Ultrathin porous copper foil

Abstract

The invention discloses an ultrathin porous copper foil, and belongs to the technical field of porous copper foil preparation. The preparation method of the ultra-thin porous copper foil comprises the following steps: step 1, placing a pure titanium plate and an iridium-plated titanium plate in a basic electrolyte, electrifying for electrolysis, washing and drying to obtain a substrate copper foil; step 2, adding a substrate copper foil and the iridium-plated titanium plate into an electrolyte, electrifying for electrolysis, and after electrolysis is finished, washing, blow-drying and stripping to obtain aluminum-containing deposited copper; thirdly, the aluminum-containing deposited copper is placed in a heat treatment furnace to be heated, heat treatment alloy deposition is obtained, then the heat treatment alloy deposition is placed in etching liquid, and porous alloy deposition is obtained; and 4, depositing and adding the porous alloy into a sodium hydroxide solution to obtain the ultra-thin porous copper foil. The ultrathin porous copper foil prepared by the method has excellent porosity.

Description

Technical Field

[0001] The invention belongs to the technical field of ultra-thin porous copper foil preparation, and in particular relates to an ultra-thin porous copper foil. Background Art

[0002] In the field of modern materials science, copper foil, as an important conductive and heat dissipation material, plays a vital role in lithium-ion batteries, electronic packaging, integrated circuits, and microelectronic devices. In particular, with the rapid development of new energy, information technology, and microelectronics technology, the performance requirements for copper foil are getting higher and higher. It is not only required to have excellent electrical and thermal conductivity, but also to have high strength, high heat resistance, good processability, and lightweight. Therefore, ultra-thin porous copper foil came into being, and with its unique structural and performance advantages, it has become one of the hot spots in the field of copper foil material research.

[0003] Patent CN 117021634 A discloses a method for preparing an ultra-thin composite copper foil, comprising the following steps: P1: bonding 10 micron thick lithium battery grade electrolytic copper foil and polymer substrate adhesive or directly hot pressing and bonding to form a thick copper layer composite copper foil coil; P2: mechanical processing; P3: electroplating copper leveling; P4: ultra-thin composite copper foil coil. The preparation method of the invention is simple and has low production cost, but the porosity of the ultra-thin porous copper foil prepared by this method still has room for improvement. Summary of the invention

[0004] The object of the present invention is to provide an ultra-thin porous copper foil, which is used to solve the technical problem of poor porosity of the ultra-thin porous copper foil in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: The present invention provides an ultra-thin porous copper foil, wherein the preparation method comprises the following steps: Step 1: Dissolve copper sulfate and sulfuric acid in deionized water, stir evenly to obtain a basic electrolyte, then place a pure titanium plate and an iridium-plated titanium plate in the basic electrolyte, heat, and electrolyze. After the electrolysis is completed, take out the pure titanium plate, wash it, and blow it dry to obtain a base copper foil; Step 2: adding organic acid, sodium chloride, sodium hydroxide, copper sulfate and aluminum sulfate to deionized water, stirring evenly to obtain an electrolyte, then adding the base copper foil and the iridium-plated titanium plate to the electrolyte, heating, powering on the electrolysis, after the electrolysis is completed, taking out the base copper foil, rinsing, drying, and peeling to obtain aluminum-containing deposited copper; Step 3: placing the aluminum-containing deposited copper in a heat treatment furnace, heating it under nitrogen protection, cooling it after the treatment to obtain a heat-treated alloy deposit, and then placing it in an etching solution, standing it, washing it, and drying it to obtain a porous alloy deposit; Step 4: Add the porous alloy deposit into a sodium hydroxide solution, let it stand, take it out, wash it, put it into a hydrochloric acid solution, treat it, wash it, and blow it dry to obtain an extremely thin porous copper foil.

