液晶離子不純物去除方法最佳化

Abstract

液晶顯示器離子效應的影響是顯示器品質好壞重要的因素之一，離子來源可能從材料方面(PI、液晶、框膠…等)與製程方面(配向、清洗、液晶塗佈…等)。過去有許多文獻探討液晶顯示器中的離子對顯示器的影響與液常發生原因，LCD業界常用來分析離子效應的儀器有﹕電壓保持率（Voltage Holding Ratio，VHR) 與離子密度(Ion density) ，可用來評估分析液晶盒中的離子會造成的電壓變化。如果要分析液晶中的離子種類與含量可用ICP-MS來量測，另外量測液晶電阻率或是弱電流值也可以快速判斷出液晶中離子含量多寡。液晶顯示器中離子會造成如影像殘留Image Sticking (IS) ，顯示不均Mura..等情形。離子有可能來自液晶，所以液晶使用前必須有效的將液晶中離子不純物去除，以降低液晶顯示器不良情況發生。離子不純物可能來自液晶單體合成過程或是在液晶混合配製過程將離子汙染物溶入液晶中。另外LCD廠為降低成本會將產線殘留液晶回收使用， cell製程染或是無塵室空氣中雜質也會溶入液晶中。此研究目的是比較測試何種方法比較有效可以快速去除液晶中離子不純物，找出最佳純化條件，並利用儀器設備分析測試純化後液晶物性、離子含量與光電特性表現。

The ion effect in LCD is one of the key factor to determine LCD quality.Before using liquid crystal in LCD,it is necessary to remove the ion impurity effectively. It would reduce the defect ratio of production.In the past,there are many studies of ion effect in LCD.In the studies of ion effect in LCD,Voltage Holding Ratio (VHR) and ion density are used to demonstrate ion effect in LCD cell.ICP-MS also used to analysis ion in liquid crystal.Another fast method to demonstrated ion quantity in liquid crystal is by using resistivity measurement.Ion impurity of liquid crystal would effect panel perforance,just like image sticking (IS)、flicker or Mura.Ion impurity would be contained in liquid crystal compound.After single component blending,ion of liquid crystal single component and atmosphere moisture would dissolve into liquid crystal mixture.In order to reduce production cost,LCD maker use recycle liquid crystal.This remain liquid crystal is collected from production line.Not only fresh liquid crystal but also recycle liquid crystal have to do purification.This studying is to find the efficient purification method and verify this method by equipment measurement.