Waterborne photoresists for use in manufacture of printed circuit boards

A method of forming patterns on a substrate comprising the steps:

• applying waterborne photoimageable composition to a substrate and forming a film, said composition comprising between about 30 wt. % to about 98 wt. % of a waterborne dispersion of an aliphatic urethane acrylate oligomer, and between about 1 wt % to about 25 wt. % photoinitiator;
• allowing the film of the photoimageable substrate to dry;
• applying a mask to the film and irradiating the photopolymerizable film to form an image;
• and
• developing the film to form a pattern;
• wherein the aliphatic urethane acrylate oligomer has the following structure:
• CH2═C(R4)—C(O)—O—A—O—C(O)—NH—R—NH—C(O)—O—R1—O—C(O)—NH—R—
• NH—C(O)—O—CH2—
• C(CH3)(CO2H)—CH2—O—C(O)—NH—R—NH—C(O)—O—R1—O—C(O)—NH—R—NH—C(O)—
• NH—R2—NH—
• C(O)NH—R—NH—C—(O)—O—R1—O—C—(O)—NH—R—NH—C(O)—O—CH2C(CH3
• )(CO2H)—CH2—O—
• C(O)—NH—R—NH—C(O)—O—R1—O—C(O)—NH—R—NH—C(O)O—A—O—C(O)—C(R4)═CH2,
• R33NH+;
• wherein,
• R4 is H or CH3;
• A is —CH2—, —CH2CH2, —CH2(CH2)nCH2, or phenyl;
• R is —CH2—, —CH2CH2—, —CH2—(CH2)n—CH2—, phenyl, isophorone, tetramethyl xylene or dicyclohexyl methane;
• R1 is —(CH2CH2OCH2CH2)m—;
• R2 is —CH2—(CH2)n—CH2;
• R3 is H, methyl, ethyl, n-propyl or n- butyl;
• n is 1 to 10 and m is 1 to 10.