阅读说明：本技术 复合介质陶瓷及其制备方法和微波滤波器 (Composite dielectric ceramic, preparation method thereof and microwave filter ) 是由 冒旭 于 2021-09-03 设计创作，主要内容包括：本申请公开了一种复合介质陶瓷及其制备方法和微波滤波器。本申请复合介质陶瓷包括介质陶瓷本体,在介质陶瓷本体的表面结合有Ag层,且由介质陶瓷本体至Ag层外表面的方向,Ag层的密度呈梯度增加。本申请微波滤波器为本申请复合介质陶瓷。本申请复合介质陶瓷和微波滤波器所含Ag层与介质陶瓷本体之间应力小,结合强度高,具有低损耗特性,且成本低。本申请复合介质陶瓷的制备方法能有效保证了制备的复合介质陶瓷结构和低损耗以及电磁等性能稳定。(The application discloses a composite dielectric ceramic, a preparation method thereof and a microwave filter. The composite dielectric ceramic comprises a dielectric ceramic body, wherein an Ag layer is combined on the surface of the dielectric ceramic body, and the density of the Ag layer is increased in a gradient manner from the dielectric ceramic body to the direction of the outer surface of the Ag layer. The microwave filter is the composite dielectric ceramic. The composite dielectric ceramic and the microwave filter have the advantages of small stress between the Ag layer and the dielectric ceramic body, high bonding strength, low loss and low cost. The preparation method of the composite dielectric ceramic can effectively ensure that the prepared composite dielectric ceramic has stable properties such as structure, low loss, electromagnetism and the like.)

1. A composite dielectric ceramic comprises a dielectric ceramic body, and is characterized in that: an Ag layer is combined on the surface of the dielectric ceramic body, and the density of the Ag layer is increased in a gradient manner from the dielectric ceramic body to the outer surface of the Ag layer.

2. The composite dielectric ceramic of claim 1, wherein: the density range of the Ag layer is 7.5-10.1 g/cm³(ii) a And/or

The thickness of the Ag layer is 3-6 mu m.

3. The composite dielectric ceramic of claim 1 or 2, wherein: the dielectric ceramic body is a microwave dielectric ceramic body.

4. The preparation method of the composite dielectric ceramic is characterized by comprising the following steps of:

providing a dielectric ceramic body;

and forming an Ag layer on the surface of the dielectric ceramic body, wherein the density of the Ag layer is increased in a gradient manner from the dielectric ceramic body to the outer surface of the Ag layer.

5. The method of claim 4, wherein: the method for forming the Ag layer on the surface of the dielectric ceramic body comprises the following steps:

depositing an Ag target on the surface of the dielectric ceramic body by adopting a magnetron sputtering method to form an Ag layer; wherein the magnetron sputtering pressure in the magnetron sputtering is gradually reduced along with the progress of the magnetron sputtering.

6. The method of claim 5, wherein: the magnetron sputtering pressure is 8.0 Pa-0.2 Pa, and the sputtering time is 20-30 min.

7. The production method according to claim 5 or 6, characterized in that: the direct current voltage of the magnetron sputtering is 2000-3000V, and the current is 0.5-2.0A; and/or

In the magnetron sputtering, the temperature of the dielectric ceramic body is 80-160 ℃; and/or

The vacuum degree of the back bottom in the magnetron sputtering is 5 multiplied by 10^-4Pa～1×10^-3Pa; and/or

The argon flow in the magnetron sputtering is 20sccm to 50 sccm.

8. The production method according to any one of claims 4 to 6, characterized in that: before the step of forming the Ag layer on the surface of the dielectric ceramic body, the method also comprises the following steps of pretreating the dielectric ceramic body:

firstly, grinding and cleaning the dielectric ceramic body, and then drying.

9. A microwave filter, characterized by: the composite dielectric ceramic is the composite dielectric ceramic of any one of claims 1 to 3 or the composite dielectric ceramic prepared by the preparation method of any one of claims 4 to 8, and the dielectric ceramic body contained in the composite dielectric ceramic is a microwave dielectric ceramic body.

10. A microwave filter according to claim 9, wherein: the bonding force between the Ag layer and the microwave dielectric ceramic body reaches 38.2N/mm²(ii) a And/or

The insertion loss of the microwave filter is <1 dB.

Technical Field

The application belongs to the technical field of electronic materials, and particularly relates to a composite dielectric ceramic, a preparation method thereof and a microwave filter.

Background

With the rapid development of 5G technology, there is an increasing demand for miniaturization, weight reduction, and multi-functionalization of electronic devices. In the fields of the internet of things, satellite communication, wearable equipment, electronic medical equipment and the like, higher requirements are put forward on the performance and reliability of microwave devices. The microwave filter is a key device for processing signals when transmitting and receiving signals in the current communication base station, and the performance improvement determines the improvement of communication quality and the development direction of communication technology.

