阅读说明：本技术 特高纯氧化铝陶瓷金属化方法 (Metallization method for ultra-high purity alumina ceramic ) 是由 罗毅 段冰 尚华 林贵洪 于 2020-05-18 设计创作，主要内容包括：本发明属于电子功能陶瓷材料技术领域,具体涉及一种特高纯氧化铝陶瓷金属化方法。针对氧化铝陶瓷金属化烧结过程导致的陶瓷基体强度低、热导率及气密性差等问题,本发明提供了一种特高纯氧化铝陶瓷金属化方法,包括以下步骤：a、称取原材料粉体,分散于酒精,球磨、烘干,制备金属化浆料添加剂；b、将钼粉、三氧化钼粉、锰粉、金属化浆料添加剂混合,得到粉料,球磨,制得金属化粉料；c、金属化粉料振磨,即得金属化浆料；d、将金属化浆料印刷或涂覆后烧结,得到金属化产品。本发明的金属化浆料烧结温度低于现有烧结温度,可多次金属化烧结,提高金属化层厚度,镀镍后,金属化层的剥离效果好,剥离强度高,金属化抗拉强度性能好。(The invention belongs to the technical field of electronic functional ceramic materials, and particularly relates to a metallization method of an ultra-high-purity alumina ceramic. Aiming at the problems of low ceramic matrix strength, poor thermal conductivity and air tightness and the like caused by the metallization sintering process of the alumina ceramic, the invention provides an ultra-high purity alumina ceramic metallization method, which comprises the following steps: a. weighing raw material powder, dispersing in alcohol, ball-milling, drying, and preparing a metalized slurry additive; b. mixing molybdenum powder, molybdenum trioxide powder, manganese powder and a metallization slurry additive to obtain powder, and performing ball milling to obtain metallization powder; c. vibrating and grinding the metallization powder to obtain metallization slurry; d. and printing or coating the metallization slurry and then sintering to obtain a metallization product. The sintering temperature of the metallization paste is lower than the existing sintering temperature, the metallization paste can be subjected to metallization sintering for multiple times, the thickness of a metallization layer is increased, and after nickel plating, the stripping effect of the metallization layer is good, the stripping strength is high, and the metallization tensile strength performance is good.)

1. The metallization method of the ultra-high purity alumina ceramic is characterized by comprising the following steps:

a. preparing a metallization slurry additive:

according to mass percent of Al₂O₃40～60％、SiO₂30-50%, CaO 2-7%, MgO 2-5% and Y₂O₃Weighing 1-3% of raw material powder;

dispersing the raw material powder into alcohol added with a ball milling medium, ball milling and drying to obtain a metalized slurry additive;

b. preparing metallized powder:

mixing 65-70% of molybdenum powder, 3-8% of molybdenum trioxide powder, 5-12% of manganese powder and 10-27% of metalized slurry additive by mass percent to obtain powder, and then mixing the powder with the metalized slurry additive by weightCarrying out ball milling treatment on agate ceramic balls at a ratio of 1: 1-2 to obtain metalized powder;

c. preparing a metallization slurry:

metallization powder material, adhesive and binder in weight ratioThe agate ceramic balls are 1: 0.3-0.4: 1, are vibrated and ground for 24-36 h, and are pressurized and sieved by a screen with 250-300 meshes, so that metalized slurry is obtained;

d. metallization and sintering:

and c, printing or coating the metalized slurry prepared in the step c on the surface of the ultra-high purity alumina ceramic matrix, drying and sintering after each printing or coating to obtain a metalized product.

2. The method of metallizing an ultra-high purity alumina ceramic according to claim 1, wherein: the weight ratio of the raw material powder in the step a to the alcohol and the ball milling medium is 1: 1.5-2.

3. The method of metallizing an ultra-high purity alumina ceramic according to claim 1, wherein: the particle diameter of the ball milling medium in the step a isAgate balls or alumina ceramic balls.

4. The method of metallizing an ultra-high purity alumina ceramic according to claim 1, wherein: the volume fraction of ethanol in the alcohol in the step a is 50-70%.

