Ultra-low dielectric constant microwave dielectric ceramic li3si2b3o10 and preparation method thereof

Abstract

The invention discloses a temperature-stable ultralow-dielectric-constant microwave dielectric ceramic Li3Si2B3O10 and a preparation method thereof. The preparation method comprises the following steps: (1) weighing and batching the original powder of Li2CO3, SiO2 and H3BO3 which have the purities of over 99.9 percent according to the composition of Li3Si2B3O10; (2) performing wet ball mill and mixing on raw materials in the step (1) for 12 hours, wherein the ball milling medium refers to absolute ethyl alcohol, drying, and presintering in an air atmosphere at the temperature of 750 DEG C for 6 hours; and (3) adding an adhesive into the powder prepared in the step (2), granulating, pressing, forming, and finally sintering in the air atmosphere at the temperature of 800 to 850 DEG C for 4 hours, wherein the adhesive adopts 5 mass percent of polyvinyl alcohol solution, and the addition amount of the polyvinyl alcohol accounts for 3 percent of the total mass of the powder. The ceramic prepared by the invention is good in sintering property, the dielectric constant reaches 5.3 to 5.8, the quality factor Qf value is 113000GHz to 149000GHz, the resonant frequency temperature coefficient is small, and the ceramic has extremely 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

Li 3 Zr 2 B 3 o 10 Ceramic resonant frequency temperature coefficient τ ? Too large (respectively +28ppm / ℃) and cannot be used as a practical microwave dielectric ceramic; while Li 3 Ti 2 B 3 o 10 and Li 3 Ge 2 B 3 o 10 As a semiconductor, its dielectric loss is too large to be used as a microwave dielectric ceramic

Images