Patent ID: 8354009

Claim:
A method of manufacturing a flexible circuit board, the method comprising the steps of: (a) forming a cross-linking layer on a surface of a substrate by making high-energy Argon gas ions and sputtered metal ions hit against and penetrate into the surface of the substrate with a magnetron sputtering apparatus; (b) forming a thin metal film by the metal ions which hit against and penetrate into the cross-linking layer formed in step (a), and sputtered neutral metal particles; and (c) forming a thick metal film on the thin metal film formed in step (b) while controlling stress through magnetron sputtering; wherein the cross-linking layer is formed according to a cross-linking phenomenon occurring due to ultraviolet light in the vacuum, the light being produced simultaneously when the high-energy Argon gas ions hit against and penetrate into the surface of the substrate in the magnetron sputtering apparatus, the cross-linking layer improving adhesiveness between the substrate and the thin metal film; wherein in step (b), the thin metal film is formed by nucleation wherein metal ions which hit against and penetrate into the cross-linking layer formed in step (a), and single magnetron sputtering employing DC power and dual magnetron sputtering employing two-pole pulse DC power are performed to deposit thin films forming the thick metal film while controlling the stress of the thin films, the two-pole pulse DC power including a negative pulse and a positive pulse.