Esigning Your Own PCB

I swore that this project wouldn't happen... not because of technical difficulties but because it seemed far from possible or likely to happen, I had thought about electroplating with conductive copper paint and the like until I discovered copper tape for resurfacing musical instruments such as guitars and basses.Follow the circuit's development below, along with the materials and software used to create this PCB—which, for the first time in my life, wasn't made in China (Chinese folks... you guys are amazing!!!).

As for the strictly necessary materials, we have:

1. An FDM-type printer (in my case, a Creality Ender 3 Pro).
2. PLA filament (although it does not withstand temperatures above 210°C without total deformation, and can deform or lose its shape at temperatures between 60°C and 80°C; however, in my experiments, the low current of the overall circuit meant I did not encounter any issues).
3. Adhesive copper tape—the kind used for shielding musical instruments, such as in guitar and bass circuitry.

As for the software used:

1. Initial trace modeling and layout were done in EasyEDA.
2. Due to limited familiarity with EasyEDA and a learning curve that requires some patience... a screenshot of the circuit was taken and imported into Fusion360 (Autodesk is the absolute best!!!!).
3. In Fusion360, the design was extruded, and the traces were drawn one by one (I’ll describe the process in the next steps!!!).
4. An STL file was generated once the design was finished.
5. The 3D-modeled board was sliced ​​in PrusaSlicer and was basically ready for printing!!!

As I mentioned earlier... I tried using EasyEDA but didn't have the patience for its learning curve. What I did instead was search the platform's extensive public libraries for the pinout patterns for the ESP32-C3 SuperMini, ESP32, and any standard pinouts for sensors and similar components. A quick tip: any two holes can accommodate a resistor, diode, or similar part...

So... after designing the circuit, I took a screenshot and imported it as a background image into Fusion360. There, I redrew the traces and discovered something fascinating: the pattern of the pads...

1. The circles are spaced 2.54 mm apart, center-to-center.

1. The circles have an outer diameter of 2 mm.

1. To accommodate FDM-printed pins—meaning, for the circuit pin to fit into the board—the inner diameter of the 2 mm circle needs to be at least 1.7 mm.

Once you finish the design—completing the sketch and saving the project under your preferred name—export the file as an STL; this ensures all the dimensions remain preserved in the file you created!

1. Note: The tracks were about 1.5mm wide, and I encountered no issues during the design phase or with post-processing.

After saving the file to your preferred folder, open your slicing software (I use PrusaSlicer) and set the hotend nozzle parameters to 0.20mm (nozzle 0.4); a 5% infill works great! In my case, the board thickness was 2mm—I found that a bit too thick; 1mm would probably be a good size!

When you finally see the finished result of all that hard work, you might even shed a tear, man!

After finishing the FDM 3D printing of the PCB base in PLA, it was time to place the sensors or microcontrollers on the board to check the spacing—which had been planned in EasyEDA and then Fusion360... and guess what? Everything fit perfectly, thank God!

Once the holes were tested and the pins were confirmed to pass through the board, it was time for the copper plating process!

To coat the PLA board with copper—making it solderable with tin so it can finally be called a true PCB—you need to cut a piece of copper foil large enough to fully cover the board. Then, gently rub it with a cloth until the traces are clearly defined and visible, just like in the photos

Using plenty of patience and a utility knife, cut the copper tape between the traces.

After cutting the traces, use the non-cutting edge of the knife (the back of the blade) to press down and secure the raised edges of the tape against the sides of the traces on your PCB prototype.

ATTENTION: The cleaner and more precise your cut between the traces, the greater your chances of success.

Success depends entirely on the quality of the cut between the traces and—of course—on verifying that there are no unintended connections (short circuits) between traces, using a multimeter set to continuity/beep mode (or diode mode, whichever you prefer).

Only solder your components to the board after verifying that there are no short circuits between the traces (especially at your circuit's power inputs)!!!

After securely mounting your electronic components, solder them in place; the soldering must be done quickly to avoid lifting the traces and, of course, to prevent deforming the board's channels.

Note: On the small board shown in the image, I applied a small amount of SLA-type 3D printer resin to improve shielding and protect the designed board.

God willing, by following these steps, you will successfully design the board of your dreams—trust the process!