阅读说明：本技术 一种中介电常数微波介质陶瓷及其制备方法 (Microwave dielectric ceramic with medium dielectric constant and preparation method thereof ) 是由 付清波 应红 刘光明 杨彬 杨月霞 于 2021-02-18 设计创作，主要内容包括：本发明涉及一种微波介质陶瓷,尤其涉及一种中介电常数微波介质陶瓷及其制备方法。所述中介电常数微波介质陶瓷包括主料和改性添加剂；其中,所述主料为SmAlO-3的组合物和CaTiO-3；所述改性添加剂为选自MnCO-3、Al-2O-3、SiO-2、ZrO-2、Nd-2O-3中的一种或几种。本发明以SmAlO-3的组合物、CaTiO-3为基础,通过掺杂特定的改性添加剂,所得微波介质陶瓷在烧结1500℃后,其介电常数为40～46,Q*f值为40000～50000,全温漂在5ppm/℃以内,热震温差在90℃以上,陶瓷韧性在3.0Mpa·m～(0.5)以上,陶瓷抗弯强度在280MPa以上。(The invention relates to a microwave dielectric ceramic, in particular to a microwave dielectric ceramic with a medium dielectric constant and a preparation method thereof. The medium dielectric constant microwave dielectric ceramic comprises a main material and a modified additive; wherein the main material is SmAlO 3 Composition of (1) and CaTiO 3 (ii) a The modifying additive is selected from MnCO 3 、Al 2 O 3 、SiO 2 、ZrO 2 、Nd 2 O 3 One or more of them. The invention uses SmAlO 3 Composition of (1), CaTiO 3 Based on the microwave dielectric ceramic, the microwave dielectric ceramic obtained by doping specific modified additives has the dielectric constant of 40-46, the Q f value of 40000-50000, the total temperature drift within 5 ppm/DEG C, the thermal shock temperature difference of more than 90 ℃ and the ceramic toughness of 3.0 Mpa.m.C after being sintered at 1500 DEG C 0.5 The bending strength of the ceramic is above 280 MPa.)

1. The microwave dielectric ceramic with medium dielectric constant is characterized by comprising a main material and a modified additive;

wherein the main material is SmAlO₃Composition of (1) and CaTiO₃；

The modifying additive is selected from MnCO₃、Al₂O₃、SiO₂、ZrO₂、Nd₂O₃One or more of them.

2. The medium dielectric constant microwave dielectric ceramic of claim 1 wherein SmAlO is present in a mass ratio₃The composition of (a): CaTiO₃: 30-60% of modified additive: 50-70: 0.5 to 5.

3. A medium dielectric constant microwave dielectric ceramic according to claim 1 or 2, comprising the following components in percentage by mass:

4. a medium dielectric constant microwave dielectric ceramic according to any one of claims 1 to 3 wherein SmAlO is₃The preparation method of the composition comprises the following steps:

mixing Sm₂O₃And Al₂O₃According to a molar ratio of 1: 1 after mixing, Y is added thereto₂O₃、Nb₂O₅、Yb₂O₃And calcining one or more of the raw materials at 900-1100 ℃ for 3-5 hours after ball milling and mixing uniformly.

5. The medium dielectric constant microwave dielectric ceramic according to any one of claims 1 to 3, wherein the CaTiO is₃The preparation method comprises the following steps:

mixing CaCO₃And TiO₂After ball milling and mixing uniformly, calcining for 3-5 h at 1000-1100 ℃;

preferably, the CaCO₃And TiO₂In a molar ratio of 1: 1.

6. a medium dielectric constant microwave dielectric ceramic according to any one of claims 1 to 5 wherein the medium dielectric constant microwave dielectric ceramic has a dielectric constant of 40 to 46.

7. A method for preparing a medium dielectric constant microwave dielectric ceramic as claimed in any one of claims 1 to 6, comprising the steps of:

(1) SmAlO is added₃Composition of (1), CaTiO₃And the modified additive are ball-milled and mixed evenly to obtain slurry;

(2) adding glue into the slurry, uniformly mixing, and then carrying out spray granulation;

(3) and (3) carrying out dry pressing cylindrical molding on the particle mixture subjected to spray granulation, and then carrying out sintering treatment.

