| 摘要 |
<p>A waterborne photoimageable composition, developable in alkaline aqueous solution, which is hardenable to form a hard, permanent layer suitable as a solder mask, comprises A) between 25 and 40 wt.% of a latex acrylic binder polymer having an acid number between 125 and 200 and a number average molecular weight of between 20,000 and 80,000, B) between 13 and 30 wt/% of a waterborne epoxy resin having an epoxy equivalent weight of between 100 and 700, C) between 20 and 25 wt.% of photopolymerizable, multi-functional, alpha , beta -ethylenically unsaturated monomer and/or short-chain oligomer having a molecular weight between 500 and 2000, D) between 4 and 20 wt.% of a free-radical generating chemical system, E) between 0.5 and 10 wt.% of an epoxy curative and/or cure catalyst, and F) between 3 and 12 wt.% surfactant(s), the weight percentages being based on total weight of (A)-(F).</p> |
