Efficient and clean copper strip manufacturing process

Abstract

The invention relates to an efficient and clean copper strip manufacturing process, and relates to the technical field of metal material machining, and the efficient and clean copper strip manufacturing process comprises the steps that pre-degreasing alkaline soaking is conducted for preliminary oil removal; performing medium-pressure scrubbing with a silicon carbide brush; washing with 15-20MPa high-pressure water to remove residues; removing an oxide layer by using a mixed acid solution; spraying deionized water until the conductivity is less than or equal to 5 mu S / cm; performing multi-stage polishing; directional high-pressure spraying at 70 DEG C; performing passivation treatment to form a film; squeezing with an air knife and drying with heating air; and finally, winding of the high-cleanliness copper strip is completed, and full-process integrated treatment of cleaning, polishing and oxidation prevention is achieved. The method has the advantages that the surface cleanliness is optimized synergistically through dynamic degreasing agent switching and gradient polishing, matrix damage is inhibited and the compactness of a passive film is enhanced in combination with acid pickling and passivation linkage control, and a directional high-pressure spraying and low-residual-water-rate drying process is used as an auxiliary process; the comprehensive effects of efficient decontamination, low solvent consumption, high smoothness and long-acting anti-oxidation on the surface of the copper strip are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of metal material processing, and in particular to an efficient and clean copper strip manufacturing process. Background Art

[0002] The current copper strip surface treatment process generally adopts a combination of fixed processes and static parameters, such as using a single type of degreasing agent throughout the process, constant pressure polishing or fixed pickling time. Although this type of process can achieve basic cleaning and surface passivation, its adaptability and stability are significantly insufficient when faced with different oil pollution levels, material conditions or environmental protection requirements. In the prior art, there is a lack of a dynamic matching mechanism between the selection of degreasing agents and the amount of oil pollution, resulting in a waste of resources for low-oil copper strips due to excessive use of solvents, and high-oil copper strips are forced to be repeatedly treated due to incomplete cleaning, which indirectly increases the wastewater treatment load.

[0003] Existing polishing processes mostly rely on constant high-pressure operations. Although they can quickly remove surface contaminants, continuous high pressure can easily cause mechanical damage to the copper surface, forming microscopic scratches and becoming preferential diffusion channels for oxidation. The parameter designs of the pickling and passivation links often operate independently. When the pickling time is too long or the pH of the passivation solution is out of control, problems such as excessive corrosion of the substrate and loose film layers occur frequently, which directly weakens the surface protection performance. In addition, in order to meet high cleanliness requirements, traditional processes often sacrifice environmental protection. For example, high-solvent degreasers are used throughout the process or processing time is extended, resulting in solvent abuse and a surge in energy consumption. Relying solely on water-based degreasers makes it difficult to cope with complex oil pollution scenarios. Summary of the invention

[0004] The purpose of this application is to provide an efficient and clean copper strip production process, which solves the problems of resource waste, surface mechanical damage and environmental risks caused by parameter solidification and lack of coordination in multiple links in the existing copper strip surface treatment process.

[0005] In the first aspect, the present application provides an efficient and clean copper strip manufacturing process using the following technical solutions: An efficient and clean copper strip manufacturing process comprises the following steps: Pre-degreasing: immerse the copper strip in the pre-degreasing agent for 1-3 seconds; Abrasive brush cleaning: Use silicon carbide abrasive brush with degreasing agent to brush the surface of copper belt, the brushing pressure is 0.3-0.5MPa, and the degreasing temperature is 70±2℃; High-pressure washing: Use 15-20MPa high-pressure water gun for washing; Pickling: Use a mixture of sulfuric acid and nitric acid to remove the oxide layer; High-pressure spray flushing: flush with deionized water until the surface conductivity is ≤5μS / cm; Multi-stage grinding and polishing: Use 2000 mesh, 3000 mesh polishing brush and nylon brush to polish in sequence, and then brush and clean with high pressure spray at the same time; High-pressure directional spray of hot water: Deionized water at 70±2°C is used to directionally wash the surface of the copper strip; Passivation treatment: Spray or immerse the passivation solution; Pre-drying and squeezing with an air knife; Drying: Resistance heating to 125±5°C to evaporate the water vapor on the copper surface; Rewinding.

[0006] Preferably, the pre-degreasing agent is a water-based alkaline solution, which by mass percentage includes: 0.5-1.0% anionic surfactant, 0.2-0.8% alkaline pH regulator, and the balance is deionized water; The pH value of the pre-degreasing agent is 10-12, the temperature of the pre-degreasing is 40-50°C, and the traveling speed of the copper strip is 10-15 m / min.

