Ultra-low dielectric constant microwave dielectric ceramic inalzn 5 o 8 and its preparation method

Abstract

The invention discloses a temperature stabilized microwave dielectric ceramic InAlZn5O8 with an ultralow dielectric constant and a preparation method thereof. The preparation method includes the following steps: (1) weighing and batching original powder of In2O3, Al2O3 and ZnO with the purity of 99.9% (weight percentage) above according to the composition of InAlZn5O8; (2) wet type balling-milling and mixing the raw materials in step (1) for 12 hours, taking distilled water as the ball-milling medium, drying the mixture and pre-burning the mixture for 6 hours at the atmosphere of 1200 DEG C; (3), adding a binder in the powder prepared in the step (2) and pelleting, pressing and forming, and finally sintering the product for 4 hours at the atmosphere of 1250-1300 DEG C, wherein the binder is polyvinyl alcohol solution with the mass concentration of 5%, the additive amount of the polyvinyl alcohol is 3% of the total mass of the powder. The prepared ceramic is well sintered, has the dielectric constant reaching 7.1-7.7, the Qf (quality factor) value reaching 145000-191000 GHz, is low in temperature coefficient of resonance frequency, and has great application value in the 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 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] Due to the three performance indicators of microwave dielectric ceramics (ε r with Q f and τ ƒ ) 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 resonant frequency temperature coefficient and quality factor, explore and develop near-zero resonant frequency temperature coefficient (-10 ppm / ℃≤τ ƒ ≤+10ppm / ℃) and a series of microwave dielectric ceramics with higher quality factors and different dielectric constants are difficult problems 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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