Multiphase rock-salt structure ultra-low loss microwave dielectric ceramic material and preparation method thereof

Abstract

The invention provides a multi-phase rock-salt structure ultra-low loss microwave dielectric ceramic material and a preparation method thereof, the general formula of which is Li 3+ a Mg 2‑b / 3 x 1‑2b / 3 Y b+c o 6+2c · dZ, X is Nb 5+ or Ta 5+ , Y is Ti 4+ , Sn 4+ or Zr 4+ , Z is ZnO or LiF, 0.03≤a≤0.12, 0.12≤b≤0.38, 0≤c≤0.15, 0wt%≤d≤5wt%, the preparation method is according to the general formula ingredients, after the first ball mill mixing, drying, Screening, pre-calcination, and second ball milling, drying, granulation, debinding, and sintering in air; the crystal phase of the finished product is an ordered orthorhombic phase rock salt structure and a disordered cubic phase rock salt The composite phase of the structure; the microwave dielectric ceramic material provided by the present invention shows excellent performance under the condition of two different rock salt structural components adjustable: its relative permittivity ε r Adjustable between 8.8~17.9, Q×f value is 82000GHz~128000GHz, resonant frequency temperature coefficient τ f It can be adjusted between -33ppm / ℃~+11ppm / ℃, the preparation process is simple, and the performance is stable, which meets the application requirements of modern microwave devices.

Description

technical field [0001] The invention belongs to the technical field of electronic information functional materials and devices, and in particular relates to an ultra-low loss microwave dielectric ceramic material with an adjustable frequency temperature coefficient near zero end and a preparation method thereof. Background technique [0002] Microwave dielectric ceramics are key materials for microwave components such as resonators, filters, and dielectric substrates used in modern mobile communications, satellite communications, and military radars. As early as 2009, the State Council put forward the importance of developing dielectric ceramics with serialized dielectric constant and excellent microwave dielectric properties in the document "Outline of Electronic Information Industry Adjustment and Revitalization Plan" in 2009. High frequency is an inevitable trend in the development of digital products. With the continuous development of electronic information technology t...

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Problems solved by technology

Although Li 3 Mg 2 NbO 6 Microwave dielectric ceramics have lower losses, but have the same defects as most pristine microwave ceramics

First, in a high-temperature sintering environment around 1300 °C, Li + The severe volatilization of ions leads to Li 3 Mg 2 NbO 6 There are more pores in the structure, which increases the dielectric loss of the material; second, the large negative frequency temperature coefficient makes Li 3 Mg 2 NbO 6 Raw ceramic materials are difficult to meet industrial applications; third, higher firing temperatures increase the cost of industrial production

Sintering the material in an atmosphere rich in Li volatiles or calcining in a closed space to suppress the volatilization of lithium are two commonly used methods. The former is often complex in process, and the latter generally uses platinum crucibles or buried sintered powders that do not react with raw materials. However, due to the high price of platinum and the complicated burying process, it is difficult to apply it in actual industrial production.

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