Footprint keepout layer

Question

In general what is the purpose of having a keep out layer in a component footprint? for example in the following components:

There is a layer related to keep out layer as follows:

What is the purpose of this layer?

Answer 1

In general, the keep-out layer represents an area you don't want other things to be.

This might be for a number of reasons:

• Physical -- they don't fit
• Electrical -- prevention of sparks
• Noise -- to keep signals clean
• Aesthetic -- you might not want tracks/vias under some silkscreen

CAD software will give you choices about what to keep out of a zone. This is the user interface from KiCad.

From KiCAD V7