KR100738164B1 - Bronzing-surface-treated copper foil, process for producing the same, and electromagnetic wave shielding conductive mesh for front panel of plasma display utilizing the bronzing-surface-treated copper foil - Google Patents

Abstract

An object of the present invention is to provide a surface-treated copper foil having a browning treatment layer having a uniform color tone without powder dropping, and which does not contain a dissimilar metal which becomes an etching inhibiting factor so as to facilitate etching processing. In order to achieve this object, as a copper foil provided with the browning process surface formed by copper plating performed in multiple steps, the browning surface treatment copper foil whose cross-sectional height of the said browning process surface is 150 nm or less is used. In addition, this browning process surface has the characteristics that the a value in Lab color system is 4.0 or less. This surface-treated copper foil is basically a process a (base plating process), a process b (additional plating process), a process c. (Coating plating process), a process d (finishing plating process), a process e (cleaning and drying) Process).

Description

Browning-surface-treated copper foil, process for producing the same, and electromagnetic wave shielding conductive mesh for front panel of plasma display utilizing the bronzing-surface-treated copper foil}

A surface-treated copper foil having a tea-brownened surface, a manufacturing method of the surface-treated copper foil, and an electromagnetic wave shielding conductive mesh for a front panel of a plasma display using the surface-treated copper foil.

BACKGROUND OF THE INVENTION Conductive meshes for shielding plasma display panels have been transformed from metallized fiber fabrics to conductive meshes. Several methods are established for manufacture of this conductive mesh. One of them is to laminate the surface-treated copper foil on a PET film and to bond it, and to manufacture the photolithographic etching method. The other is a conductive mesh of the surface-treated copper foil single body in which the surface-treated copper foil is etched together with the supporting substrate by a photolithography etching method and then the supporting substrate is peeled off.

In addition, with the recent demand for energy saving, development is underway aiming at a plasma generation signal voltage of 200V to 50V level, and the circuit width of the conductive mesh is thinned in order to cope with the decrease in luminance accompanying the voltage drop. Attempts have been made to reduce the coverage of the front glass panel by the conductive mesh. To this end, attempts have been made to make the thickness of the conductive mesh thin to facilitate the etching process. One of them forms a seed layer which becomes a seed of electroplating by sputtering deposition method on the PET film, and then forms a thin copper layer by electrolytic copper plating, etc., and refines the mesh line width by photolithography etching. Manufacturing has been done.

Even if the conductive mesh is manufactured by any of these methods, the conductive mesh itself is inserted into the front panel and directly visible from the surface through the front glass, so that one side of the surface-treated copper foil processed with the conductive mesh is tea brown to black. It is processed in the dark state of to raise the brightness of transmitted light. Conventionally, this treatment has been dedicated to the surface treatment using a dissimilar metal such as blackening, nickel or cobalt, which is performed to improve the adhesion between the inner layer circuit and the resin layer, which are techniques of a multilayer printed wiring board.

Non-Patent Document 1: Technical Trends of PDP Materials Hitachi Chemical Technical Report No. 33 (1999-7)

Patent Document 1: Japanese Patent Application Laid-Open No. 11-186785

Patent Document 2: Japanese Patent Application Laid-Open No. 2000-31588

Problems to be Solved by the Invention

However, the above-mentioned blackening process had a serious problem. In other words, if a large amount of black oxide of copper is attached to the surface of copper foil, a good black screen can be surely obtained. However, as the amount of adhesion increases, the black oxide of copper formed on the surface of copper foil is more likely to fall out of the black screen, so that a phenomenon of falling powder occurs. The blackened surface is easily damaged, and handling becomes difficult.

When the powder fall occurs, the black oxide dropped out may be mixed in an unnecessary place, or may be a factor that degrades the transparency by dispersing it into the transparent adhesive layer during the transparent treatment for integrating the glass of the front panel.

On the other hand, as a blackening treatment capable of forming a good black screen, general black nickel plating, nickel sulfide plating, cobalt plating, and the like have been studied, but the problem that etching processing from the blackening treatment surface side in the ordinary copper etching process is impossible is difficult. It was happening. In particular, the surface-treated copper foil having a blackened surface in which cobalt and nickel are deposited in large amounts cannot solve the problem of falling powder, and has been an expensive product due to the use of a large amount of expensive nickel or the like.

On the other hand, the manufacturing technology of the plasma display panel has matured, and conventionally, a surface-treated copper foil having a simply good black screen has been required. However, with the advancement of manufacturing technology and management, a high level of blackness of the electromagnetic shielding mesh is not required. Rather, there is a need for an electromagnetic shielding mesh having a mesh pattern having a high aperture ratio in which etching processing is easy and the light transmittance is stable at low cost.

Therefore, a problem arises in that the copper foil with the cobalt black plating film currently distributed on the market is difficult to etch from the cobalt layer using copper etchant. It has been an attempt.

Certainly, considering that the etching is easy while satisfying the low-cost condition, it is expected to supply to the market in a brown-brown state by reducing the adhesion amount of cobalt or the like without blackening the surface of the surface-treated copper foil. However, there is no change in the use of dissimilar metals such as cobalt or nickel, so that it is impossible to completely eliminate the difference in etching performance with the copper foil which does not contain dissimilar metals, which causes a large load of etching waste treatment and inhibits etching.

