JP2016160503A - Electrolytic copper foil, and electrical component and battery comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: low-roughness electrolytic copper foil that allows high elongation in spite of thin thickness and high mechanical strength; and an electrical component and a battery that comprise the electrolytic copper foil.SOLUTION: An electrolytic copper foil is presented in which the average diameter of pores is from 1 nm to 100 nm, the pores being regions between protruding surface elements on a deposition face. The electrolytic copper foil exhibits a high elongation percentage while maintaining low roughness and high strength, and can be used in, e.g., a semiconductor packaging substrate for tape automated bonding (TAB) used in a tape carrier package (TCP) and a collector of a medium to large scale lithium ion secondary battery.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an electrolytic copper foil, an electrical component including the electrolytic copper foil, and a battery. More specifically, the present invention relates to low roughness, high strength, and high strength that simultaneously have high tensile strength and stretch ratio even after high-temperature heat treatment. The present invention relates to a drawn electrolytic copper foil.

  A copper foil is generally used as the current collector of the secondary battery. As the copper foil, a rolled copper foil obtained by rolling is mainly used, but the manufacturing cost is expensive and it is difficult to produce a wide copper foil. In addition, since the rolled copper foil must use a lubricating oil during the rolling process, the adhesion with the active material may deteriorate due to contamination of the lubricating oil, and the charge / discharge cycle characteristics of the battery may deteriorate.

  Lithium batteries are accompanied by a change in volume during charging and discharging and a heat generation phenomenon due to overcharging. In addition, the adhesion with the electrode active material is improved, the influence on the copper foil base material is less related to the expansion and contraction of the active material layer due to the charge / discharge cycle, the copper foil as a current collector is wrinkled, broken, etc. The surface roughness of the copper foil must be low so that there is an effect of preventing the occurrence of. Accordingly, there is a demand for a highly stretched, high strength and low roughness copper foil that can withstand volume changes and exothermic phenomena of lithium batteries and has excellent adhesion to the active material.

  In addition, due to the demands for light and thin electronic devices, there is an increasing demand for miniaturization of semiconductor mounting boards and main board boards in order to increase the degree of circuit integration within a small area due to high functionality, miniaturization, and weight reduction. Yes. When a thick copper foil is used for the production of a printed wiring board having such a fine pattern, the etching time for forming a wiring circuit becomes long, and the verticality of the side wall of the wiring pattern is lowered. In particular, when the line width of the wiring pattern formed by etching is narrow, the wiring may be disconnected. Therefore, in order to obtain a fine pitch circuit, a thinner copper foil is required. However, since the thickness of the thin copper foil is limited, the mechanical strength is weak, and the frequency of occurrence of defects such as wrinkles and bending is increased during the production of the printed wiring board.

  In a TAB (Tape Automated Bonding) semiconductor packaging substrate used for TCP (Tape Carrier Package), an inner lead (inner) disposed in a device hole located at the center of the product. lead), a plurality of terminals of the IC chip are directly bonded, and at this time, an electric current is instantaneously applied using a bonding apparatus to heat and a certain pressure is applied. Therefore, the inner lead formed by etching the electrolytic copper foil is stretched by being pulled by the bonding pressure.

  Accordingly, there is a demand for a low-roughness copper foil that is thin and has high mechanical strength but can be drawn at a high rate.

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

  Another aspect of the present invention provides an electrical component that includes an electrolytic copper foil.

  Yet another aspect of the present invention provides a battery including an electrolytic copper foil.

  In order to achieve the above object, the electrolytic copper foil according to one aspect of the present invention has a pore having an average diameter of 1 nm to 100 nm, which is a region between protruding surface elements.

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

  The ratio of the average density at the pore precipitation surface to the average density at the precipitation surface of the protruding surface element may be 10% to 50%.

  The glossiness (Gs (60 °)) in the width direction of the deposition surface may be 500 or more.

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

  The electrolytic copper foil may have a stretch ratio before heat treatment of 2% to 15%, and a stretch ratio after heat treatment of 4% to 15%. The heat treatment may be performed at 180 ° C. for 1 hour. Furthermore, the stretch ratio after heat treatment may be 1 to 4.5 times the stretch ratio before heat treatment.

  The corner winding angle of the electrolytic copper foil may be 0 ° to 45 °, the corner winding 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 including the above electrolytic copper foil is proposed.

  According to still another aspect of the present invention, an electrical component including an insulating base and the electrolytic copper foil attached to one surface of the insulating base is proposed.

