阅读说明：本技术 一种低烧结温度低介微波介质陶瓷及其制备方法 (low sintering temperature and low dielectric microwave dielectric ceramic and preparation method thereof ) 是由 王丹 吉岸 王晓慧 于 2019-10-12 设计创作，主要内容包括：本发明公开了一种低烧结温度低介微波介质陶瓷,该微波介质陶瓷是由主料和辅料复合而成,主料的组成表达式为(1-x-y)MgSiO<Sub>3</Sub>-xMg<Sub>2</Sub>TiO<Sub>4</Sub>-ySrSiTiO<Sub>5</Sub>,其中,x,y,(1-x-y)均代表摩尔比,x＝0.3,0＜y≤0.035,所述辅料为CuO-ZnO,其中,主料的质量分数为a,辅料的质量分数为b,0≤b≤1％,a+b＝1。本发明还公开了该低烧结温度低介微波介质陶瓷的制备方法。该微波介质陶瓷介电常数低,适用范围广,损耗低,烧结温度较低。(the invention discloses a low-sintering-temperature and low-dielectric microwave dielectric ceramic which is formed by compounding a main material and an auxiliary material, wherein the main material has a composition expression of (1-x-y) MgSiO3-xMg2TiO4-ySrSiTiO5, wherein x, y and (1-x-y) respectively represent a molar ratio, x is 0.3, y is more than 0 and less than or equal to 0.035, and the auxiliary material is CuO-ZnO, wherein the main material has a mass fraction of b, the auxiliary material has a mass fraction of b which is more than or equal to 0 and less than or equal to 1, and a + b is 1. The invention also discloses a preparation method of the low sintering temperature and low dielectric microwave dielectric ceramic. The microwave dielectric ceramic has the advantages of low dielectric constant, wide application range, low loss and low sintering temperature.)

1. A low sintering temperature and low dielectric microwave dielectric ceramic is characterized in that,

The microwave dielectric ceramic is formed by compounding a main material and an auxiliary material, wherein the main material has a composition expression of (1-x-y) MgSiO3-xMg2TiO4-ySrSiTiO5, wherein x, y and (1-x-y) all represent molar ratios, x is 0.3, y is more than 0 and less than or equal to 0.035, and the auxiliary material is CuO-ZnO, wherein the mass fraction of the main material is a, the mass fraction of the auxiliary material is b, b is more than or equal to 0 and less than or equal to 1 percent, and a + b is 1.

2. the low sintering temperature and low dielectric microwave dielectric ceramic of claim 1, wherein the CuO-ZnO adjuvant is prepared by CuO and ZnO according to a molar ratio of 1: 1.

3. A preparation method of low sintering temperature and low dielectric microwave dielectric ceramic is characterized by comprising the following steps:

(1) preparing the main materials of the microwave dielectric ceramic: firstly, mixing MgO, SiO2, TiO2 and SrCO3 according to the molar ratio of corresponding elements in a composition expression (1-x-y) MgSiO3-xMg2TiO4-ySrSiTiO5, mixing MgO, SiO2, TiO2 and SrCO3, fully ball-milling, drying and sieving after ball-milling, and then putting into a corundum crucible for roasting to obtain a main material, wherein in the composition expression (1-x-y) MgSiO3-xMg2TiO4-ySrSiTiO5, x, y and (1-x-y) represent the molar ratio, x is 0.3, and y is more than 0 and less than or equal to 0.035;

(2) preparing low sintering temperature and low dielectric microwave dielectric ceramic: respectively weighing CuO-ZnO auxiliary materials and the main materials prepared in the step (1) according to the mass percentage, mixing the main materials and the auxiliary materials, then fully ball-milling, drying, granulating and sieving, pressing and molding the sieved mixed powder, and finally sintering to obtain the low-dielectric microwave dielectric ceramic; the mass fraction of the main material is a, the mass fraction of the auxiliary material is b, b is more than or equal to 0 and less than or equal to 1 percent, and a + b is 1.

4. The preparation method of the low sintering temperature and low dielectric microwave dielectric ceramic as claimed in claim 3, wherein the roasting process in the step (1) is roasting and heat preservation at 950-1050 ℃ for 3-5 h.

5. the preparation method of the low sintering temperature and low dielectric microwave dielectric ceramic as claimed in claim 3, wherein the preparation process of the CuO-ZnO auxiliary material is as follows: and fully mixing ZnO and CuO, then ball-milling, drying and sieving after ball-milling, and then putting into a corundum crucible for roasting to obtain the CuO-ZnO auxiliary material.

6. The method for preparing a low sintering temperature and low dielectric microwave dielectric ceramic as claimed in claim 5, wherein when preparing the CuO-ZnO auxiliary material, the molar ratio of CuO to ZnO is 1: 1.

7. the preparation method of the low sintering temperature and low dielectric microwave dielectric ceramic as claimed in claim 5, wherein the roasting process for preparing the CuO-ZnO auxiliary material is roasting and heat preservation at 600-650 ℃ for 3-5 h.

