PET copper foil, chemical plating preparation method and application thereof

Abstract

The invention belongs to the technical field of PET copper foil preparation, and particularly relates to a PET copper foil, a chemical plating preparation method and application of the PET copper foil, and the preparation method comprises the following specific steps: S1, pretreatment: firstly, cleaning a PET film, and in the cleaning process, sequentially carrying out weak base washing, primary water washing, acid washing and secondary water washing; s2, activating treatment: carrying out palladium deposition treatment on the cleaned PET film by adopting a copper oxide copper dissolving mode; s3, chemical copper deposition: transferring the PET film into a chemical copper plating tank for chemical copper deposition, wherein the copper plating tank is filled with a copper plating solution; the surface of the PET film is subjected to wetting treatment to remove loose particles on the surface, then the surface of the PET film is subjected to spraying cleaning, the electrolyte adopts a specific additive to be matched with an existing solution, growth of copper crystal grains can be effectively controlled, and therefore a compact plating layer is obtained. The copper foil has high tensile strength, high elongation and excellent mechanical properties.

Description

Technical Field

[0001] The invention belongs to the technical field of PET copper foil preparation, in particular to a PET copper foil, a chemical plating preparation method and application thereof. Background Art

[0002] PET copper foil is a composite copper foil material that uses polyethylene terephthalate polymer film as the substrate, and deposits a copper layer on the surface of the PET film.

[0003] With the rapid development of new energy vehicles, the requirements for batteries are getting higher and higher. Lithium battery copper foil is currently used as the negative electrode current collector of lithium batteries. Due to the high amount of copper used, the material cost is greatly affected by the copper price, and there are bottlenecks in battery safety and energy density. Power battery manufacturers have the motivation and demand to find new alternative materials for cost, safety and energy density considerations. PET copper foil is based on the characteristics of saving about 2 / 3 of raw material costs, higher safety and energy density, and conforms to the downstream development law. It can replace traditional copper foil to a certain extent. The advantages of PET composite copper foil are 1μm copper foil + 4.5μm PET film + 1μm copper foil, and it has the high tensile strength and high ductility of traditional copper foil, and has ultra-thin performance;

[0004] In the existing copper foil preparation technology, the ratio of copper sulfate and sulfuric acid in the plating solution of the electrolyte determines the production quality of the copper foil. The existing ratio of the plating solution components leads to insufficient copper deposition speed and copper layer density.

[0005] To this end, the present invention provides a PET copper foil, a chemical plating preparation method and applications thereof. Summary of the invention

[0006] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a PET copper foil and chemical plating preparation method described in the present invention, the specific steps of the preparation method are as follows:

[0008] S1. Pretreatment: First, the PET film is cleaned, and the cleaning process is followed by weak alkali washing, primary water washing, acid washing and secondary water washing;

[0009] S2, activation treatment: copper oxide dissolving method is used to treat the cleaned PET film with palladium precipitation;

[0010] S3, chemical copper deposition: transferring the PET film to a chemical copper plating tank for chemical copper deposition, wherein the copper plating tank is filled with a copper plating solution;

[0011] S4, cleaning: the surface of the PET film is wetted to remove loose particles on the surface, and then the surface of the PET film is sprayed and cleaned to further remove surface pollutants, and then the residue on the surface of the film is cut off by high-pressure water flow, and the surface of the PET film is sprayed and rinsed on both sides to remove impurities generated during the cleaning process;

[0012] S5. Drying: Remove moisture through hot air drying device. The PET film needs to be dried multiple times to ensure that the finished product is obtained after thorough drying.

[0013] Preferably, the copper plating solution in S3 comprises the following components: 70-100 g / L copper sulfate; 140-200 g / L sulfuric acid; 70-100 mg / L chloride ions and additives, and the reaction temperature needs to be maintained between 20-28°C.

[0014] The electrolyte used for composite copper foil includes electroplating solution and electroplating additives. The main plating solution is an aqueous solution of sulfuric acid and copper sulfate. In order to achieve its glossiness, trace amounts of chloride ions and brighteners are added to the solution. The brightener contains alkyl sulfonates to enhance the wetting effect of the solution. As the electroplating proceeds, the copper ions in the solution will be continuously consumed. The copper ion replenishment method is to use electroplating grade materials to oxidize copper to prepare the electrolyte. After the electrolyte is filtered at multiple stages, the corresponding brightener is added and then injected into the electroplating tank. The copper foil is produced at high temperature and high current density. After the copper foil is made, 2-4g / L chromic anhydride is used for electrolytic protection, the copper foil is used as the cathode, the total current is 2-4A, the time is 2-5 seconds, and the copper foil used by customers is made. According to the preparation principle of electrolytic copper foil, the electrolyte needs heat exchange to cool or heat the plating solution. The electroplating temperature is basically controlled at 35-60℃, the current density is 30-80A / dm2, and copper sulfate is added to the copper plating solution to deposit a layer of copper metal on the surface of the conductive object. This process can improve the conductivity, wear resistance and corrosion resistance of the material.

