Layout Rules Reference
Set a PCB constraint once, and it applies to every object that it matches. Layout rules keep trace widths, clearances, and other values consistent across the board.
In Flux, layout rules act as design guardrails and also modify the design directly. For quick changes to one object, use the toolbar. This page explains the different ways to apply rules and their properties.
Layout Rules Types
There are two types of layout rules depending on how they are applied to the target object(s).
Object-specific layout rules: Only apply to the selected object. They can be accessed in the inspector menu on the right after selecting any object.
Selector-based layout rules: Apply to every object that matches the selection criteria. They can be accessed from the "Rules" menu on the left.
Add a rule to one object
Object-specific layout rules apply only to the selected object. To apply a rule to more than one object, use Selector-Based Layout Rules.
Ask Flux to add a layout rule to one object. Name the object by its designator or net name, and tell Flux the value.
You can also do it in the editor.
Use the toolbar
For one object, the fastest way to change layout properties is the toolbar. The toolbar shows automatically when you select an object in the PCB editor.
Use the inspector panel
To add an object-specific rule in the inspector panel:
Select an object.
Find Layout rules in the right-side panel.
Click Edit → Add.
Search for the rule and add it.
Inspect system defaults
System defaults supply the base layout rules for the board. Open the PCB view, then select Profile → System Defaults in the project drawer.
Expand System Defaults to see the default rule sets.
Expand Nets to see the net rule sets, including rules for current, impedance, and differential pairs.
Select a rule set to inspect its values in the Inspector.
Use object-specific rules or selector-based rules to set project values. See inheritance and precedence for how project rules take priority over defaults.
Layout Rules List
The Layout Rules List shows all available layout rules in Flux, with examples.
Layout Rules Modifiers
Flux has a variety of supplemental rule modifiers. These are useful for tweaking the behavior of the target rule.
Layout Rules Inheritance and Precedence
Layout rules might apply differently to objects depending on how they've been defined, and the type of rule. Learn how inheritance and precedence work.
What's Next
Now that you understand the basics of layout rules in Flux, you might want to explore:
PCB Layout Rule Selectors - Understand how to create rules that apply to multiple objects
Layout Rules Types - Explore all available layout rules in Flux