| With the continuous progress of science and technology,the devices are required to develop toward the integration of optic,electrical and mechanical functions.It is difficult to meet the needs of industrial production since the optical elements made by traditional processing methods have large size,heavy weight and high power consumption.In addition,the methods usually are time-comsuming.In recent years,micro-optics components have attracted high attention due to their light weight,small size and simplicity of integration and arraying.Moreover,the microlens array is an important kind of micro-optics components.Many scientific research institutions and universities are studying how to fabricate the microlens arrays while the photoresist hot-melt method is the most widely used since the molding cycle is short and the process is simple.This paper described the microlens array processing in detail.And it also introduced the techniques involved in the process,such as photo-lithography,etching technique and nanoimprint lithography,etc.In the experiments,we designed two masks with different periods and obtained photoresist microlens arrays with various parameters by photoresist hot-melt method.With the control of the processing parameters,we adjusted the microlens dimensions and duty ratio.We fabricated the nickel imprint mold with opposite patterns by electroplating and then removing the photoresist template.Finally,we achieved 4 inches polycarbonate(PC)microlens arrays based on the thermal nanoimprint lithography the by nickel mold.We observed the surface topography of the microlens arrays by SEM measurement.In addition,the phenomenon of the possion bright spot appearing in the photolithography process was analyzed,and we achieved a variety of micro-nano structures by the reasonable use of optical diffraction. |
