Temperature-stable microwave dielectric ceramic Bi2TiGe3O11 allowing low temperature sintering and preparation method thereof

Abstract

The invention discloses a temperature-stable microwave dielectric ceramic Bi2TiGe3O11 allowing low temperature sintering and a preparation method thereof. The method is as below: (1) weighing analytically pure raw materials of Bi2O3, TiO and GeO2 powders according to a stoichiometric formula Bi2TiGe3O11; (2) mixing the raw materials in the step (1) by wet ball milling for 12 h by using a milling medium of distilled water, drying and pre-sintering in the atmosphere at 700 DEG C for 6 h; and (3) adding a binder into the powder obtained in the step (2) and pelletizing, then pressing for forming, and finally sintering in the atmosphere at 750-800 DEG C for 4 h, wherein the binder is a polyvinyl alcohol solution with mass concentration of 5%, and the addition of the polyvinyl alcohol accounts for 3 wt.% of the total amount of the powder. The ceramic prepared by the invention has the advantages of good sintering property at the temperature below 800 DEG C, dielectric constant of 16.7-17.8, quality factor Qf of up to 84000-141000 GHz, small resonance frequency temperature coefficient, and a great application value in industry.

Description

technical field [0001] The invention relates to a dielectric ceramic material, in particular to a dielectric ceramic material for manufacturing microwave components such as ceramic substrates, resonators and filters used in microwave frequencies and a preparation method thereof. Background technique [0002] Microwave dielectric ceramics refer to ceramics that are used as dielectric materials in circuits in the microwave frequency band (mainly UHF and SHF bands) and perform one or more functions. They are widely used as resonators, filters, and dielectric substrates in modern communications. Components such as chips and dielectric waveguide circuits are the key basic materials of modern communication technology. They have been used in portable mobile phones, car phones, cordless phones, TV satellite receivers and military radars. They are used in modern communication tools. It is playing an increasingly important role in the process of miniaturization and integration. [00...

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Problems solved by technology

[0009] In the process of exploring and developing new low-firing microwave dielectric ceramic materials, material systems such as Li-based compounds, Bi-based compounds, tungstate compounds and tellurate-based compounds with inherently low sintering temperatures have received extensive attention and research. However, due to the three performance indicators of microwave dielectric ceramics (ε r with Q f and τ ? ) is a mutually restrictive relationship (see literature: The restrictive relationship between the dielectric properties of microwave dielectric ceramic materials, Zhu Jianhua, Liang Fei, Wang Xiaohong, Lu Wenzhong, Electronic Components and Materials, Issue 3, March 2005), satisfying three There are very few single-phase microwave dielectric ceramics that require high performance and can be sintered at low temperature, mainly because their resonant frequency temperature coefficient is usually too large or the quality factor is too low to meet the practical application requirements.

At present, most of the research on microwave dielectric ceramics is a summary of experience obtained through a large number of experiments, but there is no complete theory to explain the relationship between microstructure and dielectric properties. Predict the microwave dielectric properties such as its resonant frequency temperature coefficient and quality factor, which largely limits the development of low temperature co-firing technology and microwave multilayer devices

Exploring and developing microwave dielectric ceramics that can be sintered at low temperature and have near-zero resonant frequency temperature coefficient (-10ppm / ℃≤τ?≤+10ppm / ℃) and high quality factor is the technology in this field A difficult problem that people have always wanted to solve but have never been able to succeed in

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