KR101003317B1 - Emi shielding conductive thin film using dry-wet plating and method for preparing the same - Google Patents

Abstract

PURPOSE: A conductive film is provided to improve the coating adhesive force and uniformity with a base material by using a dry plating process and a wet plating process. CONSTITUTION: A non-conductive thin film base material(10) has the thickness of 1um to 50um. A first plating layer(20A,20B) is formed in both sides of the non-conductive thin film base material. The first plating layer is formed by plating a first metal. A second plating layer(30A,30B) is formed on the first plating layer. The second plating layer is formed by plating a second metal through a wet plating process. A third plating layer(40A,40B) is formed on the second plating layer. The third plating layer is formed by plating a third metal through the wet plating process.

Description

Conductive thin film for electromagnetic shielding using dry-wet fusion process {EMI SHIELDING CONDUCTIVE THIN FILM USING DRY-WET PLATING AND METHOD FOR PREPARING THE SAME}

The present invention relates to a conductive thin film for electromagnetic shielding using a dry-wet fusion process and a method of manufacturing the same. More specifically, the present invention has excellent conductivity along with the flexibility of the base metal, and can simplify the complex plating process, as well as for electromagnetic shielding using a dry-wet fusion process that can minimize the wastewater discharged from the wet process. It relates to a conductive thin film and a method of manufacturing the same.

In general, electromagnetic waves are generally referred to as noise phenomena generated by electrostatic discharge, and are generated in internal circuits of various electronic devices and radiated to the outside through the air or conducted through power lines. These electromagnetic waves are known to not only cause noise and malfunction of surrounding components or devices, but also have harmful effects on the human body. Recently, as the circuit becomes complicated due to the light and thin and digitalization of electronic devices, the possibility of electromagnetic wave is rapidly increasing, and the regulation of electromagnetic waves is strengthened not only in advanced countries but also in Korea.

Various materials are used for the purpose of protecting an apparatus and a human body from the shielding material of the electromagnetic wave from the generation | occurrence | production sources of electronics, an electric circuit component, an apparatus, etc., or the electromagnetic wave from an unspecified generation | generation source. For example, a method of processing and using a metal into a network, a method of processing and using a metal wire, a resin containing a metal powder, a coating method, a coating method, a plating method, a resin containing a metal powder, a rubber sheet, and the like. The method of using the material processed into the phase and line shape, the method of using the material wound up the metal foil etc. to the fiber, the method of using the material which plated the fiber etc. are used. In particular, when the shielding material is in the form of a sheet, it is widely used because of its convenience in processing, assembling, poring and the like.

Conventionally, electroless copper plating after polyester fiber or the like has been widely used.

BACKGROUND ART The electromagnetic wave shielding material processed by the wet plating method has been developed for a long time. For example, Japanese Patent Laid-Open No. 62-18799 discloses a nonwoven fabric containing metal fibers. Japanese Patent Laid-Open No. 2-237100 mentions an electromagnetic wave shielding material of paper in which an electroless plating layer is formed, and Japanese Patent Laid-Open No. Hei 4-109698 discloses a nonwoven fabric for interior building materials using fibers coated with silver. In addition, Japanese Patent Application Laid-Open No. 4-153034 discloses an interior material using silver-plated synthetic fibers coated with silver by an electroless plating method, and Japanese Patent Laid-Open No. 5-48289 discloses at least 10 weights of short metal fibers or metal plated short fibers. An electromagnetic wave shielding material composed of a non-oriented nonwoven fabric containing% is disclosed. On the other hand, Japanese Patent Application Laid-Open No. Hei 5-121893 contains at least 10 g / m 2 or more of silver plated synthetic fibers coated with silver by an electroless plating method, and 10 to 50% by weight of the non-plated fibers has a low melting point of 100 ° C to 190 ° C. It refers to an electromagnetic shielding sheet composed of a fiber wave which is a mixed fiber with synthetic fibers, wherein a thermoplastic resin sheet is integrally laminated on one or both sides of a nonwoven fabric sheet interlaced between fibers made by weaving yarn. Korean Patent Application No. 7-101789 has a tensile strength of 100 g / cm² or more for weft and incline, does not invade acids or alkalies, and furthermore, the electrolytic plating catalyst liquid is applied to a paper having absorbency and dried. Then, the electromagnetic wave shielding member is characterized by depositing and forming an electroless plating layer on the surface and face of the above paper by performing electroless plating. Japanese Patent Application Laid-Open No. 7-259291 discloses an electromagnetic wave shielding panel, wherein an electromagnetic wave shielding sheet formed by applying metal plating to a nonwoven fabric is attached to a board building material.

