Printed circuit laminate, printed circuit board produced therefrom, and printed circuit process therefor

摘要

A novel printed circuit laminate product and process are provided for use in connection with a printed circuit board. The laminate is composed of a polyimide support stratum, a copper electrical conductor stratum, and an intermediate adhesive stratum. In one form, the opposite faces of the laminate are separately etched to provide different circuit related features and the laminate as an entirety has through holes, which have particular cross sectional geometry and which are produced by particular process steps. In another form, the copper stratum is laminated to the adhesive face of the adhesive and support strata and is etched after through holes have been drilled in the adhesive and support strata. The geometry is such that the diameter of a through hole in a conducting portion of the conducting stratum is smaller than the diameter of the through hole in the adhesive and support strata, so as to provide a conducting rim or flange for ease and security of mechanical and electrical connection to an associated electrical lead wire or grommet incorporated in a circuit on the object substrate below. The final product of the present invention is a printed circuit structure comprising one or more laminates of the foregoing type, bonded to a rigid printed circuit board.