KR20070004658A - Surface-treated copper foil having grayed surface, process for producing the same and electromagnetic wave shielding conductive mesh for front panel of plasma display wherein use is made of the surface-treated copper foil - Google Patents

Abstract

A surface-treated copper foil that exhibits an excellent gray and can be worked by the common copper etching process; and an electromagnetic wave shielding conductive mesh for PDP produced with the use of the surface-treated copper foil. There is provided, for example, a surface-treated copper foil furnished on its one major surface side with a surface having undergone graying treatment, characterized in that the surface having undergone graying treatment results from formation of a cobalt sulfate plating layer on a rough surface of copper foil layer and further formation of a layer treated for corrosion prevention. Moreover, there is provided, for example, a process for producing the surface-treated copper foil, comprising electrolyzing a cobalt plating solution containing cobalt sulfate (heptahydrate) at a given current density onto a rough surface of electrolytic copper foil, etc. to thereby form a layer treated for corrosion prevention and performing water washing and drying thereof. ® KIPO & WIPO 2007

Description

SURFACE-TREATED COPPER FOIL HAVING GRAYED SURFACE, PROCESS FOR PRODUCING THE SAME AND ELECTROMAGNETIC WAVE SHIELDING CONDUCTIVE MESH FOR FRONT PANEL OF PLASMA DISPLAY WHEREIN USE IS MADE OF THE SURFACE-TREATED COPPER FOIL}

A surface-treated copper foil having a grayed surface, and an electromagnetic wave shielding metal mesh for a front panel of a plasma display using the surface-treated copper foil. In particular, it provides the surface-treated copper foil which is suitable for manufacture of the electromagnetic shielding conductive mesh for the front panel of a plasma display.

BACKGROUND OF THE INVENTION Conductive meshes for shields in plasma display panels have evolved from metallized fiber fabrics to conductive meshes. Several methods are established for manufacture of this conductive mesh. One of them laminates a surface-treated copper foil to a PET film and bonds it, and manufactures it using the photolithographic etching method. And the other is the conductive mesh of the surface-treated copper foil single body which etched the surface-treated copper foil with the support base material by the photolithographic etching method, and then peeled off the support base material.

Further, in accordance with recent demands for power saving, development has been conducted aiming at a plasma generation signal voltage of 200V to 50V level, and the reduction in luminance accompanying the decrease in the voltage is made thinner in the circuit width of the conductive mesh. Attempts have been made to reduce the coverage of the front glass panel by the conductive mesh. For this reason, it has been performed to make the thickness of the conductive mesh thin and to facilitate the etching process. One of them forms a seed layer serving as a base for electroplating by sputtering deposition on a PET film, and then forms a thin copper layer by electrolytic copper plating and the like, and then finens the mesh line width by photolithography etching. Has been produced.

In any of these methods, the conductive mesh itself may be embedded within the front panel and visible from the surface through the windshield, and among those skilled in the art, having a blackened surface or a multi-browned surface. Surface-treated copper foil has been used.

(Surface treatment copper foil provided with the current blackening process surface)

One surface of the surface-treated copper foil processed with this electroconductive mesh is processed by black, and is made to make the brightness of transmitted light stand out. Conventionally, the blackening process etc. which form the copper oxide layer performed in order to improve the adhesiveness with the resin layer of an inner layer circuit of a multilayer printed wiring board have been dedicated for this process.

By the way, the blackening process mentioned above had a serious problem. In other words, if a large amount of copper black oxide is added to the surface of the copper foil, a satisfactory black screen can be obtained. By the way, the black oxide of copper formed on the surface of copper foil is easy to fall off from a black screen, so that the adhesion amount increases, so-called powder fall phenomenon occurs, and the blackening process surface becomes easy to deal with, and becomes difficult to handle. Moreover, black color tone stability is also lacking.

When the powder fall phenomenon occurs, it may be incorporated in a place where no dropped black oxide is needed, or may be dispersed in the transparent adhesive layer during the transparent treatment for integrating with the glass of the front panel to deteriorate the transparency.

On the other hand, as blackening treatment which can form a favorable black screen, although general black nickel plating, nickel sulfide plating, cobalt plating, etc. have been examined, the etching process from the blackening process surface side can be performed by the normal copper etching process. There was a problem that there was not. In particular, a surface-treated copper foil having a blackened surface in which cobalt and nickel are precipitated in large amounts cannot be solved by the problem of powder falling, and has been an expensive product because expensive nickel or the like is used in a large amount.

(Surface-treated copper foil provided with current multi-browning treatment surface)

On the other hand, the manufacturing technology of plasma display panels has matured, and conventionally, surface-treated copper foils having a favorable black screen have been required. However, with the advancement of manufacturing technology and management, a high level of black density of the electromagnetic shielding mesh is not required. Rather, there is a need for an electromagnetic wave shielding mesh having a mesh pattern having a high aperture ratio in which low cost, easy etching, and light transmittance are stable.

Therefore, the copper foil provided with the cobalt black plating film currently distributed to the market has a problem that the etching process of the cobalt layer using copper etchant is difficult, and it is attempted to reduce dissimilar metals and to have a brownish-brown tint. Has been.

In order to reliably satisfy the condition of low cost and to be easy to etch, it has been studied to reduce the adhesion amount of cobalt or the like to the market by bringing the surface of the surface-treated copper foil into a dark brown state before reaching blackening.

However, the drawback of the surface-treated copper foil which has the conventional dark brown surface was that the color of the dark brown surface was not uniform, and the whole surface was uneven. That is, the uniformity of the dark brown treatment in the same plane was not achieved, causing a nonuniformity in the mesh cross-sectional shape obtained by etching. In addition, the dark brown surface was susceptible to damage simply by lightly rubbing the surface.

Therefore, in the market, the surface-treated copper foil which has provided the browning process layer which has a uniform dark brown, and is easy to carry out an etching process has been calculated | required.

And the copper foil provided with the above-mentioned blackening process surface and the multi-browning process surface all have a problem of stability of a hue, and in order to reduce the non-uniformity between lots, it is necessary to perform manufacturing condition management strictly, and enormous process control effort There was a certain limitation in supplying the market by lowering the price of the product due to the cost and cost. As a prior art considered generally relevant, the following documents are mentioned.

[Non-Patent Document 1] Technical Trends of PDP Materials (Hitachi Kasei Technical Report No. 33 (1999-7))

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

〈Problems to Solve Invention〉

However, the copper foil provided with the above-mentioned blackening process surface and the multi-browning process surface has the problem of the color tone which can be confirmed in the copper foil state, and is the color tone when it is processed by the electromagnetic wave shielding conductive mesh and attached to the front panel of a plasma display. It was not considered.

Herein, a method of manufacturing the most common front filter will be briefly described. When manufacturing the conductive mesh 15 of 200 micrometers pitch and 20 micrometers or less of line widths, as shown to FIG. 14 (a), PET film F is prepared and the adhesive layer 20 is provided in the surface. It will be in the state shown in FIG.14 (b). As shown in Fig. 14C, the metal seed layer S having a thickness of 1 µm or less is formed on the adhesive layer 20 by the sputtering method, the electroless plating method, or the like. As shown in Fig. 2), the copper layer C having a level of 3 µm or less is formed by electrolytic copper plating.

Then, on the copper layer C, an etching resist layer R is formed as shown in Fig. 14E, and the etching resist layer R is electrically conductive as shown in Fig. 15F. The mesh pattern P is exposed, developed and etched as shown in Fig. 15 (g), and brought into the state shown in Fig. 15 (h), and the etching resist layer R is peeled off, and Fig. 15 (i) The state shown in FIG.

Subsequently, by blackening the surface of the conductive mesh 15, it becomes a state in which the blackening process layer 17 was formed in the surface of a conductive mesh as shown in FIG.15 (j). And when this blackening process is complete | finished, as shown in FIG. 16 (k), the 1st transparent board | substrate 19a which comprises a front filter is made to contact and press blackened conductive mesh 5 ', and is pressed. As shown in Fig. 16 (l), the blackened conductive mesh 15 'is pushed into the adhesive layer 20 to perform a transparent treatment. And a PET film is peeled off as shown to FIG. 16 (m). Finally, as shown in Fig. 16 (n), the adhesive layer 20 and the second transparent substrate 19b are bonded to each other so that the front filter 11 is completed.

