At present, there is common consensus from both the industry and the academia that Sn-Ag-Cu alloys will be the primary material for Lead Free solders in the future.
Nevertheless, this Sn-Ag-Cu alloy still causes production problems and defects in assembly practices; for instance:
Because the Spread and Wetting properties of Sn-Ag-Cu are not as desirable as Sn63/Pb37 alloy's, it is common to supply with inert gas (nitrogen) to prevent oxidation when re-flowing, which results in De-wetting in SMT assembly process.
In Wave Soldering, the residue produced from Sn-Ag-Cu alloy is much higher than from
Sn63/Pb37 alloy's, and indirectly causes higher product costs to electronics manufacturers. To overcome these difficulties we introduce you to a 5-element alloy - the Sn-Ag-Cu-Ni-Ge alloy. |