[0007] The emulsification of the anionic surfactant quickly strips the floating oil on the surface. Sodium hydroxide in the pre-degreasing agent maintains an alkaline environment, destroys the binding force between the oil stain and the copper matrix, and at the same time avoids strong alkali corrosion of the copper material. The traveling speed of the copper strip is controlled at 10-15 m / min to ensure that the oil stain stripping efficiency matches the production line rhythm. The balance of the surfactant concentration and alkalinity avoids excessive oxidation of the copper strip surface.

[0008] Preferably, the degreasing agent is optionally a water-soluble degreasing agent or a semi-solvent degreasing agent, among which: The water-soluble degreasing agent by mass percentage includes: 3-5% anionic surfactant, 1-2% non-ionic surfactant, 2-4% sodium tripolyphosphate, and the balance is deionized water; The semi-solvent degreasing agent by mass percentage includes: 80-85% basic components of the water-soluble degreasing agent, 5-8% organic solvent, and the balance is deionized water.

[0009] A silicon carbide abrasive brush (hardness HRC55-60) is used to brush the surface of the copper strip under a pressure of 0.3-0.5 MPa, in combination with a water-soluble or semi-solvent degreasing agent. The water-soluble degreasing agent contains 3-5% anionic surfactant (such as sodium dodecylbenzenesulfonate) and 1-2% non-ionic surfactant (APG-08), enhancing the oil stain stripping by reducing the interfacial tension; the semi-solvent degreasing agent adds 5-8% ethylene glycol monobutyl ether to dissolve high-viscosity oil stains. The micro-cutting action of the abrasive brush destroys the oil film, and the degreasing agent penetrates to the interface to accelerate the dissolution of the oil stain. The type of degreasing agent is automatically switched according to the thickness of the oil stain (<50μm or ≥50μm) to avoid excessive use of the solvent.

[0010] Preferably, the sulfuric acid and nitric acid mixed acid solution by volume percentage includes: 5-8% sulfuric acid, 1-2% nitric acid, and the balance is deionized water. The pickling time in the pickling step is 10-15 seconds, and the acid solution circulation filtration accuracy is 50-55μm.

[0011] The oxide layer is removed by a mixed acid solution of sulfuric acid and nitric acid, and the pickling time is 10 - 15 seconds. Nitric acid accelerates the dissolution of copper oxide (CuO), and sulfuric acid provides an acidic environment and inhibits over-corrosion. The acid solution circulation filtration precision is 50 - 55 μm, and the copper powder generated by the reaction is removed in time. Nitric acid selectively dissolves CuO, and sulfuric acid inhibits the over-corrosion of the matrix copper (reaction formula: 3Cu + 8HNO3 → 3Cu(NO3)2 + 4H2O + 2NO↑). The filtration system blocks the re-deposition of copper powder and avoids surface pitting defects.

[0012] Preferably, the multi-stage grinding and polishing steps are specifically as follows: First-stage polishing: Use a 2000-mesh alumina abrasive polishing brush, the bristle hardness is HRC 55 - 60, the brush pressure is 0.2 - 0.3 MPa, and the copper strip traveling speed is 15 - 20 m / min; Second-stage polishing: Use a 3000-mesh diamond abrasive polishing brush, the bristle hardness is HRC 60 - 65, the brush pressure is 0.1 - 0.2 MPa, and the copper strip traveling speed is 10 - 15 m / min; Third-stage cleaning: Use a nylon soft brush and spray deionized water at 5 - 8 MPa to remove polishing debris; The surface roughness of the copper strip is controlled at 0.1 - 0.2 μm.

[0013] Rough polishing (2000 mesh) removes macroscopic scratches, fine polishing (3000 mesh) refines microscopic textures, and high-pressure water is used to directionally wash away polishing debris to avoid secondary scratching of the surface.

[0014] Preferably, in the hot water high-pressure directional spraying step, the spraying water pressure is 8 - 10 MPa, the spraying angle forms a 30° angle with the traveling direction of the copper strip, and the residual water rate on the copper strip surface is ≤ 3%.

[0015] Preferably, in the passivation treatment step, the passivation solution includes by mass percentage: Methylbenzotriazole 0.8 - 1.2%, sodium molybdate 3 - 5%, sodium tungstate 1 - 2%, silane coupling agent 0.5 - 1.0%, non-ionic surfactant 0.2 - 0.5%, and the balance is deionized water; In the passivation treatment step, the pH of the passivation solution is 4.5 - 5.0, and the flow rate of the passivation solution is 2.5 - 3.0 m / s.

