Low-loss temperature-stable low-dielectric constant microwave dielectric ceramic SrLi3Sm3W2O13

Abstract

The invention discloses low-loss temperature-stable low-dielectric constant microwave dielectric ceramic SrLi3Sm3W2O13 and a preparation method thereof. The preparation method comprises the following steps: (1) weighing original powder of SrCO3, Li2CO3, Sm2O3 and WO3 according to the composition of SrLi3Sm3W2O13 for compounding, wherein the purities are 99.9 percent or higher by weight percent; (2) conducting wet ball mill mixing on the raw materials obtained in the step (1) for 12 hours, carrying out drying, and pre-burning the dried mixture in a 720 DEG C air atmosphere for 6 hours, wherein distilled water is taken as a ball mill medium; (3) adding a binder into the powder obtained in the step (2), carrying out pelleting and pressure molding, and sintering in a 770 to 820 DEG C air atmosphere for 4 hours, wherein the binder adopts a polyvinyl alcohol solution of which the mass concentration is 5 percent, and the add amount of the polyvinyl alcohol solution is 3 percent of the total weight of the powder. The microwave dielectric ceramic prepared according to the preparation method can be well sintered at 820 DEG C or a lower temperature, reaches 25.3 to 26.4 in dielectric constant and 91000 to 131000 GHz in quality factor Qf, is low in temperature coefficient of resonance frequency, and has a very high 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] In the process of exploring and developing new low-fire microwave dielectric ceramic materials, material systems such as Li-based compounds, Bi-based compounds, molybdate-based 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 ? ) 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 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 requirements of practical applications.

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

Explore and develop low-temperature sintering and near-zero resonant frequency temperature coefficient (-10 ppm / ℃≤τ ? ≤+10 ppm / ℃) 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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