KR100389061B1 - Electrolytic copper foil and process producing the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic solution used to prepare an electrolytic copper foil for secondary battery electrode collectors and printed circuits, wherein, based on 1 liter of electrolytic solution, a disulfur compound and a dialkylamino-thioxomethyl-thioalkanesulfonic acid or salts thereof 0.5 to 40 mg of sulfur-containing compound having at least one selected, at least one organic compound selected from the group consisting of 1 to 1000 mg of polyalkylene glycol-based surfactant and low molecular gelatin and 0.1 to 80 mg of chlorine ion It was made to contain.

Delivered according to the present invention, the copper foil in the case of electrolytic copper foil of jebak state where the roughness R _z value of the rough surface has a range of less than 2.0 ㎛, a functionalized electrolysis for copper foil has a roughness R _z value of the rough side 1.0 ~ 3.5 ㎛ It will have a value within. Since the roughness value of a glossy surface changes with polishing of a cathode surface, it has a characteristic which is not specifically limited.

Description

ELECTROLYTIC COPPER FOIL AND PROCESS PRODUCING THE SAME

The present invention relates to an electrolytic solution used to manufacture an electrolytic copper foil for a printed circuit and an electrolytic copper foil for an electrode current collector of a secondary battery, and a method for producing an electrolytic copper foil and an electrolytic copper foil using the same.

Printed circuit boards using electrolytic copper foil are widely used as precision control circuits for various electrical and electronic communication devices such as radios, TVs, computers, telephone exchanges, and wireless transceivers. In recent years, as the degree of integration of printed circuit boards increases, circuits of substrates have been miniaturized and multilayered. In particular, the demand for electrolytic copper foil is rapidly increasing in COF (Chip On Flex), TAB (Tape Automatic Bonding), etc., and its physical properties are improved, and thus it is widely used as an electrode current collector for secondary batteries.

Electrolytic copper foil is typically produced by electrolysis and includes a cylindrical anode made of titanium (also called a drum) and a lead alloy shaped at regular intervals or an anode made of titanium coated with iridium oxide, an electrolyte, and a current source. It is prepared in an electrolytic cell. The electrolyte is made of sulfuric acid and / or copper sulfate, and when a direct current flows between the cathode and the anode while rotating the cylindrical cathode, copper is electrodeposited on the cathode to enable continuous electrolytic copper foil production. In this way, a process of reducing copper ions to metal by an electrolysis method is called a milling process.

Next, the copper copper foil obtained in the manufacturing process is subjected to a rough treatment process (also referred to as a Nodule treatment process), a diffusion preventing treatment to prevent diffusion of copper ions, and to prevent oxidation from the outside in order to improve adhesion to the insulating substrate, if necessary. It may be subjected to an additional surface treatment process such as antirust treatment, chemical adhesion enhancement treatment to complement the adhesion with the insulating substrate. Through the surface treatment process, it becomes a copper foil for low profile printed circuits, and it becomes a copper foil for secondary batteries if only rust prevention treatment is performed in the surface treatment process.

Electrodeposited copper foil, when used for printed circuits, is surface-treated and then supplied to PCB (Printed Circuit Board) manufacturers in the form of laminates (laminates) with insulating substrates. In contrast, when used for a secondary battery, it is supplied to a secondary battery generating company only through rust prevention treatment.

Copper foil suitable for fine and highly integrated PCB circuits requires that the roughness of the bonding surface with the insulating substrate be small. In addition, in the process of bonding the electrolytic copper foil on the insulating substrate, stress is applied to the copper foil by thermal expansion or contraction of the insulating substrate, and furthermore, when the copper foil is laminated in multiple layers, scratches may occur due to friction with adjacent copper foils. In severe cases, the copper foil may be peeled off from the insulating substrate, or the circuit may be broken or the printed circuit board may be bent or distorted. In order to become a copper foil which does not have such a problem, it is required to have an appropriate elongation without sharply decreasing mechanical strength at high temperature.

