USING DRIE SILICON AS A CUTTING TOOL FOR HIGH PRECISION MICROMACHINING OF METAL ALLOYS

Abstract

This paper reports recent advances in batch-mode micro electro-discharge machining (µEDM) for high precision micromachining of metal alloys such as stainless steels.Highaspect-ratio and high-resolution silicon microstructures formed by deep reactive ion etching (DRIE) are used as cutting electrodes.These replace the previously-reported, LIGA-defined, electroplated copper electrodes, alleviating complexities associated with the LIGA process.A minimum feature size of ≈7 µm is demonstrated on stainless steel 304 in batch-mode µEDM by using DRIE Si electrodes with a width of 5 µm.Features with sizes ≥15 µm have shown excellent repeatability and uniformity across a diescale machining area of 5×5 mm 2 .Machining rates up to ≈5 µm/min.have been demonstrated in micromachining of typical microfluidic structures, including arrays of channels and cavities of different sizes.Other machining characteristics are also discussed.