[0015] Preferably, the specific process of alkali washing in S1 is that the PET film is pre-degreased and dewaxed using an alkali washing solution in a spray alkali washing tank, the alkali washing solution includes 5-10g / L of degreasing powder, and the process temperature is 40-50°C to enhance the hydrophilicity of the film; the specific process of acid washing is that the PET film is immersed in a mixed solution of 200-250g / L chromic acid and 200-250g / L sulfuric acid at room temperature for acid washing and roughening; the primary water washing and the secondary water washing both use pure water to wash the PET film, the PET film is placed in a washing tank containing an alkaline solution, and the solution is heated to a certain temperature to wash the PET film, which can remove pollutants such as ink and colloid on the surface of the PET film, thereby improving the reuse rate of the film and the product quality.

[0016] Preferably, the palladium precipitation treatment in S2 requires that during the electroplating process, as the copper ions are consumed, the acidity of the plating solution will also increase, and the consumed copper ions are replenished by dissolving copper oxide powder. The solution circulates back and forth to continuously dissolve copper oxide to keep the solution concentration stable. By performing palladium precipitation treatment on the PET film, the bonding strength between the PET film and other materials can be enhanced, which helps to improve the mechanical properties and durability of the final product.

[0017] Preferably, the additive in the copper plating solution is sodium dodecylbenzene sulfonate, which can enhance the wettability of the solution. Sodium dodecylbenzene sulfonate is usually added to the copper plating solution as a surfactant. The surfactant can improve the wetting and dispersing properties of the plating solution and help the plating solution better wet the surface of the object to be plated.

[0018] Preferably, the cleaning process requires the use of pure water to clean the PET film strip. The PET film will be exposed to various chemicals and impurities during the manufacturing and processing process. These residues may affect its final performance and purity. The purpose of using pure water for cleaning is to remove these contaminants and ensure the cleanliness and quality of the PET film.

[0019] Preferably, the copper plating tank in S3 includes a tank liquid circulation system, a filtration system, a cooling system and an aeration system. Adding a tank liquid circulation system to the copper plating tank is usually used to improve the efficiency and quality of the electroplating process. The circulation system can help maintain the uniformity of the temperature and chemical composition of the tank liquid, ensuring that the thickness and quality of the electroplated layer are more consistent.

[0020] Preferably, the specific steps of chemical copper deposition in S3 are: the PET film horizontally enters the copper plating tank, the rolled film enters the plating tank from the squeeze roller, and immediately enters the solution, and an electrochemical reaction occurs under the action of the reducing agent. Chemical copper deposition can be used on non-conductive polymer substrates such as PET. Chemical copper deposition can deposit a layer of copper on the pore wall. This is because PET itself is not conductive and needs to be given conductivity through chemical copper deposition.

[0021] Preferably, the copper plating solution is cooled by spraying to stabilize the solution temperature at 20-28° C. Spraying liquid cooling can ensure that the solution temperature is stable, thereby obtaining a more uniform and dense plating layer.

[0022] Preferably, an application of PET copper foil, the advantages of PET composite copper foil are high tensile strength, high ductility and ultra-thin performance. PET copper foil is mainly used as a negative electrode collector material in lithium batteries, and is also used in the packaging and manufacturing of various electronic products.

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

[0024] 1. A PET copper foil, chemical plating preparation method and application thereof described in the present invention. The electrolyte of the present invention adopts a specific additive in combination with an existing solution, which can effectively control the growth of copper grains, thereby obtaining a dense coating. The composite copper foil prepared by the electrolyte and electroplating production process of the present invention has high tensile strength, high elongation, and excellent mechanical properties of the copper foil.

[0025] 2. In order to solve the problem of incomplete cleaning during the preparation process of PET copper foil in the prior art, the present application achieves comprehensive cleaning of the PET film by setting up pretreatment steps of weak alkali washing, primary water washing, acid washing and secondary water washing in sequence; by performing wet treatment, spray cleaning, high-pressure water flow cutting residues and double-sided spray rinsing after the cleaning step, the loose particles and contaminants on the surface of the PET film are effectively removed. Multi-step cleaning can ensure the purity of the PET film in subsequent processes, which is conducive to improving the preparation quality of the PET copper foil in the subsequent process.

[0026] 3. In order to solve the problem of insufficient stability of chemical copper plating solutions in the prior art, the present application sets a copper plating solution of a specific composition, including 70-100 g / L copper sulfate, 140-200 g / L sulfuric acid, 70-100 mg / L chloride ions and additives (such as sodium dodecylbenzene sulfonate), and uses spray refrigeration to stabilize the solution temperature between 20-28°C, thereby achieving stability and good wettability of the copper plating solution. At the same time, in the palladium precipitation treatment, the consumed copper ions are replenished by dissolving copper oxide powder, so that the solution circulates back and forth, continuously dissolving copper oxide, and maintaining a stable solution concentration.

