阅读说明：本技术 一种在陶瓷介质基板表面金属化的方法及陶瓷介质基板 (Method for metalizing surface of ceramic dielectric substrate and ceramic dielectric substrate ) 是由 苏祺益 严勇 潘甲东 刘剑林 谢艺精 庄梦琪 于 2021-08-31 设计创作，主要内容包括：本发明提供一种在陶瓷介质基板表面金属化的方法及陶瓷介质基板,方法包括如下步骤：A、依次对原始陶瓷介质基板本体进行研磨和/或抛光；B、对经步骤A后的陶瓷介质基板本体进行预处理；C、对烧结后的陶瓷介质基板本体依次利用丙酮溶液、酒精、微酸性清洗液和去离子水进行超声波清洗,以去除陶瓷介质基板本体表面的油污和灰尘；D、利用磁控溅射工艺使金属沉积在陶瓷介质基板本体表面,形成金属膜层,得到最终的陶瓷介质基板。本发明能够显著提高金属膜层的强度,杜绝金属化膜层起皮、剥落的情况,从而有效提高产品的合格率,且操作简单,基本不会增加额外的成本。(The invention provides a method for metalizing the surface of a ceramic dielectric substrate and the ceramic dielectric substrate, wherein the method comprises the following steps: A. sequentially grinding and/or polishing the original ceramic dielectric substrate body; B. b, preprocessing the ceramic dielectric substrate body after the step A; C. sequentially carrying out ultrasonic cleaning on the sintered ceramic dielectric substrate body by using an acetone solution, alcohol, a slightly acidic cleaning solution and deionized water so as to remove oil stains and dust on the surface of the ceramic dielectric substrate body; D. and depositing metal on the surface of the ceramic dielectric substrate body by utilizing a magnetron sputtering process to form a metal film layer, thereby obtaining the final ceramic dielectric substrate. The method can obviously improve the strength of the metal film layer and prevent the peeling and stripping of the metal film layer, thereby effectively improving the qualification rate of products, and the method is simple to operate and basically does not increase extra cost.)

1. A method for metalizing the surface of a ceramic dielectric substrate is characterized in that: the method comprises the following steps:

A. sequentially grinding and/or polishing the original ceramic dielectric substrate body to obtain a ceramic dielectric substrate body with specified thickness and roughness;

B. and B, preprocessing the ceramic dielectric substrate body after the step A, and the method comprises the following steps:

b1, preparing a non-corrosive reducing solution;

b2, soaking the ceramic dielectric substrate body in a reducing solution for 30-40min, and drying after soaking;

b3, sintering the dried ceramic dielectric substrate body at a high temperature in a sintering furnace at 850 ℃;

C. sequentially carrying out ultrasonic cleaning on the sintered ceramic dielectric substrate body by using an acetone solution, alcohol, a slightly acidic cleaning solution and deionized water so as to remove oil stains and dust on the surface of the ceramic dielectric substrate body;

D. and depositing metal on the surface of the ceramic dielectric substrate body by utilizing a magnetron sputtering process to form a metal film layer, thereby obtaining the final ceramic dielectric substrate.

2. The method of claim 1, wherein the metallization is performed on a surface of a ceramic dielectric substrate, and the method comprises: in the step B1, the reducing solution consists of hydrogen peroxide and ammonia water in a weight ratio of 1: 1.

3. The method of claim 1, wherein the metallization is performed on a surface of a ceramic dielectric substrate, and the method comprises: in the step B3, the sintering furnace includes seven temperature zones, which are:

a first temperature rise region: heating from normal temperature to 550 deg.C for 5 min;

a second temperature rising zone: heating from 550 deg.C to 700 deg.C for 5 min;

a third temperature rising zone: heating from 700 deg.C to 830 deg.C for 5 min;

a fourth temperature rising zone: heating from 830 deg.C to 850 deg.C for 5 min;

and (3) constant-temperature area: maintaining the temperature at 850 deg.C for 10 min;

a first cooling zone: cooling from 850 deg.C to 805 deg.C for 5 min;

a second cooling zone: cooling from 805 deg.C to normal temperature for 10 min.

