KR101605071B1 - Electrolytic copper foil - Google Patents

Abstract

An electrolytic copper foil having a surface roughness Rz of the precipitated surface of 1.4 m or less, a tensile strength after heat treatment of 40 kgf / mm ² or more and an elongation of 4% or more is presented.
The electrolytic copper foil exhibits a high elongation while maintaining low light intensity and high strength and can be used for a substrate for packing semiconductor chips for TAB (Tape Automated Bonding) used in current collectors of medium and large lithium ion secondary batteries and TCP (Tape Carrier Package) have.

Description

BACKGROUND ART [0002] Electrolytic copper foil

The present invention relates to a copper foil by electrolytic plating, an electric component and a battery including the same, and a manufacturing method thereof, and more particularly, to a copper foil by electrolytic plating, which is excellent in low light intensity, high strength and high elongation electrolytic plating with high tensile strength and elongation, To a copper foil (electrolytic copper foil).

A copper foil is generally used as the current collector of the secondary battery. Although the rolled copper foil by rolling is mainly used for the copper foil, it is difficult to manufacture a copper foil having a high manufacturing cost and a wide width. Further, since the rolled copper foil is required to use lubricating oil during rolling, the adhesion of the rolled copper foil to the active material is lowered due to contamination of the lubricating oil, so that the charge-discharge cycle characteristics of the battery may be deteriorated.

Lithium batteries are accompanied by heat generation due to volumetric change and overcharge during charging and discharging. In addition, in order to improve the adhesion with the electrode active material and to prevent the occurrence of wrinkles and fractures in the copper foil as a current collector due to the influence of the expansion and contraction of the active material layer in the charging and discharging cycles, The illuminance should be low. Therefore, there is a demand for a high-elongation, high-strength, and low-illuminance copper foil which can withstand the volume change of the lithium battery and the heat generation phenomenon and is excellent in adhesion with the active material.

In addition, there is an increasing demand for miniaturization of a semiconductor mounting substrate or a main board substrate in order to increase the degree of integration of a circuit within a small area due to high performance, miniaturization, and lightness due to the requirement for light and small size of electronic devices. If a thick copper foil is used in the production of a printed wiring board having such a fine pattern, the etching time for forming the wiring circuit becomes long and the verticality of the side wall of the wiring pattern is lowered. Particularly, when the wiring line width of the wiring pattern formed by etching is narrow, the wiring can be broken. Therefore, in order to obtain a fine pitch circuit, a thin copper foil is required. However, since the thickness of the copper foil is limited by the thin copper foil, the mechanical strength is weak, and the occurrence frequency of defects such as wrinkling or bending is increased at the time of manufacturing the printed wiring board.

An inner lead disposed in a device hall located at a central portion of a product in a semiconductor packing packing substrate for TAB (Tape Automated Bonding) used in a TCP (Tape Carrier Package) And a plurality of terminals of the semiconductor device are directly bonded. At this time, a current is instantaneously applied using a bonding device to heat and apply a constant pressure. Therefore, the inner lead formed by the etching of the copper foil by the electrolytic plating is stretched by the bonding pressure.

Therefore, a low-illuminance copper foil which is thin in thickness, high in mechanical strength and capable of high-drawing is required.

One aspect of the present invention is to provide a copper foil (electrolytic copper foil) by a new electrolytic plating.

Another aspect of the present invention is to provide an electrical part comprising the copper foil by the electrolytic plating.

Another aspect of the present invention is to provide a battery comprising the copper foil by the electrolytic plating.

Another aspect of the present invention is to provide a method for producing a copper foil by the electrolytic plating.

According to one aspect of the present invention, a copper foil (electrolytic copper foil) by electrolytic plating having a surface roughness Rz of the precipitated surface of 1.4 m or less, a tensile strength after heat treatment of 40 kgf / mm ² or more, and an elongation of 4% or more is presented.

According to another aspect of the present invention, there is provided a semiconductor device comprising: an insulating substrate; And an electrolytic copper foil adhered to one surface of the insulating substrate, wherein the electric part is formed by etching the electrolytic copper foil.

According to still another aspect of the present invention, there is provided a battery including the electrolytic copper foil.

According to another aspect of the present invention, additives A; Additive B; The additive C and the additive D, wherein the additive A is at least one selected from the group consisting of a thiourea compound and a compound in which a thiol group is bonded to a heterocycle containing nitrogen, B is a sulfonic acid or a metal salt thereof of a compound containing a sulfur atom, and the additive C is a nonionic water soluble polymer; And a method of producing copper foil (electrolytic copper foil) by electrolytic plating in which the additive D is a phenazinium compound.

