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Contents

• Prerequisites
• KiCad PCB Basics
  • Importing Footprints
  • Assigning Footprints
  • Using PCB Editor
• Trace Width

Prerequisites

KiCad Schematic Design

KiCad PCB Basics

While it is possible to manually manage the creation of a PCB entirely manually, doing everything yourself, it is also possible to integrate everything together with the schematic in order to save time, reduce error and make it easier to edit. This section is dedicated to that latter process, involving the modification of some schematics slightly to enable them to forward edit the PCBs.

A demonstration can be found below: https://drive.google.com/drive/u/2/folders/12cfIS6J14FzGBSDxnJZdtPBbDrg4W0i6

Importing-Footprints

1. When you downloaded and extracted the schematic symbol, you should also have downloaded the footprint for that specific part as well. When extracted it should remain in a very similar location to the symbol's.

2. Adjacent to symbol library browser at the top of the schematic, open footprint editor. From there, you should hit import from file at the top left. The footprint should now be visible.

3. If you already have a footprint library created for the project skip this step. If not, you should, under file, create a new local library (global might work on your end, but not on mine) where you can store the imported footprint.

4. Hit save as, and select the created library as where you want to store the footprint.

Assigning-Footprints

Adjacent to the simulator button there is an assigning footprints button. Once you click that button, you will see three list. The one on the left is the one with all the footprint libraries, whereas the one on the right shows all the footprints in the selected library. The list in the center is the list with all the components from the schematic whose footprints need to be assigned. To assign a footprint, select the part from the middle list, then the footprint from the list on the right, then hit ok.

Note: Not all the footprints you assign will have vias in them. Many of them could be surface mount components allowing you to only connect them on the top layer.

PCB Editor

Choosing the Number of Layers

To choose the number of layers on your schematic, you should go to File -> Board Setup. From there, navigate to Physical Stackup and at the top there should be an option to select the number of copper layers that you want in your PCB. Meanwhile, in Board Editor Layers you can decide which layers you want to be signals, which you want to be power planes, as well as their names. I suggest taking a look at PCB Intro and Tips for more information about layers.

General Tools

1. For every PCB, an edge must be added. This can be done easily by drawing a rectangle around the PCB on the Edge.Cuts layer. It can be measured on a different layer using the ruler function on the right side of the screen

2. The Layers are visible on the right side, as a general rule only touch the copper layers (with the suffix .cu).

3. For layers that are for power/ground, you need to use the add filled zone on the right side of the screen after selecting the layer in question. From there, you will be prompted to select the name of the net you are assigning to that filled zone. After selecting it, you will need to outline the area you want filled. To see the filled areas, hit draw filled zones on the left (above draw zone outlines) and hit b.

4. To add additional components, just hit place at the top of the screen and navigate to the desired footprint. Note that this method is incompatible with the schematic to PCB method that I am suggesting here.

Updating PCB from Schematic

To automatically add parts from the schematic and/or refresh changed connections from the schematic you can click "Update PCB from schematic" at the top of the screen, adjacent to 3D viewer. It should have you automatically try to place unplaced parts from the schematic onto the PCB in a block. You can then move them manually elsewhere by right clicking them and selecting move. Meanwhile, the green lines indicate that those two nodes should be directly connected. When done like this, you cannot directly connect any two nodes that lack the green lines between them, which is great for reducing error.

Running DRC

Design Rule Checker (DRC) is a checking tool that helps reduce errors when designing PCBs. Under inspect at the top, select Design Rule Checker and then run DRC. It should provide you with a list of errors and warnings that you should attempt to correct (ideally).

Trace Width

Try to have the width of the traces correspond to the maximum current that goes through them according to the table below.

Current Maximum (A)	Width (mm)
1 A	0.25
2 A	0.76
3 A	1.27
4 A	2.03
5 A	2.79
6 A	3.81
7 A	4.57
8 A	5.59
9 A	6.60
10 A	7.62