PCB design without schematic

Hi, new on Kicad, how to make just PCB, without a schematic?

To have Zone filling working, you would at least need to write a Netlist for the areas you want Zones, e.g. “GND”

Other than that, turn off the drc with the red bug button on the top of the left side toolbar, and you should be able to throw down footprints and traces however you please.

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Normally, you draw the SCH, and export the NETLIST into to pcbnew, because that gives a good BOM base, and it gives a visual means to check.

That said, sometimes you may want a simple adaptor or motherboard.
Or, maybe you generate the whole design as scripts ?

In those cases, no-sch flows are possible :

Take a look at

and for simple place-footprints and add-connections approach, there is :

This is also useful where you want to pin-swap extensively, to make layout tighter, and not bother the SCH creator every time.
So you can use WireIT to shuffle many times, and then do a single pass update from the change list back to the SCH.

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I doubt the BOM is the most important part here. If i would have a guess then this price goes to the DRC which simply can not work without a netlist.

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Well, yes, DRC is important, but WireIT allows the netlist to be directly entered in the PCB layout.
It applies the default DRC settings to each named net, as they are added.

So, you can have DRC without SCH, but it is not so easy to get a full BOM from PCB side alone.
For some designs, that detail may not be important.

Really? Fabrication Outputs->BOM File… is pretty easy!

Yes, and for some that level of info may be enough.
Notice I said full BOM, and the BOM file here has only Ref;Footprint;Value info - pcbnew does not yet have full attribute fields, allowing in house part number and supplier part numbers and build variants. (etc)

It can be done, but is very rarely the best thing to do.
For very simple pcbs, creating a schematic first is not going to take longer and for cloning an existing board, an attempt at creating a schematic can help detect silly mistakes in the cloning


How do I make that Netlist?
I’m not using a schematic for my board and need the GND zone.

Just why are you so determined not to have a schematic? If you are getting the board made commercially, they want a valid netlist for electrical test

Board already made in CAD…just need to convert it to gerber files

What program did you originally use to make the board?

It was made in AutoCAD.
Just 25 LED and some header pins…not an advanced circuit. But the LED placement and the board-shape is special and has to be precise in relation to the rest of the design in the AutoCAD 3D drawing.

How are you expecting a netlist to help you create Gerber files?

Your current methodology for creating such a simple PCB is probably about as backwards as it could possibly be. And probably far more costly in terms of both time and effort than necessary.

You can import the board outline into KiCad and there are several ways to achieve precise placement of components in KiCad.

At the time of writing this it is 4:24pm in Denmark, you could restart this board from scratch in KiCad with an imported board outline and precise placement of 25 LEDs and have Gerbers by the time you went to bed tonight.

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Wel, it also take time to learn the schematic editor.
But board is made, GND connected manually, gerber files created and sent to china. I’ll get my 25 board in 10 days…excited to see the result :slight_smile:

How did you convert the AutoCAD to gerbers?

You can say I didn’t “convert” it. It seems there are no easy way of doing it, did search for it, you have to create the board in KiCad or similar tool.
1: I Imported the DXF file into Pcbnet (the board cut and small circles for every pin-hole)
2: Placed footprint of hole-pad on top of every circles (pin-holes)
3: Draw copper routes
4: Filled the board with copper and connected GND pads the filled copper with normal routes. 20 seconds…but doing the net way would have been fun - it’s a cool feature, but it would probably not be faster. And as you know I never manager to find out how.
6: Plotted to gerber files.

This way the board-shape and pin-holes are exactly as in my model in AutoCAD which is important.

It’s a nice tool, and has been fun to learn. Look forward to do it again :slight_smile:

AutoCAD Mechanical can export STEP files, which KiCad V5 can handle.

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