Preparation process of ultrathin carrier copper foil

Abstract

The invention relates to the technical field of copper foil manufacturing, in particular to a preparation process of an ultrathin carrier copper foil. The prepared appearance improving agent can form a compact adsorption layer on the surface of a carrier copper foil, uneven deposition of metal ions is effectively inhibited, and therefore the roughness degree of the surface of the carrier copper foil is remarkably reduced, and the smoothness of the surface of the carrier copper foil is improved; furthermore, the appearance improving agent and the brightening agent are mutually cooperated and matched to further enhance the regulation and control capability on the surface microstructure of the ultrathin carrier copper foil, so that the integrity and uniformity of the surface of the ultrathin carrier copper foil are effectively improved, and the quality of the ultrathin carrier copper foil is ensured; besides, an organic protective agent is prepared into organic protective liquid, the organic protective liquid is sprayed on the surface of the ultra-thin carrier copper foil, under the mutual cooperation and cooperation effects of the organic protective liquid, the alloy blocking layer and the anti-oxidation electroplating liquid, the oxidation resistance of the ultra-thin carrier copper foil is remarkably improved, the service life of the ultra-thin carrier copper foil is prolonged to a certain extent, and meanwhile the service life of the ultra-thin carrier copper foil is prolonged. And the quality is also ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of copper foil manufacturing, and specifically to a preparation process for an ultra-thin carrier copper foil. Background Art

[0002] With the continuous development of electronic devices towards miniaturization, light weight, and high performance, the demand for ultra-thin copper foils is increasing day by day. As a key electronic material, ultra-thin carrier copper foils have a wide range of applications in fields such as printed circuit boards (PCBs), flexible printed circuit boards (FPCs), and lithium-ion batteries.

[0003] In the patent document with the application number "CN201611022020.4", a preparation method for an ultra-thin carrier copper foil is disclosed. Although the peeling layer prepared in this patent document has the advantages of being extremely thin and uniform, it can make the carrier foil easy to peel off completely and stably. However, it is difficult to precisely control the roughness and smoothness of the copper foil, resulting in unstable quality of the copper foil product. On the other hand, its antioxidant effect is not good, which makes the copper foil easy to be oxidized during storage and use, thus affecting its conductivity and mechanical properties, and reducing the service life and reliability of electronic devices. Therefore, the present invention provides a preparation process for an ultra-thin carrier copper foil to solve the above-mentioned technical problems! Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation process for an ultra-thin carrier copper foil. The ultra-thin carrier copper foil prepared by the present invention not only has the advantages of low roughness and good smoothness, but also has excellent antioxidant properties, which extends its service life to a certain extent while ensuring its quality.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A preparation process for an ultra-thin carrier copper foil, comprising the following steps:

[0007] Step 1: At room temperature, pickle the refined and polished carrier foil with sulfuric acid at a concentration of 70 - 100 g / L. After pickling, wash the carrier foil with deionized water, and then obtain a pretreated carrier foil after vacuum drying treatment;

[0008] Step 2: Use a pulse electroplating alloy electroplating solution on the smooth surface of the pretreated carrier foil, so as to deposit an alloy barrier layer on the surface of the pretreated carrier foil; then electroplate an ultra-thin layer with a copper sulfate electroplating solution to obtain an ultra-thin copper foil layer with a thickness of 2.9 - 3.1 μm; store the obtained rough product of the ultra-thin carrier copper foil for future use;

[0009] Step 3: Coarsely cure the rough product of the ultra-thin carrier copper foil, and then perform anti-oxidation treatment on it with an anti-oxidation plating solution; wherein, the anti-oxidation plating solution contains 15 - 25 g / L of zinc sulfate and 20 - 40 g / L of boric acid; and the temperature of the anti-oxidation electroplating solution is 40 - 50 °C, and the current density during electroplating is set to 2 - 5 A / dm 2 , and the electro-deposition time is 40 - 60 s;

[0010] Step 4: Dissolve the organic protective agent in methanol to prepare an organic protective solution with a concentration of 0.6 - 2 wt%, then evenly spray it on the surface of the ultra-thin carrier copper foil after anti-oxidation treatment, and then obtain the finished product of the ultra-thin carrier copper foil after vacuum drying treatment.