[0016] The passivation solution contains 0.8 - 1.2% methylbenzotriazole (MBTA), 3 - 5% sodium molybdate and 1 - 2% sodium tungstate, and forms a composite passivation film under the condition of pH 4.5 - 5.0. The silane coupling agent enhances the bonding force between the passivation film and the copper substrate, and the non-ionic surfactant ensures uniform film formation. Molybdate and tungstate adsorb on the copper surface to form a dense oxide film; after hydrolysis, KH-550 generates silanol groups, which form Si-O-Cu covalent bonds with copper oxides, improving the adhesion of the film layer.

[0017] Preferably, in the air knife pre-drying and squeezing steps, the air knife wind speed is 50 - 60 m / s, and the squeezing is carried out using a squeezing roller made of a composite material of PTFE and silicon carbide, with a squeezing pressure of 1.0 - 1.5 MPa.

[0018] The low surface energy property of PTFE reduces the residual water film.

[0019] In summary, the present application includes at least one of the following beneficial technical effects: 1. By dynamically matching water-based or semi-solvent degreasers, the present application only enables the solvent component when the oil stain is heavy, avoiding the abuse of high-solvent formulations throughout the process. Compared with the existing method of fixedly using low-efficiency degreasers, the problems of frequent replenishment caused by insufficient adaptability and the hidden danger of excessive organic matter in wastewater are solved. 2. The present application adopts a brush pressure combination strategy of high first and then low. In the first stage, stubborn pollutants are broken, and in the second stage, the surface is finely trimmed. Compared with the traditional single high-pressure polishing process, it effectively reduces the mechanical damage of the abrasive to the substrate and avoids the risk of oxidation spread caused by scratches. 3. By limiting the pickling operation window and stabilizing the passivation reaction environment, the present application ensures the efficient removal of the oxide layer while inhibiting the over-corrosion of the substrate, and specifically solves the problems of loose film layer and ineffective protection caused by out-of-control time or pH value in the prior art.

[0020] 4. The present application differentially selects the degreasing system according to the degree of oil stain, maintaining both cleaning stability and minimizing the intervention of solvents to the greatest extent, breaking through the resource waste and environmental protection bottlenecks caused by the rigid use of a single degreaser in the traditional process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flowchart of the process of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following is a further detailed description of the present application in combination with the attached Figure 1 ,.

[0023] Example 1: Preparation of high-precision electronic copper foil Steps and parameters: Pre-degreasing: Pre-degreaser: Sodium dodecylbenzenesulfonate 0.8% + Sodium hydroxide 0.5% + Deionized water balance, pH 11.2; Temperature: 45°C, Travel speed of copper strip 12 m / min, Immersion time 2 s.

[0024] Abrasive brush cleaning: Degreaser selection: Water-soluble degreaser (Sodium dodecylbenzenesulfonate 4% + APG-08 1.5% + Sodium tripolyphosphate 3%); Brush pressure: 0.4 MPa, Degreasing temperature 70°C, Mesh number of silicon carbide abrasive brush 100 mesh.

[0025] Pickling: Pickling solution: Sulfuric acid 6% + Nitric acid 1.5% + Deionized water balance (by volume); Pickling time: 12 s, Filtration accuracy 50 μm.

[0026] Multi-stage polishing: First stage: 2000-mesh alumina brush (HRC 58, Brush pressure 0.25 MPa, Speed 18 m / min); Second stage: 3000-mesh diamond brush (HRC 62, Brush pressure 0.15 MPa, Speed 12 m / min); Third stage: Nylon brush with 6 MPa deionized water spray.

[0027] Passivation treatment: Passivation solution: MBTA 1.0% + Sodium molybdate 4% + Sodium tungstate 1.5% + KH-550 0.8% + APG-12 0.3%; pH 4.8, Flow rate of passivation solution 2.8 m / s, Passivation time 20 s.

[0028] Drying and winding: Air knife wind speed 55 m / s, Squeezing roller pressure 1.2 MPa, Drying temperature 125°C, Winding tension 60 N.

[0029] Example 2: Preparation of high corrosion-resistant transformer strip Steps and parameters: Pre-degreasing: Pre-degreaser: Sodium dodecylbenzenesulfonate 0.6% + Sodium hydroxide 0.3% + Deionized water balance, pH 10.5; Temperature: 48°C, Travel speed of copper strip 14 m / min, Immersion time 1.5 s.

