Abstract: The present disclosure relates, according to some embodiments, to a method of fabricating a flexible metal-clad laminate comprising forming a metal layer on a surface of a polyimide film, wherein the metal layer and the polyimide film are contacting each other and forming a laminate, and heating the laminate at a temperature of about 80° C. to about 140° C. until a weight loss of the laminate reaches about 1% or higher.

Abstract: An object of the present invention is to provide a flexible circuit board that maintains high insulation reliability, exhibits high wiring adhesion, has low thermal expansion, and allows the formation of a fine circuit thereon. Specifically, the present invention provides a flexible circuit board, wherein at least a nickel plating layer is laminated on a polyimide film to form a polyimide film provided with a nickel plating layer and a wiring pattern is applied to the nickel plating layer thereof. The polyimide film has a thermal expansion coefficient of 0 to 8 ppm/° C. in the temperature range from 100 to 200° C., and the nickel plating layer has a thickness of 0.03 to 0.3 ?m.

Abstract: An object of the present invention is to provide a flexible circuit board that maintains high insulation reliability, exhibits high wiring adhesion, has low thermal expansion, and allows the formation of a fine circuit thereon. Specifically, the present invention provides a flexible circuit board, wherein at least a nickel plating layer is laminated on a polyimide film to form a polyimide film provided with a nickel plating layer and a wiring pattern is applied to the nickel plating layer thereof. The polyimide film has a thermal expansion coefficient of 0 to 8 ppm/° C. in the temperature range from 100 to 200° C., and the nickel plating layer has a thickness of 0.03 to 0.3 ?m.