As can be seen from the above process, the surface of the conductive mesh may be blackened and visually recognized in the state in which it is blackened or multi-browned before the transparent treatment and is invisible after the transparent treatment. .

In the future, the digitization of terrestrial waves is inevitable, and the speed of transmission of image signals is inevitable, and the law on electromagnetic shield is considered in consideration of the effect on human body and the effect on other electronic devices. It is expected that the draft will be strengthened, and the demand for an electromagnetic shield having excellent electromagnetic shielding property using conductive mesh is expected to be higher, and a cheap and high quality conductive mesh is required.

〈Means for solving the problem〉

Therefore, the present inventors earnestly researched and produced the electroconductive shielding electromagnetic mesh using the surface-treated copper foil provided with the graying process surface described below. By using the surface-treated copper foil provided with this graying process surface, the color tone of the surface of the electromagnetic wave shielding conductive mesh is gray before the transparent process in the front-end filter manufacturing process of a plasma display panel, and the electromagnetic wave shielding conductive mesh after the process of transparentization The surface becomes black and can be recognized.

(Surface Treatment Copper Foil Having Gray Surface)

The surface-treated copper foil provided with the graying process surface which concerns on this invention includes the case where a rustproof process layer is not provided and the case where a rustproof process layer is provided. Therefore, although an antirust process layer is not essential, it is necessary in order to ensure long-term storage property as surface-treated copper foil. Hereinafter, the surface-treated copper foil which concerns on this invention is demonstrated.

1st surface-treated copper foil: The surface-treated copper foil which concerns on this invention "is a surface-treated copper foil provided with the graying process surface on the rough surface of an electrolytic copper foil, and the said grayening process surface is made to one side of a copper foil layer. A cobalt sulfate plating layer having a weight thickness of 200 mg / m 2 to 350 mg / m 2 and a cross-sectional height of the grayed surface is 200 nm or less (hereinafter referred to as "first surface-treated copper foil"). The cross-sectional layer structure of this surface-treated copper foil 1a is shown typically.

In FIG. 1, the cobalt sulfate plating layer 4 is formed in the rough surface of the electrolytic copper foil 7, and the roughening process is performed by the fine copper particle 3 on the opposite surface (corresponding to a gloss surface in the case of electrolytic copper foil). The surface-treated copper foil 1a of the implemented state is shown as an example. However, the opposite surface of the copper foil used at this time may be a roughening process or the roughening process may not be performed. Therefore, in FIG. 2, the surface-treated copper foil 1b when the roughening process of the opposite surface is abbreviate | omitted is shown typically. The roughening process layer 2 comprised from the fine copper particle 3 is formed for the purpose of adhesive improvement with a base material, etc., and may be provided as needed. As for the method in the case of forming this roughening process layer 2, the method of adhering and forming fine copper particle, making fine copper oxide adhere, etc. can be employ | adopted as mentioned above, The limitation in particular in a roughening process method is none.

Then, the cobalt sulfate plating layer 4 is provided on the rough surface of the copper foil layer 7 with constant irregularities. As roughness which a rough surface has here, the roughness corresponding to the rough surface of the electrolytic copper foil with a thickness of 35 micrometers or less of nominal thickness is most suitable, and it is measured by the stylus roughness meter of 2 micrometers of curvature radius of a tip of a stylus tip. It is preferable that average roughness Ra prescribed | regulated to JIS B 0601 at the time of carrying out exists in the range of 1.0 micrometer or less and 10-point average roughness Rz in 4.0 micrometers or less. When it is rougher than this roughness, the color tone of the grayed surface-treated copper foil is lacking, the etching accuracy when etching and processing into a mesh shape is deteriorated, and the production yield of high-quality electromagnetic shielding conductive mesh is lowered. There is this. And more preferably, average roughness Ra is 0.5 micrometer or less and 10-point average roughness Rz is 2.8 micrometers or less. Stability of the gray tint of a surface-treated copper foil improves remarkably, and the black tint after a transparency process in the front-panel manufacturing process of a plasma display panel also becomes small.

The cobalt sulfate plating layer 4 herein means a layer formed by a plating method using a cobalt sulfate solution. And this cobalt sulfate plating layer 4 can be visually recognized in gray in the state of surface-treated copper foil. By the way, in the above-mentioned manufacturing process of the front panel of the plasma display panel, the film is transparent and coated on the surface of the grayed surface with a resin film or an adhesive resin. The change in the hue in this way is that when clothes of a dark hue get wet with water, the water film is formed on the surface of the clothes which should be rough, and the diffuse reflection of the light received by forming a smooth surface is suppressed, and the color is perceived as darker. It is the same as it can be.

This cobalt sulfate plating layer 4 has a weight thickness of 200 mg / m 2 to 350 mg / m 2 by employing the production method described later, so that the cobalt sulfate plating layer is excellent in solubility in the copper etching solution and the formation of a grayed surface is possible. The cobalt layer of the copper foil provided with the black plating film using the conventional cobalt layer was 100 mg / m <2> of the weight thickness, and was very thick and differed in quality, such as the solubility of a plating layer. As a result, because of the thickness, the dissolution rate by the copper etchant was slowed, and the element itself called cobalt accumulated in the copper etchant at a high concentration, which caused a lowering of the titer of the etchant. In addition, the converted weight in this invention is the value converted into the cobalt weight. The converted weight is obtained by dissolving the surface-treated copper foil in an acid solution, obtaining an amount of cobalt per unit area by plasma emission spectroscopy, etc., and converting it to the weight per 1 m 2 of the surface-treated copper foil.

Moreover, it turned out that the cobalt plating layer is easy to melt | dissolve in a copper etching liquid, also largely affected by the plating conditions at the time of cobalt plating. That is, the cobalt plating film obtained when employ | adopting the manufacturing method of the surface-treated copper foil which concerns on this invention mentioned later becomes the thing excellent in the etching characteristic most.

As for the 2nd characteristic with the surface-treated copper foil which concerns on this invention, the surface shape of the graying process surface is not very coarse, but the cross-sectional height which the said graying process surface has is a large feature 200 nm or less. That is, it can be said to be an extremely smooth graying process surface. However, in order to avoid misunderstanding, it is obvious that there exists a deviation within the range of a normal manufacturing process, and the cross-sectional height in all positions does not necessarily need to be 200 nm or less, and the variation of a manufacturing process is not necessarily made. Naturally, the cross-sectional height exceeding 200 nm may exist in the degree to which it reflects. In order to measure the cross-sectional height of the cobalt sulfate plating layer 4 of the surface-treated copper foil 1 which concerns on this invention, the FIB observation image observed by the cross section using the FIB analyzer is shown in FIG. 3, the thing which formed the grayening process surface in the gloss surface of an electrolytic copper foil is shown. In addition, this FIB observation image is observed from the direction which has an angle of 60 degrees with respect to an observation surface.

As can be seen from FIG. 3, it is apparent that the cross section of the grayed surface has a certain unevenness, and when monitoring such unevenness, it is common to use a tactile surface roughness meter. By the way, as can be seen from the scale of FIG. 3, it is considered that the surface roughness meter is uneven at a level at which accurate roughness measurement is impossible. Therefore, in this invention, as a value corresponding to Rmax when measured with a surface roughness meter, the maximum difference of the mountain part and valley part in the visual field on a FIB observation is called "cross section height." The location shown by "d" in FIG. 3 becomes the cross-sectional height of FIG. 3, and it can be judged that it is about 80 nm. In addition, in FIG. 3, the cobalt sulfate plating layer 4 is formed along the shape of the copper foil surface at an extremely uniform thickness, and maintains a state of being completely in contact with the copper foil surface of the base, and thus the cobalt sulfate plating layer 4 Problem points such as) are inconspicuous, and you cannot see the place where powder falls.

