CN119332322A

CN119332322A - Preparation method of copper foil

Info

Publication number: CN119332322A
Application number: CN202411887928.6A
Authority: CN
Inventors: 闫瑞刚; 缪永华; 周建华; 王志红; 陈红磊; 李帅; 王卫; 张群梅
Original assignee: Jiangdong Electronic Material Co ltd; Harbin Institute of Technology Shenzhen; Jiangsu Zhongtian Technology Co Ltd
Current assignee: Jiangdong Electronic Material Co ltd; Harbin Institute of Technology Shenzhen; Jiangsu Zhongtian Technology Co Ltd
Priority date: 2024-12-20
Filing date: 2024-12-20
Publication date: 2025-01-21

Abstract

The preparation method of the copper foil comprises the steps of providing a carrier layer, forming a metal oxide layer on the carrier layer, forming a copper foil on the surface, facing away from the carrier layer, of the carrier layer, connecting the copper foil with the carrier layer through the metal oxide layer, and separating the copper foil from the metal oxide layer through reduction treatment. The preparation method of the copper foil can reduce the preparation cost of the copper foil, and the preparation process can not cause harm to people and environment.

Description

Method for preparing copper foil

Technical Field

The application relates to the technical field of copper foil preparation, in particular to a preparation method of copper foil.

Background

With the development of higher integration and miniaturization of electronic products, copper foil plays an increasingly important role in electronic manufacturing.

The copper foil can be prepared by adopting a carrier attaching mode. An electrolytic copper foil is used as a carrier foil, a peeling layer is formed thereon, then a target copper foil is deposited, and then the carrier foil is effectively separated from the target copper foil. The release layer material includes metallic materials, alloys, and organics to achieve efficient separation of the carrier foil from the target copper foil.

However, the release layer is costly in material or may be harmful to the human body and the environment. For example, the release layer material may include a metal material containing rare earth elements, which is costly. The release layer material may comprise organic materials, which typically comprise organic compounds such as benzotriazole, benzimidazole, thiocyanic acid and derivatives thereof, most of which are toxic and may pose a hazard to the human body and environment.

Disclosure of Invention

The embodiment of the application provides the preparation method of the copper foil, which can reduce the preparation cost of the copper foil, and the preparation process does not adopt materials which are harmful to people and environment.

The invention provides a preparation method of a copper foil, which comprises the following steps:

providing a carrier layer;

Forming a metal oxide layer on the carrier layer;

forming a copper foil on the surface of the oxidized metal layer, which is away from the carrier layer, wherein the copper foil is connected with the carrier layer through the oxidized metal layer;

and reducing the metal oxide layer, wherein the copper foil is separated from the metal oxide layer.

Optionally, the metal oxide layer is provided as a copper oxide layer.

Optionally, forming a metal oxide layer on the carrier layer, including:

providing an oxidizing electrolyte;

And electrifying the carrier layer by taking the carrier layer as a cathode, wherein the carrier layer forms the oxidized metal layer through the oxidized electrolyte.

Optionally, the solvent of the oxidizing electrolyte is water;

the solutes of the oxidizing electrolyte include sulfuric acid, copper sulfate pentahydrate, sodium hydroxide, and an oxidizing agent.

Optionally, the oxidizing agent comprises hydrogen peroxide;

the solute of the oxidizing electrolyte comprises 50-150 g/L sulfuric acid, 15-25 g/L copper sulfate pentahydrate, 50-100 g/L sodium hydroxide and 5-15 g/L hydrogen peroxide.

Optionally, forming a copper foil on a surface of the oxidized metal layer facing away from the carrier layer, including:

Providing an electrolyte;

and electrifying at least one of the carrier layer and the metal oxide layer by taking the carrier layer and the metal oxide layer as cathodes, wherein the metal oxide layer forms the copper foil through the electrolyte.

Optionally, the solvent of the electrolyte is water;

the solutes of the electrolyte include sulfuric acid and copper sulfate pentahydrate.

Optionally, the reducing the metal oxide layer includes:

The oxidized metal layer is arranged in a reduction cavity;

And introducing a reducing gas into the reducing cavity so as to enable the reducing gas to reduce the oxidized metal layer.

