Re: gEDA-user: Lead Free at home?

[Dave <dgriffi@xxxxxxxxxxxxx>]

On Mon, 22 Aug 2005, Marvin Dickens wrote:

> I don't know. I've never bought it - although, I've made it. This type of
> plate is really, really thin. As a comparison, a contractor grade garbage bag
> is 3 mills in thickness. With immersion, your guaranteed 2 mills and possibly
> 2.5 mills if the workflow is really good and there is no contamination. Rub on
> plating gives only a few molecules of thickness.
>
> Both rub on and immersion are what is know as self limiting because as soon as
> there is no exposed copper, the reaction stops. But, with immersion, the coat
> is applied in an extremely uniform system under more ideal circumstances than
> something being rubbed on (Immersion, like electroless and electroplating
> yields a very uniform plate).

I think I'm convinced of your tin-silver immersion plating.  A few more
questions, if you don't mind:  Once you mix up a liter of this stuff, how
long can you keep it before it goes bad?  How many times can you dip
circuit boards in it before the solution is exhausted?

I think I can borrow a chemistry lab to make this stuff.


-- 
David Griffith
dgriffi@xxxxxxxxxxxxx