阅读说明：本技术 一种铜箔及其加工方法 (Copper foil and processing method thereof ) 是由 顾亮 李帅 闫瑞刚 周建华 顾凯越 于 2021-09-24 设计创作，主要内容包括：本发明提供一种铜箔及其加工方法。本发明的铜箔加工方法,包括：对初始铜箔依次进行粗化处理、第一固化处理、第二固化处理和第三固化处理,得到所述铜箔；其中,所述第一固化处理的电流密度小于所述第二固化处理的电流密度,所述第二固化处理的电流密度小于等于所述第三固化处理的电流密度；所述第二固化处理和/或所述第三固化处理的电流密度为50～80A/dm～(2)。由于在第一固化处理的基础上,又进行了两次高电流密度的固化处理,能够形成具有牢固镀层的铜箔,进而使该铜箔在使用过程中,几乎不会产生铜粉,可以用于制备多层精细线路板。(The invention provides a copper foil and a processing method thereof. The copper foil processing method of the invention comprises the following steps: sequentially carrying out roughening treatment, first curing treatment, second curing treatment and third curing treatment on the initial copper foil to obtain the copper foil; wherein the current density of the first curing process is less than the current density of the second curing process, which is less than or equal to the current density of the third curing process; the current density of the second curing treatment and/or the third curing treatment is 50-80A/dm 2 . Because the first curing treatment is carried out and two times of high-current-density curing treatment are carried out, the copper foil with a firm plating layer can be formed, and the copper foil is further used in the using processCopper powder is hardly generated, and the method can be used for preparing a multilayer fine circuit board.)

1. A method for processing a copper foil is characterized by comprising the following steps: sequentially carrying out roughening treatment, first curing treatment, second curing treatment and third curing treatment on the initial copper foil to obtain the copper foil;

wherein the current density of the first curing process is less than the current density of the second curing process, which is less than or equal to the current density of the third curing process;

the coarsening treatment comprises the following steps: electroplating the initial copper foil by using a roughening solution to obtain a roughened copper foil;

in the coarsening treatment: the current density is 20-70A/dm²The temperature is 15-40 ℃;

in the roughening solution: the concentration of sulfuric acid is 50-200 g/L, the concentration of copper ions is 5-20 g/L, and the concentration of chloride ions is 10-40 mg/L;

in the first curing treatment: the current density is 10-40A/dm²The temperature is 40-50 ℃;

in the second curing treatment: the current density is 50-80A/dm²The temperature is 40-50 ℃;

in the third curing treatment: the current density is 50-80A/dm²The temperature is 40-50 ℃.

2. The method of claim 1, wherein the first curing process comprises: electroplating the roughened copper foil by using a first curing liquid to obtain a first cured copper foil;

the second curing process includes: electroplating the first solidified copper foil by using a second solidified liquid to obtain a second solidified copper foil;

the third curing process includes: electroplating the second solidified copper foil by using a third solidified liquid to obtain the copper foil;

the concentration of copper ions in the first curing liquid is less than that of copper ions in the second curing liquid, and the concentration of copper ions in the second curing liquid is less than or equal to that of copper ions in the third curing liquid.

3. The method for processing a copper foil according to claim 2, wherein in the first curing liquid: the concentration of copper ions is 30-50 g/L, and the concentration of sulfuric acid is 50-150 g/L; and/or the presence of a gas in the gas,

in the second curing liquid: the concentration of copper ions is 60-90 g/L, and the concentration of sulfuric acid is 50-150 g/L; and/or the presence of a gas in the gas,

in the third curing liquid: the concentration of copper ions is 60-90 g/L, and the concentration of sulfuric acid is 50-150 g/L.

4. The method of processing a copper foil according to claim 2, wherein in the first curing treatment: the current density is 20-40A/dm²The temperature is 40-45 ℃; in the first curing liquid: the concentration of copper ions is 40-50 g/L, and the concentration of sulfuric acid is 80-150 g/L; and/or the presence of a gas in the gas,

in the second curing treatment: the current density is 60-80A/dm²The temperature is 40-45 ℃; in the second curing liquid: the concentration of copper ions is 70-90 g/L, and the concentration of sulfuric acid is 80-150 g/L; and/or the presence of a gas in the gas,

in the third curing treatment: the current density is 60-80A/dm²The temperature is 40-45 ℃; in the third curing liquid: the concentration of copper ions is 70-90 g/L, and the concentration of sulfuric acid is 80-150 g/L.

5. The method for processing copper foil according to claim 1 or 4, further comprising an acid pickling treatment before the roughening treatment;

the temperature of the acid washing treatment is 30-40 ℃;

in the pickling solution used for the pickling treatment: the concentration of sulfuric acid is 110-190 g/L, and the concentration of copper ions is 20-30 g/L.

6. The method of claim 5, further comprising a corrosion prevention treatment after the third curing treatment;

in the corrosion prevention treatment: the current density is 3-8A/dm²The temperature is 30-60 ℃;

in the corrosion prevention solution used for the corrosion prevention treatment: the concentration of zinc ions is 2-20 g/L, the concentration of potassium pyrophosphate is 70-350 g/L, and the pH value of the anti-corrosion solution is 9.0-10.0.

7. The method of processing a copper foil according to claim 6, further comprising an oxidation preventing treatment after the corrosion preventing treatment;

in the oxidation prevention treatment: the current density is 5-8A/dm²The temperature is 30-40 ℃;

among the oxidation preventing agents used for the oxidation preventing treatment: the concentration of hexavalent chromium ions is 2-7 g/L, and the pH value of the antioxidant is 10.0-12.0.

8. A copper foil processed by the method for processing a copper foil according to any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of electronic copper foil manufacturing, in particular to a copper foil and a processing method thereof.

Background

With the development of electronic information technology, the usage of multi-layer fine circuit boards in high-precision miniaturized electronic products is increasing day by day. At present, copper foil is commonly used for pressing a circuit board, however, when the circuit board is formed by pressing the copper foil, the copper foil can fall off copper powder, the copper powder after falling off is easily mixed in a base material, and the problems of incomplete etching and base material pollution can occur, particularly when the copper foil is used for pressing a multi-layer fine circuit board, the fallen copper powder can also easily cause short circuit of the multi-layer fine circuit board, and the product quality of the circuit board is seriously influenced.

