KR101386093B1

KR101386093B1 - Copper electrolysis solution for production of electrolytic copper foil, process for producing electrolytic copper foil and electrolytic copper foil

Info

Publication number: KR101386093B1
Application number: KR1020100034390A
Authority: KR
Inventors: 황덕영; 류종호; 송기덕; 양창열; 김상범
Original assignee: 일진머티리얼즈 주식회사
Priority date: 2010-04-14
Filing date: 2010-04-14
Publication date: 2014-04-24
Also published as: WO2011129633A2; KR20110114971A; WO2011129633A3

Abstract

Cl ^- ions; And it comprises a collagen peptide, the number average molecular weight of the collagen peptide is 4,000 to 10,000, the content of the collagen peptide is 0.5 to 20ppm, the copper electrolyte for producing an electrolytic copper foil is 0.5 to 1.5ppm content of Cl-ion is presented.
The copper electrolyte may be easily manufactured and provide a low roughness high strength electrolytic copper foil having excellent thermal stability. The electrolytic copper foil may be used in a current collector of a medium-large lithium ion secondary battery for a hybrid electric vehicle and a semiconductor packing substrate for tape automated bonding (TAB) used in a tape carrier package (TCP).

Description

Copper electrolysis solution for electrolytic copper foil, manufacturing method and electrolytic copper foil {Copper electrolysis solution for production of electrolytic copper foil, process for producing electrolytic copper foil and electrolytic copper foil}

The present invention relates to a copper electrolytic solution for producing an electrolytic copper foil, a method for producing an electrolytic copper foil, and an electrolytic copper foil, and more particularly, a copper electrolyte containing a protein having a predetermined number average molecular weight and excellent thermal stability at a high temperature manufactured using the copper electrolyte. It relates to a low roughness, high strength and high heat resistant electrolytic copper foil.

A copper foil is generally used as a collector for a medium- or large-sized lithium battery for a hybrid electric vehicle (HEV). The copper foil is mainly used for rolling copper foil by rolling, but the manufacturing cost is expensive and it is difficult to manufacture a wide copper foil.

In addition, since the rolled copper foil must use lubricating oil during rolling, adhesion to the active material may be degraded due to contamination of the lubricating oil, thereby degrading charge and discharge cycle characteristics of the battery.

Lithium batteries are accompanied by heat generation due to volume change and overcharge during charging and discharging. In addition, the surface roughness of the copper foil should be low in order to improve the adhesion with the electrode active material. Therefore, a high heat resistance, high strength and low roughness copper foil that can withstand the volume change and exothermic phenomenon of the lithium battery and excellent adhesion to the active material is required.

On the other hand, due to the demand for light and thin components of electronic devices, the demand for fine wiring of a semiconductor mounting board or a main board is increasing to increase the degree of integration of a circuit in a small area due to high functionality, miniaturization, and weight reduction. When a thick copper foil is used in the manufacture of a printed wiring board having such a fine pattern, the etching time for forming the wiring circuit becomes long and the sidewall verticality of the wiring pattern is lowered. In particular, when the wiring line width of the wiring pattern formed by etching is narrow, the wiring may be disconnected. Therefore, in order to obtain a fine pitch circuit, thinner copper foil is calculated | required. However, since the thickness of copper foil is restrict | limited, a thin copper foil has a weak mechanical strength, and the frequency | count of defects, such as wrinkles and a break, at the time of manufacture of a printed wiring board becomes high. Therefore, copper foil with high mechanical strength while being thin in thickness is desired.

One aspect of the present invention is to provide a new copper electrolyte for producing electrolytic copper foil.

Another aspect of the present invention is to provide a method for producing an electrolytic copper foil using the copper electrolytic solution for producing the electrolytic copper foil.

Another aspect of the present invention is to provide an electrolytic copper foil prepared by the above production method.

According to one aspect of the present invention

Cl ^- ions; And collagen peptides;

The number average molecular weight of the collagen peptide is 4,000 to 10,000,

The content of the collagen peptide is 0.5 to 20 ppm,

A copper electrolyte solution for producing an electrolytic copper foil having a content of Cl ⁻ ions of 0.5 to 1.5 ppm is provided.

According to another aspect of the present invention, a copper copper foil production method using the copper electrolytic solution for producing the electrolytic copper foil.

According to another aspect of the present invention, an electrolytic copper foil prepared by the above method is provided.

