Papers by Author: Dong Yea Sheu

Abstract: This study describes a novel process to drill small holes in brittle materials such as glass, silicon and ceramic using a self-elastic polycrystalline diamond (PCD) drilling tool. In order to improve the surface roughness and reduce crack of the small holes, a new type of self-elastic PCD drilling tool equipped with vibration absorbing materials inside the housing was developed to fabricate small holes in glass in this study. The self-elastic PCD drilling tools could absorb the mechanical force by the vibration absorbing materials while the PCD tool penetrates into the small holes. Compared to conventional PCD drilling tools, the experimental results show that high-quality small holes drilled in glass can be achieved with cracking as small as 0.02mm on the outlet surface using the self-elastic PCD drilling tool.

Abstract: This work used micro dispensing technology to fabricate the master of microlens array, then uses electroforming technology to replication the Ni mold insert of microlens array and finally used micro hot embossing to replicate the plastic microlens array. This work used the Si10 resin by AutoStrade Company for dispensing material. The resin material was exposed to 80W halogen light. The resin will be hardened and become convex by surface tension effect on exposition. It can be used as the master of microlens array. This work sputtered a silver layer of 150 nm thick on the master for conducting electricity layer. The electroforming technology replicateed on the Ni mold insert from the master of microlens array. Finally, the micro hot embossing technology was used to replicate the molded microlens array. The molding experiment used PMMA and PC optical film. The experiment studied the influence of processing parameters of hot embossing by processing temperature, embossing pressure, embossing time and de-molding temperature. This work used the Taguchi’s Method to search the best processing parameter for molded microlens array. This work used the microscope, surface profiler and SEM to measure the surface profile of master, mold insert and molded microlens array. This work also used AFM to measure the surface roughness of master, mold insert and molded microlens array. In addition, this work measured the optical strength and the focal length to discuss optical characteristics of molded microlens array.