Supply
Specifies the settings for Thermal symbols.
The value for Thermal isolation determines the distance between a polygon and the annular ring of the pad or via that is joined to the polygon through a Thermal symbol.
The Generate thermals for vias flag permits thermal connections for vias. Otherwise vias are fully connected to the copper plane. This applies also for polygons. But you can disable this option for individual polygons with CHANGE THERMALS OFF and a click onto the polygon's contour.
Inside hatched polygons Electronics doesn't generate Thermal symbols for vias that do not have a direct contact to one of the polygon lines.
Pads or SMDs marked with the flag NOTHERMALS (CHANGE THERMALS OFF) in the Package Editor will be connected without Thermal symbols.