More on lead-free ...

link?

NT

Do go on !

Graham

latest

of

Its a modern form of lemon juice invisible ink. He used the electrons from a lemon+Zn+Cu.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

Oooops, sorry .... :-\

one

similarly Does anyone know the reason for silver migration around the edges of ceramic resonators or the thin element of ceramic filters?. Going ohmic across the faces so operational failure.

one

You hadn't previously heard of tin whiskers ? It's why Swatch asked for a total exemption from the ban on lead in solder.

Graham

Interesting article....

Yes, of course I had heard of tin whiskers. I just thought that it was interesting to see the latest mutterings about the subject, gathered together in one place, and with particular reference to the surface plating of the leadouts on electronic components. I dare say that many others reading on here have not heard of them, so again, another reason to post the link ...

I also felt that the findings that lead had a beneficial effect in preventing the growth of these, was particularly relevant, now that it has been largely banned from solder, except in the cases of equipment which is responsible for human safety, such as avionics, medical instrumentation, and to a debateable degree, military.

Arfa

dings&bespokepage=farnell/en/ed_world/news/latest_news/2006/tin_whiskers.jsp

I seem to remember reading something about that in "Physical Design of Electronic Systems" (which comes in about 6 volumes, by published by Bell Telephone).

I think that the silver migration is affected by the presence of DC voltages and maybe humidity etc., whereas nobody knows how to accelerate tin whisker growth, (so we'll have to wait X years before we find out that everything produced in the last X years is going to fail.....)

Chris