Temperature stable low dielectric constant microwave dielectric ceramic LiSrSmV2O8

Abstract

The invention discloses a low loss and high thermal stability tetragonal zirconia structure low dielectric constant microwave dielectric ceramic LiSrSmV2O8 and a preparation method thereof. The method includes: (1) weighing Li2CO3, SrCO3, Sm2O3 and V2O5 original powder with purity of over 99.9% (weight percentage) according to the composition of LiSrSmV2O8; (2) subjecting the raw materials of step (1) to wet ball-milling mixing for 12h, taking distilled water as the ball-milling medium, performing drying, then conducting presintering in 750DEG C air atmosphere for 6h; and (3) adding a binder into the powder prepared in step (2) and conducting granulation, then performing compression moulding, and finally conducting sintering in 800-850DEG C air atmosphere for 4h. The binder adopts a polyvinyl alcohol solution with a mass concentration of 5%, and the adding amount of polyvinyl alcohol accounts for 3% of the total mass of the powder. The ceramic prepared by the method provided by the invention can be well sintered below 850DEG C, and has a dielectric constant up to 21.1-21.7, a quality factor Qf value up to 117000-155000GHz and a small temperature coefficient of resonant frequency, thus having enormous 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 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...

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

Images