A major operation in printed circuit board manufacturing is the plating process. After the etching and application of a mask to the panel has been applied (see imaging process) the panel is now ready to have the copper plating applied to the circuit pattern on the board.
Plating is the best method for applying the thin layer of copper to the printed circuit board panel because of the intricate and detailed pattern of the circuitry. Plating provides the most effective and efficient way to apply the conductive material to the circuit board panel.
The plating process starts by clamping the PCB panels in plating racks and immersing them in a series of chemical baths that clean the copper pattern (circuitry). The PCB panels are then immersed in copper plating solutions. The solution and panels are electrolytically charged opposite polarities, which trigger copper ions to migrate to the uncoated copper areas on the panel. Copper is plated to a thickness of 0.0015 on the surface and in the holes.
The PCB panels are moved from plating bath to plating bath either by hand or by machine. Automatic plating equipment is computer controlled, and the hoist (or hoists) moves the racked panels through the bath sequence without manual intervention.
The circuitry pattern, now covered with extra copper, is further electroplated with tin or tin/lead (solder). The tin or tin/lead plating sequence is similar to the copper plating process. Afterward, the panels are removed from the plating racks. The tin or tin / lead covering the pattern will protect the circuitry in subsequent processing steps.
