A high-performance copper alloy for electronic materials and a method for manufacturing the same

Abstract

The present application relates to copper alloy preparation technical field, specifically to a kind of high-performance copper alloy for electronic material and preparation method thereof.The present application includes the following steps: preparation processing copper alloy material, preparation etching liquid, preparation biological base hydrophobic coating liquid and preparation high-performance copper alloy for electronic material.Cu-Al-Fe-Si alloy system is used to prepare processing copper alloy material in the present application, which not only prepares the substrate of copper alloy, but also makes the processing copper alloy material prepared in the subsequent etching by the synergistic design of material composition and organizational structure, so that the etching liquid can uniformly react on the surface of the processing copper alloy material, avoiding uneven etching caused by composition segregation, thereby improving the uniformity of coating when adhering.The surface of the copper alloy material obtained after etching finally has optimized physical roughness and chemical activity, so that the biological base coating can be firmly adhered to the surface of the copper alloy material after etching, thereby obtaining high-performance superhydrophobic coating.

Description

Technical Field

[0001] This invention relates to the field of copper alloy preparation technology, and specifically to a high-performance copper alloy for electronic materials and its preparation method. Background Technology

[0002] With the rapid development of semiconductor technology and the continuous improvement of chip integration and power density, extremely stringent requirements have been placed on the materials used in key processes such as chip manufacturing, packaging, and heat dissipation. Copper and its alloys, with their excellent electrical and thermal conductivity, play a crucial role in interconnects and packaging substrates for semiconductor chips. However, copper alloys are prone to oxidation, corrosion, or surface degradation in humid, corrosive, or high-temperature environments, severely affecting the reliability and lifespan of semiconductor chips. To improve their durability, a hydrophobic coating is often applied to the surface to form a protective barrier against water and oxygen, and to resist contamination.

[0003] In existing technologies, the preparation of superhydrophobic coatings mostly relies on a two-step method: first, a micro-nano rough structure is constructed on the metal surface through chemical etching, anodizing, or laser treatment, followed by coating with a low surface energy material. However, this method has the following limitations: First, the inhomogeneity of the composition and microstructure of the copper alloy substrate itself leads to differences in the surface reaction rate during etching, making it difficult to form a uniform micro-nano structure, which in turn affects the uniformity of coating adhesion; second, the surface etching products produced by traditional etching solutions such as strong acids, strong alkalis, or heavy metal oxidants have weak bonding with the substrate, which easily leads to structural collapse or coating peeling, affecting the coating durability.

[0004] Therefore, there is an urgent need to develop a high-performance copper alloy and its preparation process for electronic materials, which can achieve high-strength adhesion and long-term durability of superhydrophobic coatings, so as to be suitable for electronic materials in harsh environments, especially for semiconductor wafer applications. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a high-performance copper alloy for electronic materials and a method for preparing the same.

[0006] A method for preparing a high-performance copper alloy for electronic materials includes the following steps:

[0007] High-purity copper, pure iron sheets, high-purity aluminum ingots, and crystalline silicon were added to a graphite crucible, and the mixture was evacuated to a vacuum of 5 × 10⁻⁶. -3 Pa, purged with argon as a protective atmosphere, heated to 1240-1260℃, held for 10-15 minutes, and electromagnetically stirred to obtain a molten alloy liquid;

[0008] Molten alloy liquid is poured onto a water-cooled copper roller rotating at 2000-2100 rpm for melt quenching to obtain copper alloy sheets with a thickness of 1-2 mm.

[0009] Anneal at 400-440℃ under argon protection for 30-35 minutes to eliminate internal stress and obtain the copper alloy sheet to be treated. Then, use 800-grit, 1200-grit, 1600-grit and 2000-grit sandpaper to grind the surface of the copper alloy sheet to be treated for 10-12 minutes in sequence to finally obtain the treated copper alloy material.

[0010] The copper alloy material was subjected to oxygen plasma cleaning at a power of 50-80W, a treatment time of 45-60 seconds, and an oxygen flow rate of 15-20 sccm to obtain activated copper alloy material.

[0011] The activated copper alloy material is completely immersed in the etching solution for etching to obtain the etched copper alloy substrate.

[0012] The etched copper alloy substrate is immersed in a preheated bio-based hydrophobic coating liquid and then cured to obtain a high-performance copper alloy for electronic materials.

[0013] The contents of copper, aluminum, iron and silicon, by mass percentage, are as follows: copper: 92-94 wt%, aluminum: 5-6 wt%, iron: 0.5-1 wt%, and silicon: 0.5-1 wt%.

[0014] Furthermore, the specific preparation method of the etching solution includes the following steps:

[0015] Add L-tyrosine powder to triethanolamine at a ratio of 1g:(150-160)mL, stir continuously at 100-200rpm and heat to 40-45℃ for 20-25 minutes until L-tyrosine is evenly dispersed and a viscous pale yellow solution is formed. Stop heating, continue stirring and cool to room temperature of 22-24℃ to obtain tyrosine-triethanolamine premix.

