Library Layers

Library layers are used to place individual items when building component footprints or padstacks. An example of library layers is shown below.

Figure 1: Library Layers

Layer Name

User definable layer name.

Defines the layer type of the library layer. This can be set to the following:

Component Area: contains areas of components that are checked using the DRC command. The heights of components are also checked if a 3D model is not found.
Conductor: used for conductors. Multiple conductor layers can be specified.
Hole: used for holes. Only one Hole layer is permitted in a board design.
Inhibit: used for keepout areas between tracks, between vias, and between tracks and vias.
Metal Mask: used for metal mask (Solder Paste) data.
Non-circular hole: used for cutouts. Only one Non-circular hole layer is permitted in a board design.
Solder Resist: used for solder resist data.
Symbol Mark: used for symbol mark (Silkscreen, Assembly outlines) data.
User defined: additional layers that you define. These are commonly used for notes or dimension data. Multiple user-defined layers can be specified.

The preview color for padstacks can be specified for each layer. The preview color is displayed in the Padstack Editor preview.

Note

As a minimum requirement in Footprint Editor, two component area layers and one hole layer are required.
Library layers should be defined to suit both Surface Mount Technology (SMT) and Plated Through-Hole (PTH) components. An example is shown below.
Keep the number of layers in the library to a minimum.
Use "one-to-many" layer mapping whenever possible.
As library layers do not relate directly to the PCB technology layers, mapping is required. The mapping is covered in the Technology and Design Rule Editors training.

Figure 2: Example of Library Layers