4. A method according to claim 1, 2 or 3, wherein the method comprises: in the step A, the ceramic dielectric substrate body is obtained by a tape casting method, the ceramic dielectric substrate body is ground to reduce the thickness of the ceramic dielectric substrate body, and when the surface roughness of the ground ceramic dielectric substrate body does not meet the requirement, the surface roughness is reduced by a polishing process.

5. A method according to claim 1, 2 or 3, wherein the method comprises: in the step B2, the drying temperature is set to be 55-65 ℃, and the drying time is 55-65 min.

6. The method of claim 4, wherein the metallization of the surface of the ceramic dielectric substrate comprises: the grinding process comprises the following steps:

a1, placing the ceramic dielectric substrate body on a grinder;

a2, grinding two opposite surfaces of the ceramic medium substrate body by using grinding sand grains in sequence, wherein the minimum thickness of the grinding dust on one surface is 0.08-0.12 mm;

a3, after the thickness of the ceramic dielectric substrate body is ground to the target thickness, cleaning the surface of the substrate by using an acid cleaning solution, and drying.

7. A method according to claim 1, 2 or 3, wherein the method comprises: the ceramic dielectric substrate body comprises an aluminum oxide ceramic substrate or an aluminum nitride ceramic substrate.

8. The ceramic dielectric substrate manufactured by the method for metallizing the surface of a ceramic dielectric substrate according to any one of claims 1 to 7, wherein: the ceramic dielectric substrate comprises a ceramic dielectric substrate body and two metal film layers respectively arranged on two opposite surfaces of the ceramic dielectric substrate body.

Technical Field

The invention relates to a method for metalizing the surface of a ceramic dielectric substrate and the ceramic dielectric substrate.

Background

The microwave element has an irreplaceable function in a communication system all the time, and the application fields are quite wide, including microwave communication, internet application products, consumer electronics products, even national defense, aerospace, aviation and the like. With the continuous upgrade and optimization of electronic products, the application field is deepened gradually, and the requirement of a carrier-printed board of a microwave element is also continuously improved. The traditional printed board, i.e. the PCB board, is mostly made of glass fiber, phenolic resin, PTFE, and the like. These materials are becoming less suitable for use in microwave circuits and microwave components in various aspects such as thermal stress, chemical factors, manufacturing processes, etc. In recent years, ceramic dielectric substrates are applied to the microwave field in a large area and become an irreplaceable main raw material. The 5G communication is popularized and applied on a large scale, and the millimeter wave has the inherent advantages of wide frequency band, short wavelength and high spatial resolution, so that the ceramic dielectric substrate is more required to be used as a microwave transmission base material. The ceramic dielectric substrate has at least the following 7 excellent characteristics: the film has certain mechanical strength, is not easy to warp, and can ensure the flatness of the positive substrate; the material hardness is high, the surface smoothness can be increased by a mechanical processing means, and the high-frequency element and the circuit have high requirements on the surface smoothness; the heat dissipation performance is good, the thermal expansion coefficient is low, and the heat productivity is large when part of high-frequency elements work; the high-frequency performance is stable, and the electrical performance can be ensured; the insulation property is good, the pressure resistance is high, and the safety and the reliability are realized; the water absorption is small, and the environmental suitability is good; the bonding force with metal materials is strong, and the metallization reliability is high.

The deposition of metal film on ceramic dielectric substrate is a key process in the research, development, manufacture and production of microwave elements and microwave circuits. Therefore, the strength of the metallized film layer of the ceramic dielectric substrate becomes an important inspection item of the key process. The strength of the metallized film layer of the substrate can be checked by the bonding force of destructive or non-destructive metal wires (metal strips). And if the bonding force value is lower than the standard requirement or the phenomena of peeling, stripping and the like of the metal film layer occur, judging that the product is unqualified. The ceramic dielectric substrate in the prior art still needs to improve the qualification rate of products.

