Re: Atmospheric Effect on Dendrite Growth



> On Wed, 20 Jul 2005 09:16:04 +0200, Dieter Britz wrote:
>
> > WAYNEL wrote:
> >> I am trying to calculate if the atmosphere has an affect on the growth
> >> of dendrites, e.g. copper. Eliminating the atmosphere and growing
> >> dendrites in a vacuum may prove to be difficult to run, as the
> >> electrolyte will outgas and thus evaporate.
> >> However, if a test was constructed using Argon or any other inert gas
> >> would one notice an effect?
> >> Consider another test. Rather than using an inert gas, used CO2, could
> >> this effect the growth of a dendrite.
> >> Are there papers on the atmospheric effect on dendrite growths?
> >> Can anyone propose any potential effects the atmosphere may have?
> >> Or is the electrolyte the "dendrite's atmosphere" and this
> >> vehicle may pick up atmospheric contaminates that could produces
> >> various species?
> >
> > Oxygen would of course be reduced along with Cu++, and it's
> > hard to say whether this could affect dendrite growth. My guess
> > is not, but I can't be sure. Since you are experimenting with it,
> > try it out. Certainly I would be pretty confident that an Ar
> > atmosphere would not affect dendrites, as Ar is inert, and it is
> > hard to see how the small ampount that would dissolve in the
> > electrolyte could have any effect at all. CO2 - well, hard to say.
> > It would affect the pH, and that itself might cause a change.
>

Back in the 70's, we had a problem with dendritic growth inside of T-03
power transistor cases. The experts at the time couldn't determine the
cause but speculated that it was due to migration of the hard die
solder. How and why was never explained. The lot of transistors was
replaced and the problem "went away."

Al
.