POLYIMIDE FILM AND FLEXIBLE PRINTED BOARD USING THE POLYIMIDE FILM

摘要

PROBLEM TO BE SOLVED: To provide a polyimide film having high mechanical characteristics and high adhesion, and further to provide a flexible printed circuit board having high adhesion reliability. SOLUTION: This polyimide film is characterized in that the R value in measured values of tear propagation resistance at arbitrary positions of the polyimide film is <=4 N/cm, and the retention of the tear propagation resistance of the polyimide film after leaving the film at 150 deg.C in 100%RH for 12 hr is >=40%.