Low-dielectric-constant microwave dielectric ceramic Na2Zn2TiGeO7 and preparation method thereof

Abstract

The invention discloses low-dielectric-constant microwave dielectric ceramic Na2Zn2TiGeO7 and a preparation method thereof. The preparation method comprises the steps that 1, chemical raw materials including Na2CO3, ZnO, TiO2 and GeO2 powder are weighed and blended according to the chemical stoichiometric equation Na2Zn2TiGeO7; 2, the raw materials in the step 1 are subjected to wet ball milling and mixing for 12 hours, distilled water serves as a ball milling medium, and the powder is pre-sintered for 6 hours in an air atmosphere at the temperature of 850 DEG C; 3, a binding agent is added to the powder obtained in the step 2, pelleting is carried out, then compression moulding is carried out, finally sintering is carried out for 4 hours in an air atmosphere at the temperature of 900 DEG C to 950 DEG C, a polyvinyl alcohol solution with the mass concentration of 5% serves as the binding agent, and the adding amount of polyvinyl alcohol accounts for 3% of the total mass of the powder. The ceramic is sintered well at the temperature of 1,000 DEG C or below, the dielectric constant ranges from 21.6 to 22.3, the quality factor Qf value of the ceramic reaches 64,200 GHz to 79,100 GHz, the temperature coefficient of resonance frequency is small, and the ceramic has high 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...

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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