  The electrolytic copper foil of the present invention has relatively small pore size and density between surface elements protruding outward from the deposition surface, and exhibits high gloss before the post-treatment process, improving the quality of the product There is an effect to make. In addition, the electrolytic copper foil according to the present invention exhibits a high drawing ratio while exhibiting high strength, and the internal stress of the electrolytic copper foil is small, thereby preventing the corner winding phenomenon. Therefore, the electrolytic copper foil according to the present invention exhibits low roughness, high strength, and high stretch ratio, and is advantageous in executing the process, reducing the defective rate of the product, and negative electrode current collector of PCB or secondary battery When used in a product such as, the reliability of the product can be improved.

It is a field emission scanning electron microscope (FESEM) image of 2,000 times of the electrolytic copper foil concerning one Embodiment of this invention. It is a 10,000 times FESEM image of the electrolytic copper foil concerning one Embodiment of this invention. It is a 50,000 times FESEM image of the electrolytic copper foil concerning one Embodiment of this invention. It is a 100,000 times FESEM image of the electrolytic copper foil concerning one Embodiment of this invention. It is a 100,000 times FESEM image of the electrolytic copper foil concerning one Embodiment of this invention. 3 is an XRD (X-ray diffraction) spectrum with respect to the deposition surface of the electrolytic copper foil produced in Example 1. FIG. 2 is a scanning electron microscope (SEM) image of the surface of the electrolytic copper foil manufactured in Example 1. FIG. 3 is a SEM image of the surface of the electrolytic copper foil of Example 2. 4 is a SEM image of the surface of the electrolytic copper foil of Example 3. 4 is a SEM image of the surface of the electrolytic copper foil of Example 4. 3 is a SEM image of the surface of the electrolytic copper foil of Comparative Example 1. 4 is a SEM image for the surface of the electrolytic copper foil of Comparative Example 2. 4 is a SEM image of the surface of the electrolytic copper foil of Comparative Example 3. 6 is a SEM image of the surface of the electrolytic copper foil of Comparative Example 4.

  Hereinafter, the electrolytic copper foil according to the present invention, electric parts and batteries including the electrolytic copper foil, and a method for producing the electrolytic copper foil will be described in more detail.

  In the electrolytic copper foil according to an embodiment of the present invention, the average diameter of the pore, which is a region between the protruding surface elements of the matte side, is 1 nm to 100 nm. In the electrolytic copper foil according to the present embodiment, the average diameter of pores, which are dark portions visible on the deposition surface, that is, dark portions existing between two surface elements, is small in nm units. In this specification, “surface element” means a bright portion that appears on the deposition surface and protrudes from the surface of the electrolytic copper foil, and “pore” means a surface that protrudes upward from the surface of the electrolytic copper foil. It means the part that is formed between the elements and is drawn into the interior and looks dark.

  The electrolytic copper foil according to the present invention may have a glossiness (Gs (60 °)) of 500 or more in the width direction of the deposition surface. That is, the glossiness of the deposited surface of the electrolytic copper foil is very high. Electrolytic copper foil is obtained by supplying a current between a rotating cathode drum immersed in a copper electrolyte bath and an anode, and depositing copper foil on the surface of the cathode drum. The surface in contact with the surface is a glossy surface (Shiny side, S surface), and the opposite surface is called a precipitation surface. Unlike the glossy surface that comes into contact with the drum, the deposited surface is a surface on which the electrolyzed copper foil is deposited as it is, so that in principle there is little light selection and the surface roughness is high. Therefore, the deposited surface is subjected to a post-treatment to reduce the surface roughness and to give a gloss as necessary.

  However, the glossiness of the deposited surface of the electrolytic copper foil according to the present invention is high. FIG. 1 is a field emission scanning electron microscope (FESEM) image of an electrolytic copper foil according to an embodiment of the present invention at a magnification of 2,000.

  In general, when the FESEM analysis of 2,000 times is performed on the deposited surface, unevenness appears on the surface and the glossiness is not high due to the characteristics of the process. On the other hand, in FIG. 1, the deposition surface of the electrolytic copper foil according to the present invention shows a mirror-like luster similar to the glossy surface.

  Increasing the resolution of the FESEM analysis and analyzing the 10,000 times FESEM image in FIG. 2, the 50,000 times FESEM image in FIG. 3, and the 100,000 times FESEM image in FIG. Unevenness appears on the surface. However, it is difficult to confirm the unevenness from the 10,000 times FESEM image, and the unevenness is confirmed at ultrahigh resolution such as 50,000 times FESEM and 100,000 times FESEM analysis.

