KR20150077944A - Copper foil, electric component and battery comprising the foil - Google Patents

Abstract

Suggested is a copper foil with low brightness and superior bonding strength. A recess is formed at least one surface of the copper foil. Micro particles are formed on the surface. Upper micro particles located on the average line are larger than lower micro particles located under the average line according to the average height of the surface.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a copper foil, an electric component including the copper foil,

The present invention relates to a copper foil, an electric component including the copper foil, and a battery, and more particularly to a copper foil having a low roughness and excellent adhesive strength.

A laminate for a printed circuit board used in the electronics industry is formed by impregnating a glass cloth, a kraft paper or a glass fiber nonwoven fabric with a thermosetting resin such as a phenolic resin or an epoxy resin, And then laminating the copper foil on one side or both sides of the prepreg. The multilayer printed wiring board is manufactured by forming a circuit on both sides of a copper-clad laminate to form an inner layer material, and laminating the copper foil on both sides of the inner layer material through a prepreg.

When the copper foil is laminated on one side or both sides of the prepreg, the adhesion rate is not sufficient due to the difference between the materials, so that the copper foil is separated from the prepreg in the subsequent process, resulting in defective products. Therefore, a surface treatment is performed on the copper foil to improve adhesion to a resin such as a prepreg.

The copper foil used in the production of the printed wiring board is subjected to a coarsening treatment in which unevenness is formed by adhering fine copper particles to one surface. When bonding with a resin such as a prepreg is carried out, the roughened shape of the roughened copper foil is embedded in the base resin to provide an anchoring effect, so that the adhesion between the copper foil and the base resin is improved.

In recent years, demand for wiring density of printed wiring boards has also increased year by year due to the effect of thinning and high performance of electronic devices incorporating printed wiring boards. It is required to improve the quality of the product and the circuit formed by the etching is also highly advanced so that a circuit etching factor is required to be able to completely control the impedance.

When the surface treatment of the copper foil is performed as described above, the surface roughness of the copper foil is increased and the adhesion between the copper foil and the base resin is improved, but the etching property to the fine circuit can be lowered. Therefore, it is required to develop a technique that can improve the adhesion while maintaining the surface roughness of the copper foil in consideration of the etching property.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a copper foil having a low roughness and excellent adhesive strength.

In order to achieve the above object, a copper foil according to an aspect of the present invention is a copper foil having concave and convex portions formed on at least one surface thereof and having a fine particle layer formed on its surface, Is higher than the lower fine particles located below the average line.

The ratio of the number of upper fine particles to the number of lower fine particles may be 80:20 to 100: 0.

The upper fine particle can form a triangle by connecting the center points.

The diameter of the fine particles may be between 1 and 3 탆.

The fine particles may be metal particles or copper alloy particles containing at least one metal of copper (Cu), iron (Fe), molybdenum (Mo) and cobalt (Co)

The peel strength of the copper foil may be 1.28 to 1.33 kgf / cm, the surface roughness Rz may be 5.2 to 6.5 mu m, and the surface roughness Rmax may be 6.5 to 7.7 mu m.

According to another aspect of the present invention, there is provided a semiconductor device comprising: an insulating substrate; And a copper foil as described above attached to one surface of an insulating base material.

According to another aspect of the present invention, there is provided a battery including the above-described copper foil.

According to still another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a copper foil having concave and convex portions formed on at least one surface thereof; And forming a fine particle layer on the uneven surface, wherein the fine particle layer is formed such that the upper fine particle located on the average line along the average height of the surface is larger than the lower fine particle located below the average line. A surface treatment method is provided.

The step of forming the fine particle layer includes the steps of: Sulfuric acid; And a metal containing iron (Fe), molybdenum (Mo), and cobalt (Co) to form a fine particle layer on the surface on which irregularities are formed.

The content of iron may be 10 to 30 g, the content of molybdenum may be 0.5 to 10 g, and the content of cobalt may be 1 to 15 g. The electroplating process for forming the fine particle layer may be performed at 20 to 60 A / dm < ² > for 1 to 5 seconds.

The copper foil according to the present invention has a low roughness and an excellent adhesive strength. Accordingly, while the etching property for forming the microcircuit substrate is ensured, the adhesive strength is excellent, and the adhesion with the resin and the like is improved, thereby improving the reliability of the product when manufacturing the product using the copper foil.

