Rolled copper foil and surface electroplating method and application thereof

Abstract

The invention relates to the technical field of rolled copper foils, in particular to a rolled copper foil surface electroplating method, a rolled copper foil and application of the rolled copper foil. The rolled copper foil surface electroplating method comprises the following steps that pretreatment is conducted, specifically, rolled rolled copper foil is sequentially subjected to degreasing, acid pickling, roughening and curing treatment; wherein in the pickling step, current is introduced into a pickling solution, and a rolled copper foil is used as a cathode; and electroplating treatment: carrying out electroplating treatment on the pretreated rolled copper foil so as to form a target plating layer on the surface of the rolled copper foil. According to the invention, the problem of uneven distribution of coating particles caused by the existing copper foil electroplating method is solved, and the performance of the rolled copper foil is improved, so that the difficulty and the cost of a subsequent precision manufacturing process are reduced, and the overall production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of rolled copper foil, and in particular to a rolled copper foil surface electroplating method, the rolled copper foil and applications of the rolled copper foil. Background Art

[0002] In today's era of rapid technological development, cutting-edge fields such as 5G communications, the Internet of Things, automotive electronics, industrial robots, and industrial intelligence are developing at an unprecedented speed, and copper foil, as one of the core electronic materials, has been put forward increasingly stringent performance standards. In particular, in high-end application fields such as precision circuit boards (PCBs), high-frequency and high-speed signal transmission, flexible electronics, and micro-nano manufacturing, rolled copper foil plays an indispensable role with its excellent ductility, folding resistance, high density, and low surface roughness.

[0003] However, the uneven distribution of plating particles in the existing electroplating process constitutes a major technical problem in the production of rolled copper foil. This unevenness not only weakens the copper foil's peel strength, etching performance and welding ability, but may also introduce additional dielectric losses, which will have an adverse effect on the transmission efficiency and signal integrity of high-frequency signals. In addition, the uneven particle structure may also increase the difficulty and cost of subsequent precision manufacturing processes such as laser drilling, thereby negatively affecting the efficiency and economy of the overall production process.

[0004] In view of this, it is urgent to develop a new electroplating process that can evenly distribute the plating particles on the surface of the copper foil. Summary of the invention

[0005] In view of the above problems, the present invention is proposed to provide a surface electroplating method of a rolled copper foil, a rolled copper foil and an application that overcome the above problems or at least partially solve the above problems, and can solve the problem of uneven distribution of coating particles caused by the existing copper foil electroplating method, so as to improve the performance of the rolled copper foil, thereby reducing the difficulty and cost of subsequent precision manufacturing processes and improving overall production efficiency.

[0006] Specifically, the present invention provides a method for electroplating the surface of a rolled copper foil, comprising the following steps:

[0007] Pretreatment: degreasing, pickling, roughening and curing the rolled copper foil in sequence; wherein, in the pickling step, current is passed through the pickling solution, and the rolled copper foil is used as a cathode to form a layer of copper particles on the surface of the rolled copper foil;

[0008] Electroplating treatment: electroplating the pre-treated rolled copper foil to form a target plating layer on the surface of the rolled copper foil.

[0009] Optionally, in the pickling step:

[0010] The concentration of H2SO4 in the pickling solution is 80-150 g / L;

[0011] The temperature of the pickling solution is 20-50°C;

[0012] The current density used is 1000~1500A / m 2 .

[0013] Optionally, in the electroplating step, the electroplating solution includes boric acid or borax.

[0014] Optionally, the electroplating treatment is a copper-nickel alloy plating treatment to form a black treated surface on the surface of the rolled copper foil.

[0015] Optionally, in the copper-nickel alloy plating step:

[0016] The concentration of CuSO4 in the electroplating solution is 15-20 g / L, the concentration of NiSO4 is 160-200 g / L, the concentration of sodium citrate is 70-100 g / L, the concentration of sodium acetate is 5-10 g / L, the concentration of boric acid or borax is 0-5 g / L, and the concentration of glycine is 5-50 g / L;

[0017] The pH value of the plating solution is 4 to 5;

[0018] The temperature of the plating solution is 35-55°C;

[0019] The current density used is 1000A / m 2 ;

[0020] The electrode distance is 60mm;

[0021] The plating time is 12 seconds.