Moreover, the drawback of the surface-treated copper foil which has the conventional tea-brown surface was the point that the color of the tea-brown surface is not uniform, and a stain arises on the whole surface. That is, since the browning-brown processing in the same plane is not uniformized, it is causing the deviation of the cross-sectional shape of the mesh obtained by etching, when speaking to carry out etching processing from the said brown-brown surface strictly. In addition, the tea-brown surface was matt and easily damaged by rubbing lightly on its surface.

Therefore, there is a need in the market for a surface-treated copper foil for a plasma shielding panel of a plasma display panel having a tea browning treatment layer having a uniform tea brown color and not containing a dissimilar metal that is an etch inhibiting factor so as to facilitate etching processing. Came.

Means to solve the problem

Here, the inventors of the present invention have repeatedly studied, and when the surface-treated copper foil is manufactured by the manufacturing method as described below, it is possible to obtain a surface-treated copper foil which does not include a dissimilar metal which is conventionally a factor of inhibiting etching. will be.

<Brownish surface treatment copper foil>

The browned surface-treated copper foil described below is a copper foil provided with the browning process surface formed by copper plating performed in multiple steps like the manufacturing method mentioned later. In the present invention, the term "copper plating performed in multiple stages" refers to a copper plating process employing two or more plating treatment operations rather than being formed by one plating treatment operation. Here, as the base copper foil, any of electrolytic copper foil or rolled copper foil can be used. And when electrolytic copper foil is used, it becomes possible to selectively use either the glossy surface or the rough surface.

The 1st characteristic with the surface-treated copper foil which concerns on this invention is that the surface shape of the browning process surface is not very coarse, and the cross-sectional height which the said browning process surface has is 150 nm or less, The 1st characteristic is a 1st characteristic. That is, it can be said that it is the browning process surface which is very smooth and has a gloss. However, in order to avoid misunderstanding, it is specified that there is a deviation within the normal manufacturing process range, and the cross-sectional height at all positions does not necessarily need to be 150 nm or less, and 150 to the degree that reflects the deviation of the manufacturing process. Naturally, the cross-sectional height exceeding nm may exist. The FIB observation image observed in the cross section using the FIB analysis apparatus in order to measure the cross-sectional height of the browning process surface 2 of the surface-treated copper foil 1 which concerns on this invention is shown in FIG. In FIG. 1, the browning process surface was formed in the glossy surface of the electrolytic copper foil. On the other hand, this FIB observation image is observed at a 60 ° angle with respect to the observed surface.

As can be seen from FIG. 1, it can be seen that certain irregularities exist in the cross section of the browning surface, and when monitoring such irregularities, it is common to use a stylus type surface roughness measuring system. However, as can be seen from the scale of FIG. 1, it is considered that the surface roughness measurement system is an unevenness at a level at which accurate roughness measurement is impossible. Therefore, in the present invention, the maximum difference between the floor and the valley in the field of view on the FIB observation is set to the 'cross section height' as a value corresponding to Rmax when measured by the surface roughness measurement system. In Fig. 1, the area indicated by 'd' becomes the cross-sectional height of Fig. 1 and can be determined as about 80 nm. In addition, in FIG. 1, the browning process surface 2 is formed along the shape of the surface of copper foil with a very uniform thickness, maintains the state in which it fully adhered to the copper foil surface of the base, and the browning process surface 2 is No defects such as glass are found, and no powder is expected to fall.

On the other hand, when FIB observation is carried out from the cross section similarly to the above-mentioned browning process surface of the copper foil provided with the conventional browning process surface, it will result as shown in FIG. That is, it turns out that the shape which comprises the browning process surface grows in resin shape, and is in the state which protruded considerably from the copper foil of a base. Therefore, when the cross-sectional height d at this time is measured, it turns out that it is about 180 nm, and it becomes a very rough surface. In addition, the browning surface having such a dendritic shape may be said to be a surface that is susceptible to breakage of the dendritic region, and that the fall of powder may occur when the broken fragments fall off, and the browning surface may be viewed by eye. It is thought that it is causing color unevenness.

It can be seen that the surface-treated copper foil according to the present invention described above has a very smooth surface from the FIB cross-sectional view of FIG. 1. However, although it is a glossy browning treatment, it does not have a gloss enough to diffusely reflect the light received by the browning surface. It will be 4.0 or less. As described here with 4.0 or less, it also includes the matte state which shows the negative value as glossiness. Such a matte-treated surface in a matte state is likely to be formed when the roughened surface of the electrolytic copper foil is subjected to a browning treatment.

Whether the surface of the browning surface is in a matte state is more preferable to use glossiness than the Lab color system. However, the glossiness of the browned surface according to the present invention should be classified according to the type of the base forming the browned surface. First, when the said browning process surface forms the said browning process surface in the gloss surface of electrolytic copper foil or the surface of a rolled copper foil, it is preferable that glossiness [Gs (60 degrees)] is 10 or less. This is because when the glossiness is 10 or more, it becomes a so-called black light state and the metallic luster becomes noticeable.

And it is preferable that glossiness [Gs (60 degrees)] is 3 or less for the said browning process surface at the time of selecting the base material with an unevenness | corrugation like the rough surface of an electrolytic copper foil. This is because when the glossiness is 3 or more, it is highly likely to be a surface that is likely to cause powder fall due to the relationship with the burn-up plating constituting the browned surface.