[0030] Abrasive brush cleaning: Degreaser selection: Semi-solvent degreaser (Water-soluble basic component 83% + Ethylene glycol monobutyl ether 6%); Brush pressure: 0.45 MPa, Degreasing temperature 72°C, Mesh number of silicon carbide abrasive brush 120 mesh.

[0031] Pickling: Pickling solution: 7% sulfuric acid + 1.8% nitric acid + balance deionized water (by volume); Pickling time: 14 seconds, filtration accuracy 52 μm.

[0032] Multi-stage polishing: First stage: 2000-mesh alumina brush (HRC56, brush pressure 0.28 MPa, speed 16 m / min); Second stage: 3000-mesh diamond brush (HRC63, brush pressure 0.18 MPa, speed 13 m / min); Third stage: Nylon brush combined with 7 MPa deionized water spray.

[0033] Passivation treatment: Passivation solution: 1.1% MBTA + 4.5% sodium molybdate + 1.8% sodium tungstate + 0.7% KH-550 + 0.4% APG-120; pH 4.6, passivation solution flow rate 2.6 m / s, passivation time 25 seconds.

[0034] Drying and winding: Air knife wind speed 58 m / s, squeezing roller pressure 1.3 MPa, drying temperature 127 °C, winding tension 70 N.

[0035] Example 3: Preparation of low-cost general copper strip Steps and parameters: Pre-degreasing: Pre-degreasing agent: 0.5% sodium dodecylbenzenesulfonate + 0.2% sodium hydroxide + balance deionized water, pH 10.0; Temperature: 42 °C, copper strip traveling speed 10 m / min, immersion time 3 seconds.

[0036] Abrasive brush cleaning: Degreasing agent selection: Water-soluble degreasing agent (3% sodium dodecylbenzenesulfonate + 1.0% APG-08 + 2% sodium tripolyphosphate); Brush pressure: 0.35 MPa, degreasing temperature 68 °C, number of meshes of silicon carbide abrasive brush 80 meshes.

[0037] Pickling: Pickling solution: 5% sulfuric acid + 1.0% nitric acid + balance deionized water (by volume); Pickling time: 10 seconds, filtration accuracy 50 μm.

[0038] Multi-stage polishing: First stage: 2000-mesh alumina brush (HRC55, brush pressure 0.2 MPa, speed 15 m / min); Second level: 3000-mesh diamond brush (HRC60, brush pressure 0.1 MPa, speed 10 m / min); Third level: nylon brush combined with 5 MPa deionized water spray.

[0039] Passivation treatment: Passivation solution: 0.8% MBTA + 3% sodium molybdate + 1.0% sodium tungstate + 0.5% KH-550 + 0.2% APG-12; pH 5.0, passivation solution flow rate 3.0 m / s, passivation time 15 seconds.

[0040] Drying and winding: air knife wind speed 50 m / s, squeezing roller pressure 1.0 MPa, drying temperature 123 °C, winding tension 50 N.

[0041] Comparative example 1-1: Compared with Example 1, the difference is that: The anionic surfactant is removed from the pre-degreasing agent, and it only contains 0.5% sodium hydroxide + the balance of deionized water (pH 11.2); The remaining parameters are exactly the same as those in Example 1.

[0042] Comparative example 1-2: Compared with Example 1, the difference is that: The pickling time is extended to 25 seconds (originally 12 seconds); The remaining parameters are exactly the same as those in Example 1.

[0043] Comparative example 1-3: Compared with Example 1, the difference is that: The non-ionic surfactant (APG-08) in the water-soluble degreasing agent is replaced with an equal amount of sodium tripolyphosphate (i.e., 4% anionic surfactant + 4.5% sodium tripolyphosphate); The remaining parameters are exactly the same as those in Example 1.

[0044] Comparative example 1-4: Compared with Example 1, the difference is that: The hot water spray angle is adjusted to 90° (originally 30°); The remaining parameters are exactly the same as those in Example 1.

[0045] Comparative example 2-1: Compared with Example 2, the difference is that: The organic solvent content in the semi-solvent degreasing agent is reduced to 3% (originally 6%); The remaining parameters are exactly the same as those in Example 2.

[0046] Comparative example 2-2: Compared with Example 2, the differences are as follows: The pH of the passivation solution is adjusted to 3.8 (originally 4.6); The remaining parameters are exactly the same as those in Example 2.

