4 ms·

Or just scrub the board with a bit of ferric chloride and a sponge. I've also seen a modified version of this method that might be better for larger boards that

• squarefoot 2y ago
  > Or just scrub the board with a bit of ferric chloride and a sponge. If you use ink pen and transfer pads like I did decades ago, the sponge would almost certainly wipe the pads off. The best way that I'm aware of to ensure the copper is being consistently covered by the solution is to use an air pump to produce bubbles under it. Those used in aquariums are quite cheap and durable.
  • deleted 2y ago
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• wrs 2y ago
  Yes! The sponge technique takes a little practice to get consistent results, but it works well (at least for small boards), and lets you use microscopic amounts of etchant, which is good for cleanup. I find it’s especially good when trying to do relatively small traces, because you get such fine control over the process. (I have to say though, nowadays I’d usually rather wait six days for JLCPCB to do it for me.)