Copper Thieving

Copper Thieving adds a copper fill to the empty areas of a Gerber copper layer. The fill keeps a set clearance from the traces. Use it to balance the copper of a board, or to add a robber bar and a pattern plating mask for hole plating.

Where to find it

• Menu: Plugins > Copper Thieving.
• Keyboard: Alt+J.
• Toolbar: Thieving button in the Plugin toolbar.
• The panel opens in a tab next to Project and Properties. The tab shows the plugin name.

Screenshot placeholder: images/Copper-Thieving-1.png — the Copper Thieving panel with the Source Object, Thieving Parameters and the Insert Copper thieving button visible.

Quick start

1. Select the copper Gerber object in Source Object.
2. Set Clearance to the gap you want between the fill and the traces (mm or inch).
3. Set Margin and Area.
4. Keep Reference as Itself and Fill as Solid.
5. Click Insert Copper thieving.
6. The new object is named <source name>_thief. Check it on the canvas.

Screenshot placeholder: images/Copper-Thieving-2.png — the canvas with the source copper and the new _thief object shown.

Parameters

Source Object

Parameter	Description	Default
Source Object	The Gerber object that receives the copper thieving. Only Gerber objects are listed.	—

Thieving Parameters

Parameter	Description	Default
Clearance	Distance between the thieving elements and the copper traces of the Gerber. The fill can split into several polygons. Range: 0.00001 to 10000 (mm or inch).	0.25 mm
Margin	Bounding box margin. It grows the reference area. Range: 0 to 10000 (mm or inch).	1.0 mm
Area	Thieving areas with an area smaller than this value are not added. Unit: mm² (or in²).	0.1 mm²
Reference	The area in which the copper thieving is added. Choices below.	Itself
Reference = Itself	The copper thieving extent is based on the extent of the source object.	—
Reference = Area Selection	Left-click on the canvas to start the selection of the area to fill.	—
Reference = Reference Object	The fill is added inside the area of another object. Shows the Type and object selectors.	—
Type	The type of the reference object: Gerber, Excellon or Geometry. Shown only for Reference Object.	Gerber
Reference object selector	The object used as the reference. It has no label. Shown only for Reference Object.	—
Box Type	Shape of the bounding box. Shown only for Itself. Choices below.	Rectangular
Box Type = Rectangular	The bounding box is a rectangle.	—
Box Type = Minimal	The bounding box is the convex hull of the object.	—
Fill	The pattern of the thieving. Choices below.	Solid
Fill = Solid	The thieving is one solid polygon.	—
Fill = Dots Grid	The empty area is filled with a pattern of dots.	—
Fill = Squares Grid	The empty area is filled with a pattern of squares.	—
Fill = Lines Grid	The empty area is filled with a pattern of lines. Works only with Itself.	—

Dots Grid Parameters (shown for Dots Grid)

Parameter	Description	Default
Dia	Diameter of each dot. Range: above 0 to 10000 (mm or inch).	1.0 mm
Spacing	Distance between two dots.	2.0 mm

Squares Grid Parameters (shown for Squares Grid)

Parameter	Description	Default
Size	Side length of each square. Range: above 0 to 10000 (mm or inch).	1.0 mm
Spacing	Distance between two squares.	2.0 mm

Lines Grid Parameters (shown for Lines Grid)

Parameter	Description	Default
Size	Thickness of each line. Range: above 0 to 10000 (mm or inch).	0.25 mm
Spacing	Distance between two lines.	2.0 mm

Buttons (thieving)

Button	Description
Insert Copper thieving	Creates the new object <source name>_thief with the fill polygons.

Robber Bar Parameters

The robber bar is a copper border around the object. It helps in pattern hole plating.

Parameter	Description	Default
Margin	Bounding box margin of the robber bar.	1.0 mm
Thickness	Thickness of the robber bar. Must be above zero.	1.0 mm
Insert Robber Bar	Adds a polygon with the set thickness. It surrounds the object at the set distance.	—

Pattern Plating Mask

Parameter	Description	Default
Source Object	The Gerber object with the soldermask. The plating mask is based on it.	—
Only Pads	Use only the pads when the selected object is a copper Gerber.	Checked
Clearance	Distance between the thieving elements or robber bar and the openings in the mask. Range: -10000 to 10000 (mm or inch).	0.0 mm
Plated area	Read-only. The area that pattern plating covers, from the mask openings. Unit: cm² (or in²). The value is an estimate. The area is a bit larger than the pads because the mask openings are larger than the pads.	—
Add	Which extra geometry is added to the mask. Choices below.	Both
Add = Both	Adds the thieving and the robber bar.	—
Add = Thieving	Adds only the copper thieving.	—
Add = Robber bar	Adds only the robber bar.	—
Add = None	Adds neither.	—
Generate pattern plating mask	Adds the geometry of the thieving and/or the robber bar to the soldermask Gerber.	—

Tool Buttons

Button	Description
Reset Tool	Resets the tool parameters to their default values.

Screenshot placeholder: images/Copper-Thieving-3.png — the Fill combo open, with the Dots Grid Parameters frame visible.

Advanced

• Lines Grid works only with Itself. When you select Lines Grid, the Reference changes to Itself and a warning appears. When you select Area Selection or Reference Object while Lines Grid is active, the Reference returns to Itself.
• The step between two grid cells is Size plus Spacing. The grid is centered in the area.
• The Clearance value grows each copper feature of the source. The fill is the remaining empty area.
• The Area value removes small fill polygons after the clearance is applied.
• The circle quality for dots and robber bar comes from the preference tools_copper_thieving_circle_steps (default 16). It is not on the panel.
• There is no Tcl command for this tool.

See also

• Fiducials
• Markers
• Punch Gerber
• Gerber Object
• Objects Overview
• Preferences Plugins
• Keyboard Shortcuts