US Patent 7947575 Laser machining

A method of laser machining a feature in a substrate includes machining the substrate with a pulsed laser along a scan line so that the successive pulses 81 at the substrate do not overlap but are either contiguous or spaced apart. Pulses 82, 83, 84 in respective succeeding scans of the laser along the scan line, are offset with respect to the starting point of pulses 81, 82, 83 in a previous scan so that multiple successive laser scans provide machining to a required depth while successively smoothing edges, 91, 92, 93, 94 of the feature with each pass.