Improvement in Thermomechanical Reliability of Low Cost Sn-Based BGA Interconnects by Cr Addition

Bang, Junghwan; Yu, Dong-Yurl; Yang, Ming; Ko, Yong-Ho; Yoon, Jeong‐Won; Nishikawa, Hiroshi; Lee, Chang-Woo

doi:10.3390/met8080586

Cited by 9 publications

(2 citation statements)

References 28 publications

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“…Responding to the expiration for the exemption of Pb-bearing automobile electronics in the end of life vehicle (ELV), Ban et al [2] developed a new lead-free solder Sn-Cu-Cr alloy and assessed its performance by means of thermal shock. It was shown that the addition of Cr has the effect of inhibiting the growth of the interfacial Cu 3 Sn layer and, consequently, resulted in higher shear strength than existing commercial solders after 2000 cycles of thermal shock.…”

Section: Contributionsmentioning

confidence: 99%

Intermetallic Alloys

Takasugi

2019

Metals

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Section: Contributionsmentioning

confidence: 99%

Intermetallic Alloys

Takasugi

2019

Metals

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“…Bang et al investigated that the thermomechanical reliability of low-cost Sn-based BGA interconnections improved by Cr Addition. The results show that the presence of Cr in solder inhibits the growth of interfacial Cu 3 Sn layer and the formation of Kirkendall voids, which effectively improves the joint reliability under intense thermal shock condition compared with the commercial SAC305 solders [24].…”

Section: Introductionmentioning

confidence: 96%

The Interface Microstructure and Shear Strength of Sn2.5Ag0.7Cu0.1RExNi/Cu Solder Joints under Thermal-Cycle Loading

Cao

Zhang

Shi

et al. 2019

Metals

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The interface microstructure and shear strength of Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints under thermal-cycle loading were investigated with scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and physical and chemical tests. The results show that an intermetallic compound (IMC) layer of Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints evolved gradually from the scalloped into larger wavy forms with increasing number of thermal cycles. The roughness and average thickness of IMC increased with thermal-cycle loading. However, at longer thermal-cycle loading, the shear strength of the joints was reduced by about 40%. The fracture pathway of solder joints was initiated in the solder seam with ductile fracture mechanism and propagated to the solder seam/IMC layer with ductile-brittle mixed-type fracture mechanism, when the number of thermal cycles increased from 100 to 500 cycles. By adding 0.05 wt.% Ni, the growth of the joint interface IMC could be controlled, and the roughness and average thickness of the interfacial IMC layer reduced. As a result, the shear strength of joints is higher than those without Ni. When compared to joint without Ni, the roughness and average thickness of 0.05 wt.% Ni solder joint interface IMC layer reached the minimum after 500 thermal cycles. The shear strength of that joint was reduced to a minimum of 36.4% of the initial state, to a value of 18.2 MPa.

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