By the way, such a technology is only a polyester or acrylic-based refined / reduced treatment as a base material, and more than 20 many processes, including processes such as etching, catalysis, activation treatment, and various washing, pickling, drying, etc. This is necessary and the plating process is complicated. In addition, there is a problem of increasing manufacturing costs, such as excessive environmental costs due to waste and waste water caused by the disposal of various nonferrous metals and catalyst noble metals in the liquid, as well as dropping of metal particles generated during processing into the required shape. This may cause malfunction of electronic and communication equipment.

In addition, when only electroless plating is used, plating adhesion and uniformity with the polymer sheet, which is a base material, are easily peeled off, which results in a relatively high surface resistance and vertical resistance. In addition, since the electroless plating process requires a large amount of water, there is a fear that a large amount of wastewater is generated to amplify environmental pollution.

One object of the present invention is to provide an electroconductive thin film for electromagnetic shielding excellent in the adhesion and uniformity of the base material and its manufacturing method.

Another object of the present invention is to provide a conductive thin film for electromagnetic shielding excellent in electrical conductivity in a horizontal direction and a vertical direction (thickness direction) and a method of manufacturing the same.

Still another object of the present invention is to provide a conductive thin film for electromagnetic wave shielding which minimizes the generation of waste water and waste gas and a method of manufacturing the same.

Another object of the present invention is not only to have an ultra-thin film, but also excellent in flexibility, computer and mobile phone parts, magnetic field shielding and absorbing body, LCD frame cushion, shielding material for radiation shielding, interior and exterior materials for building, electrical wire, shielding and electric storage material, electromagnetic wave The present invention provides a conductive thin film for electromagnetic shielding and a method of manufacturing the same that can be applied to barrier clothing, protective equipment, masks and gloves.

Still another object of the present invention is to provide a conductive thin film for electromagnetic shielding and a method of manufacturing the same, which can simplify complex wet plating processes and be applied to various substrates.

Still another object of the present invention is to provide a conductive thin film for electromagnetic shielding and a method of manufacturing the same, which are low in manufacturing cost, maintain an equal quality, and are capable of mass production.

Technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

One aspect of the invention relates to a conductive thin film for electromagnetic shielding. The conductive thin film is a non-conductive thin film base material; A first plating layer in contact with the non-conductive thin film base material and formed by dry plating a first metal; A second plating layer in contact with the first plating layer and formed by wet plating of a second metal; And a third plating layer in contact with the second plating layer and formed by wet plating of a third metal.

In embodiments, the non-conductive thin film base material may be a thin film, woven fabric, or nonwoven fabric selected from the group consisting of polyolefin, polyester, polyalkyl (meth) acrylate, polystyrene, polyamide, and polycarbonate.

In an embodiment, the non-conductive thin film base material may have a hole having an average diameter of 2 to 50 μm and an average density of 200 to 2000 particles / cm 2.

The base material of the non-conductive thin film may be a thin film material having a thickness of 1 to 50 μm, preferably 10 to 30 μm.

The first metal may be selected from the group consisting of copper, nickel, cobalt, tin and Fe + Ni.

The dry plating may include physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods such as vacuum deposition, ion plating, and sputtering.

The second metal may be selected from the group consisting of copper, cobalt, tin and Fe + Ni.

The wet plating may be electroplating or electroless plating.

The third metal may be selected from the group consisting of metals such as nickel, copper, tin, silver, gold, cobalt, black nickel, platinum, palladium and chromium.

In another embodiment, a polymer resin film may be formed on the surface of the third plating layer.

The polymer resin film may be selected from one or more of an olefin resin, a urethane resin, an acrylic resin, and an ester resin.

The conductive thin film may have a surface resistance (thickness direction) for a specimen having a size of 3 mm 3 mm 2 in a range of 0.001 to 0.05 Ω.

Another aspect of the invention relates to a method for manufacturing a conductive thin film for electromagnetic shielding. The method comprises dry plating a first metal selected from the group consisting of copper, nickel, cobalt, tin and Fe + Ni on a non-conductive thin film base material to form a first plating layer; Forming a second plating layer by wet plating a second metal selected from the group consisting of copper, cobalt, tin, and Fe + Ni on the first plating layer; And wet plating a third metal selected from the group consisting of nickel, copper, tin, silver, gold, cobalt, black nickel, platinum, palladium, and chromium in the second plating layer to form a third plating layer.

