Coates Brothers Plc

Wrenford John Thatcher

Nicholas Eric Ivory

Robert J Palmer

Michael Jeffries

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 portions of the layer exposed to the radiation, and removing unexposed 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.

Image-forming process

Coating compositions and their use as solder resists

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.

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Frome, United Kingdom

Wrenford John Thatcher