TW201631223A - Electrolytic copper foil, electric component and battery comprising the foil - Google Patents

Abstract

The present invention relates to the electrolytic copper foil, electric component and battery comprising the foil. The present invention provides an electrolytic copper foil, wherein the average diameter of the pore of the inter-region used as the surface element protruded from the precipitating surface is from 1 nm to 100 nm. The mentioned electrolytic copper foil presents high elongation rate along with keeping low roughness and high strength, thereby being able to be used in the semiconductor packaging substrate for TAB (Tape Automated Bonding) used in the middle/large lithium ion secondary battery and the current collector and TCP (Tape Carrier Package).

Description

Electrolytic copper foil, electrical component and battery including the same

The present invention relates to an electrolytic copper foil, an electrical component including the electrolytic copper foil, and a battery, and more particularly to a low-roughness, high-strength, and high-stretch electrolytic copper foil which has high tensile strength and elongation after high-temperature heat treatment.

As the current collector of the secondary battery, a copper foil is generally used. The above copper foil mainly uses a rolled copper foil which is subjected to rolling processing, but it is expensive to manufacture and it is difficult to manufacture a wide copper foil. Further, the rolled copper foil needs to use a lubricating oil during the rolling process, and contamination of the lubricating oil causes a decrease in adhesion to the active material, which may lower the charge and discharge loop characteristics of the battery.

Lithium batteries are accompanied by heat generation based on volume change and overcharge during charge and discharge. Further, in order to improve the adhesion to the electrode active material, the copper foil substrate is less affected by the expansion and contraction of the active material layer based on the charge and discharge loop to prevent the copper foil from being used as the current collector. The effect of wrinkles, cracks, and the like is generated, and the surface roughness of the copper foil is low. Therefore, it has been urgent to develop a high-strength, high-strength, and low-roughness copper foil which can withstand the volume change and heat generation of a lithium battery and is excellent in adhesion to an active material.

In order to meet the demand for the thinness and the small size of electronic devices, the need for fine wiring of semiconductor mounting boards or motherboard substrates has gradually increased in order to increase the integration of circuits in a small area based on high functionality, miniaturization, and weight reduction. increase. When a thick copper foil is used in the manufacture of a printed circuit board having such a fine pattern, the etching time for forming the wiring circuit becomes long, and the sidewall perpendicularity of the wiring pattern is lowered. In particular, in the case where the wiring line width of the wiring pattern formed by etching is narrow, the wiring may be broken. Therefore, in order to obtain a fine pitch circuit, it is necessary to provide a copper foil having a thinner thickness. However, since the thickness of the copper foil is limited by the thickness of the copper foil, the mechanical strength is weak, and when the printed circuit board is manufactured, the frequency of defects such as wrinkles or bending increases.

Further, a Hall element located at the center of the product in a semiconductor package substrate for TAB (Tape Automated Bonding) used in TCP (Tape Carrier Package) ( The inner lead provided on the device hall will directly engage the plurality of terminals of the IC chip. At this time, the current is instantaneously turned on by the bonding device to heat and apply a certain pressure. Thereby, the inner lead formed by the etching of the electrolytic copper foil is stretched by the joining pressure to be elongated.

Therefore, it is required to provide a low-roughness copper foil which is thin in thickness, high in mechanical strength, and capable of achieving high elongation.

One aspect of the invention provides a new electrolytic copper foil.

Another aspect of the invention provides an electrical component comprising an electrolytic copper foil.

Yet another aspect of the present invention is to provide a battery comprising an electrolytic copper foil.

In order to achieve the object as described above, an electrolytic copper foil according to an aspect of the invention, wherein a pore of a region between the convex surface elements as a deposition surface has an average diameter of 1 nm to 100 nm.

The cross-sectional area of the pores may be 10% to 50% with respect to the area of the precipitation surface, and the pores may be 100 / μm ² to 1000 / μm ² .

The ratio of the average density of the pores in the precipitation surface to the average density of the convex surface elements in the precipitation surface may be 10% to 50%.

The gloss Gs (60°) with respect to the width direction of the deposition surface may be 500 or more.

The tensile strength of the electrolytic copper foil before heat treatment may be 40 kgf/mm ² to 70 kgf/mm ² , and the tensile strength after heat treatment may be 40 kgf/mm ² to 70 kgf/mm ² . The heat treatment can be performed at 180 ° C for 1 hour. Further, the tensile strength after the heat treatment is preferably from 85% to 99% of the tensile strength before the heat treatment.

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

The corner curl angle of the electrolytic copper foil may be 0 to 45, the corner curl height may be 0 mm to 40 mm, and the thickness of the electrolytic copper foil may be 2 μm to 10 μm.

According to another aspect of the present invention, a battery comprising the electrolytic copper foil as described above is provided.

According to still another aspect of the present invention, an electrical component is provided, comprising: an insulating substrate; and the electrolytic copper foil attached to a surface of the insulating substrate.

