METHODS FOR DRILLING FEATURES IN A SUBSTRATE USING LASER PERFORATION AND LASER ABLATION

In one embodiment, a method of drilling a feature in a substrate includes directing a pulsed laser beam focal line into the substrate at a plurality of locations, the laser beam focal line generating an induced absorption within the substrate such that the laser beam focal line produces a perforation extending through a thickness of the substrate at the plurality of locations to form a perforation contour. The method further includes directing a focused ablation laser beam into the substrate and ablating at least a portion of the substrate along an ablation track that is offset from the perforation contour by a perforation-ablation offset ΔnP-Ablation to remove substrate material within a shape defined by the perforation contour to form the feature. The perforation-ablation offset ΔnP-Ablation is such that the feature has a chipping with chips having a size of less than 50 μm.