148results about How to "Resonant frequency temperature coefficient is small" patented technology

The invention discloses low-temperature sintered microwave dielectric ceramic and a sintering method thereof. The low-temperature sintered microwave dielectric ceramic comprises Li2MTi3O8 and N, wherein an M element is Zn, Ni, Co or Mg, and N is B2O3, V2O5, CuO or Bi2O3. The performance of a product prepared by adopting a microwave sintering method disclosed by the invention is superior to that of a traditional solid-phase sintered product, the high-frequency dielectric constant (epsilonr) of the product reaches 20 to 30, a Q*f value reaches up to 6000 to 59000GHz, and the temperature coefficient (tauf) of a resonance frequency is small. Moreover, the presintering time and the sintering time can be shortened, and the sintering temperature is decreased, so that the requirements of LTCC (Low Temperature Co-fired Ceramic) production can be met, the performance of the product is improved, energy sources are saved, the production cost is lowered, the low-temperature sintered microwave dielectric ceramic can be used for the manufacture of microwave devices, such as an LTCC system, a multilayer dielectric resonator, a microwave antenna, a filter and the like, the volatilization of low-melting-point substances is inhibited, the environment is protected, and the low-temperature sintered microwave dielectric ceramic has an important industrial application value.

The invention discloses a low-temperature sintering microwave dielectric ceramic Li2Ca2Si2O7 and a preparation method thereof. The chemical composition formula of the low-temperature sintering microwave dielectric ceramic is Li2Ca2Si2O7. The preparation method comprises the steps of (1) weighing and batching original powder of Li2CO3, CaCO3 and SiO2 with the purity being over 99.9% according to the chemical formula Li2Ca2Si2O7; (2) carrying out mixing and wet ball-milling on raw materials obtained in the step (1) for 12 hours, taking distilled water as a solvent, drying, and then, pre-sintering in an air atmosphere for 6 hours at the temperature of 800 DEG C; (3) adding a binder into powder prepared in the step (2), granulating, then, carrying out compression molding, and finally, sintering in the air atmosphere for 4 hours at the temperature of 870-900 DEG C, wherein a polyvinyl alcohol solution with the mass concentration of 5% is adopted as the binder, and the dosage of the binder accounts for 3% of the total mass of the powder. According to the ceramic prepared by the preparation method, the sintering at the temperature of 870-900 DEG C is good, the dielectric constant reaches 7-8, the quality factor (Qf) reaches up to 94,000-104,000GHz, and the temperature coefficient of resonance frequency is small, so that the ceramic has a great application value in industries.

The invention provides a microwave medium ceramic material with low dielectric constant, low deterioration and good thermal stability. The material is a solid solution medium ceramic with a formula of uZnO-vSiO2-wTiO2, wherein 58.0 mol%<=u<=69.0 mol%, 28.0 mol%<=v<=35.0 mol%, 3.0 mol%<=w<=7 mol%, the principal crystalline phase is Zn2SiO4, the secondary crystalline is TiO2.

The invention discloses a low temperature sintered microwave dielectric ceramic Li2W4O13 and a preparation method thereof. The chemical formula of the dielectric ceramic material is Li2W4O13. The preparation method comprises the following steps of: (1) proportioning original powder of Li2CO3 and WO3 with purity over 99.9% according to the composition of Li2W4O13; (2) mixing the raw material in step (1) by a wet ball mill for 12 hours by taking distilled water as a solvent, and drying and pre-sintering for 6 hours in atmosphere at 500 DEG C; and (3) adding an adhesive to the prepared powder obtained in step (2) and prilling, then pressing and forming, and finally, sintering for 4 hours in atmosphere at 540-560 DEG C, wherein the adhesive is a polyvinyl alcohol liquor with mass concentration of 5%, and accounts for 3% of the total weight of the powder. Ceramic prepared by the invention is well sintered at 540-560 DEG C, and the dielectric constant reaches 11-12, and the quality factor Qf value reaches 71000-75000GHz. The ceramic is less in temperature coefficient of resonance frequency and has an extremely large application value in industry.

