Routing

Routing, of course, is an essential part of a circuit board. PCBmodE does not have an auto-router, and routing is typically done in Inkscape, although theoretically, routing can be added manually in a text editor. All routing shapes reside in the routing SVG layer of each PCB layer.

Important

Make sure that you place the routes and vias on the routing SVG layer of the desired PCB layer. To choose that layer either click on an element in the layer or open the layer pane by pressing CTRL+SHIFT+L.

Important

In order to place routes, make sure that Inkscape is set to ‘optimise’ paths by going to File->Inkscape Preferences->Transforms and choosing optimised under Store transformation.

Adding routes

Choose the desired routing SVG layer. Using the Bezier tool (SHIFT+F6) to draw a shape.

For a filled shape, make sure that it is a closed path and in the Fill and stroke pane (SHIFT+CTRL+F) click on the flat color button on the Fill tab, and the No paint (marked with an X) on the Stroke point tab.

For a stroke, in the Fill and stroke pane (SHIFT+CTRL+F) click on the No paint button on the Fill tab, and the Flat color on the Stroke point tab. Adjust the stroke thickness on the Stroke style tab.

Note

Shapes can be either stroke or fill, not both. If you’d like a filled and stroked shape, you’ll need to create two shapes.

Finally, you must move the shape with the mouse or with the arrows.

Note

When creating a new shape Inkscape adds a matrix transform, which is removed when the shape is moved because of the optimise settings as described above. This minor inconvenience is a compromise that greatly simplifies the extraction process.

If the route is placed where there is a copper pour, it will automatically have a buffer around it that’s defined in the board’s configuration. Sometimes, it is desirable to reduce or increase this buffer, or eliminate it completely in order to create a bridge (for example when connecting a via to a pour). This is how it is done:

  1. Choose the route
  2. Open Inkscape’s XML editor (SHIFT+CTRL+X)
  3. On the bottom right, next to set remove what’s there and type in pcbmode:buffer-to-pour
  4. In the box below type in the buffer in millimeters (don’t add ‘mm’) that you’d like, or 0 for none
  5. Press set or CTRL+ENTER to save that property

Tip

Once you’ve created one route, you can simply cut-and-paste it and edit it using the node tool without an additional settings. You can even cut-and-paste routes from a different design.

Adding vias

Vias are components just like any other. There are placed just like other components, but in the routing file ``<design_name>_routing.json”, not the main board’s JSON.

You can assign a unique key to the via, but that will be over-written by a hash when extracted.

Note

Since vias are components, anything could be a via, so if it makes sense to place a 2x2 0.1” header as a “via”, that’s possible.

Important

Don’t forget to extract the changes!