  The 100,000 times FESEM image of FIG. 4 shows pores, which are regions between protruding surface elements on the deposited surface of the electrolytic copper foil. In FIG. 4, the electrolytic copper foil according to the present invention has a uniform surface element size and height on the deposition surface, a small pore diameter, and a relatively uniform pore size. FIG. 5 shows the result of FESEM analysis performed by tilting the same sample by 52 degrees and performing 100,000-fold FESEM analysis. In FIG. 5, the pores between the protruding surface elements are more clearly shown.

  Even when the surface has the same surface roughness, the surface glossiness is improved if the pore size is small or the number thereof is small. For example, when the pore volume on the deposition surface is the same and the pore depth is low and the average diameter is large, pores that are dark regions appearing on the surface can have a greater effect on glossiness. That is, if the pore volume is the same, but the pore depth is deep and the average diameter is small, the glossiness can be improved.

  Therefore, it is preferable in terms of glossiness that the pores on the deposition surface of the electrolytic copper foil according to the present invention have a relatively deep depth and a small average diameter. When considering the point that the surface roughness Rz is 1.4 μm or less on the precipitation surface, the average pore diameter is 1 nm to 100 nm. The pore depth is so that a dark portion of the pore is not exposed to the precipitation surface. Mean deep.

Moreover, the pore can show a cross-sectional area of 10% to 50% with respect to the entire area of the precipitation surface. This means that the pore preferably exhibits an area of 50% or less with respect to the entire area of the precipitation surface. At the same time, the ratio of the average density at the precipitation surface of the pores to the average density at the precipitation surface of the protruding surface elements may be 10% to 50%. It is preferable in terms of glossiness that the pores are present in a smaller number than the surface elements protruding outward. The pores may be 100 / μm ^{2 to} 1000 / μm ² .

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

The electrolytic copper foil according to an exemplary embodiment has a surface roughness Rz of the deposited surface of 1.4 μm or less, a tensile strength after heat treatment of 40 kgf / mm ² or more, and a draw ratio of 4% or more. .

The electrolytic copper foil has a high mechanical strength because it has a high tensile strength of 40 kgf / mm ² or more even though it is a low-roughness copper foil having a surface roughness Rz of 1.4 μm or less. At the same time, the electrolytic copper foil has a high stretch ratio of 4% or more even after high temperature.

  In addition, the electrolytic copper foil according to the present invention has a curl angle of 0 ° to 45 °. The corner winding angle means an angle at which the end portion of the electrolytic copper foil, that is, the corner or the periphery is bent, when the electrolytic copper foil is placed on a flat bottom. The corner winding phenomenon of the electrolytic copper foil is known to occur when the internal energy of the electrolytic copper foil is non-uniform. However, when corner winding occurs, the corner is rounded in a process such as lamination in the PCB process. Many defects such as tearing may occur, and in the lithium secondary battery process, problems such as corner breaks or breakage or wrinkles may occur during active material coating. If the winding angle of the corner of the electrolytic copper foil is large, it is difficult to use in the subsequent process. Therefore, the winding angle of the corner is preferably 0 ° to 45 °. Further, the electrolytic copper foil is spread on a flat bottom and cut into an X shape. The height at which the cut portion is lifted is referred to as the corner winding height, and the corner winding height is 0 mm to 40 mm. preferable. In the case of the electrolytic copper foil according to the present invention, since there is an impurity in the copper crystal and the strength is high, it is expected that the degree of corner winding is large, but there is no impurity at the copper crystal grain boundary, and internal stress Decreases and the degree of corner winding decreases.

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

  In the electrolytic copper foil, if the surface roughness Rz of the deposited surface exceeds 1.4 μm, the contact surface between the surface of the electrolytic copper foil for the negative electrode current collector and the active material becomes small, and the life of the charge / discharge cycle and The electric capacity at the initial stage of charging can be lowered. Moreover, if the surface roughness Rz of the precipitation surface exceeds 1.4 μm, it is not easy to form a high-density circuit having a fine pitch with a printed wiring board.

The electrolytic copper foil has a tensile strength of 40 kgf / mm ^{2 to} 70 kgf / mm ² and high strength characteristics. Further, the electrolyte copper foil, tensile strength after heat treatment is ^{40kgf / mm 2 ~70kgf / mm 2} . The heat treatment may be performed, for example, at 150 ° C. to 220 ° C., and in detail, may be performed at 180 ° C. The heat treatment may be performed for 30 minutes, 1 hour, 2 hours, and several hours, but a certain tensile strength can be maintained only after 1 hour or more. The heat treatment is for measuring the tensile strength of the electrolytic copper foil, and when the electrolytic copper foil is stored or put into a subsequent process, the tensile strength and the stretch ratio that are maintained at values that do not change to a certain level are set. It is a process to obtain.

If the tensile strength after heat treatment is less than 40 kgf / mm ² , the electrolytic copper foil may be difficult to handle due to its low mechanical strength.

