Current method to make odd shaped PCB? - Page 1
Forum section: electronics / general

author: eugenenine
author_rank: Frequent Contributor
timestamp: May 05, 2017, 01:05:33 am
content: My Googleing is showing up old hits from 2013, what is a current method to make a odd shaped PCB? Can I draw it in openscad or something first?

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 05, 2017, 01:11:07 am
content: What does "odd" mean? Do you mean making a board yourself?Or do you mean creating a PCB layout -> Gerber files and sending them off to be made?Since we have seen board shapes in nearly every imaginable shape, you question seems odd.

author: eugenenine
author_rank: Frequent Contributor
timestamp: May 05, 2017, 01:13:43 am
content: Yea, I want to upload to someplace to make it. How do I draw an odd shape outline to then add my traces to.

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 05, 2017, 01:30:01 am
content: Quote from: eugenenine on May 05, 2017, 01:13:43 amYou lay out a PC board using one of dozens of different PCB layout tools, some free, some inexpensive, some expensive, and some by subscription. There are literally hundreds of discussions in the General PCB/EDA/CAD Discussions section of this website.Laying out a PCB for an "odd" shape is no different than laying out a PCB for a conventional rectangle or round (or whatever) shape. There is typically one "layer" which defines the outside "cut" of the board shape. On that layer, you can put a rectangle, a round or oval shape, or something in the shape of a chicken-head for all they care. As long as you stay within the "design rules" of the fabrication factory, they don't care what shape it is. You will typically be charged as if it were a rectangle inside which your undefined "odd" shape fits.

author: stryker
author_rank: Regular Contributor
timestamp: May 05, 2017, 01:49:26 am
content: Quote from: eugenenine on May 05, 2017, 01:13:43 amMy workflow in KiCad is to convert the bitmap of the shape to a footprint (a logo essentially), place it in Eeschema, then trace the shape out on the Edge Cut layer in straight sections and curves. Once exported it generally will take a few iterations of checking the gerber viewer as if the edge cut boundary isn't perfectly enclosed (ends of adjacent lines and curved sections 100% in the same location) the shape won't work. When done remove the logo footprint.If you then place your traces they won't go outside the board outline shape. The Design Rule Check will make sure nothing strays too near the edge etc as it would for a rectangular PCB. Using this method I nearly always at least radius the corners on my PCBs and will typically make them shaped to suit the enclosure, or to make space for a battery etc.It's simple, but tedious. Sometimes theraputic...

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 05, 2017, 02:56:44 am
content: Quote from: eugenenine on May 05, 2017, 01:13:43 amYes you can do that.Draw your odd shape on the keep out layer. That is your board shape, ignore the rectangular background that is just a working area. To make the odd shape you can do as many curves and straight lines as you want.Then move back to top and bottom layers to do the copper traces.

author: apurvdate
author_rank: Contributor
timestamp: May 05, 2017, 05:33:17 am
content: simplest thing isopen any cad tool -> draw shape & export dxf -> import that dxf on edge cuts layer

author: Neilm
author_rank: Super Contributor
timestamp: May 05, 2017, 05:02:20 pm
content: Be aware that some machinery will not handle odd shaped PCBs - I am think particually of SMD pick and place. If I have an odd shape, I tend to use a square PCB and route out the board shape in that with a few breakouts to remove the PCB after it has been populated.

author: donotdespisethesnake
author_rank: Super Contributor
timestamp: May 05, 2017, 07:24:56 pm
content: Quote from: eugenenine on May 05, 2017, 01:05:33 amCurrent methods:1. Draw onto the Edge Cuts layer in kiCad2. Create a DXF in a CAD package and import it. I never thought of using OpenSCAD, but I just tried it and it works! There are some limitations to the DXF import, I think beziers are not supported.3. Generate a PCB file using external code, Python, C# whatever. You can create a complete pcb to use as a template, or copy and paste graphics into an existing file with a text editor if you like.The method of creating a footprint with graphics on the Edge Cuts layer is somewhat deprecated, so I would avoid that.Whether you can manufacture the board or not I leave up to you, if you etch your own do it how you like, if you send to a fab house get familiar with what they can do and what "extras" they charge for, and how they want outlines/slots etc specified.