Low-dielectric-constant microwave dielectric ceramic BaIn2ZnO5 and preparation method thereof

Abstract

The invention discloses temperature-stable type low-dielectric-constant microwave dielectric ceramic BaIn2ZnO5 and a preparation method thereof. The preparation method comprises the following steps: (1) weighing and blending original powder of BaCO3, In2O3 and ZnO of which the purity is 99.9% (percentage by weight) according to composition of BaIn2ZnO5; (2) performing wet ball-milling mixing on the raw materials obtained in the step (1) for 12 hours with distilled water as a ball milling medium, drying, and then pre-burning for 6 hours in a 1200 DEG C atmosphere; and (3) adding a bonding agent into the powder prepared in the step (2), pelleting, then performing press molding, and finally sintering for 4 hours in a 1250-1300 DEG C atmosphere, wherein the bonding agent is a polyvinyl alcohol solution with the mass concentration of 5%, and the added amount of polyvinyl alcohol accounts for 3% of the total mass of the powder. The ceramic prepared by the method disclosed by the invention is good in sintering property, the dielectric constant reaches 26.7-28.9, the quality factor Qf reaches 70000-95000 GHz, and the temperature coefficient of resonance frequency is small, so that the ceramic has great application values 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

[0008] 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 with individual performance requirements, 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, explore and develop near-zero resonant frequency temperature coefficient (-10 ppm / ℃≤τ ? ≤+10 ppm / ℃) and a series of different dielectric constants with higher quality factors microwave dielectric ceramics is a difficult problem that those skilled in the art have been eager to solve but have always been difficult to achieve, which largely limits the development of microwave dielectric ceramics. and device development

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