摘要 |
<p>A positive photoresist is electrodeposited onto a substrate, exposed to actinic radiation in a predetermined pattern, and then exposed areas are removed by contact with a developer. When the substrate is a metal-faced laminate, the exposed metal surface may be etched and the residual electrodeposited layer removed by contact with a suitable solvent, optionally after a second, general, exposure to actinic radiation. Suitable electrodepositable positive photoresists include o-nitrocarbinol esters and o-nitrophenyl acetals, their polyesters and end-capped derivatives and quinone diazide sulphonyl esters of phenolic novolaks, having salt-forming groups in the molecule, especially carboxylic acid and amine groups. The process is suitable for the production of printing plates and printed circuits, especially circuits on both sides of a liminate sheet linked conductively through metal-lined holes in the sheet.</p> |