Electrolytic copper foil applicable to the new generation of AI and communication industries and its manufacturing method

Abstract

The present invention discloses an electrolytic copper foil applicable to the new generation of AI and communication industries. The present invention also discloses a manufacturing method of the above copper foil, including: adding raw copper into sulfuric acid, stirring and dissolving, then filtering, and then mixing with an additive to obtain an electrolyte solution, and transferring the electrolyte solution to an electrolytic cell of a foil making machine; preparing a Cr anti-rust solution, filtering, and then transferring it to a chromium anti-oxidation tank of the foil making machine; applying an electric current to a separately arranged cathode roller and an anode plate, wherein the surface of the anode plate is provided with a honeycomb-shaped precise micro-pattern, electro-depositing copper on the surface of the cathode roller, and performing Cr anti-rust treatment through a roll-to-roll manufacturing process, and then winding and baking to obtain the electrolytic copper foil. The electrolytic copper foil of the present invention has the characteristics of low roughness, ultra-thin and high mechanical strength.

Description

Technical Field

[0001] The present invention belongs to the technical field of copper foils and their manufacturing methods, and relates to an electrolytic copper foil suitable for the new generation of AI and communication industries. The present invention also relates to a manufacturing method of the above copper foil. Background Art

[0002] Recently, the rapid development of artificial intelligence (AI) technology is leading a huge transformation in the entire industry. AI is widely applied in multiple fields such as manufacturing, finance, healthcare, and communication by processing large-scale data, recognizing patterns, autonomously learning, and making decisions. In particular, AI technology based on deep learning performs excellently in image recognition, speech recognition, natural language processing, etc. These AI systems require large-scale computing during the learning and reasoning processes, so high-performance hardware is essential. High-speed parallel computing devices such as GPUs (Graphics Processing Units) and TPUs (Tensor Processing Units) use dozens to hundreds of cores to achieve real-time data calculation, and high-speed signal transmission and power efficiency are also important factors. Therefore, the high-density circuit boards that make up these devices require conductive materials with excellent signal transmission characteristics, and copper foil plays a very crucial role as the core material. As a conductive material in the circuit, copper foil is used to transmit electrical signals. In a high-speed and high-frequency signal environment, its performance has a significant impact on the stability and efficiency of the entire system. Especially in AI computing devices and high-speed communication devices, the required copper foil must simultaneously meet extremely low surface roughness, precise thin-film characteristics, and excellent mechanical properties. If the surface roughness is large, due to the skin effect of high-frequency current flowing along the conductor surface, signal loss will increase; and if the thin-film characteristics are insufficient, it is difficult to achieve high-density circuits. In addition, the next-generation communication technology 6G (Sixth Generation) aims to use ultra-high frequency bands from 100 GHz to up to 1 THz to achieve data transmission speeds above 1 Tbps and ultra-low latency below 1 ms. However, at such high frequency bands, signal attenuation and propagation loss will increase sharply. Therefore, in order to minimize signal loss in the circuit, the surface state and thickness accuracy of the conductive material become more important. Therefore, in order to achieve stable transmission of ultra-high frequency signals, ultra-low roughness and thinning of copper foil are essential. However, the current commercialized electrolytic copper foil technology still has many technical limitations in fully meeting these high-performance requirements. First, the existing electrolytic copper foil has technical limitations in reducing the surface roughness to below a certain level in the manufacturing process, which leads to an increase in signal loss in high-frequency circuits. In addition, as the copper foil becomes thinner, its mechanical strength and thermal stability decrease, and physical defects such as peeling or cracking may occur during the circuit manufacturing process. Ultimately, the existing electrolytic copper foil is difficult to simultaneously meet the ultra-low roughness, thinning, and mechanical stability required by AI high-speed computing systems and 6G high-frequency communication circuits, and there are technical limitations. Therefore, the present invention aims to solve these problems and proposes a next-generation copper foil manufacturing technology that can reduce the surface roughness to an extremely low level while maintaining excellent mechanical properties. Summary of the Invention

[0003] An object of the present invention is to provide an electrolytic copper foil suitable for the new generation of AI and communication industries, having the characteristics of low roughness, ultra-thin, and high mechanical strength.

[0004] Another object of the present invention is to provide a method for manufacturing the above copper foil.