[0047] Comparative Example 3-1: Compared with Example 3, the differences are as follows: The pressure of the first-stage polishing brush is set to 0.4 MPa (originally 0.2 MPa); The pressure of the second-stage polishing brush is set to 0.25 MPa (originally 0.1 MPa); The remaining parameters are exactly the same as those in Example 3.

[0048] Comparative Example 3-2: Compared with Example 3, the differences are as follows: The silane coupling agent is removed from the passivation solution, and the proportions of the remaining components remain unchanged; The remaining parameters are exactly the same as those in Example 3.

[0049] Experiment 1: Surface Performance Test Description of Experimental Procedures: Sample Preparation: Select a T2 copper strip with a thickness of 0.3 mm and a width of 200 mm, pre-coated with rolling oil (viscosity 35 mPa·s) on the surface, and the oil film thickness is 5 ± 0.5 μm.

[0050] Pre-degreasing: Prepare the pre-degreasing agent according to Example 1 (Example 1 uses 0.8% sodium dodecylbenzenesulfonate + 0.5% NaOH), and the anionic surfactant is removed in Comparative Example 1-1.

[0051] The soaking time is 2 seconds, the temperature is 45 °C, and the advancing speed of the copper strip is 12 m / min.

[0052] Abrasive Brush Cleaning: Silicon carbide abrasive brush (100 mesh), brush pressure 0.4 MPa, degreasing temperature 70 °C.

[0053] In Comparative Example 1-3, the non-ionic surfactant (APG-08) in the degreasing agent is replaced with an equal amount of sodium tripolyphosphate.

[0054] Pickling: Use a mixed acid solution of 6% sulfuric acid + 1.5% nitric acid, and the pickling time is 12 seconds (extended to 25 seconds in Comparative Example 1-2).

[0055] The acid solution circulation filtration accuracy is 50 μm.

[0056] Multi-stage Polishing: First stage: 2000-mesh alumina brush (brush pressure 0.25 MPa, speed 18 m / min); Second stage: 3000-mesh diamond brush (brush pressure 0.15 MPa, speed 12 m / min); Third stage: nylon brush combined with 6 MPa deionized water spray (adjust the spray angle to 90° in Comparative Examples 1-4).

[0057] Passivation and drying: The passivation solution is formulated according to Example 1 (MBTA 1.0% + sodium molybdate 4%), and the passivation time is 20 seconds; The air knife wind speed is 55 m / s, the squeezing roller pressure is 1.2 MPa, and the drying temperature is 125 °C.

[0058] Testing method: Oil residue rate: detected by the weighing method according to ISO10545-13; Surface corrosion rate: calculated by the weight loss method (change in the thickness of the copper strip after pickling); Stubborn oil removal rate: high-viscosity grease (80 mPa·s) is manually coated, and the remaining area after cleaning is statistically counted; Surface residual water rate: the water content on the surface before drying is measured by an infrared moisture meter.

[0059] Experimental data table: Table 1: Comparison results of surface properties in Experiment 1

[0060] Data description: Comparative Example 1-1 (removing anionic surfactant): The oil residue rate increased to 0.42 mg / m 2 (8.4 times that of Example 1), proving the key role of anionic surfactant in emulsifying and dispersing oil.

[0061] Comparative Example 1-2 (extending the pickling time to 25 seconds): The surface corrosion rate soared to 0.83 μm / min (4 times that of Example 1), and over-pickling led to over-corrosion of the copper substrate.

[0062] Comparative Example 1-3 (replacing the surfactant of the degreaser): The stubborn oil removal rate dropped to 63.4% (98.2% in Example 1), and the non-ionic surfactant (APG-08) has an irreplaceable effect on removing high-viscosity grease.

[0063] Comparative Example 1-4 (spray angle 90°): The surface residual water rate increased to 9.2% (2.8% in Example 1), and the 30° spray angle optimizes the drainage path through the water flow shear force, while vertical spraying causes droplet retention.

[0064] Experimental summary: After removing the anionic surfactant in Comparative Example 1-1, the oil residue rate increased from 0.05 mg / m 2 to 0.42 mg / m2 。An anionic surfactant disperses grease into micron-sized emulsion droplets through the molecular structures of its hydrophilic and hydrophobic groups. An alkaline environment accelerates the saponification reaction, and effective emulsification cannot be achieved solely relying on sodium hydroxide.

