Composite high shielding thin electromagnetic interference shielding film and preparation method thereof

Abstract

The invention discloses a composite high shielding thin electromagnetic interference shielding film. The film includes a black composite insulation layer, a metal layer and a conductive adhesive layer. The metal layer is located between the black composite insulation layer and the conductive adhesive layer; the black composite insulation layer includes a first insulation layer and a second insulation layer, the second insulation layer is located between the first insulation layer and the metal layer, the glossiness of the first insulation layer is 0-60% (60 DEG), and the hardness of the blackcomposite insulation layer is HB-5H; and the surface of the second insulation layer contacting with the metal layer is a rough surface, and Rz is 0.01-0.5 (excluding 0.5) [mu]m. The film has characteristics of good electrical property, excellent chemical resistance, high shielding performance, excellent bonding strength, less transmission losses, high transmission quality, low water absorption andexcellent reliability; and compared with general electromagnetic shielding films, the film has higher reliability and operationality and can adjust the glossiness values of surfaces, so that the filmcan replace the general shielding film materials.

Description

technical field [0001] The invention relates to the technical field of thinned shielding film for FPC (flexible circuit board) and its preparation, in particular to a composite high-shielding thinned electromagnetic interference shielding film. Background technique [0002] Under the market demand that electronic and communication products tend to be multi-functional and complex, the structure of circuit substrates needs to be lighter, thinner, shorter and smaller; and in terms of functions, powerful and high-speed signal transmission is required. Therefore, the line density is bound to increase, the distance between the carrier board lines is getting closer and closer, and the operating frequency is moving towards high broadband. In addition, if the line layout and wiring are unreasonable, the electromagnetic interference (Electromagnetic Interference, EMI) will become more serious. Therefore, it is necessary to effectively manage Electromagnetic Compatibility (EMC), so as ...

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Problems solved by technology

[0004] The water absorption rate of the EMI shielding film on the market is as high as 1.0-1.5%, which will lead to reliability risks under high temperature and high humidity conditions; and the outer layer of the shielding film is generally difficult to peel off the release film, resulting in poor operability; in addition, the current shielding film The film generally requires a product appearance with a low gloss (low gloss) value in a matte form, and its gloss (gloss) value is generally high

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