On the other hand, when FIB is observed from the cross section similarly to the above, the blackening process surface formed on the surface of the conventional copper foil will have the result as shown to FIG. 4 and FIG. That is, it turns out that the shape which comprises the blackening process surface grows in the shape of a twig, and the state which protrudes substantially from the copper foil of a base. Therefore, when the cross-sectional height d at this time is measured, it turns out that the case of FIG. 4 is about 480 nm, and the case of FIG. 5 is about 270 nm, and it is a very rough surface. In addition, the blackened surface having such a branched shape is a surface where the branched portion is easily broken and easily damaged, and in addition, it is natural that powder fall occurs when the broken fragments fall off. It is thought that it causes color unevenness when seen visually from the surface of the heat treatment.

It can be seen that the surface-treated copper foil according to the present invention described above has an extremely smooth surface from the FIB cross-sectional observation image of FIG. 3. And the L value in the Lab color system of this graying process surface becomes 43 or less. Here, as described below, the upper limit is not particularly limited, but about 38 is the lower limit empirically.

In addition, it is preferable that the graying process surface of the surface-treated copper foil which concerns on this invention has a constant gloss, and is represented using glossiness in order to show the grade of the gloss. As for the glossiness of the graying process surface which concerns on this invention, when the said grayening process surface was formed in the rough surface of an electrolytic copper foil, it is preferable that glossiness [Gs (60 degrees)] is 10 or less. When the glossiness is 10 or more, the so-called metallic luster becomes noticeable. On the other hand, also here, although the lower limit of glossiness is not determined, empirically, about 0.5 becomes a lower limit. More preferably, glossiness is in the range of 0.5 to 3.0. Stability of the gray color tone in the case of having glossiness in this range becomes the best.

When the graying-treated surface of the surface-treated copper foil described above is arrange | positioned closely to the surface, it becomes visually recognized as black. The black density at the time of directly observing the grayed-out surface at this time is O.7-1.2 (measurement condition: StatusT, Sampling aparture 1.5 * 2mm, no polarizing filter), and a transparent resin film on the surface of this grayed-side surface When it is placed in close contact, the black concentration is 1.4 or more (experimentally, the upper limit is about 1.8). Conventionally, the black density of the blackening process surface of the surface-treated copper foil used for the electromagnetic wave shielding mesh of a plasma display panel is about 1.0 or more when the blackening process surface was observed directly (this inventor obtained in the market) It is 1.30-1.67 when measured by a possible product, and when a transparent resin film is arrange | positioned closely to the surface of this blackening process surface, black density is 1.5 or more (1.40-1.87 when measured by the product which is available on the market by this inventor). From this, when using the surface-treated copper foil provided with the graying process surface which concerns on this invention, and arrange | positioning a transparent resin film closely to this surface, it can be said that it becomes sufficient black density, considering that black density is about 1.4 or more. In addition, the black density | concentration in this invention was measured based on JIS B 9620 and JIS B 9622, and employ | adopted the measurement conditions mentioned above.

2nd surface treatment copper foil: This surface treatment copper foil forms the antirust process layer for ensuring long-term storage property on the surface of the above-mentioned 1st surface treatment copper foil. The cross-sectional layer structure of the surface-treated copper foil 1c provided with the antirust process layer 5 on both surfaces of FIG. 6 was typically illustrated. And in FIG. 7, the surface-treated copper foil 1d when the roughening process is abbreviate | omitted to one surface is shown. As long as it aims only at the rust prevention of copper foil, organic rust prevention, such as imidazole and benzotriazole, inorganic rust prevention by zinc alloys, such as zinc or brass generally used, etc. can be used widely. In addition, although the antirust process layer at the time of forming a cobalt sulfate plating layer in one side should be formed in the opposite surface which formed at least the cobalt sulfate plating layer of the surface-treated copper foil which concerns on this invention, even if it forms in both surfaces, it does not interfere. .

However, if the antirust process layer 5 is formed in both surfaces, these antirust process layers will prevent the fall of the fine copper particle 3 of the roughening process layer 2, and as a protective layer of the cobalt sulfate layer 4, respectively. At the same time, it plays a role of maintaining the appearance as a surface-treated copper foil for a long time. It is particularly preferable to provide a zinc-nickel alloy layer or a zinc-cobalt layer in the antirust treatment layer 5. By using these antirust process layer 5 in combination with the cobalt sulfate plating layer 4, it is thought that it can function as a dissolution promoter at the time of carrying out the etching dissolution of the cobalt sulfate plating layer 4. That is, dissolution of the cobalt sulfate plating layer 4 occurs more quickly when the zinc-nickel alloy layer or zinc-cobalt layer is provided than when the cobalt sulfate plating layer 4 alone exists.

In addition, the cross-sectional layer structure of the surface-treated copper foil 1c which provided the antirust process layer 5 and the chromate treatment layer 6 on both surfaces in FIG. 8 and FIG. 9 is shown typically. As can be seen from contrasting each of FIGS. 6 and 8, 7 and 9, the difference from the surface-treated copper foil having the antirust treatment layer 5 differs only in that the chromate treatment layer 6 is provided. In addition, the other structure is the same.

The chromate treatment layer 6 is formed on one side or both sides after the antirust treatment layer 5 made of a zinc-nickel alloy, a zinc cobalt alloy, or the like is formed. The presence of this chromate treated layer 6 significantly improves the oxidation resistance of the surface-treated copper foil and effectively prevents cosmetic corrosion such as oxidation discoloration.

(Method for producing surface-treated copper foil having a grayed surface)

Manufacturing method of 1st surface treatment copper foil

It is preferable to employ | adopt the manufacturing method containing the following processes as the manufacturing method of the above-mentioned 1st surface treatment copper foil. This production method is based on the premise that a stirring bath is employed.

The copper foil used by the manufacturing method of the surface-treated copper foil which concerns on this invention does not ask whether the roughening process is performed to the opposite surface which forms a cobalt sulfate plating layer as mentioned above. Although described for the case here, there is no restriction | limiting in particular in the conditions at the time of performing a roughening process, For example, when forming an ultrafine copper particle, generally the copper electrolyte solution containing arsenic can be used. For example, as a copper sulfate solution, copper concentration of 5 to 10 g / l, sulfuric acid concentration of 100 to 120 g / l, chlorine concentration of 20 to 30 ppm, 9-phenyl acridine 50 to 300 mg / l, liquid temperature 30 to 40 ℃, Conditions such as current density of 5 to 20 A / dm 2.

In the process of a), 10 g / l-40 g / l of cobalt sulfate (7-hydrate) is included in the rough surface of the copper foil mentioned above, The cobalt sulfate plating liquid which made pH more than 4.0 and 30 degrees C or less of liquid temperature is used as a stirring bath. And electrolytic at a current density of 4 A / dm 2 or less to form a gray cobalt sulfate plating layer. That is, what is fundamentally different from the manufacturing method A of a 1st surface-treated copper foil here is the point which electrolytically stirs the said cobalt sulfate plating liquid at the time of performing cobalt sulfate plating. This cobalt sulfate concentration tends to produce a satisfactory graying state as the cobalt sulfate concentration is lower. However, when the cobalt sulfate (7-hydrate) in the cobalt sulfate plating solution is less than 10 g / l, the electrodeposition rate of the cobalt sulfate plating layer formed by employing a stirring bath becomes slow, and the thickness of the nickel sulfate layer is uneven. This tends to increase, resulting in a lack of industrial productivity. On the other hand, when cobalt sulfate (7 hydrate) exceeds 40 g / l, the cobalt sulfate plating layer formed will become difficult to form dense unevenness, and as a result will not be in a good gray state.

Moreover, it is preferable to adjust the solution pH of the cobalt sulfate plating liquid at this time to the range of 4.0 or more. And more preferably, it is the range of 4.5-5.5. In this range, a product yield is high and a favorable gray cobalt plating layer can be obtained. In order to perform this pH adjustment, it is not preferable to add another electrolyte, such as sodium hydroxide or potassium hydroxide. A metal color becomes easy to add to the gray of a cobalt plating layer.

Therefore, the solution pH is to stabilize the concentration of metal ions in the solution, resulting in a range of 4.0 or more. In order to stabilize the cobalt ion concentration in the solution as described above, cobalt ions are dissolved and supplied by dissolving the electrodeposited cobalt ions using a soluble cobalt electrode, or the cobalt ions are continuously added by appropriately using cobalt hydroxide. It is preferable to employ | adopt the method etc. which stabilize a density | concentration.

