阅读说明：本技术 一种覆铜板压制方法 (Copper-clad plate pressing method ) 是由 俞金发 朱良科 林士兵 于 2021-08-17 设计创作，主要内容包括：本发明涉及一种覆铜板压制方法,包括基板处理,导热胶配制、板材组合、热压成型、裁切步骤。其中通过对金属基板进行打磨预处理,调整导热胶材质的方法提高基板与导热胶之间的结合力,提高覆铜板的剥离强度,减少次品率；同时对热压成型步骤的方法进行优化,通过多次的压力及温度变化充分释放覆铜板生产过程中产生的内应力,有效减少了覆铜板的翘曲,为后续的高品质PCB板生产提供良好基础。(The invention relates to a pressing method of a copper-clad plate, which comprises the steps of substrate treatment, heat-conducting glue preparation, plate combination, hot-press forming and cutting. The method for adjusting the material quality of the heat-conducting adhesive improves the binding force between the substrate and the heat-conducting adhesive, improves the peeling strength of the copper-clad plate and reduces the defective rate by polishing the metal substrate; meanwhile, the hot press forming method is optimized, internal stress generated in the production process of the copper clad plate is fully released through repeated pressure and temperature changes, warping of the copper clad plate is effectively reduced, and a good foundation is provided for subsequent high-quality PCB production.)

1. A pressing method of a copper-clad plate is characterized by comprising the following steps: the method comprises the following steps:

substrate treatment: degreasing and polishing a metal substrate of the copper-clad plate to improve the roughness of the surface of the metal substrate;

preparing a heat-conducting adhesive: mixing and uniformly stirring the modified polyphenyl ether resin and the heat-conducting filler, coating the mixture on base cloth, and removing the base cloth after baking and curing to obtain a heat-conducting adhesive film;

plate combination: cutting the substrate, the copper foil and the heat-conducting adhesive film to corresponding sizes, and stacking in sequence;

hot-press molding: placing the stacked combination in the previous step into a vacuum press, slowly heating, continuously increasing the pressure, keeping the pressure unchanged after reaching the specified pressure and temperature, slowly reducing the temperature, reducing the pressure after returning to the initial temperature, raising the pressure again after reducing the pressure to the initial pressure, and returning to the initial pressure value, thus completing the hot press molding;

cutting: and cutting the copper-clad plate subjected to hot press molding according to requirements to obtain a finished product of the copper-clad plate.

2. The copper-clad plate pressing method according to claim 1, characterized in that: in the step of treating the substrate, hot alkali liquor with the concentration of 15-25% is used for removing oil from the substrate.

3. The copper-clad plate pressing method according to claim 2, characterized in that: in the step of processing the substrate, a 500-800-mesh grinding wheel is used for roughening the surface of the substrate during grinding.

4. The copper-clad plate pressing method according to claim 1, characterized in that: in the step of preparing the heat-conducting glue, the heat-conducting filler is a nano inorganic non-metal heat-conducting filler.

5. The copper-clad plate pressing method according to claim 4, characterized in that: in the step of preparing the heat-conducting glue, the mass ratio of the modified polyphenylene ether resin to the heat-conducting filler is 1: 5-7.

6. The copper-clad plate pressing method according to claim 1, characterized in that: in the plate combination step, the copper foil, the heat-conducting adhesive film and the metal substrate are combined in sequence.

7. The copper-clad plate pressing method according to claim 1, characterized in that: in the hot-press molding step, the temperature variation range is 80-260 ℃.

8. The copper-clad plate pressing method according to claim 7, characterized in that: in the hot-press molding step, the pressure variation range is 1-6 Mpa.

9. The copper-clad plate pressing method according to claim 7, characterized in that: in the hot press molding step, the vacuum time is kept for at least 40 min.

Technical Field

The invention belongs to the field of copper-clad plate preparation, and particularly relates to a copper-clad plate pressing method.

