Polishing Characteristics of a Low Frequency Vibration Assisted Polishing Method

Demands of precision molds with complicated microstructures for digital devices such as DVD pick-up system, and medical devices such as μ-TAS and solar optics etc. are increasing. To enhance precision, the structured molds 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 center piece. In the polishing experiments, HIPM workpieces were polished with WA slurry by the rotation & 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 realizing higher precision in the polishing of micro structured molds.