NOISE-SUPPRESSION FLEXIBLE FILMS, ELECTROMAGNETIC SHIELDED CIRCUIT BOARDS AND INCLUDING THE SAME

摘要

Provided are a noise reducing soft film which is used to reduce effectively the noise in a range of radio frequency, and a circuit board and a polymer film containing the noise reducing soft film at the surface or the inside. The noise reducing soft film(4) comprises a multilayered hybrid thin film which comprises a Co-Fe-based or Co-Fe/Ni-Fe-based magnetic layer(2) and a polyimide layer. Preferably the multilayered hybrid thin film comprises a polyimide layer; a magnetic layer(2); and a polymer layer(5). The molar ratio of Co/Fe in the Co-Fe-based magnetic layer is 10-90 %; the molar ratio of Ni-Fe-based magnetic layer is 10-90 %; and the polyimide layer is formed by the thermal reaction or photoreaction of a coated poly(amic acid) layer.