Low dielectric constant microwave dielectric ceramic bi2mgw5o19 that can be sintered at low temperature

Abstract

The invention discloses low-temperature sinterable temperature-stable microwave dielectric ceramic Bi2MgW5O19 with a low dielectric constant, and a preparation method of the microwave dielectric ceramic Bi2MgW5O19. The method comprises the following steps: (1) weighing and burdening original powder of Bi2O3, MgO and WO3 with the purities being over 99.9% (mass percent) according to the components of Bi2MgW5O19; (2) carrying out wet ball-milling and mixing on the raw materials in the step (1) for 12 hours, wherein the ball-milling medium is distilled water, drying and then presintering in atmosphere at 800 DEG C for 6 hours; and (3) adding a binder to the powder prepared in the step (2), pelletizing, pressing and molding, and finally sintering in atmosphere at 850-880 DEG C for 4 hours, wherein the binder is a polyvinyl alcohol solution with the mass concentration being 5%, and the adding amount of polyvinyl alcohol accounts for 3% of total mass of the powder. The ceramic prepared by the method is good in sintering property at 850-880 DEG C, the dielectric constant reaches 25.4%-26.3%, the quality factor Qf value can reach 57,000-66,000GHz, the temperature coefficient of the resonance frequency is small, and the microwave dielectric ceramic Bi2MgW5O19 has great 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...

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Problems solved by technology

[0009] In the process of exploring and developing new low-fire microwave dielectric ceramic materials, Li-based compounds, Bi-based compounds, tungstate system compounds and Material systems such as tellurate system compounds have been widely concerned and studied, but due to the three performance indicators of microwave dielectric ceramics (εr and Q f and τ? ) is a mutual 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 be practically produced and applied.

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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