  The electrolytic copper foil preferably has a tensile strength after heat treatment similar to that before heat treatment. The tensile strength after heat treatment of the electrolytic copper foil is preferably 85% to 99% of the tensile strength before heat treatment. However, if the strength is maintained even after the heat treatment, it is easy to handle in the subsequent process and yield. Becomes higher.

  The electrolytic copper foil may have a stretch ratio before heat treatment of 2% to 15%. The electrolytic copper foil may have a stretch rate of 4% to 15% after heat treatment, but the heat treatment may be performed at 180 ° C. for 1 hour. Alternatively, the stretch ratio after heat treatment may be 1 to 4.5 times the stretch ratio before heat treatment.

  In the electrolytic copper foil, if the stretch ratio after heat treatment is less than 4%, cracks may occur when the subsequent process is a high-temperature process. For example, when the electrolytic copper foil is used as a negative electrode current collector of a secondary battery, a crack is generated because the process during the production of the negative electrode current collector is a high-temperature process and the volume of the active material layer is changed during charging and discharging. In order to induce defects, a predetermined stretch ratio must be maintained after the heat treatment.

  The electrolytic copper foil has a ratio of the diffraction peak intensity (I (200)) to the (200) crystal plane and the diffraction peak intensity (I (111)) to the (111) crystal plane in the XRD spectrum with respect to the precipitation surface. I (200) / I (111) may be 0.5 to 1.0.

  For example, as shown in FIG. 6, in the XRD spectrum with respect to the precipitation surface, a diffraction peak with respect to the (111) crystal plane is shown at a diffraction angle (2θ) of 43.0 ° ± 1.0 °, and a diffraction angle (2θ) of 50.degree. A diffraction peak with respect to the (200) crystal plane is shown at 5 ° ± 1.0 °, and the intensity ratio I (200) / I (111) 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, an orientation index obtained from an orientation index (M (200)) relative to the (200) crystal plane and an orientation index (M (111)) relative to the (111) crystal plane in the XRD spectrum relative to the precipitation surface. The ratio of M (200) / M (111) may be 1.1 to 1.5. The orientation index is obtained by dividing the relative peak intensity of a specific crystal plane with respect to an arbitrary sample by the relative peak intensity of a characteristic crystal plane obtained from a non-oriented standard sample with respect to all crystal planes. It is the value. For example, in the electrolytic copper foil, M (200) / M (111) may be 1.2 to 1.4.

  The electrolytic copper foil may have a stretching ratio of 10% or more after heat treatment at 180 ° C. for 1 hour. That is, the electrolytic copper foil can have a high draw ratio of 10% or more after the high temperature heat treatment. For example, the electrolytic copper foil may have a stretching ratio of 10% to 20% after the high temperature heat treatment. For example, the electrolytic copper foil may have a stretching ratio of 10% to 15% after the high temperature heat treatment. For example, the electrolytic copper foil may have a stretching ratio of 10% to 13% after the high-temperature heat treatment. The electrolytic copper foil may have a stretching ratio of 2% or more before heat treatment. For example, the electrolytic copper foil may have a stretch ratio before heat treatment of 2% to 20%. For example, the electrolytic copper foil may have a stretch ratio before heat treatment of 5% to 20%. For example, the electrolytic copper foil may have a stretch ratio before heat treatment of 5% to 15%. For example, the electrolytic copper foil may have a stretching ratio of 5% to 10% before heat treatment. The term “before heat treatment” means 25 ° C. to 130 ° C., which is a temperature before heat treatment in a high temperature state. The stretch ratio is a value obtained by dividing the distance stretched until immediately before the electrolytic copper foil breaks by the initial length of the electrolytic copper foil.

  The electrolytic copper foil may have a surface roughness Rz of 0.7 μm or less on the deposition surface. The electrolytic copper foil can be used as a copper foil for PCB / FPC and a copper foil for a negative electrode current collector for a secondary battery by having a low roughness of Rz of 0.7 μm or less. For example, the electrolytic copper foil may have a surface roughness Rz of 0.5 μm or less. For example, the electrolytic copper foil may have a deposition surface with a surface roughness Rz of 0.45 μm or less.

  The electrolytic copper foil may have a deposition surface with a surface roughness Ra of 0.15 μm or less. The electrolytic copper foil can be used as a copper foil for PCB / FPC and a copper foil for a negative electrode current collector for a secondary battery because Ra has a low roughness of 0.15 μm or less. For example, the electrolytic copper foil may have a deposition surface with a surface roughness Ra of 0.12 μm or less. For example, the electrolytic copper foil may have a deposition surface with a surface roughness Ra of 0.11 μm or less.

