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Subject: Re: [Homebrew_PCBs] Sharpie compatibility

From: "Jeremy Taylor" <jt@...>
Date: 2004-03-10

Lets put it this way, I'm in over $2K US. Digital titration, magnetic
stirring, 20 different indicator and reagent solutions, but this for more
than just etch, I now have Alkaline copper, acid copper, electro~less acid
nickel, and bright acid tin plating systems.
I have to use Lots of sulfuric acid, sodium carbonate, sodium hydroxide,
HCL, copper sulfate, h202, 4 different organic stabilizers, etc...

The recipe for Peroxy Sulfuric, along with COMPLETE instructions is at
www.thinktink.com
I don't think you need the FT2- stabilizer if you just plan to mask the
copper and etch, the stabilizer keeps it from etching other metals besides
copper.(copper/nickel/tin for LONG term corrosion resistance on boards I'll
be selling in kits, or just copper/ tin for things I'll be assembling myself
shortly after etching ) FYI tin directly on copper can become
non~solder~able in short amount of time, It starts immediately and works
it's way to the surface. I've heard in perfect storage conditions you can
get 3 years of solder-ability, but once it's soldered, it' stays conductive.
The nickel acts like a barrier to keep the copper and tin from direct
contact. If you don't mind lots of lead around your house, you can plate
60/40 solderplate with the same setup (chemicals and all) as the tin plate.
If you are at all interested in DIY plating (for thru holes, or tin)
www.thinktink.com and www.caswellplating.com are excellent sources of
information.

I'm not doing prototypes or ones and twos, I'm doing in house production
runs of my own products. Which I think is significantly different than the
standard DIY PCB mantra.
I still feel that ∗well ventilated CUCl2 is the best solution for DIY
prototypes

Also a note - I found a better - cheaper source for H202, 27% 1 us Gallon,
3.3err someodd liters. for $13.00, From Pool and hot tub supply store
"Lighthouse pools and spas" , It's commonly called Shock in that industry,
and every moderate town probably has a pool /hot tub shop - It's cheaper
that the wood bleach by volume, and works just as well.

JT

----- Original Message -----
From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, March 10, 2004 1:39 PM
Subject: Re: [Homebrew_PCBs] Sharpie compatibility, and other questions...


>
> > Personally I've switched to H-o5-S , I had to use Lab grade 50%
> > H202which I
> > purchased a 4L bottle from Post-apple scientific co.
> > http://www.postapplescientific.com/ I drove to PA to pick it up ,
cause
> > Freight shipping for 1 4L bottle was $100, the juice itself much
> > cheaper. I
> > switched to acid tin plated etch resist. And Peroxy Sulfuric wont eat
> > thru
> > the tin, like CUCl2 will. + I can reclaim the etched copper and reuse it
> > in
> > my copper plating bath for thru holes, and no more chlorine smell.
> >
> > JT.
> >
>
> How is the process, what do you need to measure to keep things going?
> If there are any advantages (like no clorine) i may switch over when the
> HCl
> bottle is finally empty (but that could take another few years at that
> rate...)
>
> ST
>
>
> Be sure to visit the group home and check for new Bookmarks and files:
> http://groups.yahoo.com/group/Homebrew_PCBs
> Yahoo! Groups Links
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