超薄可撓曲液晶顯示器之研究

Abstract

本研究中我們使用一般液晶顯示器的架構，以一般液晶顯示器所需要的上、下軟性材質的偏光板(Polarizer) 當作液晶顯示器的基板，以達到可撓曲及厚度超薄的特性。因為偏光板本身不耐高溫，在製作過程中容易因溫度造成偏光板的捲曲，所以傳統液晶顯示器需要高溫製程的氧化銦錫(Indium Tin Oxide, ITO)導電層及聚醯亞胺(Polyimide, PI)配向製程，就無法應用在以偏光板做為基板的液晶顯示器上，故針對材料及製程的選用上我們就必需優先考慮溫度對偏光板的影響。 本論文使用多面體矽氧烷奈米粒子(Polyhedral Oligomeric Silsesquioxanes, POSS)摻雜在液晶，因POSS吸附在基板上，將可誘導原本不具有配向膜的液晶盒產生垂直配向能力，因此避開聚醯亞胺配向層的高溫製程；此外，我們亦用導電高分子(poly(3,4-ethylenedioxythiophene)：poly(styrenesulfonate), PEDOT：PSS)混合奈米碳管塗佈於偏光板上當作導電層，用以取代濺鍍ITO的製程。為避免軟性顯示器撓曲造成顯示器間隙(cell gap)不均或者發生上下基板短路而影響光電特性，本研究以高分子單體混入液晶，再加以曝光相分離方式來形成高分子牆(Polymer wall)，用以支撐上下基板並維持液晶盒的間隙及光電特性。

ABSTRACT The polarizers have been applied as the substrates for fabricating an ulta slim and bendable liquid crystal displays (LCDs) in this work. The polarizer can only stand for ~ 70 ℃ manufacture temperature. Therefore, the high temperature processes for the conventional LCDs, such as sputtering indium tin oxide (ITO) and baking polyimide (PI) alignment layers, are not suitable for plastic LCDs. In this research, the polarizer is coated with the mixture of poly-3,4-ethylenedioxythiophene：poly-styrenesulfonate (PEDOT：PSS) and carbon nanotube (CNT) to replace ITO as the conducting layer. The addition of polyhedral oligomeric silsesquioxanes (POSS) nanoparticle into the LC layer is used to align LC vertically, and the polymer walls fabricated by photo-induced phase separation are also applied for maintaining the cell gap under bending conditions in this work.