[0006] Preferably, in step 1, the usage ratio of copper sulfate, sulfuric acid and deionized water is (60-80) g: (70-108) g: (1-1.2) L, the specifications of the pure titanium plate and the iridium-plated titanium plate are both 130 mm × 60 mm × 2 mm, the spacing between the pure titanium plate and the iridium-plated titanium plate is 50-55 mm, the heating temperature is 40-45 ° C, and the current density during the electrolysis process is 8-10 A / cm 2 , the electrolysis time is 6-8min.

[0007] Preferably, in step 2, the method for preparing an organic acid comprises the following steps: Q1: zinc nitrate, 5,5'-(ethane-1,2-diyl)diisophthalic acid and 4,4'-bis(1-imidazolyl)biphenyl are mixed to obtain a mixture, and then N,N-dimethylformamide, distilled water and nitric acid are mixed to obtain a mixed solution; Q2: Slowly add the mixture into the mixed solution, stir to dissolve, then transfer to an oven, dry, and cool to obtain an organic acid.

[0008] Preferably, in Q1, the dosage ratio of zinc nitrate, 5,5'-(ethane-1,2-diyl)diisophthalic acid, 4,4'-bis(1-imidazolyl)biphenyl, N,N-dimethylformamide, distilled water and nitric acid is (0.03-0.045) g: (0.02-0.03) g: (0.01-0.015) g: (5-7.5) mL: (1-1.5) mL: (0.1-0.15) mL, and the concentration of nitric acid is 6 mol / L.

[0009] Preferably, in Q2, the stirring and dissolving time is 1-2 hours, the drying temperature is 95-100°C, the drying time is 30-36 hours, and the mixture is cooled to 25-28°C.

[0010] Preferably, in step 2, the dosage ratio of organic acid, sodium chloride, sodium hydroxide, copper sulfate, aluminum sulfate and deionized water is (80-100) g: (20-25) g: (120-150) g: (8.96-10.12) g: (3.89-4.12) g: (1-1.25) L, the stirring time is 2-3 h, the heating temperature is 40-50 ° C, and the current density during the electrolysis process is 1-1.5 A / cm 2 , time is 20-30min.

[0011] Preferably, in step three, the heating treatment temperature is 800-950° C. and the standing time is 6-8 hours.

[0012] Preferably, in step 4, the mass fraction of the sodium hydroxide solution is 5wt%, the standing time is 10-12h, and the washing is performed with deionized water and anhydrous ethanol. The concentration of the hydrochloric acid solution is 3mol / L, the treatment time is 60-75s, and the washing is performed with anhydrous ethanol and deionized water.

[0013] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: The ultra-thin porous copper foil prepared by the present invention has a more uniform current distribution due to its porous structure, and the extremely thin thickness reduces the resistance and improves the conductive efficiency; the presence of the porous structure also increases the contact area with the environment, promotes the rapid dissipation of heat, and makes the gas convection and radiation heat dissipation mechanism in the pores more effective in a high temperature environment. DETAILED DESCRIPTION

[0014] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] Example 1: This example discloses a method for preparing an organic acid, comprising the following steps: Q1: 0.037 g of zinc nitrate, 0.025 g of 5,5'-(ethane-1,2-diyl)diisophthalic acid and 0.012 g of 4,4'-bis(1-imidazolyl)biphenyl were mixed to obtain a mixture, and then 6.25 mL of N,N-dimethylformamide, 1.25 mL of distilled water and 0.12 mL of 6 mol / L nitric acid were mixed to obtain a mixed solution; Q2: Slowly add the mixture into the mixed solution, stir and dissolve for 2 hours, then transfer to an oven, dry at 100°C for 36 hours, and cool to 25°C to obtain an organic acid.

