LASER MICROMACHINING APPARATUS WITH INTERCHANGEABLE MASK

摘要

Laser micromachining apparatus for producing a selectable machining pattern on a workpiece, for example a substrate of paper or rubber or for producing a silicon integrated circuit. A high power laser beam carrying a controllable sequence of light pulses passes through a variable attenuator unit and then through a beam expander unit before impinging on a mask containing an enlarged pattern of the mark to be machined. The pattern in the mask consists of a suitable arrangement of small apertures. After diffraction through these apertures and focalisation by a converging optical element, the laser light passes through an optical imaging unit which images the mask onto the workpiece to produce said selectable machining pattern thereon.