[0005] The technical solution adopted by the present invention is a method for manufacturing an electrolytic copper foil applicable to the new generation of AI and communication industries, which is specifically implemented according to the following steps:

[0006] Step 1: Add raw copper to sulfuric acid, stir and dissolve it, then filter, and then mix it with additives to obtain an electrolyte solution, and transfer the electrolyte solution to the electrolytic cell of the copper foil making machine;

[0007] Step 2: Prepare a Cr anti-rust solution, filter it, and then transfer it to the chromium anti-oxidation tank of the copper foil making machine;

[0008] Step 3: Apply an electric current to the separately arranged cathode roller and anode plate, electro-deposit copper on the surface of the cathode roller, and perform Cr anti-rust treatment through a roll-to-roll manufacturing process, and then wind it up and bake it to obtain an electrolytic copper foil;

[0009] Among them, the surface of the anode plate is provided with a honeycomb-shaped precision micro-pattern.

[0010] The characteristics of the present invention also lie in:

[0011] In Step 1, the electrolyte solution is obtained by mixing and dissolving pure copper wire and sulfuric acid, and then adding additives; among them, the concentration of copper ions is 85-100 g / L, and the concentration of sulfate ions is 90-120 g / L; the additives include a polishing agent, a retarder, a leveling agent, and a roughness regulator.

[0012] The polishing agent is one of sodium bis(3-sulfopropyl) disulfide, sodium 3-[(amino-iminomethyl)thio]-1-propanesulfonate, and sodium 3-(benzothiazol-2-ylthio)-propanesulfonate, and its addition amount is 15.0-50.0 mg / L;

[0013] The retarder is one of hydroxyethyl cellulose, octyl polyalkoxy ether, polyvinyl alcohol, polyethylpropylene glycol, and oleic acid polyethylene glycol ether, and its addition amount is 7.0-22.0 mg / L;

[0014] The leveling agent is 2-mercaptobenzimidazole, and its addition amount is 0.1-2.0 mg / L;

[0015] The roughness regulator is an arylene ether oligomer, and its addition amount is 2.0-10.0 mg / L.

[0016] In Step 2, the preparation method of the Cr anti-rust solution is:

[0017] Add chromium trioxide and glucose to ultrapure water, stir and dissolve to obtain; among them, the chromium ion concentration is 0.40-0.60 mg / L.

[0018] During the electroplating process in Step 3, the temperature of the electrolyte is 45 - 55°C, and the current density is 28 - 43 A / dm 2 , and the flow rate is 45 - 65 m 3 / hr.

[0019] During the Cr anti-rust treatment process in Step 3, the temperature of the anti-rust solution is 20 - 22°C, the flow rate is 3 - 6 m 3 / hr, and the pH value is below 3.5.

[0020] The baking process in Step 3 is specifically as follows: heat treatment is carried out at 50 - 65°C through an oven.

[0021] The honeycomb-shaped precision micro-patterns on the anode plate are formed by an array of regular hexagon patterns. The side length of the regular hexagon is 10 μm, the spacing between adjacent regular hexagons is 10 μm, and the pattern depth is 3 μm.

[0022] Another technical solution adopted by the present invention is an electrolytic copper foil applicable to the new generation of AI and communication industries, which is prepared by the above method. Its thickness is 3 - 5 μm, the surface roughness Ra is 0.05 - 0.1 μm, the tensile strength at normal temperature after heat treatment is 350 MPa - 400 MPa, and the elongation at normal temperature after heat treatment is 3.0 - 4.5%.

[0023] The beneficial effects of the present invention are as follows:

[0024] (1) The method of the present invention adopts an anode plate with a hexagonal (honeycomb-shaped) micro-pattern structure surface treatment different from the traditional technology in the manufacture of electrolytic copper foil, thereby maximizing the uniformity of current distribution and preventing current concentration phenomena, significantly reducing surface defects that may occur during coating deposition. This structural design significantly improves the surface roughness of the electrolytic copper foil and enables it to have optimized performance in high-frequency application fields requiring high-speed signal transmission;

[0025] (2) The method of the present invention adds additive C (leveling agent) and additive D (roughness regulator) in the electrolyte in the electrolytic cell in an optimal condition combination, inhibiting the formation of protrusions and peaks in the metal structure, while ensuring the roughness uniformity and mechanical stability of the coating. Additive C improves the mechanical properties, especially the tensile strength, of the electrolytic copper foil through a leveling effect, while additive D forms a smooth coating without micro-defects by more evenly controlling the current distribution. These two additives are the key elements to achieve high-performance electrolytic copper foil through a synergistic effect;

