KiCAD Design Rules

The design rules describe how small the traces and drill holes can be, and we can’t guarantee that your board will work correctly if you ignore them. It’s best to set the design rules as soon as you start a new board layout in PCBNew, and to run the Design Rules Check before you generate the gerbers.

KiCAD doesn’t let you import a design rules file so you have to manually set the rules each time you start.

Set Measurements

First, select Preferences -> General from the menu to set Imperial or Metric.

I’ve chosen to use Imperial measurements. You can change it back to Metric once you’ve set the design rule limits, since KiCAD will convert automatically.

Design Rules Editor

Open the Design Rules Editor by going to Design Rules -> Design Rules in the top menu. The Design Rules Editor has two sections, and you’ll want to edit both.

In the Global Design Rules, disable the Blind/Buried and Micro vias. You can specify custom via sizes if you like, but it’s not necessary. I’m using the limits of our 2 layer boards service.

Design Rules Editor - Global Design Rules section

In the Net Classes Editor tab, you have to put something in the uVia Dia and uVia Drill sections. You can ignore any nets under Membership for now.

Design Rules Editor - Net Classes Editor section

Layer Setup

Under Design Rules -> Layer Setup is a list of layers that you can Enable or Disable. I usually turn off the layers that we don’t need to fabricate the boards.

Once you select those and hit ‘OK’, KiCAD will update the list of Visibles layers on the right. We generally need the Top and Bottom copper, mask, and silk. We also need the board outline by itself on the Edge.Cuts layer so the fab can route the board.

You’ll probably want the Paste layers to create a stencil if you’re working with surface mount components.

It’s fine to enable the Adhesive, Fab, Courtyard, and other layers while you’re designing. When you submit the gerbers, though, please leave those out of the zip file.

Layer Setup showing the minimum list of layers we need

Template

KiCAD supports creating templates, which are essentially empty new projects with the design rules already loaded. We recommend reading the official documentation along with a helpful thread on the KiCAD users forum that includes a link to an example template.