| 摘要 |
PROBLEM TO BE SOLVED: To prepare a polyimide film having improved punching properties with suppressed generation of punching burrs and punching scraps in a punching process, and to provide a stiffener for a flexible circuit board obtained by using the polyimide film. SOLUTION: The polyimide film has a thickness of at least 120μm, and an R value represented by the formula 1: R(%)=(d/F)×100, of at most 35%, wherein d (N/mm) is a fluctuation range of tear strength and F (N/mm) is the average tear strength. COPYRIGHT: (C)2004,JPO |