[0026] (3) The copper foil of the present invention has the following excellent physical properties: the thickness is 3 to 5 microns, the surface roughness Ra is 0.05 to 0.1 micron, the tensile strength at normal temperature after heat treatment is 350 MPa to 400 MPa, and the elongation at normal temperature after heat treatment is 3.0 to 4.5%. Under the condition of the same thickness, this electrolytic copper foil is no less inferior to the existing commercial copper foils. Moreover, by simultaneously achieving extremely low roughness and ultra-thin thickness, it becomes a material suitable for the new generation of high-speed signal processing. Therefore, the electrolytic copper foil of the present invention can be widely used as the core component material for industries such as the AI industry, 6G high-frequency communication industry, high-performance electronic devices, and ultra-precision circuit boards, and as a high-functional material for long-term stable operation in fields requiring high-speed transmission and high reliability. In addition, this technology is not limited to specific industries and is expected to be widely used as a key material for new generation high-performance products in various application fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a process flow chart of the manufacturing method of the electrolytic copper foil of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention will be described in detail below in conjunction with the drawings and specific embodiments.

[0029] The manufacturing method of the electrolytic copper foil suitable for the new generation of AI and communication industries of the present invention is as follows:

[0030] As Figure 1 shown, in order to manufacture the above-mentioned electrolytic copper foil, pure copper wire and sulfuric acid are injected into the dissolution tank, then dissolved and stirred. After that, the electrolyte is circulated and mixed through the waste liquid tank and the dissolution tank, and the concentration is controlled. In order to prevent crystallization caused by heat loss during the circulation of the electrolyte flowing in the pipeline, the temperature is controlled by a heat exchanger. Then, the impurities in the electrolyte are filtered through a diatomaceous earth filter and injected into the purified liquid tank. Next, the additives required for the stable manufacture of electrolytic copper foil and the additives required for high mechanical properties are placed in each additive tank, dissolved and stirred together with ultrapure water, and then also placed in the purified liquid tank. The electrolyte mixed with the additives in the purified liquid tank is filtered through a fine filter, and after the temperature of the electrolyte is adjusted by a heat exchanger, it is moved to the electrolytic cell of the foil making machine. Then, Cr salt and ultrapure water are dissolved and stirred in the Cr dissolution tank. After being dissolved well, it is transferred to the Cr supply tank to prepare an anti-rust solution to prevent the surface oxidation of the electrolytic copper foil. After being filtered through a fine filter, it is then moved to the chromium anti-oxidation tank in the foil making machine. In the electrolyte solution in the electrolytic cell, an electric current is applied to the cathode roller and the anode plate spaced apart from each other, and the electrolytic copper foil is electro-deposited on the surface of the cathode roller, and Cr anti-rust treatment is carried out through a roll-to-roll manufacturing process, and then it is wound up to complete the manufacture. Finally, in order to eliminate stress, the manufactured electrolytic copper foil needs to be heat-treated in an oven at 50 to 65 °C to complete the final processing.

[0031] In the above manufacturing method, the core of the present invention lies in the surface structure design of the anode plate for electrolytic copper foil manufacturing. A hexagonal (honeycomb-like) precise micro-pattern is constructed on the surface of the anode plate, and this structure plays a decisive role in the uniform dispersion of current flow during the electrolytic electroplating process. Specifically, the hexagonal honeycomb pattern overcomes the limitation of the planar structure where current concentration is likely to occur. By guiding the current to be evenly distributed on the anode surface, it significantly improves the thickness uniformity and surface roughness characteristics of the deposition layer. In an ordinary flat anode plate, excessive current concentration easily occurs in local areas, resulting in protrusions or depressions on the surface of the electrolytic copper foil, which may reduce the electrical properties. In contrast, the honeycomb pattern of the present invention fundamentally avoids these drawbacks and is an optimized structure that can achieve the ultra-low roughness characteristics required for high-frequency and ultra-precise circuits. The honeycomb pattern applied in the method of the present invention is composed of regular hexagonal units with a side length of 10 microns, the spacing between adjacent units is 10 microns, and the pattern depth (D) is 3 microns. At this time, the ratio of the depth to the unit size (D / W) is designed to be 0.3, which is an optimized ratio considering the current distribution and ion diffusion characteristics during the electrolysis process and is the core technology to achieve the effect of reducing roughness and simultaneously inducing stable deposition.