According to an aspect of the present invention, by using a copper electrolyte containing a protein having a predetermined molecular weight and concentration, an electrolytic copper foil having low surface roughness and improved tensile strength and excellent thermal stability may be obtained.

1 is a scanning electron micrograph of the surface of the electrolytic copper foil prepared in Example 1.
FIG. 2 is a graph showing changes in tensile strength according to changes in annealing temperatures of the electrolytic copper foils of Examples 1 and 5 and Comparative Examples 1, 6 and 9. FIG.

Hereinafter, a copper electrolytic solution for preparing an electrolytic copper foil, a copper copper foil manufacturing method using the copper electrolytic solution, and an electrolytic copper foil manufactured by the manufacturing method according to preferred embodiments will be described in more detail.

Copper electrolyte for preparing an electrolytic copper foil according to an exemplary embodiment is Cl ^- ion; And a collagen peptide; wherein the collagen peptide has a number average molecular weight of 4,000 to 10,000, a content of the collagen peptide is 0.5 to 20 ppm, and a Cl ⁻ ion is 0.5 to 1.5 ppm.

The collagen peptide is a polypeptide prepared by decomposing gelatin extracted from bovine bone, leather, pig bone, leather, produced vinyl, etc., and the raw material is not particularly limited, and the collagen peptide obtained by decomposing all kinds of protein weave Include. The molecular weight of the collagen peptide may be, for example, 4,000 to 10,000. For example, the molecular weight of the collagen peptide may be 5,000 to 8,000.

When the molecular weight of the collagen peptide is less than 4,000, the high temperature tensile strength and elongation may be lowered, and the shape of the acid formed on the precipitated surface may be uneven to increase the roughness of the precipitated surface. If the molecular weight of the collagen peptide is more than 10,000, the room temperature tensile strength and elongation may be lowered, and the shape of the acid formed on the precipitated surface may be uneven to increase the roughness of the precipitated surface.

The concentration of the collagen peptide may be, for example, 0.5 to 15 ppm. For example, the concentration of collagen peptide may be 0.5 to 10 ppm.

When the concentration of the collagen peptide is less than 0.5 ppm, the concentration of the collagen peptide required in the sulfuric acid-copper sulfate may be insufficient, so that the tensile strength may be lowered and the thermal stability at high temperature may be easily lowered. When the concentration of the collagen peptide is more than 20 ppm, copper content is increased and bubbles are generated due to excessively high viscosity of the sulfuric acid-copper sulfate electrolyte, and as a result, many pores are formed in the copper foil, which may cause a decrease in tensile strength.

In the case of an electrolytic copper foil prepared by reduction precipitation on a cathode drum continuously rotated by an electrochemical reaction in an electrolyte, an electrolytic copper foil is manufactured by high-speed plating using a direct current to improve productivity. However, such a high-speed manufacturing method causes a problem that thermal stability at high temperature is significantly lowered due to an increase in residual stress and dislocation density in the deposited electrolytic copper foil. In order to solve this problem, in the present invention, a small amount of Cl ⁻ ions is added to the electrolyte to improve the thermal stability of the electrolytic copper foil.

The presence of a small amount of Cl ^- ions in the electrolyte increases the initial nucleation sites during electroplating, resulting in fine grains, and the precipitation of CuCl ₂ formed at the grain boundary interfaces inhibits crystal growth when heated to high temperatures, thereby improving thermal stability at high temperatures. Improve.

If the concentration of Cl ⁻ ions is less than 0.5 ppm, the concentration of Cl ⁻ ions required in the sulfuric acid-copper sulfate electrolyte may be insufficient, resulting in low room temperature tensile strength and low thermal stability at high temperature. If the concentration of Cl ⁻ ions is more than 1.5 ppm, the surface roughness of the precipitated surface is increased, making it difficult to manufacture low roughness electrolytic copper foil, lowering the tensile strength at room temperature and lowering the thermal stability at high temperature.

As a result, the electrolytic copper foil obtained from the copper electrolyte containing the collagen peptide of the number average molecular weight and the concentration of the above range can be lowered the surface roughness of the precipitation surface and the mechanical strength can be improved.

Copper electrolyte for preparing an electrolytic copper foil according to another exemplary embodiment is a solvent; Cu ²⁺ ions; SO ₄ ^2- ion; Cl ^- ions and collagen peptide; comprising, the number average molecular weight of the collagen peptide is 4,000 to 10,000, the content of the collagen peptide is 0.5 to 20 ppm, the content of Cl ^- ions may be 0.5 to 1.5ppm.