[0011] Furthermore, the carrier foil in Step 1 is a low-roughness copper foil with refined polishing treatment, and its roughness is 0.5 ≤ Rz ≤ 0.8 μm.

[0012] Furthermore, the composition of the alloy electroplating solution includes: 3 - 6 g / L of molybdenum sulfate, 5 - 8 g / L of nickel sulfate, 40 - 60 g / L of cobalt sulfate, 8 - 15 g / L of boric acid, and 3 - 5 g / L of benzotriazole.

[0013] Furthermore, the temperature of the alloy electroplating solution in Step 2 is 45 - 55 °C, and the pH is 3.8 - 4.2.

[0014] Furthermore, the temperature when depositing the alloy barrier layer is 40 - 45 °C; the current density is 25 - 30 A / dm 2 ; the pulse width is 10 - 20 s; the pulse interval is 10 - 20 s; the total application time of the pulse current is 50 - 80 s.

[0015] Furthermore, the composition of the copper sulfate plating solution includes: 60 - 90 g / L of copper sulfate, 100 - 130 g / L of sulfuric acid, 6 - 20 mg / L of hydroxyethyl cellulose, 10 - 40 mg / L of chloride ions, 5 - 8 g / L of polyethylene glycol, 8 - 15 g / L of brightener, 3 - 6 g / L of appearance improver; and the temperature of the copper sulfate plating solution is 40 - 50 °C.

[0016] Furthermore, the brightener is selected from any one of sodium N,N-dimethyldithiocarbamate, sodium polydithiopropanesulfonate, and sodium 3-mercaptopropanesulfonate.

[0017] Furthermore, the preparation method of the appearance improver is as follows: 1,2-diazole is added to toluene at a dosage ratio of 0.2 to 0.5 g / mL, and then dimethyl azobisisobutyrate is added thereto at a mass ratio of 1.5 to 2.5% of 1,2-diazole. After mixing and stirring evenly, the temperature of the resulting mixture is raised to 65 to 80° C. under the protection of nitrogen, and the mixture is stirred and reacted for 5 to 8 hours; after the reaction is completed, the product components are subjected to reduced pressure distillation to remove the toluene therein, and the remaining components are the appearance improver.

[0018] Furthermore, the preparation method of the organic protective agent comprises the following steps:

[0019] Step 1: Add 2,6-di-tert-butyl-p-cresol and γ-chloropropyltrimethoxysilane into a reaction device at a molar ratio of 1:1 to 1.5, stir evenly, add 0.8 to 1.5% by weight of tetrabutylammonium bromide to the resulting mixture, and keep the mixture at 80 to 95°C for 5 to 8 hours;

[0020] Step 2: After the reaction is completed, add 2 to 5 times the mass of γ-aminopropyltriethoxysilane and 0.6 to 0.8 times the mass of deionized water to the resulting component, mix well, and adjust the pH to 4.3 to 4.8 with acetic acid. Then, raise the temperature to 60 to 70°C and stir at this temperature for 2 to 5 hours.

[0021] The third step is to remove low-boiling substances in the reaction product by vacuum distillation after the reaction is completed, dilute it with anhydrous ethanol and then dehydrate it with molecular sieves to obtain an organic protective agent.

[0022] Furthermore, the temperature of the reduced pressure distillation is 80-100° C., the vacuum degree is 0.08-0.1 MPa, and the molecular sieve dehydration time is 25-30 hours.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention comprises adding diazolidine to toluene, adding dimethyl azobisisobutyrate thereto, stirring the mixture uniformly, and then carrying out a heat-insulating stirring reaction under the protection of nitrogen. The resulting product components are subjected to reduced pressure distillation to obtain a surface improver. The resulting surface improver can form a dense adsorption layer on the surface of the carrier copper foil, effectively inhibiting the uneven deposition of metal ions, thereby significantly reducing the surface roughness and improving the surface smoothness. Furthermore, the surface improver and the brightener work together to further enhance the ability to control the surface microstructure of the ultra-thin carrier copper foil, thereby effectively improving the integrity and uniformity of the ultra-thin carrier copper foil surface and ensuring its quality.

