Coke green stone high frequency/microwave medium ceramic sintered by low temp. and preparation process thereof

A technology of microwave dielectric ceramics and low-temperature sintering, which is applied in the direction of ceramics and inorganic insulators. It can solve the problems of high sintering temperature, poor microwave dielectric properties, and easy reduction of Q value, etc., and achieve low sintering temperature, low frequency temperature coefficient, The effect of small dielectric loss

Inactive Publication Date: 2007-10-31
XI AN JIAOTONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of ZST is that the sintering temperature is high. When adding a liquid phase sintering agent, it is easy to reduce the Q value.
However, the reported microwave dielectric properties are not excellent.

Method used

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  • Coke green stone high frequency/microwave medium ceramic sintered by low temp. and preparation process thereof

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preparation example Construction

[0025] The preparation process of the present invention is, the chemical raw material Bi 2 o 3 , ZnO, Nb 2 o 5 , CaCO 3 , CdO, SrCO 3 , according to the formula (Bi 3x m 2-3x )(Zn x Nb 2-x )O 7 Preparation, where M=Zn 2+ , Ca 2+ , Cd 2+ ,Sr 2+ , 0.56≤x≤0.64; After the preparation, the ball mill is fully mixed and finely ground, passed through a 70-120 mesh sieve, pre-calcined at 750°C-850°C, and kept warm for 2-3 hours to obtain agglomerates, which are pulverized and ground again Granulate and pass through a 120-mesh sieve to obtain the desired ceramic material. After being made into a finished product as required, it is sintered into porcelain at 900°C to 1020°C to obtain low-temperature sintered pyrochlore high-frequency / microwave dielectric ceramics.

[0026] The low-temperature sintered pyrochlore high-frequency / microwave dielectric ceramics of the present invention include Bi 2 o 3 , ZnO, Nb 2 o 5 Such composition makes it possible to sinter this dielect...

Embodiment 1

[0030] The chemical raw material Bi 2 o 3 , ZnO, Nb 2 o 5 According to the formula: (Bi 3x Zn 2-3x )(Zn x Nb 2-x )O 7 , wherein, x=0.64, after the preparation is fully mixed and ball milled, passed through a 70-120 mesh sieve, pre-fired at 700°C-800°C, and kept warm for 2-3 hours to obtain a briquette, which is pulverized and ground again Granulate and pass through a 120-mesh sieve to obtain the desired ceramic material. After the porcelain material is made into a finished product as required, it is sintered into porcelain at 940°C to 1040°C to obtain low-temperature sintered pyrochlore high-frequency / microwave dielectric ceramics.

[0031] The performance of this group of ceramic materials reaches the following indicators:

[0032] Dielectric constant temperature coefficient α ε =248ppm / ℃(1MHz), dielectric constant ε=84(1MHz), dielectric loss tanδ-4 (1MHz), insulation resistivity ρ v ≥10 14 Ω·cm, good microwave performance ε=75(3~5GHz), Qf=1667.

Embodiment 2

[0034] The chemical raw material Bi 2 o 3 , ZnO, Nb 2 o 5 , CaCO 3 According to the formula: (Bi 3x Ca 2-3x )(Zn x Nb 2-x )O 7 , wherein, x=0.56, after the preparation is fully mixed and ball milled, passed through a 70-120 mesh sieve, pre-calcined at 700°C-800°C, and kept warm for 2-3 hours to obtain a briquette, which is pulverized and ground again Granulate and pass through a 120-mesh sieve to obtain the desired ceramic material. After the porcelain material is made into a finished product as required, it is sintered into porcelain at 900°C to 980°C to obtain low-temperature sintered pyrochlore high-frequency / microwave dielectric ceramics.

[0035] The performance of this group of ceramic materials reaches the following indicators:

[0036] Dielectric constant temperature coefficient α ε =214ppm / ℃(1MHz), dielectric constant ε=80(1MHz), dielectric loss tanδ-4 (1MHz), insulation resistivity ρ v ≥10 14 Ω cm, good microwave performance ε = 76 (3 ~ 5GHz), Qf = 5076,...

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Abstract

The invention discloses a low temperature sintering coke verd antique high frequency / microwave medium ceramics. The expression of the ceramics is Bi3xM2-3x)(ZnxNb2-x)O7, and M is Zn2+, Ca2+ or Cd2+, or Sr2+, and 0.5<=x<=0.64. The invention has the following feature: high dielectric constant, low medium consumption, wide covering range of temperature coefficient dielectric constant, low sintering temperature, simple technology, etc.

Description

technical field [0001] The invention belongs to the field of electronic ceramics and its manufacture, and relates to a low-temperature sintered pyrochlore high-frequency / microwave dielectric ceramic material and its preparation, as well as the application of the material to microwave devices such as ceramic antennas. Background technique [0002] In terms of mobile communication, its development is aimed at expanding higher frequency bands and increasing the carrier information capacity. On the other hand, it also puts forward requirements for portability of communication equipment systems. The whole system is moving toward integration, in order to obtain small size, light weight, High reliability, low cost products. In the process of microwave circuit integration, the emergence of metal waveguides and microwave tubes has enabled microwave circuits to be integrated and miniaturized to a certain extent, but the traditionally used bulky metal resonators...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/01C04B35/495C04B35/453C04B35/622C04B35/64H01B3/12
Inventor 汪宏张美玲姚熹
Owner XI AN JIAOTONG UNIV
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