摘要 |
<p>A polyimide film obtained by using as starting materials a symmetric aromatic m-substituted primary diamine and a symmetric aromatic P-substituted primary diamine in a given proportion. This film has excellent heat resistance, electric properties, and flexibility. In providing this film on a substrate, a precursor of the polyimide, i.e. a polyamic acid, is applied to the substrate without using any adhesives, and a reaction is allowed to proceed to form a polyimide to thereby provide the polyimide film on the substrate with good adhesiveness. The resulting flexible printed circuit board has the above-described excellent properties.</p> |