VIA-HOLE DRILLING IN A PRINTED CIRCUIT BOARD USING A CARBON MONOXIDE LASER

摘要

Apparatus (10) for drilling a via-hole in a printed circuit board (PCB) (74) includes a carbon monoxide laser (12) deliver laser radiation pulses. The pulses have a relatively broad wavelength-range, and slow rising and falling edges. The rising and falling edges of the pulses are clipped using and acousto-optic modulator (52). A dispersion- compensator (64) compensates for dispersion in the clipped pulses introduced by the AOM (52). Achromatic focusing optics (70) focus the dispersion-compensated, clipped pulses on the PCB (74) for the via- hole drilling.