Moreover, it is also preferable to provide an antirust process layer in the said browning process surface. It is because long-term storage property of the surface-treated copper foil which concerns on this invention can be ensured. If the antirust process layer does not cause discoloration of the browning process layer and can be easily dissolved by a copper etching solution, inorganic antirust agents such as zinc and brass, organic antirust agents such as benzotriazole and imidazole, etc. Etc. can be used.

<The manufacturing method of the surface-treated copper foil provided with the browning process surface>

(Manufacturing method 1 of the surface-treated copper foil provided with the browning process surface)

The basic manufacturing method of the surface-treated copper foil provided with the browning process surface which concerns on this invention is equipped with each process of the following process a-process e. The copper plating forming the browning surface is not formed by one plating operation but is divided into a plurality of plating processes, and the copper plating is performed in multiple steps. The process will be described below.

Process a: The first plating treatment (hereinafter, referred to as "base plating treatment") for making the surface of copper foil brown using copper sulfate type plating solution as the burn-up plating condition is called a basic plating treatment process in this invention.

Here, the copper foil which is to be plated in the basic plating step may be subjected to rough treatment or not. This roughening process is performed in order to obtain favorable adhesiveness with the base material to be bonded, etc., and is roughened intentionally by a method such as attaching fine copper particles or attaching a copper oxide that appears black.

In this basic plating process, plating process is performed on what is called the burn-in plating condition of copper. However, the burn-up plating performed in this basic plating process is for forming the nucleus for forming some unevenness | corrugation on the copper foil surface, and even if it observes the copper foil surface after a basic plating process with a scanning electron microscope clearly in a rough state, It is invisible.

Accordingly, the amount of burnt plating electrodeposited in this basic plating step is about 300 mg / m 2 to 600 mg / m 2 as the converted thickness (hereinafter, simply referred to as “converted thickness”) when plating is performed on a completely smooth and flat plane. It should be electrodeposition amount. If it is less than 300 mg / m <2>, it cannot be said that the nucleus for sufficient roughening process was formed, and even if it performs the further plating process mentioned later, a favorable browning process surface cannot be formed. On the other hand, when it exceeds 600 mg / m <2>, when the further plating process mentioned later is performed, a roughening process will progress too much and the browning process surface which is easy to fall powder is formed.

The conditions of the burn-in plating here are not specifically limited, It is decided in consideration of the characteristic of a production line. For example, if a copper sulfate-based solution is used, the concentration is 5 to 20 g / l copper, 50 to 200 g / l sulfuric acid, and other additives as necessary (α-naphthoquinoline, dextrin, glue, thiourea, etc.), liquid temperature 15 It is set as the conditions of -40 degreeC and the current density of 10-50 A / dm <2>.

Process b: This process is an additional plating process process which performs one or more additional plating processes using the copper sulfate type plating solution on the surface of the base-plated copper foil as burn-in plating conditions. The burn-in plating conditions in this additional plating process may employ the same conditions as in step a. However, since a nucleus is formed on the surface of the copper foil in step a. It is preferable to prevent the concentration of currents in the core of the lower surface by preventing the abnormality of unnecessary abnormality. That is, with respect to the current density Ia used when performing the burn-up plating in the step a, the current density Ib used when the burn-in plating in the step b is made to have a current density of 50% or less of Ia.

Here, it is also possible to perform 2 or more times of plating processes, as it says "one or more additional plating processes." However, at this time, the plated surface formed by the basic plating treatment and the additional plating treatment does not form a rough rough state visible, but can uniformly cover the surface to be plated and create a light roughness to some extent. do. Therefore, it should be noted that it is necessary to control the total current and the total electrolysis time of the basic plating process and the additional plating process to produce a light roughness state.

Based on the plating amount in the above-mentioned basic plating process, the appropriate electrodeposition amount in the additional plating process should be an electrodeposition amount of about 50 mg / m 2 to 300 mg / m 2 as converted thickness. In the case of less than 50 mg / m <2>, an appropriate uneven | corrugated shape cannot be provided to the surface nucleated in process a., And a favorable browning process surface cannot be obtained. On the other hand, when it exceeds 300 mg / m <2>, the browning process surface in which the nucleus growth formed in the process a is excessively excessive and powder falls easily is formed.

Process c: This process is a coating plating process process which performs a plating process on smooth plating conditions using a copper plating solution to the copper foil surface which baked-baked by process a and process b. The coating plating step is a plating treatment for smoothing the surface roughened in the steps a and b, and a step for uniformly depositing copper to cover the baked plated surface. Therefore, it is possible here to use all the copper electrolytes which can smoothly plate copper. This smooth plating condition is not specifically limited, It decides in consideration of the characteristic of a production line. For example, in the case of using a copper sulfate solution, the concentration is set to 50 to 80 g / l copper, 50 to 150 g / l sulfuric acid, 40 to 50 ° C liquid temperature, and 10 to 50 A / dm 2 current density.

