| abstract |
An improved method of preparing polyamide acid for processing of semiconductors from a diamine and a tetracarboxylic acid dianhydride with a diaminocarbonamide, is provided (1) by reacting the components at below 40 DEG C. until the reduced viscosity reaches above 0.5 dl/g. at 30 DEG C., and then, (2) by adjusting the reduced viscosity to more than 0.3 dl/g, at 30 DEG 0 C. and the solution viscosity to 500-3,000 cps at 25 DEG C. by heating at 50 DEG -100 DEG C. By applying the polyamide acid obtained by the method to semiconductor apparatus, they get sufficient heat-resistance without pin holes, and their reliability may be greatly improved. |