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Effects of Aging on Interface Mechanical Properties of Solder Joints of Sn -3.5 Ag and Sn - 3.5 Ag -1.0 Zn Solder Alloys
Published
Author(s)
D J. Lee, Chu-Shik Kang, D H. Baek, K K. Lee, Kil-Won Moon, C A. Handwerker
Abstract
The effects of thickening of intermetallic compound layers formed at the interface and shear properties of solder joints were studied as a function of aging treatment for lead-free solders. The modified double lap shear test method was employed in order to measure the shear strength and shear strain. The test specimens were prepared with Sn - 3.5 Ag and Sn - 3.5 Ag - 1.0 Zn solders and were aged up to 2880 hours at 423 K.Intermetallic compound layers at the interface between Sn - 3.5 Ag solders and Cu substrate kept growing depending on aging times. The coarsenedCu6Sn5 intermetallic compounds led to a deterioration of the shearproperties of solder joints by changing the crack propagation path and decreasing shear strength of the solder joint. Adding 1.0 % mass fractionof Zn to Sn - 3.5 Ag, however, suppressed Cu6Sn5 intermetallic compound growth markedly by forming a Cu-Zn-Sn layer. This Cu-Zn-Sn layer acted as adiffusion barrier between Cu6Sn5 and Sn - 3.5 Ag - 1.0 Zn solders while aging treatments. Thus, Sn - 3.5 Ag - 1.0 Zn solders had higher shearstrength and higher strain to fracture than those of Sn - 3.5 Ag / Cu solder joints.
Lee, D.
, Kang, C.
, Baek, D.
, Lee, K.
, Moon, K.
and Handwerker, C.
(2021),
Effects of Aging on Interface Mechanical Properties of Solder Joints of Sn -3.5 Ag and Sn - 3.5 Ag -1.0 Zn Solder Alloys, Journal of Japanese Institute of Metals
(Accessed October 9, 2025)