Open AccessTemperature dependency of the growth rate of (Cu,Ni)6Sn5 on Cu-xNi substrates
Author(s) -
Xin Tan,
Nurul Razliana Abdul Razak,
Muhammad Hafiz Husain,
Stuart D. McDonald,
Kazuhiro Nogita
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/701/1/012007
Subject(s) - intermetallic , materials science , soldering , substrate (aquarium) , growth rate , melting point , metallurgy , alloy , phase (matter) , diffusion , precipitation , composite material , thermodynamics , chemistry , oceanography , geometry , mathematics , organic chemistry , physics , geology , meteorology
Cu 6 Sn 5 is the most common intermetallic compound (IMC) in lead-free solder joints, and is also a promising anode material for advanced lithium-ion batteries. It has been reported that the growth rates of (Cu,Ni) 6 Sn 5 in Sn-based solder alloy/Cu-xNi substrate couples are greatly accelerated compared to the intermetallic layers that form on a pure Cu substrate. Due to the faster growth rates, solidification can progress through a transient-liquid-phase reaction in commercially relevant timeframes. The complete reaction of the liquid Sn in the couple will result in a joint that is stable at high temperatures. Furthermore, the presence of Ni in the intermetallic suppresses the formation of a Cu 3 Sn layer and stabilises the (Cu,Ni) 6 Sn 5 preventing a polymorphic transformation on cooling along with the associated induced strains. This study investigates the growth rates of (Cu,Ni) 6 Sn 5 in Sn/Cu-xNi couples, where 0 <= x <= 14 wt%, and reports on the effect of temperature on the growth rates at temperatures above the melting point of Sn (231.9°C) between 232°C and 300°C. The results show the highest growth rates occur in the Sn/Cu-6Ni couples, and there is an increase of the (Cu,Ni) 6 Sn 5 growth rate with increasing temperature due to faster diffusion and reaction rates.