The tensile strength after heat treatment of the 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 heat treatment is the tensile strength of the copper foil obtained without the high temperature heat treatment. The tensile strength before heat treatment of the electrolytic copper foil may be 40 kgf / mm ^{2 to} 70 kgf / mm ² .

  In the electrolytic copper foil, the gloss (Gs (60 °)) in the width direction of the deposition surface may be 500 or more. For example, in the electrolytic copper foil, the gloss (Gs (60 °)) in the width direction of the deposition surface may be 500 to 1000. The glossiness is a value measured according to JIS Z871-1997.

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

  When the electrolytic copper foil needs to be bonded to an insulating resin or the like, a surface treatment can be additionally performed in order to bring the adhesion to a practical level or higher. Examples of the surface treatment on the copper foil include any one of heat resistance and chemical resistance treatment, chromate treatment, silane coupling treatment, or a combination thereof. This is done by a person having ordinary knowledge in the technical field to which the present invention belongs according to the resin used as the insulating resin and the process conditions.

  An electrical component according to an exemplary embodiment includes an insulating substrate and the above-described electrolytic copper foil attached to one surface of the insulating substrate, and is a circuit formed by etching the electrolytic copper foil. including.

  The electrical component is, for example, a TAB tape, a printed wiring board (PCB), a flexible printed wiring board (FPC, Flexible PCB), etc., but is not necessarily limited thereto, and the electrolytic copper foil is placed on an insulating substrate. Any material can be used as long as it can be used in the technical field.

  A battery according to an exemplary embodiment includes the electrolytic copper foil. The electrolytic copper foil can be used as a negative electrode current collector of the battery, but is not necessarily limited thereto, and can be used as another component used in the battery. The battery is not particularly limited, and includes all primary batteries and secondary batteries, such as lithium ion batteries, lithium polymer batteries, lithium air batteries, and the like, which can be used in the technical field as batteries using an electrolytic copper foil as a current collector. If it is all possible.

  The method for producing an electrolytic copper foil according to an exemplary embodiment includes the step of electrolyzing a copper electrolyte solution containing additive A; additive B; additive C; and additive D, wherein the additive A is thiourea. One or more selected from the group consisting of a system compound and a compound in which a thiol group is linked to a nitrogen-containing heterocycle, and the additive B is a sulfonic acid of a compound containing a sulfur atom or a metal salt thereof, The additive C is a nonionic water-soluble polymer, and the additive D is a phenazinium compound.

By including an additive having a new composition, the electrolytic copper foil production method can produce a low-roughness copper foil that can be stretched while being thin and having high mechanical strength. The copper electrolyte may contain chlorine (chlorine ions) having a concentration of 1 to 40 ppm. If a small amount of chlorine ions are present in the copper electrolyte, the number of initial nucleation sites increases during electroplating, the crystal grains become finer, and the CuCl ₂ precipitate formed at the interface between the crystal grain boundaries is heated to a high temperature. Sometimes crystal growth can be suppressed to improve thermal stability at high temperatures. If the concentration of the chlorine ions is less than 1 ppm, the concentration of chloride ions required in the sulfuric acid-copper sulfate electrolyte is insufficient, the tensile strength before heat treatment is reduced, and the thermal stability at high temperature is reduced. There is. If the concentration of chloride ions exceeds 40 ppm, the surface roughness of the precipitation surface will increase and it will be difficult to produce low-roughness electrolytic copper foil, the tensile strength before heat treatment will decrease, and thermal stability at high temperatures will occur. May decrease.

  In the copper electrolyte, the content of the additive A 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 addition The content of the agent D may be 1 to 10 ppm.

  In the copper electrolyte, the additive A can improve the production stability 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 decrease. If the content of the additive A exceeds 10 ppm, the surface roughness of the precipitation surface increases. Therefore, it is difficult to produce a low roughness electrolytic copper foil, and the tensile strength may be lowered.

  In the copper electrolyte, additive B can improve the surface gloss of the electrolytic copper foil. If the content of the additive B is less than 10 ppm, the gloss of the electrolytic copper foil may decrease. If the content of the additive B exceeds 200 ppm, the surface roughness of the precipitation surface increases. Production of low-roughness electrolytic copper foil is difficult, and the tensile strength of the electrolytic copper foil may decrease.

  In the copper electrolyte, the additive C can reduce the surface roughness of the electrolytic copper foil and improve the surface gloss. If the content of the additive C is less than 5 ppm, the surface roughness of the precipitated surface is increased, making it difficult to produce a low roughness electrolytic copper foil, and the gloss of the electrolytic copper foil may be reduced. If the content of the additive C exceeds 40 ppm, there is no difference in physical properties and appearance of the electrolytic copper foil, which may not be economical.