The invention discloses a microwave dielectric ceramic material for a multi-layer ceramic capacitor and a preparing method of the microwave dielectric ceramic material, and belongs to the technical field of electronic ceramic. The ceramic material is prepared from calcium-doped (MgZn)TiO3 system ceramic and a composite burning improver through ball milling mixing, granulating, forming, glue discharging and sintering, wherein the main crystal phase of the calcium-doped (MgZn)TiO3 system ceramic is MgTiO3, and the composite burning improver is prepared from BaCO3, B2O3, SiO2 and one or more of Li2CO3, Nb2O5 and Nd2O3. The prepared ceramic material has the advantages that a medium dielectric constant is achieved, sintering can be carried out at the medium temperature, a high Qf value is achieved, and the frequency temperature coefficient is stable. The preparing process is environmentally friendly and free of pollution, and the ceramic material can be used at the microwave frequency band of 300 M-300 GHz, can be widely applied to filters, oscillators and other microwave devices, and is especially suitable for the multi-layer ceramic capacitor.

The invention discloses a low-temperature sintered tungstate microwave dielectric ceramic Li2MW2O8 and a preparation method thereof. The low-temperature sintered tungstate microwave dielectric ceramic is made of a material with the component of Li2MW2O8, wherein M is selected from one of Zn, Mg and Cu. The preparation method of the low-temperature sintered tungstate microwave dielectric ceramic Li2MW2O8 comprises the following steps of: (1) weighting and proportioning initial Li2CO3, MO and WO3 powders with the purities of over 99.9% according to the chemical formula Li2MW2O8, wherein M is selected from one of Zn, Mg and Cu; (2) performing wet-type ball milling and mixing on the raw materials for 12 hours, drying the raw materials, and then, presintering the raw materials at 600-DEG C atmosphere for 6 hours, wherein distilled water is used as a solvent; and (3) adding a binder into the prepared powder, pelleting, then, carrying out compression moulding, and finally, sintering at 650-700 DEG C atmosphere for 4 hours, wherein the binder is a 5wt% polyvinyl alcohol solution and accounts for 3% of the total quantity of the powder. The ceramic prepared by the invention is good in sintering at the temperature of 650-700 DEG C, high dielectric constant up to 22-24, high quality factor (Qf) value up to 67000-86000GHz and small temperature coefficient of resonance frequency.

The invention discloses a low temperature sintered microwave dielectric ceramic BiTiNbO6 and a preparation method thereof. The chemical formula of the low temperature sintered microwave dielectric ceramic is BiTiNbO6. The preparation method comprises the following steps: (1) weighing and mixing original powder, with purity above 99.9%, of Bi2O3, TiO2 and Nb2O5 according to the chemical formula BiTiNbO6; (2) carrying out wet ball milling on the raw material mixture obtained in the step (1) for 12 hours and presintering the powder in an atmosphere at 850 DEG C for 6 hours after drying the powder, wherein the solvent is distilled water; (3) adding a binder to the powder prepared in the step (2) and then granulating the mixture, then carrying out compression forming and finally sintering the product in an atmosphere at 910-940 DEG C for 4 hours, wherein a polyvinyl alcohol solution with mass concentration of 5% is adopted as the binder and the dosage of the binder is 3% of the total mass of the powder. The prepared ceramic is well sintered at 910-940 DEG C, has dielectric constant of 26-27 and quality factor (Qf) as high as 56000-71000GHz, has low temperature coefficient of resonance frequency, can be co-sintered with Ag electrodes at low temperature and has great application value in industry.

The invention discloses a low temperature sintered microwave dielectric ceramic Li2Ba1-xSrxTi4O16 and a preparation method thereof. The components of the ceramic are shown in the formula of Li2Ba1-xSrxTi4O16, wherein x is more than or equal to 0 and less than or equal to 1. The preparation method comprises the following steps of: preparing raw materials of BaCO3, SrCO3, Li2CO3 and TiO2 original powder with the purity of over 99.9 percent according to the formula of Li2Ba1-xSrxTi4O16, wherein x is more than or equal to 0 and less than or equal to 1; mixing the prepared raw materials for 12 hours through wet ball-milling, wherein a solvent is distilled water; drying, and pre-sintering at 900DEG C in the air for 6 hours; adding an adhesive into the pre-sintered powder, granulating, and pressing for formation; and sintering at the temperature of between 950 and 1,050DEG C in the air for 4 hours, wherein the adhesive is a 5 mass percent polyvinyl alcohol solution and is 3 percent of the total weight of the pre-sintered powder. The ceramic is well sintered at the temperature of between 950 and 1,050DEG C, has the dielectric constant of 32-40, the quality factor Qf value of 60,000-100,000GHz, small temperature coefficient of resonance frequency, and great application value in industry.

