Electrochemical etching of ultrafine tungsten wire poles

Abstract

Electrochemical micromachining has good application potential for processing of materials. The size of microtool poles is the key in electrochemical micromachining, which directly affects the size and accuracy of processed elements. To minimise the size of tool poles, we proposed a micromachining technique in which a tungsten wire was etched in two steps and the diameter of 1 μm was achieved successfully. The effect of solution concentration on the current–voltage relationship during processing of tungsten wire was investigated, and the proper solution concentration was determined. The effect of voltage applied between two electrodes on the quality of tungsten wire pole was examined, and the applied voltage was optimised. Moreover, the changes of tungsten wire diameter with time and current were studied, and thus a microtungsten wire pole with a given diameter can be produced easily.

Keywords:

• Electrochemical etching
• Ultrafine tungsten wire pole
• Etching in two steps
• Current density
• Effects of the applied voltage