液晶光配向膜之研究

Abstract

本研究探討曝光於波長為325nm下的光配向膜CBDA-BAPP的特性。從實驗中可知：(1)液晶分子會排列於垂直電場的方向，且曝光時間越長，排列效果越好。 照光時間超過一定量時，排列的效果則不再有顯著差異。(2)可利用光罩與重複曝光的技術製造圖像於液晶樣本上。(3)從AFM的表面影像中可知因光繞射產生的溝槽並不能使液晶分子排列，而PI分子的非等向性的分佈才是主要原因。(4)UV光偏振方向與基板平行所製造的液晶盒其平均預傾角是零度；若偏振方向與基板不平行則平均預傾角不為零。

The photo-modified polyimide films for aligning liquid crystal, CBDA-BAPP, exposed to linearly polarized light (λ=325nm) has been investigated. From experiments, we conclude : (1)The alignment direction of the LC is perpendicular to the polarization direction of LPUV light. The degree of uniformity of LC alignment increased with increasing exposure time on PI films ; the degree of uniformity is stablized when exposure time exceeded some value. (2)Using mask and double exposure technics , we can make patterned LC cells. (3)From AFM topography study , we suggest that the anisotropic dispersion force is the main factor rather than the macro-groove effect to align LC molecules. (4)The pretilt angle caused by normal LPUV light on PI films is zero. The pretilt angle generated by oblique LPUV light is not zero.