Low-temperature sintered tungstate microwave dielectric ceramic Li2MW2O8 and preparation method thereof

Abstract

The invention discloses a low-temperature sintered tungstate microwave dielectric ceramic Li2MW2O8 and a preparation method thereof. The low-temperature sintered tungstate microwave dielectric ceramic is made of a material with the component of Li2MW2O8, wherein M is selected from one of Zn, Mg and Cu. The preparation method of the low-temperature sintered tungstate microwave dielectric ceramic Li2MW2O8 comprises the following steps of: (1) weighting and proportioning initial Li2CO3, MO and WO3 powders with the purities of over 99.9% according to the chemical formula Li2MW2O8, wherein M is selected from one of Zn, Mg and Cu; (2) performing wet-type ball milling and mixing on the raw materials for 12 hours, drying the raw materials, and then, presintering the raw materials at 600-DEG C atmosphere for 6 hours, wherein distilled water is used as a solvent; and (3) adding a binder into the prepared powder, pelleting, then, carrying out compression moulding, and finally, sintering at 650-700 DEG C atmosphere for 4 hours, wherein the binder is a 5wt% polyvinyl alcohol solution and accounts for 3% of the total quantity of the powder. The ceramic prepared by the invention is good in sintering at the temperature of 650-700 DEG C, high dielectric constant up to 22-24, high quality factor (Qf) value up to 67000-86000GHz and small temperature coefficient of resonance frequency.

Description

technical field [0001] The invention relates to a dielectric ceramic material, in particular to a microwave dielectric ceramic material for microwave components used at microwave frequencies, such as a dielectric substrate, a resonator, and a filter, 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. 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. ...

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 3 NbO 4 , 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, which limits the development of low temperature co-firing technology and microwave multilayer devices to a large extent.

Images