Optionally, after disposing the oxidized metal layer in the reduction chamber, the method further includes:

and introducing inert gas into the reduction cavity to discharge oxygen in the reduction cavity.

Optionally, the carrier layer is provided as a thick copper layer, a copper-based alloy layer, a nickel layer, an aluminum layer, and an iron layer.

According to the preparation method of the copper foil, the metal oxide layer is subjected to reduction treatment, the metal oxide layer is set to be the copper oxide layer, the copper oxide layer has the characteristic of shrinkage in the reduction process, the metal oxide layer is separated from the carrier layer, and meanwhile, the metal oxide layer is separated from the copper foil to obtain the copper foil. The preparation cost of the copper foil prepared by the method is low, and the preparation process does not adopt materials harmful to the environment, so that the method has the advantages of environmental protection and greenness. The method has simple process flow and high operability.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of a method of making a copper foil;

FIG. 2 is an electron microscopic view of a first copper foil prepared;

FIG. 3 is an electron microscopic view of a second copper foil prepared;

FIG. 4 is an electron microscopic view of a third copper foil prepared;

Fig. 5 is an electron microscopic view of a fourth copper foil prepared.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application. The following embodiments and features of the embodiments may be combined with each other without conflict.

The invention provides a preparation method of copper foil, firstly, a carrier layer is provided. A metal oxide layer is then formed on the support layer. And then, forming a copper foil on the surface of the carrier layer, which is away from the carrier layer, wherein the copper foil is connected with the carrier layer through the oxidized metal layer. Finally, the copper foil is separated from the oxidized metal layer by reduction treatment of the oxidized metal layer.

Referring to fig. 1, the copper foil is prepared as follows:

Step S110, providing a carrier layer.

First, a carrier layer is provided, which is provided as a thick copper layer, a copper-based alloy layer, a nickel layer, an aluminum layer, and an iron layer. The material of the carrier layer is selected according to different application scenes and requirements.

In some embodiments, the carrier layer is provided as a copper foil. The copper foil needs to have good conductivity to facilitate formation of the oxidized metal layer.

In some embodiments, the carrier layer is provided as a copper-based alloy foil. Copper-based alloy foils possess specific properties such as higher hardness or corrosion resistance. These properties can be improved by selecting copper-based alloy foils as carrier layers to meet specific requirements.

Further, the carrier layer is provided as brass, bronze, cupronickel or phosphor copper. The materials are selected by comprehensively considering the conductivity, adhesive force, corrosion resistance, wear resistance, cost effectiveness and other factors of different materials.

Step S120, forming a metal oxide layer on the carrier layer.

Then, a metal oxide layer is formed on the provided support layer by oxidizing the electrolytic solution. The metal oxide layer may be formed by supplying an oxidizing electrolyte, and applying electricity to the carrier layer as a cathode to cause a chemical reaction. That is, by injecting an oxidizing electrolyte containing metal ions into the electrolytic cell and disposing a support layer as a cathode therein. Subsequently, a current is passed through the cell and the metal ions get electrons at the surface of the cathode (i.e. the carrier layer) and a reduction reaction takes place. The metal ions combine with the oxidant in the electrolyte to form a denser metal oxide layer on the surface of the support layer.

In some embodiments, the metal oxide layer is provided as a nickel oxide layer. The nickel oxide layer is formed by oxidizing the electrolyte. The bonding force between the nickel oxide layer and the copper foil is moderate, so that the copper foil and the carrier layer can be peeled off in the subsequent process by a chemical or physical method.

In other embodiments, the metal oxide layer is provided as a copper oxide layer. By this arrangement, other metal ions in the electrolyte can be prevented from being deposited on the copper foil during the electrolytic process, thereby affecting the purity of the finally produced copper foil.

In some embodiments, the solvent of the oxidizing electrolyte is water and the solutes of the oxidizing electrolyte include sulfuric acid, copper sulfate pentahydrate, sodium hydroxide, and an oxidizing agent. That is, water is the solvent of the electrolyte and is responsible for dissolving the solute to form a solution that can conduct electricity. During the electrolysis process, the solutes of the oxidizing electrolyte participate in the electrolysis reaction. For example, sulfuric acid and sodium hydroxide can adjust the pH of the oxidizing electrolyte, thereby affecting the conditions and efficiency of the electrolysis reaction. Copper sulfate pentahydrate provides copper ions for the formation of copper or copper oxides. The oxidizing agent may participate in the oxidation reaction to form a copper oxide layer.