When using an electrolytic copper foil as an electrical power collector for secondary batteries, an electrode material is coat | covered and used for both surfaces of copper foil. In this case, when the roughness of both surfaces of the electrolytic copper foil is different, the battery characteristics vary depending on the surface, and therefore, it is necessary to maintain the same or similar level of roughness of both surfaces of the electrolytic copper foil. In addition, in order to reduce the weight and manufacturing cost of the battery and to increase the energy density of the battery, it may be required to manufacture the thickness of the electrolytic copper foil in a thin form, and even in the case of a thin film, it has sufficient mechanical strength and elongation at high temperatures, such as not bending in a subsequent treatment process. It is necessary.

In the prior art, in order to satisfy these demands, a method of making an electrolytic copper foil by adding various organic additives to an electrolyte solution has been proposed. As a representative example, U. S. Patent No. 5,431, 803 has been proposed to lower the surface roughness, and discloses a method for producing an electrolytic copper foil having a feature of maintaining the chlorine ion concentration in 1 liter of the electrolyte at 1 mg or less. However, the electrolytic copper foil manufactured by the technique proposed in US Pat. No. 5,431,803 has a mechanical strength of 61 kgf / mm 2 to 84 kgf / mm 2 at room temperature and 17 kgf / mm 2 to 25 kgf / mm 2 at 180 ° C. The surface roughness Rmax is about 6 µm, which is not suitable for secondary batteries. In addition, there is a disadvantage that it is difficult to continuously work while maintaining the concentration of chlorine ions in the electrolyte solution to 1 mg or less.

Accordingly, an object of the present invention is to solve the problems of the prior art, and it is possible to adjust the roughness of both sides of the electrodeposited copper foil according to the electrolyte additive, or to adjust the amount of the electrolyte additive together with the ambient temperature even at a high temperature. the abrupt intensity change is the same Marine electrolyte, electrolysis for that printed circuit occur as compared to provide an electrolytic copper foil and the production method using the production by using this. a further object is roughness R _z value of the rough surface in jebak aspect of the present invention The present invention provides an electrolytic solution used to produce an electrolytic copper foil having a range within the range of 2.0 µm and which does not cause a sharp change in strength even at a high temperature, and an electrolytic copper foil produced using the same and an electrolytic copper foil production method using the same.

The above object of the present invention is an electrolytic solution for producing an electrolytic copper foil, and at least one selected from a disulfur compound, a dialkylamino-thioxomethyl-thioalkanesulfonic acid and a dialkylamino-thioxomethyl-thioalkanesulfone salt based on 1 liter of an electrolyte Sulfur-containing compounds of 0.5 to 40 mg of sulfur-containing compounds, polyalkylene glycol-based surfactants and at least one kind selected from the group consisting of low molecular gelatin and 1 to 1000 mg of organic compounds and 0.1 to 80 mg of chlorine ions It can achieve by the electrolyte solution to contain, the electrolytic copper foil produced using such electrolyte solution, and the electrolytic copper foil manufacturing method using the same.

Generally, the manufacturing process of the electrolytic copper foil for a printed circuit is divided into a manufacturing process and a surface treatment process.

The crushing process is generally accomplished using an electroforming cell. In the electrolytic cell, a semi-cylindrical positive electrode and a rotating cylindrical negative electrode maintain a constant interval therebetween, and electrolyte solution is continuously supplied therebetween. By flowing a DC current between the positive electrode and the negative electrode, copper ions in the electrolyte are reduced to a metal having a predetermined thickness at the negative electrode. Next, the copper foil (untreated copper foil) which has not undergone the subsequent treatment step comes off from the cathode surface. Lead alloys are used a lot, but recently lead titanium is coated with iridium oxide because lead oxide is worn out and the gap is changed. The cathode may be used by chromium plating on iron, but recently, titanium is coated on stainless steel to prolong its service life.

Further processing can be carried out through the processor on the untreated copper foil to provide the required properties as required. This treatment process includes a roughening treatment to improve bonding force when laminated on an insulating substrate, a diffusion preventing treatment to prevent diffusion of copper ions, and prevents oxidation during storage, transportation, or lamination of copper foil and an insulating substrate. Antirust treatment, and the like. This will be described in detail below. This treatment process is performed in the processing machine which has an anode, and finally, a surface-treated copper foil is obtained through this process.

The electrolyte supplied between the positive electrode and the negative electrode is a copper sulfate solution, and the liquid composition is as follows based on 1 liter.

