An additive for ultra-thick electrolytic copper foil, ultra-thick electrolytic copper foil and preparation process thereof

Abstract

The present invention belongs to the technical field of electrolytic copper foil production, and the present invention provides an additive for ultra-thick electrolytic copper foil, an ultra-thick electrolytic copper foil and a preparation process thereof. The additive comprises the following components: aspartic acid, 2-mercaptopyridine, gelatin, sodium polydisulfide dipropane sulfonate, polyvinyl alcohol and water. The present invention also provides a preparation process for ultra-thick electrolytic copper foil using the above-mentioned additive, comprising the following steps: S1, adding a copper block to a sulfuric acid solution for reaction to generate a copper sulfate electrolyte; S2, adding the additive to a copper sulfate solution for electrolysis to produce a super-thick electrolytic copper foil. The ultra-thick electrolytic copper foil prepared by the present invention not only ensures its own thickness, but also ensures its own strength. It will not easily become loose due to uneven sticking due to excessive thickness of the body, thereby extending its service life and meeting the needs of high-end circuit boards.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic copper foil production, and in particular to an additive for ultra-thick electrolytic copper foil, an ultra-thick electrolytic copper foil and a preparation process thereof. Background Art

[0002] Electrolytic copper foil refers to a metal copper foil produced by electrolysis using copper as the main raw material. The copper material is dissolved to form a copper sulfate electrolytic solution, which is then deposited by direct current in a special electrolytic device to form foil. The foil is then subjected to a series of treatments such as surface roughening and anti-oxidation treatment, and finally cut and tested to form a finished product.

[0003] According to different application fields, electrolytic copper foil can be divided into lithium battery copper foil and standard copper foil; according to the thickness of copper foil, it can be divided into ultra-thin copper foil, ultra-thin copper foil, thin copper foil, conventional copper foil and thick copper foil; according to the surface condition, it can be divided into double-sided smooth copper foil, double-sided rough copper foil, double-sided rough copper foil, single-sided rough copper foil and very low profile copper foil (VLP copper foil).

[0004] The quality and stability of electrolytic copper foil products mainly depend on the formula and addition method of additives. There are many formulas for electrolytic copper foil additives, and different formulas can adjust different product grain structures. However, most of the existing additives are only suitable for the preparation of electrolytic copper foil below 200 microns, which cannot meet the needs of high-end circuit boards.

[0005] Therefore, providing an additive for use in an ultra-thick electrolytic copper foil and a preparation process for the ultra-thick electrolytic copper foil has become an urgent problem to be solved by those skilled in the art. Summary of the invention

[0006] In view of this, the present invention provides an additive for ultra-thick electrolytic copper foil and an ultra-thick electrolytic copper foil and a preparation process thereof, which aims to solve the technical problem that the existing electrolytic copper foil cannot meet the requirements of high-end circuit boards due to its too thin thickness.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] The invention provides an additive for ultra-thick electrolytic copper foil, comprising the following components in parts by weight: 1-10 parts of aspartic acid, 1-10 parts of 2-mercaptopyridine, 0.1-5 parts of gelatin, 1-5 parts of sodium polydisulfide dipropane sulfonate, 1-5 parts of polyvinyl alcohol, and 50-80 parts of water.

[0009] The present invention provides a preparation process for ultra-thick electrolytic copper foil using the above-mentioned additive, comprising the following steps:

[0010] S1, adding copper blocks into sulfuric acid solution to react and generate copper sulfate electrolyte;

[0011] S2. Adding additives into copper sulfate solution for electrolytic production of foil to obtain ultra-thick electrolytic copper foil.

[0012] Furthermore, in step S1, the concentration of the sulfuric acid solution is 70-90 g / L.

[0013] Furthermore, in step S1, the purity of the copper block is ≥99.5%.

[0014] Furthermore, in step S1, the concentration of copper ions in the copper sulfate electrolyte is 80-100 g / L, and the concentration of chloride ions is 40-60 ppm.

[0015] Furthermore, in step S1, the temperature of the copper sulfate electrolyte is 40-60°C.

[0016] Furthermore, in step S2, the process conditions for electrolytic foil production are: electrolytic current is 15000-18000A, cathode roller linear speed is 0.2-0.5m / min, and the flow rate of copper sulfate electrolyte is 20-50m / min. 3 / h, the flow rate of additive is 8~15L / h.

[0017] The invention provides an ultra-thick electrolytic copper foil prepared by the above preparation process.

[0018] Furthermore, the thickness of the ultra-thick electrolytic copper foil is ≥200 microns.

[0019] It can be seen from the above technical solution that compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] In the present invention, aspartic acid can hinder the reduction of copper ions and slow down the contour fluctuation of the copper foil surface, thereby smoothing the microscopic contour of the copper foil surface and reducing the surface roughness; 2-mercaptopyridine can be selectively adsorbed on a specific crystal plane on the surface of the deposited layer, hindering the unidirectional growth of crystals, inhibiting conical or blocky growth, and refining grains. After the combined action of aspartic acid, the prepared copper foil has the characteristics of smoothness, fine crystals and brightness; polyvinyl alcohol not only improves the tensile properties of the copper foil, but also does not affect the gloss of the copper foil.

