METHOD FOR FORMING PRINTED CIRCUITS WITH SELECTIVELY ETCHABLE METAL LAYERS, AS WELL AS METHOD FOR FINAL FORMING PATTERN OF HIGH DEFINITION

The present invention provides a method for producing high density electronic circuit boards comprising the steps of depositing a layer of a first metal upon a layer of foil to produce a composite then attaching the composite to an insulative support to produce a laminate. The layer of foil is then removed from the layer of first metal. Photoresist is then applied to the layer of first metal, exposed and developed. During the development of the photoresist portions of the photoresist are removed from the layer of first metal. A layer of third metal is then plated upon the portions of the layer of first metal that are not covered by the photoresist. All remaining photoresist and the portions of the layer of first metal which are not covered by the third metal are then removed producing a finished fine-line pattern having conductive and insulative areas. The finished fine-line pattern may then be utilized to produce a circuit board.