| abstract |
A process for manufacturing printed circuits provided with through holes, which comprises a cleaning pretreatment including a possible treatment by an organic solvent, a treatment in an alcaline solution of permanganate and a treatment for permanganate reduction, and a subsequent metallization treatment including a treatment for conditioning the walls of the through holes, a treatment for mordanting the copper surfaces, a precatalysis treatment, a catalysis treatment and a metallization treatment by a chemical copper both, wherein three treatments, namely reducing the permanganate, conditioning the walls of the through holes and mordanting the copper surfaces, are performed in a single step. The treatment for conditioning the walls of the through holes is performed by means of non-surfactant, water soluble polymers belonging to the group of the cationic polyelectrolytes. The composition for carrying out three treatments in a single step comprises an acid, hydrogen peroxide, a stabilizer for the hydrogen peroxide and a non-surfactant conditioner belonging to the group of the cationic polyelectrolytes. |