However, the electrolytic time should be an electrodeposition amount of about 5 g / m 2 to about 10 g / m 2 as the converted thickness at the time of plating in a completely smooth and flat plane so that the shape roughened by the burn plating is not excessively smooth. If it is less than 5 g / m 2, the effect of smoothing the surface roughened in steps a and b cannot be obtained. On the other hand, when it exceeds 10 g / m <2>, the surface roughened by the process a and the process b becomes excessively smooth, and the color of a browning process surface increases metal gloss.

Process d: This process is a plating process for finishing copper foil surface brown using the plating conditions which burned the copper plating solution to the surface in which process c was completed and the smooth plating process was performed (henceforth "finish plating process.") It is the finish plating process process which performs. The difference between the burn-in plating in this step, the above-described basic plating step and the additional plating step is that the rough treatment is performed using very fine copper particles (hereinafter, referred to as 'micro copper particles') in this step.

In general, a copper electrolyte containing arsenic is used to form these ultrafine copper particles. As an example of such electrolytic conditions, as a copper sulfate solution, the concentration was set to conditions of copper 10 g / l, sulfuric acid 100 g / l, arsenic 1.5 g / l, liquid temperature 38 ° C., and current density of 30 A / dm 2. However, in the present invention, as an environmental problem arises recently, a copper electrolyte solution having 9-phenylacridin added in place of arsenic as an additive having a lower likelihood of affecting the human body will be used. 9-phenylacridine plays the same role as arsenic in the copper electrolytic field to enable the graining effect and uniform electrodeposition of the fine copper particles precipitated. That is, as a copper electrolyte for forming the ultrafine copper particles to which 9-phenylacridine is added, the concentration is 5 to 15 g / l copper, 40 to 100 g / l free sulfuric acid, and 50 to 300 mg / 9-phenylacridine. l, chlorine concentration 20ppm-32ppm, liquid temperature 30-40 degreeC, current density 20-40A / dm <2> become the range which enables very stable electrolytic operation. More preferably, copper 10-15 g / l, free sulfuric acid 40-70 g / l, 9-phenylacridine 100-200 mg / l, chlorine concentration 25 ppm-30 ppm, liquid temperature 30-40 degreeC, current density 20-40 A / dm 2 range. This range is most excellent in operational stability and solution stability as a plating liquid, and the production yield of the surface-treated copper foil which concerns on this invention becomes high.

Process e: This process is a washing | cleaning and drying process which washes and dries after completion | finish of each process mentioned above, and sets it as a brownish surface-treated copper foil. Washing and drying may be carried out according to a predetermined technique, and there are no special conditions. It should be noted that washing with water here simply means final washing, and it is noted that water washing, which can be considered within a common sense, is appropriately prepared so as not to bring the solution of the pre-process to the post-process between each step.

 (Manufacturing method 2 of the surface-treated copper foil provided with the browning process surface)

This manufacturing method is a manufacturing method of the browning surface-treated copper foil provided with each process of process a-process f shown below.

Process a: The basic plating process which performs the initial plating process (henceforth a "base plating process") to make the surface of copper foil brown using a copper sulfate type plating solution as a burn-in plating condition.

Process b: The further plating process which performs one or more additional plating processes using the copper sulfate type plating solution on the surface of the copper foil which carried out the base plating process by the burning plating condition.

Process c: The coating plating process process of performing a plating process on smooth plating conditions using the copper sulfate type plating solution to the copper foil surface which baked-baked by the process a and the process b.

Step d: A plating treatment (hereinafter referred to as a 'finishing plating treatment') for finishing the copper foil surface on a brown surface using a copper sulfate plating solution as a burning plating condition on the surface where the process c is completed and the smooth plating treatment was performed. Finishing plating treatment process.

Process e: The antirust process which performs a rust prevention process on the surface of the copper foil with which browning process was completed by the above process.

Process f: The washing | cleaning and drying process of washing and drying after completion | finish of each above-mentioned process, and using it as a brownish surface-treated copper foil.

As can be seen from the above process, the antirust treatment layer is added to the manufacturing method 1. Therefore, only the antirust treatment process will be described in order to avoid duplicate explanation.

In the rust-preventing treatment step, a treatment is performed to prevent discoloration of the browning treatment surface, to facilitate etching removal in the copper etching solution, and to prevent oxidative corrosion of the surface of the surface-treated copper foil. The method used for the rust prevention treatment may be any organic rust preventive agent using benzotriazole, imidazole or the like, or inorganic rust preventive agent using zinc, chromate or zinc alloy. What is necessary is just to select the rust prevention according to the purpose of use of a surface-treated copper foil. In the case of organic rust prevention, it becomes possible to employ techniques such as dip coating, showering coating, and electrodeposition of the organic rust inhibitor. In the case of inorganic rust prevention, it is possible to use a method of depositing the rust-preventing element on the surface of the surface-treated copper foil by electrolysis, and other so-called substitutional precipitation. For example, if zinc antirust treatment is carried out, it is possible to use a zinc pyrophosphate plating bath, a zinc cyanide plating bath, a zinc sulfate plating bath and the like. For example, if the zinc pyrophosphate plating bath has a concentration of 5 to 30 g / l zinc, 50 to 500 g / l potassium pyrophosphate, 20 to 50 ° C liquid temperature, pH 9 to 12, and current density of 0.3 to 10 A / dm 2 And the like.