[0021] The preparation process of the electrolytic copper foil provided by the present invention is simple to operate and low in cost. The prepared electrolytic copper foil not only ensures its own thickness, but also ensures its own strength. It will not easily become loose due to uneven sticking due to excessive thickness of the body, thereby extending its service life. It also has the advantages of good thickness uniformity, high purity and good conductivity, and can meet the needs of high-end circuit boards. DETAILED DESCRIPTION

[0022] The invention provides an additive for ultra-thick electrolytic copper foil, comprising the following components in parts by weight: 1-10 parts of aspartic acid, 1-10 parts of 2-mercaptopyridine, 0.1-5 parts of gelatin, 1-5 parts of sodium polydisulfide dipropane sulfonate, 1-5 parts of polyvinyl alcohol, and 50-80 parts of water.

[0023] In the present invention, the amount of aspartic acid is preferably 2 to 8 parts, more preferably 3 to 6 parts.

[0024] In the present invention, the amount of 2-mercaptopyridine is preferably 2 to 8 parts, more preferably 3 to 6 parts.

[0025] In the present invention, the amount of gelatin used is preferably 1 to 4 parts, more preferably 2 to 3 parts.

[0026] In the present invention, the amount of the sodium polydipropylene sulfonate is preferably 2 to 4 parts, more preferably 3 parts.

[0027] In the present invention, the amount of polyvinyl alcohol used is preferably 2 to 4 parts, more preferably 3 parts.

[0028] In the present invention, the amount of water used is preferably 55 to 75 parts, more preferably 60 to 70 parts.

[0029] The present invention provides a preparation process for ultra-thick electrolytic copper foil using the above-mentioned additive, comprising the following steps:

[0030] S1, adding copper blocks into sulfuric acid solution to react and generate copper sulfate electrolyte;

[0031] S2. Adding additives into copper sulfate solution for electrolytic production of foil to obtain ultra-thick electrolytic copper foil.

[0032] In the present invention, in step S1, the concentration of the sulfuric acid solution is 70 to 90 g / L, preferably 75 to 88 g / L, and more preferably 80 to 85 g / L.

[0033] In the present invention, in step S1, the purity of the copper block is ≥99.5%, preferably ≥99.6%, and more preferably ≥99.8%.

[0034] In the present invention, in step S1, the concentration of copper ions in the copper sulfate electrolyte is 80-100 g / L, preferably 82-96 g / L, and more preferably 85-92 g / L; the concentration of chloride ions is 40-60 ppm, preferably 42-56 ppm, and more preferably 45-55 ppm.

[0035] In the present invention, in step S1, the temperature of the copper sulfate electrolyte is 40-60°C, preferably 44-58°C, and more preferably 48-52°C.

[0036] In the present invention, in step S2, the process conditions for electrolytic foil production are: electrolytic current is 15000-18000A, preferably 15500-17500A, and more preferably 16000-17000A; cathode roller linear speed is 0.2-0.5m / min, preferably 0.3-0.4m / min; copper sulfate electrolyte flow rate is 20-50m / min 3 / h, preferably 25 to 45 m 3 / h, more preferably 30 to 40m 3 / h; the flow rate of the additive is 8 to 15 L / h, preferably 10 to 14 L / h, and more preferably 11 to 12 L / h.

[0037] In the present invention, the ultra-thick electrolytic copper foil obtained in step S2 is subjected to chromic anhydride passivation treatment, and the content of chromic anhydride in the solution used is 2 to 5 g / L, preferably 3 to 4 g / L.

[0038] The invention provides an ultra-thick electrolytic copper foil prepared by the above preparation process.

[0039] In the present invention, the thickness of the ultra-thick electrolytic copper foil is ≥200 microns, preferably ≥220 microns, and more preferably 240 microns, 300 microns or 400 microns.

[0040] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0041] Example 1

[0042] The additives used in this embodiment are as follows: 8 parts of aspartic acid, 5 parts of 2-mercaptopyridine, 2 parts of gelatin, 2 parts of sodium polydisulfide propane sulfonate, 3 parts of polyvinyl alcohol, and 58 parts of water.

[0043] The preparation process of the ultra-thick electrolytic copper foil using the above additives comprises the following steps:

[0044] The copper block is added into a sulfuric acid solution with a concentration of 90 g / L to react, and a copper sulfate electrolyte with a copper ion concentration of 90 g / L is generated, wherein the copper sulfate electrolyte also contains 50 ppm of chloride ions; the additive is added into the copper sulfate solution to electrolyze the foil to obtain the ultra-thick electrolytic copper foil, and the process conditions of the electrolytic foil are: the electrolysis current is 16000A, the cathode roller linear speed is 0.3 m / min, and the flow rate of the copper sulfate electrolyte is 30 m 3 / h, the flow rate of the additive is 10L / h; the obtained ultra-thick electrolytic copper foil is subjected to chromic anhydride passivation treatment.

