Electromagnetic interference suppressor

Patent metadata

Field	Value
Publication number	US-9380736-B2
Application number	US-201214126912-A
Country	US
Kind code	B2
Filing date	Jun 14, 2012
Priority date	Jun 17, 2011
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

According to the present invention, there are provided an electromagnetic interference suppression material capable of exhibiting a good low-pass filter characteristic in an extensive frequency band ranging from a low frequency to a high frequency, and an electromagnetic interference suppression sheet using the electromagnetic interference suppression material. When laminating a conductive layer having a surface electrical resistance of 100 to 5000Ω/□ in which 5 to 25% by volume of a conductive carbon is mixed, and a magnetic layer having a magnetic permeability with an actual number portion of 3 to 45 in which a magnetic material is mixed, to each other, it is possible to obtain an electromagnetic interference suppression sheet suitable for high-density packaging of electronic equipments which is excellent in low-pass filter characteristic in a near electromagnetic field.

First claim

The invention claimed is:

1. An electromagnetic interference suppressor consisting of:
a conductive layer comprising a conductive filler and a resin, and
a magnetic layer comprising soft magnetic particles and a resin,
the conductive layer and the magnetic layer being laminated to each other, in which the conductive layer has a surface electrical resistance of 100 to 5000 Ω/□,
wherein the conductive filler is a conductive carbon, and a content of the conductive filler in the conductive layer is 5 to 25% by volume, and
wherein a transmission loss of the electromagnetic interference suppressor having a thickness of not more than 100 μm in a measurement using a microstripline fitted thereto is not more than 3 dB as measured at 500 MHz and not less than 10 dB as measured at 3 GHz.

2. The electromagnetic interference suppressor according to claim 1 , wherein an actual number portion of a complex magnetic permeability of the magnetic layer as measured at 100 MHz is 3 to 45.

3. The electromagnetic interference suppressor according to claim 1 , wherein the soft magnetic particles are formed of at least one material selected from the group consisting of carbonyl iron, magnetite, spinel ferrite and Sendust.

4. The electromagnetic interference suppressor according to claim 1 , wherein the conductive layer having a thickness of 20 to 100 μm and the magnetic layer having a thickness of 50 to 200 μm are laminated to each other.

Assignees

• Yamamoto Kazumi
• Toda Kogyo Corp

Inventors

• Yamamoto Kazumi

Classifications

• Y10T428/32

  Composite [nonstructural laminate] of inorganic material having metal-compound-containing layer and having defined magnetic layer · CPC title

• H05K9/0088 Primary

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

• Y10T428/24967

  Absolute thicknesses specified · CPC title

• Y10T428/31938

  Polymer of monoethylenically unsaturated hydrocarbon · CPC title

• Y10T428/31678

  Of metal · CPC title