An evaluation of currently used printed circuit board materials and processes

A project was undertaken to evaluate currently used printed circuit board materials and processes. The procedure was to use combinations of the different types of commercially available photoresists and etchants to determine their fine line production capabilities. In the evaluation, the line widths were measured and compared with those of the artwork; also, the extent of undercutting was measured. From these data, a minimum line width limit was determined for each photoresist/photoresist thickness/etchant combination.