Homebrew PCBs

--- In Homebrew_PCBs@y..., "j_hallows" <j_hallows@h...> wrote:
> --- In Homebrew_PCBs@y..., JanRwl@A... wrote:
> > each!  Seems plating-through should be within the realm of us ol' 
> > home-brewers who can make a double-sided board, if we just knew 
the 
> steps, 
> > and where to get the chemistry to plate the holes before etching.
> > 
> 
> Could not agree more. I know the thoery but the practice it's a 
whole 
> different ball park.
> 
> 
> > You DO know, doncha, that the PTH is done FIRST, then "SOLDER-
> plating" of the 
> > desired pattern (including through the holes!), and etch LAST, 
> > with chemistry that will etch copper, but NOT "solder".
> > 
> 
> Took me sometime to figure this one out. But it's not solder but 
> tinned. And the process is called pattern plating.
> 
> As a homebrewer it is too expensive for me to send boards out to 
> make. If I could only find out a simple way to make plated thru 
holes 
> at home without killing myself. And eyelets and baluns are too time 
> consuming.


Hi there, 

I just discovered this yahoo groups forum on making PCBs at 
home. Its good to see people out there making boards 
themselves. When I saw the post on trying to do PTH at home I 
though this could be something I might able to answer.

Making plated boards involved many more processes than a 
simple 'print and etch' method. I'm sure you know that first the 
holes must be made conductive in order to electroplate with 
copper. This is one of the major challenges, and the industry may 
use one of several techniques. I will not go into the details 
because much of this information in already explained on the 
web. An excellent information source is;

http://www.epa.gov/dfe/pubs/pwb/tech_rep/usecluster/pr_toc.htm

PTHs are possible to do at home but you should be aware that it 
involves many chemical stages. Although these chemicals are not 
necessary highly toxic they can be a difficult process to control 
and get working properly. So unless you find chemistry fun and 
don't mind getting your hands wet then I its a complete waste of 
time and money trying to implement a PTH workshop at home. I 
have setup the necessary plating and etching tanks to make a tin 
finish pattern plated board and had taken me almost two years. 
The holes are made conductive using a processes similar to 
MacDermid's BLACKHOLE processes where by a conductive carbon 
black layer deposited inside the holes prior to electroplating. If 
you have any questions then feel free to ask.

Adam