And it is preferable to use the cobalt sulfate plating liquid at this time, making the liquid temperature 30 degrees C or less. The liquid temperature at this time tends to be able to obtain a favorable graying process surface, so that it is low. When liquid temperature is set to 30 degrees C or less, in the manufacturing method A of the said 1st surface treatment copper foil, it becomes possible to obtain a favorable graying process surface beyond having performed blackening process on the copper foil surface without a roughening process.

It is preferable that the stirring at this time makes the solution flow velocity of the result of stirring into the range of 20 cm / s-40 cm / s. When the flow rate of the solution is less than 20 cm / s, in the above solution composition, the ion supply to the adhered surface of the cobalt to be electrodeposited is delayed, the time required for electrodeposition becomes long, and the color tone of the grayed surface obtained is further obtained. Nonuniformity is easy to occur. On the other hand, when the flow rate of a solution exceeds 40 cm / s, the ion supply rate by stirring becomes too large, the graying-treated surface approaches blackening, and also the metal gloss becomes strong, and the graying aimed at by this invention No treatment surface.

A current of 4 A / dm 2 or less is used for the current density at the time of electrolysis. Within this range, the cobalt sulfate plating layer having good fine unevenness excellent in adhesion with an organic material or the like can be formed even without roughening the copper foil surface. Usually, when it is going to obtain the black-plated surface with an unevenness | corrugation, the method of flowing the electrolytic electric current which goes into an excess baking region is employ | adopted. However, in this case, the smaller the current density used for electrolysis, the more stable the graying treatment tends to be possible. Therefore, the current density should be adopted as small as possible, but considering the industrial productivity, the current density of 0.5 A / dm 2 can be determined as the lower limit. On the other hand, when the current density exceeds 4 A / dm 2, the color tone close to the blackening treatment tends to be obtained, and the meaning of adopting this manufacturing method is ignored. In addition, the graying treatment surface formed in the range of the current density mentioned above does not generate | occur | produce a powder fall from there.

In the process of b), the copper foil which passed the above process is washed with water and dried, and the surface-treated copper foil which makes a cobalt sulfate plating layer the graying process surface is obtained. There is no restriction | limiting in particular in the water washing method and the drying method here, The method normally considered can be employ | adopted.

Manufacturing method of 2nd surface treatment copper foil

In the case of the 2nd surface-treated copper foil, similarly to the manufacturing method of the 1st surface-treated copper foil mentioned above, the surface-treated copper foil which makes a cobalt sulfate plating layer into a graying process surface is manufactured, and then, an antirust process layer is formed will be. Therefore, the production flow is "a) to form a gray cobalt sulfate plating layer on the gloss surface of copper foil, b) to form a rust prevention layer on both surfaces or one side of the copper foil on which the gray cobalt sulfate plating layer was formed, c) the Then washed with water and dried. That is, the formation process of an antirust process layer is only added to the manufacturing method of a 1st surface treatment copper foil.

Therefore, only the formation process of a rust prevention process layer is demonstrated here. An antirust treatment layer is formed on both surfaces or one side of the copper foil in which the formation of the gray cobalt sulfate plating layer is completed. In the case of using conventionally known organic rust prevention such as imidazole and benzotriazole, and inorganic rust prevention by zinc alloys such as zinc or brass which are generally used, no explanation is necessary and the conventional method is not required. The detailed description thereof will be omitted since it is considered to be followed.

Hereinafter, the case where the antirust process layer is formed by plating by using a zinc-nickel alloy plating solution or a zinc-cobalt alloy plating solution will be described. First, zinc-nickel alloy plating will be described. Although there is no restriction | limiting in particular in the zinc-nickel alloy plating liquid used here, For example, the nickel concentration using nickel sulfate is 1-2.5 g / l, and the zinc concentration using zinc piloline is 0.1-1 g / l, and phyllolic acid Potassium 50 to 500 g / l, liquid temperature 20 to 50 ° C, pH 8 to 11, current density 0.3 to 10 A / dm 2, and the like are employed.

Next, zinc-cobalt alloy plating is demonstrated. Although there is no restriction | limiting in particular in the zinc-cobalt-alloy plating liquid used here, For example, the cobalt density | concentration using cobalt sulfate is 1-2.5 g / l, and the zinc concentration | concentration using zinc phyllodate is 0.1-1 g / l, phylophosphoric acid Potassium 50 to 500 g / l, liquid temperature 20 to 50 ° C, pH 8 to 11, current density 0.3 to 10 A / dm 2, and the like are employed. The antirust process layer which combined this zinc-cobalt alloy plating and the chromate treatment mentioned later shows especially outstanding corrosion resistance performance.

In the case of the second surface-treated copper foil, more excellent corrosion resistance can be obtained by forming a chromate layer after forming a zinc-nickel alloy layer, a zinc-cobalt alloy layer, or the like on the surface of the copper foil. That is, what is necessary is just to provide the chromate processing process after formation of the antirust process layer mentioned above. In this chromate treatment process, you may employ | adopt any method of the electrolytic chromate treatment which contacts with a chromate solution and the said copper foil surface, or performs electrolytic treatment in a chromate solution, and forms a chromate film. Moreover, also about the chromate solution used here, the thing of the range used by a conventional method can be used. And the surface-treated copper foil provided with the graying process surface is then obtained by washing with water and drying.

(Electromagnetic shielding conductive mesh)

The surface-treated copper foil provided with the graying process surface which concerns on this invention described above does not have the powder fall off from the graying process surface, and also has gray gray, and the graying process layer is a normal copper etching process. Etch removal is possible. Therefore, it can process into arbitrary shapes easily using the process of manufacturing a printed wiring board. Considering this, it can be said that it is optimal for the use of the electromagnetic shielding conductive mesh mounted on the front panel of the plasma display panel.

<Effects of the Invention>

Although the surface-treated copper foil provided with the graying process surface which concerns on this invention is a very thin cobalt sulfate plating layer, it shows the favorable gray enough to be used for the electromagnetic shielding conductive mesh of the front panel of a plasma display panel. . Since the cobalt content is small, the etching characteristics are good, and the solution life can be prolonged without lowering the titer of the conventional iron chloride and sulfuric acid-hydrogen peroxide-based copper etching solutions.

Moreover, in the manufacturing method of the surface-treated copper foil which concerns on this invention, it is possible to manufacture the said surface-treated copper foil with high product yield, and the cobalt sulfate plating layer formed employ | adopting the manufacturing conditions mentioned above is melt | dissolved in copper etching liquid most efficiently. .

BRIEF DESCRIPTION OF THE DRAWINGS The figure which showed typically the cross-sectional layer structure of the surface-treated copper foil provided with the graying process surface.

FIG. 2 is a diagram schematically showing a cross-sectional layer structure of a surface-treated copper foil having a grayed surface.

FIG. 3: FIB observation image of the cross-sectional layer structure of the surface-treated copper foil provided with the graying process surface.

FIG. 4: FIB observation image of the cross-sectional layer structure of the surface-treated copper foil provided with the graying process surface.

FIG. 5: FIB observation image of the cross-sectional layer structure of the surface-treated copper foil provided with the graying process surface.

6 is a diagram schematically illustrating a cross-sectional layer structure of a surface-treated copper foil having a grayed surface.

The figure which shows typically the cross-sectional layer structure of the surface-treated copper foil provided with the graying process surface.

FIG. 8: is the figure which shows typically the cross-sectional layer structure of the surface-treated copper foil provided with the graying process surface.

9 is a diagram schematically showing a cross-sectional layer structure of a surface-treated copper foil having a grayed surface.

The scanning electron microscope image of the roughening process copper foil surface.

Fig. 11 is a scanning electron microscope image of low magnification of a gray cobalt sulfate plating layer.

12 is a scanning electron microscope image of high magnification of a gray cobalt sulfate plating layer.

13 is a scanning electron microscope image of an etching test pattern.

14 is a schematic diagram showing a manufacturing flow of a front panel of a conventional plasma display panel.

15 is a schematic diagram illustrating a manufacturing flow of a front panel of a conventional plasma display panel.

16 is a schematic diagram showing a manufacturing flow of a front panel of a conventional plasma display panel.

