Musings of a Fondue

Tag: Pcb-design

Simple PCB

Just a simple “led and resistor” circuit to test the end-to-end process of making a circuit board.

Unfortunately, I forgot to flip the image before printing, and only noticed after the board was already etched.

pcb

lights on

DIY PCB Etching

I wanted to learn how to etch PCBs at home. (Read as too cheap to pay someone else to do it). I was pleasantly surprised by the results.

- Board prep -

I lightly sanded the copper layer with 800 grit sandpaper (it was the finest grit I had on hand) to remove the oxide layer. I then rinsed it with water and wiped with isopropyl alcohol.

- Transfer -

I used the “printer toner and iron” method to transfer the design onto the copper. (Why - cheap). Steps:

  1. Tape magazine paper onto regular paper
  2. Print your design onto said magazine paper using a laser printer
    • make sure to mirror (vertical flip) the design before printing. I forgot to do this.
    • when printing, select the highest resolution (dpi) your printer offers
  3. Place the paper on top of the copper board
  4. Iron it
    • this transfers the toner to the copper board
    • I had my iron set to the highest temperature but ymmv

When it seemed like the toner had transfered, I soaked the board in water then gently peeled off the magazine. See this video for an example.

The design:

The toner transfer:
toner transfer

I then touched up spots missed by the transfer using a permanent marker:
sharpie touchup

Eagle PCB Layout

I was going through a SparkFun tutorial on reading schematics, when I decided to use it as an opportunity to learn a thing or two about PCB layout.

My candidate circuit was that of the FT231x breakout board mentioned in the article. SparkFun releases all of its products as Open Source Hardware, so the relevant schematics were provided on the product page.