At present, with the improvement of communication frequency, the miniaturization of the filter is one of the key technologies for the development of the base station, and the high-performance microwave dielectric ceramic is a key material for realizing the miniaturization of the filter. In the preparation process of the ceramic dielectric filter, the dielectric ceramic needs to be metallized, and the performance of the metal layer can directly influence the critical performances of the dielectric filter, such as the Q value, the reliability and the like.

At present, the method for metallizing the surface of the dielectric ceramic mainly comprises a silver spraying method, a screen printing method, an electroplating method, a vacuum evaporation method, a magnetron sputtering method and the like, commonly used metal electrode materials comprise Ni, Cu, Ag and the like, and silver has strong conductive capability, good thermal stability and good wettability with soldering tin, so that at present, the metal silver is generally adopted as the metallized layer on the surface of the dielectric ceramic. However, the existing method for metallizing the surface of the dielectric ceramic has the defects.

For example, when the metallization of the surface of the ceramic medium adopts a silver spraying or screen printing method, due to certain differences of silver paste formulas, screen printing parameters and sintering processes, the silver layer on the surface of the ceramic medium is not smooth enough, the conductivity of the film layer is reduced due to organic carriers in the silver paste, the silver layer is prone to peeling, bubbling, pinholes and other phenomena, the silver spraying process is serious in silver paste waste, and the silver paste recovery cost is high. Silver layers prepared by vacuum evaporation and electroplating have poor binding force with ceramic media, and the pollution of electroplating solution is serious. The magnetron sputtering method usually needs to deposit a plurality of transition layers or connecting layers of Cr, WC, Mo, Cu and the like, the preparation process is complex, a plurality of sputtering targets need to be linked, and the cost is high.

Therefore, the research on a novel environment-friendly, cost-controllable and high-quality metallization process has very important significance for the development of ceramic media.

Disclosure of Invention

The present application aims to overcome the above disadvantages of the prior art, and provides a composite dielectric ceramic and a preparation method thereof, so as to solve the technical problems of low bonding force between a metal layer and the dielectric ceramic, high cost, and the like caused by the existing metallization process on the surface of the dielectric ceramic.

Another objective of the present application is to provide a microwave filter to solve the technical problem of unstable performance of the microwave filter caused by poor bonding force between the metal layer and the dielectric ceramic in the existing microwave filter.

To achieve the above object, in one aspect of the present application, a composite dielectric ceramic is provided. The composite dielectric ceramic comprises a dielectric ceramic body, wherein an Ag layer is combined on the surface of the dielectric ceramic body, and the density of the Ag layer is increased in a gradient manner from the dielectric ceramic body to the direction of the outer surface of the Ag layer.

Further, the density range of the Ag layer is 7.5-10.1 g/cm³。

Further, the thickness of the Ag layer is 3-6 μm.

Further, the dielectric ceramic body is a microwave dielectric ceramic body.

The density of the Ag layer that this application composite dielectric ceramic surface contained is the gradient distribution from interior to exterior, consequently, the Ag layer that is close to the dielectric ceramic body has relative loose structure to can effectively release and reduce the stress between Ag layer and the dielectric ceramic body interface, and can alleviate the thermal stress or the mechanical stress that this application composite dielectric ceramic produced in the use, show the bonding strength who improves between Ag layer and the dielectric ceramic body, and avoid additionally addding the transition layer. And the Ag layer with the density gradient increasing from the inner surface to the outer surface has high surface quality, and the composite dielectric ceramic is endowed with low loss characteristic and low cost.

In another aspect of the application, a method for preparing the composite dielectric ceramic is provided. The preparation method of the composite dielectric ceramic comprises the following steps:

providing a dielectric ceramic body;

an Ag layer is formed on the surface of the dielectric ceramic body, and the density of the Ag layer is increased in a gradient manner from the dielectric ceramic body to the outer surface of the Ag layer.

Further, the method for forming the Ag layer on the surface of the dielectric ceramic body comprises the following steps:

depositing a metal target on the surface of the dielectric ceramic body by adopting a magnetron sputtering method to form an Ag layer; wherein, the magnetron sputtering pressure is gradually reduced along with the progress of magnetron sputtering.

Furthermore, the magnetron sputtering pressure is 4.0Pa to 0.2Pa, and the sputtering time is 20 min to 30 min.

Furthermore, the DC voltage of magnetron sputtering is 2000-3000V, and the current is 0.5-2.0A.

