Photoimageable permanent resist
AssigneeAMP-AKZO Corporation
InventorsEdward J. Leech, Steven M. Johnson
Life of this patent
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Abstract
Compositions which include an acidified epoxy oligomer, a free radical photoinitiator and a monomer capable of being polymerized by the photoinitiator are used to form aqueous developable, photodefined coatings useful as permanent solder marks for printed circuits and permanent plating resists for additive printed wiring boards. The process for using the compositions include application as a fluid in solvents; drying; exposing to ultraviolet light; developing in an aqueous alkaline solution; and crosslinking the acidified, epoxy oligomers. The articles produced include printed wiring boards with the permanent, photoimaged resist composition thereon.
Claims12
A composition capable of being photoimaged, of being developed in aqueous solutions, and of forming a permanent, photodefined pattern on a surface, the composition comprising:
- a free radical photoinitiator,
- a monomer capable of being polymerized by action of the photoinitiator, said monomer having a viscosity greater than about 1 kPa-s or being a solid at room temperature;
- a resinous compound, selected from solid, resinous compounds having epoxide and acidic functional groups, the epoxide functionality of the resinous compound being greater than 2, and the acid number being greater than about 15 and less than about 60.
Dependencies are inferred from the claim text.