Process for metallization of a nonconductor surface, especially on a circuit board having preexisting copper surfaces

US5183552A · kind A · utility

Assignee

• SCHERING CORPORATION · US

Inventors

• Burkhard Bressel · Berlin, DE
• Heinrich Meyer · Berlin, DE
• Walter Meyer · Bonndorf, DE
• Klaus Gedrat · Berlin, DE

Key dates

• Filing date: Feb 14, 1991
• Grant date: Feb 2, 1993
• Expiry date: Feb 14, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S205/92
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The process for directly metallizing a circuit board having nonconductor surfaces, includes reacting the nonconductor surface with an alkaline permanganate solution to form manganese dioxide chemically adsorbed on the nonconductor surface; forming an aqueous solution of a weak acid having an acid dissociation constant, for loss of a proton in aqueous solution, between 0.1 and 0.01, and of pyrrole or a pyrrole derivative and soluble oligomers thereof; contacting the aqueous solution containing the pyrrole monomer and its oligomers with the nonconductor surface having the manganese dioxide adsorbed chemically thereon to deposit an adherent, electrically conducting, insoluble polymer product on the nonconductor surface; and directly electrodepositing metal on the nonconductor surface having the insoluble adherent polymer product formed thereon. The oligomers are advantageously formed in aqueous solution containing 0.1 to 200 g/l of the pyrrole monomer at a temperature between room temperature and the freezing point of the solution.