Premium
Interfacial reactions between In–48Sn solder and electroless nickel/immersion gold substrate during reflow process
Author(s) -
Koo JaMyeong,
Yoon JeongWon,
Jung SeungBoo
Publication year - 2006
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.2193
Subject(s) - ball grid array , soldering , materials science , intermetallic , metallurgy , transmission electron microscopy , scanning electron microscope , substrate (aquarium) , layer (electronics) , reflow soldering , nickel , composite material , nanotechnology , oceanography , alloy , geology
In this study, the interfacial reactions of In–48Sn solder balls on an electroless Ni/immersion Au (ENIG) ball grid array (BGA) substrate during reflow at 170 °C for up to 1800 s were investigated using SEM, transmission electron microscope (TEM) and energy dispersive X‐ray spectroscope (EDS) analyses. During the initial 10 s of the reflow process, AuIn 2 cubes and a continuous Ni 3 (Sn,In) 4 intermetallic compound (IMC) layer were formed at the interface between the solder and the substrate. The thickness of the Ni 3 (Sn,In) 4 layer was found to increase from approximately 140 nm to 1 µm, as the reflow time increased from 10 to 1800 s, respectively. The transformation of Ni to form the Ni 3 (Sn,In) 4 IMC led to the formation of a P‐rich Ni (hereafter Ni 3 P) layer between the Ni 3 (Sn,In) 4 IMC and the ENIG substrate, whose thickness increased with increasing the reflow time. Copyright © 2006 John Wiley & Sons, Ltd.