Arc (PCB)

 
The Arc dialog, as accessed while placing a standard Arc (left) and as access while placing a Keeptout Arc (right).

Summary

This dialog allows the designer to specify the properties of an Arc object. An Arc is a primitive design object, used to create curved shapes on a single layer of a PCB. This could include: curved corners in the routing, a circular ring on the component overlay, or a curved edge on a keepout zone.

Access

The Arc 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 arc object to be changed, which will be applied when placing subsequent arcs.

During placement (Place » Arc (Center, Edge, Any Angle, or Full Circle) or Place » Keepout » Arc (Center, Edge, Any Angle, or Full Circle)), the dialog can be accessed by pressing the Tab key.

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

• Double-clicking on an Arc object.
• Placing the cursor over an Arc, right-clicking and selecting the Properties command from the context menu.
• Using the Edit » Change command and clicking once over the placed arc object.

Options/Controls

• Radius - The radius of the Arc, measured from the center point, to the center of the Arc line.
• Width - The width of Arc line.
• Start Angle - The start angle of the Arc, measured from the X axis in the first quadrant (plane geometry).
• End Angle - The end angle of the Arc.
• Center X/Y - The X/Y location of the Arc center.

Properties

• Layer - The layer that the Arc is placed on. Arcs can be placed on any layer other than the system layers.
• Locked - Lock the object so that it cannot be edited graphically.

• Net - If the Arc is a copper object, choose a Net for the Arc. All Nets in the current project will be listed in the drop-down list.
• Solder Mask Expansion - This field allows you to enable and control the expansion to be used with respect to the arc on the Solder Mask layer, to create the required opening in the mask. This opening can be larger (a positive expansion value) or smaller (a negative expansion value) than the arc itself. The following options are available:
  • No Mask - No opening in the solder mask.
  • Expansion value from rules - Choose this option to have the solder mask expansion for the arc follow the defined value in the applicable Solder Mask Expansion design rule.
  • Specify expansion value - Choose this option to override the applicable design rule and specify the solder mask expansion value for the arc.
• Paste Mask Expansion - This field allows you to enable and control the expansion to be used with respect to the arc on the Paste Mask layer, to create the required opening in the mask. This opening can be larger (a positive expansion value) or smaller (a negative expansion value) than the arc itself. The following options are available:
  • No Mask - No opening in the paste mask.
  • Expansion value from rules - Choose this option to have the paste mask expansion for the arc follow the defined value in the applicable Paste Mask Expansion design rule.
  • Specify expansion value - Choose this option to override the applicable design rule and specify the paste mask expansion value for the arc.

Keepout Properties

• Restricted for Layer - Click to open the drop-down menu and select which layer the Keepout is restricted for.
• Locked - Lock the object so that it cannot be edited graphically.
• Keepout Restrictions - Select which primitives are affected by the keepout restrictions.