[0032] [Ratio of depth to unit size (D / W) = Pattern depth (D) / Unit size (W)]

[0033] In addition, the honeycomb anode plate of the present invention is not only limited to controlling roughness, but also stabilizes the flow of ions in the electrolyte through the regularity and repeatability of the pattern, thereby more precisely controlling the microcrystalline structure of the coating. This minimizes the occurrence probability of local thickness deviation or surface micro-defects of the electrolytic copper foil, especially in application fields requiring precise electrical characteristics, such as high-frequency signal processing circuits or circuit boards for AI high-performance chips, providing a key technical foundation for signal-loss-free and stable operation.

[0034] The electrolyte used to manufacture the above electrolytic copper foil is prepared by adding additives to a copper sulfate solution in which copper and sulfuric acid are dissolved and mixed. The concentration of copper ions is 85 - 100 g / L, the concentration of sulfate ions is 90 - 120 g / L, and high-purity copper wire with a purity greater than 99.9% is required for copper. The electrolyte temperature is 45 - 55 °C, the current density is 28 - 43 A / dm 2 ,and the flow rate is 45 - 65 m 3 / hr.

[0035] The additives added to the above electrolytic copper foil electrolyte are a polishing agent (additive A), a retarder (additive B), a leveling agent (additive C), and a roughness regulator (additive D). In particular, additives C and D are another important technical feature of the present invention.

[0036] The polishing agent (additive A) can be one of sodium bis(3-sulfopropyl) disulfide, sodium 3-[(aminoiminomethyl)thio]-1-propanesulfonate, and sodium 3-(benzothiazol-2-ylthio)propane-1-sulfonate, and the addition amount is 15.0 - 50.0 mg / L. When used in an appropriate amount, additive A can increase the electrodeposition rate and enhance the surface gloss. However, when the addition amount is less than 15.0 mg / L, the surface glossiness will decrease, and when the addition amount exceeds 50.0 mg / L, it may cause an increase in surface roughness or a decrease in tensile strength.

[0037] The retarder (additive B) can be one of hydroxyethyl cellulose, octyl polyalkoxy ether, polyvinyl alcohol, polyethylene propylene glycol, and polyethylene glycol oleate, and the addition amount is 7.0 - 22.0 mg / L. When used in an appropriate amount, additive B can reduce the electrodeposition rate, thereby preventing a sharp increase in surface roughness. However, if the addition amount is less than 7.0 mg / L, the surface roughness may increase sharply; in addition, after the addition amount exceeds 22.0 mg / L, the effect will not be enhanced compared with the appropriate amount, but will instead lead to an increase in manufacturing cost and economic waste.

[0038] The planarizing agent (additive C) can be 2-mercaptobenzimidazole, and the addition amount is 0.1 - 2.0 mg / L. When used in an appropriate amount, additive C can inhibit the formation of large protrusions or peaks in the metal structure, thereby planarizing the surface and improving the tensile strength and density by inducing a fine grain structure. At the same time, additive C can also relieve the local stress distribution inside the coating by adjusting the unevenness of the metal growth rate. However, if the addition amount is less than 0.1 mg / L, it is difficult to achieve the planarizing effect of the metal structure; if the addition amount exceeds 2.0 mg / L, it may cause an excessive increase in surface roughness or a decrease in tensile strength.

[0039] The roughness regulator (additive D) uses aryl ether oligomers, and the addition amount is 2.0 - 10.0 mg / L. When used in an appropriate amount, additive D can make the current distribution more uniform, thereby guiding the uniform deposition of the coating and showing excellent effects in reducing roughness and microdefects. However, if the addition amount is less than 2.0 mg / L, the current distribution will be uneven, which may lead to local overplating, resulting in an uneven electroplated layer, an increase in surface roughness, and a decrease in tensile strength; if the addition amount exceeds 10.0 mg / L, pinholes may be generated on the surface of the electrolytic copper foil, and the interaction of other additives may be disturbed.