[0016] Citric acid and ethanol solution were mixed at a ratio of 1 g to (400-410) mL and stirred until dissolved. The pH of the system was then adjusted to 7.5-8.0 to obtain citric acid-ethanol buffer solution.

[0017] Under magnetic stirring at 300-400 rpm, add citric acid ethanol buffer to tyrosine-triethanolamine premix, control the temperature at 30-35℃, keep stirring, and add sodium periodate solution to obtain etching solution.

[0018] Furthermore, the specific preparation method of the bio-based hydrophobic coating liquid includes the following steps:

[0019] Weigh 15-20 parts by weight of carnauba wax, heat it in a water bath to 82-86℃, and magnetically stir it at 200-220 rpm for 15-20 minutes. Then add 2-3 parts by weight of rosin glycerol ester and continue stirring for 5-7 minutes. After that, add 3-4 parts by weight of stearic acid and stir evenly to obtain the wax phase.

[0020] Mix 58-60 parts by weight of anhydrous ethanol, 10-12 parts by weight of ethyl acetate and 3-5 parts by weight of turpentine oil at 300-400 rpm for 5-10 minutes to obtain a functional solvent;

[0021] Weigh 0.5-1 parts by weight of lecithin and add it to the above functional solvent. Stir for 10 minutes until completely dissolved, and then add hydrophobic nano silica in steps to obtain a nano silica dispersion.

[0022] Add 2-2.5 parts by weight of β-carotene to the nano-silica dispersion, stir at 100-120 rpm for 5-10 minutes, heat in a water bath to 65-70℃, and add dropwise to the above wax phase while stirring at 800-850 rpm. Raise the temperature to 84-86℃, increase the stirring speed to 1200-1300 rpm, stir and emulsify for 15-20 minutes, cool naturally in a water bath to 40-45℃, and mature by shaking at 60-80 rpm for 30-35 minutes. Filter the product through a 200-mesh nylon screen to obtain the bio-based hydrophobic coating liquid.

[0023] Furthermore, the specific steps for immersing the activated copper alloy material in the etching solution for etching are as follows:

[0024] Pour the prepared etching solution into a polytetrafluoroethylene etching tank, completely immerse the activated copper alloy material in the etching solution, soak for 10-15 minutes while magnetically stirring at 100-150 rpm, then remove it and immerse it in a cleaner containing 0.1M sodium thiosulfate solution for 30 seconds. Then clean it three times each with deionized water and anhydrous ethanol, and blow it dry with high-purity nitrogen to obtain the etched copper alloy substrate.

[0025] Furthermore, the specific steps for immersing and curing the etched copper alloy substrate in a preheated bio-based hydrophobic coating solution are as follows:

[0026] The etched copper alloy substrate is preheated to 70-75℃. The prepared bio-based hydrophobic coating solution is preheated in a water bath at 40-45℃ before use. The etched copper alloy substrate is immersed in the preheated bio-based hydrophobic coating solution at a speed of 3cm / s for 30-40s. Then it is pulled up at a speed of 0.5-1mm / s. Finally, it is left to stand at 40-45℃ for 15-20 minutes for pre-curing. Then the temperature is raised to 86-90℃ and held for 5-8 minutes. Finally, it is left to cool to room temperature of 22-24℃ to obtain a high-performance copper alloy for electronic materials.

[0027] Furthermore, the concentration of the ethanol solution is 40-50 wt%, and the concentration of the sodium periodate solution is 0.1 M.

[0028] Furthermore, the concentration of the sodium periodate solution is 0.1M.

[0029] Furthermore, the volume ratio of citrate ethanol buffer, tyrosine-triethanolamine premix, and sodium periodate solution is (80-85):1.8:0.1.

[0030] Further, the steps for adding hydrophobic nano-silica in stages are as follows: first, add 1-1.2 parts by mass of hydrophobic nano-silica and sonicate for 5-7 minutes; then add 1.5-1.8 parts by mass of hydrophobic nano-silica and sonicate for 5-10 minutes; finally, add 1.5-2 parts by mass of hydrophobic nano-silica and sonicate for 10-15 minutes to obtain a nano-silica dispersion.

[0031] A high-performance copper alloy for electronic materials is prepared by the above-described method for preparing high-performance copper alloys for electronic materials.

[0032] The present invention has the following advantages:

[0033] 1. This invention prepares copper alloy materials through the Cu-Al-Fe-Si alloy system. This step not only prepares the copper alloy substrate, but also prepares an ideal substrate for subsequent surface functionalization through the synergistic design of material composition and microstructure. Aluminum, as a core additive element, preferentially and selectively dissolves in the etching solution, forming not only micron-sized pores but also nanosheet-like structures through its hydrolysis and redeposition products, thus directly forming the micro-nano-level rough surface required for superhydrophobicity. Iron forms fine Fe-Al intermetallic compounds, constituting microscopic galvanic cells with the aluminum-rich phase, accelerating and deepening the dissolution of the aluminum phase, making the etched structure more complex and providing richer contact with the bio-based hydrophobic coating solution, thereby achieving better coating adhesion. Silicon accumulates on the etched surface, forming a thin layer of hydroxyl-rich silicon oxide. This active layer can form strong interactions such as hydrogen bonds with the polar groups in the bio-based coating, significantly improving coating adhesion. The non-equilibrium microstructure obtained by the melt spin quenching process ensures extremely uniform component distribution, allowing the etching solution to react uniformly on the surface of the prepared copper alloy material during subsequent etching, avoiding uneven etching caused by component segregation, and thus improving the uniformity of coating adhesion. The copper alloy material obtained after etching has both optimized physical roughness and chemical activity, which allows the bio-based coating to adhere firmly to the etched copper alloy material surface, thereby obtaining a high-performance superhydrophobic coating.