Disclosure of Invention

The invention provides a processing method of copper foil, which can obtain copper foil not easy to generate copper powder in use.

The invention provides a copper foil, the surface coating of which is firmer and copper powder is not easy to generate in the using process.

The invention provides a processing method of a copper foil, which comprises the following steps: sequentially carrying out roughening treatment, first curing treatment, second curing treatment and third curing treatment on the initial copper foil to obtain the copper foil;

wherein the current density of the first curing process is less than the current density of the second curing process, which is less than or equal to the current density of the third curing process;

the current density of the second curing treatment and/or the third curing treatment is 50-80A/dm²。

The processing method as described above, wherein the roughening treatment includes: electroplating the initial copper foil by using a roughening solution to obtain a roughened copper foil;

in the coarsening treatment: the current density is 20-70A/dm²The temperature is 15-40 ℃;

in the roughening solution: the concentration of sulfuric acid is 50-200 g/L, the concentration of copper ions is 5-20 g/L, and the concentration of chloride ions is 10-40 mg/L.

The processing method described above, wherein in the first curing process: the current density is 10-40A/dm²The temperature is 40-50 ℃; and/or the presence of a gas in the gas,

in the second curing treatment: the temperature is 40-50 ℃; and/or the presence of a gas in the gas,

in the third curing treatment: the temperature is 40-50 ℃.

The processing method as described above, wherein the first curing process includes: electroplating the roughened copper foil by using a first curing liquid to obtain a first cured copper foil;

the second curing process includes: electroplating the first solidified copper foil by using a second solidified liquid to obtain a second solidified copper foil;

the third curing process includes: electroplating the second solidified copper foil by using a third solidified liquid to obtain the copper foil;

the concentration of copper ions in the first curing liquid is less than that of copper ions in the second curing liquid, and the concentration of copper ions in the second curing liquid is less than or equal to that of copper ions in the third curing liquid.

The processing method described above, wherein, in the first curing liquid: the concentration of copper ions is 30-50 g/L, and the concentration of sulfuric acid is 50-150 g/L; and/or the presence of a gas in the gas,

in the second curing liquid: the concentration of copper ions is 60-90 g/L, and the concentration of sulfuric acid is 50-150 g/L; and/or the presence of a gas in the gas,

in the third curing liquid: the concentration of copper ions is 60-90 g/L, and the concentration of sulfuric acid is 50-150 g/L.

The processing method described above, wherein in the first curing process: the current density is 20-40A/dm²The temperature is 40-45 ℃; in the first curing liquid: the concentration of copper ions is 40-50 g/L, and the concentration of sulfuric acid is 80-150 g/L; and/or the presence of a gas in the gas,

in the second curing treatment: the current density is 60-80A/dm²The temperature is 40-45 DEG C(ii) a In the second curing liquid: the concentration of copper ions is 70-90 g/L, and the concentration of sulfuric acid is 80-150 g/L; and/or the presence of a gas in the gas,

in the third curing treatment: the current density is 60-80A/dm²The temperature is 40-45 ℃; in the third curing liquid: the concentration of copper ions is 70-90 g/L, and the concentration of sulfuric acid is 80-150 g/L.

The processing method as described above, further comprising an acid washing treatment before the roughening treatment;

the temperature of the acid washing treatment is 30-40 ℃;

in the pickling solution used for the pickling treatment: the concentration of sulfuric acid is 110-190 g/L, and the concentration of copper ions is 20-30 g/L.

The processing method as described above, wherein an anti-corrosion treatment is further included after the third curing treatment;

in the corrosion prevention treatment: the current density is 3-8A/dm²The temperature is 30-60 ℃;

in the corrosion prevention solution used for the corrosion prevention treatment: the concentration of zinc ions is 2-20 g/L, the concentration of potassium pyrophosphate is 70-350 g/L, and the pH value of the anti-corrosion solution is 9.0-10.0.

The machining method as described above, further comprising an oxidation preventing treatment after the corrosion preventing treatment;

in the oxidation prevention treatment: the current density is 5-8A/dm²The temperature is 30-40 ℃;

among the oxidation preventing agents used for the oxidation preventing treatment: the concentration of hexavalent chromium ions is 2-7 g/L, and the pH value of the antioxidant is 10.0-12.0.

The invention also provides a copper foil which is processed by the processing method.

The invention provides a processing method of a copper foil, which is characterized in that a second curing treatment and a third curing treatment are carried out on the basis of a first curing treatment, wherein the current density of the second curing treatment is greater than that of the first curing treatment, the current density of the third curing treatment is greater than or equal to that of the second curing treatment, and the current density of the second curing treatment and/or the third curing treatment is 50-50 ~80A/dm²Because the first curing treatment is carried out, and the curing treatment with high current density is carried out twice, the copper foil with a firm plating layer can be formed, and the copper foil can hardly generate copper powder in the using process and can be used for preparing a multi-layer fine circuit board.

The invention provides a copper foil, which has firm surface coating, hardly generates copper powder in the using process and can be used for preparing a high-quality multi-layer fine circuit board.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the related art, the drawings used in the description of the embodiments of the present invention or the related art are briefly introduced below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is an apparatus for processing copper foil in accordance with some embodiments of the present invention;

FIG. 2 is a surface Scanning Electron Microscope (SEM) image of a copper foil produced in example 1 of the present invention;

FIG. 3 is an SEM photograph of a copper foil produced in example 2 of the present invention;

FIG. 4 is a surface SEM photograph of a copper foil produced in comparative example 1 of the present invention;

FIG. 5 is a surface SEM photograph of a copper foil produced in comparative example 2 of the present invention;

fig. 6 is a surface SEM image of the copper foil manufactured in comparative example 3 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The first aspect of the present invention provides a method for processing a copper foil, comprising: sequentially carrying out roughening treatment, first curing treatment, second curing treatment and third curing treatment on the initial copper foil to obtain a copper foil;

wherein the current density of the first curing treatment is less than that of the second curing treatment, and the current density of the second curing treatment is less than or equal to that of the third curing treatment;

the current density of the second curing treatment and/or the third curing treatment is 50-80A/dm²。

The copper foil processing method of the invention comprises the steps of firstly, roughening the initial copper foil to improve the surface roughness of the initial copper foil, so that the initial copper foil is easy to process; then, carrying out first curing treatment on the coarsened initial copper foil to form a plating layer on the surface of the coarsened initial copper foil, wherein the plating layer has a plurality of fine particles; then, carrying out second curing treatment on the initial copper foil subjected to the first curing treatment, wherein fine particles in the plating layer can be finer due to the fact that the current density of the second curing treatment is larger than that of the first curing treatment, and the firmness of the plating layer is improved; and finally, carrying out third curing treatment on the initial copper foil subjected to the second curing treatment, wherein the current density of the third curing treatment is more than or equal to that of the second curing treatment, so that fine particles in the plating layer can be further refined, the firmness of the plating layer is further improved, and the copper foil is not easy to generate copper powder in the using process.

