The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 04, 1985
Filed:
Jun. 01, 1984
Dieter K Bahrle, Schonaich, DE;
Friedrich W Schwerdt, Herrenberg, DE;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method of making printed circuits, where on both sides sacrificial foils are laminated onto a synthetic resin prepreg. Through-holes are drilled. The copper foil is subsequently etched off. A negative photoresist foil is laminated on the prepreg surface roughened by etched-off copper dendrites. The foil is exposed and developed in accordance with the respective conductive pattern. Subsequently, copper is sputtered onto the surface of the photoresist, the surface and the bottom of the photoresist channels defining the conductors, and onto the surface of the drilled holes by means of magnetron-enhanced cathode sputtering. The copper sputtered onto the surface of the photoresist is removed by means of a scrubbing roller. Then, copper is deposited in accordance with the additive process on the copper sputtered in the photoresist channels and the drilled holes. After the stripping of the photoresist, the printed circuit is completed.