摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a flexible printed circuit board, capable of suppressing degradation in adhesion strength caused by diffusion of copper under thermal load during long period, having excellent heat resistance against the thermal load during long period, as well as excellent heat resistance and excellent solder heat resistance against thermal load during a short period at high temperature, without heating at high temperature after formation of an electroless nickel plating layer, without need for performing formation of the electroless nickel plating layer with a plurality of times of steps.SOLUTION: After forming an electroless nickel plating layer by a single plating on both surfaces of a polyimide film having been subjected to thermal treatment at 530°C or higher of maximum heating temperature for imide-formation or a polyimide film having been subjected to thermal treatment at 490°C or higher, the double sided nickel plating laminate polyimide film having been heated for 2.5 hours or longer at a range of 100 to 180°C is used to manufacture a flexible printed circuit board by wiring processing. |