Conventionally, the method for increasing the metallization strength of the substrate surface comprises the following steps: increasing the sputtering power and increasing the substrate temperature: the sputtering power is improved, so that the metal particles have higher capacity, and the metal particles can be more firmly combined with the crystal lattices of the substrate, thereby achieving the purpose of enhancing the strength of the metallized film layer; according to the law of thermodynamics, the temperature of the substrate is increased, and when metal particles are deposited on the surface of the substrate, the microscopic motion of the metal particles is more violent, so that the aim of enhancing the strength of the metallized film layer can be fulfilled. However, the method for increasing the sputtering power has higher requirements on the magnetron sputtering machine, the equipment cost is high, the method is not easy to realize, the method for increasing the temperature of the substrate has the advantages that the transpiration phenomenon of the adhesion layer can occur under the condition that the temperature of the substrate is increased through tests, the thickness of the adhesion layer is not easy to control, and the two methods have no obvious effect on enhancing the strength of the metalized film layer of the ground or polished medium substrate.

Disclosure of Invention

The invention provides a method for metallizing the surface of a ceramic dielectric substrate and the ceramic dielectric substrate, and the method can obviously improve the strength of a metal film layer and prevent the peeling and spalling of the metallized film layer, thereby effectively improving the qualification rate of products, and the method is simple to operate and basically does not increase extra cost.

The invention is realized by the following technical scheme:

a method for metalizing the surface of a ceramic dielectric substrate comprises the following steps:

A. sequentially grinding and/or polishing the original ceramic dielectric substrate body to obtain a ceramic dielectric substrate body with specified thickness and roughness;

B. and B, preprocessing the ceramic dielectric substrate body after the step A, and the method comprises the following steps:

b1, preparing a non-corrosive reducing solution;

b2, soaking the ceramic dielectric substrate body in a reducing solution for 30-40min, and drying after soaking;

b3, sintering the dried ceramic dielectric substrate body at a high temperature in a sintering furnace at 850 ℃;

C. sequentially carrying out ultrasonic cleaning on the sintered ceramic dielectric substrate body by using an acetone solution, alcohol, a slightly acidic cleaning solution and deionized water so as to remove oil stains and dust on the surface of the ceramic dielectric substrate body;

D. and depositing metal on the surface of the ceramic dielectric substrate body by utilizing a magnetron sputtering process to form a metal film layer, thereby obtaining the final ceramic dielectric substrate.

Further, in the step B1, the reducing solution is composed of hydrogen peroxide and ammonia water in a weight ratio of 1: 1.

Further, in the step B3, the sintering furnace includes seven temperature zones, which are respectively:

a first temperature rise region: heating from normal temperature to 550 deg.C for 5 min;

a second temperature rising zone: heating from 550 deg.C to 700 deg.C for 5 min;

a third temperature rising zone: heating from 700 deg.C to 830 deg.C for 5 min;

a fourth temperature rising zone: heating from 830 deg.C to 850 deg.C for 5 min;

and (3) constant-temperature area: maintaining the temperature at 850 deg.C for 10 min;

a first cooling zone: cooling from 850 deg.C to 805 deg.C for 5 min;

a second cooling zone: cooling from 805 deg.C to normal temperature for 10 min.

Further, in the step a, the ceramic dielectric substrate body is obtained by tape casting, the ceramic dielectric substrate body is subjected to a grinding process to reduce the thickness of the ceramic dielectric substrate body, and when the surface roughness of the ground ceramic dielectric substrate body does not meet the requirement, the surface roughness is reduced by a polishing process.

Further, in the step B2, the drying temperature is set to be 55-65 ℃, and the drying time is 55-65 min.