The size and density of the pores between the surface elements which protrude toward the outside on the deposition surface of the electrodeposited copper foil of the present invention are relatively small, and also exhibit high gloss before the post-treatment process, thereby having an effect of improving product quality. Further, the electrodeposited copper foil of the present invention exhibits high elongation while exhibiting high strength, and the pressure inside the electrodeposited copper foil is small to prevent the corner curl phenomenon. Thus, the electrolytic copper foil of the present invention exhibits low roughness, high strength, and high elongation, thereby facilitating the execution of the process and reducing the defect rate of the product, and is used in products such as a cathode of a PCB or a secondary battery. In this case, product reliability can be improved.

1 is a 2000-fold field emission scanning electron microscopy (FESEM) image of an electrolytic copper foil according to an embodiment of the present invention.

2 is a 10000-fold FESEM image of an electrolytic copper foil according to an embodiment of the present invention.

Fig. 3 is a 50,000-times FESEM image of an electrolytic copper foil according to an embodiment of the present invention.

4 is a 100,000-fold FESEM image of an electrolytic copper foil according to an embodiment of the present invention.

Fig. 5 is a 100,000-fold FESEM image of an electrolytic copper foil according to an embodiment of the present invention.

Fig. 6 is an XRD (X-ray diffraction) spectrum of a deposition surface of the electrolytic copper foil produced in Example 1.

Fig. 7 is a scanning electron microscopy (SEM) image of the surface of the electrodeposited copper foil produced in Example 1.

8 is an SEM image of the surface of the electrodeposited copper foil of Example 2.

9 is an SEM image of the surface of the electrodeposited copper foil of Example 3.

Fig. 10 is an SEM image of the surface of the electrodeposited copper foil of Example 4.

Fig. 11 is an SEM image of the surface of the electrodeposited copper foil of Comparative Example 1.

Fig. 12 is an SEM image of the surface of the electrodeposited copper foil of Comparative Example 2.

Fig. 13 is an SEM image of the surface of the electrodeposited copper foil of Comparative Example 3.

Fig. 14 is an SEM image of the surface of the electrodeposited copper foil of Comparative Example 4.

Hereinafter, the electrodeposited copper foil of the present invention, the electrical component and the battery including the above-described electrodeposited copper foil, and the method for producing the electrodeposited copper foil will be described in more detail.

In the electrodeposited copper foil according to an embodiment of the present invention, the pores of the region between the convex surface elements as the precipitation surface have an average diameter of 1 nm to 100 nm. In the electrodeposited copper foil of the present embodiment, the dark portion shown as the deposition surface, that is, the average diameter of the pores which are present in the dark portion between the two surface elements is small in units of nm. In the present specification, the "surface element" is a bright portion shown on the deposition surface, which indicates a convex portion on the surface of the electrolytic copper foil; the "pore" is a surface which is formed on the surface of the electrolytic copper foil and protrudes upward. A portion introduced between elements and introduced internally, which represents a portion that is darker.

In the electrodeposited copper foil of the present invention, the gloss (Gs (60°)) in the width direction of the deposition surface may be 500 or more. That is, the gloss of the deposition surface of the electrolytic copper foil is high. The electrolytic copper foil is obtained by supplying a current between the cathode drum and the anode which are immersed and rotated in the copper electrolyte bath to deposit a copper foil on the surface of the cathode drum, and the surface of the electrolytic copper foil which is in contact with the cathode drum is a glossy surface. (Shiny side, S surface), the opposite side is the precipitation surface. The precipitation surface is different from the glossy surface in contact with the drum, and it is a surface on which the copper foil is directly deposited, so that in principle, the gloss is small and the surface roughness is high. Therefore, the precipitation surface is reduced in surface roughness by post-treatment, and the treatment for imparting gloss is performed as needed.

However, the deposited surface of the electrodeposited copper foil of the present invention has a high glossiness. 1 is a 2000-fold field emission scanning electron microscopy (FESEM) image of an electrolytic copper foil according to an embodiment of the present invention.

The precipitation surface is in the process characteristics, generally when 2000 times FESEM analysis is performed. The surface will have irregularities and the gloss is not high. On the other hand, the deposition surface of the electrolytic copper foil of the present invention of Fig. 1 exhibits a gloss like a mirror similar to the glossy surface.

By increasing the resolution of FESEM analysis, 10000 times FESEM for Figure 2 The image, the 50,000-times FESEM image of FIG. 3, and the 100,000-fold FESEM image of FIG. 4 were analyzed, and as the resolution was increased, irregularities appeared on the surface. However, it was difficult to confirm the unevenness in the 10000-fold FESEM image, and the unevenness was confirmed at an ultra-high resolution such as 50,000 times FESEM and 100,000-fold FESEM analysis.

In the 100000-fold FESEM image of Figure 4, it appears as a slave copper foil. The pores of the region between the surface features that protrude from the surface. In the electrodeposited copper foil of the present invention of Fig. 4, the size and height of the surface elements on the deposition surface are uniform, the diameter of the pores is small, and the size of the pores is relatively uniform. The results of tilting 52 degrees of the same sample and performing 100,000-fold FESEM analysis are shown in FIG. In Figure 5, the voids between the raised surface features are more pronounced.