Furthermore, in the magnetron sputtering, the temperature of the dielectric ceramic body is 80-160 ℃.

Further, the degree of vacuum of the back surface in magnetron sputtering was 5X 10^-4Pa～1×10^-3Pa。

Furthermore, the argon gas flow in the magnetron sputtering is 20sccm to 50 sccm.

Further, before the step of forming the Ag layer on the surface of the dielectric ceramic body, the method also comprises the following steps of preprocessing the dielectric ceramic body:

firstly, grinding and cleaning the dielectric ceramic body, and then drying.

According to the preparation method of the composite dielectric ceramic, the Ag layer with the density gradually increased in a gradient manner from the inside to the outside is directly formed on the surface of the dielectric ceramic body, so that the stress between the formed Ag layer and the interface of the dielectric ceramic body is small, the bonding strength of the Ag layer and the interface of the dielectric ceramic body is high, the composite dielectric ceramic is stable in structure, and the composite dielectric ceramic has the characteristic of low thermal stress or mechanical stress generated in the using process. And the preparation method of the composite dielectric ceramic has controllable conditions, and effectively ensures the stable structure, low loss, electromagnetism and other properties of the prepared composite dielectric ceramic. In addition, a step of forming a transition layer is not additionally arranged between the Ag layer and the dielectric ceramic body, so that the economic cost for preparing the composite dielectric ceramic is effectively reduced.

In yet another aspect of the present application, a microwave filter is provided. The microwave filter is the composite dielectric ceramic, and a dielectric ceramic body contained in the composite dielectric ceramic is a microwave dielectric ceramic body.

Furthermore, the bonding force between the Ag layer and the microwave dielectric ceramic body reaches 38.2N/mm²。

Further, the insertion loss of the microwave filter is <1 dB.

This application microwave filter is owing to be this application composite dielectric ceramic, consequently, the thermal stress or the mechanical stress that this application microwave filter produced in the use, bonding strength between microwave dielectric ceramic body and the Ag layer, stable in structure, Ag layer surface quality is high, has low loss characteristic and low cost.

Drawings

In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings needed to be used in the detailed description of the present application or the prior art description will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic flow chart of a method for preparing a composite dielectric ceramic according to an embodiment of the present application.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application more clearly apparent, the present application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In this application, the term "and/or" describes an association relationship of associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a is present alone, A and B are present simultaneously, and B is present alone. Wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

In the present application, "at least one" means one or more, "a plurality" means two or more. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, "at least one (a), b, or c", or "at least one (a), b, and c", may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, and c may be single or plural, respectively.

It should be understood that, in various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, some or all of the steps may be executed in parallel or executed sequentially, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The weight of the related components mentioned in the description of the embodiments of the present application may not only refer to the specific content of each component, but also represent the proportional relationship of the weight among the components, and therefore, the content of the related components is scaled up or down within the scope disclosed in the description of the embodiments of the present application as long as it is scaled up or down according to the description of the embodiments of the present application. Specifically, the mass described in the specification of the embodiments of the present application may be a mass unit known in the chemical industry field such as μ g, mg, g, kg, etc.

In one aspect, embodiments of the present application provide a composite dielectric ceramic. The composite dielectric ceramic comprises a dielectric ceramic body, wherein an Ag layer is combined on the surface of the dielectric ceramic body, and the density of the Ag layer is increased in a gradient manner from the dielectric ceramic body to the outer surface of the Ag layer. Therefore, the density of the Ag layer contained in the composite dielectric ceramic is distributed in a gradient manner from the inner surface to the outer surface, and particularly the density of the Ag layer is increased in a gradient manner from the inner surface to the outer surface, so that the Ag layer close to the dielectric ceramic body is endowed with a relatively loose structure, the stress between the Ag layer and the interface of the dielectric ceramic body can be effectively released and reduced, meanwhile, the thermal stress or the mechanical stress generated in the using process of the composite dielectric ceramic in the embodiment of the application can be relieved, the bonding strength between the Ag layer and the dielectric ceramic body is obviously improved, and the structural stability of the composite dielectric ceramic in the embodiment of the application is improved. Meanwhile, the transition layer is prevented from being additionally arranged between the dielectric ceramic body and the Ag layer, and the composite dielectric ceramic of the embodiment of the application is reduced. And the Ag layer with the density gradient increasing from the inner surface to the outer surface has high surface quality, and the composite dielectric ceramic is endowed with low loss characteristic and low cost. In addition, the Ag layer has stronger electric conduction capability and good thermal stability, so that the composite dielectric ceramic has strong thermal stress or mechanical stress generated in the use process, stable structure, excellent low-loss characteristic and better wettability with soldering tin.

