Homebrew PCBs

Interesting weekend of board building.  I had a number of boards to 
make with some rather fine traces (well, fine to me - .010 with .010 
spacing).  So, I decided to use the pulsar toner transfer paper rather 
than ink jet or magazine pages.  What a mistake that was!  I went 
through 5 sheets of pulsar paper and never got a good transfer.  I 
printed out the layout on my HP Glossy inkjet paper and had 8 good 
transfers in a row - double sided at that! I give up on the "good" 
paper and will stick with the cheap stuff - magazine pages and glossy 
ink jet paper when I have some.

I tried the Liquid Tin product this weekend. Made by MG Chemicals and 
can be purchased from Allied Electronics. It's a bit expensive, about 
$30.00 for a bottle - have no idea how many boards can be tinned with 
it. So far I have gotten 8 boards, that's all I know so far for life;-)

VERY easy to do.  Pour chemical in flat tray, put PCB in for 3 to 5 
minutes, take board out, rinse and your done.  Put the chemical back 
in it's bottle for the next use.  Much easier than the solder paste I 
was using and looks a bunch better too - thanks for that tip Robert!

Chris

On Mon, 21 Aug 2006 20:59:09 +0200, lcdpublishing  
<lcdpublishing@...> wrote:

>
> I tried the Liquid Tin product this weekend. Made by MG Chemicals and
> can be purchased from Allied Electronics. It's a bit expensive, about
> $30.00 for a bottle - have no idea how many boards can be tinned with
> it. So far I have gotten 8 boards, that's all I know so far for life;-)
> VERY easy to do.  Pour chemical in flat tray, put PCB in for 3 to 5
> minutes, take board out, rinse and your done.  Put the chemical back
> in it's bottle for the next use.  Much easier than the solder paste I
> was using and looks a bunch better too - thanks for that tip Robert!
> Chris


Just make sure you use the usual precautions, this probably contains  
thiurea which is not so healthy...

ST

It came with an MSDS, I read through it, but considered it to be 
about as safe as all the other crap in the shop - NOT!  Luckily it 
has a pretty nasty smell so doing it outside is your best bet, 
unless you like bad smells and getting sick ;-)

Now if the rest of my components show up sometime soon, I should be 
able to test all these boards out this week to see if any of them 
work.  I really rushed through the design and layout phase and 
didn't have my head in it at all so if they do actually work, I will 
be pleasantly surprised :-)

CHris



--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@...> wrote:
>
> On Mon, 21 Aug 2006 20:59:09 +0200, lcdpublishing  
> <lcdpublishing@...> wrote:
> 
> >
> > I tried the Liquid Tin product this weekend. Made by MG 
Chemicals and
> > can be purchased from Allied Electronics. It's a bit expensive, 
about
> > $30.00 for a bottle - have no idea how many boards can be tinned 
with
> > it. So far I have gotten 8 boards, that's all I know so far for 
life;-)
> > VERY easy to do.  Pour chemical in flat tray, put PCB in for 3 
to 5
> > minutes, take board out, rinse and your done.  Put the chemical 
back
> > in it's bottle for the next use.  Much easier than the solder 
paste I
> > was using and looks a bunch better too - thanks for that tip 
Robert!
> > Chris
> 
> 
> Just make sure you use the usual precautions, this probably 
contains  

> thiurea which is not so healthy...
> 
> ST
>

>Much easier than the solder paste I
>was using and looks a bunch better too - thanks for that tip Robert!

My experience with Liquid Tin boards is that the tin coating is ultra 
thin and it suffers from flux discoloration. The nice silvery finish 
is replaced by an ugly irreversible gray/brownish tarnish wherever the 
flux touches. Even Tinit boards are better in this respect. If you 
don't use extra flux (other than what's in the solder) then you may 
not notice it.

They all have their pros and cons, I have lots of Coolamp, Tinit and 
Liquid Tin here but still prefer water soluble solder paste. Once 
you've mastered its application using a foam brush it's quite easy to 
use and works best with solder and fluxes since that's what it is.

--- In Homebrew_PCBs@yahoogroups.com, "lcdpublishing" 
<lcdpublishing@...> wrote:
>