The electronics industry will mostly be ready for the July 1, 2006 RoHS deadline, but engineers in the exempt defense and aerospace industries still have concerns about the transition to lead-free components. For one, the exempt industries have spent the past two decades shifting away from pricey hi-reliability parts in favor of the less costly off-the-shelf (OTS) commercial components.
Many of those OTS parts are now entirely lead-free, which leaves the exempt industries in a bind, as they may find themselves unable to get leaded versions of the components they need. We checked in with a Lockheed Martin engineer on the difficulties, who reported, "We're seeing problems with suppliers changing the lead finish and not notifying us that they have changed from SnPb to Sn or whatever."
He points to other RoHS-oriented problems. "We're seeing process problems associated with wicking of the solders to the very small package contacts — I believe this may be a surface-tension problem." He is experiencing additional costs due to the need to develop and qualify new processes. He also notes there are problems due to the "higher melting point of the new finishes — we do not know what the proportions of the mix should be." Finally, he says "there is still no data on the long-term performance of the replacement materials."