I do DIY PCB with the following steps:
1) Apply the circuit diagram on a presensitized PCB via an UV lamp 2) place it into positive developer (NaOH) 3) clean it via water 4) place it into an etching solution (sodium persulfate) 5) clean it via water 6) dry it then clean it via Acetone (to solder easier) 7) drill & solder
I produced several PCBs and noticed that the copper parts are getting corroded in a month or so.
What chemical/material do I need to apply in order to prevent them to get corroded? I guess that procedure should be done after step 6, right?