[0045] After inspection and testing, the 400-micron ultra-thick electrolytic copper foil manufactured using the above production process has a room-temperature tensile strength of 400 MPa, a room-temperature elongation of 28%, a surface roughness Rz value of 3.25 μm, and oxidation resistance: no oxidative discoloration (160°C / 30min).

[0046] Example 2

[0047] The additives used in this embodiment are as follows: 6 parts of aspartic acid, 4 parts of 2-mercaptopyridine, 3 parts of gelatin, 3 parts of sodium polydisulfide propane sulfonate, 2 parts of polyvinyl alcohol, and 60 parts of water.

[0048] The preparation process of the ultra-thick electrolytic copper foil using the above additives comprises the following steps:

[0049] The copper block is added into a sulfuric acid solution with a concentration of 80 g / L to react, and a copper sulfate electrolyte with a copper ion concentration of 92 g / L is generated, wherein the copper sulfate electrolyte also contains 55 ppm of chloride ions; the additive is added into the copper sulfate solution to electrolyze the foil to obtain the ultra-thick electrolytic copper foil, and the process conditions of the electrolytic foil are: the electrolysis current is 17000A, the cathode roller linear speed is 0.4 m / min, and the flow rate of the copper sulfate electrolyte is 35 m 3 / h, the flow rate of the additive is 12L / h; the obtained ultra-thick electrolytic copper foil is subjected to chromic anhydride passivation treatment.

[0050] After inspection and testing, the 260-micron ultra-thick electrolytic copper foil manufactured using the above production process has a room-temperature tensile strength of 320 MPa, a room-temperature elongation of 26%, a surface roughness Rz value of 3.11 μm, and oxidation resistance: no oxidative discoloration (160°C / 30min).

[0051] Example 3

[0052] The additives used in this embodiment are as follows: 4 parts of aspartic acid, 6 parts of 2-mercaptopyridine, 1 part of gelatin, 1 part of sodium polydisulfide propane sulfonate, 4 parts of polyvinyl alcohol, and 70 parts of water.

[0053] The preparation process of the ultra-thick electrolytic copper foil using the above additives comprises the following steps:

[0054] The copper block is added to a sulfuric acid solution with a concentration of 88 g / L to react, and a copper sulfate electrolyte with a copper ion concentration of 92 g / L is generated, wherein the copper sulfate electrolyte also contains 45 ppm of chloride ions; the additive is added to the copper sulfate solution to electrolyze the foil to obtain an ultra-thick electrolytic copper foil, and the process conditions for the electrolytic foil are: the electrolysis current is 16000A, the cathode roller linear speed is 0.5 m / min, and the flow rate of the copper sulfate electrolyte is 40 m 3 / h, the flow rate of the additive is 11L / h; the obtained ultra-thick electrolytic copper foil is subjected to chromic anhydride passivation treatment.

[0055] After inspection and testing, the 300-micron ultra-thick electrolytic copper foil manufactured using the above production process has a room-temperature tensile strength of 350 MPa, a room-temperature elongation of 27%, a surface roughness Rz value of 3.15 μm, and oxidation resistance: no oxidative discoloration (160°C / 30min).

[0056] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0057] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An additive for ultra-thick electrolytic copper foil, characterized in that: The invention is composed of the following components in parts by weight: 1 to 10 parts of aspartic acid, 1 to 10 parts of 2-mercaptopyridine, 0.1 to 5 parts of gelatin, 1 to 5 parts of sodium polydisulfide dipropane sulfonate, 1 to 5 parts of polyvinyl alcohol and 50 to 80 parts of water.

2. A process for preparing ultra-thick electrolytic copper foil using the additive according to claim 1, characterized in that: The following steps are involved: S1, adding copper blocks into sulfuric acid solution to react and generate copper sulfate electrolyte; S2. Adding additives into copper sulfate solution for electrolytic production of foil to obtain ultra-thick electrolytic copper foil.

3. The preparation process according to claim 2, characterized in that: In the step S1, the concentration of the sulfuric acid solution is 70-90 g / L.

4. The preparation process according to claim 3, characterized in that: In the step S1, the purity of the copper block is ≥99.5%.

5. The preparation process according to claim 3 or 4, characterized in that: In step S1, the concentration of copper ions in the copper sulfate electrolyte is 80-100 g / L, and the concentration of chloride ions is 40-60 ppm.

6. The preparation process according to claim 5, characterized in that: In step S1, the temperature of the copper sulfate electrolyte is 40-60°C.

7. The preparation process according to claim 2, 4 or 6, characterized in that: In step S2, the process conditions for electrolytic foil production are: electrolytic current is 15000-18000A, cathode roller linear speed is 0.2-0.5m / min, and the flow rate of copper sulfate electrolyte is 20-50m / min. 3 / h, the flow rate of additive is 8~15L / h.