[0040] In addition, when the above-mentioned additive C and additive D are used independently, they have significant effects. And when used in combination at appropriate concentrations, they can exert excellent synergistic effects in terms of coating uniformity, physical stability, and roughness reduction. First, when the two are used in combination, they have a dual inhibitory effect on crystal growth. Additive C inhibits the growth rate of surface metal crystals, while additive D prevents current concentration and blocks excessive deposition at specific positions, thus jointly forming a coating with a uniform microcrystalline structure. Thereby, an electrolytic copper foil with a flat surface and excellent durability can be prepared. Second, additive D uniformly adjusts the ion distribution in the electrolyte, while additive C controls the metal precipitation reaction rate, optimizing the current density and reaction uniformity in the electrolytic system. Thereby, a coating with a more precise thickness distribution and a more precise surface layer can be obtained.

[0041] In order to prevent oxidation on the surface of the electrolytic copper foil after the electrolytic copper foil electro-deposition process through the electrolyte, chromium anti-rust treatment is required. Chromium anti-rust solution uses chromium trioxide, but due to its strong toxicity and potential harm to the environment, glucose is added as a reducing agent at the same time. The concentration of chromium ions in the chromium anti-rust solution is 0.40 - 0.60 mg / L, the temperature of the anti-rust solution is 20 - 22 °C, the flow rate is 3 - 6 m 3 / hr, and the pH value is below 3.5. Finally, heat treatment is carried out in an oven at 50 - 65 °C to reduce the internal stress of the electrolytic copper foil, thereby reducing the degree of curling of the electrolytic copper foil. The electrolytic copper foil prepared by the above manufacturing method has a thickness of 3 - 5 μm, and an electrolytic copper foil with extremely low roughness and ultra-thin type suitable for the needs of the new generation of AI and communication industries can be manufactured.

[0042] Example 1

[0043] In the electrolyte solution in the electrolytic cell, an electric current is applied to a cathode roll and an anode plate with a hexagonal (honeycomb) regular structure on its surface that are spaced apart from each other. The electrolytic copper foil is electro-deposited on the surface of the cathode roll, and the Cr anti-rust treatment process is carried out through a roll-to-roll manufacturing process, and finally it is wound up for manufacturing. In order to eliminate stress, the manufactured electrolytic copper foil needs to be heat-treated in an oven at 60 °C for 12 hours. In the electrolyte used for manufacturing the above electrolytic copper foil, the copper ion concentration is 85.0 g / L, and the sulfate ion concentration is 115.0 g / L. The electrolyte temperature is 53.0 ± 1.0 °C, the current density is 37 A / dm², and the electrolyte flow rate is 55 m 3 / hr. The additives added to the electrolytic copper foil electrolyte are dissolved and stirred in each additive tank with ultrapure water.

[0044] The types and contents of the electrolyte additives used in this example are as follows:

[0045] Polishing agent (additive A) - bis(3-sulfopropyl) disulfide disodium salt 15.0 mg / L

[0046] Retarder (Additive B) – Hydroxyethyl cellulose 7.0 mg / L

[0047] Leveling agent (Additive C) – 2-Mercaptobenzimidazole 0.1 mg / L

[0048] Roughness regulator (Additive D) – Arylene ether oligomer 2.0 mg / L

[0049] In addition, the rust preventive liquid for chromium rust prevention treatment is prepared by reducing chromium trioxide with glucose, dissolving it together with ultrapure water and stirring. The Cr concentration is 0.55 mg / L, the temperature of the rust preventive liquid is 21.0 ± 1.0 °C, the flow rate is 4.2 m 3 / hr, and the pH value is maintained below 3.5.

[0050] Through the above manufacturing method and additives, an electrolytic copper foil with a thickness of 4 μm was manufactured.

[0051] Example 2

[0052] The types and contents of additives in the electrolytic copper foil electrolyte of this example are as follows:

[0053] Polishing agent (Additive A) – Sodium 3-(benzothiazolyl-2-mercapto) propanesulfonate 23.7 mg / L

[0054] Retarder (Additive B) – Polyvinyl alcohol 10.7 mg / L

[0055] Leveling agent (Additive C) – 2-Mercaptobenzimidazole 0.5 mg / L

[0056] Roughness regulator (Additive D) – Arylene ether oligomer 4.0 mg / L

[0057] Except for the different additives and addition amounts, the electrolytic copper foil was prepared by the same method as in Example 1.

