POROUS FILM AND FLEXIBLE PRINT CIRCUIT PLATE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an insulating substrate having good dielectric characteristics and excellent in insulating properties and capable of readily carrying out molding and processing of a flexible print circuit board. SOLUTION: A porous film is composed of a polyamide-imide resin having≥200°C glass transition temperature and≥0.5 dl/g logarithmic viscosity. In the porous film, dielectric loss tangent obtained when measured in 1 GHz frequency is≤0.02 and the film thickness is 5-200μm. The flexible print circuit board is obtained by using the film. COPYRIGHT: (C)2007,JPO&INPIT