  In the copper electrolyte, the additive D can play a role of improving 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 precipitation surface is increased, making it difficult to produce a low roughness electrolytic copper foil, and the gloss of the electrolytic copper foil may be reduced. If the content of the additive D exceeds 40 ppm, the deposited state of the electrolytic copper foil becomes unstable, and the tensile strength of the electrolytic copper foil may be hindered.

  The thiourea compounds include diethylthiourea, ethylenethiourea, acetylenethiourea, dipropylthiourea, dibutylthiourea, N-trifluoroacetylthiourea, N-ethylthiourea, N-cyanoacetylthiourea. N-cyanoacetylthiourea), N-allylthiourea, o-tolylthiourea, N, N'-butylenethiourea, thiazolthiol 4-thiazolthiol Thiol (4-thiazolinethiol), 4- It may be one or more selected from the group consisting of 4-methyl-2-pyrimidinethiol and 2-thiouracil, but is not necessarily limited thereto, and the technical field Any thiourea compound that can be used as an additive is possible. Examples of the compound in which a thiol group is linked to the nitrogen-containing heterocycle include 2-mercapto-5-benzimidazolesulfonic acid sodium salt (sodium 2-mercapto-5-benzimidazolide sodium salt), sodium 3- (5- It may be mercapto-1-tetrazolyl) benzenesulfonate (Sodium 3- (5-mercapto-1-tetrazolyl) benzonesulfonate), 2-mercaptobenzothiazole (2-mercaptobenzothiazole).

  Examples of the sulfonic acid or a metal salt thereof containing the sulfur atom include bis- (3-sulfopropyl) -disulfide disodium salt (SPS), 3-mercapto-1-propanesulfonic acid (MPS), 3- ( N, N-dimethylthiocarbamoyl) -thiopropanesulfonate sodium salt (DPS), 3-[(amino-iminomethyl) thio] -1-propanesulfonate sodium salt (UPS), o-ethyldithiocarbonate-S- (3- Sulfopropyl) -ester sodium salt (OPX), 3- (benzothiazolyl-2-mercapto) -propyl-sulfonic acid sodium salt (ZPS), ethylene dithiodipropyl sulfonic acid sodium salt (Ethylenedithiopropylsulfonic acid sodium) alt), thioglycolic acid, thiophosphoric acid-o-ethyl-bis- (ω-sulfopropyl) ester disodium salt (Thiophosphoric acid-o-ethyl-bis- (ω-sulfopropyl) ester disodium salt), It may be one or more selected from the group consisting of thiophosphoric acid-tris- (ω-sulfopropyl) ester trisodium salt (Thiophosphoric acid-tris- (ω-sulfopropyl) ester trisodium salt), but is not necessarily limited thereto. Any sulfonic acid or metal salt of a compound containing a sulfur atom that can be used as an additive in the art is possible.

  The nonionic water-soluble polymer may be polyethylene glycol, polyglycerin, hydroxyethyl cellulose, carboxymethyl cellulose (Carboxymethylcellulose), nonylphenol polyglycol ether, octanediol-bis- (polyalkylene glycol ether (Octane diol-bis). -(Polyalkylene glycol ether), octanol polyalkylene glycol ether (Ocatanol polyalkylene glycol ether), oleic acid polyglycol ether (Oleic acid polyglycol ether), polyethylene propylene glycol (Poly) polyethylene propylene glycol, polyoxypropylene glycol, polyoxypropylene glycol, polyoxypropylene glycol (polyether glycol), poly (propylene glycol), poly (propylene glycol), poly (propylene glycol), poly (propylene glycol) It may be one or more selected from the group consisting of (Stearic acid polyglycol ether) and stearyl alcohol polyglycol ether, but is not necessarily limited thereto. However, any water-soluble polymer that can be used as an additive in the technical field is possible, for example, the polyethylene glycol may have a molecular weight of 2000 to 20000.

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

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

The current density used in the manufacturing method may be ²⁰ to 500 A / dm ² , but is not necessarily limited to this range, and can be appropriately adjusted within a range in which the object of the present invention can be achieved. For example, the current density may be 30~40A / dm ^2. The copper electrolyte may be a sulfuric acid-copper sulfate electrolyte. In the sulfuric acid-copper sulfate electrolytic solution, the concentration of the Cu ²⁺ ions may be 60 g / L to 180 g / L, but is not necessarily limited to this range, and within the range in which the object of the present invention can be achieved. It can be adjusted as appropriate. For example, the Cu ²⁺ concentration may be 65 g / L to 175 g / L.