The dry plating includes physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods such as vacuum deposition, ion plating and sputtering, and the wet plating is characterized in that the electroplating or electroless plating.

In an embodiment, the method may further include forming a polymer resin film on the surface of the plated conductive thin film.

The present invention has excellent plating adhesion and uniformity with the base material, has excellent electrical conductivity in the horizontal direction and the vertical direction (thickness direction), minimizes the generation of waste water and waste gas, is environmentally friendly, has an ultra thin film, and has excellent flexibility. Complex wet plating, applicable to computer and mobile phone parts, magnetic field shielding and absorbing material, LCD frame cushion, shielding material for radiation shielding, interior and exterior materials for building, electric wire material, shielding and shearing material, electromagnetic shielding clothing, protective equipment, masks and gloves The present invention can simplify the process and be applied to various substrates, has a low manufacturing cost, maintains uniform quality, and has an effect of providing an electroconductive thin film for electromagnetic shielding and a method of manufacturing the same.

Electromagnetic shielding thin film of the present invention is a non-conductive thin film base material; A first plating layer in contact with the non-conductive thin film base material and formed by dry plating a first metal; A second plating layer in contact with the first plating layer and formed by wet plating of a second metal; And a third plating layer in contact with the second plating layer and formed by wet plating of a third metal.

1 is a schematic cross-sectional view of a conductive thin film of the present invention. As shown in the drawing, the conductive thin film is a non-conductive thin film base material 10; First plating layers 20A and 20B in contact with the non-conductive thin film base material; Second plating layers 30A and 30B in contact with the first plating layer; And a third plating layer 40A, 40B in contact with the second plating layer.

The non-conductive thin film base material 10 is a material that is not substantially conductive, and the purpose of the present invention is to impart conductivity to the non-conductive base material, so there is no particular limitation on conductivity. In addition, in the prior art, only a polyester-based or acrylic-based application is possible, but the present invention is not particularly limited to the thin film base material, and any substrate may impart conductivity.

In a specific embodiment, the non-conductive thin film base material may be a thin film, a woven fabric, or a nonwoven fabric. Preferably, the non-conductive thin film base material is polypropylene including polypropylene, polyethylene, LDPE, LLDPE, polyester including PET, PBT, polyalkyl (meth) acrylate including PMMA, polystyrene, polyamide And polycarbonates and the like can be used. These may be a single base material or two or more types of mixed base materials.

The non-conductive thin film base material may be an ultra-thin film having a thickness of 1 to 50 ㎛, preferably 10 to 30 ㎛.

In addition, the non-conductive thin film base material has an average diameter of 2 to 50 ㎛, a hole having an average density of 200 ~ 2000 number / cm 2 may be formed.

First plating layers 20A and 20B are formed on the surface of the non-conductive thin film base material 10. The first plating layers 20A and 20B are formed by dry plating a first metal selected from the group consisting of copper, nickel, cobalt, tin, and Fe + Ni. Of these, nickel is preferred.

The dry plating may include physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods such as vacuum deposition, ion plating and sputtering, preferably by using vacuum and plasma.

In a specific embodiment, the vacuum plasma method is a pre-treatment of bombardment cleaning with argon ions before the formation of the dry-plated thin film and at a initial vacuum of 10-6 Torr, depending on the base material, plating type and target properties, 10-5 to 10 Dry plating such as sputtering and ion plating can be performed by vacuum deposition or applying a bias voltage at -2 Torr to generate a plasma.

The first plating layers 20A and 20B formed by such dry plating may have a thickness of 1 to 5 μm.

After the first plating layers 20A and 20B are formed, the second plating layers 30A and 30B are formed on the first plating layers 20A and 20B.

The second plating layers 30A and 30B are formed by wet plating a second metal selected from the group consisting of copper, cobalt, tin, and Fe + Ni. Among these, copper is preferable.

Electrolytic plating or electroplating may be used as the wet plating, and the plating method may be easily performed by those skilled in the art. Among these, electroless copper plating is preferable.