[0025] 2. The present invention first uses 2,6-di-tert-butyl-p-cresol and γ-chloropropyltrimethoxysilane as raw materials, which undergo a chemical reaction under the action of tetrabutylammonium bromide. The resulting product components are then uniformly mixed with γ-aminopropyltriethoxysilane. The pH is adjusted to allow the chemical reaction to occur, ultimately successfully bonding the two through chemical bonds. The prepared organic protective agent not only possesses the characteristics of γ-aminopropyltriethoxysilane but also has excellent antioxidant properties. The prepared organic protective agent is formulated into an organic protective liquid and sprayed onto the surface of an ultra-thin carrier copper foil. The synergistic and coordinated effects of the organic protective liquid, the alloy barrier layer, and the anti-oxidation electroplating solution significantly improve the antioxidant properties of the ultra-thin carrier copper foil, extending its service life to a certain extent while also ensuring its quality.

[0026] In summary, the ultra-thin carrier copper foil prepared by the present invention not only has the advantages of low roughness and good smoothness, but also has excellent anti-oxidation performance, which extends its service life to a certain extent while ensuring its quality. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making any creative efforts shall fall within the scope of protection of the present invention.

[0028] Example 1

[0029] A process for preparing an ultrathin carrier copper foil comprises the following steps:

[0030] Step 1: Pickling the refined and polished carrier foil with 70 g / L sulfuric acid at room temperature, washing the carrier foil with deionized water, and then vacuum drying the carrier foil to obtain a pretreated carrier foil; wherein the carrier foil is a refined and polished low-roughness copper foil with a roughness of 0.5 μm;

[0031] Step 2: Pulse electroplating an alloy plating solution on the smooth surface of the pretreated carrier foil to deposit an alloy barrier layer on the surface of the pretreated carrier foil; then electroplating an ultra-thin layer using a copper sulfate plating solution to obtain an ultra-thin copper foil layer of 2.9 μm; the obtained ultra-thin carrier copper foil crude product is stored for future use;

[0032] The alloy electroplating solution comprises: 3 g / L molybdenum sulfate, 5 g / L nickel sulfate, 40 g / L cobalt sulfate, 8 g / L boric acid, and 3 g / L benzotriazole; the temperature of the alloy electroplating solution is 45° C., and the pH is 3.8;

[0033] The temperature during the deposition to form the alloy barrier layer is 40°C; the current density is 25 A / dm 2 ; the pulse width is 10 s; the pulse interval is 10 s; the total application time of the pulsed current is 50 s;

[0034] The composition of the copper sulfate plating solution includes: 60 g / L of copper sulfate, 100 g / L of sulfuric acid, 6 mg / L of hydroxyethyl cellulose, 10 mg / L of chloride ions, 5 g / L of polyethylene glycol, 8 g / L of sodium dimethyldithiocarbamate, 3 g / L of appearance improver; and the temperature of the copper sulfate plating solution is 40°C;

[0035] Step 3: Coarsely cure the ultra-thin carrier copper foil rough product, and then perform anti-oxidation treatment on it with an anti-oxidation plating solution; among them, the anti-oxidation plating solution contains 15 g / L of zinc sulfate and 20 g / L of boric acid; and the temperature of the anti-oxidation electroplating solution is 40°C, and the current density during electroplating is set to 2 A / dm 2 , and the electro-deposition time is 40 s;

[0036] Step 4: Dissolve the organic protective agent in methanol to prepare an organic protective solution with a concentration of 0.6 wt%, then evenly spray it on the surface of the ultra-thin carrier copper foil after anti-oxidation treatment, and then obtain the finished ultra-thin carrier copper foil after vacuum drying treatment.

[0037] The preparation method of the appearance improver is: put m-diazole into toluene according to a dosage ratio of 0.2 g / mL, then add dimethyl azobisisobutyrate with a mass of 1.5% of m-diazole to it, mix and stir evenly, and then raise the temperature of the obtained mixed solution to 65°C under the protection of nitrogen, and keep stirring and reacting for 8 h; after the reaction is completed, perform vacuum distillation on the components of the product to remove the toluene in it, and the remaining components are the appearance improver.