[0065] In Comparative Examples 1-2, the pickling time was extended to 25 seconds, and the corrosion rate increased from 0.21 μm / min to 0.83 μm / min. The synergistic effect of nitric acid and sulfuric acid rapidly dissolves the oxide layer in the initial stage, but after the time limit, the acid solution continuously erodes the copper substrate, resulting in an increase in surface roughness and affecting the subsequent polishing effect.

[0066] When 90° spraying was used in Comparative Example 1-4, the residual water rate increased to 9.2% (2.8% in Example 1). The 30° spraying angle guides the liquid to flow directionally along the copper strip surface through the water flow shear force, reducing droplet rebound and retention. Angle deviation leads to a decrease in drainage efficiency and an increase in drying energy consumption by about 30%. Experiment 2: Corrosion resistance test Description of experimental steps: Sample preparation: Select a T3 copper strip with a thickness of 0.5 mm and a width of 150 mm, pre-coated with transformer oil (viscosity 120 mPa·s) on the surface, and the oil film thickness is 8 ± 1 μm.

[0067] Pre-degreasing: Prepare the pre-degreasing agent according to Example 2 (sodium dodecylbenzenesulfonate 0.6% + NaOH 0.3%), temperature 48°C, and the copper strip traveling speed 14 m / min.

[0068] Abrasive brush cleaning: Use a semi-solvent degreasing agent (water-soluble basic component 83% + ethylene glycol monobutyl ether 6%), and in Comparative Example 2-1, the organic solvent content was reduced to 3%.

[0069] Silicon carbide abrasive brush (120 mesh), brush pressure 0.45 MPa, degreasing temperature 72°C.

[0070] Pickling: A mixed acid solution of 7% sulfuric acid + 1.8% nitric acid, pickling time 14 seconds, filtration accuracy 52 μm.

[0071] Multi-stage polishing: First stage: 2000-mesh alumina brush (brush pressure 0.28 MPa, speed 16 m / min); Second stage: 3000-mesh diamond brush (brush pressure 0.18 MPa, speed 13 m / min); Third stage: Nylon brush combined with 7 MPa deionized water spraying.

[0072] Passivation treatment: The passivation solution was formulated according to Example 2 (MBTA 1.1% + sodium molybdate 4.5% + sodium tungstate 1.8%). In Comparative Example 2-2, the pH of the passivation solution was adjusted to 3.8 (originally 4.6).

[0073] The passivation time was 25 seconds and the flow rate of the passivation solution was 2.6 m / s.

[0074] Drying and testing: The air knife wind speed was 58 m / s, the pressure of the squeezing roller was 1.3 MPa, and the drying temperature was 127 °C.

[0075] Salt spray resistance test: Neutral salt spray test was carried out according to ASTM B117 standard; Porosity of the passivation film: Calculated by fitting through electrochemical impedance spectroscopy (EIS); Humid heat aging: The discoloration time of the copper strip surface was tested under the environment of 85 °C / 85% RH.

[0076] Experimental data table: Table 2: Comparison results of corrosion resistance in Experiment 2 Group Salt spray resistance time (hours) Porosity of passivation film (%) Discoloration time under damp heat aging (hours) Example 2 518 3.6 1020 Comparative Example 2-1 275 9.8 610 Comparative Example 2-2 143 12.4 320 Data description: Comparative Example 2-1 (organic solvent content 3%): The salt spray resistance time decreased from 518 hours to 275 hours. Insufficient organic solvent concentration led to the residue of high-viscosity oil stains, and the local defects of the passivation film increased.

[0077] Comparative Example 2-2 (pH of the passivation solution 3.8): The porosity of the passivation film increased to 12.4% (3.6% in Example 2). Too strong acidity destroyed the stability of the passivation solution, and the film-forming compactness decreased significantly.

[0078] Experimental summary: In Comparative Example 2-1, the solvent content was reduced from 6% to 3%, and the salt spray resistance time was shortened by 47%. The dissolving ability of ethylene glycol monobutyl ether for high-viscosity oil stains decreased sharply with the decrease of concentration. The residual grease hindered film formation during the passivation stage, resulting in the preferential occurrence of local corrosion.

[0079] In Comparative Example 2-2, when the pH was reduced to 3.8, the porosity of the passivation film increased to 12.4%. Molybdate and tungstate formed a stable heteropolyacid structure in a weakly acidic environment (pH 4.5 - 5.0). When the pH was too low, hydrolysis was aggravated and microcracks appeared in the passivation film.