[0034] 2. This invention utilizes a compound of L-tyrosine and sodium periodate to prepare an etching solution. The core mechanism lies in the redox-coordination synergistic effect between L-tyrosine and sodium periodate. Sodium periodate, as a strong oxidant, can oxidize the surface of copper alloys, converting metallic copper into soluble oxidized copper ions, thus initiating etching. Simultaneously, it specifically oxidizes the phenolic hydroxyl groups in the L-tyrosine molecule, converting them into highly reactive quinone intermediates. The activated quinone structure can efficiently capture copper ions in the solution, forming a stable copper-organic coordination complex, achieving self-promoting etching and guiding corrosion products to the treatment process. The deposition and assembly of copper alloy materials directly constructs a uniform and stable organic-inorganic hybrid micro / nano-hierarchical rough structure on the surface of the copper alloy. This structure has two major advantages: First, its complex microstructure provides a huge specific surface area and mechanical anchoring sites for subsequent bio-based coatings. Second, the organic ligand layer from tyrosine embedded in the structure is rich in polar functional groups, which can form strong interactions such as hydrogen bonds with the molecules of the bio-based hydrophobic coating liquid. Based on physical interlocking, a stronger interfacial chemical bond is established, thereby significantly improving the adhesion strength and long-term durability of the superhydrophobic coating.

[0035] 3. This invention prepares a bio-based hydrophobic coating liquid using carnauba wax and β-carotene. Through the synergistic effect of the two, a functional hydrophobic coating is constructed on an etched copper alloy substrate. Carnauba wax, as the main film-forming substance, forms a dense crystalline network during curing due to its high melting point and long-chain alkane structure, providing the coating with basic structural strength and hydrophobicity. β-carotene, as a functional additive, disperses its linear long-chain conjugated molecular structure within the molten carnauba wax phase, effectively interfering with the regular arrangement and crystallization process of wax molecules, thereby refining the wax crystal size and improving the coating's properties. The structure is more uniform and dense. The core synergy between the two lies in the fact that β-carotene molecules act as heterogeneous nucleation sites in the wax phase, guiding wax crystals to grow at a smaller size and higher density. This refined composite microstructure significantly improves the mechanical toughness, density and coverage of the coating to the substrate. For copper alloy substrates, the denser and tougher composite wax film of carnauba wax and carotene can form a stronger mechanical interlock and barrier with the micro-nano rough structure generated by etching, greatly enhancing its physical protective performance of isolating water and oxygen and resisting environmental corrosion, thereby achieving excellent hydrophobic function. Attached Figure Description

[0036] Figure 1 This is a flowchart of the preparation method of the high-performance copper alloy for electronic materials according to the present invention. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this invention.

[0038] Example 1

[0039] A method for preparing a high-performance copper alloy for electronic materials, such as Figure 1 As shown, it includes the following steps:

[0040] S1: Preparation and processing of copper alloy materials

[0041] High-purity copper, pure iron sheets, high-purity aluminum ingots, and crystalline silicon were added to a graphite crucible, and the mixture was evacuated to a vacuum of 5 × 10⁻⁶. -3 Pa, purged with argon as a protective atmosphere, heated to 1240℃, held for 10 minutes, and electromagnetically stirred until homogeneous to obtain a molten alloy liquid;

[0042] Molten alloy liquid is poured onto a water-cooled copper roller rotating at 2000 rpm for melt quenching to obtain a copper alloy sheet with a thickness of 1 mm.

[0043] Annealing at 400℃ under argon protection for 30 minutes eliminates internal stress, resulting in a copper alloy sheet to be treated. Then, the surface of the copper alloy sheet to be treated is polished sequentially with 800-grit, 1200-grit, 1600-grit, and 2000-grit sandpaper for 10 minutes each, finally yielding the treated copper alloy material.

[0044] The contents of copper, aluminum, iron and silicon, by mass percentage, are as follows: copper: 94 wt%, aluminum: 5 wt%, iron: 0.5 wt%, and silicon: 0.5 wt%.

[0045] S2: Preparation of etching solution

[0046] L-tyrosine powder was added to triethanolamine at a ratio of 1g:150mL. The mixture was stirred continuously at 100rpm and heated to 40°C for 20 minutes until L-tyrosine was evenly dispersed and a viscous, pale yellow solution was formed. Heating was stopped, and the mixture was stirred and cooled to room temperature of 22°C to obtain a tyrosine-triethanolamine premix.