According to one aspect of the present invention, a copper foil can be obtained by electrolytic plating, which has high strength and high elongation while having low surface roughness by using a copper electrolytic solution containing a new composition additive.

Fig. 1 is an X-ray diffraction (XRD) spectrum of the copper foil deposited on the copper foil by electrolytic plating produced in Example 1. Fig.
2 is a scanning electron microscope (SEM) image of the surface of the copper foil by the electrolytic plating produced in Example 1. Fig.
3 is a scanning electron micrograph of the surface of the copper foil by the electrolytic plating produced in Example 2. Fig.
4 is a scanning electron micrograph of the surface of the copper foil by electrolytic plating produced in Example 3. Fig.
5 is a scanning electron micrograph of the surface of the copper foil by electrolytic plating prepared in Example 4. Fig.
6 is a scanning electron microscope (SEM) image of the surface of the copper foil produced by the electrolytic plating produced in Comparative Example 1. Fig.
7 is a scanning electron micrograph of the surface of the copper foil by electrolytic plating produced in Comparative Example 2. Fig.
8 is a scanning electron micrograph of the surface of the copper foil by electrolytic plating produced in Comparative Example 3. Fig.
9 is a scanning electron micrograph of the surface of the copper foil produced by the electrolytic plating produced in Comparative Example 4. Fig.

Hereinafter, a copper foil (electrolytic copper foil) by electrolytic plating according to preferred embodiments, an electric part including the same and a battery, and a method of manufacturing the same will be described in detail.

Electrolytic copper foil (electrolytic copper foil) by plating in accordance with an exemplary embodiment is a surface roughness Rz of the deposited surface 1.4㎛ or less, the heat treatment after the tensile strength of more than 40 kgf / mm ^2, the elongation is 4% or more.

The copper foil (electrolytic copper foil) by electrolytic plating is a low-image-strength copper foil having a surface roughness Rz of 1.4 탆 or less, but has a high tensile strength of 40 kgf / mm ² or more. At the same time, the electrolytic copper foil has a high elongation of 4% or more even after passing through a high temperature.

Therefore, the copper foil (electrolytic copper foil) by electrolytic plating can be used simultaneously for PCB (Printed Circuit Board) / FPC (Flexible PCB) and battery collector.

If the surface roughness Rz of the precipitated surface in the copper foil (electrolytic copper foil) by the electrolytic plating is more than 1.4 mu m, the contact surface between the surface of the electrolytic copper foil for the negative electrode collector and the active material becomes small so that the lifetime of the charge- Can be lowered. If the surface roughness Rz of the precipitation surface is more than 1.4 占 퐉, it is not easy to form a high-density circuit having a fine pitch in the printed wiring board.

The electrolytic copper foil (electrolytic copper foil) by the plating has a tensile strength of high strength characteristics to 40kgf / mm ² to 70kgf / mm ^2. Further, the electrolytic copper foil has a tensile strength is 40kgf / mm ² to 70kgf / mm ² even after the heat treatment. The heat treatment may be performed at, for example, 150 캜 to 220 캜, and more specifically, at 180 캜. The heat treatment can be carried out for 30 minutes, 1 hour, 2 hours and several hours, but a certain tensile strength can be maintained for at least 1 hour. The heat treatment is for measuring the tensile strength of the electrolytic copper foil and is a treatment for obtaining tensile strength or elongation which is maintained at a constant value when the electrolytic copper foil is stored or put into a subsequent process.

When the tensile strength of the copper foil (electrolytic copper foil) by electrolytic plating is less than 40 kgf / mm ² after heat treatment, mechanical strength is weak and handling may be difficult.

The copper foil (electrolytic copper foil) by electrolytic plating is preferably similar in tensile strength after heat treatment to tensile strength before heat treatment. The tensile strength of the electrolytic copper foil after the heat treatment is preferably 85% to 99% of the tensile strength before the heat treatment. If the strength is maintained even after the heat treatment, the handling in the subsequent process becomes easy and the yield increases.

The copper foil (electrolytic copper foil) by electrolytic plating may have an elongation before heat treatment of 2% to 15%. The electrolytic copper foil may have an elongation after heat treatment of 4% to 15%, and the heat treatment may be performed at 180 ° C for 1 hour. Alternatively, the elongation after heat treatment may be 1 to 4.5 times the elongation before heat treatment.