In addition, it is preferable to perform plating treatment using a zinc-nickel alloy plating solution or a zinc-cobalt alloy plating solution as the inorganic rust preventive effect on the color tone of the brown-treated surface of the surface-treated copper foil according to the present invention. First, zinc-nickel alloy plating will be described. The zinc-nickel alloy plating solution used herein is not particularly limited, but examples thereof include nickel concentrations of 1 to 2.5 g / l using nickel sulfate and zinc concentrations of 0.1 to 1 g / l using zinc pyrophosphate and potassium pyrophosphate. The conditions of 50-500 g / l, liquid temperature 20-50 degreeC, pH 8-11, and current density of 0.3-10 A / dm <2> are employ | adopted.

Next, zinc-cobalt alloy plating is demonstrated. The zinc-cobalt alloy plating solution used herein is not particularly limited, but for example, the cobalt concentration is 1 to 2.5 g / l using cobalt sulfate, the zinc concentration is 0.1 to 1 g / l using zinc pyrophosphate, and the pyroic acid. Potassium 50-500 g / l, liquid temperature 20-50 degreeC, pH 8-11, current density of 0.3-10 A / dm <2>, etc. are employ | adopted. The antirust process layer which combined this zinc-cobalt alloy plating and the chromate treatment mentioned later shows especially excellent corrosion resistance performance.

In order to enhance the rust prevention effect, after forming a zinc-nickel alloy layer, a zinc-cobalt alloy layer, or the like on the surface of the surface-treated copper foil, it is possible to obtain more excellent corrosion resistance. That is, what is necessary is just to perform a chromate process after formation of the above-mentioned antirust process layer. In this chromate treatment process, you may employ | adopt any method of the substitution process which contacts a chromate solution, or the electrolytic chromate process which electrolyzes in a chromate solution and forms a chromate film. Moreover, also about the chromate solution used here, it is possible to use the thing of the range used by a conventional method. And it washes and dries after that, and obtains the surface-treated copper foil provided with the browning process surface.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the cross-sectional layer structure of the surface-treated copper foil provided with the browning process surface.

It is a figure which shows typically the cross-sectional layer structure of the surface-treated copper foil provided with the browning process surface.

[Description of the code]

1. Surface treatment copper foil

2. Browned surface

The surface-treated copper foil with the browning surface according to the present invention described above has a good brown color with no powder falling off from the browning surface, and is very uniform and without color unevenness. The process allows etching removal. Therefore, it is possible to easily process to arbitrary shapes using the process of manufacturing a printed wiring board. Considering this point, it can be said that it is optimal for the use of the electromagnetic shielding conductive mesh inserted into the front panel of the plasma display panel.

Moreover, the manufacturing method of the surface-treated copper foil which concerns on this invention makes it possible to form a browning process surface at high efficiency on the surface of copper foil by employ | adopting the multi-step copper burn-up plating method which is not conventional, and the surface treatment provided with the browning process surface. Variation of the hue of copper foil can be made very small.

Below, the result of having manufactured the surface-treated copper foil provided with the browning process surface mentioned above, and manufactured the electromagnetic wave shielding conductive mesh using a copper etching liquid.

Example 1

In this embodiment, the electrolytic copper foil which has not been roughened was subjected to browning treatment on its glossy surface to prepare a surface treated copper foil, and to test the electromagnetic shielding conductive mesh shape by an etching method to confirm the etching performance.

In the present embodiment, a very low profile copper foil having a nominal thickness of 10 µm obtained by electrolyzing a copper sulfate solution was used. The electrolytic copper foil was immersed in this solution for 30 seconds using a sulfuric acid concentration of 150 g / l and a dilute sulfuric acid solution having a liquid temperature of 30 ° C. to clean the surface. The process will be described below.

<Manufacture of surface-treated copper foil>

Step a: Here, the surface of the copper foil is browned using the copper sulfate-based plating solution under the burn-in plating condition with respect to the glossy surface (Ra = 0.22 µm, Rz = 1.54 µm) of the berry low profile copper foil which is not subjected to the roughening treatment. Basic plating treatment was performed.

The basic plating process conditions used at this time were performed by electrolyzing as copper sulfate solution on the copper plating condition of 18 g / l copper concentration, 100 g / l free sulfuric acid concentration, 25 degreeC of liquid temperature, and 10 A / dm <2> of current density (Ia). As a result, the burn-up plating performed in this basic plating process only formed the nucleus for forming some unevenness | corrugation on the copper foil surface, and was the electrodeposition amount of 300 mg / m <2> of conversion thickness.

Process b: In this additional plating treatment step, one plating treatment was performed on the surface of the copper foil subjected to the basic plating treatment using a copper sulfate plating solution as the burn-in plating condition. At this time, the copper plating solution at the same concentration and liquid temperature as in step a. Was used, but the current density (Ib) employed in the burn-in plating was 1.5 A / dm 2, which was 15% of Ia. In step a., Current concentration on the nucleus formed on the surface of the copper foil was prevented to prevent unnecessary abnormal precipitation. The electrodeposition amount in this additional plating process was made into the electrodeposition amount of 50 mg / m <2> as conversion thickness.