5. The method of metallizing an ultra-high purity alumina ceramic according to claim 1, wherein: the SiO₂Particle size D of the powder₅₀≤0.5μm。

6. The method of metallizing an ultra-high purity alumina ceramic according to claim 1, wherein: the Al is₂O₃、CaO、MgO、Y₂O₃The particle sizes of the molybdenum powder, the molybdenum trioxide powder and the manganese powder are all less than or equal to 1 mu m.

7. The method of metallizing an ultra-high purity alumina ceramic according to claim 1, wherein: the composition of the adhesive in step c comprises: the weight percentage of the additive is 3-5% of ethyl cellulose, 87-94% of terpineol, 2-5% of castor oil and 1-3% of fish oil.

8. The method of metallizing an ultra-high purity alumina ceramic according to claim 1, wherein: the preparation steps of the adhesive in the step c are as follows: drying ethyl cellulose, terpineol, castor oil and fish oil for 4-6 hours at 100-120 ℃, stirring until the ethyl cellulose is completely dissolved, and filtering by adopting a 250-300 mesh screen.

9. The method of metallizing an ultra-high purity alumina ceramic according to claim 1, wherein: and d, drying at 100-150 ℃ when printing the ultra-high purity alumina ceramic matrix, controlling the sintering temperature at 1400-1500 ℃, and keeping the temperature for 30-60 minutes.

10. The method of metallizing an ultra-high purity alumina ceramic according to claim 1, wherein: in the step d, when the ultra-high purity alumina ceramic matrix is coated, the coating is carried out for N times, the sintering temperature of the first N-1 times is controlled to be 1300-1400 ℃, the sintering temperature of the Nth time is controlled to be 1400-1500 ℃, drying is carried out at 100-150 ℃ after each coating, and the heat preservation is carried out for 30-60 minutes in each sintering.

Technical Field

The invention belongs to the technical field of electronic functional ceramic materials, and particularly relates to a metallization method of an ultra-high-purity alumina ceramic.

Background

With the development of electronic components towards high power and miniaturization, alumina ceramics are widely used in the fields of military communication, remote sensing and remote measuring electronic countermeasure, photoelectric technology and the like due to the characteristics of large volume resistivity, high breaking strength, high hardness, low dielectric loss, small linear expansion coefficient, high insulating property, capability of being welded and sealed with metal and the like, and become an indispensable important raw material for the production of microelectronic devices (thick and thin film circuits, high-power semiconductor devices) and photoelectric devices (infrared detection and imaging).

At present, alumina ceramic metallization methods are different at home and abroad, wherein the most important method is an active metallization method which is mainly divided into a molybdenum method and a tungsten method, and the method is largely used in industrial production due to relatively low cost and low requirement on equipment. However, the method can cause secondary growth of ceramic grains in the metallization sintering process, reduce the mechanical strength of the ceramic matrix, and influence the thermal conductivity and the air tightness of the metallized ceramic, thereby influencing the performance of the whole electronic component or device after sealing.

In order to solve the problems, the invention provides an ultra-high purity alumina ceramic metallization and a preparation method thereof.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the ceramic matrix has the problems of low strength, poor thermal conductivity and air tightness and the like caused by the metallization sintering process of the alumina ceramic.

The technical scheme for solving the technical problems comprises the following steps: provides a metallization method of ultra-high purity alumina ceramics. The method of the invention comprises the following steps:

a. preparing a metallization slurry additive:

according to mass percent of Al₂O₃40～60％、SiO₂30-50%, CaO 2-7%, MgO 2-5% and Y₂O₃Weighing 1-3% of raw material powder;

dispersing the raw material powder into alcohol added with a ball milling medium, ball milling and drying to obtain a metalized slurry additive;

b. preparing metallized powder:

mixing 65-70% of molybdenum powder, 3-8% of molybdenum trioxide powder, 5-12% of manganese powder and 10-27% of metalized slurry additive by mass percent to obtain powder, and then mixing the powder with the metalized slurry additive by weightCarrying out ball milling treatment on agate ceramic balls at a ratio of 1: 1-2 to obtain metalized powder;

c. preparing a metallization slurry:

metallization powder material, adhesive and binder in weight ratioThe agate ceramic balls are 1: 0.3-0.4: 1, are vibrated and ground for 24-36 h, and are pressurized and sieved by a screen with 250-300 meshes, so that metalized slurry is obtained;

d. metallization and sintering:

and c, printing or coating the metalized slurry prepared in the step c on the surface of the ultra-high purity alumina ceramic matrix, drying and sintering after each printing or coating to obtain a metalized product.

