abstract |
A resinous protective coating useful in adhering plastics to metallic substrates. The protective coating is particularly useful as a solder mask and in the manufacture of printed circuit boards with circuit patterns having a resolution of at least 0.25 mm lines and spaces thereon. The protective coating comprises resins dissolved in solvents, wherein the coating, upon being subjected to heat, goes from a liquid or soft "gel-like" state into a solid phase without bleeding. The protective coating is resistant to copper, nickel and gold electroplating baths, adheres to insulating substrates, adhesive coated base materials as well as metallic substrates and is capable of withstanding the thermal shock of dip soldering. |