In general, there are two different aspects of copper foil produced by electroplating. There is a polished surface (Shiny side, S surface) in contact with the cathode drum and a matte surface (Mtte side, M surface) in contact with the electrolyte in the direction of crystal grain growth by reduction precipitation. In addition, the surface roughness of the precipitated surface is affected by the surface roughness of the glossy surface, the lower the surface roughness of the glossy surface tends to lower the surface roughness of the precipitated surface. It is preferable that the surface roughness (Rz) of the gloss surface of the electrolytic copper foil manufactured with the said copper electrolyte solution is 1.5 micrometers or less.

In the electrolytic copper foil manufactured from the copper electrolyte, the surface roughness Rz of the precipitation surface M surface may be 1.5 μm or less. For example, the surface roughness of the precipitation surface of the electrolytic copper foil may be 0.5 to 1.5㎛. For example, the surface roughness of the precipitation surface of the electrolytic copper foil may be 0.8 to 1.5㎛. When the surface roughness of the precipitated surface is more than 2.0 μm, the adhesion surface between the surface of the electrodeposited copper foil for the negative electrode current collector and the active material may be reduced, and thus, it may be difficult to maintain the lifetime of the charge and discharge cycle and the high electric capacity at the initial charge.

Room temperature tensile strength of the electrolytic copper foil may be 50 to 70 kg / mm ² . After annealing the electrolytic copper foil at 250 ° C. for 1 hour, the tensile strength after high temperature heat treatment, which is a value of tensile strength, may be 70% or more of room temperature tensile strength. The room temperature tensile strength is the tensile strength at room temperature of the copper foil obtained without high temperature heat treatment.

The concentration of Cu ²⁺ ions in the sulfuric acid-copper sulfate copper electrolyte may be 70 g / L to 150 g / L, but is not necessarily limited thereto, and may be appropriately adjusted within a range capable of achieving the object of the present invention. have. For example, the concentration of Cu ²⁺ may be 85 g / L to 100 g / L.

The concentration of the free SO ₄ ^2- in the sulfuric acid-copper sulfate copper electrolyte is the concentration of SO ₄ ^2- obtained by converting the concentration of Cu ²⁺ in the copper electrolyte into CuSO ₄ , and from the total concentration of SO ₄ ^2- contained in the copper electrolyte. Reduced residual SO ₄ ^2- concentration. The concentration of free SO ₄ ^2- may be 50 g / L to 200 g / L, but is not necessarily limited to this range and may be appropriately adjusted within a range capable of achieving the object of the present invention. For example, the concentration of SO ₄ ^2- may be 80 g / L to 150 g / L.

The copper electrolyte may be prepared by a known method. For example, copper ions can be obtained by adjusting the amount of copper sulfate added, and the concentration of SO ₄ ^2- ions can be obtained by adjusting the amount of sulfuric acid and copper sulfate added. The concentration and molecular weight of the collagen polypeptide contained in the copper electrolyte is obtained from the amount and molecular weight of the collagen polypeptide introduced into the copper electrolyte, or the collagen polypeptide contained in the copper electrolyte is analyzed by a known method such as column chromatography. Can be obtained.

Electrolytic copper foil manufacturing method according to another embodiment of the present invention uses the above-mentioned copper electrolyte for electrolytic copper foil production. The manufacturing method of the electrolytic copper foil can be manufactured by a well-known method except using the said copper electrolyte solution.

For example, the electrolytic copper foil may be manufactured by the following method.

The electrolytic copper foil may be prepared by supplying and electrolyzing a copper electrolyte solution between the curved cathode surface of the rotating titanium drum-shaped titanium and the anode to deposit an electrolytic copper foil on the cathode surface and winding it continuously.

The temperature of the copper electrolyte used in the manufacturing method may be 45 to 65 ℃, but is not necessarily limited to this range can be appropriately adjusted within the range to achieve the object of the present invention. For example, the temperature of the copper electrolyte may be 50 to 60 ℃.

The current density used in the manufacturing method may be 40 to 100A / dm ² , but is not necessarily limited to this range can be appropriately adjusted within the range to achieve the object of the present invention. For example, the current density may be 50 to 80 A / dm ² .

Electrolytic copper foil according to another embodiment of the present invention can be manufactured by the above-described method.

