Effect of the mask geometry on the microstructure forming in through-mask electrochemical micromachining

The manufacturing of surface microstructure is an important means for the modification of surface characteristics of parts. Through-mask electrochemical manufacturing is also an efficient way to fabricate surface microstructures. Nevertheless, in cases where the through-mask electrochemical manufacturing is used for the fabrication of microstructures, many experiments are required to control the cross-section morphology of the microstructures. Furthermore, there is a lack of quantitative analysis of the impact of key variables on the process. In this paper, using numerical simulations based on the mask geometry, we analyze the effects of the aspect ratio of mask feature and the gap between cathode to mask on electrochemical micromachining. We further investigate the influence laws of the mask geometry on the anode current density distribution and forming process. A critical value of "0.8" is also determined for aspect ratio of mask feature which is closely related to the anode current density distribution and forming process. The through-mask electrochemical micromachining experiments confirm the effect laws of the geometric structure of the mask feature. And the critical value (0.8) of aspect ratio can be used as the basis for selecting mask feature.