ADHESIVE FILM FOR FLEXIBLE PRINTED WIRING BOARD, LAMINATED FILM FOR FLEXIBLE PRINTED WIRING BOARD USING THE SAME AND FLEXIBLE PRINTED WIRING BOARD USING THE SAME LAMINATED FILM

摘要

PROBLEM TO BE SOLVED: To obtain the subject film useful for various electronic devices, excel lent in bond strength, heat resistance and preservation stability. SOLUTION: This adhesive film for a flexible printed wiring board (FRC for short) is obtained by making a polyolefin-based hot melt (e.g. ethylene-vinyl acetate-maleic anhydride terpolymer) into a film generally having 25-200μm film thickness and irradiating the film with preferablyγ-rays or electron rays in a fixed dose so as to cross-link the film in 10-70% (preferably 30-60%) gel fraction. An electrically insulating film is integrally laminated to one side of the film, optionally a metal foil is integrally laminated to the other side into a FRC. In the lamination, the heating and contact bonding condition is preferably set at 160-180 deg.C under 5-10kg/cm<2> .