In the case where the surface has the same surface roughness, if the pore size is small Or a small number, the surface gloss will increase. For example, in the case where the volume of the pores on the deposition surface is the same, if the depth of the pores is shallow and the average diameter is large, the pores which are darker regions appearing on the surface may affect the gloss more. That is, in the case where the volumes of the pores are the same, if the depth of the pores is deep and the average diameter is small, the gloss can be improved.

Therefore, in terms of gloss, the pores on the deposition surface of the electrolytic copper foil of the present invention It is preferably deep and has a small average diameter. In view of the fact that the Rz of the surface roughness on the precipitation surface is 1.4 μm or less, the average diameter of the pores is from 1 nm to 100 nm, which means that the depth of the pores is deep so that the dark portions of the pores are not exposed to the deposition surface.

Also, the pores may exhibit a cross-sectional area of 10% to 50% with respect to the entire area of the deposition surface. This means that the entire area of the pores with respect to the deposition surface preferably exhibits an area of 50% or less. Meanwhile, the ratio of the average density of the pores on the precipitation surface to the average density of the convex surface elements on the precipitation surface may be 10% to 50%. In terms of gloss, it is preferred that the pores be present in a smaller number than the surface elements that protrude toward the outside. Also, the pores may be from 100 / μm ² to 1000 / μm ² .

The cross-sectional area of the pores can be calculated from the image of Figure 3 or Figure 4 by dividing the entire area of the darker region by the number of pores.

In the electrodeposited copper foil according to the exemplary embodiment, the surface roughness Rz of the precipitation surface is 1.4 μm or less, and the tensile strength after heat treatment is 40 kgf/mm ² or more, and the elongation is 4% or more.

The electrodeposited copper foil is a low-roughness copper foil having a surface roughness Rz of 1.4 μm or less, and has a high tensile strength of 40 kgf/mm ² or more, and thus has high mechanical strength. At the same time, the above-mentioned electrodeposited copper foil will have a high elongation of 4% or more after passing through a high temperature.

Further, the electrodeposited copper foil of the present invention has a corner curl angle of from 0 to 45 . The corner curl angle refers to an angle at which the end portion of the electrodeposited copper foil, that is, the corner or the edge is bent, in the case where the electrolytic copper foil is placed on a flat floor. The corner curling phenomenon of the electrolytic copper foil occurs when the internal energy of the electrolytic copper foil is uneven. When corner curling occurs, the corners are torn in a process such as lamination in a PCB process, which causes more defects. In the lithium secondary battery process, problems such as tearing or folding or wrinkling of the corners may occur when the active material is coated. If the corner angle of the electrolytic copper foil is large and it is difficult to use in a subsequent process, the corner curl angle is preferably from 0 to 45. Further, the electrolytic copper foil is developed on a flat floor and cut into an X shape, and the height at which the cut portion is lifted is referred to as a corner curl height, and the corner curl height is preferably 0 mm to 40 mm. In the case of the electrolytic copper foil of the present invention, since the copper crystal memory has high strength in the presence of impurities, the degree of curling of the corners is expected to be large, and impurities are not present in the copper grain boundaries, so that the internal pressure thereof is lowered, thereby Reduce the degree of curling of the corners.

Therefore, the above-mentioned electrolytic copper foil can be used at the same time as a PCB (Printed Circuit Board) / FPC (Flexible Printed Circuit) use and a collector of a battery.

When the surface roughness Rz of the precipitation surface in the above-mentioned electrodeposited copper foil is more than 1.4 μm, the contact surface of the surface of the electrodeposited copper foil for the cathode current collector with the active material becomes small, so that the life and initiality of the charge and discharge loop may be made possible. The charged capacity is reduced. Further, when the surface roughness Rz of the deposition surface is larger than 1.4 μm, it is difficult to form a high-density circuit having a fine pitch on the printed circuit board.

The above-mentioned electrolytic copper foil has a tensile strength of 40 kgf/mm ² to 70 kgf/mm ² and thus has high strength characteristics. Further, after the heat treatment, the electrolytic copper foil has a tensile strength of 40 kgf/mm ² to 70 kgf/mm ² . The heat treatment can be performed, for example, at 150 ° C to 220 ° C, and in detail, can be performed at 180 ° C. The heat treatment can be carried out for 30 minutes, 1 hour, 2 hours, and several hours, but it takes more than 1 hour to maintain a certain tensile strength. The heat treatment is for determining the tensile strength of the electrolytic copper foil, which is a treatment for obtaining tensile strength or elongation at a constant level in the case where the electrolytic copper foil is stored or placed in a subsequent process. .

When the above-mentioned electrolytic copper foil is subjected to heat treatment, if its tensile strength is less than 40 kgf/mm ² , the mechanical strength is weak and it is difficult to use.

Preferably, the tensile strength after heat treatment of the above-mentioned electrolytic copper foil is similar to the tensile strength before heat treatment. The tensile strength after heat treatment of the above-mentioned electrolytic copper foil is preferably 85% to 99% of the tensile strength before heat treatment, and if the strength can be maintained even after the heat treatment, it is easy to handle and improve the yield in the subsequent process.

