put today's tiny glass PCB and put it under the microscope to get some close up shots! it's really cool to see just how thick that 0.1mm copper is! there are still tons of flaws that become very apparently once you zoom in, some small bridges and some thin spots and breaks in in some traces. once you get up close it all looks very… organic.
here's some closeups of the small bridges. the very thin ones tend to be easier to see from the back. good thing glass is see through!
I'm still struggling to completely avoid these, but I think my track spacing might still be a little on the low side for this thick copper layer. maybe I also just need to etch for longer, but I'm worried about excessive under-etch…
luckily the small bridges are very easy to clean up with a scalpel.
there are also a bunch of other small defects, probably caused by small bubbles or other defects in the photoresist. luckily only one of them seems to have led to a broken trace which I'll have to fix later.
oh yeah, also, all the brown stains all over the PCB? don't just dump dry NaOH into the resist stripper bath when it's starting to run out. getting it onto the PCB will fuck up the copper surface…
last but not least, a test fit with one of the chips. it fits! Wheeeeee!
Kris\Slyka
Patrick Herd
F4GRX Sébastien