Using proximity exposure to produce asymmetrical lens for light control films

Abstract

This study aims to produce a high fill factor micro lens with a specific tilt angle (asymmetric lens) and use it to enhancing the brightness of film with a light-emitting component. The asymmetric lens effect of the high fill factor micro lens can alter the light path and collect uniform lateral light as well as guide light to one side, allowing light-emitting components to be applied in uniform scenarios. Trace Pro optical simulation software was used to simulate the optimal gap between the mask and the photoresist. Then, photolithography was used to produce high fill factor asymmetric lens array. Snell's Law was applied to control the offset angle of the asymmetric lens array. To obtain an asymmetric lens effect, the substrate was tilted a certain angle to achieve tilted exposure rather than traditional vertical exposure when performing proximity exposure. Therefore experiments can be carried out using different gaps between the optical masks and the photoresist. In addition, the asymmetric light control film optical microstructures can be produced without conventional thermal reflow procedures. The high fill factor asymmetrical micro lens array is successfully produced. The results of this study have significant potential applications in the reflective display micro-optical components industry.