| abstract |
The present invention provides a substrate that can suppress the occurrence of curling, twisting, warping, and the like due to circuit formation and heat treatment, and that is excellent in heat resistance, flame retardancy, dimensional stability, electrical characteristics, and the like. A conductor layer is provided on at least one outer surface of an insulating layer in which a film made of a fluororesin is laminated on both sides of a film made of a polyimide resin, and the entire thickness of the insulating layer is 25 to 500 μm. And the thickness of the film made of polyimide resin is 0.05 to 1.0 times the total thickness of the film made of fluororesin, and the adhesive strength between the insulating layers is 5.0 N / cm or more. A substrate. [Selection figure] None |