8. A method as claimed in claim 3, wherein in step (2), the sieved particles are pressed into cylinders with a diameter of 10mm and a height of 6 mm.

9. the method for preparing a low sintering temperature and low dielectric microwave dielectric ceramic as claimed in claim 3, wherein the sintering process in the step (2) is sintering at 1100-1250 ℃ for 4 hours.

10. the method for preparing a low sintering temperature and low dielectric microwave dielectric ceramic as claimed in claim 3, wherein the sintering process in step (2) is sintering at 1100-1200 ℃ for 4 hours.

Technical Field

The invention belongs to the technical field of electronic ceramics and preparation thereof, and particularly relates to a low-sintering temperature and low-dielectric microwave dielectric ceramic and a preparation method thereof.

Background

Microwave dielectric ceramics, as a novel electronic material, are used as resonators, filters, dielectric substrates, dielectric antennas, dielectric guided-wave loops and the like in modern communications, and are widely applied to many fields of microwave technology, such as mobile communications, satellite communications, military radars and the like. With the development of scientific technology, the amount of communication information is rapidly increasing, and the requirements of people for wireless communication, the use of microwave communication systems such as satellite communication and satellite direct broadcast television becomes a necessary trend for the development of current communication technology, which gradually increases the civil requirements of microwave materials, such as mobile communication devices such as mobile phones, car phones, cellular cordless phones, and the like, and new application devices such as satellite direct broadcast television, and the like.

ceramics with different dielectric constants will vary in application. The dielectric ceramic with the dielectric constant of 20-40 has low dielectric loss under high frequency, and is mainly used as a resonator, a filter and the like in the fields of mobile communication base stations, satellite communication and the like. Dielectric ceramics with dielectric constant less than 10, such as Al2O3, are generally used as substrate materials, electronic product packaging materials and the like, and mainly such materials can meet certain insulating performance and can shorten the delay time of signals.

Al2O3 has excellent performance and good chemical stability, but the sintering temperature is high, and the sintering is difficult to form porcelain. Therefore, the ceramic material with low sintering temperature, low dielectric constant and excellent microwave dielectric property is obtained by taking MgSiO3 as a base material and adopting a multi-phase compounding and additive mode.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a low sintering temperature and low dielectric microwave dielectric ceramic and a preparation method thereof; the microwave dielectric ceramic has the advantages of low dielectric constant, wide application range, low loss and low sintering temperature.

In order to achieve the technical purpose and achieve the technical effect, the invention is realized by the following technical scheme:

The low-sintering-temperature low-dielectric microwave dielectric ceramic is formed by compounding a main material and an auxiliary material, wherein the main material has a composition expression of (1-x-y) MgSiO3-xMg2TiO4-ySrSiTiO5, wherein x, y and (1-x-y) represent molar ratios, x is 0.3, y is more than 0 and less than or equal to 0.035, and the auxiliary material is CuO-ZnO, wherein the mass fraction of the main material is a, the mass fraction of the auxiliary material is b, more than or equal to 0 and less than or equal to 1, and a + b is 1.

in the technical scheme, the CuO-ZnO auxiliary material is prepared from CuO and ZnO according to the molar ratio of 1: 1.

the invention also provides a preparation method of the low sintering temperature and low dielectric microwave dielectric ceramic, which comprises the following steps:

(1) Preparing the main materials of the microwave dielectric ceramic: firstly, mixing MgO, SiO2, TiO2 and SrCO3 according to the molar ratio of corresponding elements in a composition expression (1-x-y) MgSiO3-xMg2TiO4-ySrSiTiO5, mixing MgO, SiO2, TiO2 and SrCO3, fully ball-milling, drying and sieving after ball-milling, and then putting into a corundum crucible for roasting to obtain a main material, wherein in the composition expression (1-x-y) MgSiO3-xMg2TiO4-ySrSiTiO5, x, y and (1-x-y) represent the molar ratio, x is 0.3, and y is more than 0 and less than or equal to 0.035;

(2) Preparing low sintering temperature and low dielectric microwave dielectric ceramic: respectively weighing CuO-ZnO auxiliary materials and the main materials prepared in the step (1) according to the mass percentage, mixing the main materials and the auxiliary materials, then fully ball-milling, drying, granulating and sieving, pressing and molding the sieved mixed powder, and finally sintering to obtain the low-dielectric microwave dielectric ceramic; the mass fraction of the main material is a, the mass fraction of the auxiliary material is b, b is more than or equal to 0 and less than or equal to 1 percent, and a + b is 1.

Preferably, the roasting process in the step (1) is roasting and heat preservation at 950-1050 ℃ for 3-5 h.

In the preparation method, the preparation process of the CuO-ZnO auxiliary material comprises the following steps: and fully mixing ZnO and CuO, then ball-milling, drying and sieving after ball-milling, and then putting into a corundum crucible for roasting to obtain the CuO-ZnO auxiliary material.

wherein, when preparing the auxiliary CuO-ZnO material, the mol ratio of CuO and ZnO is 1: 1.

preferably, the roasting process for preparing the auxiliary CuO-ZnO material is roasting at 600-650 ℃ and keeping the temperature for 3-5 h.

