HIGHLY STABLE SOLUTION FOR CHEMICAL COPPER PLATING OF PCB HOLES Russian patent published in 2023 - IPC H05K3/42 C23C18/40 

FIELD: technology of forming a conductive layer.

SUBSTANCE: technology of forming a conductive layer on a dielectric surface in the holes of printed circuit boards. Invention can be used for the manufacture of multilayer printed circuit boards in the electronics industry. A highly stable solution of chemical copper plating of printed circuit board holes contains 8-9 g/l of copper sulphate pentahydrate, 2.0-2.2 g/l of nickel sulphate heptahydrate, 30-37 g/l of sodium-potassium tartrate dihydrate, 13-15 g/l of sodium hydroxide, 11-14 ml/l of formalin 37%, 0.00025-0.00035 g/l of sodium diethyldithiocarbamate trihydrate and 0.0005-0.001 ml/l of Berol 556.

EFFECT: invention provides high solution stability (more than 14 days) while maintaining excellent quality of coatings in printed circuit board holes.

1 cl, 1 tbl