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Subject: Re: [Homebrew_PCBs] Re: 35% H2O2 and HCL - Ratio?

From: Slavko Kocjancic <eslavko@...>
Date: 2010-06-21

msilv3r pravi:
>
> Thanks Slavko. I just did it and it certainly etched the copper well. A little too well. I thought the transfer looked great. However the etch took off the copper and then some. You can see pics of it here:
>
>
> This is the transfer on the PCB. Looks good in my opinion: http://www.msilverman.me/wp-content/uploads/2010/06/DSC_0138.jpg
>
> This is the finished etch. Looks horrible:
> http://www.msilverman.me/wp-content/uploads/2010/06/DSC_0142.jpg
>
> I almost feel like I made the traces too small.. I made them .016 inches. Any recommendations?
>
Try with just of half of H2O2 (it's here to act as the accelerator) and
when you see copper etched immideatly remove board out of solution and
rinse it under watter. Try to have etching time aprox 3 to 5 minutes. If
goes to fast the board can be heated to much but longer time isnt
problematic (I just don't want to wait)

16 mils traces should be just fine. But the question is do you need
that. When designing PCB use the largest width you can. When there isn't
enought space then use thiner one. So if you have space for 50mils
traces (this exampe have much more space as I see) use it.!
I start all my design with 50mils signal traces and use thiner up to 8
mils if I needed. For cooper pour if I needed that I use at least 16
mils isolation.