METHOD FOR DETERMINING QUALITY OF POLYIMIDE FILM, COPPER-CLAD LAMINATE SHEET USING POLYIMIDE FILM AND METHOD FOR MANUFACTURING FLEXIBLE WIRING BOARD

摘要

PROBLEM TO BE SOLVED: To provide a method for determining the quality of a polyimide film for flexible wiring boards for manufacturing a flexible wiring board having a small warp and torsion, a high yield thereby and high productivity.SOLUTION: The method for determining the quality of a polyimide film is used for a flexible wiring board having a metal layer laminated on the polyimide film. The polyimide film has MD and TD directions orthogonal in the flat surface thereof. In the polyimide film, an orientation angle of molecules in a plane showing the maximum orientation being the maximum value obtained by measuring orientation in the flat surface is 0 degree or more and 30 degrees or less in the absolute value of a difference between the TD and MD directions of the polyimide film, and a surface orientation degree ratio of the front to the rear of the polyimide film is less than 1.0.SELECTED DRAWING: Figure 1