Drilling with Lasers has come a long way since Theodore Maiman reported the first working laser some forty Years ago. New laser sources and specially developed processes are entering the market to move the mere drilling to the next level of micro drilling. Surgical needles in the medical field, turbine blades for the aviation industry, and gas filters for the automotive industry are just some examples that come to mind here. Nevertheless, the market asks for higher throughput, smaller diameter, higher aspect ratios, and all of the above within a minimum of tolerances. Commonly used laser pulses within the microsecond-regime show a significant thermal side effect which is unacceptable if used e.g. in combustion nozzles. Reducing the thermal load by shortening the pulse length into the nanosecond-regime could be a compromise to bridge the gap between quality and production speed in high precision drilling.
The scope of this work is to show the influences of the process parameters in micro drilling applications. Utilizing a nanosecond pulsed Nd:YAG at its fundamental wavelength of 1064 nm, hole sizes of less then 10μm and up to 200μm diameter will be demonstrated. A variation of drilling principles are studied and the advantages as much as the disadvantages are discussed.