New results in hydrodynamic radial polishing using HyDRa

Abstract

New results using hydrodynamic radial polishing techniques on assorted materials, using HyDRa are presented. This tool performs corrective lapping and fine polishing by means of a low-cost, foamy abrasive flux. The functioning principle is based on the generation of a grazing, high-velocity, low-pressure, rotational, variable density, abrasive flux with radial geometry. It is currently possible to polish aspheres and free-form optics on diverse materials and sizes. This tool is particularly useful for polishing thin substrates such as membranes and semiconductors since it can be biased for a non-interactive action on the work piece. This process also has the advantage of achieving high removal rates. In order to achieve high degrees of accuracy and repeatability in the HyDRa finishing process, fully automated bias and slurry supply units must be incorporated to the polishing system. The air and slurry supply systems are described, as well as operational tool parameters for optimal polishing performance.