KR100992569B1 - An electroconductive ultra thin tape for shielding electromagnetic wave, and a method for production of the same - Google Patents

Abstract

The present invention relates to an ultra-thin conductive tape for electromagnetic wave shielding and a method of manufacturing the same. More specifically, the present invention is a vacuum and washing treatment using a low temperature plasma apparatus, and then sputter etched, perforated by a perforator for up and down energization, and then physically interfacially treated by plasma etching or corona discharge etching, and electrically conductive. After an excellent metal is electrolytically and / or electroless plated, the present invention relates to an ultra-thin conductive tape for shielding electromagnetic waves produced by applying a conductive adhesive on one or both surfaces thereof, and a method of manufacturing the same.

The ultra-thin conductive tape for electromagnetic wave shielding according to the present invention is remarkably excellent in electromagnetic shielding rate, surface resistance, vertical (vertical) resistance, adhesive strength, uniform thickness characteristics, etc., to apply the ultra-thin conductive tape to a compact product such as a mobile phone It is very useful, it does not generate any burr, so there is no electrical short problem due to the burr, and it has superior material cost competitiveness and excellent surface smoothness and thickness uniformity compared to substrates for conventional conductive tapes. It has advantages

Electromagnetic shielding, ultra thin insulating film substrate, ultra thin conductive film substrate, conductive adhesive, nickel plating, copper plating, hole, perforation, low temperature plasma, corona discharge etching, vacuum, cleaning, sputter etching, plasma etching ( plasma ethcing), interfacial treatment, electroless / electrolytic plating.

Description

Ultra-thin conductive tape for electromagnetic wave shield and manufacturing method thereof {AN ELECTROCONDUCTIVE ULTRA THIN TAPE FOR SHIELDING ELECTROMAGNETIC WAVE, AND A METHOD FOR PRODUCTION OF THE SAME}

The present invention relates to an ultra-thin conductive tape for electromagnetic wave shielding and a method of manufacturing the same. More specifically, the present invention is physically interfacially treated by sputter etching and plasma etching or corona discharge etching after vacuuming and washing using a low temperature plasma apparatus, and perforated by perforators for up and down conduction, and then the electrical conductivity is The present invention relates to an ultra-thin conductive tape for electromagnetic wave shielding, in which a conductive adhesive is applied to one or both surfaces after an excellent metal is electrolytically and / or electroless plated, thereby improving the vertical conduction and electromagnetic shielding performance.

Conventional thin film conductive fabrics are used to produce a thin film conductive fabric by pressing a nonwoven fabric or woven fiber into a thin film and then electrolytic or electroless plating, but these fabrics have a limitation in thinning the thickness and also loosening the woven fiber. There is a problem with Burr. Therefore, through the present invention, to achieve ultra-thin film and to improve the problems of burr generation, surface smoothness and thickness variation.

Meanwhile, ultrasonic cleaning is performed in a caustic soda chemical bath to impart hydrophilicity to increase the plating area, and to improve the adhesion between the insulating polymer film and the metal plating interface and to prevent the metal peeling phenomenon. However, the chemical interface treatment alone has a weak adhesion to prevent the metal peeling phenomenon, which makes it difficult to realize products with uniform electrical characteristics, and conductive patterns formed on printed circuit boards (PCB) inside electronic and communication devices. However, there is a problem of generating an electrical short of the electronic component.

Accordingly, the present inventors have diligently studied, and then performing the physical interface treatment by sputter etching and plasma etching or corona discharge etching after vacuum and cleaning the insulating polymer film using a low temperature plasma apparatus, or after chemical physical treatment By performing the interfacial treatment, it has been found that the above-mentioned problems of the prior art can be solved.

An object of the present invention is to provide an ultra-thin conductive tape for shielding electromagnetic waves, which is remarkably excellent in electromagnetic shielding rate, surface resistance, top and bottom (vertical) resistance, adhesive force, thickness variation, surface smoothness, and burr problems.

In addition, the present invention fundamentally realizes a product having uniform electrical characteristics by using a film free of burrs and unfolding phenomenon, and thus, a conductive pattern or electronic component formed on a printed circuit board (PCB) inside an electronic and communication device. It is an object of the present invention to provide a method for producing an ultra-thin conductive tape for shielding electromagnetic waves that can prevent the occurrence of an electrical short.