In some embodiments, the oxidizing agent may be hydrogen peroxide. The oxidant can be sodium hypochlorite. The oxidant can be potassium persulfate. Different oxidizing agents affect the rate, uniformity and adhesion of the oxidation reaction of the copper oxide layer.

In some embodiments, the oxidizing electrolyte comprises a solute comprising 50-150 g/L sulfuric acid, 15-25 g/L copper sulfate pentahydrate, 50-100 g/L sodium hydroxide, and 5-15 g/L hydrogen peroxide. The arrangement is such that metal oxide layers of different thickness, uniformity and other physical properties are obtained. For example, an oxidizing electrolyte was prepared by adding 50g of sulfuric acid, 15g of copper sulfate pentahydrate, 50g of sodium hydroxide and 5g of hydrogen peroxide using 1L of water as a solvent and stirring uniformly.

In some embodiments, the oxidizing electrolyte comprises a solute comprising 10-100 g/L sulfuric acid, 1-5 mg/L hydrochloric acid, 2-15 g/L copper sulfate pentahydrate, 20-70 g/L sodium hydroxide, and 1-5 g/L hydrogen peroxide. The arrangement is such that metal oxide layers of different thickness, uniformity and other physical properties are obtained.

In some embodiments, the oxidizing electrolyte is at a temperature of 15 ℃ to 30 ℃. For example, the temperature of the oxidizing electrolyte is in the range of 15 ℃, 20 ℃, 25 ℃, 30 ℃, or any two of these. The temperature of the oxidizing electrolyte may affect many aspects such as chemical reaction rate, electrolysis efficiency, quality of the oxidized metal layer, etc., and the temperature of the oxidizing electrolyte is set by combining various factors.

In other embodiments, the oxidizing electrolyte is at a temperature of 25 ℃ to 55 ℃. For example, the oxidizing electrolyte temperature is in the range of 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, or any two of these. The temperature of the oxidizing electrolyte may affect many aspects such as chemical reaction rate, electrolysis efficiency, quality of the oxidized metal layer, etc., and the temperature of the oxidizing electrolyte is set by combining various factors.

In some embodiments, the plating reaction employs a two-electrode system with a cathode voltage of 2-5V, a current density of 0.5-5A/dm ², and a plating time of 30-50 s. So as to form an oxidized metal layer meeting the actual requirements.

In other embodiments, a two-electrode system is used for the electroplating reaction, the cathode voltage is 2-5V, the current density is 0.5-5A/dm ², and the electroplating time is 30 s-60 min. Similarly, a metal oxide layer meeting the actual requirements is formed.

In some embodiments, the metal oxide layer formed after electroplating requires cleaning and drying. The cleaning process can remove the pollutants such as electroplating solution, impurities and the like remained on the surface of the oxidized metal layer after electroplating, and avoid adverse effects on the subsequent process or product performance. The cleaned oxidized metal layer needs to be dried, and the surface of the dried oxidized metal layer is cleaner, so that the adhesive force of a subsequent plating layer is improved.

Further, the metal oxide layer formed after electroplating needs to be washed by absolute ethyl alcohol and deionized water in sequence and then dried. Thus, the cleaning effect can be improved, secondary pollution is avoided, and the drying process is promoted.

The absolute ethyl alcohol has good solubility and volatility, and can dissolve and take away impurities such as organic matters on the surface of the oxidized metal layer. The absolute ethyl alcohol can be volatilized rapidly in the cleaning process, so that the moisture on the surface can be taken away, the drying process is accelerated, the time can be saved, and the energy consumption can be reduced. After being cleaned by absolute ethyl alcohol, deionized water is used for cleaning, so that the cleanliness of the surface of the oxidized metal layer can be ensured. In addition, the deionized water avoids the risk of secondary pollution caused by the fact that various dissolved ions are removed and can be redeposited on the surface of the oxidized metal layer in the cleaning process.