In the present invention, the current density due to the second curing treatment and/or the third curing treatment is 50 to 80A/dm²Under the current density, the energy consumption can be saved, fine particles in the fine coating can be maximized, the firmness of the coating is further improved, and the copper foil is not easy to generate copper powder in the using process.

The initial copper foil is an electrolytic copper foil, and the initial copper foil is not particularly limited in the invention and can be selected from initial copper foils commonly used in the field. In the present invention, the initial copper foil has a thickness of 12 to 40 μm.

The roughening treatment in the present invention is not particularly limited, and the initial copper foil may be roughened by a roughening treatment method commonly used in the art.

The present invention is also not particularly limited to the first curing treatment, the second curing treatment and the third curing treatment, as long as the current density of the first curing treatment is lower than the current density of the second curing treatment, and the current density of the second curing treatment is equal to or lower than the current density of the third curing treatment.

According to the processing method of the copper foil, the copper foil with a firm plating layer can be formed by performing two times of high-current-density curing treatment on the basis of the first curing treatment, so that copper powder is hardly generated in the using process of the copper foil, and the copper foil can be used for preparing a multi-layer fine circuit board.

In some embodiments of the present invention, in order to improve the effect of the roughening treatment, which makes the initial copper foil easier to process, the roughening treatment includes: electroplating the initial copper foil by using the roughening solution to obtain a roughened copper foil;

in the coarsening treatment: the current density is 20-70A/dm²The temperature is 15-40 ℃;

in the roughening solution: the concentration of sulfuric acid is 50-200 g/L, the concentration of copper ions is 5-20 g/L, and the concentration of chloride ions is 10-40 mg/L.

In some embodiments of the invention, in the first curing process: the current density is 10-40A/dm²The temperature is 40-50 ℃; and/or the presence of a gas in the gas,

in the second curing treatment: the temperature is 40-50 ℃; and/or the presence of a gas in the gas,

in the third curing treatment: the temperature is 40-50 ℃.

Specifically, when the current density and temperature of the first curing treatment satisfy the above conditions, and the temperatures of the second curing treatment and the third curing treatment satisfy the above conditions, a copper foil with better surface plating firmness can be obtained, and the copper foil hardly generates copper powder in the use process, and can be used for preparing a multilayer fine circuit board.

In some embodiments of the invention, the first curing process comprises: electroplating the roughened copper foil by using a first curing liquid to obtain a first cured copper foil;

the second curing process includes: electroplating the first solidified copper foil by using the second solidified liquid to obtain a second solidified copper foil;

the third curing process includes: electroplating the second solidified copper foil by using the third solidified liquid to obtain a copper foil;

the concentration of copper ions in the first curing liquid is less than that of copper ions in the second curing liquid, and the concentration of copper ions in the second curing liquid is less than or equal to that of copper ions in the third curing liquid.

In the invention, the initial copper foil is subjected to roughening treatment to obtain a roughened copper foil; then electroplating the roughened copper foil by using a first curing liquid to form a plating layer with fine particles on the surface of the roughened copper foil to obtain a first cured copper foil; then, electroplating the first solidified copper foil by using a second solidified liquid to obtain a second solidified copper foil, wherein fine particles in the surface coating of the second solidified copper foil are finer than fine particles in the surface coating of the first solidified copper foil because the concentration of copper ions in the second solidified liquid is greater than that of copper ions in the first solidified liquid; and finally, electroplating the second solidified copper foil by using a third solidified liquid to obtain a third solidified copper foil, wherein the concentration of copper ions in the third solidified liquid is more than or equal to that of the copper ions in the second solidified liquid, so that fine particles in a surface coating of the third solidified copper foil are finer than those on the surface of the second solidified copper foil, the firmness of the coating can be further improved, and the copper foil is less prone to generating copper powder in the using process.

The present invention does not particularly limit the composition of the first curing solution, the second curing solution and the third curing solution, as long as the concentration of copper ions in the first curing solution is less than the concentration of copper ions in the second curing solution, and the concentration of copper ions in the second curing solution is equal to or less than the concentration of copper ions in the third curing solution.

In some embodiments of the invention, in the first curing liquid: the concentration of copper ions is 30-50 g/L, and the concentration of sulfuric acid is 50-150 g/L; and/or the presence of a gas in the gas,

in the second curing liquid: the concentration of copper ions is 60-90 g/L, and the concentration of sulfuric acid is 50-150 g/L; and/or the presence of a gas in the gas,

in the third curing liquid: the concentration of copper ions is 60-90 g/L, and the concentration of sulfuric acid is 50-150 g/L.

Further, in order to make the surface plating layer of the formed copper foil finer and firmer, make the copper foil less prone to generate copper powder during use, and improve the application range of the copper foil, in some embodiments of the present invention, in the first curing treatment: the current density is 20-40A/dm²The temperature is 40-45 ℃; in the first curing liquid: the concentration of copper ions is 40-50 g/L, and the concentration of sulfuric acid is 80-150 g/L; and/or the presence of a gas in the gas,

in the second curing treatment: the current density is 60-80A/dm²The temperature is 40-45 ℃; in the second curing liquid: the concentration of copper ions is 70-90 g/L, and the concentration of sulfuric acid is 80-150 g/L; and/or the presence of a gas in the gas,

in the third curing treatment: the current density is 60-80A/dm²The temperature is 40-45 ℃; in the third curing liquid: the concentration of copper ions is 70-90 g/L, and the concentration of sulfuric acid is 80-150 g/L.

In some embodiments of the present invention, the roughening treatment further comprises an acid washing treatment;

the temperature of the acid washing treatment is 30-40 ℃;

in the pickling solution for pickling treatment: the concentration of sulfuric acid is 110-190 g/L, and the concentration of copper ions is 20-30 g/L.