The elongation of the above-mentioned electrolytic copper foil before heat treatment may be 2% to 15%. Further, 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 from 1 to 4.5 times the elongation before heat treatment.

If the above electrolytic copper foil has an elongation after heat treatment of less than 4%, cracks may occur in the case where the subsequent process is a high temperature process. For example, in the case where the above-mentioned electrolytic copper foil is used as a cathode current collector of a secondary battery, since the process of manufacturing the cathode current collector is a high-temperature process, and the charge and discharge are accompanied by a volume change of the active material layer, it may be Cracks occur and defects are induced, so it is necessary to maintain a predetermined elongation after heat treatment.

In the XRD spectrum of the electrodeposited copper foil on the deposition surface, the intensity I (200) as a diffraction peak of the (200) crystal plane and the intensity I (111) of the diffraction peak of the (111) crystal plane The ratio I(200) / I(111) may be from 0.5 to 1.0.

For example, as shown in FIG. 6, in the XRD spectrum for the precipitation surface, a diffraction peak for the (111) crystal plane is exhibited at a diffraction angle (2θ) of 43.0 ° ± 1.0 ° at a diffraction angle (2θ) of 50.5 ° ± The diffraction peaks for the (200) crystal faces are exhibited at 1.0 °, and their intensity ratio I (200) / I (111) may be 0.5 to 1.0 or more.

For example, in the above electrolytic copper foil, I(200) / I(111) may be from 0.5 to 0.8. in In the XRD spectrum of the above-mentioned precipitated surface of the above-mentioned electrodeposited copper foil, the ratio of the orientation coefficient obtained from the orientation coefficient M (200) for the (200) crystal plane and the orientation coefficient M (111) for the (111) crystal plane M (200) / M (111) can be 1.1 to 1.5. The orientation index is a value obtained by dividing the relative peak intensity of a specific crystal face of an arbitrary sample by the relative peak intensity of the characteristic crystal face obtained from a standard sample having no orientation for all the crystal faces. For example, in the above electrolytic copper foil, M (200) / M (111) may be 1.2 to 1.4.

After the above-mentioned electrolytic copper foil is heat-treated at 180 ° C for 1 hour, its elongation can be Thought it is 10% or more. That is, the above-mentioned electrolytic copper foil may have a high elongation of elongation of 10% or more after high-temperature heat treatment. For example, the above-mentioned electrolytic copper foil may have an elongation of 10% to 20% after high-temperature heat treatment. For example, the above-mentioned electrolytic copper foil may have an elongation of 10% to 15% after high-temperature heat treatment. For example, the above-mentioned electrolytic copper foil may have an elongation of 10% to 13% after high-temperature heat treatment. The above electrolytic copper foil may have an elongation of 2% or more before heat treatment. For example, the above electrolytic copper foil may have an elongation of 2% to 20% before heat treatment. For example, the above-mentioned electrolytic copper foil may have an elongation of 5% to 20% before heat treatment. For example, the above-mentioned electrolytic copper foil may have an elongation of 5% to 15% before heat treatment. For example, the above-mentioned electrolytic copper foil may have an elongation of 5% to 10% before heat treatment. The above phrase "before heat treatment" means 25 ° C to 130 ° C which is a temperature before heat treatment in a high temperature state. The elongation is a value obtained by dividing the distance extended before the electrolytic copper foil is broken by the initial length of the electrolytic copper foil.

The surface roughness Rz of the deposition surface of the above-mentioned electrodeposited copper foil may be 0.7 μm or less. The above-mentioned electrodeposited copper foil has a low roughness of Rz of 0.7 μm or less, and can be used as a copper foil for a PCB/FPC and a copper foil for a cathode current collector of a secondary battery. For example, the surface roughness Rz of the deposition surface of the above-mentioned electrodeposited copper foil may be 0.5 μm or less. For example, the surface roughness Rz of the deposition surface of the above-mentioned electrolytic copper foil may be 0.45 μm or less.

The surface roughness Ra of the precipitation surface of the above-mentioned electrolytic copper foil may be 0.15 μm. under. The above-mentioned electrodeposited copper foil has a low roughness of Ra of 0.15 μm or less, and can be used as a copper foil for a PCB/FPC and a copper foil for a cathode current collector of a secondary battery. For example, the surface roughness Ra of the deposition surface of the above-mentioned electrodeposited copper foil may be 0.12 μm or less. For example, the above electrolysis The surface roughness Ra of the precipitation surface of the copper foil may be 0.11 μm or less.

The tensile strength after heat treatment of the above-mentioned electrolytic copper foil 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 above heat treatment is the tensile strength of the copper foil which is obtained without high-temperature heat treatment. The above-mentioned electrolytic copper foil may have a tensile strength before heat treatment of 40 kgf/mm ² to 70 kgf/mm ² .

In the above-mentioned electrolytic copper foil, the gloss in the width direction of the deposition surface (Gs (60°)) may be 500 or more. For example, in the above-mentioned electrolytic copper foil, the gloss (Gs (60°)) in the width direction of the deposition surface may be 500 to 1,000. The above glossiness is a value measured in accordance with JIS Z 871-1997.