[0047] Citric acid and a 40wt% ethanol solution were mixed at a ratio of 1g:400mL and stirred until dissolved. The pH of the system was then adjusted to 7.5 to obtain a citric acid-ethanol buffer solution.

[0048] Under magnetic stirring at 300 rpm, citrate ethanol buffer was added to tyrosine-triethanolamine premix, the temperature was controlled at 30℃ and stirring was maintained, and 0.1M sodium periodate solution was added to obtain etching solution, wherein the volume ratio of citrate ethanol buffer, tyrosine-triethanolamine premix and sodium periodate solution was 80:1.8:0.1.

[0049] S3: Preparation of bio-based hydrophobic coating liquid

[0050] Weigh 15 parts by weight of carnauba wax, heat it in a water bath to 82°C, stir it magnetically at 200 rpm for 15 minutes, then add 2 parts by weight of rosin glycerol ester, continue stirring for 5 minutes, then add 3 parts by weight of stearic acid, stir evenly to obtain the wax phase;

[0051] 58 parts by weight of anhydrous ethanol, 10 parts by weight of ethyl acetate and 3 parts by weight of turpentine oil were mixed at 300 rpm for 5 minutes to obtain a functional solvent;

[0052] Weigh 0.5 parts by weight of lecithin and add it to the above functional solvent. Stir for 10 minutes until completely dissolved. Then add hydrophobic nano silica in steps. First, add 1 part by weight of hydrophobic nano silica and sonicate for 5 minutes. Then add 1.5 parts by weight of hydrophobic nano silica and sonicate for 5 minutes. Finally, add 1.5 parts by weight of hydrophobic nano silica and sonicate for 10 minutes to obtain a nano silica dispersion.

[0053] Add 2 parts by mass of β-carotene to the nano silica dispersion, stir at 100 rpm for 5 minutes, heat in a water bath to 65°C, add dropwise to the above wax phase while stirring at 800 rpm, raise the temperature to 84°C, increase the stirring speed to 1200 rpm, stir and emulsify for 15 minutes, cool naturally in a water bath to 40°C, and mature by shaking at 60 rpm for 30 minutes. Filter the product through a 200-mesh nylon screen to obtain the bio-based hydrophobic coating liquid.

[0054] S4: Preparation of high-performance copper alloys for electronic materials

[0055] The copper alloy material was subjected to oxygen plasma cleaning at a power of 50W, a treatment time of 45 seconds, and an oxygen flow rate of 15sccm to obtain activated copper alloy material.

[0056] Pour the prepared etching solution into the polytetrafluoroethylene etching tank, completely immerse the activated copper alloy material in the etching solution, soak for 10 minutes while stirring magnetically at 100 rpm, then remove it and immerse it in a cleaner containing 0.1M sodium thiosulfate solution for 30 seconds, then clean it three times each with deionized water and anhydrous ethanol, and blow it dry with high-purity nitrogen to obtain the etched copper alloy substrate.

[0057] The etched copper alloy substrate was preheated to 70°C. The prepared bio-based hydrophobic coating solution was preheated in a 40°C water bath before use. The etched copper alloy substrate was immersed in the preheated bio-based hydrophobic coating solution at a speed of 3 cm / s for 30 seconds. Then it was pulled up at a speed of 0.5 mm / s. Finally, it was left to stand at 40°C for 15 minutes for pre-curing. The temperature was then raised to 86°C and held for 5 minutes. Finally, it was left to stand and cool to room temperature of 22°C to obtain a high-performance copper alloy for electronic materials.

[0058] Example 2

[0059] A method for preparing a high-performance copper alloy for electronic materials, such as Figure 1 As shown, it includes the following steps:

[0060] S1: Preparation and processing of copper alloy materials

[0061] High-purity copper, pure iron sheets, high-purity aluminum ingots, and crystalline silicon were added to a graphite crucible, and the mixture was evacuated to a vacuum of 5 × 10⁻⁶. -3 Pa, purged with argon as a protective atmosphere, heated to 1250℃, held for 12 minutes, and electromagnetically stirred until homogeneous to obtain a molten alloy liquid;

[0062] Molten alloy liquid is poured onto a water-cooled copper roller rotating at 2050 rpm for melt quenching to obtain a copper alloy sheet with a thickness of 1.5 mm.

[0063] Annealing at 420℃ under argon protection for 32 minutes eliminates internal stress, resulting in a copper alloy sheet to be treated. The surface of the copper alloy sheet to be treated is then polished sequentially with 800-grit, 1200-grit, 1600-grit, and 2000-grit sandpaper for 11 minutes each, finally yielding the treated copper alloy material.

[0064] The contents of copper, aluminum, iron and silicon, by mass percentage, are as follows: copper: 92 wt%, aluminum: 6 wt%, iron: 1 wt%, and silicon: 1 wt%.

[0065] S2: Preparation of etching solution

[0066] L-tyrosine powder was added to triethanolamine at a ratio of 1g:155mL. The mixture was stirred continuously at 150rpm and heated to 42°C for 22 minutes until L-tyrosine was evenly dispersed and a viscous, pale yellow solution was formed. Heating was stopped, and the mixture was stirred and cooled to room temperature of 23°C to obtain a tyrosine-triethanolamine premix.

