Electromagnetic Wave Absorbing Structures Including Metal-Coated Fibers And Methods Of Manufacturing The Same

Patent metadata

Field	Value
Publication number	US-2018212333-A1
Application number	US-201615743710-A
Country	US
Kind code	A1
Filing date	Dec 1, 2016
Priority date	Mar 23, 2016
Publication date	Jul 26, 2018
Grant date	—

Abstract

An electromagnetic wave absorber includes a first layer and a second layer disposed on the first layer. The first layer may include a first reinforcing fiber impregnated in a first matrix. The second layer may include a second reinforcing fiber impregnated in a second matrix. The second reinforcing fiber may be plated with a metal magnetic coating layer. The electromagnetic wave absorber may provide electromagnetic wave absorbing ability with a low uncertainty without reducing mechanical properties due to the metal magnetic coating layer.

First claim

What is claimed is:

1 . An electromagnetic wave absorber comprising:
a first layer including a first reinforcing fiber impregnated in a first matrix; and a second layer disposed on the first layer and including a second reinforcing fiber impregnated in a second matrix, the second reinforcing fiber being plated with a metal magnetic coating layer.

2 . The electromagnetic wave absorber of claim 1 , wherein the metal magnetic coating layer includes at least one ferromagnetic material selected from the group consisting of nickel, cobalt and iron.

3 . The electromagnetic wave absorber of claim 2 , wherein the first matrix and the second matrix include a thermo-curable resin.

4 . The electromagnetic wave absorber of claim 1 , wherein the first and second reinforcing fibers include a glass fiber or a Kevlar fiber.

5 . The electromagnetic wave absorber of claim 4 , wherein the first reinforcing fiber includes a metal-uncoated glass fiber or a metal-uncoated Kevlar fiber.

6 . A method of manufacturing an electromagnetic wave absorber, the method comprising:
determining a permittivity or a magnetic permeability according to a target frequency; forming a metal magnetic coating layer on a surface of a reinforcing fiber with an amount or a thickness corresponding the permittivity or the magnetic permeability; and impregnating the reinforcing fiber having the metal magnetic coating layer with a thermo-curable resin.

7 . The method of claim 6 , wherein determining the permittivity or the magnetic permeability according to the target frequency includes generating combination of a real part and an imaginary part of an optimized permittivity according to the target frequency.

8 . The method of claim 7 , wherein generating combination of the real part and the imaginary part of the optimized permittivity according to the target frequency uses Cole-Cole plot satisfying a non-reflection condition in the electromagnetic wave absorber.

9 . The method of claim 6 , wherein forming the metal magnetic coating layer including dipping the reinforcing fiber in a metal salt aqueous solution including a metal salt compound and a reducing agent to perform an electroless plating coating.

10 . The method of claim 9 , wherein the metal salt compound includes a nickel salt compound, and the reducing agent includes a phosphate salt or a boron compound.

11 . The method of claim 10 , wherein the metal magnetic coating layer includes a nickel-phosphorous (Ni—P) alloy or a nickel-boron (Ni—B) alloy.

Assignees

• Korea Advanced Inst Sci & Tech

Inventors

• Kim Chun-Gon
• Nam Young-Woo
• Choi Jae-Hun

Classifications

• H05K9/0088

  comprising a plurality of shielding layers; combining different shielding material structure · CPC title

• B32B38/08

  Impregnating · CPC title

• H01Q17/00 Primary

  Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems · CPC title

• H01Q17/002

  using short elongated elements as dissipative material, e.g. metallic threads or flake-like particles · CPC title

• H05K9/009

  comprising electro-conductive fibres, e.g. metal fibres, carbon fibres, metallised textile fibres, electro-conductive mesh, woven, non-woven mat, fleece, cross-linked · CPC title