Explanation of the sign

1a, 1b, 1c, 1d, 1e, 1f: surface treated copper foil

2: harmonic treatment layer

3: fine copper particles

4: cobalt sulfate plating layer

5: antirust treatment layer (zinc-nickel alloy layer or zinc-cobalt alloy layer)

6: chromate treated layer

7: copper foil

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

First embodiment

In this embodiment, the 1st surface treatment copper foil 1a shown in FIG. 1 was manufactured, the electromagnetic wave shielding conductive mesh shape was experimentally manufactured by the etching method, and the etching performance was confirmed.

In this embodiment, the copper foil of 15 micrometers of nominal thickness obtained by electrolyticating a copper sulfate solution was used. And copper foil was immersed in this solution for 30 second using the sulfuric acid concentration 150g / l and the dilute sulfuric acid solution of 30 degreeC of liquid temperature, and the surface was cleaned.

And the roughening process was performed to the gloss surface of 15 micrometers of nominal thickness electrolytic copper foil. The roughening process at this time attaches and forms this fine copper particle 3 to one surface of the copper foil 7, The density | concentration is 10 g / l of copper sulfate, 100 g / l of sulfuric acid, 25 ppm of chlorine in a copper sulfate system solution, and 9-phenyl ah. The electrolytic conditions of the Credin 140 mg / l solution, the liquid temperature of 38 degreeC, current density of 15 A / dm <2>, and electrolysis time of 2 second were employ | adopted. It is FIG. 10 which showed the roughening process copper foil surface.

As a process, the cobalt sulfate plating layer was formed as a process on the rough surface of the said electrolytic copper foil. Formation of the cobalt sulfate plating layer was carried out at a current density of 1 A / dm 2 for 12 seconds using a cobalt sulfate plating solution having a cobalt sulfate (7 hydrate) of 20 g / l and pH adjusted to 5.5 and a solution temperature of 27 ° C. as a stirring bath. By electrolysis, the gray cobalt sulfate plating layer (thickness converted into 27 mg / m <2>) was formed. At this time, the cobalt ion concentration in the solution was not particularly adjusted. This is because the adjustment of the metal ion concentration is unnecessary because it is a short time electrolysis. The cobalt sulfate plating layer formed in FIG. 11 and FIG. 12 is shown. FIG. 11 is a scanning electron microscope image of low magnification observation, and FIG. 12 is a scanning electron microscope image of high magnification observation. As can be clearly seen from FIG. 12, the roughness shape of the base electrolytic copper foil can be grasped clearly, and it can be understood that the graying treatment layer itself is extremely thin.

As the process of b), pure water is sufficiently showered and washed, the heater is kept for 4 seconds in a drying furnace having an atmospheric temperature of 150 ° C. with an electric heater to blow off moisture, and has a grayed surface of very good color tone. One surface-treated copper foil 1a was obtained. In addition, between each process mentioned above, the water washing process by the pure water for 15 second is provided in principle, and the carry-in of a pretreatment process solution is prevented.

<Physical properties of surface-treated copper foil>

When the cross section of the surface-treated copper foil provided with the graying process surface obtained through the above process was observed with the FIB apparatus, the cross section shown in FIG. 3 is obtained, and the cross-sectional height d of the said graying process surface is 80 nm, L value in the Lab colorimetric system of the said grayening process surface was 41, and glossiness [Gs (60 degrees)] was 2.5. In addition, color unevenness was not seen on the grayed-out surface, and powder fall-off in the tape test which stuck and peeled off the adhesive tape on the said surface was not confirmed.

In addition, it was judged whether the grayed process surface of the obtained surface-treated copper foil was processed into the electromagnetic wave shielding mesh for plasma displays, and when it became black when it became transparent. The black density of the grayed surface before forming the transparent resin film was 0.9. The grayed surface was coated with an epoxy resin as a transparent resin film, dried and cured, and grayed out through the cured epoxy resin layer. An alternative method of observing the changed color tone of the treated surface was adopted. As a result, the grayed surface was observed as black with a black density of 1.5.

<Production of electromagnetic wave shielding mesh for plasma display>

The dry film used as an etching resist was bonded to both surfaces of the surface-treated copper foil obtained as mentioned above. Then, only the dry film on the grayed-out surface side was superimposed with a mask film for a test for producing an electromagnetic wave shielding conductive mesh, a mesh pitch of 200 μm, a mesh line width of 10 μm, and a mesh bias angle of 45 °. The conductive mesh pattern to be exposed was subjected to ultraviolet exposure. At this time, ultraviolet light was also exposed to the entire surface of the etching resist layer on the opposite side, so that it could not be removed by subsequent development. It was then developed using an alkaline solution to form an etching pattern.

And the electromagnetic wave shielding conductive mesh was manufactured by copper-etching from the graying process surface side using the iron chloride etching liquid which is copper etching liquid, and then peeling off an etching resist layer. As a result, there was no etching residue and very good etching was performed. In FIG. 13, the etching state of the test pattern (13 micrometer width circuit) for evaluating etching property is shown. As can be seen from FIG. 13, a beautiful circuit having no etching residue and extremely excellent etching factor can be obtained.

Second embodiment

In this embodiment, as shown in Fig. 6, a second surface-treated copper foil 1c having a zinc-nickel alloy layer as a rust-preventing layer was produced, and the electromagnetic shielding conductive mesh shape was experimentally tested by an etching method. It was prepared to confirm the etching performance. Therefore, since it is common to 1st Example until the graying process layer by a cobalt sulfate plating layer is formed, only rust prevention process conditions are demonstrated. On the other hand, the converted thickness of the gray cobalt sulfate plating layer is 270 mg / m 2 as in the first embodiment.

Here, plating was performed on both surfaces of the copper foil in which the formation of the gray cobalt sulfate plating layer was finished on one surface of the first embodiment by using a zinc-nickel alloy plating solution to form a zinc-nickel alloy layer on both surfaces. The zinc-nickel alloy layer has a nickel concentration of 2.0 g / l using nickel sulfate, a zinc concentration of 0.5 g / l using zinc pilodate, 250 g / l of potassium phylate, liquid temperature 35 ° C., pH 10, and current rate. Electrolysis was carried out for 5 seconds under the condition of 5 A / dm 2, and electrolytic precipitation was uniformly and smoothly on both surfaces.

As in the first embodiment, the pure water was sufficiently showered and washed, the heater was kept for 4 seconds in a drying furnace having an ambient temperature of 150 ° C. with a heater to blow off moisture, and the surface treatment was provided with a grayed surface of very good color tone. Copper foil (1c) was obtained. In addition, between each process mentioned above, the water washing process by pure water for 15 second is provided in principle, and the solution of a pretreatment process is not carried in.

<Physical properties of surface-treated copper foil>

When the cross section of the surface-treated copper foil provided with the graying process surface obtained through the above process was observed with the FIB apparatus, the cross section as shown in FIG. 3 was obtained and the cross-sectional height of the said graying process surface is 75 nm, L value in the Lab colorimetric system of the said grayening process surface was 39, and glossiness [Gs (60 degrees)] was 2.5. In addition, color unevenness was not seen on the grayed-out surface, and powder fall-off in the tape test which stuck and peeled off the adhesive tape on the said surface was not confirmed.

In addition, it was judged whether the grayed process surface of the obtained surface-treated copper foil was processed into the electromagnetic wave shielding mesh for plasma displays, and when it became black when it became transparent. The black density of the gray-treated surface before forming a transparent resin film was 0.9, and as a result of evaluating by the alternative method similar to Example 1, the gray-treated surface was observed as black with a black density of 1.6.

<Production of electromagnetic wave shielding mesh for plasma display>

In the same manner as in the first example, an electromagnetic wave shielding conductive mesh was fabricated using the obtained surface-treated copper foil. As a result, even if the antirust process layer existed, there was no problem in the etching operation, there was no etching residue, and very good etching was performed.

Third embodiment

In the present embodiment, as shown in Fig. 8, a second surface-treated copper foil 1e having a zinc-nickel alloy layer and a chromate treatment layer as an antirust treatment layer is produced, and the electromagnetic shielding conductive mesh shape is etched. Experimentally prepared to confirm the etching performance. Therefore, since it is common to 1st Example until the graying process layer by a cobalt sulfate plating layer is formed, only rust prevention process conditions are demonstrated. On the other hand, the converted thickness of the gray cobalt sulfate plating layer is 270 mg / m 2 as in the first embodiment.

