Abstract: According to the present invention, good image resolution of a cationically polymerized epoxy based coating, such as a solder mask or dielectric or etch resist, is provided by combining a cationically polymerized epoxy based coating with conventional epoxy glass substrates cured with a curing agent that does not produce basic reaction products. Preferably, the coating is photoimagable. The method for making the same is also provided. The coating material includes an epoxy resin system comprising between from about 10% to about 90%, preferably about 28% to about 57% by weight of a polyol epoxy resin, and from about 10% to about 90%, preferably about 43% to 72% by weight, of a brominated epoxy resin. Optionally, a polyepoxy resin or an epoxy creosol novolak resin is added to the resin system. The polyepoxy resin may be added from an effective amount up to less than 90% of the resin system; the epoxy creosol novolak may be added from an effective amount up to about 80 pph.

Abstract: The present invention provides a photoimageable soldermask that may be applied using aqueous solvents, thereby reducing the emission of organic solvents. The soldermask contains an epoxy based resin system comprised of at least one epoxy resin, a coating agent, and preferably a cationic photoinitiator and a dye.

Abstract: An improved photoimagable cationically polymerizable epoxy based coating material is provided. The material includes an epoxy resin system consisting essentially of between about 10% and about 80% by weight of a polyol resin which is a condensation product of epichlorohydrin and bisphenol A having a molecular weight of between about 40,000 and 130,000; between about 20% and about 90% by weight of an epoxidized octafunctional bisphenol A formaldehyde novolak resin having a molecular weight of 4,000 to 10,000; and if flame retardancy is required between about 35% and 50% by weight of an epoxidized glycidyl ether of tetrabromo bisphenol A having a softening point of between about 60 C. and about 110 C. and a molecular weight of between about 600 and 2,500. To this resin system is added about 0.

Abstract: An improved photoimagable cationically polymerizable epoxy based coating material is provided, that is suitable for use on a variety of substrates. The material includes an epoxy resin system consisting essentially of between about 10% and about 80% by weight of a polyol resin which preferably is a condensation product of epichlorohydrin and bisphenol A having a molecular weight of between about 40,000 and 130,000; and between about 35% and 72% by weight of an epoxidized glycidyl ether of a brominated bisphenol A having a softening point of between about 60.degree. C. and about 110.degree. C. and a molecular weight of between about 600 and 2,500. A third resin, either an epoxy cresol novolak or a polyepoxy resin, is also added to the resin system. To this resin system is added about 0.