Microstructure Evolution During the Aging at Elevated Temperature of Sn-Ag-Cu Solder Alloys

Morando, C.; Fornaro, Osvaldo; Garbellini, O.; Palacio, H.

doi:10.1016/j.mspro.2012.06.011

Cited by 9 publications

(13 citation statements)

References 6 publications

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“…Compared with the as-reflow condition (see Figure 3), Ag 3 Sn IMC coarsened and their fraction decreased upon 48 h of aging. This is consistent with dissolution and re-precipitation of Ag 3 Sn reported in the previous reports [30,31] Further, coarsening of Ag 3 Sn IMC appears to be higher for SAC 305-ZrO 2 B/Cu joint. ZrO 2 A NPs dispersed in the solder matrix have contributed to a finer Ag 3 Sn re-precipitation upon aging and thereby responsible for their higher shear strength.…”

Section: Effect Of Zro2 Nanoparticle Size On the Shear Strength And Fsupporting

confidence: 92%

Shear Strength and Aging Characteristics of Sn-3.0Ag-0.5Cu/Cu Solder Joint Reinforced with ZrO2 Nanoparticles

Rajendran

Hwang

Jung

2020

Metals

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This study investigates the shear strength and aging characteristics of Sn-3.0Ag-0.5Cu (SAC 305)/Cu joints by the addition of ZrO2 nanoparticles (NPs) having two different particle size: 5–15 nm (ZrO2A) and 70–90 nm (ZrO2B). Nanocomposite pastes were fabricated by mechanically mixing ZrO2 NPs and the solder paste. ZrO2 NPs decreased the β-Sn grain size and Ag3Sn intermetallic compound (IMC) in the matrix and reduced the Cu6Sn5 IMC thickness at the interface of lap shear SAC 305/Cu joints. The effect is pronounced for ZrO2A NPs added solder joint. The solder joints were isothermally aged at 175 °C for 24, 48, 144 and 256 h. NPs decreased the diffusion coefficient from 1.74 × 10–16 m/s to 3.83 × 10–17 m/s and 4.99 × 10–17 m/s for ZrO2A and ZrO2B NPs added SAC 305/Cu joints respectively. The shear strength of the solder joints decreased with the aging time due to an increase in the thickness of interfacial IMC and coarsening of Ag3Sn in the solder. However, higher shear strength exhibited by SAC 305-ZrO2A/Cu joints was attributed to the fine Ag3Sn IMC’s dispersed in the solder matrix. Fracture analysis of SAC 305-ZrO2A/Cu joints displayed mixed solder/IMC mode upon 256 h of aging.

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Section: Effect Of Zro2 Nanoparticle Size On the Shear Strength And Fsupporting

confidence: 92%

Shear Strength and Aging Characteristics of Sn-3.0Ag-0.5Cu/Cu Solder Joint Reinforced with ZrO2 Nanoparticles

Rajendran

Hwang

Jung

2020

Metals

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“…Figure 9(a) corresponds to the heating of Sn-Cu eutectic alloy starting from ascast condition, and with artificial aging at 453 K during 24, 48 and 96 h, while Figure 9(b) to Sn-Ag eutectic alloy and Figure 9(c) to Sn-Ag-Cu ternary eutectic alloy for as-cast and similar aging time, respectively. As previously reported (Morando et al, 2012), for aging in the range of 24 to 48 h, the samples showed a decrease in the Vickers microhardness and then an increasing starting from 96 h of aging, reaching the original values of the as-cast condition.…”

Section: Solidification Microstructuressupporting

confidence: 85%

Influence of aging on microstructure and hardness of lead-free solder alloys

Morando

Fornaro

2020

SSMT

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Purpose The purpose of this paper is to carry out a study of the evolution of the microstructure and the microhardness of Sn-Cu-Ag alloys from as-cast condition and under artificial isothermal aging at different temperatures (100ºC and 180ºC) for a treatment time up to 500 h. A comparison with Sn-37% Pb eutectic solder samples was also made. Design/methodology/approach Sn-3.5%Ag, Sn-0.7%Cu and Sn-3.5%Ag-0.9%Cu were poured in two different cooling rate conditions and then aged at 100ºC (373ºK) and 180 °C (453ºK) during 500 h. Microstructural changes were observed by optical microscopy, scanning electron micrograph and energy dispersive X-ray microanalysis. Differential scanning calorimetry technique (DSC) was also used to confirm the obtained results. Findings A decrease up to 20% in microhardness respect to the value of the as-cast alloy was observed for both aging temperatures. These changes can be explained considering the coarsening and recrystallization of Sn dendrites present in the microstructures of all the systems studied. Originality/value There is no evidence of dissolution or precipitation of new phases in the range of studied temperatures that could be detected by DSC calorimetry technique. The acting mechanisms must be the result of coarsening of Sn dendrites and the residual stresses relaxation during the first stages of the isothermal aging.

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“…Pre-ingots were poured into a 10 mm internal diameter by 120 long cylinders. Firstly the binary eutectics Sn-0.9%Cu and Sn-3.5%Ag were obtained and used as mother alloy, Morando et al (2012). Ternary eutectic composition Sn-3.5%Ag-0.9%Cu was obtained by the addition of Ag and Cu to the previously Fig.…”

Section: Methodsmentioning

confidence: 99%