[0027] 4. By setting up a copper plating tank with a tank liquid circulation system, a filtering system, a cooling system and an aeration system, the uniformity and stability of the copper plating solution are achieved, and the problems of uneven solution and easy deterioration in the copper plating process in the prior art are solved. In the chemical copper deposition step, the PET film enters the copper plating tank horizontally, and the rolled film enters the plating tank from the squeeze roller and immediately enters the solution. An electrochemical reaction occurs under the action of the reducing agent, ensuring the uniform deposition of copper. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below in conjunction with the accompanying drawings.

[0029] Figure 1 is a flow chart of the preparation method of the present invention;

[0030] Figure 2 It is a flow chart of the preparation process of the present invention. DETAILED DESCRIPTION

[0031] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0032] Embodiment 1:

[0033] like Figure 1 to Figure 2 As shown, a PET copper foil and chemical plating preparation method described in an embodiment of the present invention, the specific steps of the preparation method are as follows:

[0034] S1. Pretreatment: First, the PET film is cleaned, and the cleaning process is followed by weak alkali washing, primary water washing, acid washing and secondary water washing;

[0035] S2, activation treatment: copper oxide dissolving method is used to treat the cleaned PET film with palladium precipitation;

[0036] S3, chemical copper deposition: transferring the PET film to a chemical copper plating tank for chemical copper deposition, wherein the copper plating tank is filled with a copper plating solution;

[0037] S4, cleaning: the surface of the PET film is wetted to remove loose particles on the surface, and then the surface of the PET film is sprayed and cleaned to further remove surface pollutants, and then the residue on the surface of the film is cut off by high-pressure water flow, and the surface of the PET film is sprayed and rinsed on both sides to remove impurities generated during the cleaning process;

[0038] S5. Drying: Remove moisture through hot air drying device. The PET film needs to be dried multiple times to ensure that the finished product is obtained after thorough drying.

[0039] The copper plating solution in S3 includes the following components: 70-100g / L copper sulfate; 140-200g / L sulfuric acid; 70-100mg / L chloride ions and additives, and the reaction temperature needs to be maintained between 20-28°C. During operation, copper sulfate is added to the copper plating solution to deposit a layer of copper metal on the surface of the conductive object. This process can improve the conductivity, wear resistance and corrosion resistance of the material. Sulfuric acid is added to the copper plating solution to adjust the pH value and concentration of the solution to optimize the electroplating effect. By controlling the pH value, the quality of the electroplated layer can be improved. Adding chloride ions to the copper plating solution can improve the quality and adhesion of the coating. Chloride ions, as complexing agents, can help stabilize copper ions and promote their reduction process at the cathode. At the same time, chloride ions can also increase the conductivity of the solution, thereby improving the electroplating speed and uniformity.

[0040] In S1, the specific process of alkali washing is that the PET film is pre-degreased and dewaxed with an alkali washing solution in a spray alkali washing tank, the alkali washing solution includes 5-10g / L of degreasing powder, and the process temperature is 40-50°C to enhance the hydrophilicity of the film; the specific process of acid washing is that the PET film is immersed in a mixed solution of 200-250g / L chromic acid and 200-250g / L sulfuric acid at room temperature for acid washing and roughening; the primary water washing and the secondary water washing both use pure water to wash the PET film. During operation, the PET film is placed in a washing tank containing an alkaline solution, and the solution is heated to a certain temperature to wash the PET film, which can remove ink and colloid on the surface of the PET film. Such pollutants can be removed, which can improve the recycling rate of the film and the product quality. At the same time, alkaline washing has the advantages of high safety, low toxicity, low cost, simple process technology, etc., and the wastewater treatment is relatively simple. After the alkaline solution on the surface of the PET film is washed away, the PET film is acid-washed. Acid washing can effectively remove organic pollutants and certain inorganic substances on the surface of the PET film, and destroy the structure of these pollutants through chemical action, making it easy to remove them from the surface of the film. Acid washing can also improve the surface energy of the PET film, increase its hydrophilicity or lipophilicity, thereby improving the bonding strength with other materials and the adhesion of the coating. The PET film is then washed twice to wash away the acidic solution on the surface of the PET.

[0041] The palladium deposition treatment described in S2 requires that during the electroplating process, as the copper ions are consumed, the acidity of the plating solution will also increase. The consumed copper ions are replenished by dissolving copper oxide powder. The solution circulates back and forth to continuously dissolve copper oxide to keep the solution concentration stable. During operation, the PET film is subjected to palladium deposition treatment to enhance the bonding strength between the PET film and other materials, which helps to improve the mechanical properties and durability of the final product, and can form a conductive layer on the PET film, which is very beneficial for electronic applications that require conductive properties. At the same time, the palladium deposition layer can serve as a protective layer to improve the chemical stability of the PET film, enabling it to resist corrosion by some chemical substances, and can also change the surface properties of the PET film, thereby improving its processing performance before printing, coating or bonding.