[0016] This embodiment discloses an ultra-thin porous copper foil having a dispersion-strengthened copper / pure copper composite structure, and the preparation method comprises the following steps: Step 1: Dissolve 70g of copper sulfate and 69g of sulfuric acid in 1.1L of deionized water, stir evenly to obtain a basic electrolyte, and then place a pure titanium plate and an iridium-plated titanium plate with a specification of 130mm×60mm×2mm in the basic electrolyte with a spacing of 50mm. Heat at 40℃ and electrolyze for 6min with a current density of 8A / cm 2After the electrolysis is completed, the pure titanium plate is taken out, washed, and dried to obtain a base copper foil; Step 2: Add 90g of organic acid, 22.5g of sodium chloride, 135g of sodium hydroxide, 9.53g of copper sulfate and 4.01g of aluminum sulfate to 1.12L of deionized water, stir for 3h to obtain an electrolyte, then add the base copper foil and the iridium-plated titanium plate to the electrolyte, heat at 50°C, and electrolyze with a current density of 1A / cm 2 After the electrolysis is completed for 30 minutes, the base copper foil is taken out, rinsed, blown dry, and peeled off to obtain aluminum-containing deposited copper; Step 3: placing the aluminum-containing deposited copper in a heat treatment furnace, heating it at 850°C under nitrogen protection, cooling it after the treatment to obtain a heat-treated alloy deposit, and then placing it in an etching solution, standing it for 8 hours, washing it, and drying it to obtain a porous alloy deposit; Step 4: Add the porous alloy deposit to a 5wt% sodium hydroxide solution, let it stand for 12h, take it out, wash it with deionized water and anhydrous ethanol, put it into a 3mol / L hydrochloric acid solution, treat it for 75s, wash it with anhydrous ethanol and deionized water, blow it dry, and obtain an extremely thin porous copper foil.

[0017] Example 2: This example discloses a method for preparing an organic acid, comprising the following steps: Q1: 0.03 g of zinc nitrate, 0.03 g of 5,5'-(ethane-1,2-diyl)diisophthalic acid and 0.01 g of 4,4'-bis(1-imidazolyl)biphenyl were mixed to obtain a mixture, and then 7.5 mL of N,N-dimethylformamide, 1 mL of distilled water and 0.15 mL of 6 mol / L nitric acid were mixed to obtain a mixed solution; Q2: Slowly add the mixture into the mixed solution, stir and dissolve for 2 hours, then transfer to an oven, dry at 100°C for 36 hours, and cool to 25°C to obtain an organic acid.

[0018] This embodiment discloses an ultra-thin porous copper foil having a dispersion-strengthened copper / pure copper composite structure, and the preparation method comprises the following steps: Step 1: Dissolve 60g of copper sulfate and 108g of sulfuric acid in 1.2L of deionized water, stir evenly to obtain a basic electrolyte, and then place a pure titanium plate and an iridium-plated titanium plate with a specification of 130mm×60mm×2mm in the basic electrolyte with a spacing of 50mm, heat at 40℃, and electrolyze for 6min with a current density of 8A / cm 2 After the electrolysis is completed, the pure titanium plate is taken out, washed, and dried to obtain a base copper foil; Step 2: Add 80g of organic acid, 25g of sodium chloride, 120g of sodium hydroxide, 8.96g of copper sulfate and 4.12g of aluminum sulfate to 1.25L of deionized water, stir for 3h to obtain an electrolyte, then add the base copper foil and the iridium-plated titanium plate to the electrolyte, heat at 50°C, and electrolyze with a current density of 1A / cm 2 After the electrolysis is completed for 30 minutes, the base copper foil is taken out, rinsed, blown dry, and peeled off to obtain aluminum-containing deposited copper; Step 3: placing the aluminum-containing deposited copper in a heat treatment furnace, heating it at 850°C under nitrogen protection, cooling it after the treatment to obtain a heat-treated alloy deposit, and then placing it in an etching solution, standing it for 8 hours, washing it, and drying it to obtain a porous alloy deposit; Step 4: Add the porous alloy deposit to a 5wt% sodium hydroxide solution, let it stand for 12h, take it out, wash it with deionized water and anhydrous ethanol, put it into a 3mol / L hydrochloric acid solution, treat it for 75s, wash it with anhydrous ethanol and deionized water, blow it dry, and obtain an extremely thin porous copper foil.

