"Subtract" is a function which allows you to subtract "the second selected object" from "the first selected object". This is available in a PCB/panel/footprint sheet and useful when you want to remove unnecessary objects such as silk overlapping with solder resist.

Silk：Board Outline	Plane：Silk	Plane：Route

If you want to edit the objects in a footprint using "Subtract", they will be editable by checking the checkbox of "Enable Component Editing".

Subtracting (Silk：Board Outline)

The following explains how to cut silk that sticks out from board outline using the "Subtract" function.

(1) Select [Edit] -> [Subtract].   * The menu is also selectable from the right-click menu.

(2) Specify a clearance in the Property window.

(3) Select silk as the first object.     => The first selected object will be cut by the second selected object.

(4) Select board outline as the second object.     => The second selected object will cut the first selected object.

The silk will be cut based on the specified clearance value.

 

Usage Example (Plane：Silk)

The following is how to subtract silk characters from a plane.

(1) Select a plane. (Ⓐ) (2) Select silk characters. (Ⓑ)   => The plane will be cut out based on the shape of silk characters.

 

Usage Example(Plane：Route)

The following is how to subtract a route from a plane.

(1) Select a plane. (Ⓐ) (2) Select a route. (Ⓑ)   => The plane will be cut out based on the shape of a route.

 

Selectable Objects in Each Selection

The following list shows the objects that can be selected in the first and second selections in Subtract mode.

Selectable Objects in First Selection

・Route  * A series of routes until a via, pad or junction is encountered will be selected.
・Plane (Dynamic/Static)
・Assembly Area
・Keep Out Area
・Design Rule Area
・Line  * Spread selection
・Rectangle
・Circle
・Arc
・Filled Objects

Selectable Objects in Second Selection

・Pad  * Selected object only
・Via　* Selected object only
・Route  * A series of routes until a via, pad or junction is encountered will be selected.
・Plane (Dynamic/Static)
・Assembly Area
・Keep Out Area
・Design Rule Area
・Line  * Spread selection
・Rectangle
・Circle
・Arc
・Filled Objects
・Text (Text, Reference, Attribute Text)