PROCESS FOR FILING MICRO-BLIND VIAS

摘要

The invention provides a process for filling µ-blind vias in the manufacture of printed circuit boards, which process comprises the following steps: (i) providing a bath electrolyte for galvanic plating with metallic coatings comprising a copper metal salt and optionally organic additives, (ii) operating the bath with direct current density of 0.5 to 10 A/dm<2>, or current pulses at an effective current density of 0.5 to A/dm<2>, (iii) withdrawing part of the electrolyte from the galvanic bath, (iv) adding an oxidizing agent to the part of the electrolyte which has been withdrawn, (v) optionally irradiating the withdrawn electrolyte with UV light and (vi) recycling the withdrawn part to the galvanic bath and replacing the organic additives destroyed by the oxidation treatment.