A kind of low dielectric microwave dielectric ceramic material and its ltcc material

A technology of microwave dielectric ceramics and ceramic powders, which is applied in the field of microwave dielectric ceramics, can solve the problems of increased system loss and calorific value, poor system stability, etc. Effect

Active Publication Date: 2020-09-08
HUAZHONG UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

As the operating frequency of communication equipment continues to increase, the signal delay phenomenon will become more obvious, the system loss and heat will also increase, and the system stability will gradually deteriorate

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0042] The invention provides the preparation method of described LTCC microwave dielectric ceramics, comprising the steps of:

[0043] (1) According to the chemical expression Ca 2 RE 8 Si 6 o 26 The stoichiometric ratio of CaCO 3 、Re 2 o 3 and SiO 2 , wherein RE is a rare earth element Nd, Sm or Er, weighed, wet ball milled, dried after ball milled, and then pre-fired to obtain a pre-fired ceramic powder;

[0044] (2) The calcined ceramic powder obtained in step (1) and the sintering aid CaO-La 2 o 3 -B 2 o 3 -SiO 2 The glass is mixed, subjected to wet ball milling again, after drying, adding a binder to granulate, and sintering at a temperature lower than 900°C after tableting to obtain the LTCC microwave dielectric ceramic.

[0045] In some embodiments, the pre-fired temperature in step (1) is 1075°C-1125°C, and the pre-fired time is 3-8 hours. The purpose of the pre-fired is to obtain a pre-fired phase of the ceramic powder.

[0046] In some embodiments, the ...

Embodiment 1~3

[0054] A microwave dielectric ceramic, its preparation method is carried out according to the following steps:

[0055] (1) Analytical pure CaCO 3 , SiO 2 and high purity Nd 2 o 3 、Sm 2 o 3 、Er 2 o 3 After mixing according to the stoichiometric ratio, use zirconium balls as the medium and deionized water as the dispersant, and use a ball mill to mix and stir the powder for 5 hours at a speed of 360r / min; dry the obtained slurry at 1100°C Pre-fired for 5 hours to obtain a pre-fired ceramic powder;

[0056] (2) The pre-fired ceramic powder obtained in step (1) is subjected to wet ball milling again, the dispersant is deionized water, and after drying, 8 wt% polyvinyl alcohol (PVA) binder is added to the dried powder Granulate, and press it into a cylindrical green sample with a thickness to diameter ratio of 0.4 to 0.6 under a pressure of 150MPa; Dielectric ceramic.

[0057] Table 1 Examples 1-3, sintering temperature and microwave dielectric properties

[0058] ...

Embodiment 4 to Embodiment 7

[0061] A kind of LTCC microwave dielectric ceramic material, its preparation method is carried out according to the following steps:

[0062] (1) According to the chemical expression Ca 2 RE 8 Si 6 o 26 The stoichiometric ratio of CaCO 3 、Re 2 o 3 and SiO 2 , wherein RE is the rare earth element Nd, Sm or Er, using zirconium balls as the medium and deionized water as the dispersant, using a ball mill to mix and stir the powder for 5 hours at a speed of 360r / min; the obtained slurry is dried at 1100 Pre-fired at ℃ for 5 hours to obtain pre-fired ceramic powder;

[0063] (2) Add sintering aid to the pre-fired ceramic powder obtained in step (1), and the sintering aid is CaO-La 2 o 3 -B 2 o 3 -SiO 2 For glass, the amount of sintering aid added is 5% or 8% of the mass of the pre-fired ceramic powder, and wet ball milling is carried out. The dispersant uses deionized water, and after drying, 8wt% polyvinyl alcohol (PVA) adhesive Add it to the dry powder for granulation...

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Abstract

The invention belongs to the technical field of microwave dielectric ceramics, and particularly relates to a low-dielectric microwave dielectric ceramic material and an LTCC material thereof. A compound with a chemical general formula of Ca2RE8Si6O26 (wherein RE is selected from the group consisting of Nd, Sm and Er) is used for preparing the microwave dielectric ceramic material, and the LTCC material is further prepared. The ceramic material has a low relative dielectric constant (wherein Epsilon r is in a range of 13.4-14.0), an excellent quality factor (wherein the value of Q*f is in a range of 16300-18600 GHz) and a relatively wide sintering temperature (1350-1400 DEG C); meanwhile, the microwave dielectric ceramic has a negative resonant frequency temperature coefficient (wherein Tauf is no less than -38.1 ppm / DEG C and no more than -17.8 ppm / DEG C). The sintering temperature of the microwave dielectric ceramic material can be reduced to 950 DEG C or below after a certain amountof a sintering aid, namely CaO-La2O3-B2O3-SiO2 glass is added, and the microwave dielectric ceramic can be used as an LTCC material.

Description

technical field [0001] The invention belongs to the technical field of microwave dielectric ceramics, and more specifically relates to a low dielectric microwave dielectric ceramic and an LTCC material thereof. Background technique [0002] Microwave dielectric ceramics refer to ceramic materials used as dielectrics in microwave frequency band (300MHz ~ 30GHz) circuits. As the operating frequency of communication equipment continues to increase, the signal delay phenomenon will become more obvious, the system loss and heat will also increase, and the system stability will gradually deteriorate. The low relative permittivity can reduce the interaction coupling loss between the material and the electrode, and can increase the transmission rate of electrical signals. Therefore, research on microwave dielectric ceramics with low relative permittivity is particularly important. [0003] Low Temperature Co-fired Ceramics (LTCC) technology is a new type of multi-layer substrate t...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/50C04B35/622
CPCC04B35/50C04B35/622C04B2235/3208C04B2235/3418C04B2235/602C04B2235/656C04B2235/6567C04B2235/6583
Inventor 雷文杜康吕文中王晓川汪小红范桂芬付明
Owner HUAZHONG UNIV OF SCI & TECH
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