Applied Parameters: None
This command is used to place a Polygon Pour object onto the active document. Polygon pours are used to create a solid or hatched (lattice) area on a PCB layer. Also referred to as copper pours, polygon pours are used to fill irregularly shaped areas of a board, automatically pouring around existing objects and connecting only to objects on the same net as the polygon pour. A polygon pour is a group design object - that is, it is made up of simpler primitive objects, either regions, or tracks and arcs.
On a signal layer, you can place a solid polygon pour to define an area for carrying large power supply currents, or as a ground-connected area for providing electro-magnetic shielding. Hatched polygon pours are commonly used for ground purposes in analog designs.
This command can be accessed from the PCB Editor by:
- Choosing the Place » Polygon Pour command from the main menus.
- Locating and using the Polygon Pour command () on the Active Bar.
- Clicking the button on the Wiring toolbar.
- Right-clicking then choosing the Place » Polygon Pour command from the context menu.
After launching the command, the cursor will change to a crosshair, and you will enter polygon placement mode. At this point, it can be a good idea to access the polygon pour's properties to set a few things in advance of defining the shape of the pour. To do so, press the Tab key to access the Properties panel, from where properties for the polygon pour can be changed on-the-fly. Pressing Tab pauses placement, allowing you to interact with the panel (or other area of the software) directly. To resume, click the pause symbol that appears over the workspace.
Define a few key properties of the Polygon before defining its shape.
- Select the polygon Fill Mode; these are discussed in more detail below.
- Select the required net in the Net drop-down.
- Note that each polygon has a Name, a system-defined name will be based on the layer and the net; enter your preferred Name. Alternatively, enable the Auto Naming option to have automatic polygon naming applied to the polygon. Naming is based on the chosen naming template, specified using the Polygon Naming Scheme field in the Properties panel (when no objects are selected in the workspace). The name is based on the layer, the connected net, and a unique numerical index.
Typically that is all that needs to be set before defining the shape of the polygon itself - click the pause symbol that appears over the workspace to define the polygon shape.
- Position the cursor then click to anchor the starting vertex for the polygon.
- Move the cursor to place the second vertex. The default behavior is to place two edges with each click with a user-defined corner shape between them. Refer to the Placement Modes section below for more details on changing corner modes.
- Continue to move the mouse then click to place further vertices.
- After placing the final vertex, right-click or press Esc to close and complete placement of the polygon. There is no need to manually close the polygon as the software will automatically complete the shape by connecting the start point to the final point placed.
- While placing a polygon there are five available corner modes, four of which also have corner direction sub-modes. During placement:
- Press Shift+Spacebar to cycle through the five available corner modes: 45 degree, 45 degree with arc, 90 degree, 90 degree with arc, and Any Angle.
- Press the Spacebar to toggle between the two corner direction sub-modes.
- When in either of the arc corner modes, hold the or keys to shrink or grow the arc. Hold the Shift key as you press to accelerate arc resizing.
- For all corner modes except Any Angle, press the 1 shortcut key to toggle between placing two edges per clic, or one edge per click. In this second mode the dashed edge is referred to as the look-ahead segment (as shown in the last image in the set below).
- Press the Backspace key to remove the last vertex.
Press Shift+Spacebar to cycle through the five available corner modes, press the 1 shortcut to toggle placement between
two edges or one edge (for all modes except Any Angle).
Polygon Fill Modes
The polygon pour placement engine can construct polygons from either solid regions or from a combination of tracks and arcs. To help you decide which of these to use, consider the following:
- Region based polygons (Fill Mode set to Solid (Copper Regions)) result in far fewer objects being placed making for: smaller files; faster redraws, file opening, DRC and net connectivity analysis; and smaller output files as the region object is fully supported in Gerber and ODB++.
- Track/Arc based polygons (Fill Mode set to Hatched (Tracks/Arcs)) allow a hatched polygon to be created by setting the Track Width to be smaller than the Grid Size. Note that they can also be solid by setting the Track Width to be larger than the Grid Size.
- Outline Only polygons (Fill Mode set to None (Outlines)) are Track/Arc polygons without the internal tracks and arcs.
The same Polygon, poured using regions then poured using tracks/arcs.
- Auto-assigned names are continually monitored and managed by the software. If an attribute changes, such as the net assignment or the position of the layer in the layer stack, the auto-assigned name is automatically updated. Affected design rules are also automatically updated.
- As well as interactively placing a polygon, it can also be created from a set of existing track and arc objects that define a closed shape. To define a polygon from an existing closed shape, select all primitives that form the closed shape, then choose the Tools » Convert » Create Polygon from Selected Primitives command from the main menus.
- A new polygon pour can also be created from an existing polygon pour or from the board outline, using the Polygon Pour Manager dialog.
- A polygon pour can be converted to its constituent primitive objects using the Tools » Convert » Explode Polygon to Free Primitives command. Solid polygons will revert to region primitives, while hatched polygons will revert to tracks and arcs. Once exploded, a polygon pour object can no longer be manipulated as a group object.