Gallate ultra-low dielectric constant microwave dielectric ceramic

Abstract

The invention discloses a gallate temperature-stable ultra-low dielectric constant microwave dielectric ceramic Li3W2Ga3O12 and a preparation method thereof. The method comprises the steps of (1) weighing and burdening original powder of Li2CO3, WO3 and Ga2O3, of which the purity is greater than 99.9% (percentage by weight) according to composition of the Li3W2Ga3O12; (2) carrying out wet ball-mill mixing on the raw materials in the step (1) for 12h, wherein the ball-milling medium is distilled water, drying and then pre-sintering in an air atmosphere of 1100 DEG C for 6h; and (3) adding a binder to the powder prepared in the step (2), granulating, carrying out compression moulding and finally sintering in the air atmosphere of 1150-1200 DEG C for 4h, wherein a polyvinyl alcohol solution with the mass concentration of 5% is adopted by the binder and the additive amount of polyvinyl alcohol accounts for 3% of total mass of the powder. The prepared ceramic has good sintering property below 1200 DEG C, the dielectric constant reaches 9.6-10.3, the quality factor Qf value reaches 81,000-102,000GHz, the temperature coefficient of the resonance frequency is small and the prepared ceramic has 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 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 f ) 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 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

Exploration and development can not only sinter at low temperature but also have near-zero resonance frequency temperature coefficient (-10ppm / ℃≤τ f ≤+10ppm / °C) 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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