阅读说明：本技术 一种双锡层陶瓷导电材料及其制备方法 (Double-tin-layer ceramic conductive material and preparation method thereof ) 是由 胡昕 张红艳 曲元萍 于 2020-06-30 设计创作，主要内容包括：本发明提供了一种陶瓷导电材料及其制备方法,所述陶瓷导电材料包括陶瓷基体以及形成在所述陶瓷基体表面的金属化层,其特征在于：所述金属化层包括由内向外依次设置的化学镀锡层、电镀铜层、电镀锡层和锡保护层；所述化学镀锡层的厚度为0.2μm-0.5μm,所述电镀铜层的厚度为6μm-10μm,所述电镀锡层的厚度为2μm-3μm。通过锡的快速浸润以及化学反应使锡与陶瓷基体表面形成稳定的化学键,作为连接层使其与陶瓷基体牢固结合,增加了镀层与陶瓷的结合力；同时可以实现陶瓷表面的导电化处理。(The invention provides a ceramic conductive material and a preparation method thereof, wherein the ceramic conductive material comprises a ceramic matrix and a metallization layer formed on the surface of the ceramic matrix, and is characterized in that: the metallization layer comprises a chemical tin plating layer, an electroplated copper layer, an electroplated tin layer and a tin protection layer which are arranged in sequence from inside to outside; the thickness of the chemical tin plating layer is 0.2-0.5 μm, the thickness of the copper electroplating layer is 6-10 μm, and the thickness of the tin electroplating layer is 2-3 μm. The tin and the surface of the ceramic matrix form a stable chemical bond through the rapid infiltration and chemical reaction of the tin, and the stable chemical bond is used as a connecting layer to be firmly combined with the ceramic matrix, so that the binding force of a plating layer and the ceramic is increased; and meanwhile, the conductive treatment of the ceramic surface can be realized.)

1. A ceramic conductive material comprising a ceramic base and a metallized layer formed on a surface of the ceramic base, wherein: the metallization layer comprises a chemical tin plating layer, an electroplated copper layer, an electroplated tin layer and a tin protection layer which are arranged in sequence from inside to outside; the thickness of the chemical tin plating layer is 0.2-0.5 μm, the thickness of the copper electroplating layer is 6-10 μm, and the thickness of the tin electroplating layer is 2-3 μm.

2. A method for preparing a ceramic conductive material according to claim 1, comprising:

preparing a chemical tin plating layer: performing chemical tin plating treatment on the ceramic substrate to obtain a chemical tin plating layer;

preparing an electroplated copper layer: carrying out electro-coppering treatment on the ceramic substrate subjected to the chemical tinning treatment to obtain an electro-coppering layer;

annealing treatment: carrying out high-temperature annealing treatment on the ceramic substrate after copper electroplating;

preparing a tin layer: performing electrotinning treatment on the annealed ceramic substrate to form an electrotinning layer;

preparing a tin protective layer: and (3) immersing the tinned ceramic substrate into a tin protective agent, washing with water and drying after immersion to obtain the ceramic substrate with the metallization layer.

3. The method for producing a ceramic conductive material according to claim 2, characterized in that: in the preparation of the chemical tin plating layer, the ceramic substrate is soaked in palladium and then is soaked in a chemical tin plating bath for 10-30s to obtain the chemical tin plating layer.

4. The ceramic conductive material according to claim 2The preparation method of the material is characterized by comprising the following steps: in the preparation of the electroplated copper layer, the ceramic substrate subjected to chemical tin plating treatment is used as a cathode, the phosphor copper plate is used as an anode, and the current density is 1.5-2.5A/dm²And electroplating at 20-30 deg.C for 15-30min to form a copper electroplating layer.

5. The method for producing a ceramic conductive material according to claim 2, characterized in that: the annealing treatment is sintering for 30-60 min at 600-800 ℃ under the condition of inert gas.

