High-quality-factor temperature-stable microwave dielectric ceramic Li2SrZnGeO5 with ultralow dielectric constant
A technology of microwave dielectric ceramics and ultra-low dielectric constant, applied in the field of dielectric ceramic materials, can solve the problems of no resonance peak, low quality factor, excessive temperature coefficient of resonance frequency, etc., and achieve small temperature coefficient τf and stable temperature Good performance, meet the technical needs of the effect
Inactive Publication Date: 2016-12-07
GUILIN UNIVERSITY OF TECHNOLOGY
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Problems solved by technology
[0009] In the process of exploring and developing new low-firing microwave dielectric ceramic materials, material systems such as Li-based compounds, Bi-based compounds, tungstate 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 f ) is a mutual 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 practical application requirements.
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
Exploration and development can not only sinter at low temperature but also have near-zero resonance frequency temperature coefficient (-10ppm / ℃≤τ f ≤+10ppm / °C) 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
Our pair group becomes Li 2 SrZnGeO 5 , Li 2 CaO 5 The sintering and microwave dielectric properties of the ceramics were studied, and it was found that their sintering temperature was lower than 1250 ° C, where Li 2 SrZnGeO 5 With near-zero resonant frequency temperature coefficient and high quality factor, Li 2 CaO 5 Ceramics are semiconductors, which have large dielectric loss and no resonance peak in the microwave frequency range, so they cannot be used as practical microwave dielectric ceramics
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[0018] Table 1 shows three specific examples of different sintering temperatures constituting the present invention and their microwave dielectric properties. The preparation method is as above, and the microwave dielectric performance is evaluated by the cylindrical dielectric resonator method.
[0019] The ceramics can be widely used in the manufacture of microwave devices such as various dielectric substrates, resonators and filters, and can meet the technical needs of mobile communication and satellite communication systems.
[0020] Table 1:
[0021]
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Abstract
The invention discloses high-quality-factor temperature-stable microwave dielectric ceramic Li2SrZnGeO5 with ultralow dielectric constant with a preparation method thereof. The preparation method includes: (1), weighing and burdening raw powders of Li2CO3, SrCO3, ZnO and GeO2 having a purity of 99.9% and above (in percent by weight) according to composition of Li2SrZnGeO5; (2), wet ball-milling and mixing the material of step (1) for 12 hours by using distilled water as a ball milling medium, drying, and pre-sintering in atmosphere at 1150 DEG C for 6 hours; (3), adding a binder to the powder of step (2), granulating, press-forming, and sintering in atmosphere at 1200 to 1250 DEG C for 4 hours, wherein the binder is polyvinyl alcohol solution having a mass concentration of 5%, and the polyvinyl alcohol that is added accounts for 3% of the total mass of the powder. The ceramic prepared herein is well sinterable at 1250 DEG C and below, up to 17.9 to 18.8 in dielectric constant, up to 85000 to 114000 GHz in quality factor Qf and low in resonant frequency temperature coefficient and is highly worthy of application 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...
Claims
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IPC IPC(8): C04B35/01C04B35/622C04B35/626
CPCC04B35/01C04B35/622C04B35/62615C04B2235/3284C04B2235/3287C04B2235/442C04B2235/96
Inventor校凯段炼苏和平
OwnerGUILIN UNIVERSITY OF TECHNOLOGY