针对大F数(大于10)微透镜阵列难以制备的现状, 提出了一种制备大F数微透镜阵列的方法.首先采用传统光刻胶热熔法及刻蚀技术制作出成形的微透镜阵列, 再将一层具有较高粘滞系数的光刻胶均匀地涂覆在该微透镜阵列上, 在光刻胶的粘滞作用以及烘烤过程中光刻胶自身表面张力的共同作用下, 微透镜阵列的F数得到提高.采用该方法制备的二氧化硅微透镜阵列的F数达40, 与传统大F数微透镜阵列的加工方法相比, 该方法简便易行、制备的微透镜阵列面形良好, 且只需调节光刻胶的粘滞系数, 即可获得F数不同的微透镜阵列.

In the view of the present problem that the microlens array of high F-number (more than 10) is difficult to be manufactured, this paper proposed a new fabrication method for it. Firstly, A photoresist layer with high viscosity was spin-coated evenly on a microlens array fabricated by melting photoresist and etching technology. Under the viscosity of photoresist and the surface tension of photoresist in curing process, the F-number of microlens array increased observably. Compared with the traditional processing method, this fabrication method is very simple and the surface profile of microlens array is very good. In addition, microlens arrays with different F-number could be obtained with the viscosity of photoresist was adjusted. Based on the method, a microlens array with F-number up to 40 was fabricated. The experimental results show that the profile of the microlens array is good enough to verify the feasibility of the fabrication method.