Nets and Traces

When creating traces for a PCB, often times you will need to increase or decrease the size of the traces for a specific net. This can be done either through the specific net itself or, if you need to apply the size change to several nets, using rulesets.

What Is a Net?

Nets are a collection of electrically connected nodes in PCB design software. They represent paths for electrical signals to travel between components on the board. Every terminal on a PCB design program is connected to a net, and (unless in the case of high frequency transmission lines) all points on a net should share the same voltage. Nets oftentimes are named for easy identification and organizational purposes. Nets are used to generate netlists, which is a list of all the electrical connections to each component in the design.

What is a Trace?

Whereas a net represents the logical collection of nodes with a shared electrical connection, a trace is the physical conductive pathways that actually connects the individual components. A single net may represent the electrical connection of multiple components all sharing a single voltage value. This net, however, would be composed of multiple traces.

Traces are typically made of copper and can vary in widths depending on the desired current carrying capacity.

Trace and Net Specific Rules

Flux contains other related rules that allow you to further customize the behavior of traces and nets, listed below. See the complete list of rules for further information and examples for using each.

• Fill stitching density: creates vias in a ground or power net fill, known as fill stitching.
• Fill stitching offset: allows for offsetting fill stitching.
• Preferred trace width: allows for presetting trace-widths for easy toggling during routing.
• Trace shape: defines the shape of a trace, either curved or arced.
• Trace width: sets the width of a trace (or collection of traces).

Naming and Renaming Nets

To keep your design organized and make debugging easier, you can rename nets to something more descriptive than the default auto-generated names. In Flux, you can do this by selecting the net from the Object Tree, then updating the “Designator” field in the Inspector panel. Giving nets intuitive names (like VCC, GND, or UART_TX) makes it easier to apply rules, track signal paths, and communicate design intent with your team.

Deleting Traces

Whether you're cleaning up a few connections or doing a full reroute, there are two ways to delete traces in Flux:

Delete single traces

Click to select the trace, then press Del, or right-click and choose Delete.

Delete multiple traces using the Objects panel

Open the Objects panel on the right:

• To remove all traces under a specific net, expand the net in the list, select the traces, and press Del.
• To wipe out all traces, type "trace" in the search bar, select the first result, hold Shift, scroll down, select the last one, and press Del.