The composite dielectric ceramic of the embodiment of the present application may include any dielectric ceramic body, which may be specifically selected and adjusted according to the application requirements of the composite dielectric ceramic of the embodiment of the present application, and the morphology of the composite dielectric ceramic may also be adjusted and selected according to the application field or the requirements. In the embodiment of the application, the dielectric ceramic body is a microwave dielectric ceramic body of a microwave filter. The shape can be according to the common shape of the microwave filter or the shape after improvement.

In the embodiment, the density range of the Ag layer contained in the composite dielectric ceramic of the embodiment of the application is 7.5-10.1 g/cm³. From the surface of the dielectric ceramic body to the outer surface of the Ag layer, the density of the Ag layer gradually increases in the density range, namely, the density of the Ag layer gradually increases in a gradient manner, so that the structure of the Ag layer close to the surface of the dielectric ceramic body is a loose structure, the effect of stress release between the Ag layer and the interface of the dielectric ceramic body is effectively improved, the thermal stress or the mechanical stress generated in the using process of the composite dielectric ceramic in the embodiment of the application is further relieved, and the bonding strength between the Ag layer and the dielectric ceramic body is obviously improved. And the outer surface of the Ag layer is compact and high in quality, and the low loss characteristic of the composite dielectric ceramic can be obviously improved.

In the examples, the thickness of the Ag layer is typically, but not limited to, 3 to 6.5. mu.m, more preferably 3.4 to 6.5. mu.m, and still more preferably 3.4 to 6 μm, and more preferably 3 μm, 3.5. mu.m, 4 μm, 4.5. mu.m, 5. mu.m, 5.5. mu.m, 6 μm, etc. The thickness range can improve the function of the Ag layer, improve the thermal stress or mechanical stress generated in the using process of the composite dielectric ceramic and the structural stability, and has more excellent low-loss characteristics.

Correspondingly, the embodiment of the application also provides a preparation method of the composite dielectric ceramic in the embodiment of the above text application. The preparation method of the composite dielectric ceramic has the process flow as shown in figure 1, and comprises the following steps:

step S01: providing a dielectric ceramic body;

step S02: an Ag layer is formed on the surface of the dielectric ceramic body, and the density of the Ag layer is increased in a gradient manner from the dielectric ceramic body to the outer surface of the Ag layer.

The dielectric ceramic body in step S01 is the one described above. In an embodiment, the dielectric ceramic body is a microwave dielectric ceramic body of a microwave filter. The shape can be according to the common shape of the microwave filter or the shape after improvement.

Before forming the Ag layer on the surface of the dielectric ceramic body, the method also comprises the following steps of:

firstly, grinding and cleaning the dielectric ceramic body, and then drying.

Wherein, grinding the dielectric ceramic body can effectively control the grain diameter of the dielectric ceramic body and improve the surface quality such as smoothness and the like. In the embodiment, the grinding treatment may be, but not limited to, vibration grinding treatment, such as vibration grinding treatment using alumina balls having a diameter of 4mm to 8mm as vibration grinding particles.

And cleaning the dielectric ceramic body to remove impurities and the like on the surface of the dielectric ceramic body, or removing ceramic powder and the like remained on the surface after grinding treatment. In the examples, the cleaning treatment is ultrasonic cleaning, and in the specific examples, the solvents for ultrasonic cleaning are acetone and absolute ethyl alcohol.

And drying the cleaned dielectric ceramic body to effectively remove residual solvent in the cleaning process and avoid adverse effect on the quality of subsequent Ag layer formation. In an embodiment, the drying process is a heating drying process, such as a full drying process at 120-150 ℃, wherein the drying time in the temperature range may be, but not limited to, 40 min.

In step S02, the Ag layer formed on the surface of the dielectric ceramic body is the Ag layer contained in the composite dielectric ceramic, and therefore, the structure and material of the formed Ag layer are as described in the Ag layer contained in the composite dielectric ceramic, and for the sake of brevity, the structure, thickness, density, and other characteristics of the Ag layer formed in step S02 are not described herein again.

In an embodiment, the method for forming the Ag layer on the surface of the dielectric ceramic body comprises the following steps:

depositing a metal target on the surface of the dielectric ceramic body by adopting a magnetron sputtering method to form an Ag layer; wherein, the magnetron sputtering pressure is gradually reduced along with the progress of magnetron sputtering.