If the elongation after annealing in the copper foil (electrolytic copper foil) by electrolytic plating is less than 4%, a crack may occur in a subsequent process at a high temperature process. For example, when the electrolytic copper foil is used as an anode current collector of a secondary battery, a process for manufacturing an anode current collector is a high-temperature process, and a volume change of the active material layer is accompanied by a change in volume during charging / discharging, Therefore, the predetermined elongation ratio should be maintained after the heat treatment.

The copper foil (electrolytic copper foil) by the electrolytic plating has an intensity I (200) of the diffraction peak with respect to the (200) crystal face and an intensity I (111) of the diffraction peak with respect to the (111) crystal plane in the XRD spectrum with respect to the precipitated face, ) I (200) / I (111) may be 0.5 to 1.0.

For example, as shown in FIG. 1, a diffraction peak with respect to a (111) crystal face is shown at an diffraction angle (2?) Of 43.0 ° ± 1.0 ° in an XRD spectrum with respect to a precipitation plane, and a diffraction angle (2θ) of 50.5 ° ± 1.0 ° And the intensity ratio I (200) / I (111) thereof may be 0.5 to 1.0 or more.

For example, in the electrolytic copper foil, I (200) / I (111) may be 0.5 to 0.8. In the electrolytic copper foil, the orientation index (M (200) (200) / M (111), which is the ratio of the orientation index obtained from the orientation index (M (111)) to the (111) crystal face, may be 1.1 to 1.5. The orientation index is a value obtained by dividing a relative peak intensity of a specific crystal face with respect to an arbitrary sample by a relative peak intensity of a characteristic crystal face obtained from a standard sample having no orientation with respect to all crystal faces. For example, in the electrolytic copper foil, M (200) / M (111) may be 1.2 to 1.4.

The copper foil (electrolytic copper foil) by electrolytic plating may have an elongation of 10% or more after heat treatment at 180 占 폚 for 1 hour. That is, the electrolytic copper foil may have a high elongation after elongation at high temperature of 10% or more. For example, the electrolytic copper foil may have an elongation after hot-heat treatment of 10% to 20%. For example, the electrolytic copper foil may have an elongation after hot-heat treatment of 10% to 15%. For example, the electrolytic copper foil may have an elongation after hot-heat treatment of 10% to 13%. The electrolytic copper foil may have an elongation before heat treatment of 2% or more. For example, the electrolytic copper foil may have an elongation before heat treatment of 2% to 20%. For example, the electrolytic copper foil may have an elongation before heat treatment of 5% to 20%. For example, the electrolytic copper foil may have an elongation before heat treatment of 5% to 15%. For example, the electrolytic copper foil may have an elongation before heat treatment of 5% to 10%. The term "before heat treatment" means 25 ° C. to 130 ° C., which is a temperature before heat treatment at a high temperature. The elongation is a value obtained by dividing the stretched distance until the electrolytic copper foil is broken by the initial length of the electrolytic copper foil.

The copper foil (electrolytic copper foil) by electrolytic plating may have a surface roughness Rz of the precipitated surface of 0.7 mu m or less. The electrolytic copper foil can be used as a copper foil for a PCB / FPC and a copper foil for a negative electrode current collector for a secondary battery by having low light having Rz of 0.7 μm or less. For example, the electrolytic copper foil may have a surface roughness Rz of the precipitated surface of 0.5 mu m or less. For example, the electrolytic copper foil may have a surface roughness Rz of the precipitated surface of 0.45 탆 or less.

The surface roughness Ra of the copper foil (electrolytic copper foil) by electrolytic plating may be 0.15 m or less. The electrolytic copper foil can be used as a copper foil for a PCB / FPC and a copper foil for a negative electrode current collector for a secondary battery by having a low lightness of Ra of 0.15 탆 or less. For example, the electrolytic copper foil may have a surface roughness Ra of the precipitated surface of 0.12 탆 or less. For example, the electrolytic copper foil may have a surface roughness Ra of the precipitated surface of 0.11 탆 or less.

The tensile strength after the heat treatment of the copper foil (electrolytic copper foil) by the electrolytic plating may be 85% or more of the tensile strength before heat treatment. For example, the tensile strength of the electrolytic copper foil after heat treatment at 180 ° C for 1 hour may be 90% or more of the tensile strength before heat treatment. The tensile strength before the heat treatment is the tensile strength of the copper foil obtained without high temperature heat treatment. Before heat treatment the tensile strength of the electrolytic copper foil may be 40kgf / mm ² to 70kgf / mm ^2.