[0022] Optionally, the degreasing step comprises in sequence:

[0023] Chemical degreasing: The concentration of NaOH in the chemical degreasing solution is 30-50 g / L, and the concentration of Na2CO3 is 20-40 g / L;

[0024] Electrolytic degreasing: The working temperature of the electrolytic degreasing liquid is 30-60°C; the electrode distance is 60mm, and the current density used is 1500A / m 2 .

[0025] Optionally, in the roughening step:

[0026] Cu in the roughening solution 2+ The concentration of is 10-20 g / L, and the concentration of H2SO4 is 200-230 g / L;

[0027] The temperature of the roughening liquid is 20℃~50℃;

[0028] The electrode distance is 60 mm and the current density is 1500 A / m 2 ;

[0029] The roughening time was 10 seconds.

[0030] Optionally, in the curing step:

[0031] Cu in solidifying liquid 2+ The concentration of is 45~80g / L, and the concentration of H2SO4 is 120~160g / L;

[0032] The temperature of the solidifying liquid is 30-50°C;

[0033] The electrode distance is 60mm;

[0034] The current density used is 3000A / m 2 ;

[0035] The curing time is 10 seconds.

[0036] On the other hand, the present invention also provides a rolled copper foil obtained by any of the above-mentioned methods for electroplating the surface of the rolled copper foil.

[0037] On the other hand, the present invention also provides an application of the rolled copper foil in the field of circuit boards.

[0038] In the rolled copper foil surface electroplating method, rolled copper foil and application of the present invention, a current is added in the pickling step before roughening, so that a layer of small-particle copper can be plated on the surface of the rolled copper foil, thereby effectively improving the surface flatness of the rolled copper foil after pickling, creating favorable conditions for the uniform distribution of the subsequent target coating, and making the target coating smoother.

[0039] Furthermore, the coating particles of the rolled copper foil are evenly distributed, thereby ensuring that the rolled copper foil can exert more stable and excellent performance in the subsequent use process. Specifically, the present invention can significantly improve the quality and comprehensive performance of the rolled copper foil, so that the rolled copper foil can meet the use requirements of high-end electronic manufacturing industries such as high-speed signal transmission and precision circuit design, and can also reduce the difficulty and cost of subsequent precision manufacturing processes, and improve the overall production efficiency of related products.

[0040] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0042] Figure 1 is a scanning electron microscope image of the surface of the rolled copper foil of Example 1;

[0043] Figure 2 This is a scanning electron microscope image of the surface of the rolled copper foil of Comparative Example 1. DETAILED DESCRIPTION

[0044] A first aspect of the present invention provides a method for electroplating the surface of a rolled copper foil, which may include the following steps:

[0045] Pretreatment: Degreasing, pickling, roughening and curing are performed on the rolled copper foil in sequence;

[0046] Electroplating treatment: The pre-treated rolled copper foil is electroplated to form a target coating on the surface of the rolled copper foil.

[0047] In the pickling step, current is passed through the pickling solution, and the rolled copper foil is used as a cathode to form a layer of copper particles on the surface of the rolled copper foil. Specifically, during the pickling process, the pickling solution reacts with the rolled copper foil to remove the oxide layer and rust on the surface of the rolled copper foil, and copper ions are formed in the pickling solution; in addition, current is passed through the pickling tank, and the rolled copper foil is used as a cathode. Under the action of the current, the copper ions in the pickling tank are plated onto the surface of the rolled copper foil, and a copper plating layer is formed.

[0048] Since the current is passed in the pickling step before roughening in this embodiment, a layer of small-particle copper can be plated on the surface of the rolled copper foil while the rolled copper foil is pickled, thereby effectively improving the surface flatness of the rolled copper foil after pickling, creating favorable conditions for the subsequent formation of the target coating, and making the target coating particles evenly distributed and the target coating smoother.