[0058] Example 3

[0059] The types and contents of additives in the electrolytic copper foil electrolyte of this example are as follows:

[0060] Polishing agent (Additive A) – Sodium 3-(benzothiazolyl-2-mercapto)-propanesulfonate 32.5 mg / L

[0061] Retarder (Additive B) – Polyethylene glycol oleate 14.5 mg / L

[0062] Leveling agent (Additive C) – 2-Mercaptobenzimidazole 1.0 mg / L

[0063] Roughness regulator (Additive D) – Arylene ether oligomer 6.0 mg / L

[0064] An electrolytic copper foil was prepared in the same manner as in Example 1, except that the additives and their addition amounts were different.

[0065] Example 4

[0066] The types and contents of additives in the electrolytic copper foil electrolyte of this example were as follows:

[0067] Polishing agent (additive A) – Sodium 3-[(amino-iminomethyl)thio]-1-propanesulfonate 41.2 mg / L

[0068] Retarder (additive B) – Polyethylpropylene glycol 18.2 mg / L

[0069] Leveling agent (additive C) – 2-Mercaptobenzimidazole 1.5 mg / L

[0070] Roughness regulator (additive D) – Aryl ether oligomer 8.0 mg / L

[0071] An electrolytic copper foil was prepared in the same manner as in Example 1, except that the additives and their addition amounts were different.

[0072] Example 5

[0073] The types and contents of additives in the electrolytic copper foil electrolyte of this example were as follows:

[0074] Polishing agent (additive A) – Sodium 3-[(amino-iminomethyl)thio]-1-propanesulfonate 50.0 mg / L

[0075] Retarder (additive B) – Octyl polyalkoxy ether 22.0 mg / L

[0076] Leveling agent (additive C) – 2-Mercaptobenzimidazole 2.0 mg / L

[0077] Roughness regulator (additive D) – Aryl ether oligomer 10.0 mg / L

[0078] An electrolytic copper foil was prepared in the same manner as in Example 1, except that the additives and their addition amounts were different.

[0079] Comparative Example 1

[0080] This comparative example was basically the same as Example 1, except that a commercial flat anode plate was used as the anode plate.

[0081] Comparative Example 2

[0082] This comparative example was basically the same as Example 1, except that the addition amounts of the leveling agent (additive C) and the roughness regulator (additive D) were different.

[0083] The types and contents of additives in the electrolytic copper foil electrolyte of this comparative example were as follows:

[0084] Polishing agent (Additive A) - Disodium bis(3-sulfopropyl) disulfide 15.0 mg / L

[0085] Retarder (Additive B) - Hydroxyethyl cellulose 7.0 mg / L

[0086] Leveling agent (Additive C) - 2-Mercaptobenzimidazole 0.05 mg / L

[0087] Roughness regulator (Additive D) - Aryl ether oligomer 1.0 mg / L.

[0088] Comparative Example 3

[0089] This comparative example is basically the same as Example 2, except that the leveling agent (Additive C) is not added.

[0090] Comparative Example 4

[0091] This comparative example is basically the same as Example 3, except that the roughness regulator (Additive D) is not added.

[0092] Comparative Example 5

[0093] This comparative example is basically the same as Example 4, except that the leveling agent (Additive C) and the roughness regulator (Additive D) are not added.

[0094] Comparative Example 6

[0095] This comparative example is basically the same as Example 5, except that the addition amounts of the leveling agent (Additive C) and the roughness regulator (Additive D) are different.

[0096] The types and contents of the additives in the electrolytic copper foil electrolyte of this comparative example are as follows:

[0097] Polishing agent (Additive A) - Sodium 3-[(aminoiminomethyl)thio]-1-propanesulfonate 50.0 mg / L

[0098] Retarder (Additive B) - Octyl polyalkoxy ether 22.0 mg / L

[0099] Leveling agent (Additive C) - 2-Mercaptobenzimidazole 4.0 mg / L

[0100] Roughness regulator (Additive D) - Aryl ether oligomer 20.0 mg / L.

[0101] Comparative Example 7

[0102] This comparative example is basically the same as Example 5, except that a commercial flat anode plate is used as the anode plate.

