A method for liquid crystal alignment using in situ ultraviolet exposure during imidization of polyimide

Homogeneous alignment of liquid crystals can be achieved by a technique using polyimide films and in situ exposure to linearly polarized ultraviolet (LPUV) light during imidization. The alignment layers prepared by this method exhibit higher thermal stability while requiring shorter processing time than the conventional UV alignment method which employs UV exposure after the imidization of polyimide is complete. Multidomain cells can be easily fabricated with the use of a photomask and multistep in situ LPUV exposure during hard bake. (C) 1998 American Institute of Physics. [S0003-6951(98)02949-0].