[Amps] BeO in tubes/tinwhiskers

[Steve Thompson]

I was musing on this overnight - tin 'whiskers' with lead free 
solder is an issue in where there's very fine line spacing on 
component legs/pcbs. I think there's a different problem we'll 
see, and probably more so in high power applications.

Tin/lead solder is soft and ductile. It absorbs a lot of 
mechanical stress, especially thermal expansion/contraction stress 
(which can be enormous, even at tiny movements). Lead free solder 
is harder and appears not to adhere to metal as well. More stress 
is going to be transferred into components. I suspect there will 
be joint and component failures where there's thermal extremes or 
cycling. I hope I'm proved wrong.

Steve