The glossiness (Gs (60)) of the precipitation surface with respect to the width direction in the copper foil (electrolytic copper foil) by the electrolytic plating may be 500 or more. For example, in the electrolytic copper foil, the glossiness (Gs (60)) with respect to the width direction of the precipitation surface may be 500 to 1000. The glossiness is a value measured according to JIS Z 871-1997.

The thickness of the copper foil (electrolytic copper foil) by the electrolytic plating may be 35 탆 or less. For example, the thickness of the electrolytic copper foil may be 6 to 35 mu m. For example, the thickness of the electrolytic copper foil may be 6 to 18 탆. In addition, for example, the thickness of the electrolytic copper foil may be 2 to 10 탆.

When the copper foil (electrolytic copper foil) by electrolytic plating needs to be adhered to an insulating resin or the like, a surface treatment may be additionally performed in order to make the adhesion at a practical level or higher. As the surface treatment on the copper foil, for example, heat treatment and chemical resistance treatment, chromate treatment, silane coupling treatment, or any combination thereof, and the like, and what surface treatment is to be carried out is a resin Those skilled in the art to which the present invention belongs are selected and carried out according to process conditions.

An electrical component according to an exemplary embodiment includes an insulating substrate; And a circuit formed by etching the electrolytic copper foil, the electrolytic copper foil being attached to one surface of the insulating substrate.

The electrical component is not limited to the TAB tape, the printed circuit board (PCB), the flexible printed circuit board (FPC), or the like, and is used by attaching the electrolytic copper foil on the insulating substrate. Anything that can be used in.

A battery according to an exemplary embodiment includes a copper foil (electrolytic copper foil) by the electrolytic plating. The electrolytic copper foil may be used as an anode current collector of the battery, but is not limited thereto and may be used as another component used in a battery. The battery is not particularly limited and includes all primary batteries and secondary batteries, and is a battery that uses an electrolytic copper foil such as a lithium ion battery, a lithium polymer battery, and a lithium air battery as a current collector. It is possible.

A method of manufacturing a copper foil (electrolytic copper foil) by electrolytic plating according to an exemplary embodiment includes the steps of: Additive B; The additive C and the additive D, wherein the additive A is at least one selected from the group consisting of a thiourea compound and a compound in which a thiol group is bonded to a heterocycle containing nitrogen, B is a sulfonic acid or a metal salt thereof of a compound containing a sulfur atom, and the additive C is a nonionic water soluble polymer; The additive D is a phenazinium compound.

The electrolytic copper foil manufacturing method can produce a low-illuminated copper foil having a thin thickness, high mechanical strength and high elongation by containing additives with a novel composition. The copper electrolytic solution may contain chlorine (chlorine ion) at a concentration of 1 to 40 ppm. When a small amount of chlorine ions are present in the copper electrolytic solution, the initial nucleation sites are increased during the electrolytic plating, and the crystal grains become finer and the precipitates of CuCl ₂ formed at the grain boundary interface suppress the crystal growth upon heating at a high temperature, Can be improved. If the concentration of chlorine ions is less than 1 ppm, the concentration of chlorine ions required in the sulfuric acid-copper sulfate-copper electrolytic solution is insufficient, so that the tensile strength before heat treatment may be lowered and the thermal stability at high temperature may be lowered. If the concentration of chlorine ion is more than 40 ppm, the surface roughness of the precipitated surface is increased, so that it is difficult to produce electrolytic copper foil in low light intensity, the tensile strength before heat treatment is lowered and the thermal stability at high temperature may be lowered.

The content of the additive A in the copper electrolytic solution is 1 to 10 ppm, the content of the additive B is 10 to 200 ppm, the content of the additive C is 5 to 40 ppm, and the content of the additive D is 1 to 10 ppm.

In the copper electrolytic solution, the additive A can improve the stabilization of the production of the electrolytic copper foil and improve the strength of the electrolytic copper foil. If the content of the additive A is less than 1 ppm, the tensile strength of the electrolytic copper foil may be lowered. If the content of the additive A is more than 10 ppm, the surface roughness of the precipitated surface may increase, and the electrolytic copper foil of low light intensity may be difficult to produce and the tensile strength may be lowered.

In the copper electrolytic solution, the additive B can improve the surface gloss of the electrolytic copper foil. When the content of the additive B is less than 10 ppm, the brightness of the electrolytic copper foil may be lowered. If the content of the additive B is more than 200 ppm, the surface roughness of the precipitated surface is increased, and the electrolytic copper foil of low light intensity is difficult to manufacture, .