6. The method for producing a ceramic conductive material according to claim 2, characterized in that: in the preparation of the tin layer, the annealed ceramic substrate is used as a cathode, the pure tin plate is used as an anode, and the current density is 0.05-0.15A/dm²And electroplating for 4-6 min at 20-30 ℃.

Technical Field

The invention relates to a conductive material, in particular to a double-tin-layer ceramic conductive material and a preparation method thereof.

Background

With the development of 5G networks, 5G base stations develop towards miniaturization, light weight and high integration, MassiveMIMO technology multiplies the number of antennas, and thus the demand for filters will increase greatly. The 5G ceramic filter selects ceramic as a transmission medium material, has the advantages of high Q value, low insertion loss, high dielectric constant, low loss, small volume, light weight, low cost and the like, and is bound to become the mainstream of the 5G base station filter.

The conventional treatment method for metallizing ceramic surfaces (the current industrial method) is mainly characterized in that metal powder coating is brushed or sprayed on the ceramic surfaces, and then fillers and solvents are removed by a sintering method to obtain metallized layers which play a role in electric conduction. 201310392098.5, 201480007836.2, 201510794320.3, 201710118096.5; 201810259217.2, respectively; 201910787991.5, respectively; 202010008271.7, all of which use different metal powders, or slurries thereof, to achieve a metallized coating. In actual mass production, silver paste (solid content is 65-85%) is used, imported superfine silver powder is selected as a main conductive material, pre-sintering is carried out after brushing is finished, and then high-temperature sintering is carried out, so that a material of metal silver on the surface of ceramic is obtained and used as a core component of the ceramic filter.

This method has the following problems:

(1) in order to achieve a certain conductive effect, a metal layer with the thickness of about 10 micrometers is generally required to be sprayed and brushed, the uniformity of the process is difficult to control, and particularly in holes, multiple times of circulating operation is often required;

(2) in order to realize the conductive effect, the thickness of silver needs to be about 10 micrometers, in the specific production, due to the uniformity problem, in order to realize that the place difficult to attach can meet the requirement, the thickness of other places often exceeds 3-10 times, the thickness needs to be reduced through a subsequent grinding process, a large amount of silver is consumed, and the cost is very expensive;

(3) the superfine silver powder used in the existing silver paste process is mainly obtained through import, and the technology of the aspect is much laggard in China;

(4) when the ceramic filter produced by using the silver paste process is welded, the ceramic and the metal layer are easily separated due to the fact that the difference between the thermal expansion coefficient of the metal and the thermal expansion coefficient of the ceramic is large, and the yield of the product is reduced.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a double-tin-layer ceramic conductive material which has good bonding force, excellent conductive performance, low cost and easy industrial production and contains a metalized layer.

Still another object of the present invention is to provide a method for preparing the above ceramic conductive material having excellent properties.

In order to achieve the technical object, the present invention provides a dual tin layer ceramic conductive material, which includes a ceramic substrate and a metallization layer formed on a surface of the ceramic substrate, and is characterized in that: the metallization layer comprises a chemical tin plating layer, an electroplated copper layer, an electroplated tin layer and a tin protection layer which are arranged in sequence from inside to outside; the thickness of the chemical tin plating layer is 0.2-0.5 μm, the thickness of the copper electroplating layer is 6-10 μm, and the thickness of the tin electroplating layer is 2-3 μm.

According to the double-tin-layer ceramic conductive material, the metal tin is directly connected with the ceramic by chemical tin plating, the tin has good wettability at high temperature, the chemical tin plating layer contains a small amount of tin oxide, and the tin oxide can form a chemical reaction with an oxide in a ceramic matrix at high temperature to form a metal composite oxide, so that the bonding force between the tin layer and the ceramic matrix is greatly improved (figure 1); the copper layer is used as the main conductive layer, so that the conductive film has better conductivity and lower preparation cost; the tin layer is used as outer metal, so that the copper layer can be protected, the copper layer is prevented from being oxidized, and meanwhile, the effect of promoting welding bonding force can be achieved.

