| 摘要 |
PURPOSE:To obtain a flexible wiring board which is superior in adhesion with a metallic thin film and flex resistance and has a few curl, by a method wherein a solution of an aromatic polyimide to be obtained through diamine composed of symmetric aromatic primary diamine and siloxane diamine having no substituting group or its precursor is applied to the metallic thin film and heated. CONSTITUTION:Aromatic polyimide or its precursor is obtained through reaction between aromatic tetracarboxylic acid or its acid anhydride and a diamine compound. 3,3',4,4'-biphenyl tetracarboxylic acid and its acid anhydride are preferable as the aromatic tetracarboxylic acid. P-phenylene diamine, 1,1,3,3- tetramethyl-1,3-bis(4-aminophenyl)disiloxane are illustrated as the above diamine. A flexible wiring board 3 where a polyimide layer 1 is formed on a metallic thin film 2 is obtained by a method wherein a solution of an organic solvent of the obtained aromatic polyimide or its precursor is applied onto the metallic thin film such as a copper foil and heated. |
