Low-dielectric-constant microwave dielectric ceramic with excellent temperature stability, and preparation method thereof

A technology of microwave dielectric ceramics and low dielectric constant is applied in the field of ceramic materials, which can solve problems such as restricting commercial application, and achieve the effects of low raw material cost, low production cost and simple method.

CN111592348AInactive Publication Date: 2020-08-28HANGZHOU DIANZI UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2020-08-28
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a low-dielectric-constant microwave dielectric ceramic with excellent temperature stability, and a preparation method thereof. The chemical formula of the microwave dielectricceramic is CaAl2-2xTixO4-x (x is greater than or equal to 0 and less than or equal to 0.1), and the main raw materials are high-purity CaCO3, Al2O3 and TiO2 powder. The preparation method adopting a traditional solid-phase sintering method is adopted comprises the following steps: accurately weighing the high-purity raw material powder according to the chemical formula CaAl2-2xTixO4-x, and fully grinding; calcining the prepared powder for 3 hours at the temperature of 1200-1250 DEG C; and finally, pressing the calcined powder into a ceramic green body, and sintering the ceramic green body in an air environment at 1400-1475 DEG C for 3 hours to obtain a ceramic sintered body. The microwave dielectric ceramic provided by the invention has a relatively low dielectric constant and excellent quality factor and temperature stability, and can be used as a core dielectric material of microwave devices such as dielectric resonators, filters and antennas in a 5G millimeter wave communication system.
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Description

technical field

[0001] The invention belongs to the technical field of ceramic materials, and specifically relates to a low dielectric constant microwave dielectric ceramic with excellent temperature stability and a preparation method thereof, which is the core of microwave devices such as dielectric resonators, filters, and antennas in 5G millimeter wave communication systems medium material. Background technique

[0002] Microwave dielectric ceramics refer to low-loss, temperature-stable ceramics that are used as dielectric materials in microwave frequency (300MHz-300GHz) circuits and perform one or more functions. With the rapid development of wireless communication technology, microwave dielectric ceramics have been widely concerned as the key materials of microwave resonator devices (including dielectric resonators, filters, oscillators), microwave capacitors and other passive devices. In recent years, with the continuous improvement of people's requirements for inform...

Examples

Embodiment 1

[0052] The microwave dielectric ceramic CaAl of the present embodiment 2-2x Ti x o 4-x (x=0.025) preparation method, comprises the following steps:

[0053] (1) Ingredients: CaCO 3 (purity 99.99%), Al 2 o 3 (purity 99.99%), TiO 2 (purity 99.99%) according to CaAl 1.95 Ti 0.025 o 3.975 stoichiometric ratio.

[0054] (2) Mixing: Pour the above-mentioned mixture into a ball mill, add ball milling medium and absolute ethanol respectively at a mass ratio of 1:5:3, place in a planetary ball mill, and ball mill for 6 hours at a speed of 180r / min to obtain slurry;

[0055] (3) Drying: Pour out the ball-milled slurry, place it in an oven and dry it to constant weight at 70°C to obtain a dry mixture;

[0056] (4) Pre-calcination: Grind the dry mixture obtained in the previous step in a mortar and pass it through a 100-mesh standard sieve. After dispersing the mixture, put it into a high-temperature furnace for pre-calcination for 3 hours. The pre-calcination temperature is 12...

Embodiment 2

[0064] The microwave dielectric ceramic CaAl of the present embodiment 2-2x Ti x o 4-x (x=0.05) preparation method, comprises the following steps:

[0065] (1) Ingredients: CaCO 3 (purity 99.99%), Al 2 o 3 (purity 99.99%), TiO 2 (purity 99.99%) according to CaAl 1.9 Ti 0.05 o 3.95 stoichiometric ratio.

[0066] (2) Mixing: Pour the above-mentioned mixture into a ball mill, add ball milling medium and absolute ethanol respectively at a mass ratio of 1:5:3, place in a planetary ball mill, and ball mill for 6 hours at a speed of 180r / min to obtain slurry;

[0067] (3) Drying: Pour out the ball-milled slurry, place it in an oven and dry it to constant weight at 70°C to obtain a dry mixture;

[0068] (4) Pre-calcination: Grind the dry mixture obtained in the previous step in a mortar and pass it through a 100-mesh standard sieve. After dispersing the mixture, put it into a high-temperature furnace for pre-calcination for 3 hours. The pre-calcination temperature is 1250 °...

Embodiment 3

[0076] The microwave dielectric ceramic CaAl of the present embodiment 2-2x Ti x o 4-x (x=0.075) preparation method, comprises the following steps:

[0077] (1) Ingredients: CaCO 3 (purity 99.99%), Al 2 o 3 (purity 99.99%), TiO 2 (purity 99.99%) according to CaAl 1.85 Ti 0.075 o 3.925 stoichiometric ratio.

[0078] (2) Mixing: Pour the above-mentioned mixture into a ball mill, add ball milling medium and absolute ethanol respectively at a mass ratio of 1:5:3, place in a planetary ball mill, and ball mill for 6 hours at a speed of 180r / min to obtain slurry;

[0079] (3) Drying: Pour out the ball-milled slurry, place it in an oven and dry it to constant weight at 70°C to obtain a dry mixture;

[0080] (4) Pre-calcination: Grind the dry mixture obtained in the previous step in a mortar and pass it through a 100-mesh standard sieve. After dispersing the mixture, put it into a high-temperature furnace for pre-calcination for 3 hours. The pre-calcination temperature is 12...