Research On Polymer Liquid Crystal Display Technology Driven By Organic TFT

With the development of information era and computer multimedia technology,people have more and more demand for large screen display devices.Whether it is the emergence of folding screen mobile phones or the appearance of nearly 100 inch display screen,it shows that the research on large screen devices has become a hot spot.For the super-size display screen,it has the advantages of rich color,high resolution,strong visual impact,far visible distance,etc.As a result,it can produce better economic and social benefits,and is widely used in square,conference room,large buildings and other places.But the mainstream LED small spacing and LCD splicing technology have many problems,such as the need for main source,high power consumption,large increase of maintenance and production cost,limited using scenarios,etc.Therefore,the development of the super large screen display technology has reached a bottleneck.In this paper,the polymer dispersion liquid crystal display technology with low backlight demand and no polarizer and the technology of organic TFT with low technology difficulty and low preparation cost are combined together.A polymer dispersion liquid crystal display technology driven by organic TFT is formed.Based on the driving conditions of polymer dispersed liquid crystal display,the related technological conditions and parameters of organic TFT module are explored,in order to expect the future successful combination of the two.The main research contents are as follows:1.Firstly,the design of the bottom layer processing pattern of the device structure,mainly including the screen printing pattern of the substrate ITO and the processing drawing of the mask.The main design basis of screen printing pattern is the custom pixel size and gate source electrode width,and it is difficult to change pattern after processing.Mask theoretically includes two kinds of mask,insulation layer and metal layer.In this paper,we realize the reuse of two mask plates by many experiments.The repeated production cost of mask can be greatly reduced With the increase of etching complexity and degree of freedom.2.This paper carries out the function simulation under COMSOL tool,mainly for the channel length,insulation thickness and organic layer thickness,which are three important process parameters to carry on the function simulation,in order to studies its influence on the TFT electrical characteristics.The process can provide certain guidance for the subsequent process parameter adjustment.3.The final production process and material selection of ITO pattern,silicon nitride insulation layer,copper metal layer and active layer are analyzed and improved in detail.The optimum RF power of magnetron sputtering silicon nitride is 140 W,the best power of laser etching copper metal layer is 30 W,organic ink drop negative pressure is-1.5kpa and positive pressure of 20 KPa.The results show that cleaning process of glass substrate greatly affects the success rate.Under the condition of this process,the organic TFT drive module with saturated current up to a few microamperes and still working normally at 50 V is finally prepared.The conclusion that it can drive polymer dispersed liquid crystal display is obtained,and the feasibility of new metal layer processing pattern is proposed and confirmed.