[0067] Citric acid and a 45wt% ethanol solution were mixed at a ratio of 1g:405mL and stirred until dissolved. The pH of the system was then adjusted to 7.8 to obtain a citric acid-ethanol buffer solution.

[0068] Under magnetic stirring at 350 rpm, citrate ethanol buffer was added to tyrosine-triethanolamine premix, the temperature was controlled at 32℃ and stirring was maintained, and 0.1M sodium periodate solution was added to obtain etching solution, wherein the volume ratio of citrate ethanol buffer, tyrosine-triethanolamine premix and sodium periodate solution was 82:1.8:0.1.

[0069] S3: Preparation of bio-based hydrophobic coating liquid

[0070] Weigh 17 parts by weight of carnauba wax, heat it in a water bath to 84°C, stir it magnetically at 210 rpm for 17 minutes, then add 2.5 parts by weight of rosin glycerol ester, continue stirring for 6 minutes, then add 3.5 parts by weight of stearic acid, stir evenly to obtain the wax phase;

[0071] 59 parts by weight of anhydrous ethanol, 11 parts by weight of ethyl acetate and 4 parts by weight of turpentine were mixed at 350 rpm for 8 minutes to obtain a functional solvent.

[0072] Weigh 0.8 parts by weight of lecithin and add it to the above functional solvent. Stir for 10 minutes until completely dissolved. Then add hydrophobic nano silica in steps. First, add 1.1 parts by weight of hydrophobic nano silica and sonicate for 6 minutes. Then add 1.7 parts by weight of hydrophobic nano silica and sonicate for 8 minutes. Finally, add 1.7 parts by weight of hydrophobic nano silica and sonicate for 12 minutes to obtain a nano silica dispersion.

[0073] 2.2 parts by mass of β-carotene were added to the nano-silica dispersion, stirred at 110 rpm for 8 minutes, heated to 68°C in a water bath, and added dropwise to the above wax phase while stirring at 825 rpm. The temperature was raised to 85°C, the stirring speed was increased to 1250 rpm, and the mixture was stirred and emulsified for 17 minutes. The mixture was then naturally cooled to 42°C in a water bath and matured by shaking at 70 rpm for 32 minutes. The product was filtered through a 200-mesh nylon screen to obtain the bio-based hydrophobic coating liquid.

[0074] S4: Preparation of high-performance copper alloys for electronic materials

[0075] The copper alloy material was subjected to oxygen plasma cleaning at a power of 60W, a treatment time of 50 seconds, and an oxygen flow rate of 17sccm to obtain activated copper alloy material.

[0076] Pour the prepared etching solution into the polytetrafluoroethylene etching tank, completely immerse the activated copper alloy material in the etching solution, soak for 12 minutes while magnetically stirring at 125 rpm, then remove it and immerse it in a cleaner containing 0.1M sodium thiosulfate solution for 30 seconds, then clean it 3 times each with deionized water and anhydrous ethanol, and blow it dry with high-purity nitrogen to obtain the etched copper alloy substrate.

[0077] The etched copper alloy substrate was preheated to 72°C. The prepared bio-based hydrophobic coating solution was preheated in a 42°C water bath before use. The etched copper alloy substrate was immersed in the preheated bio-based hydrophobic coating solution at a speed of 3 cm / s for 35 seconds. Then it was pulled up at a speed of 0.8 mm / s. Finally, it was left to stand at 42°C for 17 minutes for pre-curing. The temperature was then raised to 88°C and held for 6 minutes. Finally, it was left to stand and cool to room temperature of 23°C to obtain a high-performance copper alloy for electronic materials.

[0078] Example 3

[0079] A method for preparing a high-performance copper alloy for electronic materials, such as Figure 1 As shown, it includes the following steps:

[0080] S1: Preparation and processing of copper alloy materials

[0081] High-purity copper, pure iron sheets, high-purity aluminum ingots, and crystalline silicon were added to a graphite crucible, and the mixture was evacuated to a vacuum of 5 × 10⁻⁶. -3 Pa, purged with argon as a protective atmosphere, heated to 1260℃, held for 15 minutes, and electromagnetically stirred until homogeneous to obtain a molten alloy liquid;

[0082] Molten alloy liquid is poured onto a water-cooled copper roller rotating at 2100 rpm for melt quenching to obtain a copper alloy sheet with a thickness of 2 mm.

[0083] Annealing at 440℃ under argon protection for 35 minutes eliminates internal stress, resulting in a copper alloy sheet to be treated. The surface of the copper alloy sheet to be treated is then polished sequentially with 800-grit, 1200-grit, 1600-grit, and 2000-grit sandpaper for 12 minutes each, finally yielding the treated copper alloy material.

[0084] The contents of copper, aluminum, iron and silicon, by mass percentage, are as follows: copper: 93 wt%, aluminum: 5.5 wt%, iron: 0.7 wt%, and silicon: 0.8 wt%.

