Leadfree solder

Why do we need leadfree solder when
1/ Lead recycling is well established.
2/ Lead in PCBs is only 0.6% of all lead used.
3/ Proliferation of different leadfree alloys are difficult to re-cycle.
4/ Process temp is 30 deg higher giving
a) greater power station emissions
b) greater stress on components
?

 

[Lewish]

Because without it, all those environmental bureaucrats would have to think of something else to safe-guard us from. You know there might be some poor endangered bug that would burrow into a landfill and poison itself on the lead on a discarded circuit board.

 

[BJC]

Lead solder used in copper pipes may be responsible for the general deteroration of society. Stupidity seems to be on the increase. Several theories attribute the fall of Rome to water in lead pipes ( and drinking wine boiled in lead vessals).

 

[shuggie]

Currently we use lead free solder in a high temp high vibration environment, the lead based solder is not as versatile, so there are some advantages. Populating on polyamide substrate requires us to use a very high temp reflow, approx 265'C. This does cause some drop out in weaker components but again selection of devices means a lot. The early drop out is similar to a miltitary standard part, if it survives the stress it usually works pretty well in our application. We also use HALt and HASS screening to assist with latent failure detection and promote infant mortality prior to deployment to the field.
As for the lead, I come from Belfast and our water supply was fed into the homes via lead pipes, never really done us any harm.