High quality micro machining with tailored short and ultra short laser pulses

In the production of micro-scaled products and products with micro and nano scaled surface functionalities, laser ablation becomes a more and more important tool which is able to generate structure sizes in the range of 10 - 100 m and with new machining strategies even in range smaller than one micrometer. One crucial task for all laser machining applications is the realisation of a high surface quality with a minimum of roughness and with no thermal effect on the geometry of the part. Using ultra short pulsed lasers with pulse durations of 10 ps in pulse bursts of several pulses with a time spacing of 20 ns each and adapted pulse energies, the surface quality of metal micro ablation have been increased significantly. Compared to single pulse ablation, the roughness has been decreased by a factor of 2 and at the same time the ablation efficiency has been increased up to a factor of 4. This technology has been adapted to the production of micro moulding tools as well as for the manufacturing of functional surfaces with improved wetting capabilities and for other micro parts such as micron sized filters and embossing tools.