Electroplated nickel gold is much more commonly used on IC substrates (including PBGA), primarily for binding gold wires and copper wires; but when electroplating C substrates, additional conductive wires should be produced in the gold finger binding spot prior to electroplating. However, there is only one layer of copper on https://simonbgikk.bloggadores.com/30652784/6-layer-central-control-pcb-board-for-dummies