[0049] Furthermore, since the surface coating particles of the rolled copper foil prepared by the present invention are evenly distributed, it is ensured that the rolled copper foil can exert more stable and excellent performance in the subsequent use process. Specifically, the present invention can significantly improve the quality and comprehensive performance of the rolled copper foil, so that the rolled copper foil can meet the use requirements of high-end electronic manufacturing industries such as high-speed signal transmission and precision circuit design, and can also reduce the difficulty and cost of subsequent precision manufacturing processes, and improve the overall production efficiency of related products.

[0050] In some optional embodiments of the present invention, in the pickling step, the concentration of H2SO4 in the pickling solution is 80-150 g / L. For example, the concentration of H2SO4 in the pickling solution can be any one of 80 g / L, 90 g / L, 100 g / L, 110 g / L, 120 g / L, 130 g / L, 140 g / L, and 150 g / L.

[0051] In some optional embodiments of the present invention, in the pickling step, the temperature of the pickling solution is 20-50° C. For example, the temperature of the pickling solution can be any one of 20° C., 25° C., 30° C., 35° C., 40° C., 45° C., and 50° C.

[0052] In some optional embodiments of the present invention, in the pickling step, the current density used is 1000-1500A / m 2 For example, the current density used can be 1000A / m 2 、1100A / m 2 , 1200A / m, 1300A / m 2 、1400A / m 2 、1500A / m 2 Any value in .

[0053] In some optional embodiments of the present invention, in the electroplating step, the electroplating solution includes boric acid or borax. Since the boron element is more easily enriched at the grain boundaries of copper grains during electroplating, it will affect the diffusion of solute atoms at the solidification interface, the growth curvature of the interface, and the occurrence of re-nucleation, thereby limiting the growth of copper grains and achieving the purpose of grain refinement. Therefore, in this embodiment, the introduction of boron element into the electroplating solution can significantly refine the target coating particles, thereby facilitating the improvement of the uniformity and flatness of the coating particles.

[0054] In some optional embodiments of the present invention, the electroplating process is a copper-nickel alloy plating process to form a black treatment surface on the surface of the rolled copper foil. In some alternative embodiments, the electroplating process can also be other types of electroplating processes.

[0055] In some optional embodiments of the present invention, in the copper-nickel alloy plating step: the concentration of CuSO4 in the plating solution is 15-20 g / L (for example, 15 g / L, 16 g / L, 17 g / L, 18 g / L, 19 g / L or 20 g / L), the concentration of NiSO4 is 160-200 g / L (for example, 160 g / L, 170 g / L, 180 g / L, 190 g / L or 200 g / L), and the concentration of sodium citrate is 70-100 g / L (for example, 70 g / L, 80 g / L). / L, 90g / L, 95g / L or 100g / L), sodium acetate 5-10g / L (for example, 5g / L, 6g / L, 7g / L, 8g / L, 9g / L or 10g / L), the concentration of boric acid or borax is 0-5g / L (for example, 0g / L, 1g / L, 2g / L, 3g / L, 4g / L or 5g / L), and the concentration of glycine is 5-50g / L (for example, 5g / L, 10g / L, 20g / L, 30g / L, 40g / L or 50g / L).

[0056] In some optional embodiments of the present invention, in the copper-nickel alloy plating step: the pH value of the plating solution is 4 to 5. For example, the pH value of the plating solution can be any one of 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, and 5.

[0057] In some optional embodiments of the present invention, in the copper-nickel alloy plating step: the temperature of the plating solution is 35-55° C. For example, the temperature of the plating solution can be any one of 35° C., 38° C., 40° C., 45° C., 50° C., 52° C., 53° C., 54° C., and 55° C.

[0058] In some optional embodiments of the present invention, in the copper-nickel alloy plating step: the current density used is 1000A / m 2 .

[0059] In some optional embodiments of the present invention, in the copper-nickel alloy plating step: the electrode distance is 60 mm.

[0060] In some optional embodiments of the present invention, in the copper-nickel alloy plating step: the electroplating time is 12 seconds.

[0061] In some optional embodiments of the present invention, the degreasing step includes: chemical degreasing and electrolytic degreasing in sequence.

[0062] In the chemical degreasing step, the concentration of NaOH in the chemical degreasing liquid is 30-50 g / L (e.g., 30 g / L, 40 g / L, 45 g / L or 50 g / L), and the concentration of Na2CO3 is 20-40 g / L (e.g., 20 g / L, 25 g / L, 30 g / L, 40 g / L or 50 g / L).