And S130, forming a copper foil on the surface of the oxidized metal layer, which is away from the carrier layer, wherein the copper foil is connected with the carrier layer through the oxidized metal layer.

As described above, a metal oxide layer is formed on a carrier layer by electroplating, and then a copper foil to be produced needs to be electroplated on the metal oxide layer. Providing electrolyte for the copper foil forming process, and electrifying at least one of the carrier layer and the metal oxide layer by taking the carrier layer and the metal oxide layer as cathodes. That is, an electrolyte containing copper ions is first prepared, and the support layer and the metal oxide layer are used as a cathode. Subsequently, this cathode (support layer or oxidized metal layer thereon) is energized by an external power source, so that copper ions in the electrolyte acquire electrons at the cathode surface and undergo a reduction reaction. The copper ions are continuously reduced and deposited on the oxidized metal layer, and finally a layer of compact copper foil is formed. The copper foil is the copper foil to be prepared.

In some embodiments, the solvent of the electrolyte is water. The solutes of the electrolyte include sulfuric acid and copper sulfate pentahydrate. That is, water is the solvent of the electrolyte and is responsible for dissolving the solute to form a solution that can conduct electricity. During electrolysis, the solute of the electrolyte may participate in the electrolysis reaction.

Illustratively, sulfuric acid renders the electrolyte acidic and copper ions are more readily dissociated from the copper sulfate pentahydrate, facilitating the electrolytic process. Copper sulfate pentahydrate is the main source of copper ions in the electrolyte. In the electrolytic process, the copper sulfate pentahydrate dissociates copper ions, and the copper ions migrate to the cathode under the action of an electric field and are reduced to copper atoms on the surface of the cathode, so that the copper foil is gradually deposited.

In some embodiments, the electrolyte comprises a solute comprising 50-150 g/L sulfuric acid and 15-25 g/L copper sulfate pentahydrate. The copper foil is thus provided so as to have different thickness, uniformity and other characteristics in the oxidized metal layer by the electroplating reaction. For example, an electrolyte was prepared by adding 50g of sulfuric acid and 15g of copper sulfate pentahydrate using 1L of water as a solvent and stirring uniformly.

In other embodiments, the electrolyte comprises 5-20 g/L sulfuric acid and 3-15 g/L copper sulfate pentahydrate. The copper foil is thus arranged so as to have different physical properties such as thickness and uniformity in the oxidized metal layer by the plating reaction.

In some embodiments, the cathode voltage of the electroplating to form the copper foil on the surface of the oxidized metal layer is 0.1-10V, the current density is 20-40A/dm ², and the electroplating time is 1-20 s. So as to form the copper foil meeting the actual requirements.

In other embodiments, the cathode voltage of the electroplating for forming the copper foil on the surface of the oxidized metal layer is 0.1-10V, the current density is 20-40A/dm ², and the electroplating time is 30-3600 s. Similarly, this is done to form a copper foil that meets the actual requirements.

In some embodiments, the temperature of the electrolyte is 25 ℃ to 55 ℃. For example, the temperature of the electrolyte is in the range of 25 ℃,30 ℃, 35 ℃, 40 ℃, 45 ℃,50 ℃, 55 ℃, or any two of these. The temperature of the electrolyte may affect many aspects such as chemical reaction rate, electrolytic efficiency, quality of the copper foil, etc., and the temperature of the electrolyte is set by combining various factors.

Step S140, the metal oxide layer is subjected to reduction treatment, and the copper foil is separated from the metal oxide layer.

Prior to the reduction treatment, a metal oxide layer (with copper foil) formed by the support layer needs to be charged into a reduction chamber to effect the reduction reaction. Therefore, an inert gas is required to be introduced into the reduction chamber to discharge oxygen in the reduction chamber. By introducing inert gas into the reduction chamber, the oxygen concentration in the reduction chamber can be reduced, thereby preventing the oxidized metal layer from generating impurities or inconsistent with the expected reaction in the subsequent treatment process.

