Process for the production of structures

摘要

A process for the production of printed circuit boards and film circuit boards includes providing a starting product with a layer of insulating material between layers of metal. Openings are formed at desired locations through the metal and, at selected ones of those openings, openings are formed through the insulating material by plasma etching or chemical etching. The result of this is back-etching leaving projecting webs of metal extending partly across the openings. The projecting edges are removed by subjecting all of the metal surfaces to etching or electrodeplating which also thins the metal layers. The resulting structure is then plated, adding reinforcing thickness to the thinned metal layers and coating the openings through the insulating material with metal, providing interracial connections between the metal layers. The resulting intermediate can then be formed into a circuit board by forming circuit patterns in the metal layers.