A layer is one plane of the board. For example the top side silk screen is a layer and the top side copper is another layer. There are several layers:
- The Board layer specifies the edge shape of the board and any cutouts or mounting holes.
- The Top and Bottom layers (also called Signal layers) specify the copper patterns of pads, footprints, traces, etc.
- The Top Silk and Bottom Silk layers specify the silk screen text, outlines, identification codes, etc.
- The Top unMask and Bottom unMask layers specify the shape of the areas of the board to be unmasked by the solder mask. Unmasked regions can be soldered. For example if you draw a small rectangle on the unMask layer a small rectangle of area will not be masked. (The unMask layer is usually created automatically - you will see that pads are generally unmasked.) To unmask an object on top/bottom copper layer, the Edit | Unmask command can be used.
- The Attribute layer specifies identifiers and comments for your own reference and will not be seen or used in the manufacture of your board.
When editing your design you can place objects on any layer. For example, you might want to place a pad on the top copper layer.
- Choose a tool that is appropriate for creating the object such as the trace tool.
- On the Property Bar choose a layer from drop-down list of available layers.
- Place the object.
The bottom layers are shown as if looking thru the top side of a transparent board. You can move an object from one layer to another. For example, you might want to move a surface amount device from the top copper layer to the bottom copper layer.
- Select the object(s) to move.
- On the Property Bar Layer drop-down list choose the desired layer.
When trace segments are moved between layers, Pad2Pad automatically creates via-holes to maintain electrical connections.
You can show or hide layers from view. For example, it can be helpful to hide all layers except the copper layers to avoid distractions while checking your board prior to placing an order.
- On the left toolbar click the Layers button.
- Click the corresponding checkmark in the Visible column.
- OR -
Click the Visible column header to turn on/off all layers.
You can change the colors of each layer. For example you might prefer blue to green for the top copper layer.
- In the Layers dialog, select a layer to change.
- From the color drop list choose the desired color.