Temperature-stable microwave dielectric ceramic LiGeV3O10 and preparation method therefor

Abstract

The invention discloses a high-quality-factor temperature-stable low-dielectric-constant microwave dielectric ceramic LiGeV3O10 and a preparation method therefor. The preparation method comprises the following steps: (1) weighing and batching raw powder of Li2CO3, V2O5 and GeO2, the purity of which is 99.9% (percentage by weight) according to constitution of the LiGeV3O10; (2) performing wet-type ball-milling mixing on the raw materials obtained in the step (1) for 12 hours by using a ball-milling medium of distilled water, drying and pre-baking the powderfor 6 hours in an air atmosphere at the temperature of 650 DEG C; and (3) adding an adhesive into the powder prepared in the step (2), granulating the powder, performing compression molding and finally sintering on the powder for 4 hours in the air atmosphere at the temperature of 700 to 750 DEG C, wherein the adhesive is a polyvinyl alcohol solution, the concentration by mass of which is 5%, and the amount of added polyvinyl alcohol is 3% of the total mass of the powder. The ceramic prepared by the method disclosed by the invention is well sintered at 750 DEG C, is as high as 25.4 to 26.8 in dielectric constant, is as high as 79000GHz to 105000GHz in quality factor Qf value, small in temperature coefficient of resonance frequency and extremely large in industrial application value.

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 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. [0003] Dielectr...

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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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