User Guide

which the polygon is drawn (see page 116). You can also specify whether
or not vias are to be connected through thermals. The minimum clear
-
ances from elements carrying other signals specified in the Design Rules
are maintained (Clearance and Distance tabs). Changes are shown in the
layoutwhenthepolygonisnextcomputed(RATSNESTcommand).
In this way you can also create layers in which several areas are filled
with different signals. In that case you can assign different ranks (priori
-
ties) for the polygons. The rank property determines which polygon is
subtracted from others if they overlap. Rank = 1 signifies the highest
priority in the layout; nothing will be subtracted from such a polygon
(with the exception of polygons with rank = 0, drawn as a part of a
package in the Package Editor). Rank = 6 signifies the lowest priority.
PolygonswiththesamerankarecomparedbytheDRC.
Please read the notes regarding polygons in the section on Defining a
CopperPlane onpage 115.
Do not choose the wire width for polygons too fine! This can lead to
hugeamountsofplotdata andproblemsforthemanufacturingprocess.
Power SupplyLayerwithOneSignal
A power supply layer with one signal is implemented by renaming one
of the Route2...15 layers in such a way that the new name consists of the
corresponding signal name prefixed by a $ sign. If, for example, the sig
-
nal called GND is to be realized as a power supply layer, then a layer is
specifiedashavingthename$GND.
The DISPLAY menu shows only those layers defined in the Layer setup of
theDesignRules!
For this purpose you activate the
DISPLAY command. You select layer 2
from the menu with the mouse. Then
clickonthe Change button.
Enter the signal name for the layer, and
activate the Supply layer check box. If the
layer is to be visible in the layout imme
-
diately, then click also on the Displayed
checkbox.
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EAGLEManual