1 is a view showing a surface of a copper foil according to an embodiment of the present invention.
Fig. 2 is a view showing the surface of the copper foil except the fine particles in Fig. 1. Fig.
Fig. 3 is a view showing a part of the surface of the copper foil in Fig. 1. Fig.
4 is a scanning electron microscopy (SEM) image of the surface of the copper foil surface-treated in Example 1. Fig.
5 is an SEM image of the surface of the copper foil of Example 2. Fig.
6 is an SEM image of the surface of the copper foil of Example 3. Fig.
7 is an SEM image of the surface of the copper foil of Example 4. Fig.
8 is an SEM image of the surface of the copper foil of Comparative Example 1. Fig.
9 is an SEM image of the surface of the copper foil of Comparative Example 2. Fig.
10 is an SEM image of the surface of the copper foil of Comparative Example 3. Fig.

Hereinafter, the copper foil according to the preferred embodiments, the electric part including the copper foil and the battery, and the method of treating the surface of the copper foil will be described in more detail.

FIG. 1 is a view showing a surface of a copper foil according to an embodiment of the present invention. FIG. 2 is a view showing the surface of the copper foil except for fine particles in FIG. 1, and FIG. Fig. The copper foil according to this embodiment is a copper foil having irregularities on its surface and having a fine particle layer formed on its surface, wherein the upper fine particles located on the average line along the average height of the surface are larger than the lower fine particles located below the average line.

The copper foil according to the present invention has irregularities formed on its surface. The process for producing the copper foil is generally classified into a peeling process, that is, a process for producing the copper foil itself and a process for treating the surface of the produced copper foil. The copper foil produced according to the stamping process has different values depending on the process but has surface roughness. That is, it includes large irregularities on the surface in the case of high illuminance and small irregularities on the surface in case of low illuminance.

The surface including such concavities and convexities is subjected to various surface treatment processes as necessary to give necessary characteristics in a subsequent process. For example, when used as an FPCB or an anode current collector of a secondary battery, the surface can be roughened to increase the roughness in order to improve adhesion with a resin or an active material, and diffusion of copper particles into other layers The surface treatment may be carried out to enhance the adhesive strength by rust treatment to prevent surface oxidation or surface treatment with a silane coupling agent at the outermost periphery.

In order to enhance the adhesion between the copper foil and the resin or the active material, a roughening treatment is carried out to increase the surface roughness. In the roughening treatment, a fine particle layer may be formed on the surface of the copper foil to be in contact with the resin or the active material.

Referring to FIG. 1, the copper foil 100 is provided with concave and convex portions 120 on the surface of the copper foil layer 110, and the fine particles 131 form fine particle layers 130 on the concave and convex portions 120. Referring to FIG. 2, fine particles can be classified based on an average line m according to the average height of the protrusions 220 of the copper foil 210. That is, the fine particles located on the average line (m) are referred to as upper fine particles, and the fine particles located below the average line (m) may be referred to as lower fine particles.

In the copper foil 100 according to the present invention, the upper fine particles are larger than the lower fine particles. The upper fine particles are located at the mountain portion of the concave and convexes 120 and the lower fine particles are the fine particles located at the valleys of the concave and convexes 120. When the upper fine particle is larger than the lower fine particle or does not have the lower fine particle as in the case of the copper foil 100 of the present invention, the fine particle of the concavity and convexity 120 has little or no fine particles. Therefore, a vacant space is generated in the valley portion of the concavity and convexity 120, and the porosity is increased. In this empty space, for example, when the copper foil 100 is in contact with the resin or the active material, the resin or active material is filled in the void space, thereby improving the adhesion.

The reason for roughening the surface of the copper foil is that the surface of the copper foil, in which the roughening phenomenon becomes more severe due to the roughening treatment, is buried in the resin or the like to provide an anchor effect to improve the adhesion. However, in the case of the copper foil according to the present invention, in addition to the above, in addition to this, fine grains are less likely to be generated in the valleys between the mountains and the mountains of the irregularities to form voids. Fine particles are formed thereon, Thereby improving the adhesion.

For this purpose, it is preferable that the copper foil 210 be self-immersed in the upper portion of the average line m, and the lower portion thereof has a small amount of fine particles to ensure the maximum porosity. For example, the ratio of the number of upper fine particles to the number of lower fine particles may be 80:20 to 100: 0.

Further, in order to maximize the anchor effect, the upper fine particle may form a triangle connecting the center points. Referring to FIG. 3, three upper fine particles 331, 332 and 333 are located on the concave and convex 320, and the center shape 340 connecting the center points P ₁ , P ₂ and P ₃ thereof is a triangle .