[0038] The preparation method of the organic protective agent includes the following steps:

[0039] The first step: Put 2,6-di-tert-butyl-p-cresol and γ-chloropropyltrimethoxysilane into the reaction equipment according to a molar ratio of 1:1, stir evenly, then add tetrabutylammonium bromide with a mass of 0.8% of it to the obtained mixed material, and keep the temperature at 80°C and react for 8 h;

[0040] The second step: After the reaction is completed, add γ-aminopropyltriethoxysilane with a mass twice that of it and 0.6 times of deionized water to the components of the obtained product, mix evenly, adjust the pH to 4.3 with acetic acid, then raise the temperature to 60°C, and keep stirring and reacting at this temperature for 5 h;

[0041] Step 3: After the reaction is completed, remove the low-boiling substances in the reaction product by vacuum distillation, dilute with absolute ethanol, and then dehydrate with molecular sieves. The final product obtained is the organic protective agent. Among them, the temperature of vacuum distillation is 80°C, the vacuum degree is 0.08 MPa, and the dehydration time of molecular sieves is 25 h.

[0042] Example 2

[0043] A preparation process of an ultra-thin carrier copper foil includes the following steps:

[0044] Step 1: At room temperature, pickle the carrier foil after refining and polishing with 80 g / L sulfuric acid. After pickling, wash the carrier foil with deionized water, and then after vacuum drying treatment, obtain the pretreated carrier foil. Among them, the carrier foil is a low-roughness copper foil after refining and polishing, and its roughness is 0.5 μm.

[0045] Step 2: Use a pulse electroplating alloy plating solution on the smooth surface of the pretreated carrier foil, so as to deposit and form an alloy barrier layer on the surface of the pretreated carrier foil; then electroplate an ultra-thin layer with a copper sulfate plating solution to obtain an ultra-thin copper foil layer of 3 μm; save and reserve the obtained ultra-thin carrier copper foil rough product.

[0046] Among them, the composition of the alloy plating solution includes: 4 g / L molybdenum sulfate, 6 g / L nickel sulfate, 50 g / L cobalt sulfate, 10 g / L boric acid, and 4 g / L benzotriazole; the temperature of the alloy plating solution is 50°C, and the pH is 4.

[0047] The temperature when depositing and forming the alloy barrier layer is 45°C; the current density is 25 A / dm 2 ; the pulse width is 15 s; the pulse interval is 15 s; the total application time of the pulse current is 60 s.

[0048] The composition of the copper sulfate plating solution includes: 70 g / L copper sulfate, 120 g / L sulfuric acid, 10 mg / L hydroxyethyl cellulose, 20 mg / L chloride ions, 6 g / L polyethylene glycol, 12 g / L sodium poly(dithiopropanesulfonate), 5 g / L apparent improver; and the temperature of the copper sulfate plating solution is 45°C.

[0049] Step 3: Perform rough curing treatment on the ultra-thin carrier copper foil rough product, and then perform anti-oxidation treatment on it with an anti-oxidation plating solution. Among them, the anti-oxidation plating solution contains 20 g / L zinc sulfate and 30 g / L boric acid; and the temperature of the anti-oxidation electroplating solution is 45°C, and the current density during electroplating is set to 3 A / dm 2 , and the electrodeposition time is 50 s.

[0050] Step 4: Dissolve the organic protective agent in methanol to prepare an organic protective liquid with a concentration of 1.5 wt%. Then evenly spray it on the surface of the ultrathin carrier copper foil after anti-oxidation treatment, and then obtain the finished ultrathin carrier copper foil after vacuum drying treatment.

[0051] The preparation method of the appearance improver is as follows: Put m - pyrazole into toluene according to the dosage ratio of 0.3 g / mL, and then add dimethyl 2,2'-azobis(2 - methylpropionate) with a mass of 2% of m - pyrazole into it. After mixing and stirring evenly, raise the temperature of the obtained mixed solution to 70 °C under the protection of nitrogen, and keep stirring and reacting for 6 h; After the reaction is completed, carry out vacuum distillation on the components of the product to remove the toluene in it, and the remaining components are the appearance improver.