In an embodiment, the plating bath applied to the electroless copper plating may include at least one copper salt, at least one reducing agent, and at least one complexing agent. Copper sulfate, copper chloride, and the like are suitably used as copper salts for supplying copper ions, and formaldehyde, hydrazine tetrahydroborate, dimethylamine borane, glyoxylic acid, etc., as a reducing agent, and ethylenediaminetetraacetic acid, ethylenetri Aminetetraacetic acid, lotel salt, glycerol, mesoerythritol, adonitol, D-mannitol, D-isorbitol, zolitol, iminodiacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, 1,3- Diaminopropane-2-oltetraacetic acid, glytoletherdiaminetetraacetic acid, triethanolamine, triisopropanolamine, nitrotriacetic acid, tetrakis (2-hydroxyethyl), ethylenediamine, tetrakis (2-hydroxypropyl) , Ethylenetriamine and the like can be used.

In a preferred embodiment, the electroless copper plating tank may include copper sulfate 3.0 to 4.5 g / l, caustic soda 8 to 10 g / l, and formalin 4.0 to 5.5 g / l.

After the second plating layers 30A and 30B are formed, the third plating layers 40A and 40B are formed on the second plating layers 30A and 30B.

The third plating layers 40A and 40B are formed by wet plating a third metal selected from the group consisting of nickel, copper, tin, silver, gold, cobalt, black nickel, platinum, palladium and chromium.

Electrolytic plating or electroplating may be used as the wet plating, and the plating method may be easily performed by those skilled in the art. Among these, electroless nickel plating is preferable.

In an embodiment, the electroless nickel plating bath may include 20-30 g / l nickel sulfate, 20-30 g / l sodium hypophosphite, and 30-45 g / l sodium citrate.

In another embodiment, a polymer resin film (not shown) may be formed on the surface of the third plating layer. The polymer resin film may be a polymer synthetic resin such as olefin resin, urethane resin, acrylic resin, ester resin, etc., but is not necessarily limited thereto. Among them, urethane resins are preferable.

The polymer resin film may be formed by coating or depositing. In a preferred embodiment it can be formed by depositing the plated polymer foam sheet in an aqueous urethane liquid. When the polymer resin film is formed on the surface of the plated polymer foam sheet as described above, corrosion and discoloration of the metal may be prevented, thereby increasing durability and reliability.

The conductive thin film of the present invention prepared as described above has excellent conductivity with a surface resistance (thickness direction) of 0.001 to 0.05 Ω, preferably 0.01 to 0.03 Ω, for a specimen having a size of 3ⅹ3 mm2.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Example 1

Nickel was sputtered on the PET thin film having a thickness of 10 μm by a dry plating method to form a first plating layer having a thickness of 1 μm. The thin film on which the first plating layer was formed was deposited in an electroless copper plating bath of copper sulfate 4g / l, caustic soda 9g / l, and formalin 5g / l to form a copper plating layer as a second plating layer. Subsequently, a nickel plating layer as a third plating layer was formed by depositing an electroless nickel plating bath in which nickel sulfate 25g / l, sodium hypophosphite 25g / l, and sodium citrate 35g / l were mixed to prepare a conductive thin film. The conductive thin film was cut into 25ⅹ25 mm2 and 3ⅹ3 mm2 sizes to prepare a sample, and the vertical conductivity (thickness direction) was measured under a 1 kg load using a HIOKI 3540 mΩ Hi tester (using a gold plated brass probe). . 15 measurements were taken for each sample and the average value was obtained.

Comparative Example 1

Example 1 except that the nickel plating layer was formed by a wet electrolytic method by depositing in an electroless nickel plating bath in which nickel sulfate 25g / l, sodium hypophosphite 25g / l, and sodium citrate 35g / l were mixed when the first plating layer was formed. Was performed in the same manner. The vertical conductivity results are shown in Table 1 below.

Comparative Example 2

The PET thin film having a thickness of 10 μm was passed through an ultrasonic washing tank to remove contaminants remaining in the thin film, followed by an etching bath with a caustic soda at a temperature of 75 to 100 ° C. at a concentration of 10 to 20%. After removing the caustic soda residue in the sheet, palladium ions in the sheet were adsorbed through a catalyst tank of a mixture of palladium chloride and tin chloride. Then, to remove tin ions adsorbed together with paradium ions, only the paradium metal ions are formed in the thin film by passing through an activation tank of 10% sulfuric acid, nickel sulfate 25g / l, sodium hypophosphite 25g / l, A nickel plating layer was formed by immersing in an electroless nickel plating bath mixed with 35 g / l of sodium citrate, and then the second plating layer and the third plating layer were formed in the same manner as in Example 1. The vertical conductivity results are shown in Table 1 below.

