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:
May. 17, 1994
Filed:
Feb. 10, 1993
Warren A Alpaugh, Chenango Forks, NY (US);
Anilkumar C Bhatt, Johnson City, NY (US);
Michael J Canestaro, Endicott, NY (US);
Robert J Day, Dryden, NY (US);
Edmond O Fey, Vestal, NY (US);
John E Larrabee, Conklin, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Disclosed is a method of drilling, desmearing, and additively circuitizing a printed circuit board. The printed circuit board is drilled under conditions which produce glass and polymer smeared vias and through holes. The particulate debris is removed by vapor blasting the drilled printed circuit board. Next the printed circuit board is soaked in a solvent to swell the drill smear on the circuit interplanes of the printed circuit board. This solvent is then removed by entrainment in a gas, and a stream of an aqueous, acidic, oxidizing solution is passed through the printed circuit board holes to remove swollen smear in the thru holes and produce an etchback of conductors. After a water rinse an aqueous reducing solution is passed through the printed circuit board to reduce and remove aqueous acidic oxidizing solution, e.g., residual aqueous acid oxidizing solution. The printed circuit board is rinsed to remove the aqueous reducing solution. The surface of the printed circuit board is then seeded, the intended circuitization is photolithographically defined on the printed circuit board, and the circuitization, including the surface circuitization and the plated through hole circuitization, is additively plated.