Publisher Summary Lead-free soldering is an unstoppable global trend because of both environmental concerns and business considerations. Consensus gradually developed on the mainstream options and eutectic Sn-Ag-Cu appears to be the most popular choice for reflow applications. Sn-Ag-Bi systems also receive great attention because of their high reliability, in the absence of lead, and processability. Perhaps, the logical choice will be to use Sn-Ag-Cu in phase one, but to use Sn-Ag-Bi-X system in phase two when lead contamination is no longer an issue. Furthermore, challenges for using lead-free alloys are inevitable.