[0052] The preparation method of the organic protective agent includes the following steps:

[0053] Step 1: Put 2,6 - di - tert - butyl - p - cresol and γ - chloropropyltrimethoxysilane into the reaction equipment according to a molar ratio of 1:1.2. After stirring evenly, add tetrabutylammonium bromide with a mass of 1% of the obtained mixed material into it, and keep the reaction at 85 °C for 6 h;

[0054] Step 2: After the reaction is completed, add γ - aminopropyltriethoxysilane with a mass 3 times that of it and 0.7 times of deionized water to the components of the obtained product. After mixing evenly, adjust the pH to 4.5 with acetic acid, then raise the temperature to 65 °C, and keep stirring and reacting at this temperature for 4 h;

[0055] Step 3: After the reaction is completed, remove the low - boiling substances in the reaction product by vacuum distillation, dilute it with absolute ethanol and then dehydrate it with molecular sieve. The finally obtained product is the organic protective agent; among them, the temperature of vacuum distillation is 90 °C, the vacuum degree is 0.09 MPa, and the molecular sieve dehydration time is 30 h.

[0056] Example 3

[0057] A preparation process of an ultrathin carrier copper foil includes the following steps:

[0058] Step 1: Under normal temperature conditions, pickle the refined and polished carrier foil with sulfuric acid at 100 g / L. After pickling, wash the carrier foil with deionized water, and then obtain the pretreated carrier foil after vacuum drying treatment; among them, the carrier foil is a refined and polished low - roughness copper foil, and its roughness is 0.5 μm;

[0059] Step 2: Use a pulse electroplating alloy electroplating solution on the smooth surface of the pretreated carrier foil, so as to deposit an alloy barrier layer on the surface of the pretreated carrier foil; then electroplate an ultrathin layer with copper sulfate electroplating solution to obtain an ultrathin copper foil layer of 3.1 μm; The obtained rough product of the ultrathin carrier copper foil is stored and reserved for use;

[0060] Among them, the composition of the alloy electroplating solution includes: 6 g / L of molybdenum sulfate, 8 g / L of nickel sulfate, 60 g / L of cobalt sulfate, 15 g / L of boric acid, and 5 g / L of benzotriazole; the temperature of the alloy electroplating solution is 55 °C, and the pH is 4.2;

[0061] The temperature during the deposition of the alloy barrier layer is 45 °C; the current density is 30 A / dm 2 ; the pulse width is 20 s; the pulse interval is 20 s; the total application time of the pulsed current is 80 s;

[0062] The composition of the copper sulfate electroplating solution includes: 90 g / L of copper sulfate, 130 g / L of sulfuric acid, 20 mg / L of hydroxyethyl cellulose, 40 mg / L of chloride ions, 8 g / L of polyethylene glycol, 15 g / L of sodium 3-mercaptopropanesulfonate, and 6 g / L of the appearance improver; and the temperature of the copper sulfate electroplating solution is 50 °C;

[0063] Step 3, perform rough curing treatment on the rough product of the ultra-thin carrier copper foil, and then perform anti-oxidation treatment on it with an anti-oxidation electroplating solution; among them, the anti-oxidation electroplating solution contains 25 g / L of zinc sulfate and 40 g / L of boric acid; and the temperature of the anti-oxidation electroplating solution is 50 °C, and the current density during electroplating is set to 5 A / dm 2 , and the electro-deposition time is 60 s;

[0064] Step 4, dissolve the organic protective agent in methanol to make an organic protective solution with a concentration of 2 wt%, then evenly spray it on the surface of the ultra-thin carrier copper foil after anti-oxidation treatment, and then obtain the finished ultra-thin carrier copper foil after vacuum drying treatment.

[0065] The preparation method of the appearance improver is: put m-diazine into toluene according to a dosage ratio of 0.5 g / mL, then add dimethyl 2,2'-azobis(2-methylpropionate) with a mass of 2.5% of m-diazine to it, mix and stir evenly, and then raise the temperature of the obtained mixture to 80 °C under the protection of nitrogen, and keep stirring and reacting for 5 h; after the reaction is completed, perform vacuum distillation on the components of the product to remove the toluene therein, and the remaining components are the appearance improver.