In the copper electrolytic solution, the additive C can lower the surface roughness of the electrolytic copper foil and improve the surface gloss. When the content of the additive C is less than 5 ppm, the surface roughness of the precipitated surface is increased, so that the electrolytic copper foil of low degree is difficult to manufacture and the gloss of the electrolytic copper foil is lowered. If the content of the additive C is more than 40 ppm, It may not be economical.

In the copper electrolytic solution, the additive D can improve the flatness of the surface of the electrolytic copper foil. If the content of the additive D is less than 1 ppm, the surface roughness of the precipitated surface is increased, the electrolytic copper foil of low degree is difficult to produce and the gloss of the electrolytic copper foil may be lowered. If the content of the additive D is more than 40 ppm, the electrolytic copper foil becomes unstable, Can be inhibited.

The thiourea compound may be a compound represented by the following Formula 1:

≪ Formula 1 >

In the above formula, R ¹ , R ² , R ³ and R ⁴ are each independently an alkyl group having 1 to 10 carbon atoms, and R ² and R ⁴ may be connected to each other to form a ring.

For example, the thiourea compound may be selected from the group consisting of diethyl thiourea, ethyl thiourea, acetyl thiourea, dipropyl thiourea, dibutyl thiourea, N-trifluoroacetyl thiourea, N-ethylthiourea, N-cyanoacetylthiourea, N-allylthiourea, o-tolylthiourea, N, N'-butylene N, N'-butylene thiourea, thiazolidinethiol, 4-thiazolinethiol, 4-methyl-2-pyrimidinethiol, 2-thiouracil, but is not limited thereto, and any thiourea compound which can be used as an additive in the technical field is available. The compound in which the thiol group is bonded to the nitrogen-containing heterocycle includes, for example, 2-mercapto-5-benzoimidazole sulfonic acid sodium salt represented by the following formula (2) (5-mercapto-1-tetrazolyl) benzene sulfonate represented by the following formula (3), 2-mercapto (4-mercapto- 2-mercapto benzothiazole. ≪ / RTI >

(2)

(3)

≪ Formula 4 >

The sulfonic acid or its metal salt of the compound containing a sulfur atom includes, for example, a bis (3-sulfopropyl) -disulfide disodium salt (SPS) represented by the following formula (5), a 3-mercapto- (MPS) represented by the following general formula (7), 3- (N, N-dimethylthiocarbamoyl) -thiopropanesulfonate sodium salt (DPS) (3-sulfopropyl) -ester sodium salt (OPX) represented by the following general formula (9), an o-ethyldithiocarbonate sodium salt Sulfonated sodium salt (ZPS), ethylenedithiodipropylsulfonic acid sodium salt, thioglycolic acid, thiophosphoric acid sodium salt, sodium thioglycolate, sodium thioglycolate, sodium thioglycolate, O-ethyl-bis- (omega -sulfopropyl) ester disodium salt (Thiophosphoric acid-O-ethyl-bis- ropyl ester disodium salt and thiophosphoric acid-tris- (omega -sulfopropyl) ester trisodium salt, but it is preferable that these But not limited to, sulfuric acid or a metal salt of a compound including a sulfur atom which can be used as an additive in the technical field.

≪ Formula 5 >

(6)

≪ Formula 7 >

(8)

≪ Formula 9 >

≪ Formula 10 >

*

The nonionic water-soluble polymer may be at least one selected from the group consisting of polyethylene glycol, polyglycerin, hydroxyethyl cellulose, carboxymethylcellulose, nonylphenol polyglycol ether, octane diol-bis (polyalkylene glycol ether) polyalkylene glycol ethers such as bis- (polyalkylene glycol ether), octanol polyalkylene glycol ether, oleic acid polyglycol ether, polyethylene propylene glycol, polyethylene glycol dipentaerythritol dimethyl ether, polyoxypropylene glycol, polyvinyl alcohol,? -naphthol polyglycol ether, stearic acid polyglycol ether, stearyl alcohol Stearyl alcohol polyglycol ether. The polyethylene glycol may have a molecular weight of from 2,000 to 20,000, for example. The water-soluble polymer may be one or more selected from the group consisting of water-soluble polymers.

