Interfacial Reactions Between In-Sn Solder and Ni-Fe Platings

• Published in: Journal of electronic materials Vol. 38; no. 12; pp. 2506 - 2515
• Main Authors: Daghfal, John P., Shang, P. J., Liu, Z. Q., Shang, J. K.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Boston Springer US 01.12.2009; Springer; Springer Nature B.V
• Subjects: Applied sciences; Brazing. Soldering; Characterization and Evaluation of Materials; Chemistry and Materials Science; Crystals; Electronics and Microelectronics; Exact sciences and technology; Instrumentation; Intermetallic compounds; Joining, thermal cutting: metallurgical aspects; Kinetics; Materials Science; Metals. Metallurgy; Optical and Electronic Materials; Soldering; Solid State Physics; faceting; In-Sn solder; Ni-Fe metallization; FeSn; Ni; Sn; interface; Cubic lattices; Crystal form; Tin alloy; Metallizing; Iron; Solder; Eutectic; Interface reaction; Scanning transmission electron microscopy; Activation energy; Copper alloy; Scanning electron microscopy; Annealing; Intermetallic compound; Faceting; Transmission electron microscopy; Morphology; Soldered joint; Plating; Nickel; Kinetics; Microstructure; Interface; Bilayers
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-009-0896-y

Interfacial interactions in a Ni- x Fe-Sn-In eutectic solder ( x  = 30 at.%, 55 at.%) have been examined. Transmission and scanning electron microscopy (TEM/SEM) were utilized to investigate the structure, composition, and morphology of the intermetallic compounds (IMCs). Upon reflow, Ni 3 Sn 4 and FeSn 2 phases appeared at the interface along with Cu 6 Sn 5 in the solder. Annealing experiments revealed the formation of a bilayer IMC that was Fe-rich adjacent to the Ni-Fe metallization and Ni-rich on the solder side. Kinetic studies established the apparent activation energies for both systems to be 51.8 kJ/mol and 85.1 kJ/mol, for 30 at.% and 55 at.% Fe contents, respectively. In the Fe-rich system, globular Ni 3 Sn 4 crystals were formed upon reflow, but were changed into a cubic/faceted structure after annealing.