According to the present invention, after the vacuum and cleaning process using a low temperature plasma apparatus, the physical interface treatment is performed by sputter etching and plasma etching or corona discharge etching, and the conductive adhesive is coated on one or both sides after the metal having excellent electrical conductivity is plated. An ultra-thin conductive tape for electromagnetic wave shield on which a substrate is laminated, comprising: an ultra-thin insulating film substrate layer 10 having holes 30 perforated at regular intervals; One or more plating layers 20 surrounded by the perforated holes 30 and surrounding the ultra-thin insulating film base layer 10, wherein a metal having excellent electrical conductivity is plated by electrolytic, electroless, substitution, vacuum deposition, or sputtering. ); And it provides an electromagnetic shielding ultra-thin conductive tape comprising a conductive adhesive layer 40 attached to one or both sides.

Interfacial treatment prevents metal drop phenomenon, plating peeling or bubble formation, unevenness of glossiness such as stain, cloudiness, unevenness of plating or pit or crack of plating film (brittle), and the like. It is performed for the purpose of strengthening the binding force of ions and the like. However, the conventional chemical interface treatment alone has a limitation in preventing the metal peeling phenomenon by improving the adhesion between the insulating polymer film and the metal plating interface, and it is difficult to realize a product having uniform electrical characteristics. It may cause the generation of a conductive pattern formed on a printed circuit board (PCB) or an electrical short of an electronic component. Therefore, the ultra-thin conductive film substrate for electromagnetic wave shield according to the present invention is characterized by physically interfacial treatment by sputter etching and plasma etching or corona discharge etching after vacuum and cleaning treatment using a low temperature plasma apparatus.

Meanwhile, the ultra-thin conductive film substrate for electromagnetic wave shielding according to the present invention may be chemically interfaced after physical interface treatment. The chemical interfacial treatment is performed by performing a process of caustic soda etching / ultrasound washing (improve hydrophilicity), washing with water, acid treatment (neutralization), washing with water, palladium catalysis (with palladium ion adsorption), washing with water, activation of sulfuric acid, washing with water and the like.

It is preferable that an insulating polymer film base material is a polyester film, a polyethyleneimide film, or a polyimide.

Examples of the conductive adhesive include acrylic, urethane, vinyl acetate, polyvinyl alcohol, polyvinyl, polyvinylacetate, polyamide, or polyethylene pressure sensitive adhesives, but any of those known in the art may be used. Do.

The ultra-thin conductive film has perforated holes at regular intervals, but the size of the perforated holes is not particularly limited, but is preferably 0.1 to 1.5 mm in consideration of the use and electrical properties of the final product.

It is preferable that the at least one plating layer is plated by electrolytic, electroless, substitutional, vacuum deposition or sputtering with a metal having excellent electrical conductivity selected from the group consisting of nickel, copper, gold, silver, tin and cobalt.

The ultra-thin conductive tape for electromagnetic shielding of the present invention has an electromagnetic shielding rate of more than 70 dB measured according to the ASTM D4935 method, a surface resistance of less than 50 mPa measured according to the ASTM D991 method, and an upper and lower measured according to the ASTM D991 method. (Vertical) resistance is less than 10 mPa.

In addition, the present invention is a method of manufacturing an ultra-thin conductive tape for electromagnetic wave shielding, the ultra-thin insulating film material is selected from the group consisting of polyester, polyethyleneimide, polyimide, etc. Washing; Physical interface treatment by sputter etching and plasma etching or corona discharge etching; Perforating at regular intervals; Plating an electroconductive metal selected from the group consisting of nickel, copper, gold, silver, tin and cobalt by electrolytic, electroless, substitutional, vacuum deposition or sputtering; And it provides a method comprising the step of forming a conductive adhesive layer on one or both sides.

In the vacuum and washing step using a low temperature plasma apparatus, the ultrathin insulation film perforated in the low temperature plasma apparatus is disposed, and the washing is repeated by injecting argon (Ar) gas of 40 to 200 sccm while maintaining a vacuum degree of 150 to 600 mTorr.

