, and 0.8 < = y < = 0.9. Compared with the traditional microwave ceramic, the microwave ceramic disclosed by the invention can obtain better microwave dielectric property and higher Qf value, so that the loss is lower, the temperature coefficient of resonance frequency can be adjusted as required, the preparation process is simple, and large-scale mass production can be realized.

The invention discloses a ceramic material. According to the invention, MgaSibCacTidO(a+2b+c+2d) is used as a basic formula, and Mg4NbTaO9-Al2O3 and the like are compositely doped, so that the obtained low-dielectric-constant microwave ceramic material has the following properties: the relative dielectric constant is 8-10, the Qf is 80000-100000, the temperature coefficient of resonance frequencyis 0+/-10ppm/DEG C, a wide sintering process window and good machinability are achieved. Meanwhile, the invention also discloses a preparation method of the ceramic material.

This application belongs to the technical field of microwave dielectric ceramics. The application provides a metal compound, a microwave dielectric ceramic and a preparation method thereof, and the microwave dielectric ceramic of the application includes a metal compound having the following general structure: (1-y)Ba ₃ Zn _x co _1‑x Nb ₂ o ₉ ‑yBa ₈ CoNb ₆ o ₂₄ , where, x=0~1, y=0~0.1, by introducing Ba ₈ CoNb ₆ o ₂₄ The new phase of non-stoichiometric ratio can be sintered in the liquid phase, which inhibits the volatilization of components, so that the prepared microwave dielectric ceramic has a stable B-site 1:2 long-range ordered structure and improves the Qf value. The microwave dielectric ceramic dielectric constant of this application is between 32.8 and 40.2, Q×f>56500GHz, up to 124300GHz, has the advantages of high Qf value and low dielectric loss, and the temperature coefficient of resonance frequency is -10.6PPM/℃~ Continuously adjustable between +28.3PPM/℃. The preparation method of the present application is simple, the manufacturing cost is low, meets the requirements of environmental protection, is non-toxic, and has no pollution to the environment; the sintering temperature is low, and the performance of the product can be guaranteed without long-term annealing, and the performance of the prepared product can be avoided due to volatilization of components. deterioration.

The invention discloses a cordierite microwave dielectric material with an ultralow dielectric constant and a near-zero temperature coefficient of resonance frequency, and belongs to the technical field of microwave electronic ceramic materials, the chemical composition of the material is Mg2-xLi2xAl4Si5O18, x is greater than 0 and less than or equal to 0.08, and the preparation method comprises the following steps: weighing MgO, Al2O3, Li2CO3 and SiO2 raw materials according to the stoichiometric ratio of the chemical formula; and then carrying out a series of processes such as ball milling, drying, calcining, secondary ball milling, drying, granulation forming, rubber discharging and sintering, and adopting a solid-phase reaction method. According to the difference of x, the material contains two phases, namely Mg2Al4Si5O18 and MgAl2O4, the material has an adjustable dielectric constant between 4.22 and 4.76 and a near-zero resonance temperature coefficient (-7.0 ppm/DEG C), so that the material has a wide application prospect in the fields of 5G communication, Internet of Things, millimeter wave communication and the like.

The invention provides a ceramic material with a high dielectric constant and a high Qf value and a preparation method thereof, and relates to the field of information function materials. The ceramicmaterial comprises a main crystalline phase and a modified additive. The main crystalline phase includes a main material and an auxiliary material. The general chemical formula of the main crystal phase is Ba4+2xLn4+8xTi22-7xO54. yZr0.8Sn0.2TiO4, wherein x is larger than 0 and smaller than 0.13, and y is larger than 0 and smaller than 0.05. Ba4+2xLn4+8xTi22-7xO54 is the chemical general formula ofthe main material, and Ln is selected from one or more of La, Y, Sm, Dy, Ho, Er and Nd. Zr0.8Sn0.2TiO4 is used as a chemical formula of an auxiliary material. The mass fraction of the main crystal phase in the ceramic material is 99-99.5 wt%, and the mass fraction of the modified additive in the ceramic material is 0.5-1wt%. The main material and the auxiliary material are respectively synthesized by adopting a solid-phase method to prepare a uniform powdery ceramic material, the powdery ceramic material is sintered to obtain the ceramic material with high dielectric constant and high Qf value, and the material can meet the requirements of microwave devices on high dielectric constant and high Qf value.