The thickness of the above-mentioned electrolytic copper foil may be 35 μm or less. For example, the above electrolytic copper foil may have a thickness of 6 to 35 μm. For example, the above electrolytic copper foil may have a thickness of 6 to 18 μm. Further, for example, the above-mentioned electrolytic copper foil may have a thickness of 2 to 10 μm.

When the electrodeposited copper foil needs to be bonded to an insulating resin or the like, the surface treatment can be further performed in order to achieve a practical level of adhesion or the like. The surface treatment on the copper foil may, for example, be one of heat resistance and chemical resistance treatment, chromate treatment, decane coupling agent treatment, or a combination thereof, and how the surface treatment is carried out, the technique to which the present invention pertains One of ordinary skill in the art can select and perform according to the resin or process conditions utilized as the insulating resin.

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

The electrical component is, for example, a TAB tape, a printed circuit board (PCB), a flexible printed circuit board (FPC), or the like, but is not limited thereto, and the electrolytic copper foil is attached to an insulating substrate. It can be used in the art.

A battery according to an exemplary embodiment includes the above-described electrolytic copper foil. The above-mentioned electrodeposited copper foil can be used as a cathode current collector of the above battery, but is not limited thereto, and it can also be used as another component used in a battery. The above battery is not particularly limited and includes All of the primary battery and the secondary battery may be any battery that can be used in the art as long as it is a battery using an electrolytic copper foil as a current collector such as a lithium ion battery, a lithium polymer battery, or a lithium air battery.

An electrolytic copper foil manufacturing method according to an exemplary embodiment, comprising: a package a step of electrolyzing a copper electrolytic solution containing the additive A, the additive B, the additive C, and the additive D, wherein the additive A is one or more selected from the group consisting of a thiourea-based compound and a nitrogen-containing heterocyclic ring to which a thiol group is bonded. The additive B is a sulfonic acid or a metal salt of a compound containing a sulfur atom, the additive C is a nonionic water-soluble polymer, and the additive D is a phenazinium-based compound.

The above-described method for producing an electrolytic copper foil can produce a low-roughness copper foil having a small thickness, high mechanical strength, and high elongation by an additive containing a new component. The above copper electrolyte may contain chlorine (chloride ion) at a concentration of 1 to 40 ppm. If a small amount of chloride ions are present in the copper electrolyte, the initial nucleation site increases and the crystal grains become fine during electrolytic gold plating, and the precipitate of CuCl ₂ formed on the grain boundary interface is heated at a high temperature. The crystal growth is suppressed, so that the thermal stability at high temperatures can be improved. When the concentration of the chloride ion is less than 1 ppm, the concentration of the chlorine ion required in the copper sulfonate-sulfonic acid electrolyte is insufficient, the tensile strength before the heat treatment is lowered, and the thermal stability at a high temperature is lowered. When the concentration of the chlorine ions is more than 40 ppm, the surface roughness of the precipitation surface may increase, and it may be difficult to produce an electrolytic copper foil having a low roughness, which lowers the tensile strength before the heat treatment and lowers the thermal stability at a high temperature.

In the above copper electrolyte, the content of the above additive A may be 1 to 10 ppm. The content of the above additive B may be 10 to 200 ppm, the content of the above additive C may be 5 to 40 ppm, and the content of the above additive D may be 1 to 10 ppm.

In the above copper electrolyte, the additive A can improve the stability of the electrolytic copper foil. And improve the strength of electrolytic copper foil. When the content of the above additive A is less than 1 ppm, the tensile strength of the electrolytic copper foil may be lowered. When the content of the above additive A is more than 10 ppm, the surface roughness of the precipitation surface is increased, so that it may be difficult to produce a low-roughness electrolytic copper. Foil and reduce tensile strength.

In the above copper electrolyte, the additive B can increase the surface gloss of the electrolytic copper foil. When the content of the above additive B is less than 10 ppm, the gloss of the electrolytic copper foil may be lowered. When the content of the above additive B is more than 200 ppm, the surface roughness of the precipitation surface is increased, so that it may be difficult to produce a low-roughness electrolytic copper foil. The tensile strength of the electrolytic copper foil is lowered.

In the above copper electrolyte, the additive C can reduce the surface roughness of the electrolytic copper foil And improve the surface gloss. When the content of the above-mentioned additive C is less than 5 ppm, the surface roughness of the precipitation surface rises, so that it may be difficult to manufacture a low-roughness electrolytic copper foil, and the gloss of the electrolytic copper foil is lowered, when the content of the above-mentioned additive C is more than 40 ppm. It is possible that there is no difference in physical properties or appearance of the electrolytic copper foil and it is not economical.

