Method for electrochemical roughening of a substrate

US6423206B1 · kind B1 · utility

Assignee

• Agfa-Gevaert NV · BE

Inventors

• Georg Haby · Liederbach, DE
• Raimund Haas · Frankfurt am Main, DE
• Uwe Gartmann · Eltville am Rhein, DE
• Gunter Hultzsch · Wiesbaden, DE
• Klaus Joerg · Schifferstadt, DE
• Jörg Kaden · Klingelbach, DE
• Hermann Idstein · Oestrich-Winkel, DE

Key dates

• Filing date: Mar 1, 2000
• Grant date: Jul 23, 2002
• Expiry date: Mar 1, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C25F3/04
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

To avoid or minimize the occurrence of cross streaks or current streaks on a substrate that is transported through an electrolytic bath and roughened electrochemically in it, the current density is regulated in the electrolyte between a first alternating or three-phase current electrode and the substrate in such a way that at the beginning of a roughening zone, the current density has a lesser value than within the roughening zone, in the transport direction of the substrate. Downstream of the first alternating or three-phase current electrode, either a further alternating current electrode or a further three-phase current electrode acts on the substrate. In a preferred embodiment, the first alternating or three-phase current electrode has a rounded outline, which is composed of a curved portion and adjoining it a straight portion.