Low temperature sintered microwave dielectric ceramic Li2W4O13 and preparation method thereof

Abstract

The invention discloses a low temperature sintered microwave dielectric ceramic Li2W4O13 and a preparation method thereof. The chemical formula of the dielectric ceramic material is Li2W4O13. The preparation method comprises the following steps of: (1) proportioning original powder of Li2CO3 and WO3 with purity over 99.9% according to the composition of Li2W4O13; (2) mixing the raw material in step (1) by a wet ball mill for 12 hours by taking distilled water as a solvent, and drying and pre-sintering for 6 hours in atmosphere at 500 DEG C; and (3) adding an adhesive to the prepared powder obtained in step (2) and prilling, then pressing and forming, and finally, sintering for 4 hours in atmosphere at 540-560 DEG C, wherein the adhesive is a polyvinyl alcohol liquor with mass concentration of 5%, and accounts for 3% of the total weight of the powder. Ceramic prepared by the invention is well sintered at 540-560 DEG C, and the dielectric constant reaches 11-12, and the quality factor Qf value reaches 71000-75000GHz. The ceramic is less in temperature coefficient of resonance frequency and has an extremely large application value in industry.

Description

technical field [0001] The invention relates to a dielectric ceramic material, in particular to a dielectric resonator, a filter and other microwave components used at microwave frequencies, as well as the dielectric ceramic material of a ceramic capacitor or a temperature compensation capacitor and a preparation method thereof. Background technique [0002] Microwave dielectric ceramics refer to ceramics that are used as dielectric materials in microwave frequency band (mainly UHF, SHF frequency band) circuits and perform one or more functions. They are widely used as resonators, filters, and dielectric substrates in modern communications. Chips, dielectric waveguide circuits and other components are the key basic materials of modern communication technology. They have been used in portable mobile phones, car phones, cordless phones, TV satellite receivers, military radars, etc. It is playing an increasingly important role in the process of miniaturization and integration. ...

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Problems solved by technology

[0010] 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. A large number of exploratory studies have focused on Li-based binary or ternary compounds, and developed such as Li 2 TiO 3 , Li 3 NbO 4 , Li 2 MoO 4 and Li 2 MTi 3 o 8 (M=Mg, Zn) series of microwave dielectric ceramics with good performance, etc., but the system for low-fired microwave dielectric ceramics is still relatively limited, which limits the development of low-temperature co-firing technology and microwave multilayer devices to a large extent. develop

[0011] Considering that there is no literature on lithium-containing compounds Li 2 W 4 o 13 The ceramic preparation and microwave dielectric properties of the research report, our Li 2 W 4 o 13 The sintering characteristics and microwave dielectric properties of the ceramics were studied, and it was found that the ceramics have excellent comprehensive microwave dielectric properties and the sintering temperature is lower than 580 ° C, which can be widely used in microwave devices such as various dielectric substrates, resonators and filters. The manufacturing can meet the technical needs of low temperature co-firing technology and microwave multilayer devices

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