[0066] The preparation method of the organic protective agent includes the following steps:

[0067] The first step, put 2,6-di-tert-butyl-p-cresol and γ-chloropropyltrimethoxysilane into the reaction equipment according to a molar ratio of 1:1.5, stir evenly, then add tetrabutylammonium bromide with a mass of 1.5% of it to the obtained mixed material, and keep the temperature at 95 °C for 5 h;

[0068] Step 2: After the reaction is completed, add γ-aminopropyltriethoxysilane with a mass 5 times that of the obtained product components and deionized water with a mass 0.8 times that of the obtained product components. After mixing evenly, adjust the pH to 4.8 with acetic acid, then raise the temperature to 70 °C, and keep stirring and reacting at this temperature for 2 h;

[0069] Step 3: After the reaction is completed, remove the low-boiling substances in the reaction product by vacuum distillation, dilute with absolute ethanol and then dehydrate with molecular sieves. The finally obtained product is the organic protective agent; wherein, the temperature of the vacuum distillation is 100 °C, the vacuum degree is 0.1 MPa, and the molecular sieve dehydration time is 30 h.

[0070] Comparative Example 1: The difference from Example 1 is that: in this comparative example, the apparent improver is not used.

[0071] Comparative Example 2: The difference from Example 1 is that: in this comparative example, an equal amount of γ-aminopropyltriethoxysilane is used to replace the organic protective agent.

[0072] Performance test: The following performance tests are respectively carried out on the ultra-thin carrier copper foil samples prepared in Examples 1 to 3 and Comparative Examples 1 to 2:

[0073] 1. Peel strength test: Keep warm for 90 min under the conditions of a pressure of 25 Mpa and a lamination temperature of 220 °C, laminate each group of ultra-thin carrier copper foil samples to be tested on a BT substrate, and cut the laminated ultra-thin carrier copper foil samples into strips of 12.7 mm × 150 mm, and conduct a peeling test using a universal material peeling machine. Use a transmission electron microscope to measure the thickness of the alloy barrier layer, and record the obtained test results in the following table.

[0074] 2. Oxidation resistance: Place each group of ultra-thin carrier copper foil samples to be tested in a constant temperature air-circulating oven and bake at 200 °C and 260 °C for 30 min respectively, and then observe the discoloration or oxidation of the surfaces of each group of ultra-thin carrier copper foil samples to be tested. Record the obtained test results in the following table.

[0075]

[0076]

[0077] By comparing and analyzing the relevant data in the table, it can be seen that the ultra-thin carrier copper foil prepared by the present invention not only has the advantages of low roughness and good smoothness, but also has excellent oxidation resistance, which extends its service life to a certain extent while ensuring its quality. This shows that the preparation process of an ultra-thin carrier copper foil provided by the present invention has a broader market prospect and is more suitable for promotion.

[0078] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0079] 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 the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A preparation process for an ultra-thin carrier copper foil, characterized in that, It includes the following steps: Step 1: At room temperature, pickle the refined and polished carrier foil with sulfuric acid at a concentration of 70-100 g / L. After pickling, wash the carrier foil with deionized water, and then obtain the pretreated carrier foil after vacuum drying treatment. Step 2: Use a pulse electroplating alloy electroplating solution on the smooth surface of the pretreated carrier foil, so as to deposit an alloy barrier layer on the surface of the pretreated carrier foil; then electroplate an ultra-thin layer with a copper sulfate electroplating solution to obtain an ultra-thin copper foil layer with a thickness of 2.9-3.1 μm; the obtained ultra-thin carrier copper foil rough product is stored and reserved for use. Step 3: Coarsely cure the ultra-thin carrier copper foil rough product, and then perform anti-oxidation treatment on it with an anti-oxidation plating solution; among them, the anti-oxidation plating solution contains 15-25 g / L of zinc sulfate and 20-40 g / L of boric acid; and the temperature of the anti-oxidation electroplating solution is 40-50 °C, and the current density during electroplating is set to 2-5 A / dm 2 , and the electro-deposition time is 40-60 s; Step 4: Dissolve the organic protective agent in methanol to prepare an organic protective solution with a concentration of 0.6-2 wt%, then evenly spray it on the surface of the anti-oxidation treated ultra-thin carrier copper foil, and then obtain the finished ultra-thin carrier copper foil after vacuum drying treatment.

