PHOTO/ELECTRIC POLYIMIDE FILM WIRING BOARD AND METHOD FOR FORMING WIRING METAL FILM ON POLYIMIDE FILM

PROBLEM TO BE SOLVED: To solve the following problem: an exfoliation between a polyimide film and a wiring metal film in an element connection to a polyimide film by an Au-Sn solder bump occurs because the melting point of the Au-Sn is high and a thermal expansion coefficient of the polyimide film is large. SOLUTION: A predetermined wiring metal film 22 is formed after the surface of the polyimide film 18 is roughened by a reverse sputtering or by a reactive ion etching before the wiring metal film 22 is formed by the sputtering or by a vapor deposition on the polyimide film 18 which has a built-in light guide. Further, an organic film covering so as to sandwich the film 22 and the film 18 with only its solder-connection part exposed is provided on the film 22. The organic film is coated by a roll coating or a spin coating. For instance, the polyimide film is used. COPYRIGHT: (C)2005,JPO&NCIPI