Further, the inert gas is set to argon. It is easy to understand that argon is colorless, odorless and nontoxic inert gas, has stable chemical property and is not easy to react with other substances. Therefore, argon is introduced into the reduction cavity, and oxygen in the reduction cavity is discharged, so that the subsequent treatment process of the oxidized metal layer can be prevented from reacting with the argon. And, the cost of argon is relatively low, and is easy to obtain and store. Thus, the use of argon as an inert gas can reduce the manufacturing cost.

In some embodiments, a metal oxide layer with copper foil attached (attached to a carrier layer) is disposed within the reduction chamber. The reducing gas is then introduced into the reducing chamber so that the reducing gas reduces the metal oxide layer. That is, a reducing gas, such as hydrogen or carbon monoxide, is introduced into the reduction chamber, and chemically reacts with the oxidized metal layer. In the reduction process of the metal oxide layer, the volume of the metal oxide layer is shrunk, the metal oxide layer is separated from the carrier layer, and meanwhile, the metal oxide layer is separated from the copper foil. The carrier layer is thus spontaneously separated from the copper foil, thereby obtaining a copper foil.

By the arrangement, the efficient and spontaneous separation between the carrier layer and the copper foil can be realized by utilizing the shrinkage characteristic of the volume when the oxidized metal layer is reduced. The preparation method of the embodiment of the application adopts the oxidized metal layer to replace the stripping layer in the traditional method to prepare the copper foil. This avoids the use of release layer materials which are costly or potentially harmful to the human body and the environment. The method simplifies the operation steps of the preparation, reduces the production cost of the preparation, avoids the use of harmful chemical substances in the preparation process, and meets the environmental protection requirement.

It is easy to understand that by controlling parameters such as flow rate, speed, pressure and the like of the reducing gas, the speed of shrinkage is adjustable, thereby realizing the adjustment of the reduction rate of the metal oxide layer. This affects the rate and extent of volume shrinkage of the oxidized metal layer, thereby enabling control of the stress distribution and separation process between the carrier layer and the copper foil. This helps to ensure the integrity and surface quality of the copper foil while reducing uncertainty and potential damage during separation.

In some embodiments, the reducing gas is provided as hydrogen. Hydrogen is a strong reducing agent capable of reducing a variety of metal oxides. The cost of hydrogen is relatively low and easy to obtain. In the reduction process, water is simultaneously generated, and the generated product is environment-friendly.

Illustratively, a metal oxide layer is disposed within the reduction chamber and seals the chamber. Then, hydrogen is introduced into the reduction chamber and adjusted to the set temperature and pressure conditions. Under the action of hydrogen, the oxidized metal layer starts to be reduced and gradually converted into metal. Meanwhile, parameters such as gas composition, temperature and the like in the reduction process need to be monitored regularly so as to ensure the stability and consistency of the reduction process.

In some embodiments, the reducing gas is provided as carbon monoxide. Carbon monoxide can be produced by a variety of routes including extraction from natural gas, coal, or biomass, among other sources. In addition, the carbon monoxide is relatively simple to store and transport, and the overall treatment cost is reduced. For example, in a reduction chamber, carbon monoxide chemically reacts with the oxidized metal layer to reduce the metal oxide to pure metal, while carbon dioxide is produced. Such reduction processes generally have a relatively high reaction rate and selectivity.

In some embodiments, the reducing gas is heat treated and the post-heating temperature is set to 300 ℃ to 400 ℃. The heat treatment of the reducing gas can improve the reduction reaction rate, optimize the reduction efficiency and enhance the process stability. For example, the temperature of the reducing gas is 300 ℃, 325 ℃, 350 ℃, 375 ℃, 400 ℃, or a range of any two of these. The temperature of the reducing gas may affect the reduction reaction rate, the reduction efficiency, the quality of the copper foil, etc., and the temperature of the reducing gas is set by combining various factors.

In other embodiments, the temperature of the reducing gas after heating is set to 400 ℃ to 500 ℃. The heat treatment of the reducing gas can improve the reduction reaction rate, optimize the reduction efficiency and enhance the process stability. For example, the temperature of the reducing gas is in the range of 400 ℃, 425 ℃, 450 ℃, 475 ℃, 500 ℃, or any two of these. The temperature of the reducing gas may affect the reduction reaction rate, the reduction efficiency, the quality of the copper foil, etc., and the temperature of the reducing gas is set by combining various factors.