The invention discloses a low-temperature sintering temperature-stable microwave dielectric ceramic and a preparation method thereof. The composition formula of the low-temperature sintering temperature-stable microwave dielectric ceramic is Bi14W2O27. The preparation method comprises the steps of (1) weighing and batching original powder of Bi2O3 and WO3 with the purity being over 99.9% according to the chemical formula Bi14W2O27; (2) carrying out wet ball-milling and mixing on raw materials obtained in the step (1) for 12 hours, taking distilled water as a solvent, drying, and then, pre-sintering in an air atmosphere for 6 hours at the temperature of 700 DEG C; (3) adding a binder into powder prepared in the step (2), granulating, then, carrying out compression molding, and finally, sintering in the air atmosphere for 4 hours at the temperature of 800-820 DEG C, wherein a polyvinyl alcohol solution with the mass concentration of 5% is adopted as the binder, and the dosage of the binder accounts for 3% of the total mass of the powder. According to the ceramic prepared by the preparation method, the sintering at the temperature of 800-820 DEG C is good, the dielectric constant reaches 12-13, the quality factor (Qf) reaches up to 61,000-84,000GHz, the temperature coefficient of resonance frequency is small, and the ceramic can be subjected to low-temperature co-sintering together with a Ag electrode, so that the ceramic has a great application value in industries.

The invention relates to a barium-zinc-niobium series microwave dielectric ceramic and a method for preparing the same, which belong to the technical field of microwave dielectric material production. The ceramic comprises the chemical component of Ba(Zn1/3Nb2/3)O3-XMO(M represents Co, Cu and 2/3B), the mol ratio of Ba(Zn1/3Nb2/3)O3 to MO is 1 to X, and X is between 0.001 and 0.02. According to certain proportion, nitrate, oxalate and citric acid are dissolved into deionized water, and the pH value of the mixed solution is adjusted to between 5 and 8 by ammonia so as to form sol; the sol is dried to be dry gel which is subjected to calcining to form active powder; and the powder is shaped through wet milling and press, and is prepared into the microwave dielectric ceramic by sintering in a high-temperature furnace. The microwave dielectric ceramic can be sintered at different sintering temperatures of between 1,000 and 1,400 DEG C, has medium dielectric constant of between 20 and 40 and high quality factor with Q x f value of between 25,000 and 70,000GHz , and is expected to be widely used for manufacture of various microwave devices.

The invention discloses microwave dielectric ceramic BaCu2V2O8 with a low temperature sintering function and a preparation method thereof. The microwave dielectric ceramic BaCu2V2O8 with the low temperature sintering function comprises BaCu2V2O8. The preparation method comprises the following steps of: (1) weighing and burdening raw powder containing BaCO3, CuO and V2O5 and having the purity of 99.9 percent according to a BaCu2V2O8 chemical formula; (2) carrying wet ball-grinding and mixing for 12 hours, drying and then presintering for 6 hours in an atmosphere of 600 DEG C, wherein the solvent is distilled water; (3), adding a binder, granulating, then carrying out compression molding and finally sintering for 4 hours in an atmosphere of 650-680 DEG C, wherein the binder is a polyvinyl alcohol solution with the mass concentration of 5 percent and accounts for 3 percent by total mass of the powder. The ceramic prepared by using the preparation method has a favorable sintering property at 650-680 DEG C, the dielectric constant reaching 19-20, the quality factor Qf up to 67000-86000GHz and small temperature coefficient of resonance frequency, can be co-sintered with an Ag electrode at low temperature and has a great application value in the industry.

The invention discloses a low-temperature sinterable microwave dielectric ceramic SrCuV2O7 and a preparation method thereof. The chemical composition of the low-temperature sinterable microwave dielectric ceramic is SrCuV2O7. The preparation method comprises the following steps: (1) weighing and proportioning SrCO3, CuO and V2O5 original powder with the purity of higher than 99.9% according to the chemical formula SrCuV2O7; (2) carrying out wet-type ball milling mixing on the raw materials in the step (1) for 12 hours by using distilled water as a solvent, drying, and presintering at 600 DEG C in air for 6 hours; and (3) adding an adhesive into the powder prepared in the step (2), granulating, carrying out compression molding, and finally, sintering at 810-840 DEG C in air for 4 hours, wherein the adhesive is a 5 wt% polyvinyl alcohol solution, and accounts for 3 wt% of the powder. The ceramic disclosed by the invention can be well sintered at 810-840 DEG C; the dielectric constant is up to 15-16, the quality factor Qf is up to 54000-65000 GHz, and the temperature coefficient of resonance frequency is small; and thus, the ceramic has great application value in industry.

