Abstract: A process for the formation of a patterned resist of a photocurable material on a circuit board, the uncured portion of which is water soluble. The process includes the steps of forming a layer of an aqueous emulsion of a photocurable material upon the circuit board, drying the layer to a substantially dry and non-tacky state, imagewise exposing the layer to radiation to cure (harden) portions of the layer exposed to the radiation, and removing unexposed (uncured) portions of the layer by washing with water. In a preferred embodiment, the photocurable material is an organic solvent solution of an epoxy acrylate derived from an epoxy novolac resin which has been carboxylated to render it alkali-developable.

Abstract: A process for the formation of a patterned resist image upon a substrate comprises the steps of: (i) mechanically applying a layer of a suspension of a powdered solid photocurable material in a liquid carrier to the substrate; (ii) drying the resultant layer by evaporation of the liquid carrier and reflowing the powder, under the action of heat, to give a coherent film; (iii) imagewise exposing the dried film to radiation through a patterned mask whereby portions of the film exposed to radiation are cured; and (iv) subsequently developing the exposed film by removing unexposed portions thereof with an appropriate solvent.