The copper concentration is 50 g to 110 g, preferably 60 g to 100 g, sulfuric acid concentration is 80 g to 200 g, preferably 90 g to 120 g, and the temperature of the electrolyte is 40 ° C to 80 ° C. The current density is 40 A / dm ² to 100 A / dm ² and preferably 50 A / dm ² to 85 A / dm ² . When the copper concentration is less than 50 g, the surface of the electrodeposited copper foil is rough and powder is formed, and the productivity is low. When the copper concentration exceeds 110 g, the electrolyte solution crystallizes and the workability is deteriorated. When the sulfuric acid concentration is less than 80 g, the electrolytic voltage rises, the production cost increases, and the temperature of the electrolyte rises, and the mechanical strength of the copper foil decreases. When the sulfuric acid concentration exceeds 200 g, the electrolytic voltage decreases, but the corrosiveness of the electrolytic solution becomes stronger, and the corrosion of the electrode for electrolytic copper foil is accelerated.

In this case, the electrolyte solution contains, as an additive, at least one organic compound selected from the group consisting of sulfur-containing compounds having a concentration of 0.5 to 40 mg, polyalkylene glycol-based surfactants having a concentration of 1 to 1000 mg, and low molecular weight gelatin. In addition, chlorine ions in the range of 0.1 mg to 80 mg are added.

More preferably, a nitrogen-containing compound may be used to increase the strength of the electrolytic copper foil produced by the electrolyte, and as the thiourea derivative, which is a nitrogen-containing compound, 0.1 mg of IM (2-imidazolidinethione) is used. 8 mg was used. Polyethylene-based, polypropylene-based, and polybutylene-based surfactants may be used as the polyalkylene glycol-based surfactants, and in particular, polyethylene ethylene glycol (Poly Ethylene Glycol) may be used. Can be used.

Sulfur containing compounds include disulfur compounds and dialkylamino-thioxomethyl-thioalkanesulfonic acids or salts thereof. The disulfur compound includes SPS (bis- (3-sulfopropyl) -disulfide, disodium salt), and dialkylamino-thioxomethyl-thio Examples of the alkanesulfonic acid or salts thereof include dithiocarbamic acid or salts thereof, and examples thereof include DPS (N, N-Dimethyldithiocarbamic acid (3-sulfopropyl) and sodium salt). The structural formula of the dialkylamino-thioxomethyl-thioalkanesulfonic acid or a salt thereof is shown in Chemical Formula 1, and the structural formula of DPS, which is one of the representative examples, is represented by Chemical Formula 2, and the structural formula of SPS is represented by Chemical Formula 3.

In Formula 1, R is an alkyl group (carbon atoms 1-6), n is 2-3 (ethane, propane), X means hydrogen or an alkali metal.

Of the above additives, the role of sulfur-containing compounds and surfactants is very important. This compound directly affects surface roughness and tensile strength. Sulfur-containing compounds generally act as grain refiners or brighteners that reduce the size of the grains and give a gloss to the surface compared to ordinary electrolytic copper foils to which glue or gelatin is added. The added surfactant acts as an electrodeposition inhibitor or carrier to lower the matte surface roughness of the electrolytic copper foil, thereby affecting electrodeposition. At this time, the surfactant transports the sulfur-containing compound, which is a brightening agent, to the cathode surface and is adsorbed on the protrusions of the electrode surface to inhibit the growth of the protrusions, thereby preventing growth. The sulfur-containing compound, which is a grain refiner, is fine on the electrodeposition surface. It acts first on the valleys to allow copper ions to reduce and grow there first, thereby controlling the roughness of the electrodeposition surface.

The thiourea derivative, which is a nitrogen-containing compound used in the present invention, acts to suppress crystal growth of copper at room temperature or high temperature due to vacancy in the electrodeposition layer, and suppresses the decrease in strength. Therefore, when the thiourea derivative, which is a nitrogen-containing compound, is added, it is possible to prevent the decrease in strength that occurs when not added. This can reduce defects that may occur when handling electrolytic copper foil or when manufacturing printed circuits. By controlling the amount of this additive, the strength can be changed to adjust the physical properties of the electrolytic copper foil according to the use.

