Electromagnetic shielding material

Patent metadata

Field	Value
Publication number	US-2018263145-A1
Application number	US-201815917420-A
Country	US
Kind code	A1
Filing date	Mar 9, 2018
Priority date	Mar 13, 2017
Publication date	Sep 13, 2018
Grant date	—

Abstract

Provided is an electromagnetic wave shielding material including a multilayer structure in which at least one metal foil and at least two resin layers are closely laminated, wherein both surfaces of each metal foil are closely laminated to the resin layers; wherein each metal foil satisfies the following relationship with each of the two resin layers adjacent to the metal foil: 0.02≤V M /V M ≤1.2, in which: V M is a volume fraction of the metal foil relative to a total volume of the metal foil and the resin layer; V M′ is (σ R −σ R′ )/(σ M +σ R −σ R′ ); σ M is a true stress (MPa) of the metal foil at breakage when a tensile stress is applied to the metal foil; σ R is a true stress (MPa) of the resin layer at breakage when a tensile stress is applied to the resin layer; and σ R′ is a true stress (MPa) of the resin layer when a logarithmic strain same as a logarithmic strain at breakage of the metal foil is applied to the resin layer.

First claim

1 . An electromagnetic wave shielding material comprising a multilayer structure in which at least one metal foil and at least two resin layers are closely laminated,
wherein both surfaces of each metal foil are closely laminated to the resin layers; wherein each metal foil satisfies the following relationship with each of the two resin layers adjacent to the metal foil:
0.02 ≤V M /V M′ ≤1.2, in which

V M is a volume fraction of the metal foil relative to a total volume of the metal foil and the resin layer;
V M′ is (σ R −σ R′ )/(σ M +σ R −σ R′ );

σ M is a true stress (MPa) of the metal foil at breakage when a tensile stress is applied to the metal foil; σ R is a true stress (MPa) of the resin layer at breakage when a tensile stress is applied to the resin layer; and σ R′ is a true stress (MPa) of the resin layer when a logarithmic strain same as a logarithmic strain at breakage of the metal foil is applied to the resin layer.

2 . The electromagnetic wave shielding material according to claim 1 , wherein each metal foil satisfies the following relationship with each of the two resin layers adjacent to the metal foil:
0.2 ≤V M /V M′ ≤0.6.

3 . The electromagnetic wave shielding material according to claim 1 , wherein each metal foil forming the electromagnetic wave shielding material has a thickness of 4 μm to 100 μm.

4 . The electromagnetic wave shielding material according to claim 1 , wherein each resin layer forming the electromagnetic wave shielding material has a thickness of 4 μm to 250 μm.

5 . The electromagnetic wave shielding material according to claim 1 , wherein the metal foil and the resin layers forming the electromagnetic wave shielding material are closely laminated by thermocompression bonding without interposing an adhesive layer.

6 . The electromagnetic wave shielding material according to claim 1 , wherein a total thickness of the at least one metal foil is 100 μm or less, and a total thickness of the resin layers is 500 μm or less.

7 . A method for producing an electromagnetic wave shielding molded article comprising molding the electromagnetic wave shielding material according to claim 1 .

8 . The method for producing the electromagnetic wave shielding molded article according to claim 7 , wherein the molding is carried out by pressure forming.

Assignees

• Jx Nippon Mining & Metals Corp

Inventors

• Tanaka Koichiro

Classifications

• 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

• C25D3/12

  of nickel or cobalt · CPC title

• C25D3/08

  Deposition of black chromium {, e.g. hexavalent chromium, CrVI} · CPC title

• H05K9/0088 Primary

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

• B29K2105/256

  Sheets, plates, blanks or films · CPC title