Manufacturing methods for printed circuit boards

Abstract

A method of forming a plurality of solid conductive bumps for interconnecting two conductive layers of a circuit board with substantially coplanar upper surfaces. The method comprises the steps of applying a continuous homogenous metal layer onto a dielectric substrate, applying a first photoresist and exposing and developing said first photoresist to define a pattern of conductive bumps, etching the metal layer exposed by said development to form said plurality of conductive bumps, removing said first photoresist, applying a second photoresist onto the metal layer, exposing and developing said second photoresist to define a pattern of conductive bumps and circuit lines; etching the metal layer exposed by said development to form a pattern of circuit lines in said metal layer; and removing said second photoresist. The methods of the present invention also provides for fabricating a multilayer circuit board and a metallic border for providing rigidity to a panel.