[0019] Example 3: This example discloses a method for preparing an organic acid, comprising the following steps: Q1: 0.045 g of zinc nitrate, 0.02 g of 5,5'-(ethane-1,2-diyl)diisophthalic acid and 0.015 g of 4,4'-bis(1-imidazolyl)biphenyl were mixed to obtain a mixture, and then 5 mL of N,N-dimethylformamide, 1.5 mL of distilled water and 0.1 mL of 6 mol / L nitric acid were mixed to obtain a mixed solution; Q2: Slowly add the mixture into the mixed solution, stir and dissolve for 2 hours, then transfer to an oven, dry at 100°C for 36 hours, and cool to 25°C to obtain an organic acid.

[0020] This embodiment discloses an ultra-thin porous copper foil having a dispersion-strengthened copper / pure copper composite structure, and the preparation method comprises the following steps: Step 1: Dissolve 80g of copper sulfate and 70g of sulfuric acid in 1L of deionized water, stir evenly to obtain a basic electrolyte, and then place a pure titanium plate and an iridium-plated titanium plate with a specification of 130mm×60mm×2mm in the basic electrolyte with a spacing of 50mm. Heat at 40℃ and electrolyze for 6min with a current density of 8A / cm 2 After the electrolysis is completed, the pure titanium plate is taken out, washed, and dried to obtain a base copper foil; Step 2: Add 100g of organic acid, 20g of sodium chloride, 150g of sodium hydroxide, 10.12g of copper sulfate and 3.89g of aluminum sulfate to 1L of deionized water, stir for 3h to obtain an electrolyte, then add the base copper foil and the iridium-plated titanium plate to the electrolyte, heat at 50°C, and electrolyze with a current density of 1A / cm 2 After the electrolysis is completed for 30 minutes, the base copper foil is taken out, rinsed, blown dry, and peeled off to obtain aluminum-containing deposited copper; Step 3: placing the aluminum-containing deposited copper in a heat treatment furnace, heating it at 850°C under nitrogen protection, cooling it after the treatment to obtain a heat-treated alloy deposit, and then placing it in an etching solution, standing it for 8 hours, washing it, and drying it to obtain a porous alloy deposit; Step 4: Add the porous alloy deposit to a 5wt% sodium hydroxide solution, let it stand for 12h, take it out, wash it with deionized water and anhydrous ethanol, put it into a 3mol / L hydrochloric acid solution, treat it for 75s, wash it with anhydrous ethanol and deionized water, blow it dry, and obtain an extremely thin porous copper foil.

[0021] Comparative Example 1: Compared with Example 1, in the process of preparing the organic acid in Comparative Example 1, no 4,4'-bis(1-imidazolyl)biphenyl was added, and other conditions remained unchanged.

[0022] Comparative Example 2: Compared with Example 1, in Comparative Example 2, during the process of preparing the ultra-thin porous copper foil, no organic acid is added, and other conditions remain unchanged.

[0023] Experimental example: The porosity of the sample was tested using the gas adsorption method. The test results are shown in the following table: Table 1 project Porosity / % Example 1 65.73 Example 2 65.34 Example 3 65.41 Comparative Example 1 60.12 Comparative Example 2 58.94 From the test results in Table 1, it can be seen that the ultra-thin porous copper foil prepared in Examples 1-3 of the present invention has excellent porosity. From the comparison between Comparative Example 1 and Examples 1-3, it can be seen that the addition of 4,4'-bis(1-imidazolyl)biphenyl can effectively improve the porosity of the ultra-thin porous copper foil; from the comparison between Comparative Example 2 and Examples 1-3, it can be seen that the addition of organic acid can effectively improve the porosity of the ultra-thin porous copper foil.