[0042] The additive in the copper plating solution is sodium dodecylbenzene sulfonate, which can enhance the wettability of the solution. When working, sodium dodecylbenzene sulfonate is usually added to the copper plating solution as a surfactant. The surfactant can improve the wetting and dispersing properties of the plating solution, help the plating solution to better wet the surface of the object to be plated, promote the uniform deposition of metal ions, thereby improving the quality and adhesion of the coating. In addition, the surfactant can also stabilize the bubbles in the plating solution, reduce the formation of pores, and optimize the microstructure of the coating.

[0043] The cleaning process described in S4 requires the use of pure water to clean the PET film strip. During operation, the PET film will be exposed to various chemicals and impurities during the manufacturing and processing process. These residues may affect its final performance and purity. The purpose of using pure water for cleaning is to remove these pollutants and ensure the cleanliness and quality of the PET film. Pure water has low conductivity and less dissolved solids, so it can more effectively rinse away ions and organic matter on the membrane surface without introducing new pollution.

[0044] The copper-plating tank described in S3 includes a tank liquid circulation system, a filtration system, a cooling system and an aeration system. When working, adding a tank liquid circulation system to the copper-plating tank is usually used to improve the efficiency and quality of the electroplating process. The circulation system can help maintain the uniformity of the temperature and chemical composition of the tank liquid, ensure that the thickness and quality of the electroplating layer are more consistent, and the circulation system can also reduce the accumulation of impurities in the tank liquid, extend the service life of the tank liquid, and help comply with environmental emission standards. Through circulation filtration, suspended particles such as metal hydroxides can be removed to maintain the cleanliness of the electroplating solution. Adding a filtration system to the copper-plating tank can effectively remove suspended solid particles, oxides and other impurities from the electroplating solution. If these impurities remain in the electroplating solution, they will affect the uniformity and adhesion of the coating. Adding a cooling system to the copper-plating tank can maintain a suitable reaction rate at a lower temperature, thereby optimizing the reaction conditions and effectively avoiding the occurrence of side reactions caused by excessively high temperatures or affecting the purity of the product. Adding an aeration system to the copper-plating tank can increase the oxygen content in the solution, ensure that metal ions such as copper ions are reduced and deposited faster, and also help maintain the chemical stability of the solution and prevent the aggregation of precipitates.

[0045] The specific steps of chemical copper deposition in S3 are as follows: the PET film enters the copper plating tank horizontally, the rolled film enters the plating tank from the squeeze roller, and immediately enters the solution. An electrochemical reaction occurs under the action of the reducing agent. During operation, chemical copper deposition can be used on non-conductive polymer substrates such as PET. Chemical copper deposition can deposit a layer of copper on the hole wall. This is because PET itself is not conductive and needs to be given conductivity through chemical copper deposition. The copper layer formed by chemical copper deposition can serve as the basis for subsequent electroplating processes to help achieve thicker copper layer deposition, thereby enhancing conductivity and mechanical strength. At the same time, chemical copper deposition helps to improve the bonding strength between the copper layer and the PET substrate, which ensures the reliability of flexible circuit boards and batteries during bending and folding.

[0046] The copper plating solution adopts spray cooling to stabilize the solution temperature at 20-28°C. During operation, spray liquid cooling can ensure the stability of the solution temperature, thereby obtaining a more uniform and dense coating. At the same time, the stable solution temperature helps to increase the electroplating speed and reduce production interruptions caused by temperature fluctuations, thereby improving the overall production efficiency. Compared with traditional cooling methods, spray cooling systems are usually more efficient, can better control heat transfer, and reduce energy consumption.

[0047] The copper oxide powder is added into a tank containing a copper sulfate solution, and the solution is circulated and dissolved by a pump to replenish the consumed copper ions. After multi-stage filtration, the plating solution enters the copper plating solution circulation system to maintain the copper plating solution concentration of 80-120g / L, the sulfuric acid content of 75-100g / L, and the chloride ion content of 50-100mg / L; the above solution is added into the basic copper sulfate copper plating solution, and the copper foil cathode adopts a conductive roller method, and the PET film with a layer of copper is magnetically controlled to transmit the current through the conductive roller, so that the copper is evenly plated on the PET film; 1μm copper layer is plated on the top and bottom.

[0048] Embodiment 2:

[0049] like Figure 1 to Figure 2 As shown, a PET copper foil and chemical plating preparation method described in an embodiment of the present invention, the specific steps of the preparation method are as follows:

[0050] S1. Pretreatment: First, the PET film is cleaned, and the cleaning process is followed by weak alkali washing, primary water washing, acid washing and secondary water washing;

[0051] S2, activation treatment: copper oxide dissolving method is used to treat the cleaned PET film with palladium precipitation;

[0052] S3, chemical copper deposition: transferring the PET film to a chemical copper plating tank for chemical copper deposition, wherein the copper plating tank is filled with a copper plating solution;

[0053] S4, cleaning: the surface of the PET film is wetted to remove loose particles on the surface, and then the surface of the PET film is sprayed and cleaned to further remove surface pollutants, and then the residue on the surface of the film is cut off by high-pressure water flow, and the surface of the PET film is sprayed and rinsed on both sides to remove impurities generated during the cleaning process;

[0054] S5. Drying: Remove moisture through hot air drying device. The PET film needs to be dried multiple times to ensure that the finished product is obtained after thorough drying.