[0063] In the electrolytic degreasing step, the working temperature of the electrolytic degreasing solution is 30 to 60°C (for example, 30°C, 40°C, 45°C, 50°C, 55°C or 60°C); the electrode distance is 60mm, and the current density used is 1500A / m 2 .

[0064] In some optional embodiments of the present invention, the degreasing step includes chemical degreasing or electrolytic degreasing.

[0065] In some optional embodiments of the present invention, in the roughening step: Cu in the roughening solution 2+ The concentration of H2SO4 is 10-20 g / L (for example: 10 g / L, 11 g / L, 15 g / L, 18 g / L or 20 g / L), and the concentration of H2SO4 is 200-230 g / L (for example: 200 g / L, 205 g / L, 210 g / L, 220 g / L, 225 g / L or 230 g / L).

[0066] In some optional embodiments of the present invention, in the roughening step: the temperature of the roughening liquid is 20°C to 50°C (for example: 20°C, 25°C, 30°C, 35°C, 40°C or 50°C).

[0067] In some optional embodiments of the present invention, in the roughening step: the electrode distance is 60 mm, the current density used is 1500 A / m 2 .

[0068] In some optional embodiments of the present invention, in the roughening step: the roughening time is 10 seconds.

[0069] In some optional embodiments of the present invention, in the curing step: Cu in the curing liquid 2+ The concentration of H2SO4 is 45g / L~80g / L (for example: 45g / L, 50g / L, 60g / L, 70g / L, 75g / L or 80g / L), and the concentration of H2SO4 is 120~160g / L (for example: 120g / L, 125g / L, 130g / L, 140g / L, 150g / L or 160g / L).

[0070] In some optional embodiments of the present invention, in the curing step: the temperature of the curing liquid is 30-50°C (for example: 30°C, 35°C, 40°C, 45°C, 48°C or 50°C).

[0071] In some optional embodiments of the present invention, in the curing step: the electrode distance is 60 mm.

[0072] In some optional embodiments of the present invention, in the curing step: the current density used is 3000A / m 2 .

[0073] In some optional embodiments of the present invention, in the curing step: the curing time is 10 seconds.

[0074] In some optional embodiments of the present invention, the thickness of the rolled copper foil substrate used in the present invention is within 70 μm, and the tensile strength of the copper foil substrate without heat treatment is between 380 and 480 MPa. In other words, the thickness of the rolled copper foil after rolling is within 70 μm, and the tensile strength of the rolled copper foil without heat treatment is between 380 and 480 MPa.

[0075] A second aspect of the present invention provides a rolled copper foil, which is a rolled copper foil prepared by the rolled copper foil surface electroplating method described in any one of the embodiments of the first aspect.

[0076] The third aspect of the present invention provides an application of the rolled copper foil as described in the second aspect in the field of circuit boards.

[0077] The embodiments of the present application will be described in detail below in conjunction with examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are preferably referred to the guidance provided in the present application, and can also be based on the experimental manual or normal conditions in this area, can also be based on the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0078] Example 1

[0079] A method for electroplating the surface of a rolled copper foil may include the following steps:

[0080] 1. Pretreatment: The rolled copper foil is subjected to chemical degreasing, electrolytic degreasing, pickling, roughening and curing treatments in sequence. The thickness of the rolled copper foil is 35 μm. That is, the thickness of the copper foil substrate used in the present invention is 35 μm.

[0081] Specifically, in the chemical degreasing step: the concentration of NaOH in the chemical degreasing solution is 30-50 g / L, and the concentration of Na2CO3 is 20-40 g / L.

[0082] In the electrolytic degreasing step: the composition of the electrolytic degreasing liquid is the same as that of the chemical degreasing liquid, the working temperature of the electrolytic degreasing liquid is 30-60°C; the electrode distance is 60mm, and the current density used is 1500A / m 2 .

[0083] In the pickling step: current is passed through the pickling solution, and the rolled copper foil is used as a cathode to form a layer of copper particles on the surface of the rolled copper foil; wherein the concentration of H2SO4 in the pickling solution is 80-150 g / L; the temperature of the pickling solution is 20-50°C; the current density used is 1000-1500 A / m 2 .