An Ag layer is deposited on the surface of the dielectric ceramic body by a magnetron sputtering method, the Ag layer with a loose structure is prepared under high sputtering pressure, the stress at the interface is released, then the sputtering pressure is continuously reduced, the density of the Ag layer is gradually improved, and the Ag layer structure with the density gradient increasing from the inner surface to the outer surface of the Ag layer is formed. And the Ag layer is formed by gradually reducing the magnetron sputtering pressure, so that on one hand, the thermal stress caused by the temperature difference caused by the temperature drop and cooling after the magnetron sputtering is finished due to the temperature rise of the dielectric ceramic body under the action of particle bombardment in the magnetron sputtering process can be relieved; on the other hand, the thermal stress or the mechanical stress generated in the use process of the prepared composite dielectric ceramic is further relieved, the good combination of the Ag layer and the dielectric ceramic body is improved, and the combination force and the low loss characteristic between the Ag layer and the dielectric ceramic body are greatly improved on the basis of improving the quality of the Ag layer.

In the embodiment, the magnetron sputtering pressure is 8.0Pa to 0.2Pa, and further is 4.0Pa to 0.5Pa, 5.0Pa to 0.8Pa, 6.0Pa to 1.0Pa, 6.0Pa to 0.2Pa, 8.0Pa to 1.0Pa, 8.0Pa to 0.5Pa and other magnetron sputtering pressures; the sputtering time is 20-30 min. In the magnetron sputtering, the magnetron sputtering pressure is gradually reduced along with the progress of the magnetron sputtering within the range of 8.0 Pa-0.2 Pa, so that the density of the Ag layer is gradually increased, the stress between the high Ag layer and the dielectric ceramic body is effectively relieved and released, and the bonding force between the high Ag layer and the dielectric ceramic body is improved. And simultaneously improves the low loss characteristic of the Ag layer.

In the embodiment, the direct-current voltage of magnetron sputtering is 2000-3000V; the current is 0.5 to 2.0A, and further 0.5 to 1.0A. In another embodiment, the temperature of the dielectric ceramic body is 80-160 ℃ in magnetron sputtering. In another embodiment, the degree of vacuum on the back surface in magnetron sputtering is 5X 10^-4Pa～1×10^-3Pa, further 5X 10^-4Pa～8×10^-4Pa. In another embodiment, the flow rate of argon gas in magnetron sputtering is 20sccm to 50sccm, and further 30sccm to 50sccm Pa. By controlling and optimizing the magnetron sputtering conditions and combining the magnetron sputtering pressure conditions, the density gradient increasing characteristic of the Ag layer is further optimized, the stress between the high Ag layer and the dielectric ceramic body is further relieved and released, the bonding force between the high Ag layer and the dielectric ceramic body is improved, and meanwhile, the low loss characteristic of the Ag layer is improved.

Therefore, the preparation method of the composite dielectric ceramic directly forms the Ag layer with the density gradually increased from the inside to the outside surface on the surface of the dielectric ceramic body by adopting magnetron sputtering and controlling the magnetron sputtering condition, so that the stress between the formed Ag layer and the interface of the dielectric ceramic body is small, the bonding strength of the Ag layer and the interface of the dielectric ceramic body is high, the composite dielectric ceramic has stable structure, and the composite dielectric ceramic has the characteristic of low thermal stress or mechanical stress generated in the using process. In addition, the preparation method of the composite dielectric ceramic in the embodiment of the application has controllable conditions, and the stable structure, low loss, electromagnetism and other properties of the prepared composite dielectric ceramic are effectively ensured. In addition, a step of forming a transition layer is not additionally arranged between the Ag layer and the dielectric ceramic body, so that the economic cost for preparing the composite dielectric ceramic is effectively reduced.

In another aspect, an embodiment of the present application provides a microwave filter. The microwave filter is the composite dielectric ceramic, and a dielectric ceramic body contained in the composite dielectric ceramic is a microwave dielectric ceramic body. Therefore, the microwave filter provided by the embodiment of the application generates thermal stress or mechanical stress in the using process, the bonding strength between the microwave dielectric ceramic body and the Ag layer is stable in structure, the surface quality of the Ag layer is high, and the microwave filter has the characteristics of low loss and low cost. Through detection, the bonding force between the Ag layer contained in the microwave filter, namely the composite dielectric ceramic and the microwave dielectric ceramic body reaches 38.2N/mm²And insertion loss of microwave filter<1dB。

The composite dielectric ceramic and the preparation method thereof according to the embodiments of the present application will be described below by way of examples.

Example 1

The embodiment provides a microwave filter and a preparation method thereof. The microwave filter comprises a microwave dielectric ceramic body and an Ag layer deposited on the surface of the microwave dielectric ceramic body.

