Homebrew PCBs

I have operated a plating pcb line in the past. The people there just 
buy a box of chemicals from a supplier and made the boards. The chemical 
supplier just ripped the manufacturers name from the chemical label and 
placed their own name. This chemical sets are available from many places 
(locally cost 400eur) and are easy to operate, the machine is just some 
plastic tanks with 2 of them heated, one with air pump and a 3-6V 40A 
psu, and a simple agitation moving the board holder from left to right 
and back again.

I never read what was on Markus Zingg's page or others but the chemical 
set seems easy to understand and from a lot of what i am been reading it 
seems easy to make all the chemicals from any local store. From car 
anti-freezer, ammonium, caustic soda, fine table salt, hydrochloric 
acid, tin solder wire, wine pH neutraliser, sulphuric acid, copper parts 
and a fertilizer bag (just the plastic bag clean for filter). I think it 
can be done but still didn't test.

It has a resin desmear bath made with resin etch and solvent to etch fr4 
resin inside the hole in a two components complex of anti-freezer, a 
bath to kill the remaining of the first based on acid salt, a activation 
bath made with tin colloidal, a ph neutraliser and the normal sulphuric 
acid copper plating with phosphorizated copper and anode bags. From what 
i understand of course.
The secret is making the holes electrical conductive before copper plating.
Another thing is the copper anode bags, they act as filters. If not used 
the copper is plated in big chunks and deposits on tank, eating the 
copper anode in less than 50% efficiency.

I will make some tests and give them here, but from
http://nr.stpi.org.tw/ejournal/proceedingA/v23n3/365-368.pdf
You can read was used in the past tin lead colloidal as activation bath, 
so my idea is put pieces of tin/lead solder wire in hydrochloric acid 
let the solder dissolve in bath add water to make 1% acid solution and 
place the drilled and clean board there for 5min. Then try to plate in 
the sulfuric acid copper bath at 30mA per square cm by half hour and see 
if the copper plates inside the holes.

Simao





Juan,

How to use it greatly depends on the chemistry used. The chemistry even
defines howmany tanks you need, wether they are heated, the processing
parameters etc. etc. My best advice to you is to first organize a
chemistry, cause it's supplier will be able to tell you the processing
requierements. Then build your station along them.

HTH

Markus

Juan EA7FNJ schrieb:
 >
 > Hi guys!
 >
 > Ok, great machine! but, I can see how to make one but, where is the
 > manual 'how to use it'?
 >
 > xD
 >
 > --- In Homebrew_PCBs@yahoogroups.com
 > <mailto:Homebrew_

PCBs%40yahoogroups.com>, "Steve" <alienrelics@...> wrote:
 > >
 > > Have you checked the Links under "Plated Through Holes" yet? Not many
 > > links there, but it is something. Markus Zingg's page on through hole
 > > plating has been down for a while, but I just found where someone
 > > mirrored it and put that link in place of the missing site.
 > >
 > > http://tech.groups.yahoo.com/group/Homebrew_PCBs/links
 > <http://tech.groups.yahoo.com/group/Homebrew_PCBs/links>
 > >
 > > If you find any other links on through-hole plating, please place them
 > > there.
 > >
 > > Steve Greenfield