How to Make (almost) Anything 2023 | Week 6.1: Electronics Production

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Assignment: Group Project -- Characterize the design rules for your in-house PCB production process send a PCB out to a board house; Individual Project -- Make and test the development board that you designed to interact and communicate with an embedded microcontroller.

Individual assignment: Make and test the development board

Description: Utilizing the KiCad PCB design from week 5.1, I converted the output from KiCad into G-Code via the Mods platform. This G-Code file was then fed into the software communicating with the CNC PCB mill to produce the physical PCB.

Primary files:
  1. Electronics Design PCB schematic and design (KiCad)
Procedure:
  1. Taking the PCB design from week 5.1, export the design as an SVG file
  2. Convert the F.Cu and EdgeCuts SVG files into PNG files using Adobe Illustrator, then edit the EdgeCut PNG by adding a white rectangle over the inside of the edge cut design
  3. Using the Mods platform, right click and select "programs" > "open program" > "mill 2D PCB"
  4. Upload the F.Cu PNG file to the Mods platform, and select "mill trace (1/64)" under "set PCB defaults" and select "calculate" under "mill raster 2D"
  5. Validate the G-Code path appears as expected, and export the G-Code output
  6. Upload the EdgeCuts PNG file to the Mods platform, and select "mill outline (1/32)" under "set PCB defaults" and validate the desired tabs under "image tabs" prior to selecting "calculate" under "mill raster 2D" (note: I experienced a bug on the Mods platform where the tabs were not properly attached to the edge cut outline, but Mods would crash when only one tab was selected; given this, both tabs were kept although only one tab provides structural support to the edge cut)
  7. Validate the G-Code path appears as expected, and export the G-Code output
  8. Import the F.Cu G-Code file to the desktop attached to the CNC milling machine
  9. Prepare the CNC by clamping down a sacrificial sheet of copper (bottom) and the milling sheet of copper (top), then secure the 1/64 end mill using the blue guide to determine proper end mill depth
  10. Move bit to x=0, y=0 and then ensure the ground lead is attached to the top of the probe before zeroing the z plane
  11. After the z dimension has been probed and raised, remove the ground lead from the probe and insert the plasstic cover over the end mill then turn on the vacuum
  12. Press play on your mill trace
  13. Upon completion of the mill trace, turn off vacuum, remove plastic cover, and exchange the end mill for the 1/32
  14. Upload the EdgeCuts G-Code file to the desktop attached to the CNC milling machine
  15. Repeat steps 10-12 with the 1/32 end mill for the mill outline
  16. Upon completion of the mill outline, turn off vacuum, remove plastic cover, and snap PCB from the copper sheet
  17. Inspect the PCB to ensure the trace was clean and as expected; If complications occurred, adjust design as needed and repeat PCB production
  18. Solder the specified components onto the PCB
  19. Inspect the soldered component to ensure there are no shorts within the circuit
  20. Validate the circuit by powering the Xiao RP2040 and ensure the LED turns on as anticipated
Key learnings:
  1. Inspecting your PCB throughout the process can save time debugging at the end -- It can be very helpful to undergo inspection / sense checks with your PCB at each major checkpoint throughout the design and production process in the hopes of catching an errors early on before it is produces and covered by components / solder that may hide small errors within the PCB


KiCad development board design
KiCad developement board design (Week 5.1)



PCB trace footprint
PCB trace footprint



Mods conversion of PCB PNG to G-Code
Mods conversion of PCB PNG to G-Code



CNC PCB milling in progress
CNC PCB milling in progress



PCB production output
PCB production output: LED lights up when button is pressed