The preparation method of the microwave filter comprises the following steps:

s1: providing a dielectric ceramic body:

s11: carrying out vibration grinding and ultrasonic cleaning on the dielectric ceramic, wherein the vibration grinding particles are alumina balls with the diameter of 4 mm; the ultrasonic cleaning solvent is acetone and absolute ethyl alcohol, and the cleaning time is 30 min;

s12: drying the medium ceramic subjected to ultrasonic cleaning at 120 ℃ for 40min by using water;

s2: putting the dielectric ceramic into a magnetron sputtering cavity until the dielectric ceramic reaches 5 multiplied by 10^-4Introducing argon after the background vacuum degree of Pa, opening a substrate for heating, generating argon plasma under high voltage, and performing magnetron sputtering coating under certain argon pressure by adopting a silver target material; the argon flow is 30 sccm; the substrate temperature is 120 ℃; the direct current voltage is 2000V, the current is 2.0A, the magnetron sputtering pressure is gradually reduced along with the sputtering time from 4.0Pa to 0.2Pa, and the sputtering time is 25 min.

Example 2

The embodiment provides a microwave filter and a preparation method thereof. The microwave filter comprises a microwave dielectric ceramic body and an Ag layer deposited on the surface of the microwave dielectric ceramic body.

The preparation method of the microwave filter comprises the following steps:

s1: providing a dielectric ceramic body:

s11: carrying out vibration grinding and ultrasonic cleaning on the dielectric ceramic, wherein the vibration grinding particles are alumina balls with the diameter of 4 mm; the ultrasonic cleaning solvent is acetone and absolute ethyl alcohol, and the cleaning time is 30 min;

s12: drying the medium ceramic subjected to ultrasonic cleaning at the drying temperature of 150 ℃ for 40 min;

s2: putting the dielectric ceramic into a magnetron sputtering cavity until the dielectric ceramic reaches 6 multiplied by 10^-4Introducing argon after the background vacuum degree of Pa, opening a substrate for heating, generating argon plasma under high voltage, and performing magnetron sputtering coating under certain argon pressure by adopting a silver target material; the argon flow is 35 sccm; the substrate temperature is 100 ℃; the direct current voltage is 2500V, the current is 1.5A, the magnetron sputtering pressure is gradually reduced along with the sputtering time from 5.0Pa to 0.8Pa, and the sputtering time is 25 min.

Example 3

The embodiment provides a microwave filter and a preparation method thereof. The microwave filter comprises a microwave dielectric ceramic body and an Ag layer deposited on the surface of the microwave dielectric ceramic body.

The preparation method of the microwave filter comprises the following steps:

s1: providing a dielectric ceramic body:

s11: carrying out vibration grinding and ultrasonic cleaning on the dielectric ceramic, wherein the vibration grinding particles are alumina balls with the diameter of 5 mm; the ultrasonic cleaning solvent is acetone and absolute ethyl alcohol, and the cleaning time is 30 min;

s12: drying the medium ceramic subjected to ultrasonic cleaning at 130 ℃ for 40min by using water;

s2: putting the dielectric ceramic into a magnetron sputtering cavity at 5 x 10^-4Introducing argon after the background vacuum degree of Pa, opening a substrate for heating, generating argon plasma under high voltage, and performing magnetron sputtering coating under certain argon pressure by adopting a silver target material; the argon flow is 40 sccm; the substrate temperature is 80 ℃; the direct current voltage is 2500V, the current is 2.0A, the magnetron sputtering pressure is gradually reduced along with the sputtering time from 4.0Pa to 0.5Pa, and the sputtering time is 25 min.

Example 4

The embodiment provides a microwave filter and a preparation method thereof. The microwave filter comprises a microwave dielectric ceramic body and an Ag layer deposited on the surface of the microwave dielectric ceramic body.

The preparation method of the microwave filter comprises the following steps:

s1: providing a dielectric ceramic body:

s11: carrying out vibration grinding and ultrasonic cleaning on the dielectric ceramic, wherein the vibration grinding particles are alumina balls with the diameter of 5 mm; the ultrasonic cleaning solvent is acetone and absolute ethyl alcohol, and the cleaning time is 30 min;

s12: drying the medium ceramic subjected to ultrasonic cleaning at 140 ℃ for 40 min;

s2: putting the dielectric ceramic into a magnetron sputtering cavity until the dielectric ceramic reaches 7 multiplied by 10^-4Introducing argon after the background vacuum degree of Pa, opening a substrate for heating, generating argon plasma under high voltage, and performing magnetron sputtering coating under certain argon pressure by adopting a silver target material; the argon flow is 25 sccm; the substrate temperature is 100 ℃; DC voltage 3000V, current 0.5A, magnetron sputtering pressureThe intensity is gradually reduced from 5.0Pa to 0.2Pa along with the sputtering time, and the sputtering time is 25 min.