In the above copper electrolyte, the additive D can be used to increase the surface of the electrolytic copper foil. The role of flatness. When the content of the above-mentioned additive D is less than 1 ppm, the surface roughness of the precipitation surface rises, so that it may be difficult to manufacture a low-roughness electrolytic copper foil, and the gloss of the electrolytic copper foil is lowered, when the content of the above-mentioned additive D is more than 40 ppm. The precipitation state of the electrolytic copper foil becomes unstable and hinders the tensile strength of the electrolytic copper foil.

The above thiourea compound may be selected from the group consisting of diethyl thiourea, ethylene thiourea, and acetylene. Thiourea, dipropyl thiourea, dibutyl thiourea, N-trifluoroacetylthiourea, N-ethylthiourea, N-cyanoacetyl thiourea N-cyanoacetylthiourea), N-allylthiourea, o-tolylthiourea, N,N'-butylene thiourea, thiazolidine In thiazolidinethiol, 4-thioazolinethiol, 4-methyl-2-pyrimidinethiol, 2-thiouracil One or more, but not limited thereto, may be any thiourea compound which can be used as an additive in the art. The compound having a thiol group attached to the above nitrogen-containing hetero ring may be, for example, 2-mercapto-5-benzoimidazole sulfonic acid sodium salt, 3-(5- Sodium 3-(5-mercapto-1-tetrazolyl)benzene sulfonate, 2-mercapto benzothiazole.

The sulfonic acid or the metal salt thereof of the above sulfur atom-containing compound may be selected, for example. From bis-(3-sulfopropyl)-disulfide disodium salt (SPS), 3-mercapto-1-propanesulfonic acid (MPS), 3-(N,N-dimethylthiocarbamidine )-Sodium thiopropane sulfonate (DPS), 3-[(amino-iminomethyl)sulfide ]]-1-propanesulfonic acid sodium salt (UPS), o-ethyldithiocarbonate-S-(3-sulfopropyl)-ester sodium salt (OPX), 3-(benzothiazolyl-2-fluorenyl) Sodium propyl-sulfonate (ZPS), Ethylenedithiodipropylsulfonic acid sodium salt, Thioglycolic acid, thiophosphoric acid o-ethyl-bis-(ω- Thiophosphoric acid-o-ethyl-bis-(ω-sulfopropyl) ester disodium salt, thiophosphoric acid-tris-(ω-sulfopropyl) ester trisodium salt (Thiophosphoric acid-tris) One or more of -(ω-sulfopropyl)ester trisodium salt) is not limited thereto, and may be any sulfonic acid or a metal salt thereof containing a sulfur atom-containing compound which can be used as an additive in the technical field of the present invention.

The nonionic water-soluble polymer may be selected from the group consisting of polyethylene glycol and polyglycerin. Hydroxyethyl cellulose, Carboxymethylcellulose, Nonylphenol polyglycol ether, Octanediol-bis-(polyalkylene glycol ether) (Octane diol-bis) -(polyalkylene glycol ether)), Octanol polyalkylene glycol ether, Oleic acid polyglycol ether, Polyethylene propylene glycol, Polyethylene Polyethylene glycol dimethyl ether, polyoxypropylene glycol, polyvinyl alcohol, β-naphthol polyglycol ether, stearic acid One or more of Stearic acid polyglycol ether and Stearyl alcohol polyglycol ether, but is not limited thereto, as long as it can be used as an additive in the technical field of the present invention. Water soluble polymers can be used. For example, the above polyethylene glycol may have a molecular weight of from 2,000 to 20,000.

The phenazine-based compound may be one or more selected from the group consisting of Safranine-O, Janus Green B, and the like.

The temperature of the copper electrolytic solution used in the above production method may be 30 to 60 ° C, but is not limited to such a range, and it can be appropriately adjusted within a range in which the object of the present invention can be achieved. For example, the temperature of the above copper electrolyte may be 40 to 50 °C.

The current density used in the above production method may be 20 to 500 A/dm ² , but is not limited to such a range, and may be appropriately adjusted within a range in which the object of the present invention can be achieved. For example, the above current density may be 30 to 40 A/dm ² . The copper electrolyte may be a copper sulfonate-sulfonate copper electrolyte. In the above copper sulfonate-sulfonate copper electrolytic solution, the concentration of the above Cu ²⁺ ions may be from 60 g/L to 180 g/L, but is not limited to such a range, and may be in a range capable of achieving the object of the present invention. Adjust properly inside. For example, the concentration of the above Cu ²⁺ ions may be from 65 g/L to 175 g/L.

The copper electrolyte described above can be produced by a known method. For example, the concentration of Cu ²⁺ ions can be obtained by adjusting the addition amount of copper ions or copper sulfonate ions, and the concentration of SO ₄ ²⁺ ions can be obtained by adjusting the addition amount of sulfonic acid and copper sulfonate.

The concentration of the additive contained in the above copper electrolyte can be cast through the copper electrolyte The amount of the additive to be added and the molecular weight are obtained, or are obtained by analyzing an additive contained in the copper electrolytic solution by a known method such as column chromatography.

The method for producing the above-mentioned electrolytic copper foil can be used in addition to the above copper electrolytic solution. It is manufactured by a known method.