8. The method according to claim 7, wherein the sintering treatment is performed at 1300 to 1700 ℃ for 4 to 10 hours.

9. The method of claim 7, wherein the glue is PVA and/or PEG.

10. The method according to claim 7, wherein the inlet temperature of the spray granulation is 180 to 200 ℃ and the outlet temperature is 80 to 100 ℃.

Technical Field

The invention relates to a microwave dielectric ceramic, in particular to a microwave dielectric ceramic with a medium dielectric constant and a preparation method thereof.

Background

Microwave dielectric ceramics refer to ceramic materials which are used as dielectric materials in microwave frequency band circuits and can complete one or more functions. Microwave dielectric ceramics, as a new electronic material, are used as resonators, filters, dielectric substrates, dielectric antennas, dielectric guided wave circuits, etc. in modern communications, and are widely used in many fields of microwave technology, such as mobile phones, car phones, cordless phones, television satellite receivers, satellite broadcasting, radars, radio remote controls, etc. With the continuous development of low-temperature co-fired ceramic technology, the application prospect of the microwave dielectric ceramic material is better.

With the development of 5G technology, the 5G technology has higher requirements on data transmission, capacity, transmission delay and the like. The arrival of 5G leaves the dielectric ceramic material of the existing previous generation communication system to be further improved in microwave performance and ceramic physical performance. At present, the existing microwave material with medium dielectric constant generally has the problems of low Q value, large temperature coefficient, large porcelain brittleness, poor thermal shock performance and the like.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The invention aims to provide a medium-dielectric-constant microwave dielectric ceramic which has higher Q value and excellent ceramic physical property and can solve the problems of low Q value, wide frequency temperature coefficient, poor ceramic physical property and the like of the traditional medium-dielectric-constant microwave dielectric ceramic; the invention also aims to provide a preparation method of the microwave dielectric ceramic with the medium dielectric constant.

Specifically, the invention provides the following technical scheme:

the invention provides a medium dielectric constant microwave dielectric ceramic, which comprises a main material and a modified additive;

wherein the main material is SmAlO₃Composition of (1) and CaTiO₃；

The modifying additive is selected from MnCO₃、Al₂O₃、SiO₂、ZrO₂、Nd₂O₃One or more of them.

The invention discovers that SmAlO is used as a raw material₃Composition of (1) and CaTiO₃Microwave dielectric ceramic with medium dielectric constant as main material,by compounding the specific modified additive, the microwave dielectric ceramic with the medium dielectric constant has better ceramic physical property, and the material has higher Q value and low-temperature-drift microwave property.

Preferably, SmAlO is used in a mass ratio₃The composition of (a): CaTiO₃: 30-60% of modified additive: 50-70: 0.5 to 5.

The invention also discovers that when the main material and the modified additive are compounded under the mass ratio, the obtained microwave dielectric ceramic with the medium dielectric constant has higher Q value and more excellent bending strength, toughness and thermal shock resistance.

In order to further improve the Q value and the physical property of the microwave dielectric ceramic with the medium dielectric constant, the invention optimizes the composition, which is as follows:

preferably, the medium-dielectric-constant microwave dielectric ceramic comprises the following components in percentage by mass:

in addition, the invention also optimizes the preparation method of the two main materials, which comprises the following steps:

preferably, the SmAlO is₃The preparation method of the composition comprises the following steps:

mixing Sm₂O₃And Al₂O₃According to a molar ratio of 1: 1 after mixing, Y is added thereto₂O₃、Nb₂O₅、Yb₂O₃One or more of the raw materials are ball-milled and mixed uniformly, and then calcined at 900-1100 ℃ for 3-5 hours;

preferably, the CaTiO₃The preparation method comprises the following steps:

mixing CaCO₃And TiO₂After ball milling and mixing uniformly, calcining for 3-5 h at 1000-1100 ℃;

further, the CaCO₃And TiO₂In a molar ratio of 1: 1.

in the invention, SmAlO prepared by the method₃Composition of (1) and CaTiO₃The microwave dielectric ceramic is more beneficial to improving various properties of the microwave dielectric ceramic, and particularly has higher Q value and excellent thermal shock property on the premise of keeping medium dielectric constant.

