5. Electronics production

This week I will:

  • Characterize the specifications of your PCB production process (group project)
  • Make an in-circuit programmer by milling the PCB, then optionally, trying other processes (individual project)

Research

  • Went through all of the electronic parts inventory to review what was available.

Results

  • Description: Complete assignments and produce outcomes of Week 5 Electronics Production.

  • Requirements: Show how I made and programmed the board; explained any problems and how I fixed them; include a ‘hero shot’ of my board

  • Planning: Setup the Roland SRM-20 mill for board production.

  • Materials: Using current laptop, internet connection, and Roland SRM-20 mill. Used MDF and synthetic wood to make a sacrificial platform. Fume extractor. Solder station and supplies. Microcontroller: 1x ATTiny 44 microcontroller; Discrete devices: 1x Crystal 20MHz; 2x Resistor 100 ohm; 1x 499Ω resistors; 1x Resistor 1K ohm; 1x Resistor 10K; 2x 3.3v zener diodes; 1x red LED; 1x green LED; 1x Capacitor 1uF; 2x Capacitor 10 pF 1x 2x3 pin header; 1x USB connector; one usb mini cable

  • Problems: I made 2 test boards successfully, but crashed 2 endmills in the learning process; my feed rate was set at 4 mm/sec. After several runs, the sacrificial board was getting worn and caused multiple bad parts.

  • Corrections: Slowed the feed rate to 3 mm/sec and never crashed another endmill. I moved the FR1 to the other side of the sacrificial board and the parts worked great.

  • Workflow: I used the mods after watching the tutorial videos and reading the 5.1 MODS tutorial. At first it was confusing, but practice makes perfect. Mods makes it so easy. Thank you, Neil!

  • Success: I made 2 test traces and cleaned them. I made multiple boards, but the last one was a keeper.

  • Learning: I have used a large mill, but had a lot of help. This was the first time I made parts completely solo; it was a great learning experience.

  • Using Roland SRM-20 mill is so much easier now. I look forward to making more boards.

  • Fabbed 2 USBTiny boards using Bryan’s page

  • Programmed first board without any problems

  • Programmed the second board after debugging by reflowing solder