Optical selective demetallization apparatus

Abstract

An apparatus for applying optical energy to selectively remove material carried upon a substrate, preferably in substantially parallel lanes of material-free areas, which apparatus comprises an optical generator for generating optical energy in a primary beam, partitioning devices for dividing the primary beam into a plurality of derivative beams, reflective devices for reflecting each of the derivative beams to form a plurality of working beams which impact the substrate, focusing lenses for focusing each of the plurality of working beams upon the substrate, and transport means for transporting the substrate in a direction transverse of the plurality of working beams to effect continuous removal of material in substantially parallel lanes from the substrate by the working beams. In the preferred embodiment of the apparatus, phase retarders are utilized to shift the vector orientation of selected of the derivative beams in a manner whereby each of the working beams is of substantially equal intensity, a beam expander is used for diffusing the primary beam to reduce energy concentration upon optical elements of the apparatus. The lens assemblies are configured to focus the working beams upon the substrate in a substantially elliptical pattern, the major axis of which pattern is substantially aligned with the direction of transport of the substrate, and evacuating assemblies are associated with each working beam to evacuate removed material to preclude deposition of removed material upon the lens assemblies as well as to preclude impairment of focusing of the working beams upon the substrate.