[0055] The copper plating solution in S3 includes the following components: 70-100g / L copper sulfate; 140-200g / L sulfuric acid; 70-100mg / L chloride ions and additives, and the reaction temperature needs to be maintained between 20-28°C. During operation, copper sulfate is added to the copper plating solution to deposit a layer of copper metal on the surface of the conductive object. This process can improve the conductivity, wear resistance and corrosion resistance of the material. Sulfuric acid is added to the copper plating solution to adjust the pH value and concentration of the solution to optimize the electroplating effect. By controlling the pH value, the quality of the electroplated layer can be improved. Adding chloride ions to the copper plating solution can improve the quality and adhesion of the coating. Chloride ions, as complexing agents, can help stabilize copper ions and promote their reduction process at the cathode. At the same time, chloride ions can also increase the conductivity of the solution, thereby improving the electroplating speed and uniformity.

[0056] In S1, the specific process of alkali washing is that the PET film is pre-degreased and dewaxed with an alkali washing solution in a spray alkali washing tank, the alkali washing solution includes 5-10g / L of degreasing powder, and the process temperature is 40-50°C to enhance the hydrophilicity of the film; the specific process of acid washing is that the PET film is immersed in a mixed solution of 200-250g / L chromic acid and 200-250g / L sulfuric acid at room temperature for acid washing and roughening; the primary water washing and the secondary water washing both use pure water to wash the PET film. During operation, the PET film is placed in a washing tank containing an alkaline solution, and the solution is heated to a certain temperature to wash the PET film, which can remove ink and colloid on the surface of the PET film. Such pollutants can be removed, which can improve the recycling rate of the film and the product quality. At the same time, alkaline washing has the advantages of high safety, low toxicity, low cost, simple process technology, etc., and the wastewater treatment is relatively simple. After the alkaline solution on the surface of the PET film is washed away, the PET film is acid-washed. Acid washing can effectively remove organic pollutants and certain inorganic substances on the surface of the PET film, and destroy the structure of these pollutants through chemical action, making it easy to remove them from the surface of the film. Acid washing can also improve the surface energy of the PET film, increase its hydrophilicity or lipophilicity, thereby improving the bonding strength with other materials and the adhesion of the coating. The PET film is then washed twice to wash away the acidic solution on the surface of the PET.

[0057] The palladium deposition treatment described in S2 requires that during the electroplating process, as the copper ions are consumed, the acidity of the plating solution will also increase. The consumed copper ions are replenished by dissolving copper oxide powder. The solution circulates back and forth to continuously dissolve copper oxide to keep the solution concentration stable. During operation, the PET film is subjected to palladium deposition treatment to enhance the bonding strength between the PET film and other materials, which helps to improve the mechanical properties and durability of the final product, and can form a conductive layer on the PET film, which is very beneficial for electronic applications that require conductive properties. At the same time, the palladium deposition layer can serve as a protective layer to improve the chemical stability of the PET film, enabling it to resist corrosion by some chemical substances, and can also change the surface properties of the PET film, thereby improving its processing performance before printing, coating or bonding.

[0058] The additive in the copper plating solution is sodium dodecylbenzene sulfonate, which can enhance the wettability of the solution. When working, sodium dodecylbenzene sulfonate is usually added to the copper plating solution as a surfactant. The surfactant can improve the wetting and dispersing properties of the plating solution, help the plating solution to better wet the surface of the object to be plated, promote the uniform deposition of metal ions, thereby improving the quality and adhesion of the coating. In addition, the surfactant can also stabilize the bubbles in the plating solution, reduce the formation of pores, and optimize the microstructure of the coating.

[0059] The cleaning process described in S4 requires the use of pure water to clean the PET film strip. During operation, the PET film will be exposed to various chemicals and impurities during the manufacturing and processing process. These residues may affect its final performance and purity. The purpose of using pure water for cleaning is to remove these pollutants and ensure the cleanliness and quality of the PET film. Pure water has low conductivity and less dissolved solids, so it can more effectively rinse away ions and organic matter on the membrane surface without introducing new pollution.