Wherein the weight ratio of the raw material powder in the step a to the alcohol and the ball milling medium is 1: 1.5-2.

Wherein the particle size of the ball milling medium in the step a isAgate balls or alumina ceramic balls.

Wherein the volume fraction of ethanol in the alcohol in the step a is 50-70%.

Wherein, the raw material powder, molybdenum trioxide powder, manganese powder, ethyl cellulose, terpineol, castor oil and fish oil are analytically pure.

Wherein, the SiO₂Particle size D of the powder₅₀≤0.5μm。

Wherein, said Al₂O₃、CaO、MgO、Y₂O₃The particle sizes of the molybdenum powder, the molybdenum trioxide powder and the manganese powder are all less than or equal to 1 mu m.

Wherein the composition of the adhesive in the step c comprises: the weight percentage of the additive is 3-5% of ethyl cellulose, 87-94% of terpineol, 2-5% of castor oil and 1-3% of fish oil.

Wherein the preparation step of the adhesive in the step c is as follows: drying ethyl cellulose, terpineol, castor oil and fish oil for 4-6 hours at 100-120 ℃, stirring until the ethyl cellulose is completely dissolved, and filtering by adopting a 250-300 mesh screen.

And d, drying at 100-150 ℃ when printing the ultra-high purity alumina ceramic matrix, controlling the sintering temperature at 1400-1500 ℃, and keeping the temperature for 30-60 minutes.

In the step d, when the ultra-high purity alumina ceramic matrix is coated, the coating is carried out for N times, the sintering temperature of the first N-1 times is controlled to be 1300-1400 ℃, the sintering temperature of the Nth time is controlled to be 1400-1500 ℃, drying is carried out at 100-150 ℃ after each coating, and the heat preservation is carried out for 30-60 minutes in each sintering.

Compared with the prior art, the invention has the beneficial effects that:

1. the sintering temperature of the ultra-high purity alumina ceramic metalized slurry provided by the invention is 1300-1500 ℃, which is lower than about 50 ℃ in the prior art, so that the negative influence on an ultra-high purity alumina ceramic matrix caused by a higher one-time sintering temperature is reduced, the repeated sintering of metallization becomes possible, and the thickness of a metalized layer is increased by the method; meanwhile, the ultra-high purity alumina ceramic metalized slurry has strong permeability, so that the thickness of a metalized layer sintered once can be increased; in addition, the slurry has better fluidity, is not only limited to printing of ultra-high purity alumina ceramic products, but also can be attached to a cylindrical or special-shaped ultra-high purity alumina ceramic substrate in a coating way; the metallization slurry is not only suitable for 99.5 percent alumina ceramics, but also suitable for 95 percent alumina-based composite ceramics such as alumina ceramics, and has wide application range.

2. After the ultra-high purity aluminum oxide metalized product prepared by the metallization method is plated with nickel, the metallization layer has good stripping effect, high stripping strength and good metallization tensile strength performance, and the average tensile strength is not less than 120MPa (the ultra-high purity aluminum oxide metalized product prepared by the existing metallization method has poor stripping effect, low stripping strength and poor metallization tensile strength performance, and the average tensile strength is not more than 60MPa), so that the requirements of vacuum devices, thick and thin film circuits, high-power semiconductor devices and photoelectric devices (infrared detection and imaging) on the performance of the metallized aluminum oxide ceramic product can be met.