Process c: In this coating plating process, the plating process was performed on the smooth plating conditions using the copper plating solution to the copper foil surface which baked-baked by the process a and the process b. In this coating plating process, the copper sulfate solution was electrolyzed under a smooth plating condition of a copper concentration of 65 g / l, a free sulfuric acid concentration of 150 g / l, a liquid temperature of 45 ° C., and a current density of 15 A / dm 2. In this way, the surface roughened by the process a and the process b was smoothed. The conversion thickness of the smooth plating at this time was 4 g / m <2>.

Process d: In this finishing plating process, the process c is completed and the plating process for finishing the copper foil surface to brown color is performed by using the copper plating solution as the burning plating condition on the surface where the smooth plating process is performed, thereby adhering the ultrafine copper particles. It is.

The following copper sulfate solution which added 9-phenylacridine for formation of this ultrafine copper particle is used. As this copper electrolyte solution and electrolytic conditions, copper concentration was 13 g / l, 50 g / l of free sulfuric acid, 150 mg / l of 9-phenylacridine, 28 ppm of chlorine concentration, and 35 degreeC of liquid temperature, and the current density of 24 A / dm <2> was used. In addition, the electrodeposition amount in this finishing plating process was made into the electrodeposition amount of 300 mg / m <2> as conversion thickness.

Process e: In this washing and drying process, after completion of the above-mentioned step d., The pure water is sufficiently showered and washed, and condensed for 4 seconds in a drying furnace with an atmospheric temperature of 150 ° C. with an electric heater to blow out moisture, thereby producing a very good color tone. The surface-treated copper foil provided with the browning process surface of was obtained. On the other hand, it is not limited to the water washing here, and between each process, the washing process between processes was appropriately provided so that the solution of a previous process may not be carried to a post process.

<Physical Properties of Surface-treated Copper Foil>

When the cross section of the surface-treated copper foil provided with the browning process surface obtained through the above process was observed with the FIB apparatus, the cross section as shown in FIG. 1 can be obtained, and the cross-sectional height (d) of the said browning process surface is 80 nm. The a value in the Lab colorimetric system of the browning treatment surface was 3.5 and the glossiness [Gs (60 °)] was 2.8. Moreover, it was not able to confirm powder fall-off in the tape test by sticking and peeling an adhesive tape on a browning process surface.

<Production of electromagnetic shielding mesh for plasma display>

The dry film which becomes an etching resist was stuck to both surfaces of the surface-treated copper foil obtained as mentioned above. The conductive mask pattern having a mesh pitch of 200 mu m, a mesh line width of 10 mu m, a mesh bias angle of 45 DEG C, and a mesh electrode portion around the superimposed mask film for starting the electromagnetic wave shielding conductive mesh was laminated only to the dry film on the browning side. . At this time, the entire surface of the etching resist layer on the opposite side was also exposed to ultraviolet rays to prevent removal by subsequent development. Thereafter, the solution was developed using an alkali solution to form an etching pattern.

Then, using the iron chloride etching solution, which is a copper etching solution, copper etching was performed on the side of the browning treatment surface, and then the etching resist layer was peeled off to prepare an electromagnetic shielding conductive mesh. As a result, very good etching was performed without etching residues.

Example 2

In this example, step d. And step e. The point which provided the antirust process in between is only different from Example 1. Therefore, step a, step b, step c, and step d are the same as those in Example 1, and only the antirust treatment step of step e.

Process e: In this antirust process, plating is performed using a zinc-nickel alloy plating solution to form a zinc-nickel alloy layer on both surfaces. The zinc-nickel alloy layer has nickel concentration of 2.0g / l using nickel sulfate, zinc concentration of 0.5g / l using zinc pyrophosphate, potassium pyrophosphate 250g / l, liquid temperature 35 ° C, pH 10, current density 5A Electrolysis was carried out for 5 seconds under the condition of / dm &lt; 2 &gt; to uniformly and smoothly deposit on both surfaces.

Step f: This washing and drying step corresponds to step e. Of Example 1, and after completion of step e. Described above, the resultant is sufficiently washed with heat and dried to obtain a surface-treated copper foil having a browning surface. Same as Example 1.

<Physical Properties of Surface-treated Copper Foil>

As a result of observing the cross section of the surface-treated copper foil provided with the browning process surface obtained through the above process with a FIB apparatus, the cross section as shown in FIG. 1 can be obtained, The cross-sectional height of the said browning process surface is 85 nm, The said browning process surface The a value in the Lab color system of was 3.6 and the glossiness [Gs (60 °)] was 2.6. Moreover, it was not able to confirm powder fall-off in the tape test by sticking and peeling an adhesive tape on a browning process surface.

<Production of electromagnetic shielding mesh for plasma display>

Similarly to Example 1, the electromagnetic wave shielding conductive mesh was started using the obtained surface-treated copper foil. As a result, even if the rust-prevented layer existed, there was no problem in the etching operation and there was no etching residue, and very good etching was performed.

Example 3

Although Example 1 formed the browning process surface at the gloss surface of the berry low profile copper foil of the nominal-thickness 10 micrometers of electrolytic copper foil, in this embodiment, the surface-treated copper foil which provided the browning process surface at the rough surface side was manufactured. First, similarly to Example 1, this electrolytic copper foil was immersed in this solution for 30 seconds using the sulfuric acid concentration 150g / l and the dilute sulfuric acid solution of 30 degreeC of liquid temperature, and the surface was cleaned. The process will be described below.