The invention discloses low-temperature sintering tungstate microwave dielectric ceramic Li3R3W2O12 and a preparation method thereof. The low-temperature sintering tungstate microwave dielectric ceramic material comprises the components of Li3R3W2O12, wherein R is one of Nd, La and Sm. The method comprises the steps of (1) weighing and dosing the original powder of Li2CO3, R2O3 and WO3, of which the purity is more than 99.9% according to the chemical formula of Li3R3W2O12, wherein R is one of Nd, La and Sm; (2) mixing the materials for 12 hours in a wet ball grinding manner, wherein the solvent is distilled water, and pre-sintering for 6 hours after baking in the atmosphere of 800 DEG C; and (3) adding a binder to the prepared powder and pelletizing, then pressing and molding, and finally sintering for 4 hours in the atmosphere of 850-900 DEG C, wherein the binder adopts polyvinyl alcohol solution of which the mass concentration is 5%; and the dosage is 3% of the total weight of the powder. The ceramic prepared by the preparation method has good sintering property at 850-900 DEG C; the dielectric constant achieves 20-22; the quality factor Qf value can be up to 57000-76000GHz; and the resonant frequency temperature coefficient is small.

The invention discloses microwave dielectric ceramic Ba6W2V2O17 capable of being sintered at a low temperature and a preparation method thereof. The microwave dielectric ceramic capable of being sintered at the low temperature has the composition of Ba6W2V2O17. The preparation method comprises the following steps: (1) weighing and batching original powder of BaCO3, WO3 and V2O5 with the purity of over 99.9 percent according to the chemical formula of the Ba6W2V2O17; (2) mixing the raw materials of the step (1) and performing wet milling for 12 hours, wherein the solvent is distilled water; pre-sintering for 6 hours in air atmosphere at 830 DEG C after the mixture is dried; (3) adding an adhesive into the prepared powder, granulating, pressing, forming, and sintering for 4 hours in the air atmosphere at 920 DEG C, wherein the adhesive adopts a polyvinyl alcohol solution with the mass concentration of 5 percent, and the dosage of the polyvinyl alcohol solution accounts for 3 percent of the total mass of the powder. The ceramic prepared by the invention is sintered well between 890 and 920 DEG C, has the dielectric constant between 25 and 26, the Qf (quality factor) value between 88,000 and 94,000 GHz, and low temperature coefficient of resonance frequency, can be co-fired with an Ag electrode, and has a great application value in industry.

The invention relates to the field of microwave medium ceramic of material science, in particular to Ba(Zn1/3Nb2/3)O3(BZN)-based microwave medium ceramic sintered by low-temperature reaction and a preparation method thereof. The method comprises the following steps of: adding the following additives in percentage by mass into a Ba(Zn1/3Nb2/3)O3(BZN) base material: 0.5 to 1.5 percent of CuO, 0.5 to 1.5 percent of Li2CO3, 0.5 to 1.5 percent of V2O5 and 1.5 to 4.5 percent of ZnO-B2O3; and performing common ball-milling and mixing, drying, screening and compression molding on the mixture, and then obtaining a dense ceramic product by reacting and sintering the mixture, wherein the sintering temperature can be reduced to 950 DEG C. The microwave medium ceramic has good microwave performance, and reduces the energy consumption and the cost.

The invention discloses an application of a composite oxide TiP2O7 in serving as low-temperature sintering available microwave dielectric ceramic with ultralow dielectric constant. The method comprises the following steps: (1) weighing and blending original powder, having the purity of over 99.9 percent, of TiO2 and NH4H2PO4 according to a chemical formula of TiP2O7; (2) carrying out wet ball-milling and mixing on the raw materials in the step (1) for 12 hours with ethanol serving as a ball-milling medium, baking, and pre-sintering for 6 hours in the atmosphere at 750 DEG C; and (3) adding adhesive into the powder prepared in the step (2), granulating, pressing to mold, and finally sintering for 4 hours in the atmosphere at 810-830 DEG C, wherein the adhesive is a 5% polyvinyl alcohol solution, and accounts for 3 percent of the total mass of the powder. According the ceramic prepared by the method, the sintering at 810-830 DEGC is excellent, the quality factor Qf value is up to 100,000-127,000GHz when the dielectric constant is 10-11, the temperature coefficient of resonance frequency is small, and the microwave dielectric ceramic has a great application value in industry.

