Homebrew PCBs

The tin will not grow whiskers if you use a urethane over coat. The new ROSH 
solder will grow whiskers too!

Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"

----- Original Message ----- 
From: "fredbutz" <fredbutz@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, August 20, 2010 10:31 AM
Subject: [Homebrew_PCBs] Re: Now, tinning


Just as an FYI, when I do use the tin, I do it after the solder mask.
So there aren't any traces to change the impedance.

But while were on the negatives.  :)

There are also cases where the tin plate grows whiskers over time and can 
cause a short later in life.  If you google for tin plating whiskers you'll 
see it.

--- In Homebrew_PCBs@yahoogroups.com, Malcolm Parker-Lisberg 
<mparkerlisberg@...> wrote:
>
> Alessio
>
> It does not short two tracks, but adds a high value of resistance between 
> the tracks, more of a problem on low power digital and analogue systems.
>
> Malcolm
>
> I don't suffer from insanity I enjoy it!
>
> --- On Fri, 8/20/10, Alessio Sangalli <alesan@...> wrote:
>
> From: Alessio Sangalli <alesan@...>
> Subject: Re: [Homebrew_PCBs] Re: Now, tinning
> To: Homebrew_PCBs@yahoogroups.com
> Date: Friday, August 20, 2010, 5:27 PM
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> \ufffd
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>       On 08/20/2010 03:15 AM, Malcolm Parker-Lisberg wrote:
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> > Looks good, thanks, nice to know the formula works. One thing I found
>
> > with electroless tin was that when used on PCB tracks on a high
>
> > impedance circuit, was the tin seemed to coat the non-copper areas of
>
> > the FR4 board and significantly reduce the impedance.
>
>
>
> I am not a very "analog" guy because I think in terms of "short" or
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> "open". What do you mean exactly here? Is the tinning "shorting" tracks?
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>
> My question at this point: we saw it works of a "solid" PCB, but how
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> good is it on an etched circuit?
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> bye
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> as
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> [Non-text portions of this message have been removed]
>




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