Fine surface finishing method for 3-dimensional micro structures

We developed a new finishing method using an advanced ECM (electrochemical machining) assisted by fine abrasive grains in order to finish surfaces of 3-dimensional micro components used in MEMS. With the method, a fine surface of selected micro-area, which is not obtained by micro-EDM (electrodischarge machining) nor conventional ECM, is created in a few minutes. We also developed an advanced machine which has a performance to make 3-D complicated micro structures with fine surfaces by the combination of the micro-EDM and the developed finishing method. The performance is achieved by a sequential process without workpiece handling from the micro-EDM to the finishing. Using the new machine, we obtained a high precision shaft with a mirror-like surface. The result is satisfactory to apply the method to make a cylindrical substrate for a rotor of micro wobble motor. We are sure that the process will be applied to producing practical micro mechanical components.