Electromagnetic wave absorber and electronic device

Patent metadata

Field	Value
Publication number	US-10631446-B2
Application number	US-201815939558-A
Country	US
Kind code	B2
Filing date	Mar 29, 2018
Priority date	Apr 7, 2017
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

An electromagnetic wave absorber includes: a first layer having a first enclosing layer that encloses an electromagnetic wave radiator, and a first metal film formed on the first enclosing layer.

First claim

What is claimed is:

1. An electromagnetic wave absorber comprising:
a first layer having a first enclosing layer that encloses an electromagnetic wave radiator from all directions, and a first metal film formed over the first enclosing layer,
wherein the first metal film has one of a shape having a surface roughness, an uneven shape having a concave portion and a convex portion, and a gentle sloping shape, and
a slit is formed as an opening in the first metal film.

2. The electromagnetic wave absorber according to claim 1 , wherein the first layer includes a second enclosing layer formed over an opposite surface of the first metal film other than a surface of the first metal film where the first enclosing layer is formed.

3. The electromagnetic wave absorber according to claim 1 , further comprising: an electronic circuit mounted over the first metal film.

4. The electromagnetic wave absorber according to claim 1 , wherein the first metal film is electrically coupled to the electromagnetic wave radiator.

5. The electromagnetic wave absorber according to claim 1 , wherein the first metal film has a coiled pattern that is wound around the electromagnetic wave radiator.

6. The electromagnetic wave absorber according to claim 1 , wherein the first enclosing layer contains resin.

7. The electromagnetic wave absorber according to claim 1 , wherein the first enclosing layer contains a carbon material.

8. The electromagnetic wave absorber according to claim 1 , wherein a thickness of the first enclosing layer is (2m−1)/4 times (m is a natural number) a wavelength of electromagnetic waves propagating inside the first enclosing layer.

9. The electromagnetic wave absorber according to claim 1 , further comprising: a second layer having a third enclosing layer that encloses the first layer, and a second metal film formed on the third enclosing layer.

10. The electromagnetic wave absorber according to claim 1 , wherein one or more resistance elements is provided over the slit.

11. An electronic device comprising:
an electromagnetic wave radiator configured to radiate electromagnetic waves; and
an electromagnetic wave absorber configured to enclose the electromagnetic wave radiator;
wherein the electromagnetic wave absorber includes a first layer having a first enclosing layer that encloses the electromagnetic wave radiator from all directions, and a first metal film formed over a surface of the first enclosing layer,
the first metal film has one of a shape having a surface roughness, an uneven shape having a concave portion and a convex portion, and a gentle sloping shape, and
a slit is formed as an opening in the first metal film.

12. The electronic device according to claim 11 , wherein the first metal film has a lower resistivity than a resistivity of ferrite.

13. The electronic device according to claim 11 , wherein the first metal film has a lower resistivity than a resistivity of ferrite.

14. The electronic device according to claim 11 , wherein one or more resistance elements is provided over the slit.

Assignees

• Fujitsu Ltd

Inventors

• Hirose Tatsuya

Classifications

• H05K9/0086

  comprising a single discontinuous metallic layer on an electrically insulating supporting structure, e.g. metal grid, perforated metal foil, film, aggregated flakes, sintering · CPC title

• H05K9/0088

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

• H05K9/0024 Primary

  Shield cases mounted on a PCB, e.g. cans or caps or conformal shields · CPC title

• H05K9/0081

  Electromagnetic shielding materials, e.g. EMI, RFI shielding (H05K9/0003 takes precedence) · CPC title

• H05K9/0084 Primary

  comprising a single continuous metallic layer on an electrically insulating supporting structure, e.g. metal foil, film, plating coating, electro-deposition, vapour-deposition · CPC title