Modohar PIA(amber)/PAB(supper foggy black) polyimide film are rigid, high performance substrate film and they are kind of heat resistant films possessing excellent physical, chemical, and electrical properties. As the polymer structure having a high rigidity and strong intermolecular forces, thus has superior chemical, physical, electrical and radiation-resistant properties, especially those having a lower coefficient of thermal expansion, and high rigidity and excellent dimensional stability. They can be applied to various harsh working environment.