In the electrolytic copper foil manufactured by the above method, the surface roughness Rz of the precipitation surface may be 1.5 μm or less. For example, the surface roughness of the electrolytic copper foil may be 0.5 to 1.5㎛. For example, the surface roughness of the electrolytic copper foil may be 0.8 to 1.5㎛. When the surface roughness of the precipitated surface is more than 1.5 μm, the adhesion surface of the surface of the electrodeposited copper foil for the negative electrode current collector and the active material may become small, and thus, it may be difficult to maintain the lifetime of the charge / discharge cycle and the high electric capacity at the initial charge.

Room temperature tensile strength of the electrolytic copper foil may be 50 to 70 kg / mm ² phosphorus. After annealing the electrolytic copper foil at 250 ° C. for 1 hour, the tensile strength after high temperature heat treatment, which is a value of tensile strength, may be 70% or more of room temperature tensile strength. The room temperature tensile strength is the tensile strength at room temperature of the copper foil obtained without high temperature heat treatment.

Hereinafter, the present invention will be described in further detail with reference to preferred examples, but the present invention is not limited thereto.

(Manufacture of Electrolytic Copper Foil)

Example 1-6 and Comparative Example 1-9

In order to manufacture the electrolytic copper foil by electrochemistry, a 3L capacity electrolytic cell system circulating at 20 L / min was used, and the temperature of the electrolyte was kept constant at 50 ° C. The positive electrode was a 5 mm thick, 10 × 10 cm ² Dimentionally Stable Electrode (DSE) electrode plate, and the negative electrode used a titanium electrode plate having the same size and thickness as the positive electrode. The copper electrolyte solution was prepared as a solution having a composition of Cu ²⁺ concentration of 87.5 g / L and SO ₄ ^2- concentration of 125 g / L. Cl ⁻ ions were added except in Comparative Example 7.

Except for Comparative Example 1, collagen peptide (C & A Biotech, Collagen peptide) was added.

The distance between the electrodes was kept constant at 10cm, in order to facilitate the movement of Cu ²⁺ ions, plating was performed at 60A / dm ² , and electrolytic copper foil having a thickness of 18 μm was prepared. The scanning electron micrograph of the surface of the said electrolytic copper foil is shown in FIG.

The electrolyte solution compositions of Examples 1-6 and Comparative Examples 1-9 are shown in Table 1 below.

thickness
(탆) Temperature
(?) electric current
density
(A / dm ² ) Basic composition Collagen peptide Cu
(g / L) SO ₄ ² ^-
(g / L) Cl
(ppm) Molecular Weight density
(ppm) Example 1 18 50 60 87.5 125 One 7,000 One Example 2 4,000 One Example 3 10,000 One Example 4 7,000 0.5 Example 5 7,000 5 Example 6 7,000 10 Comparative Example 1 - - Comparative Example 2 3,000 One Comparative Example 3 20,000 One Comparative Example 4 7,000 0.05 Comparative Example 5 7,000 30 Comparative Example 6 7,000 50 Comparative Example 7 - 7,000 One Comparative Example 8 2 7,000 One Comparative Example 9 5 7,000 One

Evaluation example 1: surface roughness ( Rz ) Measure

Precipitation surface and gloss surface roughness (Rz) of the electrolytic copper foils obtained in Examples 1 to 6 and Comparative Examples 1 to 9 were measured according to JISB 0601-1994. The surface roughness (Rz) obtained by the measuring method is shown in Table 2 below. Lower values mean lower roughness.

Evaluation Example 2 Measurement of Room Temperature Tensile Strength and Room Temperature Elongation

IPC-TM-650 2.4.18B Specification for tensile test was performed on the electrolytic copper foils obtained in Examples 1 to 5 and Comparative Examples 1 to 8 with a width of 12.7 mm X gauge length of 50 mm and a tensile test at a crosshead speed of 50.8 mm / min. The maximum load of the tensile strength measured and carried out in accordance with the above was called room temperature tensile strength, and the elongation at break was called room temperature elongation. Room temperature tensile strength and room temperature elongation obtained by the measuring method are shown in Table 2 below.