In some embodiments, the time for reducing the metal oxide layer by the reducing gas is set to 5 to 30 minutes. The reduction time can shorten the period of the reduction treatment process, thereby improving the efficiency of copper foil preparation. Thus being beneficial to reducing the cost of preparing the copper foil and meeting the market demand for the copper foil. For example, the time of the reduction reaction is 5min, 10min, 15min, 20min, 25min, 30min, or a range of any two of these.

In other embodiments, the time for reducing the metal oxide layer with the reducing gas is set to 30-120 min. The reduction time can shorten the period of the reduction treatment process, thereby improving the efficiency of copper foil preparation. Thus being beneficial to reducing the cost of preparing the copper foil and meeting the market demand for the copper foil. For example, the time of the reduction reaction is 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, 120min, or a range consisting of any two thereof.

Finally, cooling the carrier with the copper foil and the oxidized metal layer to room temperature after the reduction reaction, and finally obtaining the ultrathin copper foil. During the reduction process, the volume of the oxidized metal layer shrinks and stresses are generated between the copper foil and the carrier layer. The cooling process helps to relieve these stresses, reducing warpage or deformation of the copper foil, and thereby improving the flatness of the copper foil. The copper foil at room temperature facilitates subsequent processing.

In some embodiments, the final cooling process is 30min to 180min. The cooling time can shorten the period of the cooling treatment process, thereby improving the efficiency of copper foil preparation. For example, the time of the reduction reaction is 30min, 60min, 90min, 120min, 150min, 180min, or a range of any two of these.

In some embodiments, the prepared copper foil is provided as an ultra-thin copper foil. The ultra-thin copper foil can be used for high-integration and miniaturized electronic products.

In some embodiments, the copper foil may be prepared to be 2-6 microns. For example, copper foil is prepared in the range of 2 microns, 3 microns, 4 microns, 5 microns, 6 microns, or any two of these.

In other embodiments, the copper foil may be prepared as an ultra-thin copper foil 250 nanometers thick.

Hereinafter, the method for preparing the copper foil of the present invention will be described in more detail by way of specific examples.

The raw materials used in each of the examples and comparative examples were obtained commercially by ordinary commercial route without any additional treatment unless specifically stated.

Example 1

The embodiment provides a preparation method of a copper foil, which comprises the following steps:

First, the carrier layer is provided as copper foil.

Then, water is used as a solvent, and solutes comprise 50g/L sulfuric acid, 5mg/L hydrochloric acid, 5g/L copper sulfate pentahydrate, 50g/L sodium hydroxide and 5g/L hydrogen peroxide to prepare an oxidation electrolyte. The temperature of the oxidizing electrolyte was set to 25 ℃. The copper foil is used as a cathode, the copper foil is electrified, a two-electrode system is adopted in the electroplating reaction, the cathode voltage is 2V, the current density is 5A/dm ², and the electroplating time is 40s. A copper oxide layer is formed on the copper foil by electroplating.

And then, cleaning and drying the surface of the copper oxide layer.

Next, water was used as a solvent, and solutes including 80g/L sulfuric acid and 20g/L copper sulfate pentahydrate were formulated to obtain an electrolyte. In this step, the cathode voltage of the plating was 5V, the current density was 20A/dm ², and the plating time was 10s. And electrifying the copper foil and the copper oxide layer by taking the copper foil and the copper oxide layer as cathodes, and forming the finally required copper foil on the copper oxide layer by electroplating.

And finally, introducing argon into the reduction cavity to discharge oxygen in the reduction cavity. Copper oxide layers (copper foil including both surfaces of the copper oxide layer) are disposed in the reduction chamber. Hydrogen was introduced into the reduction chamber and heated to 300 ℃. The time for reducing the copper oxide layer by hydrogen is set to be 5 minutes, so that the volume of the copper oxide layer can shrink in the reduction process, and the interface between the carrier layer and the prepared copper foil is spontaneously separated. And cooling to room temperature after the copper foil is taken out through the reduction reaction, and finally obtaining the copper foil.

