Avoiding Contamination in Laser Ablation of Polymers
Original Publication Date: 1988-Dec-01
Included in the Prior Art Database: 2005-Feb-16
Excimer laser ablation of polymer material produces debris which is electrically charged. Normally, such debris collects on the surface of the material being treated, and the debris must be cleaned off using a plasma etch technique. As an alternative, a mask can be used to prevent the excimer laser light from reaching the substrate except in the regions where via holes are to be etched through polyimide to the underlying metal. The mask must be removed to clean the part; then it must be put back and re-aligned so that solder can be evaporated through the hole in the mask to fill the via hole with metal. These process steps could be avoided if there were no debris from the laser etching deposited on the part.