In the case of an untreated copper foil, the electrolytic copper foil which concerns on this invention shows the roughness of the rough surface (matte surface) within 2.0 micrometers by R value. R _Z was measured according to the IPC ™ 650 2.2.17A method. For treatment after the copper foil subjected to the surface treatment under the roughness of the rough surface (a mat surface) it shows a range of 1.0 ~ 3.5 ㎛ the R _z value. The roughness value of the drum surface (glossy surface) of the copper foil in contact with the drum surface is not particularly limited because it has a roughness value according to the polishing of the drum surface.

The above untreated copper foil may be subjected to rough processing (also referred to as a Nodule treatment) to improve adhesion to an insulating substrate as necessary, a diffusion preventing treatment to prevent diffusion of copper ions, and an antirust treatment to prevent oxidation from the outside. And additional surface treatment processes. The surface treatment process results in a low profile copper foil for printed circuits, while the antirust treatment alone results in a secondary battery copper foil.

The roughening process is a two or three step process. In the first step, a fine powdery nucleus is formed, and the powdery phase has no binding force with the copper foil, and thus, in the second step, the powdery phase is combined with the copper foil. It is a process. The one-step treatment process is as follows. The copper concentration is 10 g to 40 g based on 1 liter of electrolyte, preferably 15 g to 25 g, sulfuric acid concentration 40 g to 150 g, preferably 60 g to 100 g, and the temperature of the electrolyte is 20 ° C. To 40 ° C. The current density is 20 A / dm ² to 100 A / dm ² and preferably 40 A / dm ² to 80 A / dm ² . The second stage is as follows. The copper concentration is 50 g to 110 g, preferably 55 g to 100 g, sulfuric acid concentration is 80 g to 200 g, preferably 90 g to 120 g, and the temperature of the electrolyte is 40 ° C to 80 ° C. The current density is 20 A / dm ² to 100 A / dm ² and preferably 40 A / dm ² to 80 A / dm ² . The diffusion prevention process is as follows. In order to prevent the diffusion of copper ions, a barrier layer is formed of various monometals such as zinc, nickel, iron, cobalt, molybdenum, tungsten, tin, indium, and chromium or two or three kinds of alloys.

Subsequently, antirust treatment is performed to prevent oxidation during storage, transportation or lamination of the copper foil and the insulating substrate. The rust treatment is chromated with chromic acid, sodium dichromate, potassium dichromate, chromic anhydride and the like. Subsequently, a treatment for increasing chemical bonding strength is performed.

In addition, a chemical adhesion improving process can be performed to compensate for the adhesion with the insulating substrate. Adhesion promoters usable for this purpose include silane coupling agents (RSiX ₃ ), silicon peroxides (R _4-n Si (OOR ') _n ), chromium-based adhesion promoters (((RCO ₂ H ₃ OHCrOHCrHOH ₂ ) ₂ OH), organic Titanium-based adhesion promoters ((C ₄ H ₉ CHC ₂ H ₅ CH ₂ O) ₄ Ti), organophosphate adhesion promoters (RO ₂ P (OH) ₂ ) and the like.

Example

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples. The symbol g / L used here means the content of the substance based on 1 liter of electrolyte.

For the pulverization process, an electrolyte having a liquid composition as shown in Table 1 is prepared. Copper concentration of the said electrolyte solution is 80 g / L, sulfuric acid concentration is 90 g / L, and temperature of electrolyte solution is 45 degreeC. Additives as shown in the following Table 1 were added. The current density was electrodeposited at 60 A / dm ² and the chlorine ions were maintained at 25 mg / L.

In the case of Example 1, 6 mg / L of N-dimethyldihiocarbamic acid (3-sulfopropyl) ester, sodium salt (DPS) was used as the sulfur-containing compound, and Poly Ethylene Glycol (PEG) 1 was used as the polyalkylene glycol-based surfactant. mg / L was used.

In the case of Example 2, 1 mg / L of SPS (Bis- (3-sulfopropyl) -disulfide, disodium salt) was used as the sulfur-containing compound, and 30 mg of poly propylene glycol (PPG) as a polyalkylene glycol-based surfactant. / L was used.