Further, the grinding process comprises the following steps:

a1, placing the ceramic dielectric substrate body on a grinder;

a2, grinding two opposite surfaces of the ceramic medium substrate body by using grinding sand grains in sequence, wherein the minimum thickness of the grinding dust on one surface is 0.08-0.12 mm;

a3, after the thickness of the ceramic dielectric substrate body is ground to the target thickness, cleaning the surface of the substrate by using an acid cleaning solution, and drying.

Further, the ceramic dielectric substrate body comprises an aluminum oxide ceramic substrate or an aluminum nitride ceramic substrate.

The invention is also realized by the following technical scheme:

the ceramic dielectric substrate manufactured by the method for metalizing the surface of the ceramic dielectric substrate comprises a ceramic dielectric substrate body and two metal film layers respectively arranged on two opposite surfaces of the ceramic dielectric substrate body.

The invention has the following beneficial effects:

1. the invention firstly grinds and/or polishes the original ceramic dielectric substrate to obtain the ceramic dielectric substrate with the specified thickness and roughness, then pretreats the ceramic dielectric substrate, and mainly comprises the steps of soaking the ceramic dielectric substrate by using reducing solution and sintering the ceramic dielectric substrate at a high temperature of 850 ℃, cleaning the ceramic dielectric substrate after the pretreatment, forming a metal film layer by using a magnetron sputtering process after the cleaning is finished, wherein the surface of the ground or polished ceramic dielectric substrate has residual pickling solution and magnetic powder particles, but the cleaning step can not remove the residual pickling solution and the magnetic powder particles, if the magnetron sputtering is directly carried out, the formed metal film layer is easy to peel and peel off, and the residual substances can be completely removed by soaking the reducing solution and sintering the ceramic dielectric substrate at the high temperature, so that the surface of the ceramic dielectric substrate is more active, and the strength of the metal film layer is enhanced, the bonding force of the metal film layer is improved, so that the peeling and stripping of the metallized film layer are avoided, the qualification rate of products is effectively improved, the operation is simple, and the additional cost is basically not increased; the ceramic dielectric substrate is soaked in the reducing solution for 30-40min, the residues can be effectively dissolved, the reducing solution is not corrosive, the ceramic dielectric substrate cannot be damaged, the high-temperature sintering is carried out by using a 850 ℃ sintering furnace, the substances remained on the surface of the ceramic dielectric substrate can be evaporated, the temperature of 850 ℃ is slightly lower than the low-temperature co-firing temperature of the ceramic, and the structural damage to the ceramic dielectric substrate cannot be caused.

2. When the ceramic dielectric substrate is sintered at high temperature, seven temperature zones are arranged to form a specific temperature curve, and the curve can prevent the stress from occurring in the ceramic dielectric substrate, so that the ceramic dielectric substrate is prevented from being damaged.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings.

FIG. 1 is a flow chart of the present invention.

FIG. 2 is a temperature profile of the high temperature sintering of the present invention.

Detailed Description

The ceramic dielectric substrate comprises a ceramic dielectric substrate body and two metal film layers respectively arranged on the upper surface and the lower surface of the ceramic dielectric substrate body. As shown in fig. 1, the method for metallizing the surface of the ceramic dielectric substrate comprises the following steps:

A. sequentially grinding and/or polishing the original ceramic dielectric substrate body to obtain a ceramic dielectric substrate body with specified thickness and roughness;