[0080] The salt spray time of Example 2 was 518 hours and the humid heat aging time was 1020 hours, which relied on the coordinated control of degreasing - pickling - passivation. Any parameter deviation in any link would trigger a chain reaction: the residual oil stains accelerated the failure of the passivation film, and the increase in film porosity accelerated the oxidation of the copper substrate.

[0081] Experiment 3: Surface quality test Description of experimental steps: Sample preparation: Select an H65 brass strip with a thickness of 0.4 mm and a width of 180 mm, pre-coat the surface with a general-purpose lubricating grease (viscosity 45 mPa·s), and the oil film thickness is 6 ± 0.8 μm.

[0082] Pre-degreasing: Configure the pre-degreasing agent according to Example 3 (sodium dodecylbenzenesulfonate 0.5% + NaOH 0.2%), temperature 42 °C, and the copper strip traveling speed is 10 m / min.

[0083] Abrasive brush cleaning: Use a water-soluble degreasing agent (sodium dodecylbenzenesulfonate 3% + APG-08 1.0%), brush pressure 0.35 MPa, and degreasing temperature 68 °C.

[0084] Pickling: A mixed acid solution of 5% sulfuric acid + 1.0% nitric acid, pickling time 10 seconds, and filtration accuracy 50 μm.

[0085] Multi-stage polishing: First stage: 2000-mesh alumina brush (brush pressure 0.2 MPa, speed 15 m / min); Second stage: 3000-mesh diamond brush (brush pressure 0.1 MPa, speed 10 m / min); Third stage: Nylon brush combined with 5 MPa deionized water spraying.

[0086] Comparative Example 3-1: The brush pressure of the first-stage polishing is increased to 0.4 MPa, and the brush pressure of the second stage is increased to 0.25 MPa.

[0087] Passivation treatment: The passivation solution is formulated according to Example 3 (MBTA 0.8% + sodium molybdate 3% + KH-550 0.5%). In Comparative Example 3-2, the silane coupling agent (KH-550) is removed.

[0088] Passivation time 15 seconds, passivation solution flow rate 3.0 m / s.

[0089] Drying and testing: The air knife wind speed is 50 m / s, the squeezing roller pressure is 1.0 MPa, and the drying temperature is 123 °C.

[0090] Surface roughness Ra: Measured by a white light interferometer (take the average value of 3 points); Adhesion of the passivation film: Tested by the cross-cut method (ASTM D3359), and evaluated by the proportion of the peeling area; Damp heat resistance: Record the appearance time of surface oxidation spots in an environment of 85 °C / 85% RH.

[0091] Experimental data table: Table 3: Comparison results of surface quality and passivation performance in Experiment 3 Group Surface roughness Ra (μm) Adhesion of passivation film (peeling area %) Damp heat resistance time (hours) Example 3 0.16 5.2 850 Comparative Example 3-1 0.37 18.6 420 Comparative Example 3-2 0.19 32.4 290 Data description: Comparative example 3-1 (polishing pressure increased): The surface roughness Ra increased from 0.16 μm to 0.37 μm. The brush pressure exceeded the limit, causing the alumina abrasive to scratch the substrate, and the micro-scratches increased.

[0092] Comparative example 3-2 (silane coupling agent removed): The peeling area of the passivation film adhesion increased from 5.2% to 32.4%. KH-550 enhances the film-substrate bonding through the Si-O-Cu bond. After its absence, the interfacial bonding force decreased significantly.

[0093] Experiment description: In comparative example 3-1, the polishing brush pressure increased from 0.2 MPa to 0.4 MPa, and the surface roughness Ra increased to 0.37 μm. The alumina abrasive penetrated the oxide film on the surface of the copper strip under high pressure and directly cut the substrate metal. The increase in the density of micro-scratches led to enhanced light scattering and a decrease in the apparent surface finish.

[0094] After removing KH-550 in comparative example 3-2, the peeling area of the passivation film adhesion increased to 32.4%. The Si-OH groups generated by the hydrolysis of the silane coupling agent form covalent bonds with the hydroxyl groups on the copper surface and crosslink with the MBTA molecules in the passivating agent. After its absence, the film layer and the substrate only rely on physical adsorption and are prone to delamination in a humid and hot environment.

[0095] In Example 3, the flat surface with Ra = 0.16 μm enables the passivation solution to spread evenly, and the film thickness fluctuation is less than 5%. The high roughness in comparative example 3-1 results in local thinning of the passivation film (<50 nm). The exposed areas of the copper substrate are preferentially oxidized during the humid and hot test, and the corrosion resistance time is shortened by 50%.