The phenazinium compound may be a compound represented by the following formula (11): < EMI ID =

≪ Formula 11 >

In this formula,

R ¹ , R ² , R ⁴ , R ⁵ , R ⁶ , R ^{7 '} , R ^{7 "} , R ⁸ And R < ⁹ > independently represent hydrogen, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms, X is selected from the group consisting of -N = NC ₆ H ₄ -N (CH ₃ ) ₂ , hydrogen, Or an aryl group having 6 to 20 carbon atoms, and A is a halogen element. The phenazinium compound is not a polymer.

For example, the phenazinium compound may be at least one selected from the group consisting of safaranine-O represented by the following formula 12 and Janus Green B represented by the following formula 13: .

≪ Formula 12 >

≪ Formula 13 >

The temperature of the copper electrolytic solution used in the above production method may be 30 to 60 캜, but is not necessarily limited to this range and can be appropriately adjusted within the range of achieving the object of the present invention. For example, the temperature of the copper electrolytic solution may be 40 to 50 ° C.

The current density used in the above manufacturing method may be 20 to 500 A / dm ² , but is not necessarily limited to this range and can be appropriately adjusted within the range of achieving the object of the present invention. For example, the current density may be between 30 and 40 A / dm < ² >. The copper electrolytic solution may be a sulfuric acid-copper sulfate copper electrolytic solution. In the copper sulfate-copper sulfate copper solution, the concentration of the Cu ^{2 +} ion may be 60 g / L to 180 g / L, but it is not necessarily limited to this range and can be appropriately controlled within the range of achieving the object of the present invention have. For example, the concentration of Cu ^{2 +} may be from 65 g / L to 175 g / L.

The copper electrolytic solution may be prepared by a known method. For example, the concentration of Cu ^{2 +} ions can be obtained by controlling the addition amount of copper ions or copper sulfate, and the concentration of SO ₄ ^{2 +} ions can be obtained by controlling the addition amount of sulfuric acid and copper sulfate.

The concentration of the additive contained in the copper electrolytic solution can be obtained from the amount and molecular weight of the additive supplied to the copper electrolytic solution or by analyzing the additives contained in the copper electrolytic solution by a known method such as column chromatography.

The electrolytic copper foil can be produced by a known method, except that the above-described copper electrolytic solution is used.

For example, in the electrolytic copper foil, the copper electrolytic solution is supplied and electrolyzed between the cathode surface on the curved surface of titanium on the rotating titanium drum and the anode, and electrolytic copper foil is deposited on the surface of the cathode, and the electrolytic copper foil can be manufactured by continuously winding the electrolytic copper foil.

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

(Manufacture of electrolytic copper foil)

Example 1

A 3L capacity electrolytic cell system capable of circulating at 20L / min was used to produce an electrolytic copper foil by electrolysis, and the temperature of the copper electrolytic solution was kept constant at 45 ° C. The anode was a DSE (Dimensionally Stable Electrode) electrode plate having a thickness of 5 mm and a size of 10 x ¹⁰ cm ² , and the cathode was a titanium electrode plate having the same size and thickness as the anode.

In order to facilitate the movement of Cu ^{2 +} ions, the current density was 35 A / dm ² and the electrolytic copper foil with a thickness of 18 μm was prepared.

The basic composition of the copper electrolyte is as follows:

CuSO ₄ .5H ₂ O: 250 to 400 g / L

H ₂ SO ₄ : 80 to 150 g / L

Chlorine ions and additives are added to the copper electrolytic solution, and the compositions of the additives and chlorine ions added are shown in Table 1 below. In Table 1, ppm is the same as mg / L.

A scanning electron microscope photograph of the surface of the electrolytic copper foil precipitation surface (matte surface, M side) produced is shown in Fig.

Examples 2 to 4 and Comparative Examples 1 to 4

An electrolytic copper foil was prepared in the same manner as in Example 1, except that the composition of the copper electrolytic solution was changed as shown in Table 1 below. Scanning electron micrographs of the surface of the precipitated surface of the electrolytic copper foil produced in Examples 2 to 4 and Comparative Examples 1 to 4 are shown in Figs. 3 to 9, respectively.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Chlorine concentration [ppm] 20 20 20 20 40 40 35 40 DET [ppm] 3 2 3 3 1.5 7 SPS [ppm] 60 45 45 55 55 MPS [ppm] 60 5 20 PEG [ppm] 20 20 20 20 ZPS [ppm] 40 10 40 30 JGB [ppm] 3 SAO [ppm] 3 3 3 2M-SS [ppm] 30 40 DDAC [ppm] 70 70 PGL [ppm] 30 10

Abbreviations in Table 1 mean the following compounds.