Preferably, the dielectric constant of the medium-dielectric-constant microwave dielectric ceramic is 40-46.

The invention also provides a preparation method of the medium-dielectric-constant microwave dielectric ceramic, which comprises the following steps:

(1) SmAlO is added₃Composition of (1), CaTiO₃And the modified additive are ball-milled and mixed evenly to obtain slurry;

(2) adding glue into the slurry, uniformly mixing, and then carrying out spray granulation;

(3) and (3) carrying out dry pressing cylindrical molding on the particle mixture subjected to spray granulation, and then carrying out sintering treatment.

Preferably, the sintering treatment is carried out at 1300-1700 ℃ for 4-10 h; the cooling rate is controlled within 2 ℃/min, 1000 ℃ tempering and heat preservation are added for 2-4 h, and the phenomenon that the interior of the ceramic is subjected to dark cracking due to the excessively high cooling speed after the ceramic is formed is prevented.

Preferably, the glue is PVA and/or PEG.

Preferably, the inlet temperature of the spray granulation is 180-200 ℃, and the outlet temperature is 80-100 ℃; the spray granulation is carried out under the conditions, a small amount of moisture in the powder can be effectively reserved, the forming pressure is lower during dry pressing, the pressed product is not easy to crack, and the subsequent dry pressing cylinder forming is facilitated.

The invention has the beneficial effects that:

the invention uses SmAlO₃Composition of (1), CaTiO₃Based on the microwave dielectric ceramic, the microwave dielectric ceramic obtained by doping specific modified additives has the dielectric constant of 40-46, the Q f value of 40000-50000, the total temperature drift within 5 ppm/DEG C, the thermal shock temperature difference of more than 90 ℃ and the ceramic toughness of 3.0 Mpa.m.C after being sintered at 1500 DEG C^0.5The bending strength of the ceramic is more than 280 MPa; the medium dielectric constant microwave dielectric of the inventionThe ceramic can replace the existing medium dielectric microwave material, and is better suitable for the future 5G ceramic filter.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The invention provides a preparation method of the medium-dielectric-constant microwave dielectric ceramic, which comprises the following steps:

(1) mixing Sm₂O₃And Al₂O₃According to a molar ratio of 1: 1 after mixing, Y is added thereto₂O₃ 0.05wt％、Yb₂O₃0.25 wt% of the raw materials are ball-milled and mixed uniformly, and then calcined for 3-5 hours at 900-1100 ℃ to prepare SmAlO₃The composition of (1);

(2) according to a molar ratio of 1: 1 taking CaCO₃And TiO₂After ball milling and mixing evenly, calcining for 4 hours at 1050 ℃ to prepare CaTiO₃；

(3) SmAlO is added₃Composition of (1), CaTiO₃And the modified additive are ball-milled and mixed evenly to obtain slurry;

(4) adding PVA (polyvinyl acetate) and PEG (polyethylene glycol) glue into the slurry, uniformly mixing, and then carrying out spray granulation, wherein the inlet temperature of the spray granulation is 180-200 ℃, and the outlet temperature is 80-100 ℃;

(5) and (3) carrying out dry pressing cylindrical molding on the particle mixture subjected to spray granulation, and sintering at 1500 ℃ for 4-10 h.

According to the preparation method, the microwave dielectric ceramic with the medium dielectric constant is provided, and as shown in table 1, comprises the following components in percentage by mass:

TABLE 1

Test example 1

The test example tests the performance of the medium dielectric constant microwave dielectric ceramics of examples 1 to 7 and comparative examples 1 to 3, and specifically includes the following steps:

the test method comprises the following steps: an Agilent network analyzer is adopted to test the microwave performance of the cylinder by using a closed resonant cavity, an oven is used for testing the temperature difference of thermal shock, and a ceramic strength testing device is used for testing the toughness of the ceramic;

the results are shown in Table 2;

TABLE 2

As can be seen from Table 2, the medium dielectric microwave dielectric material with high Q value, low temperature drift and good ceramic physical properties can be obtained by adding a proper amount of modifying additive in a proper proportion of the main components.

Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.