Plating deposits metal from solution onto the board. After drilling, a thin electroless copper seed or direct metallisation makes the hole walls conductive, then electrolytic copper builds the barrel and outer conductors up to thickness, typically 20 to 25 micrometres in the hole. In pattern plating only the circuit image is plated and then tinned as an etch resist, while panel plating covers the whole panel. Getting even thickness across a panel and down deep holes is the constant fight.
Plating is thin in the middle of the barrels on the thick boards, slow the line down or pulse plate them.
Also heard as
- copper plating
- electroplating
Related terms
PTH
Plated through-hole: a drilled hole whose walls are copper-plated to connect every layer it passes through.
Aspect ratio
Ratio of a board's thickness to the diameter of a drilled hole, which limits how well the hole can be plated.
Thieving
Adding dummy copper patterns to empty areas of a layer so plating and etching come out even across the panel.
Etching
Chemical removal of unwanted copper from a board, leaving only the protected circuit pattern.