There are a couple of ways to create your own PCB (Printed Circuit Board) that I am aware of. Here I would like to present a high-level overview of some possible approaches
It all starts with your layout/design.
I am using Autodesk EAGLE for this. BTW, free to use -with a size restriction on the board.
1.
After designing it in a CAD software, you can send it off to a PCB factory in China.
Advantages: Professional, mass production, can create more than two layers in the PCB
Disadvantages: Delivery times, need a perfect design.
2.
A second approach is to Etch the board yourself using chemicals
Advantages: cheap, but any fun?
Disadvantages:Time consuming, messy, trial and error, limited production
3.
A third approach is to use your own CNC machine to carve it.
Advantages: Really fun, rewarding, once you have it down, the machine is working for you.
Disadvantages: Trial and error, limited production
Since I now own a CNC, I wanted to give number 3 a go.
Here is my Schematics in Autodesk EAGLE
EAGLE can export Gerber files per out of the box. This is the standard filetype for sending files to professional PCB production.
As I am currently using Estlcam as a controller software, I need the output file to be G-Code. Luckily there is a PCB-Gcode ULP (User-Language-Program) created for EAGLE. This ULP (created in Processing BTW) exports your G-Code with your desired settings in regards to cutting depth, isolation size and layers and so on.
It’s possible to print 2 layers on the PCB, front and back side. However I havent tried this yet. You will need to run an automated touch-off any minor offsets created when moving the board gets written to the g-code and accounted for.
Estlcam has support for this!
Crucial points:
- Make sure your copper clad is well secured to the wasteboard. I am using doublesided tape on top of a 5mm piece of foam plate.
- You will need a probe to scan the surface area of the board. I am running a simple wire from ground to SCL pin on my Arduino CNC shield
- Use your milling software to run a surface scan of the PCB. The PCB is not straigh even though it looks like it!
- Use a 0,1mm tip 60degree V-bit or even pointier to achieve the wanted isolation. The deeper you go with a V-bit the bigger the isolation groove gets.
- Run spindle at around 20.000 RPM, go slow feedrate, about 200mm per cm
- Define 0.2mm cutting depth and one pass in PCB G-code setup.
- If you do a through-hole board, to cut the holes use 0,8mm straight drill bit. The g-code for drill holes is created separately, and is run seaparately.
