A new finishing method using an advanced ECM assisted by fine abrasive grains was developed, in order to smooth and finish surfaces of 3-dimensional micro components used in micromachines. With the method, a fine surface of selected micro-area, which is not obtained by micro-EDM nor conventional ECM, was obtained in a few minutes. We also developed an advanced machine which has a performance of making 3-D complicated micro structures with fine surfaces by the combination of micro-EDM and the developed finishing method. The performance is achieved by a sequential process from the micro-EDM to the finishing without handling workpiece. Using the new machine, we obtained a high precision shaft with a mirror-like surface. The result is satisfactory to apply the method to making a cylindrical substrate for a rotor of a micro wobble motor. The machining process combined the micro-EDM and the new finishing will be applied to producing micro components such as mechanical parts, mirrors and molding dies.

The objective of this study is to realize a manipulator of 0.5 mm in outside diameter as a part of 'research and development of micro machine technology.' This manipulator is intended as a part of a working robot to fix or observe the inside wall of a small pipe. One of the important problems of this research is to establish a processing method of a tubular small structure. MIM, metal injection molding, has been adopted to fabricate such a small structure. As a processing method to machine small molds for MIM, finish processing with surface roughness of Rmax 0.1 µm has been under our research applying 'vibrational processing technology,' which was developed on our own. This paper presents the results of 'vibrational processing technology' surface finishing of molds for metal injection.