In the physical interface treatment step by sputter etching and plasma etching, sputter etching for 20 to 40 seconds while maintaining the composition ratio of oxygen (O ₂ ) gas: argon (Ar) gas in the low temperature plasma apparatus at 30 to 60 sccm: 30 sccm , Plasma etching for 30 seconds to 5 minutes using only 20-100 sccm of oxygen (O ₂ ) gas, and washing with argon (Ar) gas for etching or physical etching by a general method using a high voltage corona discharge device. You can also do

The size and spacing of the holes perforated in the ultrathin insulating film may vary depending on the intended use of the final product. If the diameter of the perforated hole is too large, the ratio of the area occupied by the perforated space becomes high, or if the spacing between the perforated holes becomes dense, the tensile strength as a conductive substrate during die cutting may drop. It is preferable to perforate the ultra-thin insulating film, but needle punching processing is also possible. The size of the hole is preferably 0.1 to 1.5 mm in consideration of the use of the product, the electrical characteristics and the ease of operation.

On the other hand, chemical interfacial treatment may be performed after the physical interfacial treatment step, which includes caustic soda etching / ultrasound washing (hydrophilicity), water washing, acid treatment (neutralization), water washing, palladium catalysis (palladium ion adsorption). , Water washing, sulfuric acid activation, washing with water and the like. For example, the physically interfacial ultrathin insulating film is passed through an etching bath at a concentration of 10 to 15% by weight of 80 ° C caustic soda, passed through a water bath, and neutralized under an aqueous solution of 15 to 25% by weight of hydrochloric acid at 50 to 70 ° C. do. Subsequently, a palladium catalyst bath composed of a mixture of palladium chloride and tin chloride was passed through to adsorb palladium ions onto the ultra-thin insulating film, followed by washing with water. It is deposited in a bath and washed with water to form only palladium ions in the ultra-thin insulating film.

Plating of a metal with excellent electrical conductivity selected from the group consisting of nickel, copper, gold, silver, tin and cobalt is preferably in an electrolytic, electroless, substitutional, vacuum deposition or sputtering manner, more preferably in an electroless manner. Can be done. For example, nickel-sulphate is deposited in an electroless nickel plating bath containing 25 to 35 g / l of nickel sulfate, 15 to 25 g / l of sodium hypophosphite and 35 to 45 g / l of sodium citrate to deposit nickel metal to deposit the surface of the ultra-thin insulating film surface and holes. A nickel plating layer was first formed in the hole and washed with water, followed by electroless copper plating in which copper sulfate was mixed with 3.5 to 4.5 g / l, caustic soda 8 to 12 g / l and formalin 5.5 to 6.0 g / l. It deposits in a bath, precipitates a copper metal, forms a copper plating layer secondaryly, and washes with water. Since copper is rapidly oxidized, nickel is deposited in an electroless nickel plating bath containing 25 to 35 g / l nickel sulfate, 15 to 25 g / l sodium hypophosphite, and 35 to 45 g / l sodium citrate to prevent oxidation. The plating layer is formed third and washed with water.

Examples of the conductive adhesive formed on one or both surfaces of the ultra-thin conductive substrate thus produced include acrylic, urethane, vinyl acetate, polyvinyl alcohol, polyvinyl, polyvinylacetate, polyamide, or polyethylene pressure sensitive adhesives. However, any of those known in the art may be used.

The ultra-thin conductive tape for electromagnetic wave shield according to the present invention is remarkably excellent in electromagnetic wave shielding rate, surface resistance, vertical and vertical (vertical) resistance, adhesive force, uniform thickness characteristics and the like.

In addition, according to the manufacturing method of the ultra-thin conductive tape according to the present invention, a conductive pattern or an electron formed on a printed circuit board (PCB) inside an electronic and communication device by preventing a metal peeling phenomenon and realizing a product having uniform electrical characteristics It is possible to fundamentally prevent the occurrence of electrical shorts in the parts.

Through the following examples will be described in more detail the present invention. However, the following examples are only for illustrating the present invention, and the scope of the present invention should not be construed as being limited to the following examples. Therefore, it will be understood by those skilled in the art that various modifications, modifications and applications of the following embodiments are possible within the scope of the technical idea derived from the matters described in the appended claims.

