Electrophoretically depositable photosensitive polymer composition

Claim 1

An aqueously developable, negative acting, electrophoretically depositable photoresist consisting essentially of an aqueous solution or emulsion of at least one polymer, free of ethylenic unsaturation, having less than about 200 milliequivalents of carrier groups per 100 grams of said polymer or polymers, said carrier groups being selected from the group consisting of amines or carboxylic acids, an effective amount of an acid or base for the neutralization of said amine or carboxylic acid carrier groups, respectively, to charged carrier groups such that said polymer or polymers contain from at least 10 milliequivalents to about 50 milliequivalents of charged carrier groups per 100 grams of said polymer or polymers, a photoinitiator, and an unsaturated crosslinking monomer, and where said photoresist can be anaphoretically or cataphoretically deposited, depending on the charge of said carrier groups on said polymer, as an adherent uniform film on a conductive surface, and where after exposure of selected portions of said film to actinic radiation, said unexposed portions of said photoresist film are capable of being removed by development with an aqueous solution of a weak organic acid, in the case of a cataphoretically deposited photoresist, or an aqueous base solution, in the case of an anaphoretically deposited photoresist, and where the exposed portions of said photoresist film remain resistant to oxidizing agents used to etch said conductive surface, and where said exposed photoresist film portions can be stripped from said surface using an aqueous solution.