DET: diethylthiourea

SPS: bis- (3-sulfopropyl) -disulfide

MPS: 3-mercapto-1-propanesulfonic acid

PEG: polyethylene glycol (Kanto Chemical Cas No. 25322-68-3)

ZPS: 3- (benzothiazolyl-2-mercapto) -propyl-sulfonic acid sodium salt

JGB: Janus Green B

2M-SS; 2-mercapto-5-benzoimidazole sulfonic acid

DDAC: diallyldimethylammonium chloride

PGL: Polyglycerin (KCI, PGL 104KC)

Evaluation Example 1: Scanning electron microscope experiment

The surface of the precipitated surface of the electrolytic copper foil obtained in Examples 1 to 4 and Comparative Examples 1 to 4 was measured by a scanning electron microscope and the results are shown in Figs. 2 to 9, respectively.

 As shown in Figs. 2 to 9, the electrolytic copper foils of Examples 1 to 4 had a flat surface and lower illuminance than the electrolytic copper foils of Comparative Examples 1 to 4.

Evaluation example 2: gloss measurement

The glossiness was measured on the surface of the precipitated surface of the electrolytic copper foil obtained in Examples 1 to 4 and Comparative Examples 1 to 4. The glossiness is a value measured according to JIS Z 871-1997.

 The glossiness was measured by measuring the intensity of the light reflected at a reflection angle of 60 占 by irradiating the surface of the copper foil with the measuring light at an incident angle of 60 占 along the flow direction of the electrolytic copper foil (MD direction) 8741-1997.

 The measurement results are shown in Table 2 below.

Glossiness [Gs (60 °)] Example 1 700 Example 2 699 Example 3 630 Example 4 680 Comparative Example 1 438 Comparative Example 2 472 Comparative Example 3 353 Comparative Example 4 451

As shown in Table 2, the electrolytic copper foils of Examples 1 to 4 exhibited improved gloss compared to the electrolytic copper foils of Comparative Examples 1 to 4.

Evaluation Example 3: XRD experiment

XRD (X-ray diffraction) spectra of the precipitated surfaces of the electrolytic copper foils obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were measured. The XRD spectrum for Example 1 is shown in FIG.

 As shown in FIG. 1, the peak intensity of the (111) crystal face was the highest, and the following was the (200) crystal face.

 I (200) / I (111), which is the ratio of the intensity (I (200)) of the diffraction peak to the (200) crystal face and the intensity (I (111)) of the diffraction peak with respect to the (111) crystal face, was 0.605.

 The orientation index (M) for the (111), (200), (220), (311) and (222) crystal planes in the XRD spectrum of the precipitated surface was measured, Respectively.

The orientation indices are S. Yoshimura, S. Yoshihara, T.Shirakashi, E. Sato, Electrochim. (M) proposed by Acta 39, 589 (1994).

For example, in the case of a specimen having a (111) plane, an orientation index (M) is calculated in the following manner.

IF (111) = IF (111) / IF (111) + IF (200) + IF (220) + IF (311)

IR (111) = I (111) / {I (111) + I (200) + I (220) + I (311)

M (111) = IR (111) / IFR (111)

IF (111) is the XRD intensity in the JCPDS cards and I (111) is the experimental value. When M (111) is larger than 1, it has a preferential orientation parallel to the (111) plane, and when M is smaller than 1, it means that the orientation decreases first.

Crystal plane (111) (200) (220) (311) (222) Orientation index 1.02 1.34 0.80 0.25 0.97

With reference to Table 3, the ratio of the orientation index M (200) to the (200) crystal face and the orientation index M (111) to the (111) crystal face in the XRD spectrum of the precipitated face M (200) / M (111) was 1.31.

 Evaluation Example 4: Measurement of surface roughness (Rz)

 The surface roughness Rz and Ra of the precipitated surface and the gloss surface of the electrolytic copper foil obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were measured according to the JIS B 0601-1994 standard. The surface roughnesses Rz and Ra obtained by the above measurement method are shown in Table 4 below. The lower the value, the lower the roughness.

Evaluation Example 5: Measurement of room temperature tensile strength, room temperature elongation, high temperature tensile strength and high temperature elongation

The tensile test specimens were taken from the electrolytic copper foils obtained in Examples 1 to 4 and Comparative Examples 1 to 4 at a width of 12.7 mm and a gauge length of 50 mm. The tensile test was carried out at a crosshead speed of 50.8 mm / min using the IPC-TM-650 2.4.18B standard , The maximum load of the tensile strength measured at room temperature is referred to as room temperature tensile strength and the elongation at break is referred to as room temperature elongation. The room temperature is 25 ° C.