Example

The perforated ultra-thin insulating film was placed in a low temperature plasma apparatus, and washing was repeated by injecting about 100 sccm of argon (Ar) gas while maintaining a vacuum degree of about 500 mTorr. Subsequently, after sputter etching for about 30 seconds while maintaining the composition ratio of oxygen (O ₂ ) gas: argon (Ar) gas at 45 sccm: 30 sccm in the low temperature plasma apparatus, only 60 sccm of oxygen (O ₂ ) gas was used. Plasma etching was performed for about 2 minutes, washed with argon (Ar) gas, and etched, or by a corona discharge etching apparatus as one of general etching methods. Subsequently, holes were formed in the etched ultra-thin insulating film substrate at regular intervals to form holes of about 0.7 mm in size. The physical interface treated ultrathin insulating film substrate was passed through an etching bath at a concentration of 12% by weight of 80 ° C caustic soda, passed through a water bath, and neutralized and washed with water at a concentration of 20% by weight of 60 ° C hydrochloric acid. Thereafter, a palladium catalyst bath composed of a mixture of palladium chloride and tin chloride was passed through to adsorb palladium ions onto the ultra-thin insulating film substrate, followed by washing with water, followed by activation of 18 wt% sulfuric acid to remove tin ions adsorbed with palladium ions. It was deposited in a bath and washed with water to form only palladium ions in the ultra-thin insulating film substrate. Subsequently, nickel was deposited on an electroless nickel plating bath mixed with 30 g / l of nickel sulfate, 20 g / l of sodium hypophosphite and 40 g / l of sodium citrate to precipitate nickel metal to deposit nickel on the surface and hole of the ultra-thin insulating film substrate. After the plating layer was first formed and washed with water, the copper plating layer was deposited by depositing copper metal in an electroless copper plating bath mixed with copper sulfate 4.0 g / l, caustic soda 10 g / l and formalin 5.8 g / l for copper plating. It was formed secondarily and washed with water. Thereafter, a nickel plating layer was formed into a third layer and washed with water by dipping in an electroless nickel plating bath mixed with 30 g / l nickel sulfate, 20 g / l sodium hypophosphite and 40 g / l sodium citrate. Subsequently, the conductive tape for electromagnetic wave shielding was produced by forming an acrylic conductive adhesive layer on both surfaces or a cross section.

The ultra-thin conductive tape for electromagnetic shielding has an electromagnetic shielding rate of 84 dB measured according to the ASTM D4935 method, a surface resistance of 32 m ASTM measured according to the ASTM D991 method, and a vertical resistance (vertical) resistance measured according to the ASTM D991 method. It was 7.4 mPa.

1 is a cross-sectional view of an ultra-thin double-sided conductive tape for shielding electromagnetic waves according to a preferred embodiment of the present invention.

Figure 2 shows the perforated surface of the ultra-thin conductive tape for electromagnetic wave shield according to a preferred embodiment of the present invention.

Figure 3 is a process chart showing the main process of the manufacturing method of the ultra-thin conductive tape for electromagnetic wave shield according to the present invention.

Fig. 4 is a process chart incorporating an interfacial treatment step in the method for manufacturing an ultra-thin conductive tape for electromagnetic wave shield according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: ultra thin insulation film base layer

20: metal plating layer

30: perforated hole

40: conductive adhesive layer

Claims (12)