The invention also provides a preparation method of the ceramic conductive material, which comprises the following steps:

preparing a chemical tin plating layer: performing chemical tin plating treatment on the ceramic substrate to obtain a chemical tin plating layer;

preparing an electroplated copper layer: carrying out electro-coppering treatment on the ceramic substrate subjected to the chemical tinning treatment to obtain an electro-coppering layer;

annealing treatment: carrying out high-temperature annealing treatment on the ceramic substrate after copper electroplating;

preparing a tin layer: performing electrotinning treatment on the annealed ceramic substrate to form an electrotinning layer;

preparing a tin protective layer: and (3) immersing the tinned ceramic substrate into a tin protective agent, washing with water and drying after immersion to obtain the ceramic substrate with the metallization layer.

The preparation method of the double-tin-layer ceramic conductive material also comprises the step of pretreating the ceramic matrix. In one embodiment of the present invention, the pre-treatment comprises: cleaning and drying.

Cleaning, namely putting the ceramic substrate into ultrasonic cleaning for ultrasonic cleaning (10min), and drying in the air after cleaning; then putting into ethanol for ultrasonic cleaning (10 min); after cleaning, vacuum drying is carried out (50-80 ℃ C.; 5-10 min).

The preparation method of the double-tin-layer ceramic surface metal layer comprises the steps of chemical tin plating, specifically comprises two steps of palladium soaking and chemical tin plating;

the step of dipping palladium is to dip the cleaned ceramic substrate into a palladium dipping solution, and treat for 8-15 min under the condition of ultrasonic waves; the palladium leaching solution is conventional and specifically comprises 3g/L of palladium chloride, 200g/L of sodium chloride, 5g/L of sodium stannate and 10g/L of hydrochloric acid;

the chemical tin plating step is to immerse the ceramic substrate after palladium immersion into a chemical tin plating bath, and dip-plate the ceramic substrate for 10-30s at the temperature of 20-30 ℃ to obtain a chemical tin plating layer; the chemical tin plating solution comprises 10g/L of stannous chloride, 40g/L of hydrochloric acid, 45g/L of reducing agent and 35g/L of stabilizing agent;

the preparation method of the ceramic conductive material comprises the following steps of copper electroplating: using a chemically tinned ceramic matrix as a cathode and a phosphor copper plate as an anode, and performing a current density of 1.5-2.5A/dm²Electroplating at 20-30 deg.C for 15-30min to form a copper electroplating layer (the electroplating solution is conventional and comprises copper sulfate 150g/L, sulfuric acid 150g/L, hydrochloric acid 50ppm, brightener 1g/L, carrier 10g/L, and leveling agent 15 g/L).

The annealing step in the preparation method of the ceramic conductive material comprises the following steps: sintering at 600-800 ℃ for 30-60 min under the condition of inert gas.

The preparation method of the ceramic conductive material comprises the following steps: the annealed ceramic substrate is used as a cathode, a pure tin plate is used as an anode, and the current density is 0.05-0.15A/dm²Electroplating at 20-30 deg.C for 4-6 min (the tin plating solution is conventional and comprises 25g/L of stannous methanesulfonate, 150g/L of methanesulfonic acid and 40g/L of electroplating additive). According to the preparation method of the double-tin-layer ceramic conductive material, stable chemical bonds are formed between tin and the surface of the ceramic matrix through rapid infiltration and chemical reaction of tin, so that the tin and the ceramic matrix are firmly combined, and the bonding force of a coating and ceramic is increased; meanwhile, the conductive treatment of the ceramic surface can be realized; by using the method of copper electroplating, the uniformity of the plating layer can reach more than 95 percent; the electroplated copper layer is used as the main conductive layer, so that the use of silver is greatly reduced, and the material cost is reduced.

The preparation method of the ceramic conductive film can solve the problems of binding force, uniformity and the like in the brushing process, so that the prepared ceramic conductive film has the characteristics of good binding force, uniform coating, high conductivity, low price and the like.

Drawings

Fig. 1 is a schematic structural diagram of a double tin layer ceramic conductive material in embodiment 1 of the present invention.

Detailed Description