Electromagnetic wave absorbing and shielding film, method of manufacturing the same, and cable including the same

• US 20090075068A1
• Filed: 12/06/2007
• Published: 03/19/2009
• Est. Priority Date: 09/13/2007
• Status: Abandoned Application

• Current Assignee: Empko Co., Ltd.
• Original Assignee: Empko Co., Ltd.
• Inventors: Lee, Jong Young, Pyo, Jung Seok
• Application Number:
  US11/987,990
• Publication Number:
  US 20090075068A1
• Time in Patent Office: Days
• US Class Current: 428/336
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 15/20 comprising aluminium or copper B32B15/016 and B32B15/017 take precedence
• CPC Class Codes: B32B 2037/243 Coating
• CPC Class Codes: B32B 2038/0092 Metallizing
• CPC Class Codes: B32B 2307/202 Conductive
• CPC Class Codes: B32B 2309/105 Thickness
• CPC Class Codes: B32B 2457/00 Electrical equipment
• CPC Class Codes: B32B 27/281 comprising polyimides
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 27/365 comprising polycarbonates
• CPC Class Codes: B32B 37/203 One or more of the layers being plastic
• CPC Class Codes: H05K 9/0098 for shielding electrical cables
• CPC Class Codes: Y10T 428/263 Coating layer not in excess of 5 mils thick or equivalent
• CPC Class Codes: Y10T 428/264 Up to 3 mils
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

Disclosed herein are an electromagnetic wave absorbing and shielding film, a method of manufacturing the same, and a cable including the electromagnetic wave absorbing and shielding film. The electromagnetic wave absorbing and shielding film includes an electromagnetic wave absorbing layer, in which a plate-like metal flake is formed using a metal powder in the form of a paste or ink, and an electromagnetic wave shielding layer attached to the electromagnetic wave absorbing layer, thus absorbing and shielding electromagnetic wave and reducing noise.

For this, the present invention provides a method of manufacturing an electromagnetic absorbing and shielding film, in which the method includes forming a plate-like metal flake using a spherical metal alloy by an attrition mill, which operates at a predetermined speed for a predetermined time, with the addition of steel use stainless (SUS) balls or ceramic balls and surfactants, and washing the plate-like metal flake with ethyl alcohol, methyl alcohol or water and drying the washed metal flake, the method including: mixing the metal flake powder with resin in a ratio of 30 to 95 wt %:70 to 5 wt % using a mixer and stirring the same to form a metal paste; and coating the metal paste on an electromagnetic wave shielding layer, and a communication cable including the thus formed electromagnetic wave absorbing and shielding film.

Claims

1. A method of manufacturing an electromagnetic absorbing and shielding film, in which the method comprises forming a plate-like metal flake using a spherical metal alloy by an attrition mill, which operates at a predetermined speed for a predetermined time, with the addition of steel use stainless (SUS) balls or ceramic balls and surfactants, and washing the plate-like metal flake with ethyl alcohol, methyl alcohol or water and drying the washed metal flake, the method comprising:

dispersing powder capable of absorbing electromagnetic wave selected from the group consisting of Fe—

Si alloy, Fe—

Si—

Cr alloy, amorphous substance, sendust (SDST) alloy, High-Flux powder, molypermalloy powder (MPP), pure iron alloy (Fe—

Si, or Fe—

Si—

Cr), amorphous alloy (Fe—

Si—

Al—

Cr), carbon coated iron, Ni—

Zn ferrite powder, Mn—

Zn ferrite powder, and a mixture thereof, into a binder solution, thus forming electromagnetic wave absorbing paint; and

coating the electromagnetic wave absorbing paint on the surface of a film capable of shielding electromagnetic wave and drying the resulting film, thus forming an electromagnetic wave absorbing and shielding film, of which one side is an electromagnetic wave absorbing layer having a thickness in a range of 10 to 100 μ

m and the other side is an electromagnetic wave shielding layer.

2. The method of claim 1, wherein the electromagnetic wave shielding layer is formed by one of the steps of:

1) laminating a metal thin film as an electrical conductive layer selected from the group consisting of aluminum foil, copper foil, silver foil, and nickel foil on a polymer film selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polyaramide, polycarbonate, polyamide, polyimide, polyamideimide, and aramid;

2) depositing a metal component as an electrical conductive layer selected from the group consisting of Al, Cu, Ag, and Ni on the polymer film; and

3) dispersing a metal component as an electrical conductive layer selected from the group consisting of Al, Cu, Ag and Ni into a binder solution and coating the resulting solution on the polymer film,

wherein the electrical conductive layer has a thickness in a range of 5 to 20 μ

m, the polymer film has a thickness in a range of 12 to 50 μ

m, and the total thickness of the electromagnetic wave shielding layer is in a range of 17 to 70 μ

m.

3. An electromagnetic wave absorbing and shielding film manufactured by the method of claims 1 and 2.

4. A communication cable in which a communication line, a power line, and an earth wire are wrapped with an insulating coating, the communication cable comprising the electromagnetic wave absorbing and shielding film manufactured by the method of claims 1 and 2, wherein the electromagnetic wave absorbing and shielding film installed inside the insulating coating wraps the communication line, the power line and the earth wire, of which the electromagnetic wave shielding layer is arranged toward the communication line, the power line and the earth wire and the electromagnetic wave absorbing layer is arranged toward the insulating coating.

5. The communication cable of claim 4, wherein a drain wire having excellent electrical conductivity is arranged inside the electromagnetic wave shielding layer together with the communication line, the power line and the earth wire, and the electromagnetic wave shielding layer is grounded to the earth wire by the drain wire.