Using proximity exposure to produce asymmetrical lens for light control films

This study aims to produce a high fill factor microlens with a specific tilt angle and uses it to enhancing the brightness of film with a light-emitting component. The lens tilting effect of the high fill factor microlens can alter the light path and collect uniform lateral light or guide light to one side, allowing light-emitting components to be applied in uniform scenarios. TracePro optical simulation software was used to simulate the optimal distance between the mask and the photoresist. Then, photolithography was used to produce high fill factor tilted microlens arrays. The Fresnel diffraction used to select a distance between the photoresist and mask produced a diffraction effect, making each and every lens interact and forming a honeycomb shape. Snell's Law was applied to control the offset angle of the tilted lenses. To obtain a tilted lens effect, the substrate is tilted a certain angle to achieve tilted exposure rather than traditional vertical exposure when performing proximity exposure. Therefore experiments can be carried out using varying distances between the optical masks and photoresists. In addition, asymmetric light control film optical microstructures can be produced without traditional microlens thermal reflow procedures. The high fill factor tilted microlens array is successfully produced. The results of this study have significant potential applications in the reflective display micro-optical components industry.