Preferably, in step (2), the sieved granules are compressed into cylinders with a diameter of 10mm and a height of 6 mm.

preferably, the sintering process in the step (2) is sintering at 1100-1250 ℃ for 4 hours.

More preferably, the sintering process in the step (2) is sintering at 1100-1200 ℃ for 4 hours.

compared with the prior art, the invention has the following beneficial effects: in the microwave dielectric ceramic provided by the invention, a Ti source and a Sr source are introduced into MgSiO3 to form a MgSiO3-Mg2TiO4-SrSiTiO5 composite phase, so that the sintering temperature can be reduced and the temperature stability can be improved. The introduction of SrSiTiO5 can improve the sinterability of the ceramic material and reduce the sintering temperature of the ceramic material; however, SrSiTiO5 can reduce the sintering temperature range of the ceramic, which is about 1250-1260 ℃, that is, when the temperature is lower than 1250 ℃, the material cannot form compact ceramic, and the loss is large, but when the temperature is higher than 1260 ℃, the ceramic can deform due to overburning, which is not beneficial to practical production application, so that a CuO-ZnO sintering aid with a certain proportion is added, so that the ceramic can be densely sintered at a lower temperature, the loss is reduced, and the microwave dielectric property is improved.

In addition, the invention can obtain the low dielectric ceramic material with dielectric constant of about 9.5, low loss and nearly zero temperature coefficient of resonance frequency by designing the introduction of each component and adjusting the proportion of each component.

The relative dielectric constant of the microwave dielectric ceramic is 9-10, the microwave performance Qf is 41000-84000GHz, the temperature coefficient of the resonant frequency is-12.7 ppm/DEG C to-1.5 ppm/DEG C, and the sintering temperature can be as low as 1100-1200 ℃.

Detailed Description

The following detailed description of the preferred embodiments of the present invention is provided to enable those skilled in the art to more readily understand the advantages and features of the present invention, and to clearly and unequivocally define the scope of the present invention.

The low-sintering-temperature low-dielectric microwave dielectric ceramic is formed by compounding a main material and an auxiliary material, wherein the main material has a composition expression of (1-x-y) MgSiO3-xMg2TiO4-ySrSiTiO5, wherein x, y and (1-x-y) represent a molar ratio, x is 0.3, y is more than 0 and less than or equal to 0.035, and the auxiliary material is CuO-ZnO, wherein the main material has a mass fraction a, the auxiliary material has a mass fraction b, more than or equal to 0 and less than or equal to 1, and a + b is 1.

In the technical scheme, the CuO-ZnO in the auxiliary materials is prepared from CuO and ZnO according to the molar ratio of 1: 1.

The invention also provides a preparation method of the low sintering temperature and low dielectric microwave dielectric ceramic, which comprises the following steps:

Step one, preparing a main material of the microwave dielectric ceramic: firstly, mixing MgO, SiO2, TiO2 and SrCO3 according to the molar ratio of corresponding elements in a composition expression (1-x-y) MgSiO3-xMg2TiO4-ySrSiTiO5, mixing MgO, SiO2, TiO2 and SrCO3, fully ball-milling, drying and sieving after ball-milling, and then putting into a corundum crucible for roasting to obtain a main material, wherein in the composition expression (1-x-y) MgSiO3-xMg2TiO4-ySrSiTiO5, x, y and (1-x-y) represent the molar ratio, x is 0.3, and y is more than 0 and less than or equal to 0.035;

step two, preparing the auxiliary material of the microwave dielectric ceramic: fully mixing ZnO and CuO, then ball-milling, drying and sieving after ball-milling, and then putting into a corundum crucible for roasting to obtain a CuO-ZnO auxiliary material;

Step three, preparing the low sintering temperature and low dielectric microwave dielectric ceramic: respectively weighing the main material prepared in the step one and the auxiliary material prepared in the step two according to the mass percentage, mixing the main material and the auxiliary material, then fully ball-milling, drying, granulating and sieving, pressing and molding the sieved mixed powder, and finally sintering to obtain the low dielectric microwave dielectric ceramic; the mass fraction of the main material is a, the mass fraction of the auxiliary material is b, b is more than or equal to 0 and less than or equal to 1 percent, and a + b is 1.

Wherein, the roasting process in the first step is roasting and heat preservation for 3-5 hours at 950-1050 ℃.

In the preparation method, the molar ratio of CuO to ZnO in the second step is 1: 1.

Wherein, the roasting process in the second step is roasting and heat preservation for 3-5 hours at the temperature of 600-650 ℃.

In the third step, the sieved particles are pressed into cylinders with the diameter of 10mm and the height of 6 mm.

Wherein, the sintering process in the third step is sintering at 1100-1250 ℃ for 4 hours.

the following examples further illustrate the invention but are not intended to limit the invention thereto.