Microwave dielectric ceramic Bi2ZnW4O16 with low dielectric constant and capacity of low temperature sintering

Abstract

The invention discloses a temperature stabilization type microwave dielectric ceramic Bi2ZnW4O16 with low dielectric constant and capacity of low temperature sintering as well as a preparation method thereof. The method comprises the steps as follows: (1), original powder of Bi2O3, ZnO and WO3 with the purity higher than 99.9% in percentage by weight is weighed and prepared according to composition of Bi2ZnW4O16; (2), raw materials in the step (1) are subjected to wet type ball milling and mixing for 12 hours, the ball milling medium is distilled water, and the mixture is pre-sintered for 6 hours in the air atmosphere at the temperature of 750 DEG C after dried; and (3), the powder prepared in the step (2) is added with a binding agent, pelletized, subjected to compression moulding and sintered for 4 hours in the air atmosphere at the temperature of 800 DEG C-840 DEG C finally, the binding agent adopts a polyvinyl alcohol solution with the mass concentration of 5%, and the adding amount of polyvinyl alcohol accounts for 3% of the total mass of the powder. The prepared ceramic is well sintered at the temperature of 800 DEG C-840 DEG C, the dielectric constant reaches 27.4-28.3, the value of quality factor (Qf) is up to 47,000-62,000 GHz, the temperature coefficient of resonance frequency is small, and the ceramic has a great 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 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-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 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

Explore and develop low-temperature sintering and near-zero resonant frequency temperature coefficient (-10 ppm / ℃≤τ ? ≤+10 ppm / ℃) and high quality factor microwave dielectric ceramics are difficult problems that those skilled in the art have been eager to solve but have always been difficult to achieve

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