A New Low-Temperature Solder Assembly Technique to Replace Eutectic Sn-Bi Solder Assembly

Abstract

We successfully achieved low-temperature assembly by reflowing the 13.5Sn-37.5Bi-45In-4Pb quaternary eutectic solder paste and the SAC 305 solder ball together at 140 °C for 5 min. The wetting angle of the mixed solder joint is 17.55°. The overall atomic percent of Pb in the mixed solder joint is less than 1%, which can be further reduced or eliminated. Moreover, after aging at 80 °C for 25 days, we observed no obvious decrease in shear strength of the fully mixed solder joint, which is the most advantage of this assembly technique over Sn58Bi solder assembly. The Bi phase segregation at the interface is slowed down compared with Sn-Bi solder joint. This low-temperature assembly is promising to be applied in advanced packaging technology to replace the eutectic Sn-Bi solder.

Interfacial morphology and reliability of GaN nanocomposite Sn-Ag-Cu lead-free braze joints

“…This encompasses technologies like system integration packaging and 3D packaging [2] . In this evolving landscape, Snbased solder materials such as Sn-Ag-Cu, Sn-Cu, Sn-Ag [3] , Sn-Zn [4] , and Sn-Bi [5] have gained prominence. Notably, the SAC system is emerging as a favored alternative to Sn-Pb solder, attributed to its comparatively superior performance.…”

Editorial for the Special Issue on Advanced Interconnect and Packaging

“…In particular, Liu et al successfully realize the thermocompression bonding of Pt–Pt metal electrodes through process exploration and form a packaging interconnection that meets the requirements [ 1 ]. Sun et al achieve low-temperature assembly by reflowing 13.5Sn–37.5Bi–45In–4Pb quaternary eutectic solder paste and a SAC 305 solder ball together at 140 °C for 5 min [ 2 ]. Liu et al investigate the flow process of nano glass powder melted at a high temperature [ 3 ].…”