Microwave dielectric ceramic BaLi2Ge7O16 capable of being sintered at low temperature and preparation method thereof

Abstract

The invention discloses high-quality-factor, stable-temperature and ultra-low-dielectric-constant microwave dielectric ceramic BaLi2Ge7O16 capable of being sintered at low temperature and a preparation method thereof. Firstly, original powder of CaCO3, Li2CO3 and GeO2 with purity being 99.9% (by weight percentage) is weighed and matched according to composition of BaLi2Ge7O16; secondly, the raw materials in the first step are mixed for 12 h in a raw material wet ball mill, ball milling media are distilled water, and pre-sintering is performed for 6 h in 750 DEG C atmosphere after drying; thirdly, after an adhesion agent is added in the powder prepared in the second step and pelleting is performed, pressing and forming are performed, and finally, sintering is performed for 4 h in 800-850 DEG C atmosphere; a polyvinyl alcohol solution with the mass concentration being 5% is adopted as the adhesion agent, and the adding amount of polyvinyl alcohol accounts for 3% of the total mass of the powder. The prepared ceramic can be well sintered at 850 DEG C, the dielectric constant reaches 16.1-16.9, the quality factor Qf of the ceramic reaches as high as 74000-121000 GHz, the resonant frequency temperature coefficient is small, and the ceramic has great application value industrially.

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

Images