Patent ID: 8866043

Claim:
An improved system for forming through holes in a workpiece with at least one laser pulse, said system including a controller, a laser and optics, said through hole having a taper, a surface finish and an exit diameter, said workpiece including substantially homogeneous metallic material and having a top surface and an ablation threshold, and said laser pulse having a spot size, pulse duration and peak power, the improvement comprising: a controller operatively connected to said laser and said optics to produce at least one laser pulse with said peak power about 20% greater than said ablation threshold of the workpiece, said spot size having a 1/e 2 diameter at said top surface of said workpiece greater than about two times the exit diameter of said through hole and said pulse duration greater than about 10 nanoseconds and direct it to said workpiece thereby producing said through hole with said taper, said surface finish and said exit diameter.