聚醯亞胺薄膜表面特性對液晶預傾角影響之研究

Abstract

在液晶顯示器中，因液晶之預傾角會影響到顯示器之光電特性，故需對其做管控，但在現行管控方法中，並無法有效對預傾角異常品做攔檢。本論文中研究不同商用聚醯亞胺配向膜並搭配不同配向深度參數做出實驗所需之樣品，希望透過不同成膜特性與材料特性的配向膜來探討其表面特性與液晶預傾角間之關係。

實驗結果發現在五款配向膜中當配向深度逐漸增加時，液晶之預傾角度皆會隨之下降，但其變化幅度會因材料特性而有所不同，在配向膜表面接觸角量測結果中也發現不同的材料特性，也會影響到配向製程後的表面極性變化。

因此，本論文研究配向膜表面特性與預傾角間的關係，並探討如何將實驗結果應用於面板生產製程中，並找出每款配向膜的表面特性與預傾角間的關係，來提前評估配向製程後之預傾角度，減少異常品的產出，達到降低成本的目標。

Polyimide (PI) has been widely applied in the LC displays (LCDs) industry as the alignment layers to align LC molecules in a certain orientation and conformation with a specific pretilt angle. The pretilt angle is very important and required for LC devices to obtain a defect-free alignment and also to improve their electro-optical performance. In current manufacture process, the pretilt angle is determined after the LC panel is assembled.

Therefore, the LC panel with non-qualified pretilt angle can not be detected in advance to reduce the cost. The purpose of this work is to study the relationship between LC pretilt angle and the surface properties of PI in order to determine the pretilt angle just after the process of mechanically buffed PI.

The results showed that the pretilt angle decreased with the rubbing depth, and the relationship strongly depended on the PI materials. By measuring the surface energy of the buffed PIs, it was observed that some PI materials showed the dependence between the pretilt angle and the polarity.