According to the invention, before the roughening treatment, the acid pickling solution with the proportion is used for carrying out acid pickling treatment on the initial copper foil, so that the oxide on the surface of the initial copper foil can be removed, the treatment effect of subsequent roughening treatment is improved, the roughened copper foil obtained after roughening treatment is more beneficial to processing, the firmness of a plating layer on the surface of the copper foil is improved, and copper powder is not easy to generate in the use process of the copper foil.

It is understood that a water washing treatment may be performed between the pickling treatment and the roughening treatment to avoid the influence of the pickling solution on the roughening treatment.

In some embodiments of the invention, a corrosion protection treatment is also included after the third curing treatment;

in the anti-corrosion treatment: the current density is 3-8A/dm²The temperature is 30-60 ℃;

corrosion-inhibiting solution for corrosion-inhibiting treatment: the concentration of zinc ions is 2-20 g/L, the concentration of potassium pyrophosphate is 70-350 g/L, and the pH value of the anti-corrosion solution is 9.0-10.0.

In the invention, after the third curing treatment, the obtained copper foil is subjected to corrosion prevention treatment by using a corrosion prevention solution, so that the corrosion prevention performance of the copper foil is improved. Further, the corrosion prevention treatment with the above process conditions can make the copper foil have better corrosion prevention performance.

It can be understood that a water washing treatment can be performed between the third curing treatment and the corrosion prevention treatment, and the water washing treatment can wash away the third curing liquid remaining on the surface of the copper foil to improve the treatment effect of the corrosion prevention treatment.

In some embodiments of the invention, an oxidation prevention treatment is further included after the corrosion prevention treatment;

in the anti-oxidation treatment: the current density is 5-8A/dm²The temperature is 30-40 ℃;

among the oxidation preventing agents used for the oxidation preventing treatment: the concentration of hexavalent chromium ions is 2 to 7g/L, and the pH of the antioxidant is 10.0 to 12.0.

In the invention, after the anti-corrosion treatment, the copper foil with anti-corrosion performance is subjected to anti-oxidation treatment by using an antioxidant, so that the anti-oxidation performance of the copper foil is improved. Furthermore, the anti-oxidation treatment with the process conditions can enable the copper foil to have better anti-oxidation performance.

It can be understood that a water washing treatment can be included between the corrosion protection layer treatment and the oxidation protection treatment, and the water washing treatment can wash away the corrosion protection solution on the surface of the copper foil to improve the treatment effect of the oxidation protection treatment.

In some embodiments of the present invention, the method of processing a copper foil further comprises: after the anti-oxidation treatment, silane coupling treatment is carried out on the copper foil with the anti-oxidation performance by using a silane coupling agent, and a layer of organic film is formed on the surface of the copper foil, so that the anti-oxidation capability and the welding resistance of the copper foil are further improved, the binding force between the copper foil and a base material is improved, and the prepared multilayer fine circuit board has better quality.

In some embodiments, the silane coupling treatment temperature is 20 to 30 ℃ and the silane coupling agent concentration is 0.5 to 2.0 g/L.

It can be understood that water washing treatment can be included between the anti-oxidation treatment and the silane coupling treatment, and the water washing treatment can wash away the anti-oxidation agent on the surface of the copper foil and improve the treatment effect of the silane coupling treatment.

Further, the copper foil after silane coupling treatment is placed in an atmosphere of 180-200 ℃ for drying treatment, and the residual solvent on the surface of the copper foil is dried, so that the copper foil with better comprehensive performance is obtained.

Fig. 1 is an apparatus for processing copper foil according to some embodiments of the present invention. As shown in fig. 1, the device for processing copper foil includes an unwinding unit, an acid washing unit, a first washing unit, a roughening unit, a first curing unit, a second curing unit, a third curing unit, a second washing unit, an anti-corrosion unit, a third washing unit, an anti-oxidation unit, a fourth washing unit, a silane coupling unit, a drying unit and a winding unit, which are connected in sequence; the apparatus for processing copper foil further comprises a transfer unit;

the initial copper foil is unreeled through the unreeling unit under the transmission of the transmission unit and sequentially passes through the acid cleaning unit, the first water washing unit, the coarsening unit, the first curing unit, the second curing unit, the third curing unit, the second water washing unit, the anti-corrosion unit, the third water washing unit, the anti-oxidation unit, the fourth water washing unit, the silane coupling unit, the drying unit and the reeling unit.

In the present invention, the pickling unit, the first washing unit, the roughening unit, the first curing unit, the second curing unit, the third curing unit, the second washing unit, the corrosion preventing unit, the third washing unit, the oxidation preventing unit, the fourth washing unit, and the silane coupling unit are referred to as functional units. In the present invention, the structure of the functional unit is exemplified by taking the pickling unit as an example, and the pickling unit of the present invention may include a pickling tank for accommodating a pickling solution.

The conveying unit comprises N sub-conveying units, wherein N is greater than or equal to 1, and the sub-conveying units can be conveying belts and/or conveying rollers. In the invention, a sub-transmission unit is arranged in each functional unit, a sub-transmission unit is arranged between any two adjacent functional units, a sub-transmission unit is arranged between the unreeling unit and the adjacent functional unit, a sub-transmission unit is arranged between the drying unit and the winding unit, and the sub-transmission units are sequentially connected to drive the initial copper foil to move. The present invention is not limited to the conveying speed of the conveying unit, and the conveying speed may be 15 to 35m/min in some embodiments.

