Microwave dielectric ceramic with layered structure and preparation method thereof

Abstract

The invention relates to a microwave dielectric ceramic with a layered structure and a preparation method thereof. The method comprises S1, combining BaTi 4 o 9 and Zn 1.01 Nb 2 o 6 placed in a ball mill, the BaTi 4 o 9 and Zn 1.01 Nb 2 o 6 Ball milled into BaTi 4 o 9 Powder and Zn 1.01 Nb 2 o 6 powder to make BaTi 4 o 9 Powder and Zn 1.01 Nb 2 o 6 The particle size of the powder is the preset particle size; S2, the BaTi 4 o 9 Powder and Zn 1.01 Nb 2 o 6 Powder according to BaTi 4 o 9 -Zn 1.01 Nb 2 o 6 Weigh the chemical composition; S3, 50% of the BaTi in the S2 step 4 o 9 The powder is placed in the mold, and the first substrate is prepared by dry pressing; S4, placing Zn on the first substrate 1.01 Nb 2 o 6 Powder, the second substrate is prepared by dry pressing; S5, placing the remaining 50% of the BaTi in the S2 step on the second substrate 4 o 9 powder, and prepare a green body with a heterogeneous layered structure by dry pressing; S6, debinding and sintering the green body prepared in steps S3 to S5 to prepare a microwave dielectric ceramic; the heterogeneous layered structure microwave prepared by the present invention Dielectric ceramics can avoid local uneven distribution of trace additives in the parent material and mixing of impurities, and improve the stability and quality factor of ceramic production.

Description

technical field [0001] The invention relates to the technical field of microwave dielectric ceramics, in particular to a layered microwave dielectric ceramic and a preparation method thereof. Background technique [0002] Microwave Dielectric Ceramics (MWDC for short) are used in microwave frequency band (300MHz ~ 300GHz) circuits as dielectric materials and ceramics that perform one or more functions. They are widely used in modern communications as resonators, filters, Components such as dielectric antennas 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. The process of miniaturization and integration of tools is playing an increasingly important role. [0003] Since the 1970s, a large-scale development of dielectric ceramic materials has begun. Dielectric ceramics used in microwave frequency bands usually...

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Problems solved by technology

[0004] Among them, BaTi 4 o 9 Microwave-based dielectric ceramics have been widely used in many fields due to their low cost of raw materials, excellent microwave dielectric properties including suitable dielectric constant (38) and high quality factor (38000, @4GHz). However, BaTi 4 o 9 The resonant frequency temperature coefficient (+14ppm / ℃) of microwave-based dielectric ceramics is difficult to meet the requirements of filters and resonators (<±3ppm / ℃). Therefore, it is necessary to do research on its modification to ensure high dielectric constant and High quality factor, through the introduction of additives to reduce its resonant frequency temperature coefficient

[0005] The traditional preparation method is to add additives and BaTiO 4 The powders are mixed and ground together, and then dried, granulated, shaped and sintered to obtain ceramic products. Due to the additives and BaTi 4 o 9 The density is not the same, so that with BaTi 4 o 9 When the powder is mixed, it is easy to have local uneven distribution, which leads to the generation of impurities during the ceramic sintering process, which reduces the quality factor and causes large fluctuations in ceramic performance, making it difficult to meet the stability of production.

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