Altium Designer Documentation

Working with a Fill Object on a PCB in Altium Designer

Created: July 27, 2015 | Updated: October 4, 2016
Now reading version 15.1. For the latest, read: Fill for version 21
All Contents

Parent page: PCB Objects

A placed Fill.


A fill is a rectangular object that can be placed on any layer. When placed on a signal layer, a fill becomes an area of solid copper that can be used to provide shielding or to carry large currents. Fills of varying size can be combined to cover irregularly shaped areas, and can also be combined with track or arc segments and be connected to a net.

Fills can also be placed on non-electrical layers. For example, place a fill on the Keep-Out layer to designate a 'no-go' area for autorouting. Place a fill on a Power Plane, Solder Mask, or Paste Mask layer, to create a void on that layer. In the PCB Library Editor, fills can be used to define component footprints.


Fills are available for placement in both PCB and PCB Library Editors:

  • PCB Editor - the following methods of access are available:
    • Choose Place » Fill from the main menus.
    • Click the  button on the Wiring toolbar.
  • PCB Library Editor - the following methods of access are available:
    • Choose Place » Fill from the main menus.
    • Click the  button on the PCB Lib Placement toolbar.
    • Right-click in the workspace and select Place » Fill from the context menu.


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

  1. Click or press Enter to anchor the first corner of the fill.
  2. Move the cursor to adjust the size of the fill, then click or press Enter to anchor the diagonally-opposite corner and complete placement of the fill.
  3. Continue placing further fills, or right-click or press Esc to exit placement mode.

A fill will 'adopt' a net name if it touches an object which has a net name.

Additional actions that can be performed during placement are:

  • Press the L key to flip the fill to the other side of the board – note that this is only possible prior to anchoring the fill's first corner.
  • Press the + and - keys (on the numeric keypad) to cycle forward and backward through all visible layers in the design respectively – to change placement layer quickly.
  • Press the Tab key to access an associated properties dialog, from where properties for the fill can be changed on-the-fly.
While attributes can be modified during placement (Tab to bring up associated properties dialog), bear in mind that these will become the default settings for further placement unless the Permanent option on the PCB Editor – Defaults page of the Preferences dialog is enabled. When this option is enabled, changes made will affect only the object being placed and subsequent objects placed during the same placement session.

Placing a Fill as a Keepout

A Fill 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 fill is simply a Fill object with its Keepout property enabled, an all-layer keepout is a Fill that has been placed on the Keepout layer.

  • To place a layer-specific keepout either place a standard Fill on the required signal layer and then enable the Keepout property to make it a layer-specific keepout, or use the predefined Fill keepout placement command, available from the Place » Keepout sub-menu.
  • To place an all-layer keepout make the Keepout layer the active layer, then place a standard Fill from the menu.

Graphical Editing

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

When a fill object is selected, the following editing handles are available:

A selected Fill.

  • Click and drag A to resize the fill in the vertical and horizontal directions simultaneously.
  • Click and drag B to resize the fill in the vertical and horizontal directions separately.
  • Click and drag C to rotate the fill about its center point.
  • Click anywhere on the fill – away from editing handles – and drag to reposition it. While dragging, the fill can be rotated or mirrored:
    • Press the Spacebar to rotate the fill anti-clockwise or Shift+Spacebar for clockwise rotation. Rotation is in accordance with the value for the Rotation Step, defined on the PCB Editor – General page of the Preferences dialog.
    • Press the X or Y keys to mirror the fill along the X-axis or Y-axis respectively.

If attempting to graphically modify an object that has its Locked property enabled, a dialog will appear asking for confirmation to proceed with the edit. If the Protect Locked Objects option is enabled on the PCB Editor – General page of the Preferences dialog, and the Locked option for that design object is enabled as well, then that object cannot be selected or graphically edited. Double click on the locked object directly and disable the Locked property or disable the Protect Locked Objects option, to graphically edit the object.

Non-Graphical Editing

The following methods of non-graphical editing are available:

Editing via an Associated Properties Dialog

Dialog page: Fill

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

The Fill dialog.

The Fill dialog can be accessed prior to entering placement mode, from the PCB Editor – Defaults page of the Preferences dialog. This allows the default properties for the fill object to be changed, which will be applied when placing subsequent fills.

During placement, the dialog can be accessed by pressing the Tab key.

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

  • Double-clicking on a placed fill object.
  • Placing the cursor over a fill object, right-clicking and choosing Properties from the context menu.
  • Using the Edit » Change command and clicking once over a placed fill object.

Quickly change the units of measurement currently used in the dialog between metric (mm) and imperial (mil) using the Ctrl+Q shortcut. This affects the dialog only and does not change the actual measurement unit employed for the board, as determined by the Measurement Unit setting in the Board Options dialog (Design » Board Options).

Via an Inspector Panel

Panel page: PCB Inspector, PCB Filter, PCBLIB Inspector, PCBLIB Filter

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 - by using the applicable Filter panel, or the Find Similar Objects dialog - the panel can be used to make changes to multiple objects of the same kind, from one convenient location.

Via a List Panel

Panel page: PCB List, PCB Filter, PCBLIB List, PCBLIB Filter

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 - by using the applicable Filter panel, or the Find Similar Objects dialog - 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.


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