Choose Drawing Layer
The LAYER command with one parameter is used to change the current layer, i.e. the layer onto which wires, circles etc. will be drawn. If LAYER is selected from the menu, a popup menu will appear in which you may change to the desired layer. If entered from the command line, 'layer_number' may be the number of any valid layer, and 'layer_name' may be the name of a layer as displayed in the popup menu.
Certain layers are not available in all modes.
Please note that only those signal layers (1 through 16) are available that have been entered into the layer setup in the Design Rules.
Define Layers
The LAYER command with two parameters is used to define a new layer or to rename an existing one. If you type in at the command prompt e.g.
LAYER 101 SAMPLE;you define a new layer with layer number 101 and layer name SAMPLE.
If a package contains layers not yet specified in the board, these layers are added to the board as soon as you place the package into the board (ADD or REPLACE).
The predefined layers have a special function. You can change their names, but their functions (related with their number) remain the same.
If you define your own layers, you should use only numbers greater than 100. Numbers below may be assigned for special purposes in later EAGLE versions.
Delete Layers
The LAYER command with the minus sign and a layer_number deletes the layer with the specified number, e.g.
LAYER -103;deletes the layer number 103. Layers to be deleted must be empty. If this is not the case, the program generates the error message
"layer is not empty: #"
where "#" represents the layer number. If you want to avoid any error messages in a layer delete operation you can use the '??' option. This may be useful in scripts that try to delete certain layers, but don't consider it an error if any of these layers is not empty or not present at all.
The predefined standard layers cannot be deleted.
Supply Layers
Layers 2...15 are treated as supply layers if their name starts with the '$' character and there is a signal with an identical name but without the leading '$'.
Any pads or vias belonging to that signal are implicitly considered connected by the RATSNEST command and the Autorouter.
Supply layers are viewed "inverted", which means that any objects visible on such a layer will result in "copper free" areas on the board. The program automatically generates Thermal and Annulus objects to connect and isolate pads and vias to/from these layers.
You should not draw any additional objects into a supply layer, except, for instance, wires along the outlines of the board, which prevent the copper area from extending to the very edges and thus possibly causing short circuits through a metal casing or mounting screw. Note that there are no checks whether a supply layer really connects all pads and vias. If e. g. a user drawn object isolates a pad that should be connected to the supply layer, there will be no airwire generated for that (missing) connection. The same applies if several Annulus symbols form a "ring" around a Thermal symbol (and would thus completely isolate that pad from its signal). Also note that the size of the annulus symbols used in a supply layer is only derived from the value given under "Annulus" in the "Supply" tab of the Design Rules, and that neither the minimum distances under "Clearance" nor those in the net classes go into this calculation.
For a safer and more flexible way of implementing supply layers you should use the POLYGON command.
Predefined EAGLE Layers
Layout
| 1 Top | Tracks, top side |
| 2 Route2 | Inner layer (signal or supply) |
| 3 Route3 | Inner layer (signal or supply) |
| 4 Route4 | Inner layer (signal or supply) |
| 5 Route5 | Inner layer (signal or supply) |
| 6 Route6 | Inner layer (signal or supply) |
| 7 Route7 | Inner layer (signal or supply) |
| 8 Route8 | Inner layer (signal or supply) |
| 9 Route9 | Inner layer (signal or supply) |
| 10 Route10 | Inner layer (signal or supply) |
| 11 Route11 | Inner layer (signal or supply) |
| 12 Route12 | Inner layer (signal or supply) |
| 13 Route13 | Inner layer (signal or supply) |
| 14 Route14 | Inner layer (signal or supply) |
| 15 Route15 | Inner layer (signal or supply) |
| 16 Bottom | Tracks, bottom side |
| 17 Pads | Pads (through-hole) |
| 18 Vias | Vias (through-hole) |
| 19 Unrouted | Airwires (rubberbands) |
| 20 Dimension | Board outlines (circles for holes) |
| 21 tPlace | Silk screen, top side |
| 22 bPlace | Silk screen, bottom side |
| 23 tOrigins | Origins, top side |
| 24 bOrigins | Origins, bottom side |
| 25 tNames | Service print, top side |
| 26 bNames | Service print, bottom side |
| 27 tValues | Component VALUE, top side |
| 28 bValues | Component VALUE, bottom side |
| 29 tStop | Solder stop mask, top side |
| 30 bStop | Solder stop mask, bottom side |
| 31 tCream | Solder cream, top side |
| 32 bCream | Solder cream, bottom side |
| 33 tFinish | Finish, top side |
| 34 bFinish | Finish, bottom side |
| 35 tGlue | Glue mask, top side |
| 36 bGlue | Glue mask, bottom side |
| 37 tTest | Test and adjustment inf., top side |
| 38 bTest | Test and adjustment inf. bottom side |
| 39 tKeepout | Nogo areas for components, top side |
| 40 bKeepout | Nogo areas for components, bottom side |
| 41 tRestrict | Nogo areas for tracks, top side |
| 42 bRestrict | Nogo areas for tracks, bottom side |
| 43 vRestrict | Nogo areas for via-holes |
| 44 Drills | Conducting through-holes |
| 45 Holes | Non-conducting holes |
| 46 Milling | Milling |
| 47 Measures | Measures |
| 48 Document | General documentation |
| 49 Reference | Reference marks |
| 51 tDocu | Part documentation, top side |
| 52 bDocu | Part documentation, bottom side |
Schematic
| 91 Nets | Nets |
| 92 Busses | Buses |
| 93 Pins | Connection points for component symbols |
| with additional information | |
| 94 Symbols | Shapes of component symbols |
| 95 Names | Names of component symbols |
| 96 Values | Values/component types |
| Index | Copyright © 2005 CadSoft Computer GmbH |