Ultralow-loss yttrium aluminum garnet microwave dielectric ceramic material and preparation method thereof

A technology of microwave dielectric ceramics and yttrium aluminum garnet, which is applied in the field of preparation of electronic information functional materials, can solve the problems of low relative density, high difficulty, dielectric loss, etc., and achieve the effect of stable performance and improved performance

Active Publication Date: 2021-02-05
UNIV OF ELECTRONICS SCI & TECH OF CHINA
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  • Abstract
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Problems solved by technology

And by doping 1wt% Nb2O5, the microwave dielectric properties of yttrium aluminum garnet microwave are partially improved: εr= 11.2, Q×f=120000GHz, τf=-48ppm / ℃, the value of Q×f has been significantly improved, but the value of Q×f is still low, because the relative density of this sample is too high The low is only 96%, there are a lot of pores inside, resulting in serious dielectric loss
Later, "Journal of the European Ceramic Society" (Journal of the European Ceramic Society) 2015 article "SPS sintering parameters, LiF additives and Nd doping on the microwave dielectric and optical properties of transparent YAG ceramics" (Effect of the spark plasma sintering parameters, LiF additive, and Nd dopant on the microwavedielectric and optical properties of transparent YAG ceramics) reported that nano-YAG powder was prepared by thermal decomposition, and then co-doped with TEOS and TiO2, in 1520 Sintered at ℃ for 5 hours to obtain yttrium aluminum garnet microwave dielectric ceramics, the relative density is 97.6%, and the microwave dielectric properties are: εr=9.9, Q×f=71700GHz, τf=-30ppm / ℃, the relative density and performance have not been significantly improved
[0005] It can be seen from this that in the above-mentioned research on YAG microwave dielectric ceramics, whether the traditional solid-state reaction method is used or the micron-submicron ceramic powder is obtained by ball milling It is still difficult to prepare high-quality YAG ceramics with high relative density (≥99.5%), no porosity, and few impurities, or the preparation of nano-powder by wet chemical method, resulting in low Q×f value (≤120000GHz)
, Not only that, because YAG is a stoichiometric crystal, its ratio is very precise, Y / Al=3 / 5, so it is very difficult to prepare YAG ceramics, which will lead to non-stoichiometric materials during the preparation process

Method used

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  • Ultralow-loss yttrium aluminum garnet microwave dielectric ceramic material and preparation method thereof
  • Ultralow-loss yttrium aluminum garnet microwave dielectric ceramic material and preparation method thereof
  • Ultralow-loss yttrium aluminum garnet microwave dielectric ceramic material and preparation method thereof

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Experimental program
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Effect test

Embodiment 1

[0037] Step 1: put Y 2 o 3 、Al 2 o 3 , MgO, SiO 2 、TiO 2 , prepare materials according to the mass ratio of 56.7%, 42.6%, 0.2%, 0.3%, 2.4%, 0.2% and 0.3% respectively;

[0038] Step 2: a ball mill; the obtained mixture is milled with alumina balls as the ball milling medium, and absolute ethanol is used as the solvent, and ground for 24 hours according to the weight ratio of mixture: balls: ethanol is 1:5:2, and finally to obtain a homogeneous mixture;

[0039] Step 3: drying and sieving; the ball-milled mixture is dried at 70°C and passed through a 100-mesh sieve to obtain a dry powder;

[0040] Step 4: Pre-firing; put the dry powder obtained in Step 3 in an alumina crucible, and then pre-fire and keep it warm at 1100°C for 3 hours to obtain a sample briquette;

[0041] Step 5: secondary ball milling; the pre-burnt powder obtained in step 4 is ball milled for the second time, with alumina balls as the ball milling medium, and ground according to the mass ratio of powder:...

