Homebrew PCBs

spacedcowboy@... wrote:


> The basic problem here is a lack of knowledge on my part. In their
> initial email, they claimed there are 3 things I'll need:
> 
> - copper-bath. My guess on this was CuSO4, but what molar
> concentrate ? I don't know.
> - black hole agent. I have no idea what this is.
> - mild etching agent. Again, I have no idea. Dilute HCl ? 
> 
> I've asked for more details, but am currently waiting for them to wake
> up :) I think it's about 8AM over there as I type this...
> 

So such machine is built for black hole chemistry? It requires double
pass and micro etch (sulfuric acid with hidrogen peroxide or persulfates
to remove it from the surface). Personally for homebrew/small runs i
only care about palladium based ones. See it here:

http://books.google.pt/books?id=g9Q8RekeKaAC&pg=SA30-PA1&lpg=SA30-PA1
(not every page still available)
http://nr.stpi.org.tw/ejournal/proceedingA/v23n3/365-368.pdf


If you find this complicate, the copper bath itself is so much
difficult. And you still need 4 types of additives for it.


> ... and I've read that typically the shelf-life of these things isn't
> great...

The conductive polymer chemistries have volatile compounds. Palladium
based will last something like 2-5 years, but is better to use it at
least once a month. Black hole or graphite ones don't really know...

Sim�o