High-quality-factor low-dielectric-constant microwave dielectric ceramic Ca3Bi2V2O11

Abstract

The invention discloses a high-quality-factor low-dielectric-constant microwave dielectric ceramic Ca3Bi2V2O11 and a preparation method thereof. The method includes: (1) weighing and mixing original powder of V2O5, Bi2O3 and CaO with the purity higher than 99.9% (weight percentage) according to composition of Ca3Bi2V2O11; (2) subjecting the materials at the step (1) to wet ball-mill mixing for 12h with distilled water serving as a ball milling medium, drying, and pre-sintering for 6h in the air atmosphere of 800 DEG C; (3) adding a binding agent into powder obtained at the step (2), performing pelletizing and compression molding, and finally sintering for 4h in the air atmosphere of 850-900 DEG C, wherein a polyvinyl alcohol solution with the mass concentration being 5% serves as the binding agent, and addition amount of the polyvinyl alcohol accounts for 3% of the total mass of the powder. The prepared microwave dielectric ceramic Ca3Bi2V2O11 is excellent in sintering below 900 DEG C, is 24.1-25.4 in dielectric constant and up to 111000-142000GHz in quality factor Qf value and is low in temperature coefficient of resonance frequency, thereby being extremely high 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 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] Dielectric ceram...

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