| 摘要 |
A lead-free solder alloy composition comprising tin, silver and copper, and a process for reflow soldering for minimizing tombstoning frequency are disclosed. In one particular exemplary embodiment, the lead-free Sn-Ag-Cu solder alloys for minimizing the tombstoning effect of the present disclosure display high mass fraction during melting and prolonged melting as shown by a widened DSC peaks, that allows for a balanced surface tension on both ends of the chip component to develop. In accordance with further aspects of this exemplary embodiment, the alloys display a mass fraction of solid during melting greater than 20% and a DSC peak width greater than 8 <°>C< >using a 5 <°>C/min scan rate. In accordance with further aspects of this exemplary embodiment, the alloy comprises on a weight basis Ag 1-4.5 %, Cu 0.3-1% balanced with Sn. |
