Low-temperature sintered composite microwave dielectric ceramic material and preparation method thereof

Abstract

The invention discloses a low-temperature sintered medium-dielectricconstant high-quality-factor microwave dielectric ceramic material and a preparation method thereof. The low-temperature sintered composite microwave dielectric ceramic material is composed of an Li2O-Nb2O5-TiO2 material and a composite burning reducer which accounts for 1-10 wt% of the main crystal phase. The low-temperature sintered composite microwave dielectric ceramic material is obtained by solid-phase reaction. The composition of the Li2O-Nb2O5-TiO2 material is LiaNbbTicO3, wherein 2<a<2.2, 0.2<b<0.3, and 0.6<c<0.7. The composite burning reducer is prepared from the following raw materials: lithium carbonate (Li2CO3), zinc oxide (ZnO), aluminum oxide (Al2O3), calcium oxide (CaO), silicon dioxide (SiO2), boron trioxide (B2O3) and trace amounts of additive components. The low-temperature sintered LTCC (low temperature co-fired ceramic) microwave dielectric ceramic disclosed by the invention has the advantages of good sintering property at 850-900 DEG C, the medium dielectric constant (Epsilonr is 18-24), high quality factor Qf and low temperature coefficient of resonance frequency, can be used for manufacturing a LTCC system, multilayered medium resonator, microwave antenna, filter or any other microwave device, and has great industrial application value.

Description

technical field [0001] The invention belongs to the field of dielectric ceramics, in particular to composite microwave dielectric ceramic materials. 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. Chips, dielectric waveguide circuits and other components are the key basic materials of modern communication technology. They have very important applications in portable mobile phones, TV satellite receivers, and military radars. In the process of miniaturization and integration of modern communication tools Zhongzheng is playing an increasingly important role. [0003] Dielectric ceramics used in the microwave frequency band should meet the requirements: (1) appropriate dielectric constant to facilitate the mini...

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Problems solved by technology

However, the sintering temperature of undoped LNT ceramics is relatively high (1150°C), and it cannot be directly co-fired with low melting point metals such as Ag and Cu.

In order to reduce the sintering temperature, one of the traditional methods is to add low melting point oxides, such as B 2 o 3 and V 2 o 5 , while the free B 2 o 3 and V 2 o 5 In the late casting process, the viscosity of the slurry is too high and unstable, which limits its practical application; another method is to add low-melting glass, but the existence of the glass phase greatly increases the dielectric loss of the material, and the glass is in Unstable performance and high cost during the smelting process greatly limit the development of LNT materials and microwave multilayer devices

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