Patent ID: 9469735
Filing Date: 2016-10-18
CPC Classification: B32B,C08J

Claim Text:
1. A method of manufacturing a polyimide film having impregnated glass fabric, comprising: (1) impregnating glass fabric with a polyamic acid solution, thus obtaining a polyamic acid film having impregnated glass fabric; (2) flattening the polyamic acid film having impregnated glass fabric obtained in (1) (first flattening process) at a temperature between the Tg of the polyamic acid film and the imidization temperature of the polyamic acid; (3) subjecting the polyamic acid film obtained in (2) to imidization, thus obtaining a polyimide film having impregnated glass fabric; and (4) flattening the polyimide film having impregnated glass fabric obtained in (3) (second flattening process) at a temperature between the Tg of the polyimide film and the thermal decomposition temperature of the polyimide film; wherein the flattening steps are performed by applying pressure using cylindrical rollers or flat plates having a surface roughness of 0.5 to 2 nm.