Study on die polishing method of microstructured moulds applying low frequency vibration

Abstract

Demands of precision moulds with complicated microstructures for digital devices such as DVD pick-up system, and medical devices such as micro-TAS and solar optics, etc. are increasing. To enhance precision, the structured moulds must be polished after grinding or cutting in order to improve the surface roughness. In this paper, a two-dimensional low frequency vibration (LFV) polishing actuator using PZT is proposed and developed. The LFV consists of four mechanical amplitude magnified actuators, a multilayer stacked piezoelectric actuator (PZT) incorporated with mechanical transformer, and a centre piece. In the polishing experiments, HIPM workpieces were polished with WA slurry by the rotation and revolution type polishing method (RRP). The surface roughness of the work pieces and material removal amount (polished amount) was also evaluated. From the experimental results, it was found that the application of low frequency vibration is useful for realising higher precision in the polishing of microstructured moulds.