Low-cycle Fatigue of Ag-Based Solders Dependent on Alloying Composition and Thermal Cycle Conditions

Dudek, R.; Faust, W.; Wiese, S.; Rollig, M.; Michel, B.

doi:10.1109/eptc.2007.4469794

Cited by 14 publications

(3 citation statements)

References 3 publications

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“…Deplanque [3] used a grooved lap shear specimen Cu on Cu with 100 µm solder gap height, Pang et al [4] provided measuring results on miniature tensile specimens, and Röllig/Wiese [5] used micro-solderball shear specimens with 200 µm ball height. Obviously, the creep behavior depends on the microstructure of the solder alloy, see also the discussion in [6]. It is therefore of high interest, which of the creep laws would describe the shear test best.…”

Section: Status Of Solder Creep Descriptionsmentioning

confidence: 99%

Theoretical analyses on the shear test

Dudek¹,

Doering²,

Kreyßig

et al. 2010

2010 11th International Thermal, Mechanical &Amp; Multi-Physics Simulation, and Experiments in Microelectronics and Microsystem

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In board manufacturing the shear test is frequently used to evaluate the quality of the solder joints shortly after the soldering process as well as after thermal cycling. The latter evaluation is in particular applied to leadless ceramic components; a certain load drop is linked to solder degradation in a certain region of the joint which is declared "failed" if the load drop of the shear force reaches a predefined limit. However, there are many uncertainties in this evaluation like component misalignment to the shear tool, excessive voiding of the joint or by a fracture mode away from solder bulk failure. As few is known about these effects from a theoretical viewpoint, FE-studies have been performed to close this gap The analyses comprise studies of size effects, misalignment, and voiding on the shear force response. Additionally, the simulated solder creep response was compared to the measured one to check for the validity of creep laws for SAC solder. For a realistic creep rate range reached in low cycle fatigue, very low shear velocities have to be applied to the joints. A new shear tester was designed with shear velocities down to 1 nm/s to reach this goal.

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Section: Status Of Solder Creep Descriptionsmentioning

confidence: 99%

Theoretical analyses on the shear test

Dudek¹,

Doering²,

Kreyßig

et al. 2010

2010 11th International Thermal, Mechanical &Amp; Multi-Physics Simulation, and Experiments in Microelectronics and Microsystem

Self Cite

View full text Add to dashboard Cite

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“…Most models used to determine the number of cycles to failure are empirical, based on Coffin-Manson curves and were developed for eutectic Sn-Pb. 69 The Coffin-Manson model 70,71 uses the Weibull fatigue life data and links the creep strain that has accumulated over one thermal cycle to the number of mean cycles to failure. It predicts the number of cycles needed to lead to failure of a given percentage of parts when exposed to temperature variations.…”

Section: Coffin-manson Cycle To Failure Relationshipmentioning

confidence: 99%

“…Creep hysteresis curves for various Sn–Pb and SAC solders of chip resistor during 90 min thermal cycle from 150 to −40°C at constant strain range69…”

Section: Life Time Predictions Of Pb-free Electronic Assembliesmentioning

confidence: 99%

Reliability of Pb-free solders for harsh environment electronic assemblies

Desmarest

2012

Materials Science and Technology

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Since 2006 and the implementation of environmental regulations, the electronic industry has moved to Pb-free solders. Harsh environment industries that were exempted from the regulations will soon have to follow suit. However, a suitable replacement solder for use in harsh environments still has to be validated and reliability models are yet to be established. In this review, research that led to the selection of currently used Pb-free alloys and the continuing search for high reliability alloys are described. Sn pest and Sn whiskers, potential major threats for electronics operating in harsh environments, are highlighted. This review also focuses on the microstructure, mechanical properties and deformation mechanisms of Pb-free alloys. Emphasis is placed on Sn–Ag–Cu alloys, now considered to be the alloys of choice for replacement of Sn–Pb solders. The reliability of Pb-free electronic assemblies is studied, focusing on thermal fatigue, believed to be the main source of failure through creep–fatigue mechanisms. The validity of models for Pb-free solder joints life time prediction is assessed and the lack of cohesiveness among the available reliability data is examined.

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