The PCB Auto Router is a feature of the CAD software that places traces automatically, often saving substantial time and effort. You can use the Auto Router to create your circuit initially or to modify a circuit at a later stage. For example, you might might place several footprints for a mini web server circuit, define nets and then run the Auto Router to create your circuit layout.
To use the PCB Auto Router:
- Create nets if not already done.
- Click Tools | Route... The Auto Router dialog appears:
- Enter the desired parameters:
Number of layers
Number of copper layers on which you want to auto-router to place traces - usually "Two sides".
Minimal gap
Minimum distance between conductors. Smaller values improve the chance of fully routing your board.
Width of new traces
Width of traces created during the routing process. Smaller values improve the chance of fully routing your board. This parameter will not affect existing traces.
Number of passes
The number of times the auto router will try to route your board. Higher values improve the chance of fully routing your board but take longer to complete.
Routing grid
Similar to the snap grid, the routing grid specifies the distance between imaginary grid lines along which the auto router will place conductors. Lower values improve the chance of fully routing your board but creates a higher density of traces and takes longer to run.
Obstacle closeness
Lower values improve the chance of fully routing your board but places traces closer to obstacles such as pads.
Trace bend Lower values improve the chance of fully routing your board but increases the number of bends in traces.
Layer change Lower values improve the chance of fully routing your board but increases the number of vias.
- Click OK.
- The Auto Router runs.
- Click OK to exit.
- Any connections the auto router fails to make will be displayed by unresolved Logical Connections lines (if enabled). Create those connections manually.