Specifically, the initial copper foil is unreeled through an unreeling unit under the transmission of a transmission unit, enters an acid cleaning unit under the transmission of the transmission unit, and is subjected to acid cleaning treatment through acid cleaning solution to remove oxides on the surface of the initial copper foil; the initial copper foil after acid washing treatment enters a first washing unit for water washing treatment under the transmission of a transmission unit, and residual acid washing solution on the surface is washed away; then, the copper foil enters a roughening unit under the transmission of the transmission unit, and is roughened by roughening liquid to obtain roughened copper foil; the roughened copper foil enters a first curing unit under the transmission of the transmission unit, and is subjected to first curing treatment by first curing liquid to obtain a first cured copper foil; the first solidified copper foil enters a second solidified unit under the transmission of the transmission unit, and is solidified by a second solidified liquid to obtain a second solidified copper foil; the second solidified copper foil enters a third solidification unit under the transmission of the transmission unit and is subjected to third solidification treatment by a third solidification liquid; the third solidified liquid enters a second water washing unit for water washing treatment under the transmission of the transmission unit, and the third solidified liquid is washed away; then the copper foil enters an anti-corrosion unit under the transmission of the transmission unit and is subjected to anti-corrosion treatment by an anti-corrosion solution to obtain a copper foil with anti-corrosion performance; the copper foil with the corrosion resistance enters a third water washing unit for water washing treatment under the transmission of the transmission unit, and the corrosion-resistant solution on the surface of the copper foil is washed away; then the copper foil enters an anti-oxidation unit under the transmission of the transmission unit and is subjected to anti-oxidation treatment by an antioxidant to obtain a copper foil with anti-oxidation performance; the copper foil with the anti-oxidation performance enters a fourth washing unit for washing treatment under the transmission of the transmission unit, and the anti-oxidation agent on the surface of the copper foil is washed away; then the copper foil enters a silane coupling unit under the transmission of the transmission unit, and silane coupling treatment is carried out through a silane coupling agent, so that the oxidation resistance of the copper foil is further improved; the copper foil after silane coupling treatment enters a drying unit for drying treatment under the transmission of a transmission unit, and the residual solvent on the surface of the copper foil is dried; and finally, the copper foil is conveyed into a winding unit through a conveying unit, and the obtained copper foil is wound.

In a second aspect, the present invention provides a copper foil processed by the above processing method.

The copper foil provided by the invention has a firm surface coating, almost no copper powder is generated in the using process, and the copper foil can be used for preparing a high-quality multi-layer fine circuit board.

The technical solution of the present invention will be further described below with reference to specific examples.

Example 1

The processing method of the copper foil of the embodiment comprises the following steps:

1) acid pickling treatment

Placing the initial copper foil on a conveying unit, feeding the initial copper foil into an acid washing unit under the conveying of the conveying unit, and carrying out acid washing treatment on the initial copper foil by using an acid washing solution;

wherein the thickness of the initial copper foil is 35 μm, and the conveying speed of the conveying unit is 22 m/min; the temperature is 35 ℃;

the acid washing solution is a copper sulfate solution, and in the acid washing solution: the concentration of sulfuric acid was 150g/L and the concentration of copper ions was 25 g/L.

2) Roughening treatment

Conveying the acid-washed initial copper foil into a roughening unit under the conveying of the conveying unit, and electroplating the acid-washed initial copper foil by using roughening liquid to obtain a roughened copper foil;

wherein the current density is 30A/dm²The temperature is 30 ℃;

the coarsening solution is a copper sulfate solution, and the coarsening solution comprises the following components in percentage by weight: the concentration of sulfuric acid is 115g/L, the concentration of copper ions is 12.5g/L, and the concentration of chloride ions is 15 mg/L.

3) First curing treatment

The roughened copper foil enters a first curing unit under the transmission of the transmission unit, and the roughened copper foil is electroplated by using first curing liquid to obtain a first cured copper foil;

wherein the current density is 30A/dm²The temperature is 45 ℃; the first solidifying liquid is a copper sulfate solution, and the first solidifying liquid comprises the following components in percentage by weight: the concentration of copper ions was 40g/L and the concentration of sulfuric acid was 100 g/L.

4) Second curing treatment

The first solidified copper foil enters a second solidified unit under the transmission of the transmission unit, and the first solidified copper foil is electroplated by using a second solidified liquid to obtain a second solidified copper foil;

wherein the current density is 70A/dm²The temperature is 45 ℃; the second solidifying liquid is a copper sulfate solution, and the second solidifying liquid comprises the following components: the concentration of copper ions was 75 g/L and the concentration of sulfuric acid was 100 g/L.

5) Third curing treatment

The second solidified copper foil enters a third solidified unit under the transmission of the transmission unit, and the second solidified copper foil is electroplated by using a third solidified liquid;

wherein the current density is 70A/dm²The temperature is 45 ℃; the third solidifying liquid is a copper sulfate solution, and in the third solidifying liquid: the concentration of copper ions was 75 g/L and the concentration of sulfuric acid was 100 g/L.

6) Anti-corrosion treatment

The copper foil after the third curing treatment enters an anti-corrosion treatment unit under the transmission of the transmission unit, and anti-corrosion treatment is carried out by using an anti-corrosion solution to obtain an anti-corrosion copper foil;

wherein the current density is 5.5A/dm²The temperature is 35 ℃; the anti-corrosion solution is zinc sulfate solution, and in the anti-corrosion solution: the concentration of zinc ions was 6g/L, the concentration of potassium pyrophosphate was 150g/L, and the pH of the corrosion protection solution was 9.5.

7) Oxidation-preventing treatment

The anticorrosive copper foil enters the anti-oxidation treatment unit under the transmission of the transmission unit, and the anti-oxidation treatment is carried out on the anticorrosive copper foil by using an anti-oxidation agent to obtain an anti-oxidation copper foil;

wherein the current density is 6.5A/dm²The temperature is 35 ℃; the antioxidant is chromic anhydride solution, and comprises the following components: the concentration of hexavalent chromium ions was 3.5g/L, and the pH of the antioxidant was 11.

8) Silane coupling treatment

The anti-oxidation copper foil enters the silane coupling unit under the transmission of the transmission unit, and silane coupling treatment is carried out on the anti-oxidation copper foil by using a silane coupling agent;

wherein the temperature is 25 ℃, and the concentration of the silane coupling agent is 1.25 g/L.

9) Drying treatment

The copper foil after silane coupling treatment enters a drying unit for drying treatment under the transmission of a transmission unit to obtain a copper foil;

wherein the temperature is 190 ℃.

Example 2

The processing method of the copper foil of the embodiment comprises the following steps:

1) acid pickling treatment

Placing the initial copper foil on a conveying unit, feeding the initial copper foil into an acid washing unit under the conveying of the conveying unit, and carrying out acid washing treatment on the initial copper foil by using an acid washing solution;

wherein the thickness of the initial copper foil is 35 μm, and the conveying speed of the conveying unit is 22 m/min; the temperature is 35 ℃;

the acid washing solution is a copper sulfate solution, and in the acid washing solution: the concentration of sulfuric acid was 150g/L and the concentration of copper ions was 25 g/L.