The invention discloses a high-dielectric-constant lithium-niobium-titanium-based low-temperature-fired microwave dielectric ceramic material and a preparation method thereof. The material disclosed by the invention can be prepared through the solid-phase reaction of a lithium-rich lithium-niobium-titanium-based material and a lithium borosilicate glass burning improver of an amount accounting for 1-10% by weight of a main crystal phase. The composition of the lithium-rich lithium-niobium-titanium-based material is Li1.0+xNb0.6Ti0.5O3-yLBS, wherein the LBS is the lithium borosilicate glass burning improver, x is not smaller than 0 but not greater than 0.2 (mole ratio), and y is not smaller than 0 but not greater than 0.1 (weight ratio). The LBS is prepared from the following raw materials: lithium carbonate (Li2CO3), silicon dioxide (SiO2) and boron oxide (B2O3). The low-temperature-fired microwave dielectric ceramics LTCC (Low-Temperature Co-fired Ceramics) prepared by the method have the advantages that the firing at the temperature of 850-900 DEG C is good, the high dielectric constant [epsilon]r is 65-70, the quality factor Qf is moderate, and the temperature coefficient of resonance frequency is small; the ceramics can be applied to the production of microwave devices, such as LTCC systems, multilayer dielectric resonators, microwave antennae, wave filters and the like, and have great application values in industry.

The invention discloses microwave dielectric ceramic BiNbW2O10 capable of being sintered at low temperature and a preparation method thereof. The composition of the microwave dielectric ceramic capable of being sintered at low temperature is BiNbW2O10. The preparation method comprises the following steps of: (1) weighing the original powder of Bi2O3, Nb2O5 and WO3 having the purity of more than 99.9% according to the chemical formula BiNbW2O10, and mixing all the original powder together; (2) performing mixing and wet ball milling on the raw materials of the step (1) for 12 hours while taking distilled water as a solvent, and pre-sintering for 6 hours in atmosphere at 850 DEG C; (3) adding a binder to the powder obtained in the step (2) and pelleting, then carrying out compression molding, and finally sintering for 4 hours in atmosphere at the temperature ranging from 900 to 930 DEG C, wherein the binder is a polyvinyl alcohol solution having the mass concentration of 5%, and the dosage of the binder is 3% of the total weight of the powder. The ceramic prepared by the preparation method disclosed by the invention is well sintered at the temperature ranging from 900 to 930 DEG C; the dielectric constant of the ceramic is in the range from 17 to 18, the value of the quality factor Qf of the ceramic is within the range from 86000 to 98000 GHz and the temperature coefficient of resonant frequency of the ceramic is low; the ceramic can be co-sintered at the low temperature with an Ag electrode and has an enormous application value in industry.

The invention discloses microwave dielectric ceramic BaV2Nb2O11 capable of sintering at a low temperature and a preparation method thereof. The microwave dielectric ceramic capable of being sintered at the low temperature has the composition of BaV2Nb2O11. The preparation method comprises the following steps: (1) weighing and batching original powder of BaCO3, V2O5 and Nb2O5 with the purity over 99.9 percent according to the chemical formula of the BaV2Nb2O11; (2) mixing the raw materials of the step (1) and performing wet milling for 12 hours, wherein the solvent is distilled water; pre-sintering for 6 hours in air atmosphere at 750 DEG C after the mixture is dried; (3) adding an adhesive into the prepared powder, granulating, pressing, forming, and sintering for 4 hours in the air atmosphere at the temperature between 810 and 840 DEG C, wherein the adhesive adopts a polyvinyl alcohol solution with the mass concentration of 5 percent, and the dosage of the polyvinyl alcohol solution accounts for 3 percent of the total mass of the powder. The ceramic prepared by the invention is sintered well between 810 and 840 DEG C, has the dielectric constant between 35 and 36, the Qf (quality factor) value of between 81,000 and 95,000 GHz, and low temperature coefficient of resonance frequency, can be co-fired with an Ag electrode, and has a great application value in industry.