{"id":145,"date":"2019-12-30T02:06:06","date_gmt":"2019-12-30T02:06:06","guid":{"rendered":"http:\/\/labparvum.dynet.com\/?p=145"},"modified":"2025-05-28T10:11:48","modified_gmt":"2025-05-28T10:11:48","slug":"self-etched-pcbs","status":"publish","type":"post","link":"https:\/\/labparvum.com\/index.php\/2019\/12\/30\/self-etched-pcbs\/","title":{"rendered":"Self etched pcb’s"},"content":{"rendered":"\n

I had to create a simple 9V power supply for an electronics class in college.
But because I found this a bit too simple and boring I decided to make it more interesting by making my own PCB’s for it instead of ordering one from JLC or making it on a perfboard like the other students did.<\/p>\n\n\n\n

The first step is to clean a blank PCB to remove any oils or dirt that might be on it. Then apply a few even layers of black paint with a spray can.
Let it dry for an hour or 2 at least and then mount it on the laser engraver.
it did this with 2 neyodium magnets so it wouldn’t move around. some tape on the edges or double-sided tape works too.<\/p>\n\n\n\n

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First attempt looks good at first sight but when inspected with a microscope it didn’t look to great.<\/p>\n\n\n\n

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Adjusting the laser head and slowing the movement speed the improved the quality a lot with the second attempt<\/p>\n\n\n\n

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When looking closely at the smallest features the staircasing can still be seen.
But it’s more than small enough for even some tiny smd parts.<\/p>\n\n\n\n

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Letting the PCB soak in aced for +-10 minutes removed all of the exposed copper.<\/p>\n\n\n\n

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After removing the paint with acetone a nice PCB is left.
I tried to drill small holes but my drill heads kept breaking, so I had to use a 1mm drill that was slightly too large for the smaller pcb tracks.<\/p>\n\n\n\n

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Acid<\/h2>\n\n\n\n

I used a self made acid solution to dissolve the copper from the PCB.
The solution used 2\/3 Hydrochloric acid(30%) , 1\/3 hydrogen peroxide(7%).<\/p>\n\n\n\n

The key chemical reaction is: <\/p>\n\n\n\n

Cu\u00a0(solid)+2HCl\u00a0(aqueous)+H2\u200bO2\u200b(aqueous)\u2192CuCl2\u200b(aqueous)+2H2\u200bO(liquid)<\/p>\n\n\n\n