Fabrication of symmetrical section microfeatures using the electro-discharge machining block electrode method

Abstract

In this paper we report on the development of an electro-discharge machining (EDM) block electrode method for the fabrication of microelectrodes with symmetrical sections, e.g. tapered, circularly stepped, rectangular and triangular. In the EDM process, a newly developed machining strategy is applied for the fabrication of microfeatures. The machining is carried out with multi-pass machining to reduce the volume of material removed, and thus to reduce the possibility of electrode breakage. This is especially of significance when the electrode size is of micrometer scale. This strategy is found to be feasible for producing microelectrodes of various symmetrical sections down to a few tens of micrometers. We demonstrate a few applications of fabricated microelectrodes, including tapered, rectangular and triangular microhole arrays. In addition, we have attempted a case study of the micromachining of a microlens-like array mold and we assess its distribution of accuracy. Thus, this work also contributes to the extension of the micro die-sinking EDM process capabilities by applying different strategies for on-the-machine machining of microelectrodes and microstructures.