The diameter of the fine particles may be between 1 and 3 탆. If the diameter of the fine particles is too small, the ratio of the lower fine particles can be increased by penetrating into the valleys of the irregularities. If the diameter of the fine particles is too large, the overall unevenness becomes large and the surface roughness of the copper foil is increased. .

The fine particles may be metal particles or copper alloy particles containing at least one metal of copper (Cu), iron (Fe), molybdenum (Mo) and cobalt (Co)

The peel strength of the copper foil may be 1.28 to 1.33 kgf / cm, the surface roughness Rz may be 5.2 to 6.5 mu m, and the surface roughness Rmax may be 6.5 to 7.7 mu m. In the copper foil according to the present invention, the fine particles formed on the concavo-convex portion are positioned on the acid portion in a concentrated manner, so that the surface roughness is low and the peel strength is high, so that the adhesion is improved.

According to another aspect of the present invention, there is provided a semiconductor device comprising: an insulating substrate; And a copper foil attached to one surface of the insulating base material. The copper foil contained in the electrical component includes a circuit formed by etching the copper foil.

Examples of such electrical parts include, but are not limited to, TAB tape, printed circuit board (PCB), flexible printed circuit board (FPC), and flexible printed circuit board Anything that can be used in.

According to still another aspect of the present invention, there is provided a battery including the above-described copper foil. The copper foil may be used as an anode current collector of a battery but is not limited thereto and may be used as other components used in a battery. The battery is not particularly limited and includes all the primary and secondary batteries, and is a battery using a copper foil as a current collector such as a lithium ion battery, a lithium polymer battery, and a lithium air battery. Any battery can be used in the related art Do.

According to still another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a copper foil having concave and convex portions formed on at least one surface thereof; And forming a fine particle layer on the uneven surface, wherein the fine particle layer is formed such that the upper fine particle located on the average line along the average height of the surface is larger than the lower fine particle located below the average line. A surface treatment method is provided.

In the method for treating a surface of a copper foil according to the present invention, Sulfuric acid; And a metal containing iron (Fe), molybdenum (Mo), and cobalt (Co) to form a fine particle layer on at least one surface of the copper foil having irregularities formed on its surface.

The surface treatment liquid contains 10 to 30 g of iron, 0.5 to 10 g of molybdenum and 1 to 15 g of cobalt. If the content of the metal contained in the surface treatment liquid is too small, it is difficult to control the ratio of the upper fine particles and the lower fine particles because the copper alloy is not sufficiently formed. When the metal content is too high, too much fine particles are formed, It may be disadvantageous in the etching property.

The electroplating process for forming the fine particle layer may be performed at 20 to 60 A / dm < ² > for 1 to 5 seconds.

The copper foil according to the present invention can be further surface treated. For example, heat treatment and chemical resistance treatment, chromate treatment, silane coupling treatment, or a combination thereof, and the surface treatment to be carried out can be suitably selected according to the subsequent process.

The heat resistance and chemical resistance treatment are carried out by forming a thin film on a metal foil by sputtering, electroplating or electroless plating, for example, any one of metals such as nickel, tin, zinc, chromium, molybdenum and cobalt or an alloy thereof . In terms of cost, electroplating is preferable. In order to facilitate precipitation of metal ions, a necessary amount of a complexing agent such as citric acid salt, tartaric acid salt, and sulfamic acid may be added.

As the chromate treatment, an aqueous solution containing hexavalent to trivalent chromium ions is used. The chromate treatment may be a simple immersion treatment, but is preferably performed by a negative treatment. Dichromate is preferably carried out in sodium from 0.1 to 70 g / L, pH 1 to 13, bath temperature 15 to 60 ℃, a current density of 0.1 to 5 A / dm ^2, the electrolytic conditions of time of 0.1 to 100 seconds. Chromic acid or potassium dichromate may be used instead of sodium dichromate. The chromate treatment is preferably carried out in an anti-corrosive treatment, whereby the moisture resistance and heat resistance can be further improved.

Examples of the silane coupling agent used for the silane coupling treatment include epoxy functional silanes such as 3-glycidoxypropyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3 Amino functional silanes such as aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane and N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, Olefin functional silanes such as vinyltrimethoxysilane, vinylphenyltrimethoxysilane and vinyltris (2-methoxyethoxy) silane; acrylic functional silanes such as 3-acryloxypropyltrimethoxysilane; Mercaptopropyltrimethoxysilane and other mercapto-functional silanes, and 3-mercaptopropyltrimethoxysilane and other mercapto-functional silanes. These may be used alone, or a plurality of them may be mixed and used.