[0060] The copper-plating tank described in S3 includes a tank liquid circulation system, a filtration system, a cooling system and an aeration system. When working, adding a tank liquid circulation system to the copper-plating tank is usually used to improve the efficiency and quality of the electroplating process. The circulation system can help maintain the uniformity of the temperature and chemical composition of the tank liquid, ensure that the thickness and quality of the electroplating layer are more consistent, and the circulation system can also reduce the accumulation of impurities in the tank liquid, extend the service life of the tank liquid, and help comply with environmental emission standards. Through circulation filtration, suspended particles such as metal hydroxides can be removed to maintain the cleanliness of the electroplating solution. Adding a filtration system to the copper-plating tank can effectively remove suspended solid particles, oxides and other impurities from the electroplating solution. If these impurities remain in the electroplating solution, they will affect the uniformity and adhesion of the coating. Adding a cooling system to the copper-plating tank can maintain a suitable reaction rate at a lower temperature, thereby optimizing the reaction conditions and effectively avoiding the occurrence of side reactions caused by excessively high temperatures or affecting the purity of the product. Adding an aeration system to the copper-plating tank can increase the oxygen content in the solution, ensure that metal ions such as copper ions are reduced and deposited faster, and also help maintain the chemical stability of the solution and prevent the aggregation of precipitates.

[0061] The specific steps of chemical copper deposition in S3 are as follows: the PET film enters the copper plating tank horizontally, the rolled film enters the plating tank from the squeeze roller, and immediately enters the solution. An electrochemical reaction occurs under the action of the reducing agent. During operation, chemical copper deposition can be used on non-conductive polymer substrates such as PET. Chemical copper deposition can deposit a layer of copper on the hole wall. This is because PET itself is not conductive and needs to be given conductivity through chemical copper deposition. The copper layer formed by chemical copper deposition can serve as the basis for subsequent electroplating processes to help achieve thicker copper layer deposition, thereby enhancing conductivity and mechanical strength. At the same time, chemical copper deposition helps to improve the bonding strength between the copper layer and the PET substrate, which ensures the reliability of flexible circuit boards and batteries during bending and folding.

[0062] The copper plating solution adopts spray cooling to stabilize the solution temperature at 20-28°C. During operation, spray liquid cooling can ensure the stability of the solution temperature, thereby obtaining a more uniform and dense coating. At the same time, the stable solution temperature helps to increase the electroplating speed and reduce production interruptions caused by temperature fluctuations, thereby improving the overall production efficiency. Compared with traditional cooling methods, spray cooling systems are usually more efficient, can better control heat transfer, and reduce energy consumption.

[0063] The electrolyte mainly includes copper sulfate, sulfuric acid, chloride ions and copper plating additives, among which the additives are single-component additives. The main ingredient, polyethyleneimine alkyl salt (PN), is a derivative of polyethyleneimine quaternization, a high molecular cationic polymer, which acts in the acid copper plating solution as both a leveling agent and a low-zone brightener. It plays a coordinated and harmonious comprehensive role in the entire acid copper plating additive. In order to obtain fine crystallization, high gloss, and high-leveling mirror effect in acid copper plating, three types of additives such as brightener, leveling agent and surfactant must be added. The main ingredients are polyethyleneimine alkyl salt: 10-15mg / L; sodium dodecylbenzene sulfonate: 20-30mg / L.

[0064] Embodiment three:

[0065] like Figure 1 to Figure 2 As shown, a PET copper foil and chemical plating preparation method described in an embodiment of the present invention, the specific steps of the preparation method are as follows:

[0066] S1. Pretreatment: First, the PET film is cleaned, and the cleaning process is followed by weak alkali washing, primary water washing, acid washing and secondary water washing;

[0067] S2, activation treatment: copper oxide dissolving method is used to treat the cleaned PET film with palladium precipitation;

[0068] S3, chemical copper deposition: transferring the PET film to a chemical copper plating tank for chemical copper deposition, wherein the copper plating tank is filled with a copper plating solution;

[0069] S4, cleaning: the surface of the PET film is wetted to remove loose particles on the surface, and then the surface of the PET film is sprayed and cleaned to further remove surface pollutants, and then the residue on the surface of the film is cut off by high-pressure water flow, and the surface of the PET film is sprayed and rinsed on both sides to remove impurities generated during the cleaning process;

[0070] S5. Drying: Remove moisture through hot air drying device. The PET film needs to be dried multiple times to ensure that the finished product is obtained after thorough drying.

[0071] The copper plating solution in S3 includes the following components: 70-100g / L copper sulfate; 140-200g / L sulfuric acid; 70-100mg / L chloride ions and additives, and the reaction temperature needs to be maintained between 20-28°C. During operation, copper sulfate is added to the copper plating solution to deposit a layer of copper metal on the surface of the conductive object. This process can improve the conductivity, wear resistance and corrosion resistance of the material. Sulfuric acid is added to the copper plating solution to adjust the pH value and concentration of the solution to optimize the electroplating effect. By controlling the pH value, the quality of the electroplated layer can be improved. Adding chloride ions to the copper plating solution can improve the quality and adhesion of the coating. Chloride ions, as complexing agents, can help stabilize copper ions and promote their reduction process at the cathode. At the same time, chloride ions can also increase the conductivity of the solution, thereby improving the electroplating speed and uniformity.

