Electro-chemical micro drilling using ultra short pulses

Electro-chemical machining (ECM) has been rarely applied in micro machining because the electric field is not localized. In this work, ultra short pulses with tens of nanosecond duration are used to localize dissolution area. The effects of voltage, pulse duration, and pulse frequency on the localization distance were studied. High quality micro hole with 8 μm diameter was drilled on 304 stainless steel foil with 20 μm thickness. Localization distance can be manipulated by controlling the voltage and pulse duration, and various hole shapes were produced including stepped holes and taper free holes.