For example, the above-mentioned electrolytic copper foil can pass through a titanium curved surface on a rotating titanium material drum. The copper electrolytic solution was supplied between the upper cathode surface and the anode and electrolyzed to deposit an electrolytic copper foil on the surface of the cathode, and this was continuously crimped to produce an electrolytic copper foil.

The present invention will be described in more detail below by way of examples, but the invention It is not limited to this.

[Manufacture of electrolytic copper foil] Example 1

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

In order to smoothly move the Cu ²⁺ ions, gold plating was performed at a current density of 35 A/dm ² to produce an electrolytic copper foil having a thickness of 18 μm.

The basic composition of the copper electrolyte is as follows: CuSO ₄ . 5H ₂ O: 250~400g/L

H ₂ SO ₄ : 80~150g/L

Chloride ions and additives were added to the above copper electrolyte, and the additives and chloride components added are shown in Table 1 below. The ppm in Table 1 below is the same concentration as mg/L.

A scanning electron micrograph of the surface of the deposited copper foil deposition surface (matte surface, M surface) was shown in Fig. 7.

Examples 2 to 4 and Comparative Examples 1 to 4

An electrolytic copper foil was produced in the same manner as in Example 1 except that the composition of the copper electrolytic solution was changed as shown in the following Table 1. Scanning electron micrographs of the surface of the deposition surface of the electrolytic copper foils produced in Examples 2 to 4 and Comparative Examples 1 to 4 are shown in Figs. 8 to 14, respectively.

In the above Table 1, the abbreviations indicate the following compounds.

DET: diethyl thiourea

SPS: bis-(3-sulfopropyl)-disulfide disodium salt

MPS: 3-mercapto-1-propanesulfonic acid

PEG: polyethylene glycol (kanto chemical Cas No.25322-68-3)

ZPS: sodium 3-(benzothiazolyl-2-indenyl)-propyl-sulfonate

JGB: Jianna Green B

2M-SS: 2-mercapto-5-benzimidazole sulfonic acid

DDAC: diallyldimethylammonium chloride

PGL: Polyglycerol (KCI, PGL 104KC)

Evaluation Example 1: Scanning Electron Microscopy Experiment

With respect to the surfaces of the deposition faces of the electrolytic copper foils obtained in Examples 1 to 4 and Comparative Examples 1 to 4, a scanning electron microscope was measured and the results thereof are shown in Figs. 7 to 14, respectively.

As shown in FIGS. 7 to 14, the electrolytic copper foils of Examples 1 to 4 had a flat surface and a low roughness as compared with the electrolytic copper foils of Comparative Examples 1 to 4.

Evaluation Example 2: Determination of gloss

The glossiness of the surface of the deposition surface of the electrolytic copper foil obtained in Examples 1 to 4 and Comparative Examples 1 to 4 was measured. The above glossiness is a value measured in accordance with JIS Z 871-1997.

In the measurement of the glossiness, the measurement light was irradiated on the surface of the copper foil at an incident angle of 60° along the flow direction (MD direction) of the electrodeposited copper foil, and the intensity of light reflected at a reflection angle of 60° was measured. The measurement was carried out in accordance with JIS Z 8741-1997 as a method for measuring glossiness.

The measurement results are shown in Table 2 below.

As described in the above Table 2, the electrolytic copper foils of Examples 1 to 4 exhibited improved glossiness as compared with the electrolytic copper foils of Comparative Examples 1 to 4.

Evaluation Example 3: XRD experiment

The deposition faces of the electrolytic copper foils obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were measured. XRD (X-ray diffraction) spectrum. The XRD spectrum for Example 1 is shown in Fig. 6.

As shown in Fig. 6, the (111) crystal plane has the highest peak intensity, followed by the (200) crystal plane.

The ratio I(200)/I(111) of the intensity I (200) to the diffraction peak of the (200) crystal plane and the intensity I (111) of the diffraction peak of the (111) crystal plane was 0.605.

Further, in the XRD spectrum of the precipitated surface, the orientation index (M) of the (111), (200), (220), (311), and (222) crystal faces was measured, and the result was obtained. Shown in Table 3.

The orientation coefficient was measured using an orientation coefficient (M) proposed in S. Yoshimura, S. Yoshihara, T. Shirakashi, E. Sato, Electrochim. Acta 39, 589 (1994).

For example, in the case of a test piece having a (111) plane, an orientation index (M) is calculated by the following method.

IFR(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 card (Cards), and I (111) is the experimental value. When M(111) is greater than 1, it has a preferential orientation parallel to the (111) plane, and when M is less than 1, it indicates that the priority orientation is reduced.

Referring to Table 3 above, in the XRD spectrum for the above-mentioned precipitation surface, the orientation coefficient (M (200)) for the (200) crystal plane and the orientation coefficient (M (111)) for the (111) crystal plane were obtained. The ratio of orientation coefficients M (200) / M (111) was 1.31.

Evaluation Example 4: Measurement of surface roughness Rz

The precipitation surface and the gloss surface roughness Rz and Ra of the electrolytic copper foils obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were measured in accordance with JIS B 0601-1994. The surface roughness Rz and Ra obtained by the above measurement methods are shown in Table 4 below. Among them, the smaller the value, the thicker The lower the roughness.

