Ronald A Reed

US Patent:

49649485, Oct 23, 1990

Filed:

Nov 13, 1989

Appl. No.:

7/435703

Inventors:

Ronald G. Reed - Monument CO

Assignee:

ProtoCAD, Inc. - Colorado SPrings CO

International Classification:

B44C 122
C23F 102
C03C 1500
C03C 2506

US Classification:

1566591

Abstract:

A process of forming plated through-holes in a printed circuit board involves placing a film of fluid ink having electrically conductive properties on a side wall of the hole, curing the film to a solid and electroplating a layer of metal on the conductive ink film. The conductive ink preferably is a composition including conductive particles such as carbon and silver flakes. The ink also preferably includes a thermosetting or radiation curable binder and a thinner. The film of ink is cured before the layer of metal is electroplated thereon. The plated through-hole is protected from the etchant when the conductors are etched by placing a radiation curable putty material into the hole, curing it, and then depositing a layer of resist on top of the cured putty and a conductive sheet clad to the substrate of the circuit board.