[0103] Table 1 shows the types, contents of additives used in the preparation of copper foils in Examples 1-5 and Comparative Examples 1-7, and the anode plate structures. The thickness, surface roughness (Ra), tensile strength at room temperature after heat treatment, elongation at room temperature after heat treatment, and the appearance state of the electrolytic copper foils prepared in each case were measured and inspected, and the results are shown in Table 2.

[0104] Table 1 Types, addition amounts of additives used in each case, and anode plate structures

[0105]

[0106] Table 2 Performance test results of copper foils prepared in each case

[0107]

[0108] As can be seen from Table 1 and Table 2, the technical effects of the method of the present invention are obvious. In Examples 1 to 5, hexagonal (honeycomb-shaped) pattern anode plates were used, and additives C (leveling agent) and D (roughness regulator) were used within an appropriate concentration range, so that the surface roughness (Ra) of the electrolytic copper foil was maintained at an extremely low level of 0.05 to 0.10 μm. In addition, the tensile strength after heat treatment was 350 to 400 MPa, and the elongation was 3.0 to 4.5%, showing excellent mechanical properties, and the appearance state also formed a uniform coating without microdefects, and all were rated as good. This indicates that the honeycomb-shaped pattern anode plate improves the uniformity of current distribution by guiding the current distribution, reduces the roughness, and additives C and D make the surface uniform by refining the grains and relieving the internal stress in the structure, thereby improving the overall performance. In contrast, in Comparative Examples 1-7, due to the changes in the additive composition or anode plate structure, the phenomenon of performance degradation is obvious.

[0109] In Comparative Example 1, the additive composition was the same as that in Example 1, but a flat anode plate was used, and its surface roughness (Ra) was 0.20 μm, higher than that in Example 1 (0.10 μm); the tensile strength was 309 MPa, and the elongation was 5.0%, and the performance was relatively poor. Compared with Example 1, this indicates that the uneven current distribution results in a higher surface roughness (Ra), and it also proves that the honeycomb-shaped pattern structure has a significant effect on current control and roughness stabilization.

[0110] In Comparative Example 2, the addition amounts of additives C (leveling agent) and D (roughness regulator) were lower than the appropriate range, resulting in an increase in surface roughness (Ra) to 0.19 μm, a tensile strength of 312 MPa, and an elongation of 4.9%. The appearance state shows surface non-uniformity. This indicates that due to insufficient additives, grain control cannot be fully achieved, and there are limitations in ensuring roughness and coating uniformity.

[0111] In Comparative Example 3, Additive C (leveling agent) was not added. Its surface roughness (Ra) was 0.16 μm, the tensile strength was 329 MPa, and the elongation was 4.6%. The appearance state was good. This indicates that relying solely on the action of Additive D, the roughness, tensile strength, and appearance uniformity were guaranteed to a certain extent, but it was still slightly insufficient compared with Example 2, indicating certain limitations in the uniformity of metal grains.

[0112] In Comparative Example 4, Additive D (roughness regulator) was not added. Its surface roughness (Ra) was 0.18 μm, the tensile strength was 315 MPa, and the elongation was 4.8%. The appearance state was good. However, both the roughness value and the mechanical strength were lower than those in Example 3, which indicates that relying solely on the action of Additive C (leveling agent) alone, there are limitations in roughness control.

[0113] In Comparative Example 5, Additive C (leveling agent) and Additive D (roughness regulator) were not added. Its surface roughness (Ra) was 0.25 μm, reaching the highest level, the tensile strength was 288 MPa, being the lowest value. The elongation was 5.3%, but the appearance state showed surface non-uniformity. This indicates that in the case of the absence of both additives, the control of metal grains and the uniformity of the coating decreased severely, resulting in quality problems.

[0114] In Comparative Example 6, the addition amounts of Additive C (leveling agent) and Additive D (roughness regulator) exceeded the appropriate range. Its surface roughness (Ra) was 0.23 μm, the tensile strength was 301 MPa, and the elongation was 3.5%. Moreover, pinholes and surface non-uniformity problems appeared in the appearance. This indicates that excessive additives lead to interference or overreaction between metal grains.

[0115] The additive composition of Comparative Example 7 was the same as that of Example 5, but a flat anode plate was used. Its surface roughness (Ra) was 0.15 μm, the tensile strength was 332 MPa, and the elongation was 4.5%. The appearance state was good. However, although the same additives were used, its roughness was still higher than that in Example 5, which once again proves the significant influence of the anode plate structure on the coating uniformity and roughness reduction.

