Homebrew PCBs

HEllo Group...

I tried using the toner transfer method, and got the PCB latternt o transfer,a nd had no problems getting the paper off the board.  HOWEVER...

When I mixed a solution of 1 parts of Muriatic acid with 2 parts of Hydrogen Peroxide, I started ectching the board, and it actually ate the traces OFF the board! What did I do wrong?

Thanks in advance...

Kim


[Non-text portions of this message have been removed]

On Mon, 19 Dec 2005 05:17:39 +0100, Kim Currier <kimcurrier@...>  
wrote:

> HEllo Group...
>
>
> I tried using the toner transfer method, and got the PCB latternt o  
> transfer,a nd had no problems getting the paper off the board.
> HOWEVER...
>
>
> When I mixed a solution of 1 parts of Muriatic acid with 2 parts of  
> Hydrogen Peroxide, I started ectching the board, and it actually ate
> the traces OFF the board! What did I do wrong?
>
>
> Thanks in advance...
>
>
> Kim


What sort of concentrations are we talking here with the wet chemicals?
If it is anywhere near what they are sold here you made a much too strong  
etchant that will eat just about anything ;-)

If there wasn't a violent reaction with bubbles and stuff your etchant  
wasn't too strong and there's a problem with the resist/toner.

ST

It wasn't a violent reaction, but there WAS some buibbles initially. THe
traces were only  a 16th of an inch, but, it seemed to take it right off the
board...

Kim

----- Original Message ----- 
From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, December 20, 2005 12:12 PM
Subject: Re: [Homebrew_PCBs] Newbie to PCB's...


> On Mon, 19 Dec 2005 05:17:39 +0100, Kim Currier <kimcurrier@...>
> wrote:
>
> > HEllo Group...
> >
> >
> > I tried using the toner transfer method, and got the PCB latternt o
> > transfer,a nd had no problems getting the paper off the board.
> > HOWEVER...
> >
> >
> > When I mixed a solution of 1 parts of Muriatic acid with 2 parts of
> > Hydrogen Peroxide, I started ectching the board, and it actually ate
> > the traces OFF the board! What did I do wrong?
> >
> >
> > Thanks in advance...
> >
> >
> > Kim
>
>
> What sort of concentrations are we talking here with the wet chemicals?
> If it is anywhere near what they are sold here you made a much too strong
> etchant that will eat just about anything ;-)
>
> If there wasn't a violent reaction with bubbles and stuff your etchant
> wasn't too strong and there's a problem with the resist/toner.
>
> ST
>
>
>
> Be sure to visit the group home and check for new Links, Files, and
Photos:

> http://groups.yahoo.com/group/Homebrew_PCBs
>
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> Yahoo! Groups Links
>
>
>
>
>
>
>
>
> -- 
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>
>

On Wed, 21 Dec 2005 00:32:18 +0100, Kim Currier <kimcurrier@...>  
wrote:

> It wasn't a violent reaction, but there WAS some buibbles initially. THe
>
> traces were only  a 16th of an inch, but, it seemed to take it right off  
> the
>
> board...
>
>
> Kim


That's what, 1.5mm? (I'll never understand how you guys manage to think in  
16th of something ;-) That shouldn't just "vanish" even in a very strong  
etchant.
Do you have a picture or something of the transfer? It must be a real  
solid layer of toner.

You can try to transfer on the now blank PCB again, then hold against  
light and look if you can see through the toner. Since there's no copper  
you'll see the toner density.

ST