Scratch Milling PCB’s at Home

Making Circuit Boards
KiCad and Scratch Milling
Through Hole SMDs
Scratch Milling Jigs
FlatCam and bCNC for Scratch Milling
Scratch-and-Peel Milling
Scratch Milling on the Nomad 883
Etching and Tinning
Soldering and Board Assembly
Programming DIY PCB’s

It’s amazing how good online printed circuit boards (PCB) services have become, but the one thing that still will kill the prototyping buzz is long turnaround times. Prototyping works best with many quick iterations, and this is where DIY boards can really help. I’ve been experimenting a lot trying to find the fastest, easiest and most consistent process for idea-to-blinking-board. I’ve tried photo-lithography, toner transfer and milling, as well as various etching, soldering and assembly processes. While it’s all very much a work in progress, I’ve written out what works best for me so far.

I have a Nomad 338 milling machine, which is fantastic, but I don’t have a laser cutter yet. Therefore this process relies mostly on milling. It’s definitely a plus to do everything on the same machine, but I will probably adjust things somewhat once the laser cutter arrives.

The TL’DR is:

  • KiCad
  • FlatCam
  • Autolevel in bCNC
  • Cover the PCB in Magnum Sharpie ink and scratch the patterns with a scriber (using the milling machine, but not spinning the bit)
  • Scratch the bottom layer
  • Etch with Muratic acid and Hydrogen Peroxide (1:2)
  • Test connectivity
  • Clean with Acetone and alcohol
  • Reattach the board and drill on the back layer
  • Soak in liquid tin
  • Solder components
  • Test and program

I am also experimenting with using SMD’s as through hole components making them much easier to place and solder. I think it works really well, but YMMV!

I will be updating these pages as I go, but they should always be visible from the drop down menu of this blog. If you have ideas or tips I’d love to hear them, thanks!

Begin: Making Circuit Boards