Low-temperature sinterable microwave dielectric ceramic li2zn3wo7 and its preparation method

Abstract

The invention discloses a low temperature sinterable microwave dielectric ceramic Li2Zn3WO7 and a preparation method thereof. The method includes: (1) conducting weighing and burdening on the original powder of Li2CO3, ZnO and WO3 with purity of more than 99.9% according to the composition of Li2Zn3WO7; (2) subjecting the raw materials obtained in step (1) to wet ball-milling mixing for 12h, taking distilled water as a milling medium, performing drying and then conducting presintering in a 700DEG C atmosphere for 6h; and (3) adding a binder into the powder prepared in step (2) and performing granulation, then conducting compression moulding, and finally carrying out sintering in a 750-780DEG C atmosphere for 4h. The binder is a polyvinyl alcohol solution with a mass concentration of 5%, and the adding amount of polyvinyl alcohol accounts for 3% of the total mass of the powder. The ceramic prepared by the invention can well sinter at 750-780DEG C, has a dielectric constant up to 15-16, a quality factor Qf value up to 69000-81000GHz, and a small temperature coefficient of resonant frequency, thus having substantial application value in industry.

Description

technical field [0001] The invention relates to a dielectric ceramic material, in particular to a microwave component such as a dielectric substrate used at a microwave frequency, a 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 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 miniaturizat...

AI Technical Summary

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 2 MoO 4 and Li 2 MTi 3 o 8 (M=Mg or Zn) series of microwave dielectric ceramics with good performance, etc., but the microwave dielectric ceramic system that can be fired at low temperature is still relatively limited, and the τ of single-phase microwave dielectric ceramics with low inherent sintering temperature ? Usually large, can not meet the requirements of device thermal stability, which largely limits the development of low temperature co-firing technology and microwave multilayer devices

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