[0024] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0025] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An ultra-thin porous copper foil, characterized in that: The method for preparing an ultra-thin porous copper foil comprises the following steps: Step 1: Dissolve copper sulfate and sulfuric acid in deionized water, stir evenly to obtain a basic electrolyte, then place a pure titanium plate and an iridium-plated titanium plate in the basic electrolyte, heat, and electrolyze. After the electrolysis is completed, take out the pure titanium plate, wash it, and blow it dry to obtain a base copper foil; Step 2: adding organic acid, sodium chloride, sodium hydroxide, copper sulfate and aluminum sulfate to deionized water, stirring evenly to obtain an electrolyte, then adding the base copper foil and the iridium-plated titanium plate to the electrolyte, heating, powering on the electrolysis, after the electrolysis is completed, taking out the base copper foil, rinsing, drying, and peeling to obtain aluminum-containing deposited copper; Step 3: placing the aluminum-containing deposited copper in a heat treatment furnace, heating it under nitrogen protection, cooling it after the treatment to obtain a heat-treated alloy deposit, and then placing it in an etching solution, standing it, washing it, and drying it to obtain a porous alloy deposit; Step 4: Add the porous alloy deposit into a sodium hydroxide solution, let it stand, take it out, wash it, put it into a hydrochloric acid solution, treat it, wash it, and blow it dry to obtain an extremely thin porous copper foil.

2. The ultra-thin porous copper foil according to claim 1, characterized in that In the step 1, the usage ratio of copper sulfate, sulfuric acid and deionized water is (60-80) g: (70-108) g: (1-1.2) L, the specifications of the pure titanium plate and the iridium-plated titanium plate are both 130 mm×60 mm×2 mm, the spacing between the pure titanium plate and the iridium-plated titanium plate is 50-55 mm, the heating temperature is 40-45° C., and the current density during the electrolysis process is 8-10 A / cm 2 , the electrolysis time is 6-8min.

3. The ultra-thin porous copper foil according to claim 1, characterized in that In the step 2, the method for preparing the organic acid comprises the following steps: Q1: zinc nitrate, 5,5'-(ethane-1,2-diyl)diisophthalic acid and 4,4'-bis(1-imidazolyl)biphenyl are mixed to obtain a mixture, and then N,N-dimethylformamide, distilled water and nitric acid are mixed to obtain a mixed solution; Q2: Slowly add the mixture into the mixed solution, stir to dissolve, then transfer to an oven, dry, and cool to obtain an organic acid.

4. The ultra-thin porous copper foil according to claim 3, characterized in that: In Q1, the dosage ratio of zinc nitrate, 5,5'-(ethane-1,2-diyl)diisophthalic acid, 4,4'-bis(1-imidazolyl)biphenyl, N,N-dimethylformamide, distilled water and nitric acid is (0.03-0.045) g: (0.02-0.03) g: (0.01-0.015) g: (5-7.5) mL: (1-1.5) mL: (0.1-0.15) mL, and the concentration of nitric acid is 6 mol / L.

5. The ultra-thin porous copper foil according to claim 3, characterized in that: In Q2, the stirring and dissolving time is 1-2 hours, the drying temperature is 95-100°C, the drying time is 30-36 hours, and the mixture is cooled to 25-28°C.

6. The ultra-thin porous copper foil according to claim 1, characterized in that: In the step 2, the dosage ratio of organic acid, sodium chloride, sodium hydroxide, copper sulfate, aluminum sulfate and deionized water is (80-100) g: (20-25) g: (120-150) g: (8.96-10.12) g: (3.89-4.12) g: (1-1.25) L, the stirring time is 2-3 h, the heating temperature is 40-50 ° C, and the current density during the electrolysis process is 1-1.5 A / cm 2 , time is 20-30min.

7. The ultra-thin porous copper foil according to claim 1, characterized in that: In the step 3, the heating treatment temperature is 800-950° C. and the standing time is 6-8 hours.

8. The ultra-thin porous copper foil according to claim 1, characterized in that In the step 4, the mass fraction of the sodium hydroxide solution is 5wt%, the standing time is 10-12h, and the washing is performed with deionized water and anhydrous ethanol. The concentration of the hydrochloric acid solution is 3mol / L, the treatment time is 60-75s, and the washing is performed with anhydrous ethanol and deionized water.