Tatsuta Electric Wire & Cable Co., Ltd.

Takahiko Katsuki

Hiroshi Tajima

Yuusuke Haruna

Sirou Yamauchi

Kenji Kamino

Sougo Ishioka

Tsuyoshi Hasegawa

An electromagnetic wave shielding film with high bending resistance and high electromagnetic wave-shielding characteristics, even when used with high-frequency signal transmission, is disclosed. The electromagnetic wave shielding film includes an adhesive layer; a shielding layer placed on the adhesive layer; and an insulating layer placed on the shielding layer, wherein a plurality of openings having an opening area of 1 to 5000 μmare formed in the shielding layer, the openings include first openings having opening areas of more than 1 μmand 300 μmor less and second openings having opening areas of more than 300 μmand 5000 μmor less, and the percentage of the number (cumulative frequency) of the first openings among the openings is 30 to 90%, and the percentage of the number (cumulative frequency) of the second openings among the openings is 10 to 70%.

Electromagnetic wave shielding film

An electromagnetic wave shielding film has permeability to volatile components, shielding characteristics, and resistance to folding. The electromagnetic wave shielding film includes an adhesive layer; a metal layer made of a metal and placed on the adhesive layer; and an insulating layer placed on the metal layer. Multiple openings are formed in the metal layer; the openings include openings (A) including island-shaped metal layer fragments, each opening (A) having island-shaped metal layer fragments formed therein, and the openings (A) including island-shaped metal layer fragments include openings (A) including one or more island-shaped metal layer fragments. Each opening (A) defines an opening (A) including island-shaped metal layer fragments in which a total area of the island-shaped metal layer fragments accounts for 40 to 80% of an area inside a contour of the opening (A).

Electromagnetic wave shielding film and shielded printed wiring board

A shielded printed wiring board with electromagnetic wave shielding film on both sides thereof is produced by placing electromagnetic wave shielding films on the two sides of the printed wiring board, with ends thereof protruding past an end of the printed wiring board. The protruding ends of the electromagnetic wave shielding films are brought together, with an air gap therebetween, and an initial application of heat and pressure causes the ends of the electromagnetic wave shielding film to adhere to each other, but without completely curing adhesive resin components of the electromagnetic wave shielding films. Protective film layers are removed from the electromagnetic wave shielding films, followed by subsequent application of heat and pressure to complete cure of the adhesive resin and to remove the air gap.

Method for manufacturing shielded printed wiring board and shielded printed wiring board

Provided is an electromagnetic wave shielding film capable of easily exhibiting excellent conductivity between a ground member and a shielding layer when the ground member is disposed on the electromagnetic wave shielding film. In the electromagnetic wave shielding film, the conductive adhesive layer, the shielding layer, and the insulating layerare laminated in this order, and a ratio [conductive adhesive layer/insulating layer] of Martens hardness of the conductive adhesive layerin accordance with ISO14577-1 to Martens hardness of the insulating layerin accordance with ISO14577-1 is 0.3 or more.

The present invention aims to provide a ground member that can be mounted on any position, wherein misalignment is less likely to occur between conductive filler particles of the ground member and a shielding layer of a shielding film when a shielded printed wiring board including the ground member is repeatedly heated and cooled to mount components thereon. The ground member of the present invention includes: a conductive external connection member having a first main surface and a second main surface opposite to the first main surface; conductive filler particles disposed adjacent to the first main surface; and an adhesive resin for fixing the conductive filler particles to the first main surface, wherein each conductive filler particle includes a low-melting-point metal.

Growing community of inventors

Kizugawa, Japan

Takahiko Katsuki