Working with a Region Object on a PCB in Altium Designer

Parent page: PCB Objects

Examples of the various types of placed region objects.

Summary

A Region, also known as a Solid Region, is a polygonal-shaped primitive object that can be placed on any layer. It can be configured to be positive, for example placed as a copper region; or negative, for example placed as a polygon pour cutout. By placing it as a negative on the multi-layer, it can be placed as a board cutout.

A region can have any number of sides and vertices (corners). It can be placed on a signal layer to define an area of solid copper, to be used to provide shielding or to carry large currents. Positive regions can be combined with tracks or arc segments and be connected to a net. In the PCB Library editor regions can be used to create custom pad shapes on copper layers, or special mask shapes on the solder and paste masks. On non-electrical layers regions can be used to define custom shapes for tasks such as logos.

A region can also be used to define no-go areas for component placement and routing, which are also known as keep-outs. These can apply to all layers by placing the region on the Keep-out layer, or they can be layer-specific by placing the region on a signal layer and enabling the Keep-out option for that region.

When placed as a negative, a region can create a cutout (a void) in a polygon pour. In this mode the region will not be filled with copper when the polygon is poured. When used as a negative region for a board cutout (by placing it on the multi-layer), it defines an area that becomes a hole through the finished board. Board cutout regions are transferred to Gerber and ODB++ files for manufacturing purposes.

Availability

Regions are available for placement in both the PCB editor and the PCB Library editors by selecting Place » Solid Region from the main menu.

Placement

After launching the command, the cursor will change to a crosshair and you will enter region placement mode. Placement is made by performing the following sequence of actions:

1. Position the cursor and click to anchor the starting vertex for the region.
2. Move the cursor ready to place the second vertex. The default behavior is to place 2 edges with each click, with a user-defined corner shape between them. Refer to the Placement Modes topic below for more details on changing corner modes.
3. Continue to move the mouse and click to place further vertices.
4. After placing the final vertex, right-click or press Esc to close and complete placement of the region. There is no need to manually close the region as the software will automatically complete the shape by connecting the start point to the final point placed.
5. Continue placing further regions, or right-click or press Esc to exit placement mode.

Additional actions that can be performed during placement include:

• Press the + and - keys on the numeric keypad to cycle forward and backward through all layers currently visible in the design.
• Press the * key to cycle through the visible signal layers.
• Press the Tab key to access an associated properties dialog, from where properties for the region can be changed on-the-fly.

Placement Modes

While placing a region there are 5 available corner modes, 4 of which also have corner direction sub-modes. During placement:

• Press Shift+Spacebar to cycle through the 5 available corner modes: 45 degree, 45 degree with arc, 90 degree, 90 degree with arc, and Any Angle.
• Press 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.
• Press the 1 shortcut key to toggle between placing 2 edges per click, 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 5 available corner modes, press the 1 shortcut to toggle placement between 2 edges or 1 edge.

Placing a Region as a Keepout

A region can be placed as a layer-specific keepout object or an all-layer keepout to act, for example, as a placement or routing barrier. Objects defined as keepouts are ignored during output generation, such as photo plotting and printing. A layer-specific keepout region is simply a region object with its Keepout property enabled, an all-layer keepout is a region that has been placed on the Keepout layer.

1. To place a layer-specific keepout either place a standard region on the required signal layer and then enable the Keepout property to make it a layer-specific keepout, or use the predefined Solid Region keepout placement command, available in the sub-menu in main menu at Place » Keepout » Solid Region.
2. To place an all-layer keepout, make the Keepout layer the active layer, then place a region from the menu (Place » Keepout » Solid region).

Placing a Region as a Polygon Cutout

A Region can also act as a polygon cutout. To place a polygon cutout:

1. Place a standard region over the polygon and then enable the Polygon Cutout option in the dialog to achieve this.
2. Repour the polygon to pour around the new cutout using one of the Repour commands available in main menu at Tools » Polygon Pours.

Placing a Region as a Board Cutout

A Region can also act as a board cutout. To place a board cutout:

1. Place a standard region over the board shape and then edit the region and enable the Board Cutout option in the dialog to achieve this, or,
2. Place a board cutout directly via the menu at Design » Board Shape » Define Board Cutout.
3. Repour any polygons that overlay the board cutout using one of the Repour commands available on the menu at Tools » Polygon Pours.

Graphical Editing

This method of editing allows you to select a placed region object directly in the workspace and change its size, shape or location, graphically.

Click once on a region object to select it, which puts it into edit mode. The outer shape of the region object is defined by a series of edges: where each edge is represented by an end vertex at each end, shown as a solid white square; and a center vertex in the middle, shown as a hollow white square. Each end vertex represents the location where 2 edges meet.

A selected Region.

• Click and drag A to move the applicable end vertex.
• Click and drag B to move the applicable center vertex, effectively creating a new end vertex, and splitting the original edge into two.
• Click anywhere along an edge, away from editing handles, and drag to slide that edge.
• Ctrl+click anywhere along an edge, away from editing handles, to insert a new end vertex.
• Click and hold on an end vertex, and press Delete, to remove that vertex.
• Click anywhere on the region – away from editing handles – and drag to reposition it. While dragging, the region can be rotated or mirrored:
  • Press the Spacebar to rotate the region anti-clockwise or Shift+Spacebar for clockwise rotation. The Rotation Step size is defined on the PCB Editor – General page of the Preferences dialog.
  • Press the X or Y keys to mirror the region along the X-axis or Y-axis respectively.

Non-Graphical Editing

The following methods of non-graphical editing are available:

Editing via an Associated Properties Dialog

Dialog page: Region

This method of editing uses the following dialog to modify the properties of a region object.

The Region dialog.

The Region dialog can be accessed during placement by pressing the Tab key.

After placement, the dialog can be accessed in one of the following ways:

• Double-clicking on the placed region object.
• Placing the cursor over the region object, right-clicking and choosing Properties from the context menu.

When editing a Polygon Cutout via the Region dialog, the only properties available for editing are Layer an Vertices.

Editing via an Inspector Panel

Panel pages: PCB Inspector, PCBLIB Inspector

An Inspector panel enables the designer to interrogate and edit the properties of one or more design objects in the active document. Used in conjunction with appropriate filtering, the panel can be used to make changes to multiple objects of the same kind, from one convenient location.

Editing via a List Panel

Panel pages: PCB List, PCBLIB List

A List panel allows the designer to display design objects from one or more documents in tabular format, enabling quick inspection and modification of object attributes. Used in conjunction with appropriate filtering, it enables the display of just those objects falling under the scope of the active filter – allowing the designer to target and edit multiple design objects with greater accuracy and efficiency.