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

The electrolytic copper foils obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were subjected to tensile test pieces at a width of 12.7 mm × a gauge length of 50 mm, and then at a cross head speed of 50.8 mm/min and in accordance with IPC- The TM-650 2.4.18B standard is subjected to a tensile test, and the maximum load of the measured tensile strength is referred to as normal temperature tensile strength, and the elongation at break is referred to as normal temperature elongation. Among them, the normal temperature is 25 ° C.

The electrolytic copper foil which is the same as the electrolytic copper foil used for measuring the tensile strength and the elongation at normal temperature was heat-treated at 180 ° C for 1 hour, and then taken out, and the tensile strength and elongation were measured in the same manner as above, and it was called It is high temperature tensile strength and high temperature elongation.

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

As shown in the above Table 4, the electrodeposited copper foils of Examples 1 to 4 had a surface roughness Rz of less than 0.5 μm and were low, and the tensile strength after high-temperature heat treatment was 40 kgf/mm 2 or more, and the elongation after high-temperature heat treatment was mostly More than 10% and higher.

On the other hand, the electrolytic copper foils of Comparative Examples 1 to 4 have higher surface roughness than the electrolytic copper foils of Examples 1 to 4, and the elongation after high-temperature heat treatment is low, which is not suitable. It is used as a cathode current collector for secondary batteries and/or a low-roughness copper foil for PCB/FPC.

Evaluation Example 6: Measuring the degree of curl of the corners

The electrolytic copper foils obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were subjected to a test piece having a width of 10 cm × a length of 10 cm, and then placed on a flat floor, and the angle at which the corner portions were bent was measured (the corner curl angle) And the height (corner curl height) of the cut portion after cutting in the X shape, and is shown in Table 5 below.

As shown in Table 5, the electrodeposited copper foils of Examples 1 to 4 had a corner curl angle of 5 to 30° and 45° or less. However, the angle of curl of the corners of the electrodeposited copper foil of Comparative Example 1 to Comparative Example 4 was 46 to 52°, and more than 45°, showing a state in which it was difficult to operate in a subsequent process. Meanwhile, the electrodeposited copper foils of Comparative Examples 1 to 4 had a corner curl height of more than 40 mm and exhibited a state of poor quality. Thus, the electrodeposited copper foil of the present invention has high strength and low internal pressure and less curling of the corners, and exhibits excellent performance.

The present invention is not limited to the above-described embodiments and the accompanying drawings, but should be construed as the scope of the invention. In addition, it will be understood by those skilled in the art that the present invention may be modified, modified, and modified in various forms without departing from the scope of the invention.

Claims (18)

An electrolytic copper foil in which the average diameter of the pores in the region between the convex surface elements as the deposition surface is from 1 nm to 100 nm. The electrolytic copper foil according to claim 1, wherein a cross-sectional area of the pores is from 10% to 50% with respect to an area of the precipitation surface. The electrolytic copper foil according to claim 1, wherein the pores are from 100 / μm ² to 1000 / μm ² . The electrolytic copper foil according to claim 1, wherein an average density of the pores in the precipitation surface is 10% to 50% of an average density of the convex surface elements in the precipitation surface %. The electrolytic copper foil according to the first aspect of the invention, wherein the gloss in the width direction of the deposition surface, that is, Gs (60°) is 500 or more. The electrolytic copper foil according to claim 1, wherein the tensile strength before the heat treatment is from 40 kgf/mm ² to 70 kgf/mm ² . The electrolytic copper foil according to claim 1, wherein the tensile strength after the heat treatment is from 40 kgf/mm ² to 70 kgf/mm ² . The electrolytic copper foil according to claim 1, wherein the tensile strength after heat treatment at 180 ° C for 1 hour is 40 kgf / mm ² to 70 kgf / mm ² or more. The electrolytic copper foil according to claim 1, wherein the tensile strength after the heat treatment is 85% to 99% of the tensile strength before the heat treatment. The electrolytic copper foil according to claim 1, wherein the elongation before the heat treatment is 2% to 15%. The electrolytic copper foil according to claim 1, wherein the elongation after the heat treatment is 4% to 15%. The electrolytic copper foil according to claim 1, wherein the elongation after heat treatment at 180 ° C for 1 hour is 4% to 15%. The electrolytic copper foil according to claim 1, wherein the elongation after the heat treatment is from 1 to 4.5 times the elongation before the heat treatment. The electrolytic copper foil according to claim 1, wherein the corner curling angle is from 0° to 45°. The electrolytic copper foil according to claim 1, wherein the electrodeposited copper foil has a corner curl height of from 0 mm to 40 mm. The electrolytic copper foil according to claim 1, wherein the electrolytic copper foil has a thickness of from 2 μm to 10 μm. A battery comprising the electrolytic copper foil according to any one of claims 1 to 16. An electrical component, comprising: an insulating substrate; and an electrolytic copper foil according to any one of claims 1 to 16, which is attached to a surface of the insulating substrate.