<Manufacture of surface-treated copper foil>

Step a : Herein, the surface of the copper foil is browned using the copper sulfate plating solution as the burn-in plating condition with respect to the rough surface (Ra = 0.35 µm, Rz = 2.32 µm) of the berry low profile copper foil which is not subjected to the rough treatment. Basic plating treatment was performed. The surface roughness of the rough surface of this berry low profile copper foil was made into the surface of the profile so low that even a gloss surface did not interfere. Hereinafter, the same process a (base plating process) as a Example 1, process b (additional plating process), process c (coating plating process), process d (finishing plating process), process e (washing and drying process) ) To obtain a surface-treated copper foil having a browning surface.

<Physical Properties of Surface-treated Copper Foil>

When the cross section of the surface-treated copper foil provided with the browning process surface obtained through the above process was observed with the FIB apparatus, the cross section as shown in FIG. 1 can be obtained, The cross-sectional height of the said browning process surface is 75 nm, The said browning process The a value in the Lab color system of cotton was 3.6, and glossiness [Gs (60 degrees)] was 1.2. Moreover, it was not able to confirm powder fall-off in the tape test by sticking and peeling an adhesive tape on a browning process surface.

<Production of electromagnetic shielding mesh for plasma display>

Similarly to Example 1, the electromagnetic wave shielding conductive mesh was started using the obtained surface-treated copper foil. As a result, even if the browning process surface was formed in the rough surface side of copper foil, etching operation was satisfactory and there was no etching residue, and very favorable etching was performed.

Example 4

Although the browning process surface was formed in the gloss surface of the berry low profile copper foil of the nominal-thickness 10 micrometers whose Example 2 is electrolytic copper foil, in this embodiment, the surface-treated copper foil in which the browning process surface was formed in the rough surface side was manufactured. First, the surface of the electrolytic copper foil was cleaned using the procedure of Example 1 similarly to Example 2. The process will be described below.

<Manufacture of surface-treated copper foil>

Here, in the same manner as in Example 1, for the rough surface (Ra = 0.35 µm, Rz = 2.32 µm) of the berry low profile copper foil which was not subjected to the rough treatment as in Example 3, step a (base plating treatment step), The process b (additional plating process process), the process c (coating plating process process), and the process d (finishing plating process process) were performed. And unlike Example 3, the surface-treated copper foil provided with the browning process surface was obtained through adding process e (rustproof process) and process f. (Cleaning and drying process). In the step e (antirust treatment step) at this time, a zinc-nickel alloy layer is formed in the same order as in Example 2. Therefore, since the above process is demonstrated in the said Example, overlapping description is abbreviate | omitted.

<Physical Properties of Surface-treated Copper Foil>

As a result of observing the cross section of the surface-treated copper foil provided with the browning process surface obtained by the above process with a FIB apparatus, the cross section as shown in FIG. 1 was obtained, The cross-sectional height of the said browning process surface is 74 nm, The a value in the Lab colorimeter was 3.8 and the glossiness [Gs (60 °)] was 1.5. Moreover, it was not able to confirm powder fall-off in the tape test by sticking and peeling an adhesive tape on a browning process surface.

<Production of electromagnetic shielding mesh for plasma display>

Similarly to Example 1, the electromagnetic wave shielding conductive mesh was started using the obtained surface-treated copper foil. As a result, even if the rust-prevented layer existed, there was no problem in the etching operation and there was no etching residue, and very good etching was performed.

Comparative Example 1

In this comparative example, the copper concentration of the copper sulfate solution used in step d. Of Example 1 was lowered, thereby deviating from the optimum conditions, and adhesion formation of the ultra fine copper particles was performed. Therefore, only the process d. Will be described.

Process d: In this finishing plating process, the copper concentration of the copper sulfate solution which added 9-phenylacridine used in Example 1 was 8 g / l. In addition, the electrodeposition amount in this finishing plating process was made into the electrodeposition amount of 300 mg / m <2> as conversion thickness similarly to Example 1.

<Physical Properties of Surface-treated Copper Foil>

As a result of observing the cross section of the surface-treated copper foil provided with the browning process surface obtained by the above process with a FIB apparatus, the cross section as shown in FIG. 2 was obtained, and the cross-sectional height (d) of the said browning process surface is 180 nm, and the said browning process is carried out. The a value in the Lab color system of the treated surface was 3.6 and the glossiness [Gs (60 °)] was 2.6. As can be seen from the comparison between Fig. 1 and Fig. 2 when compared with the above embodiment, it can be seen that the surface of the processing nucleus is abnormally grown by the finish plating treatment and the powder is dropped. In addition, color unevenness in the same plane of the browned surface is noticeable. In addition, it was confirmed that the powder was dropped in the tape test by attaching and detaching the adhesive tape to the browned surface.

<Production of electromagnetic shielding mesh for plasma display>

Similarly to Example 1, the electromagnetic wave shielding conductive mesh was started using the obtained surface-treated copper foil. As a result, although the etching operation did not interfere, the browning process surface of the surface-treated copper foil obtained by this comparative example was easy to be damaged by friction at the time of handling, and it was difficult to maintain the original browning process surface until completion of an etching process.