In the case of Example 3, 30 mg / L of N-dimethyldihiocarbamicacid (3-sulfopropyl) ester, sodium salt (DPS) as a sulfur-containing compound, and 30 mg / L of PEG (Poly Ethylene Glycol) as a polyalkylene glycol-based surfactant were added It was.

In the case of Example 4, 5 mg / L of Bis- (3-sulfopropyl) -disulfide, disodium salt (SPS) as a sulfur-containing compound, and 1 mg / L of PEG (Poly Ethylene Glycol) as a polyalkylene glycol-based surfactant were added It was.

In the case of Example 5, 3 mg / L of N-dimethyldihiocarbamic acid (3-sulfopropyl) ester, sodium salt (DPS) as a sulfur-containing compound, 800 mg / L of polypropylene glycol glycol (PPG) as a polyethylene glycol-based surfactant, molecular weight 5 mg / L of low molecular weight gelatin up to 6000 was added.

In the case of Example 6, SPS (Bis- (3-sulfopropyl) -disulfide, disodium salt) 5 mg / L as a sulfur-containing compound, 0.5 mg / L of IM (2-imidazolidinethione) IM, which is a thiourea derivative, which is a nitrogen-containing compound, 25 mg / L of polyethylene ethylene glycol (PEG) was added as a glycol-based surfactant.

In the case of Example 7, 3 mg / L of Bis- (3-sulfopropyl) -disulfide, disodium salt (SPS) and 5 mg / L of N-Dimethyldihiocarbamic acid (3-sulfopropyl) ester, sodium salt) as sulfur-containing compounds As a polyethylene glycol surfactant, 30 mg / L of PEG (Poly ethylene glycol) and PPG (Poly Propylene Glycol) were mixed and added.

Untreated copper foils corresponding to Examples 1 to 7 were obtained under electrolysis conditions as shown in Table 1, using a titanium anode coated with an electrolyte solution prepared above, and a rotating cylindrical titanium anode.

In the case of sulfur-containing compounds, the surface roughness of the rough surface was increased in the range exceeding 40 mg / L, and the Rz value tended to exceed 2.0 um. The problem is that the illuminance increases and the elongation also decreases. In the case of the polyalkylene glycol-based surfactant, the surface roughness of the rough surface was reduced in the range of 1 mg / L to 1000 mg / L, and particularly preferably in the range of 1 mg / L to 300 mg / L. Although the desired surface roughness was obtained at, the adjustment required to make the use current density a little higher or lower depending on the dosage. In the case of sulfur-containing compounds and polyalkylene glycol-based surfactants, when the concentration is higher than the upper limit, the surface becomes rough and a burning phenomenon occurs (the electrodeposition to powder), which makes it difficult to use satisfactory electrolytic copper foil. .

In the case of the nitrogen-containing compound incidentally included in the electrolyte composition in order to control the hardness of the electrolytic copper foil to be produced, the range of 0.1 mg / L to 8 mg / L was suitable. If the amount is too small, the strength improvement is insignificant. If the amount is too high, the strength is high, but the surface roughness is increased and the elongation is low.

For each of the untreated copper foils, the surface roughness Rz was measured according to the IPC ™ 650 2.2.17A method, and the elongation and tensile strength of the copper foils were measured at room temperature (25 ° C) and 180 ° C according to the IPCTM 650 standard treatment method. It was. The results are shown in Table 2.

Next, the surface treatment process was performed about the untreated copper foil which concerns on the said Example 1 thru | or Example 7. First, sodium cyanide 110 g / L, sodium hydroxide 60 g / L, cyanide copper 90 g / L, zinc cyanide 5.3 g / L, pH 11.0 to 11.5, temperature 50 ° C., current density 5 A / dm²Electrodeposited for 10 seconds. As antirust treatment, sodium dichromate 10 g / L, temperature 25 ℃, pH 4.5, current density 0.5 A / dm²It was carried out for 2 seconds.

Comparative example

The electrolyte composition and the chlorine ion concentration are the same as in the above embodiments. In the case of the comparative example 1, 2 mg / L of low molecular weight gelatin with a molecular weight of 6000 or less was added as an additive. In the case of Comparative Example 2, 1 mg / L of TU (thiourea) was added together with 2 mg / L of low molecular weight gelatin having a molecular weight of 6000 or less. In Comparative Example 3, SPS and PEG were added by 50 mg / L and 30 mg / L, respectively, and in Comparative Example 4, DPS and PPG were added by 3 mg / L and 1500 mg / L, respectively.