Background

With the continuous development of social productivity, more and more electronic products appear in daily life, a basic framework for producing the electronic and electric products is a PCB (printed circuit board), and a substrate of the PCB is a copper-clad plate. And drilling, electroplating, transferring circuit patterns, etching, solder mask and the like on the copper-clad plate to prepare the PCB.

However, with the development of electronics, in order to achieve higher performance indexes, the requirements on the smoothness and the dimensional stability of the PCB are more and more strict, and the copper-clad plate must have high smoothness and dimensional stability, but most of the existing copper-clad plate production technologies adopt the combination of a resin adhesive film and a metal substrate and are subjected to hot press molding, so that severe internal stress is generated in the production process, the copper-clad plate material is warped, the dimensional stability is affected, and the welding difficulty of subsequent products is increased; the influence on the accuracy of the components is great, and higher performance indexes are difficult to achieve.

In order to reduce the internal stress during the production of the copper-clad plate, the manufacturing material of the copper-clad plate needs to be improved, so that the bonding strength between the adhesive film and the substrate is improved, and the hot-pressing process needs to be improved, so that the internal stress generated after the temperature and pressure change is fully reduced. Therefore, a novel copper-clad plate pressing method is provided to improve the production qualification rate of the copper-clad plate.

Disclosure of Invention

The invention aims to provide a copper-clad plate pressing method, which solves the problem that the copper-clad plate is easy to generate internal stress during production.

The technical scheme adopted by the invention for solving the technical problems is as follows: a pressing method of a copper-clad plate comprises the following steps:

substrate treatment: degreasing and polishing a metal substrate of the copper-clad plate to improve the roughness of the surface of the metal substrate;

preparing heat-conducting glue: mixing and uniformly stirring the modified polyphenyl ether resin and the heat-conducting filler, coating the mixture on base cloth, and removing the base cloth after baking and curing to obtain a heat-conducting adhesive film;

plate combination: cutting the substrate, the copper foil and the heat-conducting adhesive film to corresponding sizes, and stacking in sequence;

hot-press molding: placing the stacked combination in the previous step into a vacuum press, slowly heating, continuously increasing the pressure, keeping the pressure unchanged after reaching the specified pressure and temperature, slowly reducing the temperature, reducing the pressure after returning to the initial temperature, raising the pressure again after reducing the pressure to the initial pressure, and returning to the initial pressure value, thus completing the hot press molding;

cutting: and cutting the copper-clad plate subjected to hot press molding according to requirements to obtain a finished product of the copper-clad plate.

Preferably, in the substrate treating step, the substrate is degreased using a hot alkali solution having a concentration of 15 to 25%.

Preferably, in the step of processing the substrate, a grinding wheel with 500-800 meshes is used for roughening the surface of the substrate during grinding.

Preferably, in the step of preparing the heat-conducting adhesive, the heat-conducting filler is a nano inorganic non-metallic heat-conducting filler.

Preferably, in the step of preparing the heat-conducting glue, the mass ratio of the modified polyphenylene ether resin to the heat-conducting filler is 1:5-7

Preferably, in the plate combining step, the copper foil, the heat-conducting adhesive film and the metal substrate are combined in sequence.

Preferably, in the hot press molding step, the temperature variation range is 80 to 260 ℃.

Preferably, in the hot press molding step, the pressure variation range is 1 to 6 Mpa.

Preferably, in the hot press molding step, the vacuum time is maintained for at least 40 min.

The invention has the following beneficial effects: the adhesive film is prepared from the modified polyphenyl ether resin, and the modified polyphenyl ether resin not only has good dielectric capacity, but also has excellent dimensional stability, has low melt viscosity at high temperature, and is not easy to generate internal stress in the environment with temperature and pressure change. In the hot press forming process, the pressure and the temperature are changed for many times in a vacuum environment, the internal stress of the plate is fully released, the internal stress of the plate is fully reduced, and the plate is kept flat.

