| abstract |
Multilayer circuit boards having large area through-hole electrical connections are provided by a process that begins with the fabrication by known means of a drilled and through-hole plated single layer board. Next, a layer of insulating material is applied to either side of the board, leaving at least the through-hole plating exposed. A continuous layer of metal is then deposited on the body, completely covering the insulating layer and through-hole plating. Finally, the deposited metal layer is selectively masked and etched to form conductive circuit patterns on the insulating layer, overlying the original circuit patterns and electrically connected to them by the multiple layer through-hole plating. |