Surface roughness Room temperature tensile strength
[kgf / mm ² ] Room temperature elongation
[%] Precipitation surface (M side)
(Rz) [μm] Glossy side (S side)
(Rz) [μm] Example 1 1.03 1.04 62.43 6.16 Example 2 1.07 1.19 59.97 4.02 Example 3 1.12 1.44 59.74 4.78 Example 4 1.09 1.34 60.15 4.77 Example 5 1.17 1.28 61.07 4.26 Example 6 1.12 1.27 61.17 4.85 Comparative Example 1 1.85 1.79 50.83 2.59 Comparative Example 2 1.78 1.71 51.55 2.61 Comparative Example 3 1.76 1.74 52.51 3.28 Comparative Example 4 1.89 1.75 51.91 2.59 Comparative Example 5 1.98 1.82 47.15 2.01 Comparative Example 6 2.37 1.83 42.18 1.77 Comparative Example 7 1.15 1.81 50.38 1.77 Comparative Example 8 2.63 1.85 48.42 2.25 Comparative Example 9 3.55 1.93 38.29 1.95

As shown in Table 2, the electrolytic copper foils of Examples 1 to 6 had lower surface roughness and higher tensile strength and elongation at room temperature than the electrolytic copper foils of Comparative Examples 1 to 9.

Evaluation Example 3 Measurement of Change in Tensile Strength According to Heat Treatment Temperature

In order to evaluate the thermal stability of the electrolytic copper foil, the electrodeposited copper foils obtained in Examples 1 to 6 and Comparative Examples 1 to 9 were not subjected to heat treatment, or annealing was performed at 100, 150, 200, and 250 ° C. for 1 hour, respectively, and 50.8. Tensile tests were carried out at a crosshead speed of mm / min in accordance with IPC-TM-650 2.4.18B specification and then tensile strength was measured at room temperature. The room temperature is 25 캜.

Tensile strength according to the heat treatment temperature obtained by the measuring method is shown in Table 3 and FIG.

Tensile Strength According to Annealing Temperature (kgf / mm ² ) No heat treatment 100 ℃ 150 ℃ 200 ℃ 250 ℃ Example 1 62.43 56.61 53.52 49.57 48.58 Example 2 59.97 55.41 52.78 48.98 46.77 Example 3 59.74 57.01 53.97 48.87 45.14 Example 4 60.15 55.97 52.41 47.57 46.01 Example 5 61.07 56.44 54.35 55.84 51.59 Example 6 61.17 55.74 53.14 49.75 48.98 Comparative Example 1 50.83 48.53 31.78 27.28 26.29 Comparative Example 2 51.55 44.42 39.52 36.14 29.97 Comparative Example 3 50.54 45.99 43.73 30.14 26.71 Comparative Example 4 51.91 50.11 30.05 25.38 22.94 Comparative Example 5 47.15 46.52 38.24 33.14 29.85 Comparative Example 6 42.18 38.45 30.57 28.74 23.04 Comparative Example 7 50.38 49.49 29.95 26.28 24.01 Comparative Example 8 48.42 47.58 41.31 35.76 31.41 Comparative Example 9 38.29 34.51 36.29 32.21 30.85

As shown in Table 2 and FIG. 2, the electrolytic copper foil of Example 1-6 was subjected to an annealing treatment for 1 hour at 100 to 250 ° C., followed by a tensile test. It was 70% or more of the room temperature tensile strength, but Comparative Example 1-9 was 60% or less. Accordingly, the rate of decrease in tensile strength of the electrolytic copper foil of Example 1-6 was relatively low.

In addition, as shown in FIG. 2, the electrolytic copper foils of Comparative Examples 1, 6, and 9 were very sluggish as the tensile strength was less than 40 after heat treatment at 250 ° C., and in Comparative Example 6, the decrease in tensile strength with the increase of the heat treatment temperature was sharp. . Therefore, the electrolytic copper foil of the comparative examples is inferior in thermal stability, and is unsuitable as an electrical power collector of a lithium battery.

Claims

Cl ^- ions; And collagen peptides;
The number average molecular weight of the collagen peptide is 4,000 to 10,000,
The content of the collagen peptide is 0.5 to 20ppm,
The content of Cl-ion is from 1 to 1.5 ppm,
Copper electrolyte for producing an electrolytic copper foil, the weight ratio of the collagen peptide content and Cl- ion content is 1: 1 ~ 2.

The copper electrolyte of Claim 1 whose surface roughness (Rz) of the precipitation surface of the said electrolytic copper foil is 1.5 micrometers or less.

The copper electrolyte of claim 1, wherein the room temperature tensile strength of the electrolytic copper foil is 50 to 70 kg / mm ² .

The copper electrolyte of claim 1, wherein the electrolytic copper foil is subjected to annealing at 250 ° C. for 1 hour, and the tensile strength after high temperature heat treatment, which is a value of tensile strength, is 70% or more of room temperature tensile strength.

Electrolytic copper foil manufacturing method using the copper electrolyte for electrolytic copper foil manufacture of any one of Claims 1-4.

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