Example 5

The embodiment provides a microwave filter and a preparation method thereof. The microwave filter comprises a microwave dielectric ceramic body and an Ag layer deposited on the surface of the microwave dielectric ceramic body.

The preparation method of the microwave filter comprises the following steps:

s1: providing a dielectric ceramic body:

s11: carrying out vibration grinding and ultrasonic cleaning on the dielectric ceramic, wherein the vibration grinding particles are alumina balls with the diameter of 6; the ultrasonic cleaning solvent is acetone and absolute ethyl alcohol, and the cleaning time is 30 min;

s12: drying the medium ceramic subjected to ultrasonic cleaning at 120 ℃ for 40min by using water;

s2: putting the dielectric ceramic into a magnetron sputtering cavity until the dielectric ceramic reaches 8 multiplied by 10^-4Introducing argon after the background vacuum degree of Pa, opening a substrate for heating, generating argon plasma under high voltage, and performing magnetron sputtering coating under certain argon pressure by adopting a silver target material; the argon flow is 20 sccm; the substrate temperature is 120 ℃; the direct current voltage is 3000V, the current is 1.0A, the magnetron sputtering pressure is gradually reduced along with the sputtering time from 6.0Pa to 0.2Pa, and the sputtering time is 25 min.

Example 6

The embodiment provides a microwave filter and a preparation method thereof. The microwave filter comprises a microwave dielectric ceramic body and an Ag layer deposited on the surface of the microwave dielectric ceramic body.

The preparation method of the microwave filter comprises the following steps:

s1: providing a dielectric ceramic body:

s11: carrying out vibration grinding and ultrasonic cleaning on the dielectric ceramic, wherein the vibration grinding particles are alumina balls with the diameter of 6 mm; the ultrasonic cleaning solvent is acetone and absolute ethyl alcohol, and the cleaning time is 30 min;

s12: drying the medium ceramic subjected to ultrasonic cleaning at 140 ℃ for 40 min;

s2: putting the dielectric ceramic into the magnetA sputtering control cavity is formed, and the sputtering control cavity reaches 9 multiplied by 10^-4Introducing argon after the background vacuum degree of Pa, opening a substrate for heating, generating argon plasma under high voltage, and performing magnetron sputtering coating under certain argon pressure by adopting a silver target material; the argon flow is 25 sccm; the substrate temperature is 130 ℃; the direct current voltage is 2500V, the current is 1.0A, the magnetron sputtering pressure is gradually reduced along with the sputtering time from 6.0Pa to 1.0Pa, and the sputtering time is 25 min.

Example 7

The embodiment provides a microwave filter and a preparation method thereof. The microwave filter comprises a microwave dielectric ceramic body and an Ag layer deposited on the surface of the microwave dielectric ceramic body.

The preparation method of the microwave filter comprises the following steps:

s1: providing a dielectric ceramic body:

s11: carrying out vibration grinding and ultrasonic cleaning on the dielectric ceramic, wherein the vibration grinding particles are alumina balls with the diameter of 7 mm; the ultrasonic cleaning solvent is acetone and absolute ethyl alcohol, and the cleaning time is 30 min;

s12: drying the medium ceramic subjected to ultrasonic cleaning at the drying temperature of 150 ℃ for 40 min;

s2: putting the dielectric ceramic into a magnetron sputtering cavity until the dielectric ceramic reaches 1 multiplied by 10^-3Introducing argon after the background vacuum degree of Pa, opening a substrate for heating, generating argon plasma under high voltage, and performing magnetron sputtering coating under certain argon pressure by adopting a silver target material; the argon flow is 45 sccm; the substrate temperature is 160 ℃; the direct current voltage is 3000V, the current is 1.5A, the magnetron sputtering pressure is gradually reduced along with the sputtering time from 8.0Pa to 0.5Pa, and the sputtering time is 25 min.

Example 8

The embodiment provides a microwave filter and a preparation method thereof. The microwave filter comprises a microwave dielectric ceramic body and an Ag layer deposited on the surface of the microwave dielectric ceramic body.

The preparation method of the microwave filter comprises the following steps:

s1: providing a dielectric ceramic body:

s11: carrying out vibration grinding and ultrasonic cleaning on the dielectric ceramic, wherein the vibration grinding particles are alumina balls with the diameter of 8 mm; the ultrasonic cleaning solvent is acetone and absolute ethyl alcohol, and the cleaning time is 30 min;

s12: drying the medium ceramic subjected to ultrasonic cleaning at the drying temperature of 150 ℃ for 40 min;

s2: putting the dielectric ceramic into a magnetron sputtering cavity until the dielectric ceramic reaches 5 multiplied by 10^-4Introducing argon after Pa vacuum degree, opening a substrate for heating, generating argon plasma under high voltage, and performing magnetron sputtering coating under certain argon pressure by adopting a silver target material; the argon flow is 50 sccm; the substrate temperature is 150 ℃; the direct current voltage is 2000V, the current is 2.0A, the magnetron sputtering pressure is gradually reduced along with the sputtering time from 8.0Pa to 1.0Pa, and the sputtering time is 25 min.