Detailed Description

The invention provides a metallization method of ultra-high purity alumina ceramics, which comprises the following steps:

a. preparing a metallization slurry additive:

according to mass percent of Al₂O₃40～60％、SiO₂30-50%, CaO 2-7%, MgO 2-5% and Y₂O₃Weighing 1-3% of raw material powder; wherein SiO is₂Particle size D of the powder₅₀≤0.5μm，Al₂O₃、CaO、MgO、Y₂O₃The particle sizes of the particles are less than or equal to 1 mu m; the raw material powder is analytically pure;

dispersing raw material powder in alcohol at a weight ratio of raw material powder to alcoholBall milling media are 1: 1.5-2, and drying are carried out to obtain the metalized slurry additive;

b. preparing metallized powder:

mixing 65-70% of molybdenum powder, 3-8% of molybdenum trioxide powder, 5-12% of manganese powder and 10-27% of metalized slurry additive by mass percent to obtain powder, and then mixing the powder with the metalized slurry additive by weightCarrying out ball milling treatment on agate ceramic balls at a ratio of 1: 1-2 to obtain metalized powder; the particle sizes of the molybdenum powder, the molybdenum trioxide powder and the manganese powder are less than or equal to 1 mu m, and all the molybdenum powder, the molybdenum trioxide powder and the manganese powder are analytically pure;

c. preparing a metallization slurry:

metallization powder material, adhesive and binder in weight ratioThe agate ceramic balls are 1: 0.3-0.4: 1, are vibrated and ground for 24-36 h, and are pressurized and sieved by a screen with 250-300 meshes, so that metalized slurry is obtained;

the adhesive composition comprises: 3-5% of ethyl cellulose, 87-94% of terpineol, 2-5% of castor oil and 1-3% of fish oil in percentage by weight;

d. metallization and sintering:

and c, printing or coating the metalized slurry prepared in the step c on the surface of the ultra-high purity alumina ceramic matrix, drying and sintering after each printing or coating to obtain a metalized product.

In the method for metallizing the ultrahigh-purity aluminum oxide ceramic, the purity and the granularity of the raw materials are limited, and the initial ball milling and refining treatment of the metal molybdenum powder can ensure the activity of the powder to the greatest extent, reduce the sintering temperature to a certain extent, increase the permeation strength of the slurry and obtain a thicker single-sintering metallized layer. Specifically, SiO₂The wettability of the metal powder to the ceramic can be improved, and the air tightness is increased; al (Al)₂O₃The connection between the metal frameworks can be increased, and the sealing strength is increased; by adding the active agents CaO and MgO, the high-temperature sintering glass phase of the metalized slurry is increased, so that the diffusion capacity of the glass phase of the metalized slurry is enhanced, high-temperature liquid phase sintering is formed, and sintering permeation of a metalized layer and a ceramic matrix is facilitated; by addition of active agent Y₂O₃And the abnormal growth of alumina crystals in the liquid phase sintering process is prevented, and the sintering compactness of the metallized layer and the ceramic matrix is facilitated.

In the ultra-high purity alumina ceramic metallization slurry provided by the invention, the metallization molybdenum powder is taken as a main body, and a certain amount of molybdenum trioxide powder is used as an auxiliary material, so that the metallization sintering temperature can be reduced, the connection strength with a ceramic matrix is increased, and a compact metallization layer is formed; and the manganese powder is added to generate MnO under the action of reducing wet hydrogen atmosphere, and the MnO can play a good role in reducing the viscosity of the slurry and can obtain the lowest eutectic point to the maximum extent. The method is characterized in that 65-70% of molybdenum powder, 3-8% of molybdenum trioxide powder and 5-12% of manganese powder are mixed, the metallized molybdenum powder is used as a main material, a small amount of molybdenum trioxide powder and manganese powder are added, a metal powder sintering mechanism is applied, and the low-temperature metallized powder dense sintering is realized through the high-temperature liquid phase action of a metallized slurry additive, so that the sintering temperature of the molybdenum series metallized slurry is effectively reduced by about 50 ℃ (1300-1500 ℃). Therefore, the negative influence on the ultrahigh-purity alumina ceramic matrix caused by the higher sintering temperature at one time is reduced, the repeated sintering of metallization becomes possible, and the thickness of the metallization layer can be increased by the method. After the ultra-high purity aluminum oxide metalized product prepared by the metallization method is plated with nickel, the metallization layer has good stripping effect, high stripping strength and good metallization tensile strength performance, and the average tensile strength is more than or equal to 120 MPa.

The following examples are intended to illustrate specific embodiments of the present invention without limiting the scope of the invention to the examples.