[0096] The embodiments of this specific implementation manner are all preferred embodiments of this application, and do not limit the protection scope of this application accordingly. The same components are represented by the same reference numerals. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. An efficient and clean copper strip production process, characterized in that: The following steps are involved: Pre-degreasing: immerse the copper strip in the pre-degreasing agent for 1-3 seconds; Abrasive brush cleaning: Use silicon carbide abrasive brush with degreasing agent to brush the surface of copper belt, the brushing pressure is 0.3-0.5MPa, and the degreasing temperature is 70±2℃; High-pressure washing: Use 15-20MPa high-pressure water gun for washing; Pickling: Use a mixture of sulfuric acid and nitric acid to remove the oxide layer; High-pressure spray flushing: flush with deionized water until the surface conductivity is ≤5μS / cm; Multi-stage grinding and polishing: Use 2000 mesh, 3000 mesh polishing brush and nylon brush to polish in sequence, and then brush and clean with high-pressure spray at the same time; Hot water high pressure directional spraying: 70±2℃ deionized water directional flushes the copper strip surface; Passivation treatment: spray or soak in passivation liquid; Air knife pre-drying and squeezing; Drying: Heat the resistor to 125±5℃ to evaporate the water vapor on the copper surface; Roll up.

2. The efficient and clean copper strip manufacturing process according to claim 1, characterized in that: The pre-degreasing agent is a water-based alkaline solution, which includes, by mass percentage, 0.5-1.0% of anionic surfactant, 0.2-0.8% of alkaline pH regulator, and the balance is deionized water; The pH value of the pre-degreasing agent is 10-12, the pre-degreasing temperature is 40-50° C., and the traveling speed of the copper strip is 10-15 m / min.

3. The efficient and clean copper strip manufacturing process according to claim 1, characterized in that: The degreasing agent is optionally a water-soluble degreasing agent or a semi-solvent degreasing agent, wherein: The water-soluble degreasing agent comprises, by mass percentage, 3-5% anionic surfactant, 1-2% nonionic surfactant, 2-4% sodium tripolyphosphate, and the balance is deionized water; The semi-solvent degreasing agent comprises, by mass percentage, 80-85% of a water-soluble degreasing agent basic component, 5-8% of an organic solvent, and the balance being deionized water.

4. The efficient and clean copper strip manufacturing process according to claim 1, characterized in that: The mixed acid solution of sulfuric acid and nitric acid comprises, by volume percentage, 5-8% sulfuric acid, 1-2% nitric acid, and the balance is deionized water. The pickling time in the pickling step is 10-15 seconds, and the acid solution circulation filtration accuracy is 50-55 μm.

5. The efficient and clean copper strip manufacturing process according to claim 1, characterized in that: The multi-stage grinding and polishing steps are as follows: First-level polishing: Use a 2000-mesh aluminum oxide abrasive polishing brush with a bristle hardness of 55-60 HRC, a brush pressure of 0.2-0.3MPa, and a copper belt travel speed of 15-20m / min; Second level polishing: use 3000 mesh diamond abrasive polishing brush, bristle hardness HRC 60-65, brush pressure 0.1-0.2MPa, copper belt travel speed 10-15m / min; Third-level cleaning: Use a nylon soft brush and 5-8MPa deionized water spray to remove polishing debris; The surface roughness of the copper strip is controlled at 0.1-0.2μm.

6. The efficient and clean copper strip manufacturing process according to claim 1, characterized in that: In the hot water high-pressure directional spraying step, the spraying water pressure is 8-10 MPa, the spraying angle is 30° with the traveling direction of the copper strip, and the residual water rate on the surface of the copper strip is ≤3%.

7. The efficient and clean copper strip manufacturing process according to claim 1, characterized in that: The passivation solution in the passivation treatment step comprises, by mass percentage: Tolyltriazole 0.8-1.2%, sodium molybdate 3-5%, sodium tungstate 1-2%, silane coupling agent 0.5-1.0%, nonionic surfactant 0.2-0.5%, the balance is deionized water; In the passivation treatment step, the pH of the passivation solution is 4.5-5.0, and the flow rate of the passivation solution is 2.5-3.0 m / s.

8. The efficient and clean copper strip manufacturing process according to claim 1, characterized in that: In the air knife pre-drying and squeezing steps, the air knife wind speed is 50-60m / s, and squeezing is performed using a squeezing roller made of a composite material of PTFE and silicon carbide, and the squeezing pressure is 1.0-1.5MPa.

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