2. The preparation process of an ultra-thin carrier copper foil according to claim 1, characterized in that: The carrier foil in Step 1 is a refined and polished copper foil with low roughness, and its roughness is 0.5 ≤ Rz ≤ 0.8 μm.

3. The preparation process of an ultra-thin carrier copper foil according to claim 1, characterized in that, The composition of the alloy electroplating solution includes: 3-6 g / L of molybdenum sulfate, 5-8 g / L of nickel sulfate, 40-60 g / L of cobalt sulfate, 8-15 g / L of boric acid, and 3-5 g / L of benzotriazole.

4. The preparation process of an ultra-thin carrier copper foil according to claim 1, characterized in that: The temperature of the alloy electroplating solution in Step 2 is 45-55 °C, and the pH is 3.8-4.

2.

5. The preparation process of an ultra-thin carrier copper foil according to claim 1, characterized in that, The temperature during the deposition to form the alloy barrier layer is 40 to 45 °C; the current density is 25 to 30 A / dm 2 ; the pulse width is 10 to 20 s; the pulse interval is 10 to 20 s; the total application time of the pulsed current is 50 to 80 s.

6. The preparation process of an ultra-thin carrier copper foil according to claim 1, characterized in that, The composition of the copper sulfate electroplating solution includes: 60-90 g / L of copper sulfate, 100-130 g / L of sulfuric acid, 6-20 mg / L of hydroxyethyl cellulose, 10-40 mg / L of chloride ions, 5-8 g / L of polyethylene glycol, 8-15 g / L of brightener, 3-6 g / L of appearance improver; and the temperature of the copper sulfate electroplating solution is 40-50 °C.

7. The preparation process of an ultra-thin carrier copper foil according to claim 6, characterized in that: The brightener is selected from any one of sodium N,N-dimethyldithiocarbamate, sodium polydithiopropanesulfonate, and sodium 3-mercaptopropanesulfonate.

8. The preparation process of an ultra-thin carrier copper foil according to claim 6, characterized in that, The preparation method of the appearance improver is: put m-phenylene diamine into toluene according to a dosage ratio of 0.2-0.5 g / mL, and then add dimethyl 2,2'-azobis(2-methylpropionate) with a mass of 1.5-2.5% of m-phenylene diamine to it. After mixing and stirring evenly, raise the temperature of the obtained mixed solution to 65-80 °C under the protection of nitrogen, and keep stirring and reacting for 5-8 h; after the reaction is completed, carry out vacuum distillation on the components of the product to remove the toluene in it, and the remaining components are the appearance improver.

9. The preparation process of an ultra-thin carrier copper foil according to claim 1, wherein, The preparation method of the organic protective agent includes the following steps: The first step: Put 2,6-di-tert-butyl-p-cresol and γ-chloropropyltrimethoxysilane into the reaction equipment according to a molar ratio of 1:1-1.5, stir evenly, then add tetrabutylammonium bromide with a mass of 0.8-1.5% of the obtained mixed material, and keep the reaction at a temperature of 80-95 °C for 5-8 h. The second step: After the reaction is completed, add γ-aminopropyltriethoxysilane with a mass of 2-5 times and deionized water with a mass of 0.6-0.8 times to the obtained product components, mix evenly, adjust the pH to 4.3-4.8 with acetic acid, then raise the temperature to 60-70 °C, and keep stirring and reacting at this temperature for 2-5 h. Step 3: After the reaction is completed, remove the low-boiling substances in the reaction product by vacuum distillation, dilute with absolute ethanol and then dehydrate with molecular sieves. The finally obtained product is the organic protective agent.

10. The preparation process of an ultra-thin carrier copper foil according to claim 9, characterized in that: The temperature of the vacuum distillation is 80-100°C, the vacuum degree is 0.08-0.1 MPa, and the dehydration time of the molecular sieve is 25-30 h.

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