Process for manufacturing printed circuits on a metallic substrate

摘要

A printed circuit production process involves subjecting a pure aluminium or aluminium-magnesium alloy substrate to stress relief annealing, pickling, cleaning of at least the surface to be oxidised and anodising in a low electrical conductivity acid solution at 1-5 A/dm<2> current density and at a stabilised temperature to obtain a 10-200 (preferably 90-140) mu m thick oxidised layer. Preferably, the substrate consists of unalloyed aluminium or an aluminium alloy containing 0.12-2.5% magnesium, the impurity contents being less than 0.3% Si, less than 0.05% Fe, less than 0.2% Cu, less than 0.2% Mn, less than 0.1% Cr, less than 0.25% Zn and less than 0.15% others. The anodising bath preferably contains one or more of oxalic, citric, lactic and tartaric acids.