[0084] In the roughening step: Cu in the roughening solution 2+ The concentration of is 10-20 g / L, the concentration of H2SO4 is 200-230 g / L; the temperature of the coarsening solution is 20℃-50℃; the electrode distance is 60 mm, and the current density is 1500 A / m 2 ; The roughening time is 10 seconds.

[0085] In the curing step: Cu in the curing liquid 2+ The concentration of is 45-80g / L, the concentration of H2SO4 is 120-160g / L; the temperature of the solidifying liquid is 30-50℃; the electrode distance is 60mm; the current density used is 3000A / m 2 ; Curing time is 10 seconds.

[0086] 2. Electroplating treatment: The pre-treated rolled copper foil is subjected to copper-nickel alloy plating treatment to form a copper-nickel alloy plating layer on the surface of the rolled copper foil, and a finished rolled copper foil with a black treated surface is obtained.

[0087] In the copper-nickel alloy plating treatment step: the concentration of CuSO4 in the plating solution is 15-20 g / L, the concentration of NiSO4 is 160-200 g / L, the concentration of sodium citrate is 70-100 g / L, the concentration of sodium acetate is 5-10 g / L, the concentration of boric acid or borax is 0-5 g / L, and the concentration of glycine is 5-50 g / L; the pH value of the plating solution is 4-5; the temperature of the plating solution is 35-55° C.; the current density used is 1000 A / m 2 ; The electrode distance is 60 mm; The electroplating time is 12 seconds.

[0088] The finished rolled copper foil prepared in this embodiment was subjected to organizational analysis and performance testing:

[0089] Observation under a scanning electron microscope, such as Figure 1 As shown, the surface coating particles of the rolled copper foil finished product are evenly distributed, with small particle size and good coating flatness.

[0090] Tested by a universal testing machine, the tensile strength of the finished rolled copper foil reaches 450MPa, and the elongation after break is ≥1.1%. Its physical and chemical properties meet the requirements of rolled copper foil for fine and dense circuits.

[0091] The rolled copper foil was cut into sheet samples and placed in a high-temperature forced air drying oven at 200°C for 2 hours. The samples were bright in color and did not undergo oxidation discoloration, indicating that the coating had good antioxidant properties.

[0092] It can be seen that the finished rolled copper foil prepared in this embodiment has the beneficial effects of good coating flatness and good comprehensive performance. This is mainly due to the following three factors: on the one hand, before the rough curing step, the surface of the rolled copper foil is flattened by pickling to increase the current, which effectively improves the flatness of the copper foil surface after the acidification treatment, creates extremely favorable conditions for the subsequent formation of the copper-nickel alloy coating, and is conducive to improving the flatness of the copper-nickel alloy coating and the uniformity of the coating particles. On the other hand, the introduction of boron elements into the copper-nickel alloy plating solution can significantly refine the coating particles. On the other hand, during the electroplating process, the process parameters are optimized to achieve an ultra-low profile, prevent oxidation discoloration, and improve its corrosion resistance.

[0093] In summary, this embodiment has developed an innovative electroplating process, which aims to achieve uniform distribution of plating particles on the surface of copper foil, and has become the key to improving the performance of rolled copper foil and meeting the needs of high-end electronic manufacturing. This process can not only significantly improve the comprehensive performance of copper foil, meet the stringent requirements of cutting-edge technologies such as high-speed signal transmission and precision circuit design, but also achieve production cost savings and minimize environmental impact by optimizing material utilization and reducing energy consumption. At the same time, this technological breakthrough has far-reaching strategic significance for promoting the independent innovation and development of the domestic electronic materials industry.

[0094] Comparative Example 1

[0095] The difference between Comparative Example 1 and Example 1 is that no boron element is added in the copper-nickel alloy plating step, that is, the copper-nickel alloy plating process conditions are: the concentration of CuSO4 is 15-20 g / L, the concentration of NiSO4 is 160-200 g / L, the concentration of sodium citrate is 70-100 g / L, the concentration of sodium acetate is 5-10 g / L, the concentration of glycine is 5-50 g / L, the pH is 4-5, the temperature of the plating solution is 35°C-55°C, and the current density used is 1000 A / m 2 , the electroplating time is 12 seconds, and the electrode distance is 60 mm; other operations and steps are the same as those in Example 1.