Embodiment 2

[0047] Step 1: put Y 2 o 3 、Al 2 o 3 , Ga 2 o 3 , prepare materials according to the mass ratio of 56.9%, 42.6% and 0.5% respectively;

[0048] Step 2: a ball mill; use alumina balls as the ball milling medium, and grind for 24 hours according to the mass ratio of mixture: balls: alcohol to obtain a uniformly mixed ball mill;

[0049] Step 3: drying and sieving; drying the ball mill material obtained in step 2 at 70°C and passing through a 100-mesh sieve to obtain a dry powder;

[0050] Step 4: Pre-calcining; the dry powder obtained in Step 3 is placed in an alumina crucible, and pre-fired at 1300°C for 5 hours to obtain a pre-fired powder;

[0051] Step 5: secondary ball milling; the calcined powder obtained in step 4 is ball milled for the second time, with alumina balls as the ball milling medium, and the mass ratio of powder: ball: alcohol is 1:3:2 for grinding 12 hour to obtain a uniformly mixed secondary ball mill;

[0052] Step 6: drying and sieving; drying the ...

Embodiment 3

[0057] Step 1: put Y 2 o 3 、Al 2 o 3 , Nb 2 o 5 , prepare materials according to the mass ratio of 54.9%, 42.9% and 2.2% respectively;

[0058] Step 2: primary ball milling; use alumina balls as the ball milling medium, and grind for 20 hours according to the mass ratio of mixture: ball: alcohol: 1:7:2 to obtain a uniformly mixed ball mill;

[0059] Step 3: drying and sieving; drying the ball mill material obtained in step 2 at 70°C and passing through a 100-mesh sieve to obtain a dry powder;

[0060] Step 4: Pre-calcining; the dry powder obtained in Step 3 is placed in an alumina crucible, and pre-fired at 1200°C for 4 hours to obtain a pre-fired powder;

[0061] Step 5: secondary ball milling; the pre-burnt powder obtained in step 4 is ball milled for the second time, with alumina balls as the ball milling medium, and ground according to the mass ratio of powder: ball: alcohol of 1:5:1 for 10 hour to obtain a uniformly mixed secondary ball mill;

[0062] Step 6: dryi...

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Abstract

The invention provides an ultralow-loss yttrium aluminum garnet microwave dielectric ceramic material, the chemical general formula of the material is Y3-xAl5-yRzO12, and R is one or more selected from Mg < 2 + >, Ga < 3 + >, Si < 4 + >, Ti < 4 + > and Nb < 5 + > heterovalent ions; 0 < = x < = 0.15, 0 < = y < = 0.8 and 0.03 < = z < = 1.5; the invention also provides a preparation method of the ultralow-loss yttrium aluminum garnet microwave dielectric ceramic material. The preparation method comprises the following steps: burdening, ball milling, drying and sieving, presintering, dry pressing,isostatic cool pressing, vacuum sintering and atmosphere control annealing. The prepared material is typical ultralow-loss garnet type aluminum-based microwave dielectric ceramic, Q * f ranges from 180000 GHz to 220000 GHz, the relative dielectric constant epsilonr ranges from 8 to 12, and the frequency temperature coefficient tauf ranges from -33 ppm/DEG C to -22 ppm/DEG C. The formula does notcontain volatile toxic metals such as Pb, Cd and the like, the performance is stable, and the raw materials are sufficiently supplied in China, so that the low cost of the high-performance microwave ceramic becomes possible.

Description

technical field [0001] The invention belongs to the technical field of preparation of electronic information functional materials, and relates to a microwave dielectric ceramic material with ultra-high Q value obtained by regulating the non-stoichiometric ratio of yttrium-aluminum garnet and the content of additives and a preparation method thereof. Background technique [0002] Microwave dielectric ceramics refer to ceramics that are used as dielectric materials in microwave (300MHz~300GHz) frequency band circuits and perform one or more functions. They are key basic materials in modern communication technology and are widely used in dielectric resonators and filters. , dielectric substrate, dielectric waveguide circuit, microwave capacitor, duplexer, antenna and other microwave components. In high-frequency microwave circuits, many microwave devices need to use dielectric ceramic materials as substrates, making microwave ceramic dielectric substrate materials increasingly ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/505C04B35/622
CPCC04B35/505C04B35/622C04B2235/3206C04B2235/3418C04B2235/3232C04B2235/3217C04B2235/6562C04B2235/6567
Inventor 唐斌周沫轲李恩竹袁颖钟朝位张树人
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA
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