2) Roughening treatment

Conveying the acid-washed initial copper foil into a roughening unit under the conveying of the conveying unit, and electroplating the acid-washed initial copper foil by using roughening liquid to obtain a roughened copper foil;

wherein the current density is 30A/dm²The temperature is 30 ℃;

the coarsening solution is a copper sulfate solution, and the coarsening solution comprises the following components in percentage by weight: the concentration of sulfuric acid is 115g/L, the concentration of copper ions is 12.5g/L, and the concentration of chloride ions is 15 mg/L.

3) First curing treatment

The roughened copper foil enters a first curing unit under the transmission of the transmission unit, and the roughened copper foil is electroplated by using first curing liquid to obtain a first cured copper foil;

wherein the current density is 30A/dm²At a temperature of 50 ℃; first curing liquidIs a copper sulfate solution, and in the first curing solution: the concentration of copper ions was 35g/L and the concentration of sulfuric acid was 70 g/L.

4) Second curing treatment

The first solidified copper foil enters a second solidified unit under the transmission of the transmission unit, and the first solidified copper foil is electroplated by using a second solidified liquid to obtain a second solidified copper foil;

wherein the current density is 70A/dm²At a temperature of 50 ℃; the second solidifying liquid is a copper sulfate solution, and the second solidifying liquid comprises the following components: the concentration of copper ions was 65 g/L and the concentration of sulfuric acid was 70 g/L.

5) Third curing treatment

The second solidified copper foil enters a third solidified unit under the transmission of the transmission unit, and the second solidified copper foil is electroplated by using a third solidified liquid;

wherein the current density is 70A/dm²At a temperature of 50 ℃; the third solidifying liquid is a copper sulfate solution, and in the third solidifying liquid: the concentration of copper ions was 65 g/L and the concentration of sulfuric acid was 70 g/L.

6) Anti-corrosion treatment

The copper foil after the third curing treatment enters an anti-corrosion treatment unit under the transmission of the transmission unit, and anti-corrosion treatment is carried out by using an anti-corrosion solution to obtain an anti-corrosion copper foil;

wherein the current density is 5.5A/dm²The temperature is 35 ℃; the anti-corrosion solution is zinc sulfate solution, and in the anti-corrosion solution: the concentration of zinc ions was 6g/L, the concentration of potassium pyrophosphate was 150g/L, and the pH of the corrosion protection solution was 9.5.

7) Oxidation-preventing treatment

The anticorrosive copper foil enters the anti-oxidation treatment unit under the transmission of the transmission unit, and the anti-oxidation treatment is carried out on the anticorrosive copper foil by using an anti-oxidation agent to obtain an anti-oxidation copper foil;

wherein the current density is 6.5A/dm²The temperature is 35 ℃; the antioxidant is chromic anhydride solution, and comprises the following components: the concentration of hexavalent chromium ions was 3.5g/L, and the pH of the antioxidant was 11.

8) Silane coupling treatment

The anti-oxidation copper foil enters the silane coupling unit under the transmission of the transmission unit, and silane coupling treatment is carried out on the anti-oxidation copper foil by using a silane coupling agent;

wherein the temperature is 25 ℃, and the concentration of the silane coupling agent is 1.25 g/L.

9) Drying treatment

The copper foil after silane coupling treatment enters a drying unit for drying treatment under the transmission of a transmission unit to obtain a copper foil;

wherein the temperature is 190 ℃.

Comparative example 1

The processing method of the copper foil of the comparative example includes the steps of:

1) acid pickling treatment

Placing the initial copper foil on a conveying unit, feeding the initial copper foil into an acid washing unit under the conveying of the conveying unit, and carrying out acid washing treatment on the initial copper foil by using an acid washing solution;

wherein the thickness of the initial copper foil is 35 μm, and the conveying speed of the conveying unit is 22 m/min; the temperature is 35 ℃;

the acid washing solution is a copper sulfate solution, and in the acid washing solution: the concentration of sulfuric acid was 150g/L and the concentration of copper ions was 25 g/L.

2) First roughening treatment

Conveying the acid-washed initial copper foil into a first roughening unit under the conveying of a conveying unit, and electroplating the acid-washed initial copper foil by using a first roughening solution to obtain a first roughened copper foil;

wherein the current density is 30A/dm²The temperature is 30 ℃;

the first coarsening solution is a copper sulfate solution, and in the first coarsening solution: the concentration of sulfuric acid is 115g/L, the concentration of copper ions is 12.5g/L, and the concentration of chloride ions is 15 mg/L.

3) Second roughening treatment

The first roughened copper foil enters a second roughening unit under the transmission of the transmission unit, and second roughening treatment is carried out on the first roughened copper foil by using second roughening liquid to obtain a second roughened copper foil;

wherein the current density is 30A/dm²The temperature is 30 ℃;

the second coarsening solution is a copper sulfate solution, and in the second coarsening solution: the concentration of sulfuric acid is 115g/L, the concentration of copper ions is 12.5g/L, and the concentration of chloride ions is 15 mg/L.

4) First curing treatment

The second roughened copper foil enters the first curing unit under the transmission of the transmission unit, and the second roughened copper foil is electroplated by using the first curing liquid to obtain a first cured copper foil;

wherein the current density is 30A/dm²The temperature is 45 ℃; the first solidifying liquid is a copper sulfate solution, and the first solidifying liquid comprises the following components in percentage by weight: the concentration of copper ions was 40g/L and the concentration of sulfuric acid was 100 g/L.

5) Second curing treatment

The first solidified copper foil enters a second solidified unit under the transmission of the transmission unit, and the first solidified copper foil is electroplated by using a second solidified liquid to obtain a second solidified copper foil;

wherein the current density is 30A/dm²The temperature is 45 ℃; the second solidifying liquid is a copper sulfate solution, and the second solidifying liquid comprises the following components: the concentration of copper ions was 40g/L and the concentration of sulfuric acid was 100 g/L.

6) Anti-corrosion treatment

The second solidified copper foil enters an anti-corrosion treatment unit under the transmission of the transmission unit, and anti-corrosion treatment is carried out on the second solidified copper foil by using an anti-corrosion solution to obtain an anti-corrosion copper foil;

wherein the current density is 5.5A/dm²The temperature is 35 ℃; the anti-corrosion solution is zinc sulfate solution, and in the anti-corrosion solution: the concentration of zinc ions was 6g/L, the concentration of potassium pyrophosphate was 150g/L, and the pH of the corrosion protection solution was 9.5.