[0085] S2: Preparation of etching solution

[0086] L-tyrosine powder was added to triethanolamine at a ratio of 1g:160mL. The mixture was stirred continuously at 200rpm and heated to 45°C for 25 minutes until L-tyrosine was evenly dispersed and a viscous, pale yellow solution was formed. Heating was stopped, and the mixture was stirred and cooled to room temperature of 24°C to obtain a tyrosine-triethanolamine premix.

[0087] Citric acid and a 50wt% ethanol solution were mixed at a ratio of 1g:410mL and stirred until dissolved. The pH of the system was then adjusted to 8.0 to obtain a citric acid-ethanol buffer solution.

[0088] Under magnetic stirring at 400 rpm, citrate ethanol buffer was added to tyrosine-triethanolamine premix, the temperature was controlled at 35°C and stirring was maintained, and 0.1 M sodium periodate solution was added to obtain etching solution, wherein the volume ratio of citrate ethanol buffer, tyrosine-triethanolamine premix and sodium periodate solution was 85:1.8:0.1.

[0089] S3: Preparation of bio-based hydrophobic coating liquid

[0090] Weigh 20 parts by weight of carnauba wax, heat it in a water bath to 86°C, stir magnetically at 220 rpm for 20 minutes, then add 3 parts by weight of rosin glycerol ester, continue stirring for 7 minutes, then add 4 parts by weight of stearic acid, stir evenly to obtain the wax phase;

[0091] 60 parts by weight of anhydrous ethanol, 12 parts by weight of ethyl acetate and 5 parts by weight of turpentine oil were mixed at 400 rpm for 10 minutes to obtain a functional solvent.

[0092] Weigh 1 part by mass of lecithin and add it to the above functional solvent. Stir for 10 minutes until completely dissolved. Then add hydrophobic nano silica in steps. First, add 1.2 parts by mass of hydrophobic nano silica and sonicate for 7 minutes. Then add 1.8 parts by mass of hydrophobic nano silica and sonicate for 10 minutes. Finally, add 2 parts by mass of hydrophobic nano silica and sonicate for 15 minutes to obtain a nano silica dispersion.

[0093] Add 2.5 parts by mass of β-carotene to the nano silica dispersion, stir at 120 rpm for 10 minutes, heat in a water bath to 70°C, and add dropwise to the above wax phase while stirring at 850 rpm. Raise the temperature to 86°C, increase the stirring speed to 1300 rpm, stir and emulsify for 20 minutes, cool naturally in a water bath to 45°C, and mature by shaking at 80 rpm for 35 minutes. Filter the product through a 200-mesh nylon screen to obtain a bio-based hydrophobic coating liquid.

[0094] S4: Preparation of high-performance copper alloys for electronic materials

[0095] The copper alloy material was subjected to oxygen plasma cleaning at a power of 80W, a treatment time of 60 seconds, and an oxygen flow rate of 20sccm to obtain activated copper alloy material.

[0096] Pour the prepared etching solution into the polytetrafluoroethylene etching tank, completely immerse the activated copper alloy material in the etching solution, soak for 15 minutes while magnetically stirring at 150 rpm, then remove it and immerse it in a cleaner containing 0.1M sodium thiosulfate solution for 30 seconds, then clean it three times each with deionized water and anhydrous ethanol, and blow it dry with high-purity nitrogen to obtain the etched copper alloy substrate.

[0097] The etched copper alloy substrate was preheated to 75°C. The prepared bio-based hydrophobic coating solution was preheated in a 45°C water bath before use. The etched copper alloy substrate was immersed in the preheated bio-based hydrophobic coating solution at a speed of 3 cm / s for 40 seconds. Then it was pulled up at a speed of 1 mm / s. Finally, it was left to stand at 45°C for 20 minutes for pre-curing. The temperature was then raised to 90°C and held for 8 minutes. Finally, it was left to stand and cool to room temperature of 24°C to obtain a high-performance copper alloy for electronic materials.

[0098] Comparative Example 1:

[0099] Compared with Example 1, the difference of Comparative Example 1 is that the treated copper alloy material prepared in step S1 is replaced with a commercially available copper alloy whose main components are Sn: 0.12wt%, impurities: 0.002-0.01wt%, and balance Cu. The treated copper alloy material is replaced with an equal mass of commercially available copper alloy in step S4, while the other steps remain unchanged. This is referred to as Comparative Example 1.

[0100] Comparative Example 2:

[0101] Compared with Example 1, Comparative Example 2 differs in that step S2 is omitted, and the etching solution in step S4 is replaced by a sodium periodate solution with a concentration of 0.1M. The remaining steps remain unchanged, and this is referred to as Comparative Example 2.

[0102] Comparative Example 3:

[0103] Compared with Example 1, Comparative Example 3 differs in that sodium periodate solution is not added in step S2, the volume ratio of citrate ethanol buffer and tyrosine-triethanolamine premix is ​​80:1.9, and the other steps remain unchanged. It is referred to as Comparative Example 3.

[0104] Comparative Example 4:

[0105] Compared with Example 1, Comparative Example 4 differs in that the etching solution in step S4 is replaced by an FeCl3 solution with a concentration of 1.5 mol / L, while the other steps remain unchanged. This is referred to as Comparative Example 4.

