High-quality-factor temperature-stable microwave dielectric ceramic Li2ZnGe2O6 and preparation method thereof

Abstract

The invention discloses high-quality-factor temperature-stable microwave dielectric ceramic Li2ZnGe2O6 and a preparation method thereof. The preparation method comprises the following steps: (1) weighing and blending initial powder of Li2CO3, ZnO and GeO2 of which the purity reaches 99.9% by weight percent according to a composition of Li2ZnGe2O6; (2) conducting wet-type ball milling on the raw materials obtained in the step (1) for 12 hours, and carrying out 6 hours' pre-sintering in an atmosphere of 800 DEG C after drying, wherein distilled water is adopted as a ball milling medium; (3) adding a bonding agent into the powder obtained in the step (2) for pelletization, carrying out compression moulding, and finally carrying out 4 hours' sintering in an atmosphere of 850-900 DEG C, wherein a polyvinyl alcohol solution with the mass concentration of 5% is adopted as the bonding agent, and the adding amount of polyvinyl alcohol accounts for 3% of the total mass of the obtained powder. The prepared microwave dielectric ceramic can be well sintered at 900 DEG C or below, the dielectric constant reaches 15.7-16.9, the quality factor, namely the Qf value, reaches up to 91000-155000 GHz, the temperature coefficient of resonance frequency is small, and the industrial application value is high.

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...

AI Technical Summary

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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