Such a coupling agent is dissolved in a solvent such as water at a concentration of 0.1 to 15 g / L and is applied to a metal foil at a temperature of from room temperature to 70 ° C, or is adsorbed by electrodeposition. These silane coupling agents condense and bond with the hydroxyl groups of the metal on the surface of the metal foil to form a film. After the silane coupling treatment, stable bonding is formed by heating, ultraviolet irradiation, or the like. The heating is carried out at a temperature of 100 to 200 DEG C for 2 to 60 seconds. The ultraviolet ray irradiation is performed in the range of 200 to 400 nm and 200 to 2500 mJ / cm ² . In addition, the silane coupling treatment is preferably performed on the outermost layer of the copper foil, whereby adhesion between the moisture-proof and insulating resin composition layer and the metal foil can be further improved.

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

(Production of copper foil)

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

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

The basic composition of the copper electrolyte is as follows:

CuSO ₄ .5H ₂ O: 250 to 400 g / L

H ₂ SO ₄ : 80 to 150 g / L

Chloride ions and additives were added to the copper electrolytic solution.

(Example 1)

The copper foil thus prepared was electrolyzed at a current density of 35 A / dm ² for 1 to 5 seconds using the following copper electrolytic solution to form a fine particle layer. A scanning electron microscopy (SEM) image of the surface of the copper foil formed with the fine particle layer according to Example 1 is shown in Fig.

CuSO ₄ .5H ₂ O: 85 g / L

H ₂ SO ₄ : 125 g / L

Fe: 19 g / L

Mo: 1.1 g / L

Co: 8 g / L

(Example 2)

Electroplating was performed on the surface of the copper foil to form a fine particle layer in the same manner as in Example 1, except for the following. An SEM image of the surface of the copper foil with the fine particle layer formed is shown in Fig.

CuSO ₄ .5H ₂ O: 85 g / L

H ₂ SO ₄ : 125 g / L

Fe: 25 g / L

Mo: 1.1 g / L

Co: 8 g / L

(Example 3)

Electroplating was performed on the surface of the copper foil to form a fine particle layer in the same manner as in Example 1, except for the following. An SEM image of the surface of the copper foil on which the fine particle layer is formed is shown in Fig.

CuSO ₄ .5H ₂ O: 85 g / L

H ₂ SO ₄ : 125 g / L

Fe: 19 g / L

Mo: 0.7 g / L

Co: 8 g / L

(Example 4)

Electroplating was performed on the surface of the copper foil to form a fine particle layer in the same manner as in Example 1, except for the following. An SEM image of the surface of the copper foil on which the fine particle layer is formed is shown in Fig.

CuSO ₄ .5H ₂ O: 85 g / L

H ₂ SO ₄ : 125 g / L

Fe: 19 g / L

Mo: 1.1 g / L

Co: 10 g / L

(Comparative Example 1)

Electroplating was performed on the surface of the copper foil to form a fine particle layer in the same manner as in Example 1, except for the following. An SEM image of the surface of the copper foil with the fine particle layer formed is shown in Fig.

CuSO ₄ .5H ₂ O: 70 g / L

H ₂ SO ₄ : 165 g / L

Mo: 0.57 g / L

W: 10 g / L

(Comparative Example 2)

Electroplating was performed on the surface of the copper foil to form a fine particle layer in the same manner as in Example 1, except for the following. An SEM image of the surface of the copper foil on which the fine particle layer is formed is shown in Fig.

CuSO ₄ .5H ₂ O: 70 g / L

H ₂ SO ₄ : 165 g / L

Mn: 1 g / L

(Comparative Example 3)

Electroplating was performed on the surface of the copper foil to form a fine particle layer in the same manner as in Example 1, except for the following. An SEM image of the surface of the copper foil on which the fine particle layer is formed is shown in Fig.

CuSO ₄ .5H ₂ O: 70 g / L

H ₂ SO ₄ : 165 g / L

Ga: 1 g / L

The surface roughness (Rz, Rmax) and peel strength of the surface-treated surfaces of the copper foils of Examples 1 to 4 and Comparative Examples 1 to 3 were measured and shown in Table 1. The surface roughnesses Rz and Rmax were measured in accordance with JIS B 0601-1994. The peel strength was measured by attaching the specimen prepared in the halogen-free prepreg in a size of 10X100 mm and hot-pressing at 210 DEG C for 30 minutes to prepare a peel strength measurement specimen , And the prepared specimens were measured at a speed of 50 mm per minute in the UTM equipment. The lower the surface roughness, the smaller the irregularities.