[0106] Comparative Example 5:

[0107] Compared with Example 1, Comparative Example 5 differs in that carnauba wax is not added in step S3, and beeswax or the same mass is used instead of carnauba wax. The remaining steps remain unchanged, and it is referred to as Comparative Example 5.

[0108] Comparative Example 6:

[0109] Compared with Example 1, Comparative Example 6 differs in that β-carotene is not added in step S3, and anthocyanins are used in place of β-carotene by mass, while the other steps remain unchanged. It is referred to as Comparative Example 6.

[0110] The coating adhesion strength of Examples 1-3 and Comparative Examples 1-4 was tested using the cross-cut test in GB / T9286-2021 "Paints and Varnishes - Cross-cut Test". The results are shown in Table 1.

[0111] The UV aging of Examples 1-3 and Comparative Examples 1-4 was carried out for 250h and 500h respectively using the specific implementation method in GB / T23987.3-2025 "Laboratory Light Source Exposure Methods for Paints and Varnishes Part 3: Fluorescent UV Lamp". The adhesion strength of the aged coatings was tested, and the results are shown in Table 2.

[0112] The static water contact angles of Examples 1-3 and Comparative Examples 5-6 were measured according to GB / T30693-2014 "Determination of Water Contact Angle on Plastic Surfaces". The tests were repeated 5 times, and the average value and standard deviation were added. The results are shown in Table 3.

[0113] Table 1

[0114]

[0115] Table 2

[0116]

[0117] Table 3

[0118]

[0119] As can be seen from Tables 1 and 2, the adhesion strength of the commercially available copper alloy in Comparative Example 1 is significantly lower than that in Examples 1-3, and the performance degradation is more pronounced after UV aging. The adhesion strength of Comparative Example 1 after 250h and 500h of aging is 5B and 6B, respectively, while the adhesion strength of Examples 1-3 after 500h of aging is 3B. This indicates that the copper alloy prepared by the present invention through the Cu-Al-Fe-Si alloy system and melt spin quenching has a surface microstructure or chemical properties that are more conducive to coating adhesion, and commercially available ordinary copper alloys cannot achieve the same effect.

[0120] The adhesion strength of Comparative Example 2 (using only sodium periodate solution) and Comparative Example 3 (omitting sodium periodate in the etching solution) was poor, at 2B, and decreased to 3B and 4B after aging for 250h and 500h, respectively. This indicates that sodium periodate is crucial as an oxidant, and the composite system composed of L-tyrosine, triethanolamine, and citrate-ethanol buffer works synergistically with sodium periodate to form suitable roughness or chemically active sites on the copper alloy surface, significantly improving coating adhesion and durability. Single-component etchants cannot achieve the effect of the etching solution of this invention.

[0121] Comparative Example 4, which used FeCl3 solution, showed poor adhesion strength (3B), and the adhesion strength deteriorated significantly after 250h and 500h of aging. This indicates that traditional etchants cannot achieve the effect of the etchant solution of this invention.

[0122] As can be seen from Table 3, the water contact angle of Examples 1-3 is around 158°. The static water contact angles of Comparative Example 5 (using beeswax instead of carnauba wax) and Comparative Example 6 (using anthocyanins instead of β-carotene) are reduced to around 143° and 141° respectively, which are much lower than those of the Examples. This indicates that carnauba wax has better film-forming properties and hydrophobic enhancement effects. β-carotene, as a natural hydrophobic component, has a better synergistic effect with carnauba wax and nano-silica than anthocyanins. The two work together to construct a stable superhydrophobic micro / nano structure.