The copper electrolyte 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 sulfate, and the concentration of SO ₄ ²⁺ ions can be obtained by adjusting the addition amounts of sulfuric acid and copper sulfate.

  The concentration of the additive contained in the copper electrolyte can be obtained from the amount and molecular weight of the additive added to the copper electrolyte, or the additive contained in the copper electrolyte can be obtained by a known method such as column chromatography. It can be obtained by analyzing the method.

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

  For example, the electrolytic copper foil is supplied with the copper electrolyte between the cathode surface and the anode on the curved surface of titanium on a rotating titanium drum, electrolyzed, and the electrolytic copper foil is deposited on the cathode surface, This can be wound up continuously to produce an electrolytic copper foil.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not necessarily limited to this.

(Manufacture of electrolytic copper foil)
Example 1
In order to produce electrolytic copper foil by electrolysis, a 3 L capacity electrolytic cell system that can be circulated at 20 L / min was used, and the temperature of the copper electrolyte was kept constant at 45 ° C. The anode used was a DSE (Dimentionally Stable Electrode) plate having a thickness of 5 mm and a size of 10 × 10 cm ² , and the cathode was a titanium plate having the same size and thickness as the anode.

In order to make Cu ²⁺ ions move smoothly, 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
Chlorine ions and additives were added to the copper electrolyte, and the compositions of the added additives and chloride ions are shown in Table 1 below. In Table 1 below, ppm is the same concentration as mg / L.

  FIG. 7 shows a scanning electron micrograph of the surface of the produced electrolytic copper foil on the deposition surface (Matte surface, M surface).

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 electrolyte was changed as shown in Table 1 below. Scanning electron micrographs 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.

In Table 1, the abbreviations 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
SAO: Safranine-O
2M-SS; 2-mercapto-5-benzimidazolesulfonic acid DDAC: diallyldimethylammonium chloride PGL: polyglycerin (KCI, PGL104KC)

Evaluation Example 1: Scanning Electron Microscope Experiment A scanning electron microscope was measured on the surface of the deposited surface of the electrolytic copper foil obtained in Examples 1 to 4 and Comparative Examples 1 to 4, and the results were shown in FIGS. Respectively.

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

Evaluation Example 2: Measurement of Glossiness Glossiness was measured with respect to the surface of the deposited surface of the electrolytic copper foil obtained in Examples 1-4 and Comparative Examples 1-4. The glossiness is a value measured according to JIS Z871-1997.

  Glossiness is measured by irradiating the surface of the copper foil with measurement light at an incident angle of 60 ° along the flow direction (MD direction) of the electrolytic copper foil and measuring the intensity of the light reflected at a reflection angle of 60 °. Then, it measured according to JIS Z8741-1997 which is a measuring method of glossiness.

The measurement results are shown in Table 2 below.

  As described 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 An XRD (X-ray diffraction) spectrum was measured on the precipitation surfaces of the electrolytic copper foils obtained in Examples 1 to 4 and Comparative Examples 1 to 4. The XRD spectrum for Example 1 is shown in FIG.

  As shown in FIG. 6, the peak intensity of the (111) crystal plane was the highest, and the next was the (200) crystal plane.

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

  Further, in the XRD spectrum for the precipitation surface, the orientation index (M) for the (111), (200), (220), (311), (222) crystal plane was measured, and the result was expressed as follows: It is shown in Table 3.

  The orientation index is S.I. Yoshimura, S .; Yoshihara, T .; Shirakashi, E .; Sato, Electrochim. Measurement was performed using the orientation index (M) proposed in Acta 39, 589 (1994).

For example, in the case of a test piece having a (111) plane, the 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 an experimental value. If M (111) is greater than 1, it has a preferred orientation parallel to the (111) plane, and if M is less than 1, it means that the preferred orientation is reduced.

  Referring to Table 3, in the XRD spectrum with respect to the precipitation surface, it is obtained from the orientation index (M (200)) with respect to the (200) crystal plane and the orientation index (M (111)) with respect to the (111) crystal plane. The ratio of orientation index M (200) / M (111) was 1.31.

Evaluation Example 4 Measurement of Surface Roughness (Rz) The surface roughness Rz and Ra of the deposited and glossy surfaces of the electrolytic copper foils obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were determined according to JIS B0601-1994 standard. It was measured. The surface roughness Rz and Ra obtained by the above measuring 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 stretching ratio, high temperature tensile strength and high temperature stretching ratio The electrolytic copper foils obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were pulled at a width of 12.7 mm and a gauge length of 50 mm. After collecting the test piece, the tensile test was performed according to the IPC-TM-650 2.4.18B standard at a crosshead speed of 50.8 mm / min, and the maximum load of the tensile strength measured was normal temperature tensile strength, The stretch ratio at break was defined as the room temperature stretch ratio. Here, the normal temperature is 25 ° C.