The surface-treated copper foil provided with the browning process surface which concerns on this invention is equipped with the browning process surface which is excellent in the flaw resistance without color unevenness, there is no fall of the powder in the blackening process surface, and it uses the normal copper etching liquid Etching is possible and a high quality black mask can be formed by using the electromagnetic shielding conductive mesh of the front panel of the plasma display panel. In addition, by supplying it as the surface-treated copper foil provided with the browning process surface, the blackening process process in a manufacturing process of a front panel can be omitted.

In addition, by adopting a multi-step copper-plated plating method in the formation of the browning-treated surface and employing a manufacturing method of performing smooth plating and finish-baked plating, the surface-treated copper foil according to the present invention can be produced in high yield, thereby reducing production costs. This is possible.

Claims (16)

A copper foil provided with the browning process surface formed by performing the tanning plating of copper in multiple steps, The cross-sectional height of the said browning process surface is 150 nm or less, The browning surface-treated copper foil characterized by the above-mentioned. The method of claim 1, The said browning process surface is the browning surface-treated copper foil whose a value is 4.0 or less in Lab color system. The method of claim 1, The brownish surface-treated copper foil provided with the antirust process layer in the said browning process surface. The method of claim 1, The said browning process surface formed the said browning process surface on the gloss surface of electrolytic copper foil or the surface of a rolled copper foil, and has a glossiness [Gs (60 degrees)] of 10 or less. The method of claim 1, The said browning process surface formed the said browning process surface in the rough surface of an electrolytic copper foil, The glossiness [Gs (60 degrees)] is 3 or less browning surface-treated copper foil. A manufacturing method of browning surface-treated copper foil as a manufacturing method of browning surface-treated copper foil, Comprising: The process of the following process a-process e is provided. Process a: The basic plating process which performs the initial plating process (henceforth a "basal plating process") to make the surface of copper foil brown using a copper sulfate type plating solution as a burning plating condition. Step b: an additional plating treatment step of performing one or more additional plating treatments on the surface of the copper foil subjected to the basic plating treatment using a copper sulfate plating solution as the burning plating condition; Process c: The coating plating process process of performing a plating process on smooth plating conditions using the copper sulfate type plating solution to the copper foil surface which baked-baked by the process a and the process b. Process d: The plating process (henceforth a "finishing plating process") is performed to finish the copper foil surface brown using the copper sulfate type plating solution as the burn-in plating condition on the surface in which process c was completed and the smooth plating process was performed. Finishing plating treatment process. Process e: The washing | cleaning and drying process of washing and drying after completion | finish of each process mentioned above and washing with water and drying and finishing with browning surface treatment copper foil. The method of claim 6, A current density (Ib) employed when performing a baked plating in step b with respect to the current density (Ia) used when performing the burn plating in step a is a current density of 50% or less of Ia. The method of claim 6, The copper plating solution used for the burn-up plating in step d has a copper concentration of 5 to 15 g / l, free sulfuric acid 40 g / l to 100 g / l, 9-phenylacridine 50 to 300 mg / l, and a chlorine concentration of 20 to A manufacturing method of 32 ppm brownish surface-treated copper foil. A manufacturing method of browning surface-treated copper foil as a manufacturing method of browning surface-treated copper foil, Comprising: Each process of the following process a-process f is provided. Process a: The basic plating process which performs the initial plating process (henceforth a "basal plating process") to make the surface of copper foil brown using a copper sulfate type plating solution as a burning plating condition. Step b: an additional plating treatment step of performing one or more additional plating treatments on the surface of the copper foil subjected to the basic plating treatment using a copper sulfate plating solution as the burning plating condition; Process c: The coating plating process process of performing a plating process on smooth plating conditions using the copper sulfate type plating solution to the copper foil surface which baked-baked by the process a and the process b. Process d: The copper sulfate plating solution is burnt on the surface where the process c was completed and the smooth plating process was performed, and the plating process (hereinafter referred to as 'finishing plating process') for finishing the copper foil surface in brown using plating conditions. Finish plating treatment process. Process e: The antirust process which performs a rust prevention process on the surface of the copper foil with which browning process was completed by the above process. Process f: After completion | finish of each process mentioned above, the washing | cleaning and drying process of washing with water and drying and finishing with browning surface treatment copper foil. The method of claim 9, A current density (Ib) employed when performing a baked plating in step b with respect to the current density (Ia) used when performing the burn plating in step a is a current density of 50% or less of Ia. The method of claim 9, The copper plating solution used for the burn-up plating in step d has a copper concentration of 5 to 15 g / l, free sulfuric acid 40 to 100 g / l, 9-phenylacridine 50 to 300 mg / l, and a chlorine concentration of 20 to 32 ppm. Manufacturing method of browning surface-treated copper foil. The electromagnetic wave shielding conductive mesh for front panels of a plasma display using the brownish surface-treated copper foil of Claim 1. Electromagnetic shielding conductive mesh for a front panel of a plasma display using the brownish surface-treated copper foil of Claim 2. The electromagnetic wave shielding conductive mesh for front panels of a plasma display using the brownish surface-treated copper foil of Claim 3. The electromagnetic wave shielding conductive mesh for front panels of a plasma display using the brownish surface-treated copper foil of Claim 4. The electromagnetic wave shielding conductive mesh for front panels of a plasma display using the brownish surface-treated copper foil of Claim 5.

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