7) Oxidation-preventing treatment

The anticorrosive copper foil enters the anti-oxidation treatment unit under the transmission of the transmission unit, and the anti-oxidation treatment is carried out on the anticorrosive copper foil by using an anti-oxidation agent to obtain an anti-oxidation copper foil;

wherein the current density is 6.5A/dm²The temperature is 35 ℃; the antioxidant is chromic anhydride solution, and comprises the following components: the concentration of hexavalent chromium ions was 3.5g/L, and the pH of the antioxidant was 11.

8) Silane coupling treatment

The anti-oxidation copper foil enters the silane coupling unit under the transmission of the transmission unit, and silane coupling treatment is carried out on the anti-oxidation copper foil by using a silane coupling agent;

wherein the temperature is 25 ℃, and the concentration of the silane coupling agent is 1.25 g/L.

9) Drying treatment

The copper foil after silane coupling treatment enters a drying unit for drying treatment under the transmission of a transmission unit to obtain a copper foil;

wherein the temperature is 190 ℃.

Comparative example 2

The processing method of the copper foil of the comparative example includes the steps of:

1) acid pickling treatment

Placing the initial copper foil on a conveying unit, feeding the initial copper foil into an acid washing unit under the conveying of the conveying unit, and carrying out acid washing treatment on the initial copper foil by using an acid washing solution;

wherein the thickness of the initial copper foil is 35 μm, and the conveying speed of the conveying unit is 22 m/min; the temperature is 35 ℃;

the acid washing solution is a copper sulfate solution, and in the acid washing solution: the concentration of sulfuric acid was 150g/L and the concentration of copper ions was 25 g/L.

2) First roughening treatment

Conveying the acid-washed initial copper foil into a first roughening unit under the conveying of a conveying unit, and electroplating the acid-washed initial copper foil by using a first roughening solution to obtain a first roughened copper foil;

wherein the current density is 30A/dm²The temperature is 30 ℃;

the first coarsening solution is a copper sulfate solution, and in the first coarsening solution: the concentration of sulfuric acid is 115g/L, the concentration of copper ions is 12.5g/L, and the concentration of chloride ions is 15 mg/L.

3) First curing treatment

The second roughened copper foil enters the first curing unit under the transmission of the transmission unit, and the second roughened copper foil is electroplated by using the first curing liquid to obtain a first cured copper foil;

wherein the current density is 30A/dm²Temperature ofThe temperature is 45 ℃; the first solidifying liquid is a copper sulfate solution, and the first solidifying liquid comprises the following components in percentage by weight: the concentration of copper ions was 40g/L and the concentration of sulfuric acid was 100 g/L.

4) Second roughening treatment

The first roughened copper foil enters a second roughening unit under the transmission of the transmission unit, and second roughening treatment is carried out on the first roughened copper foil by using second roughening liquid to obtain a second roughened copper foil;

wherein the current density is 30A/dm²The temperature is 30 ℃;

the second coarsening solution is a copper sulfate solution, and in the second coarsening solution: the concentration of sulfuric acid is 115g/L, the concentration of copper ions is 12.5g/L, and the concentration of chloride ions is 15 mg/L.

5) Second curing treatment

The first solidified copper foil enters a second solidified unit under the transmission of the transmission unit, and the first solidified copper foil is electroplated by using a second solidified liquid to obtain a second solidified copper foil;

wherein the current density is 30A/dm²The temperature is 45 ℃; the second solidifying liquid is a copper sulfate solution, and the second solidifying liquid comprises the following components: the concentration of copper ions was 40g/L and the concentration of sulfuric acid was 100 g/L.

6) Third curing treatment

The first solidified copper foil enters a second solidified unit under the transmission of the transmission unit, and the first solidified copper foil is electroplated by using a second solidified liquid to obtain a second solidified copper foil;

wherein the current density is 30A/dm²The temperature is 45 ℃; the second solidifying liquid is a copper sulfate solution, and the second solidifying liquid comprises the following components: the concentration of copper ions was 40g/L and the concentration of sulfuric acid was 100 g/L.

7) Fourth curing treatment

The first solidified copper foil enters a second solidified unit under the transmission of the transmission unit, and the first solidified copper foil is electroplated by using a second solidified liquid to obtain a second solidified copper foil;

wherein the current density is 30A/dm²The temperature is 45 ℃; the second solidifying liquid is a copper sulfate solution, and the second solidifying liquid comprises the following components: the concentration of copper ions was 40g/L and the concentration of sulfuric acid was 100 g/L.

8) Anti-corrosion treatment

The second solidified copper foil enters an anti-corrosion treatment unit under the transmission of the transmission unit, and anti-corrosion treatment is carried out on the second solidified copper foil by using an anti-corrosion solution to obtain an anti-corrosion copper foil;

wherein the current density is 5.5A/dm²The temperature is 35 ℃; the anti-corrosion solution is zinc sulfate solution, and in the anti-corrosion solution: the concentration of zinc ions was 6g/L, the concentration of potassium pyrophosphate was 150g/L, and the pH of the corrosion protection solution was 9.5.

9) Oxidation-preventing treatment

The anticorrosive copper foil enters the anti-oxidation treatment unit under the transmission of the transmission unit, and the anti-oxidation treatment is carried out on the anticorrosive copper foil by using an anti-oxidation agent to obtain an anti-oxidation copper foil;

wherein the current density is 6.5A/dm²The temperature is 35 ℃; the antioxidant is chromic anhydride solution, and comprises the following components: the concentration of hexavalent chromium ions was 3.5g/L, and the pH of the antioxidant was 11.

10) Silane coupling treatment

The anti-oxidation copper foil enters the silane coupling unit under the transmission of the transmission unit, and silane coupling treatment is carried out on the anti-oxidation copper foil by using a silane coupling agent;

wherein the temperature is 25 ℃, and the concentration of the silane coupling agent is 1.25 g/L.

11) Drying treatment

The copper foil after silane coupling treatment enters a drying unit for drying treatment under the transmission of a transmission unit to obtain a copper foil;

wherein the temperature is 190 ℃.