  The same electrolytic copper foil as that used for measurement of tensile strength and stretch ratio at room temperature was taken out after heat treatment at 180 ° C. for 1 hour, and the tensile strength and stretch ratio were measured in the same manner as described above. The high-temperature tensile strength and the high-temperature stretch ratio were set.

  Table 4 below shows the room temperature tensile strength, the room temperature stretching ratio, the high temperature tensile strength, and the high temperature stretching ratio obtained by the measurement method.

As shown in Table 4, the electrolytic copper foils of Examples 1 to 4 have a low surface roughness Rz of less than 0.5 μm, a tensile strength after high temperature heat treatment of 40 kgf / mm ² or more, and after high temperature heat treatment. The stretch ratio was as high as 10% or more.

  On the other hand, the electrolytic copper foils of Comparative Examples 1 to 4 have a higher surface roughness than the electrolytic copper foils of Examples 1 to 4 and a low stretch ratio after the high-temperature heat treatment. It was unsuitable for use as a low roughness copper foil for body and / or PCB / FPC.

Evaluation Example 6: Measurement of curl degree About the electrolytic copper foils obtained in Examples 1 to 4 and Comparative Examples 1 to 4, after taking a test piece with a width of 10 cm × a length of 10 cm, a flat bottom Table 5 below shows the angle at which the corner portion is bent (corner winding angle) and the height of the cut portion (corner winding height) is measured after cutting into an X shape. It was shown to.

  As shown in Table 5, the electrolytic copper foils of Examples 1 to 4 had a corner winding angle of 5 to 30 ° and 45 ° or less. However, the electrolytic copper foils of Comparative Examples 1 to 4 had a corner winding angle of 46 ° to 52 ° and exceeded 45 °, indicating that it was difficult to handle in subsequent steps. At the same time, the electrolytic copper foils of Comparative Examples 1 to 4 showed a state in which the corner winding height exceeded 40 mm and the quality was poor. Therefore, the electrolytic copper foil according to the present invention showed excellent performance because it had high strength but low internal stress and reduced corner winding phenomenon.

  The present invention should not be limited by the above-described embodiments and the accompanying drawings, but should be interpreted by the appended claims. In addition, those having ordinary knowledge in the technical field that various forms of substitution, modification, and change are possible without departing from the technical idea of the present invention described in the claims of the present invention. It is self-evident.

Claims (18)

  An electrolytic copper foil, wherein an average diameter of a pore, which is a region between protruding surface elements of a deposition surface, is 1 nm to 100 nm.   2. The electrolytic copper foil according to claim 1, wherein a cross-sectional area of the pore is 10% to 50% with respect to an area of the deposition surface. ^2. The electrolytic copper foil according to claim 1, wherein the number of pores is 100 / μm ^{2 to} 1000 / μm ² .   2. The electrolytic copper foil according to claim 1, wherein an average density of the pores on the deposition surface is 10% to 50% of an average density of the protruding surface elements on the deposition surface.   The electrolytic copper foil according to claim 1, wherein the degree of gloss (Gs (60 °)) in the width direction of the deposition surface is 500 or more. ^2. The electrolytic copper foil according to claim 1, wherein the tensile strength before the heat treatment is 40 kgf / mm ^{2 to} 70 kgf / mm ² . ^2. The electrolytic copper foil according to claim 1, wherein the tensile strength after the heat treatment is 40 kgf / mm ^{2 to} 70 kgf / mm ² . ^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 .   2. 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 a stretch ratio before heat treatment is 2% to 15%.   The electrolytic copper foil according to claim 1, wherein the stretch ratio after heat treatment is 4% to 15%.   2. The electrolytic copper foil according to claim 1, wherein a stretch ratio after heat treatment at 180 ° C. for 1 hour is 4% to 15%.   2. The electrolytic copper foil according to claim 1, wherein the stretch ratio after the heat treatment is 1 to 4.5 times the stretch ratio before the heat treatment.   The electrolytic copper foil according to claim 1, wherein the angle winding angle is 0 ° to 45 °.   The electrolytic copper foil according to claim 1, wherein a corner winding height is 0 mm to 40 mm.   The electrolytic copper foil according to claim 1, wherein the thickness is 2 μm to 10 μm.   A battery comprising the electrolytic copper foil according to claim 1. An insulating substrate;
An electrical component comprising the electrolytic copper foil according to any one of claims 1 to 16, which is attached to one surface of the insulating substrate.