Other options would have been to mill or have the boards fabbed overseas, but because of the rapidly approaching deadline (Format Festival) we chose etching.
We’ve never been keen on chemical etching, but the acid cupric chloride process involves the least waste.
Pix & Ryan’s setup included:
- Cereal storage containers
- A woefully inadequate aquarium air pump (which was quickly replaced by…)
- Industrial air compressor (which required…)
- Foam block and rubber band based airflow regulator
The process involves:
- Printing the circuit layout onto toner transfer paper
- Ironing the toner onto the blank PCB material
- Mixing up the hydrochloric acid & hydrogen peroxide solution
- Accidentally sacrifice the copper from several boards to make acid cupric chloride 🙂
- Regenerate the acid cupric chloride with copious quantities of bubbled oxygen
- Etch as many PCBs as you can until the solution is saturated with copper
- Clean the toner / etch resist off of the PCBs with acetone
- Regenerate the solution, wash, rinse, repeat!
And of course, some happy snaps: