A copper pour is a region the CAD tool fills with copper, automatically keeping clearance from traces and pads of other nets and connecting to pads of its own net, often through thermal reliefs. Pours carry ground and power on signal layers, provide shielding and balance copper so the board plates and etches evenly. Unconnected fragments, called islands, are removed or stitched down with vias because they can act as antennas.
Repour the top layer after you move those parts, the copper pour is still showing the old clearances.
Also heard as
- pour
- flood
- fill
- polygon
Related terms
Ground plane
Large continuous copper area, usually a whole layer, that serves as ground and as the reference for signals.
Thermal relief
Spoked connection between a pad and a copper plane that limits heat flow so the joint can be soldered.
Sliver
Very narrow strip of copper or soldermask in the artwork that can peel loose during fabrication.
Thieving
Adding dummy copper patterns to empty areas of a layer so plating and etching come out even across the panel.