In the formation of the antirust treatment layer, a zinc-nickel alloy layer was formed on both surfaces using a zinc-nickel alloy plating solution, and then chromate-treated on both surfaces. Here, electrolytic chromate treatment was adopted, and electrolytic conditions were made into chromic acid 5.0g / l, pH 11.5, liquid temperature 35 degreeC, current density 8A / dm <2>, and electrolysis time 5 second.

When the formation of the chromate layer is completed, the pure water is sufficiently showered and washed, the heater is kept for 4 seconds in a drying furnace having an atmospheric temperature of 150 ° C. with an electric heater to blow off moisture, and the grayed surface having a very good color tone is provided. Surface-treated copper foil (1e) was obtained. In addition, between each process mentioned above, the water washing process by the pure water for 15 second is provided in principle, and the carry-in of a pretreatment process solution is prevented.

<Physical properties of surface-treated copper foil>

When the cross section of the surface-treated copper foil provided with the graying process surface obtained through the above process was observed with the FIB apparatus, the cross section as shown in FIG. 3 was obtained, and the cross-sectional height of the said graying process surface is 75 nm, The L value in the Lab color system of the graying process surface was 40, and glossiness [Gs (60 degrees)] was 2.3. In addition, color unevenness was not seen on the grayed-out surface, and powder fall-off in the tape test which stuck and peeled off the adhesive tape on the said surface was not confirmed.

In addition, it was judged whether the grayed process surface of the obtained surface-treated copper foil was processed into the electromagnetic wave shielding mesh for plasma displays, and when it became black when it became transparent. The black density of the grayed-out surface before forming a transparent resin film was 0.9, and as a result of evaluation by the alternative method similar to Example 1, the grayed-out surface was observed as black with a black density of 1.5.

<Production of electromagnetic wave shielding mesh for plasma display>

In the same manner as in the first example, an electromagnetic wave shielding conductive mesh was fabricated using the obtained surface-treated copper foil. As a result, even if the antirust process layer existed, there was no problem in the etching operation, there was no etching residue, and very good etching was performed.

Fourth embodiment

In this embodiment, as shown in Fig. 6, a second surface-treated copper foil 1c having a zinc-cobalt alloy layer as a rust-preventing layer is produced, and the electromagnetic shielding conductive mesh shape is experimentally tested by an etching method. It was prepared to confirm the etching performance. Therefore, since it is common to 1st Example until the graying process layer by a cobalt sulfate plating layer is formed, only rust prevention process conditions are demonstrated. On the other hand, the converted thickness of the gray cobalt sulfate plating layer is 270 mg / m 2 as in the first embodiment.

Here, plating was performed on both surfaces of the copper foil after the formation of the gray cobalt sulfate plating system on the glossy surface of the first example using a zinc-cobalt alloy plating solution, and a zinc-cobalt alloy layer was formed on both surfaces. The zinc-cobalt alloy layer has a cobalt concentration of 2.0 g / l using cobalt sulfate, a zinc concentration of 0.5 g / l using zinc chlorate, 250 g / l of potassium phylate, liquid temperature 35 ° C., pH 10, and current density of 5 A. Electrolysis was carried out for 5 seconds under the condition of / dm &lt; 2 &gt;, and electrolytic precipitation was uniformly and smoothly on both surfaces.

Then, as in the first embodiment, the pure water was sufficiently showered and washed, and the surface treatment was provided with a gray-treated surface of very good color tone by blowing water by remaining in the drying furnace having an atmospheric temperature of 150 ° C. for 4 seconds with an electric heater. Copper foil (1c) was obtained. In addition, between each process mentioned above, the water washing process by the pure water for 15 second is provided in principle, and the carry-in of a pretreatment process solution is prevented.

<Physical properties of surface-treated copper foil>

When the cross section of the surface-treated copper foil provided with the graying process surface obtained through the above process was observed with the FIB apparatus, the cross section as shown in FIG. 3 was obtained, and the cross-sectional height of the said graying process surface is 80 nm, The L value in the Lab color system of the graying process surface was 40, and glossiness [Gs (60 degrees)] was 2.5. In addition, color unevenness was not seen on the grayed-out surface, and powder fall-off in the tape test which stuck and peeled off the adhesive tape on the said surface was not confirmed.

In addition, it was judged whether the grayed process surface of the obtained surface-treated copper foil was processed into the electromagnetic wave shielding mesh for plasma displays, and when it became black when it became transparent. The black density of the grayened surface before forming a transparent resin film was 0.93, and as a result of evaluating by the alternative method similar to Example 1, the grayed surface was observed as black with a black density of 1.6.

<Production of electromagnetic wave shielding mesh for plasma display>

In the same manner as in the first example, an electromagnetic wave shielding conductive mesh was fabricated using the obtained surface-treated copper foil. As a result, even if the antirust process layer existed, there was no problem in the etching operation, there was no etching residue, and very good etching was performed.

Fifth Embodiment

As shown in FIG. 8, this Example manufactures the 2nd surface treatment copper foil 1e provided with the zinc-cobalt alloy layer as an antirust process layer, and forms the electromagnetic wave shielding conductive mesh shape by the etching method experimentally. It was prepared to confirm the etching performance. Therefore, since it is common to 1st Example until the graying process layer by a cobalt sulfate plating layer is formed, only rust prevention process conditions are demonstrated. On the other hand, the converted thickness of the gray cobalt sulfate plating layer is 270 mg / m 2 as in the first embodiment.

In the formation of the antirust treatment layer, the zinc-cobalt alloy layer was formed on both surfaces using a zinc-cobalt alloy plating solution, and then chromate-treated on both surfaces. Here, electrolytic chromate treatment was adopted, and electrolytic conditions were made into chromic acid 5.0g / l, pH 11.5, liquid temperature 35 degreeC, current density 8A / dm <2>, and electrolysis time 5 second.

When the formation of the chromate layer is completed, the pure water is sufficiently showered and washed, the heater is kept for 4 seconds in a drying furnace having an atmospheric temperature of 150 ° C. with an electric heater to blow off moisture, and the grayed surface having a very good color tone is provided. Surface-treated copper foil (1e) was obtained. In addition, between each process mentioned above, the water washing process by the pure water for 15 second is provided in principle, and the carry-in of a pretreatment process solution is prevented.

<Physical properties of surface-treated copper foil>

When the cross section of the surface-treated copper foil provided with the graying process surface obtained through the above process was observed with the FIB apparatus, the cross section as shown in FIG. 3 was obtained, and the cross-sectional height of the said graying process surface is 82 nm, The L value in the Lab color system of the graying process surface was 41, and glossiness [Gs (60 degrees)] was 2.4. In addition, color unevenness was not seen on the grayed-out surface, and powder fall-off in the tape test which stuck and peeled off the adhesive tape on the said surface was not confirmed.

In addition, it was judged whether the grayed process surface of the obtained surface-treated copper foil was processed into the electromagnetic wave shielding mesh for plasma displays, and when it became black when it became transparent. The black density of the gray-treated surface before forming a transparent resin film was 0.9, and as a result of evaluating by the alternative method similar to Example 1, the gray-treated surface was observed as black with a black density of 1.6.

<Production of electromagnetic wave shielding mesh for plasma display>

In the same manner as in the first example, an electromagnetic wave shielding conductive mesh was fabricated using the obtained surface-treated copper foil. As a result, even if the antirust process layer existed, there was no problem in the etching operation, there was no etching residue, and very good etching was performed.

Sixth embodiment

This embodiment does not perform roughening treatment on the rough surface of an electrolytic copper foil differently from 1st Example, and forms the graying process layer by the cobalt sulfate plating layer in the rough surface side of an electrolytic copper foil similarly to 1st Example below. And the 2nd surface treatment copper foil 1b shown in FIG. 2 was manufactured and evaluation similar to 1st Example was performed. Therefore, since description of a process overlaps with 1st Example, description here is abbreviate | omitted. On the other hand, the gray cobalt sulfate plating layer had a converted thickness of 268 mg / m 2. The form of the formed cobalt sulfate plating layer is observed as shown in FIG. 11 and FIG. 12.