Example 1 except that the nickel plating layer was formed by a wet electrolytic method by depositing in an electroless nickel plating bath in which nickel sulfate 25g / l, sodium hypophosphite 25g / l, and sodium citrate 35g / l were mixed when the first plating layer was formed. Was performed in the same manner. The vertical conductivity results are shown in Table 1 below.

25ⅹ25 mm2 3ⅹ3 mm2 Example 1 Comparative Example 1 Comparative Example 2 Example 1 Comparative Example 1 Comparative Example 2 Resistance (Ω) 0.04 1.02 0.05 0.031 0.86 0.042

As shown in Table 1, it can be seen that Example 1 has a significantly lower resistance value than Comparative Example 1 plated without pretreatment. In addition, it can be seen that the resistance value of the embodiment is lower than that of Comparative Example 2, which has been subjected to the pretreatment process, and the present invention has excellent conductivity without undergoing a complicated pretreatment process, and is expected to reduce the generation of waste water since the pretreatment process is not performed. .

Simple modifications and variations of the present invention can be easily made by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

1 is a schematic cross-sectional view of a conductive thin film of the present invention.

<Explanation of symbols on main parts of the drawings>

              10: non-conductive thin film base material 20A, 20B: first plating layer

        30A, 30B: Second Plating Layer 40A, 40B: Third Plating Layer

Claims (15)

A non-conductive thin film base material with holes formed; A first plating layer in contact with the non-conductive thin film base material and formed by dry plating a first metal; A second plating layer in contact with the first plating layer and formed by wet plating of a second metal; And A third plating layer in contact with the second plating layer and formed by wet plating of a third metal; Electroconductive thin film for electromagnetic shielding using a dry-wet fusion process, characterized in that consisting of. According to claim 1, wherein the non-conductive thin film base material is a thin film, woven or non-woven fabric selected from the group consisting of polyolefin, polyester, polyalkyl acrylate, polyalkyl methacrylate, polystyrene, polyamide and polycarbonate A conductive thin film characterized in that. The conductive thin film according to claim 1, wherein the non-conductive thin film base material has an average diameter of 2 to 50 µm and a hole having an average density of 200 to 2000 pieces / cm ² is formed. The conductive thin film of claim 1, wherein the non-conductive thin film base material has a thickness of 1 to 50 μm. The conductive thin film of claim 1, wherein the first metal is a metal or an alloy selected from the group consisting of copper, nickel, cobalt, tin, and Fe + Ni. The conductive thin film of claim 1, wherein the dry plating is one of physical vapor deposition (PVD) and chemical vapor deposition (CVD) including vacuum deposition, ion plating, and sputtering. The conductive thin film of claim 1, wherein the second metal is a metal or an alloy selected from the group consisting of copper, cobalt, tin, and Fe + Ni. The conductive thin film of claim 1, wherein the wet plating is electroplating or electroless plating. The conductive thin film of claim 1, wherein the third metal is a metal or an alloy selected from the group consisting of nickel, copper, tin, silver, gold, cobalt, black nickel, platinum, palladium, and chromium. . The conductive thin film according to claim 1, wherein a polymer resin film is formed on the surface of the third plating layer. The conductive thin film of claim 10, wherein the polymer resin film is made of a polymer synthetic resin selected from at least one of an olefin resin, a urethane resin, an acrylic resin, and an ester resin. The conductive thin film according to any one of claims 1 to 11, wherein the conductive thin film has a surface resistance in the thickness direction of a specimen having a size of 3 mm 3 mm in a range of 0.001 to 0.05 Ω. Forming a first plating layer by dry plating a first metal, which is a metal or an alloy, selected from the group consisting of copper, nickel, cobalt, tin, and Fe + Ni on the hole-formed nonconductive thin film base material; Forming a second plating layer by wet plating a second metal, which is a metal or an alloy, selected from the group consisting of copper, cobalt, tin, and Fe + Ni on the first plating layer; And Forming a third plating layer by wet plating a third metal, which is a metal or an alloy, selected from the group consisting of nickel, copper, tin, silver, gold, cobalt, black nickel, platinum, palladium, and chromium in the second plating layer. ; Method for producing a conductive thin film for electromagnetic shielding using a dry-wet fusion process, characterized in that it comprises a step. The method of claim 13, wherein the dry plating is one of physical vapor deposition (PVD) and chemical vapor deposition (CVD) including vacuum deposition, ion plating, and sputtering, and the wet plating is electroplating or electroless plating. Method for producing a conductive thin film, characterized in that. The method of claim 13, further comprising forming a polymer resin film on a surface of the plated conductive thin film.

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