Rz (占 퐉) Rmax (占 퐉) Peel strength (kgf / cm) Example 1 5.06 6.24 1.31 Example 2 5.43 7.37 1.30 Example 3 5.92 7.27 1.35 Example 4 5.60 7.36 1.32 Comparative Example 1 5.20 7.95 1.16 Comparative Example 2 5.66 9.25 1.15 Comparative Example 3 4.62 7.58 1.10

4 to 7 are surface images of the copper foils of Examples 1 to 4 according to the present invention. Referring to FIG. 4, it can be confirmed that the fine particles are gathered in the acid part of the irregularities on the surface of the copper foil. 5 to 7, it can be seen that the fine particles are densely located in the irregularities on the surface of the copper foil, and are located less in the valley than in the acid.

In contrast, in Figs. 8 to 10, which are the surface images of the copper foils of Comparative Examples 1 to 3, it can be seen that the fine particles are uniformly distributed not only in the irregularities but also in the valleys. In the copper foils of Comparative Examples 1 to 3, the fine particles cover the entire surface of the copper foil.

On the surface of the copper foils of Examples 1 to 4 according to the present invention, the upper fine grains located on the average line of the irregularities exist more than the lower fine grains and the lower fine grains are present in small amounts, It is predicted that the adhesion is high.

Thus, as can be seen from Table 1, the surface roughness of the copper foil of Example 1 is lower than the surface roughness of Comparative Example 1, but the peel strength is higher, so that it can be contacted in subsequent processes, Is high. Particularly, the evaluation result that the peeling strength of the copper foil of Example 1 having a lower surface roughness, which is not the same, is higher than that of Comparative Example 1 can be deduced as a result of the position of the fine particles of Example 1 being concentrated. The copper foil of Examples 2 to 4 had a variation in surface roughness value but was smaller or similar to the surface roughness values of Comparative Examples 1 to 3, but peel strengths were respectively 1.30 kgf / cm or more, Which is higher than the peel strength.

Therefore, when the copper foils of Examples 1 to 4 according to the present invention are used, the adhesiveness with other materials is high at the time of manufacturing a product such as a resin or an active material, so that the defective rate in the process is low and the yield is high. It is possible to form a fine circuit pattern, and the reliability of the product becomes high.

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

Claims (16)

A copper foil in which concave and convex portions are formed on at least one surface and a fine particle layer is formed on the surface, wherein the upper fine particles located on the average line along the average height of the surface are larger than the lower fine particles located below the above average line. The method according to claim 1,
Wherein the ratio of the number of the upper fine particles to the number of the lower fine particles is 80:20 to 100: 0. The method according to claim 1,
Wherein the upper fine particle has a triangle shape connecting the center points. The method according to claim 1,
Wherein the fine particles have a diameter of 1 to 3 占 퐉. The method according to claim 1,
Wherein the fine particles are metal particles containing at least one metal selected from the group consisting of copper (Cu), iron (Fe), molybdenum (Mo), and cobalt (Co). The method according to claim 1,
And a peel strength of 1.28 to 1.33 kgf / cm. The method according to claim 1,
A copper foil having a surface roughness Rz of 5.2 to 6.5 탆. The method according to claim 1,
And a surface roughness Rmax of 6.5 to 7.7 탆. Insulating substrate; And
An electrical part comprising the copper foil according to any one of claims 1 to 8 attached to one surface of the insulating base material. A battery comprising the copper foil according to any one of claims 1 to 8. Preparing a copper foil having unevenness formed on at least one surface thereof; And
Forming a fine particle layer on a surface of the substrate having the unevenness formed thereon and forming a fine particle layer such that the upper fine particle located on the average line along the average height of the surface is larger than the lower fine particle located below the average line; Surface treatment method. The method of claim 11,
The step of forming the fine particle layer may include:
The copper foil is made of copper sulfate; Sulfuric acid; And a metal containing iron (Fe), molybdenum (Mo), and cobalt (Co), and forming a fine particle layer on the surface on which the unevenness is formed. The method of claim 12,
Wherein the content of iron is 10 to 30 g. The method of claim 12,
Wherein the content of the molybdenum is 0.5 to 10 g. The method of claim 12,
Wherein the content of the cobalt is 1 to 15 g. The method of claim 12,
Wherein the electrolysis is performed at 20 to 60 A / dm < ² > for 1 to 5 seconds.

Images