Comparative example 1

The present comparative example provides a microwave filter and a method of manufacturing the same. The microwave filter comprises a microwave dielectric ceramic body and an Ag layer deposited on the surface of the microwave dielectric ceramic body.

The preparation method of the microwave filter comprises the following steps:

s1: providing a dielectric ceramic body:

s11: carrying out vibration grinding and ultrasonic cleaning on the dielectric ceramic, wherein the vibration grinding particles are alumina balls with the diameter of 4 mm; the ultrasonic cleaning solvent is acetone and absolute ethyl alcohol, and the cleaning time is 30 min;

s12: drying the medium ceramic subjected to ultrasonic cleaning at 120 ℃ for 40min by using water;

s2: putting the dielectric ceramic into a magnetron sputtering cavity until the dielectric ceramic reaches 5 multiplied by 10^-4Introducing argon after the background vacuum degree of Pa, opening a substrate for heating, generating argon plasma under high voltage, and performing magnetron sputtering coating under certain argon pressure by adopting a silver target material; the argon flow is 30 sccm; the substrate temperature is 120 ℃; the direct current voltage is 2000V, the current is 2.0A, the magnetron sputtering pressure is fixed to be 4.0Pa, and the sputtering time is 25 min.

Comparative example 2

The present comparative example provides a microwave filter and a method of manufacturing the same. The microwave filter comprises a microwave dielectric ceramic body and an Ag layer deposited on the surface of the microwave dielectric ceramic body.

The preparation method of the microwave filter comprises the following steps:

s1: providing a dielectric ceramic body:

s11: carrying out vibration grinding and ultrasonic cleaning on the dielectric ceramic, wherein the vibration grinding particles are alumina balls with the diameter of 4; the ultrasonic cleaning solvent is acetone and absolute ethyl alcohol, and the cleaning time is 30 min;

s12: drying the medium ceramic subjected to ultrasonic cleaning by water, wherein the drying temperature in the step S2 is 120 ℃, and the drying time is 40 min;

s2: putting the dielectric ceramic into a magnetron sputtering cavity until the dielectric ceramic reaches 5 multiplied by 10^-4Introducing argon after the background vacuum degree of Pa, opening a substrate for heating, generating argon plasma under high voltage, and performing magnetron sputtering coating under certain argon pressure by adopting a silver target material; the argon flow is 30 sccm; the substrate temperature is 120 ℃; the direct current voltage is 2000V, the current is 2.0A, the magnetron sputtering pressure is fixed to be 0.2Pa, and the sputtering time is 25 min.

Microwave filter related performance test

The thickness of the Ag layer, the adhesion of the Ag layer to the dielectric ceramic body, and the insertion loss of the microwave filter were measured for each of the microwave filters provided in the above examples, and the measurement results are shown in table 1 below.

TABLE 1

As can be seen from table 1, in the Ag layer material with a gradient structure on the surface of the dielectric ceramic provided in the embodiment of the present application, the Ag layer material with a gradient structure has a composite structure whose density changes with depth, when the Ag layer material is prepared by a magnetron sputtering method, the dielectric ceramic material is used as a base, the silver layer with a loose structure prepared under a high magnetron sputtering pressure is used as a bottom layer, the stress between the ceramic/Ag layers is released by controlling the sputtering pressure to gradually change from high to low, and the density of the Ag layer is gradually increased along with the thickening and continuous reduction of the magnetron sputtering pressure of the Ag layer, so that the Ag layer with a density gradient changing from inside to outside is formed. The Ag layer structure with the density increasing in a gradient manner can relieve the temperature rise of a base body due to the particle bombardment effect in the magnetron sputtering process and the thermal stress caused by the temperature difference caused by cooling after the magnetron sputtering is finished, and can relieve the thermal stress or the mechanical stress generated in the use process of the microwave filter, thereby ensuring the good combination of the Ag layer and the medium. The prepared Ag layer has high bonding strength with the dielectric ceramic body and low insertion loss, and a transition layer does not need to be pre-sputtered on the surface of the dielectric ceramic body. In addition, the preparation method of the surface gradient structure Ag layer of the dielectric ceramic body, provided by the application, is simple in process, low in cost and suitable for large-scale industrial production.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.