Untreated copper foils corresponding to Comparative Examples 1 to 4 were obtained under electrolysis conditions as shown in Table 1, and surface roughness Rz and Rmax, elongation at room temperature (25 ° C), and elongation and tensile strength at 180 ° C were respectively obtained for these. It was measured according to the method of IM 650 2.4.18A, and the results are shown in Table 2. Next, the surface treatment process was performed about the untreated copper foil which concerns on the comparative example 1 thru | or the comparative example 4.

Table 2 is a result of comparing the physical properties of the copper foil prepared in the test of the Example and Comparative Example under the conditions shown in Table 1.

As shown in Table 2, according to the embodiment of the present invention, roughness (Rz) of the rough surface is adjusted to 2.0 or less by the sulfur-containing compound, so that the roughness (Rz) of the drum surface can be maintained similarly, and nitrogen-containing By controlling the amount of the thiourea derivative which is a compound, the strength change was made, and the production of the electrolytic copper foil according to the use was attained.

additive Liquid composition SPS (mg / L) DPS (mg / L) IM (mg / L) PEG (mg / L) PPG (mg / L) Low Molecular Gelatin (mg / L) TU (mg / L) Cl ^- (mg / L) Copper (g / L: ion) Sulfuric acid (g / L) Example 1 - 6 - One - - - 25 80 90 Example 2 One - - 30 - - - Example 3 - 30 - 30 - - - Example 4 5 - - One - - - Example 5 - 3 - - 800 5 - Example 6 5 - 0.5 25 - - - Example 7 3 5 - 30 30 - - Comparative Example 1 - - - - - 2 - Comparative Example 2 - - - - - 2 One Comparative Example 3 50 - - 30 - - - Comparative Example 4 - 3 - - 1500 - -

Current density: 60 A / dm ² , liquid temperature: 45 ℃

DPS: N-Dimethyldithiocarbamic acid (3-sulfopropyl) ester, sodium salt

SPS: Bis- (3-sulfopropyl) -disulfide, disodium salt

IM: 2-imidazolidinethione

PEG: Poly Ethylene Glycol

PPG: Poly Propylene Glycol

Low Molecular Gelatin: Gelatin up to molecular weight 6000 or less

TU; thiourea

Rough Surface Roughness Drum surface roughness Tensile Strength (room temperature) Elongation (room temperature) Tensile Strength (180 ° C) Elongation (180 ° C) (R _z : μm) (R _z : μm) (kgf / ㎡) (%) (kgf / ㎡) (%) Example 1 1.52 1.68 33.2 8.9 22.5 7.6 Example 2 1.83 1.76 29.5 9.6 20.9 8.0 Example 3 1.42 1.84 33.4 12.9 22.2 14.4 Example 4 1.88 1.91 30.4 12.9 20.6 10.6 Example 5 1.81 1.79 31.4 4.1 18.4 3.1 Example 6 0.50 1.75 33.2 11.4 23.6 6.0 Example 7 1.14 1.55 32.0 8.8 20.6 4.2 Comparative Example 1 3.53 1.81 37.1 5.6 22.8 2.2 Comparative Example 2 1.9 1.85 49.0 1.5 22.0 1.9 Comparative Example 3 2.23 1.88 34.2 1.9 22.2 3.5 Comparative Example 4 2.38 1.79 13.9 0.23 16.9 1.2

In the case of the electrolytic copper foil prepared in Examples according to the present invention as shown in Examples 1 to 7 shown in Table 2, the surface roughness R _z value of the rough surface has a range within 2.0 μm in the state of milling, It can be seen that the tensile strength does not change rapidly even at high temperature of 180 ℃.

In the case of an untreated copper foil, the electrolytic copper foil which concerns on this invention shows the roughness of the rough surface (matte surface) in the range of 2.0 micrometers or less by Rz value. In the case of the processed copper foil after following surface treatment, the roughness of a rough surface (matte surface) shows a range of 1.0-3.5 micrometers by Rz value. Therefore, the electrolytic copper foil which concerns on this invention has the roughness of the rough surface relatively low, and the roughness of both surfaces of an electrolytic copper foil has a similar level.

