A lot was said about this c. 2005 but the whole discussion seems to have died down.
Here in the UK, most people have now moved to lead free solder. A lot used the Control & Monitoring Equipment ROHS exemption, which is valid till 2017 and this protects you fine if you sell direct to many small customers, but if you have big customers you can't use it because most big firm customers are bullying their supplier base with surveys demanding a confirmation of total compliance on ROHS & REACH...
At work we tested about 30 hand solders and all but two were absolute crap. I cannot see who could use the others - except maybe with a
*very* hot iron e.g. 400C+ and zero quality control. The two which worked both contained silver (SAC solder). One was GBP 45/0.5kg (5x more than normal solder) and the other, which is actually pretty good, is GBP 65 (from Almit in Japan). Per product, the cost of the hand solder is negligible however. Neither of the two flows well; they do good joints but basically the solders stays where you put it. It doesn't like to flow into a gap e.g. if soldering a TO220-style package onto a PCB by the tab on it.But it is in SMT reflow soldering that the whisker troubles happened. I read the Swatch story; obviously they found a solution eventually.
I wonder if perhaps several factors helped:
1) The silver stabilises the solder and stops whisker forming. I found most reflow soldering is done with SAC solder, despite its hugely bigger cost.2) The industry stopped the quest towards ever finer TSOP package pin spacing. We use 0.65mm pitch which is probably OK. The really dense stuff went to BGA which is very well spaced out.
3) Much electronics is consumer stuff and nobody gives a **** if it packs up after a few years...The military retain their exemption for ever, presumably for a good reason.
The problem I have is that out products routinely run for 20 years, in cabinets, at an elevated temp, perhaps +50C.
Any views?