An ultra-thin insulating film base layer 10 having a hole 30 perforated at regular intervals and having a physical interface treatment; At least one plating layer 20 surrounded by the perforated hole 30 and surrounding the ultra-thin insulating film base layer 10, wherein the conductive metal is plated by electrolytic, electroless, substitution, vacuum deposition or sputtering; And a conductive adhesive layer 40 attached to an upper plating layer of the ultra-thin insulating film substrate layer or an upper plating layer and a lower plating layer of the ultra-thin insulating film substrate layer. The physical interfacial treatment of the ultra-thin insulating film substrate layer is performed by sequentially washing the ultra-thin insulating film substrate with a gas in a vacuum state and then performing sputter etching and plasma etching, or the ultra-thin insulating film substrate with a gas in a vacuum state. An ultra-thin conductive tape for electromagnetic wave shielding, which is formed by performing corona discharge etching after washing. The method of claim 1, Said ultra-thin insulating film base material is a polyester film, a polyethyleneimide film, or a polyimide film, The ultra-thin film conductive tape for electromagnetic wave shielding characterized by the above-mentioned. The method of claim 1, The conductive adhesive is an acrylic, urethane, vinyl acetate, polyvinyl alcohol, polyvinyl, polyvinylacetate, polyamide or polyethylene-based pressure-sensitive adhesive ultra-thin conductive tape for electromagnetic shielding. The method of claim 1, The size of the holes perforated at regular intervals in the ultra-thin insulating film substrate layer is characterized in that the ultra-thin conductive tape for electromagnetic shielding. The method of claim 1, The at least one plating layer is electromagnetic shielding, characterized in that the electroconductive metal selected from the group consisting of nickel, copper, gold, silver, tin and cobalt is plated by electrolytic, electroless, substitution, vacuum deposition or sputtering method. Ultra Thin Conductive Tape. The method of claim 1, The said ultra-thin insulating film base material layer is 8-20 micrometers in thickness, The ultra-thin conductive tape for electromagnetic wave shielding characterized by the above-mentioned. The method according to any one of claims 1 to 6, The ultra-thin conductive tape for electromagnetic shielding has an electromagnetic shielding rate of more than 70 dB measured according to the ASTM D4935 method, a surface resistance of less than 50 mPa measured according to the ASTM D991 method, and a vertical and vertical (vertical) measured according to the ASTM D991 method. ) Ultra-thin conductive tape for electromagnetic wave shield, characterized in that the resistance is less than 10 mPa.  (a) washing the ultra-thin insulating film substrate selected from the group consisting of a polyester film, polyethyleneimide film and polyimide film with a gas in a vacuum state; (b) physically treating the interface of the ultra-thin insulating film substrate by sequentially performing sputter etching and plasma etching on the cleaned ultra-thin insulating film on the substrate, or performing corona discharge etching on the cleaned ultra-thin insulating film; (c) perforating the physical interfacial treated ultra-thin insulating film substrate at regular intervals; (d) Plating layer on the perforated ultra-thin insulating film substrate by electrolytic, electroless, substitution, vacuum deposition or sputtering electroconductive metal selected from the group consisting of nickel, copper, gold, silver, tin and cobalt Forming a; And (e) forming a conductive adhesive layer by applying a conductive adhesive to a plating layer formed on the ultra thin insulating film substrate or a plating layer formed on the ultra thin insulating film substrate and a plating layer formed on the bottom of the ultra thin insulating film substrate Method of producing an ultra-thin conductive tape for shielding electromagnetic waves comprising a ;. The method of claim 8, In the step (a), the ultra-thin insulating film substrate is placed in a low temperature plasma apparatus, and the cleaning is repeated by injecting 40-200 sccm of argon (Ar) gas while maintaining a vacuum degree of 150-600 mTorr. Method for producing ultra thin conductive tape for use. The method of claim 8, In step (b), sputter etching for 20 to 40 seconds while maintaining the composition ratio of oxygen (O ₂ ) gas: argon (Ar) gas at 30 to 60 sccm: 30 sccm in the low-temperature plasma apparatus, and then 20 to 100 sccm Plasma etching for 30 seconds to 5 minutes using only oxygen (O ₂ ) gas and washing with argon (Ar) gas for producing an ultra-thin conductive tape for electromagnetic shielding. The method of claim 8, The conductive adhesive is an acrylic, urethane, vinyl acetate, polyvinyl alcohol, polyvinyl, polyvinylacetate, polyamide or polyethylene-based pressure-sensitive adhesive manufacturing method for producing an ultra-thin conductive tape for electromagnetic shielding. The method according to any one of claims 8 to 11, Between step (b) and step (c), The physical interface treated ultra-thin insulating film substrate was etched by passing through an etching bath containing a caustic soda solution having a temperature of 80 ° C. and a caustic soda concentration of 10 to 15 wt%, washing with water, and a temperature of 50 to 70 ° C. with hydrochloric acid concentration. Is neutralized under an aqueous hydrochloric acid solution having a weight of 15 to 25 wt%, washed with water, and passed through a palladium catalyst bath composed of a mixed aqueous solution of palladium chloride and tin chloride to adsorb palladium ions to the ultra-thin insulating film substrate, and washed with sulfuric acid. Chemical interface treatment step consisting of removing the tin ions adsorbed together with the palladium ions on the ultra-thin insulation film substrate and forming only the palladium ions by immersing in a sulfuric acid activation tank containing 20 wt% sulfuric acid aqueous solution and washed with water; A method of manufacturing an ultra-thin conductive tape for electromagnetic wave shielding, characterized by the above-mentioned.

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