[0116] Based on the above results, it can be clearly proven that it is necessary to simultaneously apply the hexagonal (honeycomb-like) pattern anode plate structure, which is the core technology of the present invention, and appropriate concentrations of Additive C (leveling agent) and D (roughness regulator) to achieve extremely low roughness and excellent mechanical properties (tensile strength, elongation). The manufacturing method proposed by the present invention has significant technical advantages in the new generation of communication and AI industries with high-speed signal transmission and high-precision requirements, and is applicable to the production of high-performance electrolytic copper foils.

Claims

1. A method for manufacturing electrolytic copper foil applicable to the new generation of AI and communication industries, characterized in that, The implementation is specifically carried out according to the following steps: Step 1: Add raw copper into sulfuric acid, stir and dissolve it, then filter, and mix it with additives to obtain an electrolyte solution, and transfer the electrolyte solution to the electrolytic cell of the copper foil making machine; Step 2: Prepare a Cr anti-rust solution, filter it, and then transfer it to the chromium anti-oxidation tank of the copper foil making machine; Step 3: Apply current to the separately arranged cathode roller and anode plate, electro-deposit copper on the surface of the cathode roller, and carry out Cr anti-rust treatment through a roll-to-roll manufacturing process, then wind it up and bake it to obtain an electrolytic copper foil; Among them, the surface of the anode plate is provided with a honeycomb-like precise micro-pattern; In Step 1, the electrolyte solution is obtained by mixing and dissolving pure copper wire and sulfuric acid, and then adding additives; among them, the concentration of copper ions is 85 - 100 g / L, and the concentration of sulfate ions is 90 - 120 g / L; the additives include a polishing agent, a retarder, a leveling agent, and a roughness regulator; The polishing agent is one of bis(3-sulfopropyl)-disulfide disodium salt, 3-[(amino-iminomethyl)thio]-1-propane sulfonic acid sodium salt, 3-(benzothiazolyl-2-mercapto)-propane sulfonic acid sodium salt, and its addition amount is 15.0 - 50.0 mg / L; The retarder is one of hydroxyethyl cellulose, polyvinyl alcohol, polyethylene glycol oleate, and its addition amount is 7.0 - 22.0 mg / L; The leveling agent is 2-mercaptobenzimidazole, and its addition amount is 0.1 - 2.0 mg / L; The roughness regulator is an aryl ether oligomer, and its addition amount is 2.0 - 10.0 mg / L; The honeycomb-like precise micro-pattern on the anode plate is formed by an array of regular hexagon patterns. The side length of the regular hexagon is 10 μm, the distance between adjacent regular hexagons is 10 μm, and the pattern depth is 3 μm.

2. The manufacturing method of the electrolytic copper foil applicable to the new generation of AI and communication industries according to claim 1, characterized in that In Step 2, the preparation method of the Cr anti-rust solution is as follows: Add chromium trioxide and glucose into ultrapure water, stir and dissolve them to obtain it; among them, the concentration of chromium ions is 0.40 - 0.60 mg / L.

3. The manufacturing method of the electrolytic copper foil applicable to the new generation of AI and communication industries according to claim 1, characterized in that, During the electroplating process in Step 3, the temperature of the electrolyte is 45~55°C, the current density is 28~43 A / dm 2 , and the flow rate is 45~65 m 3 / hr.

4. The manufacturing method of the electrolytic copper foil applicable to the new generation of AI and communication industries according to claim 1, characterized in that, During the Cr anti-rust treatment process in Step 3, the temperature of the anti-rust liquid is 20~22°C, the flow rate is 3~6 m 3 / hr, and the pH value is below 3.

5.

5. The manufacturing method of the electrolytic copper foil applicable to the new generation of AI and communication industries according to claim 1, wherein The baking process in Step 3 is specifically: Carry out heat treatment in an oven at 50 - 65 °C.

6. The electrolytic copper foil applicable to the new-generation AI and communication industries is characterized in that, Prepared by the method described in any one of claims 1 - 5, with a thickness of 3 - 5 μm, a surface roughness Ra of 0.05 - 0.1 μm, a normal temperature tensile strength of 350 MPa - 400 MPa after heat treatment, and a normal temperature elongation of 3.0 - 4.5% after heat treatment.

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