| abstract |
The invention relates to a method for the preparation of thin polyimide layers by applying a solution of a polyimide prepolymer to a substrate, and subsequently annealing, and has as its object the provision of a method of this type in such a way that the preparation of layers with layer thicknesses of ≦0.2 μm is made possible which layers have a homogeneous character and exhibit good adhesion. For this purpose, the invention provides that film-forming prepolymers of highly heat-resistant polyimides are used which prepolymers give off a high percentage of volatile products in annealing. The method according to the invention is particularly suitable for the production of orientation layers for liquid-crystal displays. |