The Effects of Pulse Period on Nanosecond Laser Microfabrication

摘要

Laser micromachining/structuring is a promising technique to create micropatterns on material surfaces with very low distortion to peripheral area and high precession. Thin sheets of stainless steel, aluminium and silicon were micromachined with ultraviolet (UV) laser pulses around 30 ns to create micron-scale features. The laser pulses with different pulse periodicities ranging from 5 to 40155 with same pulse energy, fluence and number of pulses/unit area has been applied to study the impact on the microfeatures with respect to the pulse periods. The microchannels fabricated with different pulse periodicities on stainless steel, Al and Si with a nanosecond laser exhibited significant variations in terms of depth and cleanliness of the surface. Stainless steel and Al showed an enhancement of 30% in the depth of the microchannels compared to high pulse period and Si has recorded an increase of 100%. The experimental results show that the pulse period per time interval between successive pulses is significant in determining the geometry and surface cleanliness of the laser machined microchannels.