<Physical properties of surface-treated copper foil>

When the cross section of the surface-treated copper foil provided with the graying process surface obtained through the above process was observed with the FIB apparatus, the cross section as shown in FIG. 3 was obtained, and the cross-sectional height of the said graying process surface is 78 nm, The L value in the Lab color system of the graying process surface was 42, and glossiness [Gs (60 degrees)] was 2.5. In addition, color unevenness was not seen on the grayed-out surface, and powder fall-off in the tape test which stuck and peeled off the adhesive tape on the said surface was not confirmed.

In addition, it was judged whether the grayed process surface of the obtained surface-treated copper foil was processed into the electromagnetic wave shielding mesh for plasma displays, and when it became black when it became transparent. The black density of the gray-treated surface before forming a transparent resin film was 0.9, and as a result of evaluating by the alternative method similar to Example 1, the gray-treated surface was observed as black with a black density of 1.6.

<Production of electromagnetic wave shielding mesh for plasma display>

In the same manner as in the first example, an electromagnetic wave shielding conductive mesh was fabricated using the obtained surface-treated copper foil. As a result, there was no problem in the etching operation, no etching residue, and very good etching was performed.

Seventh embodiment

In this embodiment, similarly to the sixth example, the surface of the electrolytic copper foil is not subjected to the roughening treatment, the surface is grayed out to produce the first surface-treated copper foil 1b shown in FIG. The conductive mesh shape was experimentally prepared by the etching method to confirm the etching performance.

In this embodiment, the copper foil of 15 micrometers of nominal thickness obtained by electrolyticating a copper sulfate solution was used. And copper foil was immersed in this solution for 30 second using 150 g / l of sulfuric acid concentrations, and the dilute acid solution of 30 degreeC of liquid temperature, and the surface was cleaned.

And the cobalt sulfate plating layer was formed in the rough surface of the said copper foil as a) process. Formation of the cobalt sulfate plating layer was carried out for 6 seconds at a current density of 2 A / dm 2 using a cobalt sulfate plating solution having a cobalt sulfate (7 hydrate) of 20 g / l and pH adjusted to 5.5 and a liquid temperature of 27 ° C. as a stirring bath. By electrolysis, the gray cobalt sulfate plating layer (thickness conversion was 275 mg / m <2>) was formed. At this time, the cobalt ion concentration in the solution was not particularly adjusted. This is because the adjustment of the metal ion concentration is unnecessary because it is a short time electrolysis. The form of the formed cobalt sulfate plating layer is observed as shown in FIG. 11 and FIG. 12.

As a step (b), the pure water is sufficiently showered and washed, and the surface-treated copper foil having a gray-treated surface of very good color tone is blown out by keeping moisture for 4 seconds in a drying furnace having an atmospheric temperature of 150 ° C with a heater. 1b). In addition, between each process mentioned above, the water washing process by the pure water for 15 second is provided in principle, and the carry-in of a pretreatment process solution is prevented.

<Physical properties of surface-treated copper foil>

When the cross section of the surface-treated copper foil provided with the graying process surface obtained through the above process was observed with the FIB apparatus, the cross section as shown in FIG. 3 was obtained, and the cross-sectional height of the said graying process surface is 80 nm, The L value in the Lab colorimeter of the grayened surface was 39 and the glossiness [Gs (60 °)] was 2.2. In addition, color unevenness was not seen on the grayed-out surface, and powder fall-off in the tape test which stuck and peeled off the adhesive tape on the said surface was not confirmed.

In addition, it was judged whether the grayed process surface of the obtained surface-treated copper foil was processed into the electromagnetic wave shielding mesh for plasma displays, and when it became black when it became transparent. The black density of the gray-treated surface before forming a transparent resin film was 0.9, and as a result of evaluating by the alternative method similar to Example 1, the gray-treated surface was observed as black with a black density of 1.6.

<Production of electromagnetic wave shielding mesh for plasma display>

In the same manner as in the first example, an electromagnetic wave shielding conductive mesh was fabricated using the obtained surface-treated copper foil. As a result, there was no problem in the etching operation, no etching residue, and very good etching was performed.

Eighth embodiment

In this embodiment, similarly to the sixth example, the surface of the electrolytic copper foil is not subjected to the roughening treatment, the surface is grayed out to produce the first surface-treated copper foil 1b shown in FIG. The conductive mesh shape was experimentally prepared by the etching method to confirm the etching performance.

In this embodiment, the copper foil of 15 micrometers of nominal thickness obtained by electrolyticating a copper sulfate solution was used. And copper foil was immersed in this solution for 30 second using 150 g / l of sulfuric acid concentrations, and the dilute acid solution of 30 degreeC of liquid temperature, and the surface was cleaned.

And the cobalt sulfate plating layer was formed in the rough surface of the said copper foil as a) process. The formation of the cobalt sulfate plating layer was performed by adjusting the cobalt sulfate (7 hydrate) to 40 g / l and pH to 5.5, using a cobalt sulfate plating solution having a liquid temperature of 27 ° C. as a stirring bath for 12 seconds at a current density of 1 A / dm 2. By electrolysis, the gray cobalt sulfate plating layer (thickness conversion 268 mg / m <2>) was formed. At this time, the cobalt ion concentration in the solution was not particularly adjusted. This is because the adjustment of the metal ion concentration is unnecessary because it is a short time electrolysis. The form of the formed cobalt sulfate plating layer is observed as shown in FIG. 11 and FIG. 12.

As a step (b), the pure water is sufficiently showered and washed, and the surface-treated copper foil having a gray-treated surface of very good color tone is blown out by keeping moisture for 4 seconds in a drying furnace having an atmospheric temperature of 150 ° C with a heater. 1b). In addition, between each process mentioned above, the water washing process by the pure water for 15 second is provided in principle, and the carry-in of a pretreatment process solution is prevented.

<Physical properties of surface-treated copper foil>

When the cross section of the surface-treated copper foil provided with the graying process surface obtained through the above process was observed with the FIB apparatus, the cross section as shown in FIG. 3 was obtained, and the cross-sectional height of the said graying process surface is 78 nm, The L value in the Lab color system of the graying process surface was 40, and glossiness [Gs (60 degrees)] was 2.6. In addition, color unevenness was not seen on the grayed-out surface, and powder dropping was not confirmed in the tape test in which the adhesive tape was attached to the surface and pulled off.

In addition, it was judged whether the grayed process surface of the obtained surface-treated copper foil was processed into the electromagnetic wave shielding mesh for plasma displays, and when it became black when it became transparent. The black density of the gray-treated surface before forming a transparent resin film was 0.9, and as a result of evaluating by the alternative method similar to Example 1, the gray-treated surface was observed as black with a black density of 1.5.

<Production of electromagnetic wave shielding mesh for plasma display>

In the same manner as in the first example, an electromagnetic wave shielding conductive mesh was fabricated using the obtained surface-treated copper foil. As a result, there was no problem in the etching operation, no etching residue, and very good etching was performed.

9th Example

In this embodiment, as shown in Fig. 7, a second surface-treated copper foil 1d having a zinc-cobalt alloy layer as a rust-preventing layer is produced, and the electromagnetic shielding conductive mesh shape is experimentally tested by an etching method. It was prepared to confirm the etching performance. Therefore, since it is common to 7th Example until the graying process layer by a cobalt sulfate plating layer is formed, only rust prevention process conditions are demonstrated. In addition, the conversion thickness of the gray cobalt sulfate plating layer was 268 mg / m <2> similarly to Example 7.

Here, the zinc-cobalt alloy layer was formed on both surfaces of the copper foil by which the formation of the gray cobalt sulfate plating layer was finished on one surface of the seventh example, under the same conditions as in the fourth embodiment. As in the first embodiment, the pure water was sufficiently showered and washed, the heater was kept for 4 seconds in a drying furnace having an ambient temperature of 150 ° C. with a heater to blow off moisture, and the surface treatment was provided with a grayed surface of very good color tone. Copper foil (1d) was obtained. On the other hand, between each process mentioned above, the washing | cleaning process by the pure water for 15 second is provided in principle, and the carry-in of the solution of a pretreatment process is prevented.

