In this work, we present the use of an ultrafast laser system for the high aspect ratio micro-drilling of aluminum alloy thin foils. Hole sizes in between 20 and 40 lm were fabricated in arrays with sub-micron level precision in terms of diameter and hole location. The Design of Experiment approach was employed to analyze the influences of the laser process parameters like laser power, frequency, and exposure time on the resulting quality of the produced micro-holes. The outputs measured were hole size, location and the variability in these measures. The metallurgical and geometrical features were examined using a scanning electron microscope and optical microscope. Processing throughput is also important in industrial laser processes. The parametric effect on circularity and taper has been observed to understand the features of the hole. The features of holes help in fabrication in a plethora of industries to produce applications such as fins, filters, microgrid circuits, and biomedical devices.