Referring to fig. 2, it is shown that hydrogen is introduced into the reduction chamber, and the hydrogen reacts with the copper oxide layer in a reduction reaction. During this process, the copper oxide layer undergoes shrinkage in volume during the reduction process, causing spontaneous separation of the interface of the carrier layer with the prepared copper foil, thereby obtaining a copper foil having a thickness of about 2 μm.

Example 2 this example is substantially identical to example 1 except that the support layer is provided as a nickel layer and the other conditions remain unchanged.

Example 3 this example is substantially identical to example 1 except that the oxidizing electrolyte is formulated using water as the solvent and the solutes include 100g/L sulfuric acid, 20g/L copper sulfate pentahydrate, 75g/L sodium hydroxide and 10g/L hydrogen peroxide, with the other conditions remaining unchanged.

Example 4 this example is substantially identical to example 1 except that the electroplating time for forming the copper oxide layer is 30s to 10min, and other conditions are maintained.

With reference to the procedure of example 1, the copper foil was prepared in the above example, and the thickness of the prepared copper foil was measured. As shown in fig. 3,4 and 5, the thickness of the copper foil prepared in example 2 was about 400nm, the thickness of the copper foil prepared in example 3 was about 250nm, and the thickness of the copper foil prepared in example 4 was about 9 μm, as can be seen from the data of the thickness of the copper foil measured. The plating time of the carrier layer, the oxidizing electrolyte and the copper oxide layer all affect the thickness of the prepared copper foil.

It should be noted that references in the specification to "one embodiment," "an example embodiment," "some embodiments," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

Generally, terms should be understood at least in part by use in the context. For example, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in a singular sense, or may be used to describe a combination of features, structures, or characteristics in a plural sense, at least in part depending on the context. Similarly, terms such as "a" or "an" may also be understood to convey a singular usage or a plural usage, depending at least in part on the context.

It should be readily understood that "on," "above," and "above" in the present application should be interpreted in the broadest sense so that "on" means not only "directly on something," but also includes the meaning of "on something" with intermediate features or layers therebetween, and "on" or "above" includes the meaning of not only "on something" or "above," but also "above" and may include the meaning of "on something" or "above" with no intermediate features or layers therebetween (i.e., directly on something).

Further, spatially relative terms, such as "below," "beneath," "above," "over," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may have other orientations (90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the above embodiments are merely for illustrating the technical solution of the present application and not for limiting the same, and although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solution described in the above embodiments may be modified or some or all of the technical features may be equivalently replaced, and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A method for producing a copper foil, comprising:

providing a carrier layer;

Forming a metal oxide layer on the carrier layer;

2. The method of producing a copper foil according to claim 1, wherein the metal oxide layer is provided as a copper oxide layer.

3. The method of producing a copper foil according to claim 2, wherein forming a metal oxide layer on the carrier layer comprises:

providing an oxidizing electrolyte;

4. The method of producing a copper foil according to claim 3, wherein the solvent of the oxidizing electrolyte is water;

5. The method of producing a copper foil according to claim 4, wherein the oxidizing agent comprises hydrogen peroxide;

The solute of the oxidizing electrolyte comprises 50-150 g/L of sulfuric acid, 15-25 g/L of copper sulfate pentahydrate, 50-100 g/L of sodium hydroxide and 5-15 g/L of hydrogen peroxide.

6. The method of producing a copper foil according to claim 1, wherein forming a copper foil on a surface of the oxidized metal layer facing away from the carrier layer comprises:

Providing an electrolyte;

7. The method of producing a copper foil according to claim 6, wherein the solvent of the electrolytic solution is water;

8. The method of producing a copper foil according to any one of claims 1 to 7, wherein the reduction treatment of the oxidized metal layer comprises:

The oxidized metal layer is arranged in a reduction cavity;

9. The method of manufacturing a copper foil according to claim 8, wherein after disposing the oxidized metal layer in the reduction chamber, further comprising:

10. The method of producing a copper foil according to any one of claims 1 to 7, wherein the carrier layer is provided as a thick copper layer, a copper-based alloy layer, a nickel layer, an aluminum layer, and an iron layer.