Electronics Production

Overview

This week is my first time ever producing electronics, or a PCB. In this assignment, I tested the milling machine and found the design rules for in-house PCB production, you can find details about the test [here]. Then I used the findings to produce a PCB, which is the Quentorres created by Quentin Bolsée and redesigned by Adrián Torres.

This TikTok is a recap of the whole process of me producing the PCB. Details, files and all screenshots are found in this page. [The language of the video is Arabic but you can turn on auto translation.]

@santhewitch #pcb #electronics #bahrain ♬ original sound - null.

What is a PCB?

PCB stands for Printed Circuit Board. It is a way to connect electronic components together with conductive material for them to function. There are different types of PCBs, and different ways to produce them. A PCB can be single-sided PCB, double-sided PCB, or multi-layered PCB. Added to this, electronics components assembled in the PCB can be of different types, through-hole or surface-mount.

  • What we are producing in this assignment is single-sided, surface-mount PCB.

    • Prepare your Traces

    We are producing Quentorres Development Board, the design, schematics, and all of the steps to produce it are all documented here

  • Download the traces for the quentorres. You should have three png files:
  • Traces is the first thing we are starting with.
  • Drills is second.
  • Interior is the outline of the board, which is the last thing to make.

    • MODS Project CE

  • After downloading all the designs, now we have .png images for the paths. I am using modsproject.org to generate the tool path.

  • Right Click > Programs > Select the machine you are using, the one we have in house is Roland SRM-20 mill, and I am using it to mill 2D PCB.
  • Select the png file, make sure the size is accurate and it will fit in the copper plate.
  • Start with the traces first, and after we are done with them, we will do the outline cutting.

  • Navigate to v-bit calculator, as I am using this v-bit for milling.

      • Change the following according to the bit:

    • angle: 30
    • cut width: 0.164 mm
    • cut depth: 0.12 mm
  • Adjust the speed. I put it 2.5 mm/s so it is not so fast and not so slow.
  • We are starting from the corner of the sheet, so set the origins to X:0mm, y:0mm, z:0mm.
  • Turn output on so you can have the file downloaded to upload to the machine software.
  • After calculating, you should be able to view the path generated and check if there is anything that does not look right.

    • Setup your Machine

  • Stick the copper sheet with double sided tape. I placed it in the left corner of the machine.
  • Make sure the bit set in the machine is the one you filled the settings for in mods projects.

    • VPanel for SRM-20

  • Now that we have the file saved, and we checked the path and they look good, go to to VPanel for SRM-20.
  • Move [x/y] axis then set the [x/y] origin.
  • Move [z] axis carefully and get it as close as possible to the z-origin from the panel without hitting the sheet, bit needs to be set manually after that. .
  • Click on Cut > Delete files and load the file to cut [quentorres_traces].
  • Click on Output to start cutting, it took around 20 minutes to finish the traces.

    • Cutting the outline

  • After finishing the traces, it is time to cut the outline of the PCB.
  • Repeat the same steps above but we are not using v-bit, we changed it to 1/16" bit.

    • Obstacle

  • After the machine finished the traces, we cleaned it and it did not look so good, the tracks did not look clean.
  • I almost gave up and went to set another sheet for cutting. But after a little bit of sanding to the surface of the PCB, it looked way better. The pictures below are to compare it before and after sanding.
  • Keep in mind: Sanding does wonders.

    • Soldering Like a Pro

    PS: I burned some headers, I had to desolder them, then solder new ones, so definitely not a pro.

    Electronics Components List:

    SEEED STUDIO XIAO RP2040 x1
    RES 1K OHM 1% 1/4W 1206 x4
    RES 499 OHM 1% 1/4W 1206 x1
    LED CLEAR 1206 SMD x3
    TACTILE SWITCH SPST x1
    CONN HEADER SMD 10POS 1.27MM x1
    CONN HEADER SMD R/A 6POS 2.54MM x1

    Checking Conductivity

    Before actially powering the PCB to program it, and after soldering everything, it is good to check all things are connected the way they are supposed to be. For that, I used a multimeter, and tested the electronic components and their paths it it is connected or not. Also I had to check if they are connected to paths they are not supposed to be connected to, which will result in a short-circuit.

    Does the PCB Work Now?

    Spoiler Alert: It does!

    Programming

    After soldering, checking the conductivity in the tracks, it is time to program the PCB. For that I used Arduino IDE.

  • Start with the basic Blink Just to check the LED and the Xiao.
  • Then I wanted to test other components so I tried Button with LEDs.
  • Note: for now we know that the LEDs work, and the button. But we did not try the headers.