You can create a copper area that covers the entire surface of the board.
To create a copper area
Do the following:
-
Choose the command PCB » Copper » Filling » Copper Plane or click the
button in the toolbar.
The Spacing from copper to board outline property included in the PCB tab of the project properties allows you to specify the distance to be kept between the outline of the copper planes and the edge of the board.
This function can be used to create split copper planes. To create full copper planes, activate the Full Plane option in the layer properties.