[0072] In S1, the specific process of alkali washing is that the PET film is pre-degreased and dewaxed with an alkali washing solution in a spray alkali washing tank, the alkali washing solution includes 5-10g / L of degreasing powder, and the process temperature is 40-50°C to enhance the hydrophilicity of the film; the specific process of acid washing is that the PET film is immersed in a mixed solution of 200-250g / L chromic acid and 200-250g / L sulfuric acid at room temperature for acid washing and roughening; the primary water washing and the secondary water washing both use pure water to wash the PET film. During operation, the PET film is placed in a washing tank containing an alkaline solution, and the solution is heated to a certain temperature to wash the PET film, which can remove ink and colloid on the surface of the PET film. Such pollutants can be removed, which can improve the recycling rate of the film and the product quality. At the same time, alkaline washing has the advantages of high safety, low toxicity, low cost, simple process technology, etc., and the wastewater treatment is relatively simple. After the alkaline solution on the surface of the PET film is washed away, the PET film is acid-washed. Acid washing can effectively remove organic pollutants and certain inorganic substances on the surface of the PET film, and destroy the structure of these pollutants through chemical action, making it easy to remove them from the surface of the film. Acid washing can also improve the surface energy of the PET film, increase its hydrophilicity or lipophilicity, thereby improving the bonding strength with other materials and the adhesion of the coating. The PET film is then washed twice to wash away the acidic solution on the surface of the PET.

[0073] The palladium deposition treatment described in S2 requires that during the electroplating process, as the copper ions are consumed, the acidity of the plating solution will also increase. The consumed copper ions are replenished by dissolving copper oxide powder. The solution circulates back and forth to continuously dissolve copper oxide to keep the solution concentration stable. During operation, the PET film is subjected to palladium deposition treatment to enhance the bonding strength between the PET film and other materials, which helps to improve the mechanical properties and durability of the final product, and can form a conductive layer on the PET film, which is very beneficial for electronic applications that require conductive properties. At the same time, the palladium deposition layer can serve as a protective layer to improve the chemical stability of the PET film, enabling it to resist corrosion by some chemical substances, and can also change the surface properties of the PET film, thereby improving its processing performance before printing, coating or bonding.

[0074] The additive in the copper plating solution is sodium dodecylbenzene sulfonate, which can enhance the wettability of the solution. When working, sodium dodecylbenzene sulfonate is usually added to the copper plating solution as a surfactant. The surfactant can improve the wetting and dispersing properties of the plating solution, help the plating solution to better wet the surface of the object to be plated, promote the uniform deposition of metal ions, thereby improving the quality and adhesion of the coating. In addition, the surfactant can also stabilize the bubbles in the plating solution, reduce the formation of pores, and optimize the microstructure of the coating.

[0075] The cleaning process described in S4 requires the use of pure water to clean the PET film strip. During operation, the PET film will be exposed to various chemicals and impurities during the manufacturing and processing process. These residues may affect its final performance and purity. The purpose of using pure water for cleaning is to remove these pollutants and ensure the cleanliness and quality of the PET film. Pure water has low conductivity and less dissolved solids, so it can more effectively rinse away ions and organic matter on the membrane surface without introducing new pollution.

[0076] The copper-plating tank described in S3 includes a tank liquid circulation system, a filtration system, a cooling system and an aeration system. When working, adding a tank liquid circulation system to the copper-plating tank is usually used to improve the efficiency and quality of the electroplating process. The circulation system can help maintain the uniformity of the temperature and chemical composition of the tank liquid, ensure that the thickness and quality of the electroplating layer are more consistent, and the circulation system can also reduce the accumulation of impurities in the tank liquid, extend the service life of the tank liquid, and help comply with environmental emission standards. Through circulation filtration, suspended particles such as metal hydroxides can be removed to maintain the cleanliness of the electroplating solution. Adding a filtration system to the copper-plating tank can effectively remove suspended solid particles, oxides and other impurities from the electroplating solution. If these impurities remain in the electroplating solution, they will affect the uniformity and adhesion of the coating. Adding a cooling system to the copper-plating tank can maintain a suitable reaction rate at a lower temperature, thereby optimizing the reaction conditions and effectively avoiding the occurrence of side reactions caused by excessively high temperatures or affecting the purity of the product. Adding an aeration system to the copper-plating tank can increase the oxygen content in the solution, ensure that metal ions such as copper ions are reduced and deposited faster, and also help maintain the chemical stability of the solution and prevent the aggregation of precipitates.