[0096] like Figure 1 and Figure 2 As shown, by comparing the electron microscope images of the black treatment surface of the rolled copper foil of Example 1 and Comparative Example 1, it can be seen that: Example 1 ( Figure 1 ) compared with the coating particles in Comparative Example 1 ( Figure 2 ) is more uniform, and there is basically no lack of plating area, and the coating has better flatness and density. This shows that boron can effectively refine the copper-nickel alloy coating particles, improve its density and flatness, and thus enhance its corrosion resistance.

[0097] Multiple exemplary embodiments of the present invention, however, without departing from the spirit and scope of the present invention, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the content disclosed in the present invention. Therefore, the scope of the present invention should be understood and identified as covering all these other variations or modifications.

Claims

1. A method for electroplating the surface of a rolled copper foil, characterized in that: The following steps are involved: Pretreatment: degreasing, pickling, roughening and curing the rolled copper foil in sequence; wherein, in the pickling step, current is passed through the pickling solution, and the rolled copper foil is used as a cathode to form a layer of copper particles on the surface of the rolled copper foil; Electroplating treatment: electroplating the pre-treated rolled copper foil to form a target plating layer on the surface of the rolled copper foil.

2. The method for electroplating the surface of rolled copper foil according to claim 1, characterized in that: In the pickling step: The concentration of H2SO4 in the pickling solution is 80-150 g / L; The temperature of the pickling solution is 20-50°C; The current density used is 1000~1500A / m 2 .

3. The method for electroplating the surface of rolled copper foil according to claim 1, characterized in that: In the electroplating treatment step, the electroplating solution includes boric acid or borax.

4. The method for electroplating the surface of rolled copper foil according to claim 3, characterized in that: The electroplating treatment is a copper-nickel alloy plating treatment to form a black treated surface on the surface of the rolled copper foil.

5. The method for electroplating the surface of rolled copper foil according to claim 4, characterized in that: In the copper-nickel alloy plating process step: The concentration of CuSO4 in the electroplating solution is 15-20 g / L, the concentration of NiSO4 is 160-200 g / L, the concentration of sodium citrate is 70-100 g / L, the concentration of sodium acetate is 5-10 g / L, the concentration of boric acid or borax is 0-5 g / L, and the concentration of glycine is 5-50 g / L; The pH value of the plating solution is 4 to 5; The temperature of the plating solution is 35-55°C; The current density used is 1000A / m 2 ; The electrode distance is 60mm; The plating time is 12 seconds.

6. The method for electroplating the surface of rolled copper foil according to claim 1, characterized in that: The degreasing step comprises in sequence: Chemical degreasing: The concentration of NaOH in the chemical degreasing solution is 30-50 g / L, and the concentration of Na2CO3 is 20-40 g / L; Electrolytic degreasing: The working temperature of the electrolytic degreasing liquid is 30-60°C; the electrode distance is 60mm, and the current density used is 1500A / m 2 .

7. The method for electroplating the surface of rolled copper foil according to claim 1, characterized in that: In the roughening step: Cu in the roughening solution 2+ The concentration of is 10-20 g / L, and the concentration of H2SO4 is 200-230 g / L; The temperature of the roughening liquid is 20℃~50℃; The electrode distance is 60 mm and the current density is 1500 A / m 2 ; The roughening time was 10 seconds.

8. The method for electroplating the surface of rolled copper foil according to claim 1, characterized in that: In the curing step: Cu in solidifying liquid 2+ The concentration of is 45~80g / L, and the concentration of H2SO4 is 120~160g / L; The temperature of the solidifying liquid is 30-50°C; The electrode distance is 60mm; The current density used is 3000A / m 2 ; The curing time is 10 seconds.

9. A rolled copper foil obtained by the surface electroplating method of rolled copper foil according to any one of claims 1 to 8.

10. Use of the rolled copper foil according to claim 9 in the field of circuit boards.

Images