<Physical properties of surface-treated copper foil>

When the cross section of the surface-treated copper foil provided with the graying process surface obtained through the above process was observed with the FIB apparatus, the cross section as shown in FIG. 3 was obtained, and the cross-sectional height of the said graying process surface is 80 nm, The L value in the Lab color system of the graying process surface was 41, and glossiness [Gs (60 degrees)] was 2.4. In addition, color unevenness was not seen on the grayed-out surface, and powder fall-off in the tape test which stuck and peeled off the adhesive tape on the said surface was not confirmed.

In addition, it was judged whether the grayed process surface of the obtained surface-treated copper foil was processed into the electromagnetic wave shielding mesh for plasma displays, and when it became black when it became transparent. The black density of the gray-treated surface before forming a transparent resin film was 0.9, and as a result of evaluating by the alternative method similar to Example 1, the gray-treated surface was observed as black with a black density of 1.5.

<Production of electromagnetic wave shielding mesh for plasma display>

In the same manner as in the first example, an electromagnetic wave shielding conductive mesh was fabricated using the obtained surface-treated copper foil. As a result, there was no problem in the etching operation, no etching residue, and very good etching was performed.

Tenth embodiment

This embodiment manufactures the 2nd surface treatment copper foil 1f provided with the zinc-cobalt alloy layer and the chromate treatment layer as an antirust process layer as shown in FIG. 9, and the electromagnetic wave shielding conductive mesh shape is etched. Experimentally prepared to confirm the etching performance. Therefore, since it is common to 7th Example until the graying process layer by a cobalt sulfate plating layer is formed, only rust prevention process conditions are demonstrated. In addition, the conversion thickness of the gray cobalt sulfate plating layer is 270 mg / m <2> similarly to Example 7.

In the formation of the antirust treatment layer, a zinc cobalt alloy layer was formed on both surfaces using a zinc-cobalt alloy plating solution, and the same chromate treatment as that in the fifth embodiment was performed on both surfaces.

When the formation of the chromate layer is completed, the pure water is sufficiently showered and washed, the heater is kept for 4 seconds in a drying furnace having an atmospheric temperature of 150 ° C. with an electric heater to blow off moisture, and the grayed surface having a very good color tone is provided. Surface-treated copper foil (1f) was obtained. In addition, between each process mentioned above, the water washing process by the pure water for 15 second is provided in principle, and the carry-in of a pretreatment process solution is prevented.

<Physical properties of surface-treated copper foil>

When the cross section of the surface-treated copper foil provided with the graying process surface obtained through the above process was observed with the FIB apparatus, the cross section as shown in FIG. 3 was obtained, and the cross-sectional height of the said graying process surface is 78 nm, L value in the Lab colorimeter of the graying process surface was 40, and glossiness [Gs (60 degrees)] was 2.4. In addition, color unevenness was not seen on the grayed-out surface, and powder fall-off in the tape test which stuck and peeled off the adhesive tape on the said surface was not confirmed.

In addition, it was judged whether the grayed process surface of the obtained surface-treated copper foil was processed into the electromagnetic wave shielding mesh for plasma displays, and when it became black when it became transparent. The black density of the gray-treated surface before forming a transparent resin film was 0.9, and as a result of evaluating by the alternative method similar to Example 1, the gray-treated surface was observed as black with a black density of 1.6.

<Production of electromagnetic wave shielding mesh for plasma display>

In the same manner as in the first example, an electromagnetic wave shielding conductive mesh was fabricated using the obtained surface-treated copper foil. As a result, even if the antirust process layer existed, there was no problem in the etching operation, there was no etching residue, and very good etching was performed.

The surface-treated copper foil provided with the graying process surface which concerns on this invention has no stain of the graying process surface, and also there is no powder fall off from the said surface, Moreover, the etching process using a normal copper etching liquid is possible, and a plasma display By using it for the electromagnetic wave shielding conductive mesh of the front panel of a panel, formation of the high quality black mask without a color unevenness is attained. Moreover, if supply as a surface-treated copper foil provided with the graying process surface is possible, the blackening process process in the manufacturing process of a front panel will be possible. Moreover, the surface-treated copper foil provided with the graying process surface can apply the surface treatment process of the conventional copper foil by employ | adopting the manufacturing method mentioned above, and does not require a new manufacturing facility. Therefore, since a product without high quality color unevenness can be manufactured with a high product yield, production cost can be reduced.

Claims (20)

As a surface-treated copper foil provided with the graying process surface on the rough surface of an electrolytic copper foil, The graying treatment surface is a cobalt sulfate plating layer having a weight thickness of 200 mg / m 2 to 350 mg / m 2 provided on one surface of the copper foil layer, and the cross-sectional height of the graying treatment surface is 200 nm or less. Copper foil. The method of claim 1, The surface-treated copper foil which is equipped with the antirust process layer in the said grayening process surface. The method of claim 2, The antirust process layer is surface-treated copper foil using zinc or a zinc alloy. The method of claim 2, The antirust process layer is a surface-treated copper foil provided with the layer formed using zinc or a zinc alloy, and the graying process surface which consists of a chromate process layer. The method of claim 1, Surface treatment copper foil whose L value in a Lab color system is 43 or less in the said grayening process surface. The method of claim 1, The said grayening process surface formed the said grayation process surface in the rough surface of an electrolytic copper foil, and the surface-treated copper foil whose glossiness [Gs (60 degrees)] is 10 or less. The method of claim 1, The said grayening process surface is surface-treated copper foil whose black density is 0.7-1.2. The method of claim 1, The said surface treatment copper foil which can be visually recognized as black, when the said grayening process surface closely arranges the transparent resin film on the surface. The method of claim 1, The surface-treated copper foil whose black density | concentration when providing a transparent resin film in a grayening process surface is 1.2 or more. A manufacturing method of the surface-treated copper foil provided with the graying process surface, Comprising: The process of the following a) and b), The manufacturing method of the surface-treated copper foil characterized by the above-mentioned. a) 4 A / dm <2> or less using the stirring bath of the cobalt sulfate plating liquid which contains 10 g / l-40 g / l of cobalt sulfate (7-hydrate) in the rough surface of copper foil, and made pH more than 4.0 and liquid temperature 30 degrees C or less. Electrolysis at a current density of to form a gray cobalt sulfate plating layer. b) then washed with water and dried. The manufacturing method of the surface-treated copper foil provided with the graying process surface provided with the antirust process layer, Comprising: The manufacturing method of the surface-treated copper foil characterized by including the process of the following a) -c). a) Cobalt sulfate plating liquid containing 10 g / l-40 g / l of cobalt sulfate (7-hydrate) in the rough surface of copper foil, and using pH as 4.0 or more and 30 degrees C or less of liquid temperature as a stirring bath, 4 A / dm <2> or less Electrolysis at a current density of to form a gray cobalt sulfate plating layer. b) An antirust process layer is formed on both surfaces or one side of the copper foil in which the gray cobalt sulfate plating layer was formed. c) then washed with water and dried. The electromagnetic wave shielding conductive mesh for front panels of the plasma display formed using the surface-treated copper foil provided with the graying process surface of Claim 1. The electromagnetic wave shielding conductive mesh for front panels of the plasma display formed using the surface-treated copper foil provided with the graying process surface of Claim 2. The electromagnetic wave shielding conductive mesh for the front panel of the plasma display formed using the surface-treated copper foil provided with the graying process surface of Claim 3. The electromagnetic wave shielding conductive mesh for the front panel of the plasma display formed using the surface-treated copper foil provided with the graying process surface of Claim 4. The electromagnetic wave shielding conductive mesh for the front panel of the plasma display formed using the surface-treated copper foil provided with the graying process surface of Claim 5. The electromagnetic wave shielding conductive mesh for the front panel of the plasma display formed using the surface-treated copper foil provided with the graying process surface of Claim 6. The electromagnetic wave shielding conductive mesh for the front panel of the plasma display formed using the surface-treated copper foil provided with the graying process surface of Claim 7. The electromagnetic wave shielding conductive mesh for the front panel of the plasma display formed using the surface-treated copper foil provided with the graying process surface of Claim 8. The electromagnetic wave shielding conductive mesh for the front panel of the plasma display formed using the surface-treated copper foil provided with the graying process surface of Claim 9.

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