the ceramic dielectric substrate body is obtained by a tape casting method, and is generally made of an alumina ceramic substrate or an aluminum nitride ceramic substrate, in this embodiment, the alumina ceramic substrate is taken as an example; the minimum thickness of a ceramic dielectric substrate body cast from the alumina ceramic substrate is about 0.3mm, but for high-frequency printing and microwave elements, the design requirement of the ceramic dielectric substrate body is that the thickness of the ceramic dielectric substrate body is less than 0.254mm, and the thickness of a part of the ceramic dielectric substrate body is even less than or equal to 0.127mm, so that the ceramic dielectric substrate body can be obtained only by grinding the ceramic dielectric substrate body; on the other hand, for high-frequency printing and microwave elements, the requirement on the roughness of the surface of the ceramic dielectric substrate is high, and when the surface roughness of the ground ceramic dielectric substrate body does not meet the requirement, the surface roughness needs to be reduced through a polishing process; however, the surface of the ceramic dielectric substrate body after grinding or polishing has residual pickling solution and magnetic powder small particles, so that the adhesive force of the metal film layer does not reach the standard, and the metal film layer is easy to peel off, so that the ceramic dielectric substrate body needs to be pretreated;

wherein, the grinding process comprises the following steps:

a1, placing the ceramic dielectric substrate body on a grinder;

a2, grinding two opposite surfaces of the ceramic medium substrate body by using grinding sand grains in sequence, wherein the minimum thickness of the grinding dust on one surface is 0.08-0.12 mm;

a3, after the thickness of the ceramic dielectric substrate body is ground to a target thickness, cleaning the surface of the substrate by using an acid cleaning solution, and drying;

B. and B, preprocessing the ceramic dielectric substrate body after the step A, and the method comprises the following steps:

b1, preparing a non-corrosive reducing solution, wherein the reducing solution consists of hydrogen peroxide, ammonia water, a slow release agent and an additive in a weight ratio of 1:1:1: 1; the ammonia water can promote the activity of hydrogen peroxide, so that the optimal soaking time of the ceramic dielectric substrate body is shortened; the slow release agent can reduce the decomposition speed of hydrogen peroxide, so that the reducibility is easy to improve and the stability is easy to improve;

b2, soaking the ceramic dielectric substrate body in the reducing solution for 30-40min, and drying after soaking, wherein the drying temperature is set to 55-65 ℃, and the drying time is 55-65 min; wherein, the soaking time is set as 35min, the drying temperature is set as 60 ℃, and the drying time is set as 60min, so that the effect is best;

b3, sintering the dried ceramic dielectric substrate body at a high temperature in a sintering furnace at 850 ℃;

as shown in fig. 2, the sintering furnace includes seven temperature zones, respectively:

a first temperature rise region: heating from normal temperature to 550 deg.C for 5 min;

a second temperature rising zone: heating from 550 deg.C to 700 deg.C for 5 min;

a third temperature rising zone: heating from 700 deg.C to 830 deg.C for 5 min;

a fourth temperature rising zone: heating from 830 deg.C to 850 deg.C for 5 min;

and (3) constant-temperature area: maintaining the temperature at 850 deg.C for 10 min;

a first cooling zone: cooling from 850 deg.C to 805 deg.C for 5 min;

a second cooling zone: cooling from 805 deg.C to normal temperature for 10 min;

C. sequentially carrying out ultrasonic cleaning on the sintered ceramic dielectric substrate body by using an acetone solution, alcohol, a slightly acidic cleaning solution and deionized water so as to remove oil stains and dust on the surface of the ceramic dielectric substrate body;

D. and depositing metal on the surface of the ceramic dielectric substrate body by utilizing a magnetron sputtering process to form a metal film layer, thereby obtaining the final ceramic dielectric substrate. The magnetron sputtering process is the prior art.

Table 1 shows the comparison of the bonding force values of the metal film layers and the film layer appearance of the randomly sampled 6 ceramic dielectric substrate samples not using the present invention and the 6 ceramic mechanical substrate samples using the present invention:

TABLE 1

Therefore, the ceramic dielectric substrate has the advantages that the bonding force value of the metal film layer is greatly improved, and the appearance of the film layer has no peeling condition.

The above description is only a preferred embodiment of the present invention, and therefore should not be taken as limiting the scope of the invention, which is defined by the appended claims and their equivalents and modifications within the scope of the description.