Thieving, or copper balancing, fills open areas of a layer with small isolated copper dots, squares or hatching that connect to nothing. Isolated traces in sparse areas otherwise draw extra plating current and end up thicker than dense areas, and etch rate also varies with copper density. Fabricators add thieving to panel borders on their own but ask before adding it inside the board outline, because it can affect impedance and RF performance.
Fab wants to add thieving in the empty corner of layer 4, fine, but keep it 2 mm away from the RF traces.
Also heard as
- copper thieving
- copper balancing
Related terms
Plating
Electrochemical deposition of copper or other metals on a board, building hole walls and surface conductors.
Copper pour
Area of copper flooded in by the CAD tool around traces and pads, usually tied to ground or a power net.
Etching
Chemical removal of unwanted copper from a board, leaving only the protected circuit pattern.