The same electrolytic copper foil as that used in measuring the tensile strength and elongation at room temperature was taken out after heat treatment at 180 ° C for 1 hour, and the tensile strength and elongation were measured in the same manner as above, and were referred to as high temperature tensile strength and high temperature elongation.

The room temperature tensile strength, the room temperature elongation, the high temperature tensile strength and the high temperature elongation obtained by the above measuring method are shown in Table 4 below.

Precipitation surface
Surface roughness Room temperature tensile strength
[kgf / mm ² ] Room temperature elongation
[%] High temperature tensile strength
[kgf / mm ² ] High temperature elongation
[%] Rz
[Mu m] Ra
[Mu m] Example 1 0.30 0.08 46.15 7.21 43.30 11.63 Example 2 0.28 0.07 42.28 5.00 40.16 12.06 Example 3 0.38 0.10 45.41 6.16 41.55 9.38 Example 4 0.44 0.11 44.74 6.62 40.78 10.53 Comparative Example 1 0.67 0.16 86.65 2.18 77.91 3.30 Comparative Example 2 0.48 0.10 98.76 1.30 92.30 1.74 Comparative Example 3 1.46 0.24 52.81 1.64 49.53 1.87 Comparative Example 4 1.38 0.25 70.73 1.71 64.30 1.47

As shown in Table 4, the electrolytic copper foils of Examples 1 to 4 had low surface roughness Rz of less than 0.5 占 퐉, tensile strength after high-temperature heat treatment of not less than 40 kgf / mm ² , and elongation after high temperature heat treatment, .

On the other hand, the electrolytic copper foils of Comparative Examples 1 to 4 had higher surface roughness and lower elongation after high-temperature heat treatment as compared with the electrolytic copper foils of Examples 1 to 4, so that they were used as a negative electrode current collector for a secondary battery and / Lt; / RTI >

The present invention is not to be limited by the above-described embodiments and the accompanying drawings, but should be construed according to the appended claims. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (25)

I (200) / I (111) which is the ratio of the intensity (I (200)) of the diffraction peak to the (200) crystal face and the intensity (I ) Is 0.5 to 1,
The surface roughness Rz of the precipitated surface is 1.4 占 퐉 or less,
A tensile strength after heat treatment of not less than 40 kgf / mm ² , an elongation of not less than 4%
M (200) / M (200) which is the ratio of the orientation index (M (200)) to the (200) crystal plane and the orientation index (M 111) is 1.1 to 1.5.
The method according to claim 1,
Before heat treatment has a tensile strength of 40kgf / mm ² to 70kgf / mm ² of electrolytic copper foil.
The method according to claim 1,
After the heat treatment the tensile strength was 40kgf / mm ² to 70kgf / mm ² of electrolytic copper foil.
The method of claim 3,
At 180 ℃ after 1 hour heat treatment the tensile strength of 40kgf / mm ² to 70kgf / mm ² of electrolytic copper foil.
The method according to claim 1,
The tensile strength after heat treatment is 85% to 99% of the tensile strength before heat treatment.
The method according to claim 1,
An electrolytic copper foil having an elongation of 2% to 15% before heat treatment.
The method according to claim 1,
An electrolytic copper foil having an elongation after heat treatment of 4% to 15%.
8. The method of claim 7,
And an elongation rate of 4% to 15% after heat treatment at 180 占 폚 for 1 hour.
The method according to claim 1,
The elongation after heat treatment is 1 to 4.5 times the elongation before heat treatment.
delete The method according to claim 1,
And the surface roughness Rz of the precipitation surface is 0.7 占 퐉 or less.
The method according to claim 1,
Wherein the precipitated surface has a surface roughness Ra of 0.15 占 퐉 or less.
The method according to claim 1,
(Gs (60 DEG)) of the precipitation surface with respect to the width direction is 500 or more.
The method according to claim 1,
An electrolytic copper foil having a thickness of 2 탆 to 10 탆.
Insulating substrate; And
An electrolytic copper foil according to any one of claims 1 to 9 and 11 to 14 attached to one surface of the insulating base material,
And a circuit formed by etching the electrolytic copper foil.
A battery comprising an electrolytic copper foil according to any one of claims 1 to 9 and 11 to 14.
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