Setting Up Board Layers
0:18
What you should do is treat 0.25 mm as your default trace width, enforce 0.15 mm as the minimum only where you truly need to escape fine-pitch pins, and create a separate wider rule for power nets at 0.5 mm. Flux’s trace-width docs explicitly support adding
Trace Width, Trace Width Minimum, and related net/trace rules in the Layout Rules areaPractical setup
| Rule | Value | Use |
|---|---|---|
Default Trace Width | 0.25 mm | Normal signal routing |
Default Trace Width Minimum | 0.15 mm | Fine-pitch escape only |
Power-net Trace Width | 0.5 mm | Battery, charger, regulator outputs, main supply rails |
- 0.25 mm default: good beginner-friendly general signal width.
- 0.15 mm minimum: not your target everywhere, just the narrowest allowed when routing gets tight around IC pins.
- 0.5 mm for power: use on rails that actually carry meaningful current, especially battery and regulator paths.
Since you see:
- Layout default rule
- Trace default rule
I’d do this:
Step 1
Open Trace default rule and set:
Trace Width= 0.25 mmTrace Width Minimum= 0.15 mm
That gives you a sane global baseline using the documented trace-width rule flow
Step 2
For power, don’t try to force the whole board’s default trace width to 0.5 mm. Instead, add a more specific rule for power nets. Flux’s layout workflow is rule-driven and supports selector-based / target-specific rule application rather than only one board-wide width
What if you don’t know how to target power nets yet?
Then for now:
- set the global trace defaults to 0.25 / 0.15 mm
- remember to manually make important power traces wider later
- once your nets exist, create a dedicated rule for nets like:
VBATUSB_5V- regulator outputs
- main 3V3 rails
Best fit for your EEG board
| Net type | Recommended width |
|---|---|
| Fine-pitch IC escape | 0.15 mm |
| Normal digital/control/sensor signals | 0.25 mm |
| General power rails | 0.5 mm |
| Sensitive EEG analog inputs | Keep short first; width is less important than shielding/return path |
Set this now:
- Trace default width = 0.25 mm
- Trace default minimum = 0.15 mm
Then later add:
- Power-net trace width = 0.5 mm
If you want, I can help you write the exact next rule for power once you tell me what options appear when you click Add under rules.
30 days
How do I create multiple schematic sheets in this project and connect them with ports?
30 days
0:27
Reading docs about How do I create multiple schematic sheets in Flux and connect them using ports or net portals between sheets?.
Reading docs about How do net portals work in Flux for connecting signals across modules or multiple schematic sheets?.
Gathering compliance guidance.
This is the most relevant entry I found related to the topic:
Does Flux support multi-sheet schematics or reusable sub-circuits?Flux uses a single-sheet schematic approach. However, you can section your schematic or create Modules—reusable sub-circuits that encapsulate part of your design.How can I label nets or create named connections in the schematic?Use net portals by placing a portal symbol on a wire and entering the desired net name. Any portal sharing that name will automatically connect the nets. Learn more in the Schematic – Net Portals guide.
Show module docs
Net portals steps
Module vs portals
30 days
Welcome 👋
Flux helps you build PCBs faster with an AI teammate!
Create your account to collaborate, stay updated, fork your own version, and get instant answers from our AI agent.