A process used during manufacture of printed circuit boards comprises protecting metal pads andor through-holes to provide a tarnish-resistant and solderable coating. The shield plate has a first portion extending along the side surface and closing the opening, a second portion extending along the top surface, and a bent portion positioned between the first portion and the second portion and bent at a second angle being smaller than the first angle. One or more electrodes are coupled to a power supply, and a controller controls a clamping voltage supplied to the one or more electrodes via the power supply. An embedded programmable processor manages route insertion and deletion in the prefix tables, together with configuration of the virtual memory banks.