Comparative example 3

The processing method of the copper foil of the comparative example includes the steps of:

1) acid pickling treatment

Placing the initial copper foil on a conveying unit, feeding the initial copper foil into an acid washing unit under the conveying of the conveying unit, and carrying out acid washing treatment on the initial copper foil by using an acid washing solution;

wherein the thickness of the initial copper foil is 35 μm, and the conveying speed of the conveying unit is 22 m/min; the temperature is 35 ℃;

the acid washing solution is a copper sulfate solution, and in the acid washing solution: the concentration of sulfuric acid was 150g/L and the concentration of copper ions was 25 g/L.

2) First roughening treatment

Conveying the acid-washed initial copper foil into a first roughening unit under the conveying of a conveying unit, and electroplating the acid-washed initial copper foil by using a first roughening solution to obtain a first roughened copper foil;

wherein the current density is 30A/dm²The temperature is 30 ℃;

the first coarsening solution is a copper sulfate solution, and in the first coarsening solution: the concentration of sulfuric acid is 115g/L, the concentration of copper ions is 12.5g/L, and the concentration of chloride ions is 15 mg/L.

3) First curing treatment

The second roughened copper foil enters the first curing unit under the transmission of the transmission unit, and the second roughened copper foil is electroplated by using the first curing liquid to obtain a first cured copper foil;

wherein the current density is 30A/dm²The temperature is 45 ℃; the first solidifying liquid is a copper sulfate solution, and the first solidifying liquid comprises the following components in percentage by weight: the concentration of copper ions was 40g/L and the concentration of sulfuric acid was 100 g/L.

4) Second roughening treatment

The first roughened copper foil enters a second roughening unit under the transmission of the transmission unit, and second roughening treatment is carried out on the first roughened copper foil by using second roughening liquid to obtain a second roughened copper foil;

wherein the current density is 30A/dm²The temperature is 30 ℃;

the second coarsening solution is a copper sulfate solution, and in the second coarsening solution: the concentration of sulfuric acid is 115g/L, the concentration of copper ions is 12.5g/L, and the concentration of chloride ions is 15 mg/L.

5) Second curing treatment

The first solidified copper foil enters a second solidified unit under the transmission of the transmission unit, and the first solidified copper foil is electroplated by using a second solidified liquid to obtain a second solidified copper foil;

wherein the current density is 30A/dm²The temperature is 45 ℃; the second solidifying liquid is a copper sulfate solution, and the second solidifying liquid comprises the following components: concentration of copper ionsThe degree is 40g/L and the concentration of sulfuric acid is 100 g/L.

6) Third curing treatment

The first solidified copper foil enters a second solidified unit under the transmission of the transmission unit, and the first solidified copper foil is electroplated by using a second solidified liquid to obtain a second solidified copper foil;

wherein the current density is 30A/dm²The temperature is 45 ℃; the second solidifying liquid is a copper sulfate solution, and the second solidifying liquid comprises the following components: the concentration of copper ions was 40g/L and the concentration of sulfuric acid was 100 g/L.

7) Anti-corrosion treatment

The second solidified copper foil enters an anti-corrosion treatment unit under the transmission of the transmission unit, and anti-corrosion treatment is carried out on the second solidified copper foil by using an anti-corrosion solution to obtain an anti-corrosion copper foil;

wherein the current density is 5.5A/dm²The temperature is 35 ℃; the anti-corrosion solution is zinc sulfate solution, and in the anti-corrosion solution: the concentration of zinc ions was 6g/L, the concentration of potassium pyrophosphate was 150g/L, and the pH of the corrosion protection solution was 9.5.

8) Oxidation-preventing treatment

The anticorrosive copper foil enters the anti-oxidation treatment unit under the transmission of the transmission unit, and the anti-oxidation treatment is carried out on the anticorrosive copper foil by using an anti-oxidation agent to obtain an anti-oxidation copper foil;

wherein the current density is 6.5A/dm²The temperature is 35 ℃; the antioxidant is chromic anhydride solution, and comprises the following components: the concentration of hexavalent chromium ions was 3.5g/L, and the pH of the antioxidant was 11.

9) Silane coupling treatment

The anti-oxidation copper foil enters the silane coupling unit under the transmission of the transmission unit, and silane coupling treatment is carried out on the anti-oxidation copper foil by using a silane coupling agent;

wherein the temperature is 25 ℃, and the concentration of the silane coupling agent is 1.25 g/L.

10) Drying treatment

The copper foil after silane coupling treatment enters a drying unit for drying treatment under the transmission of a transmission unit to obtain a copper foil;

wherein the temperature is 190 ℃.

The copper foils obtained in the examples and comparative examples were characterized,

1) scanning Electron Microscope (SEM)

The surfaces of the copper foils produced in examples and comparative examples were observed using SEM. FIG. 2 is a surface SEM photograph of a copper foil produced in example 1 of the present invention; FIG. 3 is an SEM photograph of a copper foil produced in example 2 of the present invention; FIG. 4 is a surface SEM photograph of a copper foil produced in comparative example 1 of the present invention; FIG. 5 is a surface SEM photograph of a copper foil produced in comparative example 2 of the present invention; fig. 6 is a surface SEM image of the copper foil manufactured in comparative example 3 of the present invention. As can be seen from fig. 2 to 6, the surface of the copper foil prepared in the example of the present invention has a trefoil structure, and fine particles on the surface of the copper foil are finer.

2) Copper powder testing

And (3) placing filter paper with the size of 30 square centimeters on the surface of the copper foil, placing a 500g weight on the surface of the filter paper to enable the filter paper to move on the surface of the copper foil, and observing the falling-off condition of the copper powder on the surface of the copper foil by using a metallographic microscope after the filter paper moves back and forth on the surface of the copper foil.

It was observed that the copper foil prepared in example 1 had 5 copper powders smaller than 30 μm on the surface and no copper powders larger than 30 μm; the surface of the copper foil prepared in example 2 has 10 copper powders smaller than 30 μm and 3 copper powders larger than 30 μm; the surface of the copper foil prepared in comparative example 1 had 23 copper powders smaller than 30 μm and 8 copper powders larger than 30 μm; the surface of the copper foil prepared in comparative example 2 had 12 copper powders smaller than 30 μm and 6 copper powders larger than 30 μm; the surface of the copper foil prepared in comparative example 3 had 18 copper powders smaller than 30 μm and 5 copper powders larger than 30 μm. It is shown that the surface of the copper foil prepared in example 1 of the present invention is stronger.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.