In the case of the electrolytic copper foil manufactured according to the prior art, there is a problem that the strength decreases rapidly at a high temperature (180 ° C.) even when maintaining a good strength at room temperature, but the electrolytic copper foil according to the present invention does not suddenly change even at high temperatures. . Therefore, the electrolytic copper foil which concerns on this invention is suitable for a fine and highly integrated PCB circuit.

Moreover, even when used as a collector for secondary batteries, since the roughness of both surfaces of an electrolytic copper foil has a similar level, reliable battery characteristics can be obtained. Since the electrolytic copper foil according to the present invention has the property of preventing rapid drop in tensile strength due to the temperature rise and excellent elongation property even at room temperature and high temperature, the electrolytic copper foil does not bend or warp in the subsequent treatment process and thus does not cause a short circuit of the printed circuit. It is suitable for use as a circuit board or as a secondary battery current collector.

It should be understood that various modifications to the embodiments of the invention described herein may be employed in implementing the invention. Accordingly, the following claims are intended to define the scope of the invention, and methods and configurations and equivalents thereof within these claims are intended to be encompassed by the claims.

Claims (10)

In the electrolytic solution containing at least one selected from sulfuric acid and copper sulfate used when producing the electrolytic copper foil by electrolysis, based on 1 liter of the electrolyte, 0.5 to 40 mg of at least one sulfur containing compound selected from disulfur compounds, dialkylamino-thioxomethyl-thioalkanesulfonic acids and dialkylamino-thioxomethyl-thioalkanesulfone salts; 1 to 1000 mg of at least one organic compound selected from the group consisting of polyalkylene glycol-based surfactants and low molecular weight gelatins; And Electrolyte for producing electrolytic copper foil, characterized by the addition of 0.1 to 80 mg of chlorine ion. The method of claim 1, The dialkylamino-thioxomethyl-thioalkanesulfonic acid or its salt is dithiocarbamic acid or its salt, The electrolyte solution for electrolytic copper foil manufacture. The method of claim 1, The electrolyte solution for producing an electrolytic copper foil, wherein the electrolyte solution additive further comprises 0.1 to 8 mg / L of a thiourea derivative which is a nitrogen-containing compound. The method of claim 1, The disulfide compound is SPS (bis- (3-sulfopropyl) -disulfide disodium salt (Bis- (3-sulfopropyl) -disulfide, disodium salt), the electrolyte solution for producing an electrolytic copper foil. The method of claim 1, Electrolytic solution for producing an electrolytic copper foil, wherein the organic compound is a polyalkylene glycol-based surfactant. delete In the manufacturing method of the electrolytic copper foil, A) 0.5 to 40 mg of at least one sulfur-containing compound selected from the disulfur compound, the dialkylamino-thioxomethyl-thioalkanesulfonic acid and the dialkylamino-thioxomethyl-thioalkanesulfone salt based on 1 liter of the electrolyte; Preparing an electrolyte solution to which 1 to 1000 mg of at least one organic compound selected from the group consisting of polyalkylene glycol-based surfactants and low molecular gelatin and 0.1 to 80 mg of chlorine ions are added; And B) A method for producing an electrolytic copper foil, comprising the step of generating an electrolytic copper foil on the cathode by impregnating the positive electrode and the negative electrode with the electrolyte and then flowing electricity. The method of claim 7, wherein The dialkylamino-thioxomethyl-thioalkanesulfonic acid is dithiocarbamic acid, and the dialkylamino-thioxomethyl-thioalkanesulfone salt is a dithiocarbamic salt. The method of claim 7, wherein A method for producing an electrolytic copper foil, wherein the electrolyte solution further comprises 0.1 to 8 mg / L of a thiourea derivative which is a nitrogen-containing compound. The method of claim 7, wherein The said disulfur compound is SPS (bis- (3-sulfopropyl) -disulfide disodium salt (Bis- (3-sulfopropyl) -disulfide, disodium salt) The manufacturing method of the electrolytic copper foil characterized by the above-mentioned.