[time-nuts] OT: RoHS crap

[Chuck Harris]

Michael Sokolov wrote:
> Hello again,
> 
> Thanks to everyone who has replied to my query!
> 
> I have a few additional questions though:
> 
> 1. What about the tin whiskers?  Will they be eliminated by using SnPb
> solder, or will they always remain a potential problem when one is
> forced to use a Pb-free part?

No, because the lead solder only wicks up the leads so far.  The crinkles
made by the crystalization make perfect launching points for whiskers.

> 
>> It is fun to watch the RoHS parts as they reach soldering temperature.
>> the shiny finish turns to a mossy crinkle finish, like a wrinkle finish
>> paint job.  What you are seeing is the electroplated finish crystalize.
> 
> That's what I was referring to above -- if I use the standard (lower
> temperature) SnPb process, the above will never happen, right? 

No one solders at exactly the melting point of the solder.  I use a 350C
iron to melt 67/37 solder.  350C is easily hot enough to melt the non lead
solder.  It just isn't hot enough to make it pretty.

-Chuck Harris