[0077] The specific steps of chemical copper deposition in S3 are as follows: the PET film enters the copper plating tank horizontally, the rolled film enters the plating tank from the squeeze roller, and immediately enters the solution. An electrochemical reaction occurs under the action of the reducing agent. During operation, chemical copper deposition can be used on non-conductive polymer substrates such as PET. Chemical copper deposition can deposit a layer of copper on the hole wall. This is because PET itself is not conductive and needs to be given conductivity through chemical copper deposition. The copper layer formed by chemical copper deposition can serve as the basis for subsequent electroplating processes to help achieve thicker copper layer deposition, thereby enhancing conductivity and mechanical strength. At the same time, chemical copper deposition helps to improve the bonding strength between the copper layer and the PET substrate, which ensures the reliability of flexible circuit boards and batteries during bending and folding.

[0078] The copper plating solution adopts spray cooling to stabilize the solution temperature at 20-28°C. During operation, spray liquid cooling can ensure the stability of the solution temperature, thereby obtaining a more uniform and dense coating. At the same time, the stable solution temperature helps to increase the electroplating speed and reduce production interruptions caused by temperature fluctuations, thereby improving the overall production efficiency. Compared with traditional cooling methods, spray cooling systems are usually more efficient, can better control heat transfer, and reduce energy consumption.

[0079] The copper oxide dissolving method is adopted. During the electroplating process, as the copper ions are consumed, the acidity of the plating solution will also increase. The consumed copper ions are replenished by dissolving copper oxide powder. The solution circulates back and forth to continuously dissolve copper oxide to maintain a stable solution concentration. Sodium dodecylbenzene sulfonate is added to the additive to enhance the wettability of the solution. Spray cooling is used to stabilize the solution temperature at 20-28°C.

[0080] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A PET copper foil and chemical plating preparation method, characterized in that: The specific steps of the preparation method are as follows: S1. Pretreatment: First, the PET film is cleaned, and the cleaning process is followed by weak alkali washing, primary water washing, acid washing and secondary water washing; S2, activation treatment: copper oxide dissolving method is used to treat the cleaned PET film with palladium precipitation; S3, chemical copper deposition: transferring the PET film to a chemical copper plating tank for chemical copper deposition, wherein the copper plating tank is filled with a copper plating solution; S4, cleaning: the surface of the PET film is wetted to remove loose particles on the surface, and then the surface of the PET film is sprayed and cleaned to further remove surface pollutants, and then the residue on the surface of the film is cut off by high-pressure water flow, and the surface of the PET film is sprayed and rinsed on both sides to remove impurities generated during the cleaning process; S5. Drying: Remove moisture through hot air drying device. The PET film needs to be dried multiple times to ensure that the finished product is obtained after thorough drying.

2. A PET copper foil and chemical plating preparation method according to claim 1, characterized in that: The copper plating solution in S3 includes the following components: 70-100 g / L copper sulfate; 140-200 g / L sulfuric acid; 70-100 mg / L chloride ions and additives, and the reaction temperature needs to be maintained between 20-28°C.

3. The method for preparing PET copper foil by chemical plating according to claim 1, characterized in that: The specific process of alkali washing in S1 is that the PET film is pre-degreased and dewaxed using an alkali washing solution in a spray alkali washing tank, wherein the alkali washing solution includes 5-10 g / L of degreasing powder and a process temperature of 40-50°C to enhance the hydrophilicity of the film; the specific process of acid washing is that the PET film is immersed in a mixed solution of 200-250 g / L of chromic acid and 200-250 g / L of sulfuric acid at room temperature for acid washing and roughening; the primary water washing and the secondary water washing both use pure water to clean the PET film.

4. The method for preparing PET copper foil by chemical plating according to claim 1, characterized in that: The palladium precipitation treatment in S2 requires that during the electroplating process, as copper ions are consumed, the acidity of the plating solution will also increase. The consumed copper ions are replenished by dissolving copper oxide powder. The solution circulates back and forth to continuously dissolve copper oxide to keep the solution concentration stable.

5. A PET copper foil and chemical plating preparation method according to claim 2, characterized in that: The additive in the copper plating solution is sodium dodecylbenzene sulfonate, which can enhance the wettability of the solution.

6. A PET copper foil and chemical plating preparation method according to claim 1, characterized in that: The cleaning process in S4 requires the use of pure water to clean the PET film strip.

7. The method for preparing PET copper foil by chemical plating according to claim 1, characterized in that: The copper plating tank in S3 includes a tank liquid circulation system, a filtering system, a cooling system and an aeration system.

8. The method for preparing PET copper foil by chemical plating according to claim 1, characterized in that: The specific steps of chemical copper deposition in S3 are as follows: the PET film is horizontally placed in the copper plating tank, the rolled film is placed in the plating tank from the squeeze roller, and immediately enters the solution, where an electrochemical reaction occurs under the action of the reducing agent.

9. A PET copper foil and chemical plating preparation method according to claim 2, characterized in that: The copper plating solution is cooled by spraying to stabilize the solution temperature at 20-28°C.

10. An application of PET copper foil, characterized in that: PET composite copper foil has the advantages of high tensile strength, high ductility and ultra-thin performance. PET copper foil is mainly used as a negative electrode current collector material in lithium batteries, and is also used in the packaging and manufacturing of a variety of electronic products.

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