Study on Ni-GNSs enhanced Sn2.5Ag0.7Cu0.1RE/Cu solder joints β-Sn grain orientation and interfacial IMC growth kinetics under constant temperature thermomigration

• DOI: 10.1016/j.matchar.2023.113263
• Publication Date: 2023-08-21T15:11:45Z
• Authors: Chao Zhang; Keke Zhang; Yijie Gao; Yuming Wang; Ruiqing Hou
• Keywords: Liquation; Kirkendall Effect; Solidus

Aiming at the thermomigration problem caused by large temperature gradient (TG) of micro-soldering joints, a constant device with control function was designed and manufactured. This paper studied polarity phenomenon, crystallographic characteristics, interfacial intermetallic compound (IMC) growth kinetics Ni-GNSs reinforced Sn2.5Ag0.7Cu0.1RE/Cu solder joints under thermomigration. The results indicate that exhibited significant phenomenon conditions TG ≥ 1000 °C/cm θ ≤ 43.5° between c-axis β-Sn grains. At cold end joint, Cu6Sn5 phase interface gradually thickens forms Cu3Sn on substrate side, while microcracks expanded developed into macrocracks. hot interface, dissolved. accompanied "Kirkendall voids" formed cracks joint until "fully IMC joint" formed. came before IMC. average were correlated IMC, leading to formation due oversaturation Cu atoms. addition 0.05 wt% refines grain structure increases activation energy for suppressing phenomenon.