Detailed Description

Example 1

Substrate treatment: selecting an iron-based base plate as a metal substrate, degreasing by using a 15% sodium hydroxide solution at 50 ℃, cleaning, polishing the surface by using a 500-mesh grinding wheel, roughening, and drying for later use;

preparing heat-conducting glue: mixing and uniformly stirring modified polyphenyl ether resin and inorganic nonmetal heat-conducting filler, coating the mixture on base cloth, and removing the base cloth after baking and curing to obtain a heat-conducting adhesive film, wherein the ratio of the modified polyphenyl ether resin to the inorganic nonmetal heat-conducting filler is 1: 5;

plate combination: cutting the substrate, the copper foil and the heat-conducting adhesive film to corresponding sizes, and stacking in sequence;

hot-press molding: putting the stacked combination in the previous step into a vacuum press, pressurizing to 1Mpa, slowly heating to 80 ℃, setting specific pressure and temperature change as shown in table 1, and finally completing hot press molding by recovering initial values of the temperature and the pressure;

cutting: and cutting the copper-clad plate subjected to hot press molding according to requirements to obtain a finished product of the copper-clad plate.

TABLE 1

Example 2

Substrate treatment: selecting an aluminum substrate plate as a metal substrate, cleaning, polishing the surface by using a 800-mesh grinding wheel, roughening, drying and standing for later use;

preparing heat-conducting glue: mixing and uniformly stirring modified polyphenyl ether resin and inorganic nonmetal heat-conducting filler, coating the mixture on base cloth, and removing the base cloth after baking and curing to obtain a heat-conducting adhesive film, wherein the ratio of the modified polyphenyl ether resin to the inorganic nonmetal heat-conducting filler is 1: 7;

plate combination: cutting the substrate, the copper foil and the heat-conducting adhesive film to corresponding sizes, and stacking in sequence;

hot-press molding: putting the stacked combination in the previous step into a vacuum press, pressurizing to 1Mpa, slowly heating to 80 ℃, setting specific pressure and temperature change as shown in table 2, and finally completing hot press molding by recovering the initial values of the temperature and the pressure;

cutting: and cutting the copper-clad plate subjected to hot press molding according to requirements to obtain a finished product of the copper-clad plate.

TABLE 2

Comparative example 1

Substrate treatment: selecting an iron-based base plate as a metal substrate, cleaning, drying and standing for later use;

preparing heat-conducting glue: mixing and uniformly stirring the modified polyphenylene oxide resin and the inorganic nonmetal heat-conducting filler, coating the mixture on base cloth, baking and curing the mixture, and removing the base cloth to obtain a heat-conducting adhesive film;

plate combination: cutting the substrate, the copper foil and the heat-conducting adhesive film to corresponding sizes, and stacking in sequence;

hot-press molding: putting the stacked combination in the previous step into a vacuum press for one-time hot press molding;

cutting: and cutting the copper-clad plate subjected to hot press molding according to requirements to obtain a finished product of the copper-clad plate.

The results of the performance index tests performed on the samples of each example and comparative example are shown in Table 3

TABLE 3

Sample (I)	Peel strength (N/mm)	Warping degree (%)
			Example 1	2.6	0.18
Example 2	3	0.13
			Comparative example 1	1.05	0.57

The final performance detection indexes show that the bonding force between the adhesive film and the substrate can be effectively improved by improving the formula of the heat-conducting adhesive film and pretreating the substrate, and the peel strength of the adhesive film and the substrate is improved by 2-3 times compared with that of the untreated substrate; meanwhile, the warping degree of the copper-clad plate is greatly reduced by pressing for multiple times under the condition of pressure and temperature change, the warping degree is only about one third of that of a product formed by hot pressing once, and the copper-clad plate pressing method can effectively improve the performance of the copper-clad plate and the product percent of pass.

In summary, although the present invention has been described with reference to the preferred embodiments, the above-described preferred embodiments are not intended to limit the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, therefore, the scope of the present invention shall be determined by the appended claims.