[0123] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Parts not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A method for preparing a high-performance copper alloy for electronic materials, characterized by comprising the following steps: High-purity copper, pure iron sheets, high-purity aluminum ingots, and crystalline silicon were added to a graphite crucible, and the mixture was evacuated to a vacuum of 5 × 10⁻⁶. -3 Pa, purged with argon as a protective atmosphere, heated to 1240-1260℃, held for 10-15 minutes, and electromagnetically stirred to obtain a molten alloy liquid; Molten alloy liquid is poured onto a water-cooled copper roller with a rotation speed of 2000-2100 rpm for melt quenching to obtain copper alloy sheet with a thickness of 1-2 mm. Anneal at 400-440℃ under argon protection for 30-35 minutes to eliminate internal stress and obtain the copper alloy sheet to be treated. Then, use 800-grit, 1200-grit, 1600-grit and 2000-grit sandpaper to grind the surface of the copper alloy sheet to be treated for 10-12 minutes in sequence to finally obtain the treated copper alloy material. The copper alloy material was subjected to oxygen plasma cleaning at a power of 50-80W, a treatment time of 45-60 seconds, and an oxygen flow rate of 15-20 sccm to obtain activated copper alloy material. The activated copper alloy material is completely immersed in the etching solution for etching to obtain the etched copper alloy substrate. The etched copper alloy substrate is immersed in a preheated bio-based hydrophobic coating liquid and then cured to obtain a high-performance copper alloy for electronic materials. The contents of copper, aluminum, iron and silicon, by mass percentage, are as follows: copper: 92-94 wt%, aluminum: 5-6 wt%, iron: 0.5-1 wt%, silicon: 0.5-1 wt%, and the total amount of each component is 100%. The etching solution is prepared as follows: L-tyrosine powder is added to triethanolamine at a ratio of 1g:(150-160)mL, stirred continuously at 100-200rpm and heated to 40-45℃ for 20-25 minutes until L-tyrosine is evenly dispersed and a viscous light yellow solution is formed. Heating is stopped, and stirring is continued to cool to room temperature of 22-24℃ to obtain tyrosine-triethanolamine premixed solution. Citric acid and ethanol solution were mixed at a ratio of 1 g to (400-410) mL and stirred until dissolved. The pH of the system was then adjusted to 7.5-8.0 to obtain citric acid-ethanol buffer solution. While magnetically stirring at 300-400 rpm, add citrate ethanol buffer to tyrosine-triethanolamine premix, maintain the temperature at 30-35℃, and continue stirring. Then add sodium periodate solution. The volume ratio of citrate ethanol buffer, tyrosine-triethanolamine premix, and sodium periodate solution should be (80-85). A 1.8:0.1 ratio yields the etching solution; The preparation method of bio-based hydrophobic coating liquid is as follows: Weigh 15-20 parts by weight of carnauba wax, heat it in a water bath to 82-86℃, stir magnetically at 200-220 rpm for 15-20 min, then add 2-3 parts by weight of rosin glycerol ester, continue stirring for 5-7 min, then add 3-4 parts by weight of stearic acid, stir evenly to obtain the wax phase; Mix 58-60 parts by weight of anhydrous ethanol, 10-12 parts by weight of ethyl acetate and 3-5 parts by weight of turpentine oil at 300-400 rpm for 5-10 minutes to obtain a functional solvent; Weigh 0.5-1 parts by weight of lecithin and add it to the above functional solvent. Stir for 10 minutes until completely dissolved, and then add hydrophobic nano silica in steps to obtain a nano silica dispersion. Add 2-2.5 parts by weight of β-carotene to the nano-silica dispersion, stir at 100-120 rpm for 5-10 minutes, heat in a water bath to 65-70℃, and add dropwise to the above wax phase while stirring at 800-850 rpm. Raise the temperature to 84-86℃, increase the stirring speed to 1200-1300 rpm, stir and emulsify for 15-20 minutes, cool naturally in a water bath to 40-45℃, and mature by shaking at 60-80 rpm for 30-35 minutes. Filter the product through a 200-mesh nylon screen to obtain the bio-based hydrophobic coating liquid.

2. The method for preparing high-performance copper alloys for electronic materials according to claim 1, characterized in that, The specific steps for etching activated copper alloy materials by immersion in etching solution are as follows: Pour the prepared etching solution into a polytetrafluoroethylene etching tank, completely immerse the activated copper alloy material in the etching solution, soak for 10-15 minutes while magnetically stirring at 100-150 rpm, then remove it and immerse it in a cleaner containing 0.1M sodium thiosulfate solution for 30 seconds. Then clean it three times each with deionized water and anhydrous ethanol, and blow it dry with high-purity nitrogen to obtain the etched copper alloy substrate.

3. The method for preparing high-performance copper alloys for electronic materials according to claim 2, characterized in that, The specific steps for immersing and curing the etched copper alloy substrate in a preheated bio-based hydrophobic coating solution are as follows: The etched copper alloy substrate is preheated to 70-75℃. The prepared bio-based hydrophobic coating solution is preheated in a water bath at 40-45℃ before use. The etched copper alloy substrate is immersed in the preheated bio-based hydrophobic coating solution at a speed of 3cm / s for 30-40s. Then it is pulled up at a speed of 0.5-1mm / s. Finally, it is left to stand at 40-45℃ for 15-20 minutes for pre-curing. Then the temperature is raised to 86-90℃ and held for 5-8 minutes. Finally, it is left to cool to room temperature of 22-24℃ to obtain a high-performance copper alloy for electronic materials.

4. The method for preparing high-performance copper alloys for electronic materials according to claim 1, characterized in that, The concentration of the ethanol solution is 40-50 wt%.

5. The method for preparing high-performance copper alloys for electronic materials according to claim 1, characterized in that, The concentration of the sodium periodate solution is 0.1M.

6. The method for preparing high-performance copper alloys for electronic materials according to claim 1, characterized in that, The steps for adding hydrophobic nano-silica in stages are as follows: First, add 1-1.2 parts by weight of hydrophobic nano-silica and sonicate for 5-7 minutes. Then, add 1.5-1.8 parts by weight of hydrophobic nano-silica and sonicate for 5-10 minutes. Finally, add 1.5-2 parts by weight of hydrophobic nano-silica and sonicate for 10-15 minutes to obtain a nano-silica dispersion.

7. A high-performance copper alloy for use in electronic materials, characterized in that, It is prepared by the method for preparing high-performance copper alloys for electronic materials as described in any one of claims 1-6.

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