The Development Of Touch Solution On Flexible OLED

In recent years,OLED(organic light-emitting diode)display panels become mature in the display field,their wide color gamut,high contrast and other characteristics are better than traditional LCD panels.With its simple structure and thinner thickness,OLED structures based on traditional rigid substrates began to transform to flexible substrates.From flat display to dynamic deformation,then the initial flexible design to current productization,under the condition of ensuring the display quality and life,the product's bending ability and its bending reliability have become a new research direction.In order to improve the bending performance,parts of the flexible OLED film layer need to be optimized and integrated.The touch function layer on the traditional display device were usually made on an additional substrate,then add them on display panel.However,there are different value of compressive stress and tensile stress between different film layers,which will destroy the adhesion between the film layers after many times of bending,and causing function failure,the thicker and the more numbers of the layers there are,the phenomenon becomes more obvious.In the future,how to reduce the thickness of flexible display devices and integrate this part of the function into the display panel has become one of the key technologies in the folding form.Compared with LCD display devices,the existing touch integration technology cannot be directly applied to flexible OLED devices.Flexible OLED's thin-film encapsulation and its low temperature resistance of light-emitting materials cannot be implemented through traditional designs and processes.Now the goal is to integrate the touch function on the OLED device,and the following work has been carried out around the above problems:1.Basing on series of investigations on flexible OLED devices,and establish the process limits in subsequent work for the temperature tolerance of organic light-emitting materials to ensure that the optimized touch process will not adversely affect the optical characteristics of OLED.Then measure the actual temperature in the low temperature process and verify the effect of the low temperature process.Through the analysis of abnormal process,all the processes finally achieved the temperature requirement of less than or equal to 90 ?.2.Starting from the actual structure of the OLED,select the appropriate touch mode and touch layer position.Taking into account the cooperation with OLED devices,the all the processes are optimized to avoid damage to the OLED's encapsulation by touch process.On the other hand,in order to meet the demand for flexibility of future devices,it is necessary to review the materials of the touch trace.Due to the major changes in the overall structure,the electrical performance has also changed.The variables that affect the electrical parameters are analyzed,and the design details are optimized to adapt to the performance of the new touch IC.3.In the actual mass production test,due to the first full low-temperature process,it will still to reveal some problems that have never occurred in the development of unit technology.For several typical problems,continue to improve the process and design until the output of the sample reaches a considerable yield.A common touch evaluation method in the industry will be selected to verify the touch performance of the final sample..After completing the exploration of the flexible touch technology,it provided process experience support for subsequent mass production development.Provides experience for the subsequent development of flexible products,breaking through the limitations of traditional touch technology on flexible displays.