Electromagnetic wave shield film, printed wiring board using same, and rolled copper foil

Abstract

An electromagnetic wave shield film in which peeling off between a metal thin film and an adhesive layer is prevented and a printed wiring board employing the electromagnetic wave shield are provided. An electromagnetic wave shield film is formed by laminating at least a metal thin film and an adhesive layer in order, and the water vapor permeability of the electromagnetic wave shield film according to JISK7129 is 0.5 g/m 2 per 24 hours or higher at a temperature of 80 degrees centigrade, a moisture of 95% RH, and a pressure difference of 1 atm.

1 . An electromagnetic wave shield film comprising at least a metal thin film and an adhesive layer, the metal thin film and the adhesive later being laminated in order, wherein, water vapor permeability according to JISK7129 is 0.5 g/m 2  per 24 hours or higher at a temperature of 80 degrees centigrade, a moisture of 95% RH, and a differential pressure of 1 atm. 
     
     
         2 . The electromagnetic wave shield film according to  claim 1 , wherein,
 the metal thin film is formed by impregnating, into a solvent, a metal sheet which is formed of a hard-to-melt component with low solubility in the solvent and an easily-melted component more soluble in the solvent than the hard-to-melt component,   the easily-melted component is particles of a granular material dispersed in the metal sheet, and   
       as the granular material is dissolved in the solvent, openings are formed in the metal thin film. 
     
     
         3 . The electromagnetic wave shield film according to  claim 2 , wherein, the hard-to-melt component is metal mainly made of copper, whereas the easily-melted component is copper oxide. 
     
     
         4 . The electromagnetic wave shield film according to  claim 2 , wherein, the hard-to-melt component is metal mainly made of copper, whereas the easily-melted component is copper oxide (I). 
     
     
         5 . The electromagnetic wave shield film according to  claim 2 , wherein, each of the openings is in a range of 0.1 to 100 μm in diameter. 
     
     
         6 . The electromagnetic wave shield film according to  claim 2 , wherein, the number of the openings per 1 cm 2  in the metal thin film is 10 to 1000/cm 2 . 
     
     
         7 . The electromagnetic wave shield film according to  claim 2 , wherein, the metal thin film is in a range of 0.5 to 12 μm in thickness. 
     
     
         8 . The electromagnetic wave shield film according to  claim 1 , wherein, the metal thin film is a rolled copper foil. 
     
     
         9 . A rolled copper foil in which openings are formed by wet etching, wherein, each of the openings is in a range of 0.1 to 100 μm in diameter, the number of the openings per 1 cm 2  in the rolled copper foil is in a range of 10 to 1000/cm 2 , and the rolled copper foil is in a range of 0.5 to 12 μm in thickness. 
     
     
         10 . A shield printed wiring board comprising the electromagnetic wave shield film according to  claim 1 .