| 摘要 |
PURPOSE:To prepare the title substrate excellent in the heat and cold resistance, electrical and mechanical properties, and resistance to abrasion and chemicals and free from warpage by directly casting a specific polyamic acid soln. on a metal foil and then imidizing the solution under a specific heating condition. CONSTITUTION:In preparing a polyamic acid soln. by reacting 0.90-1.00mol of a tetracarboxylic acid dianhydride component with 1.00mol of a diamine component, a polyamic acid soln. (A) obtd, by reacting 3,3',4,4'- biphenyltetracarboxylic dianhydride with p-phenylenediamine and a polyamic acid soln. (B) obtd. by reacting pyromellitic dianhydride with 4,4'- diaminodiphenyl ether are mixed in a ratio of A to B of (55:45)-(75:25), thereby giving a polyamic acid soln. which, when applied, exhibits a dimensional change due to the molecular rearrangement caused by curing of -2 to 20%. The resulting polyamic acid soln. is cast on a metal foil, and the temp. of the soln. is raised from 80 deg.C to 450 deg.C over 0.5hr or longer to imidize the polyamic acid, thus producing a substrate for a flexible printed circuit. |
