Cyclic Mechanical Durability of Sn3.0Ag0.5Cu Pb-Free Solder Alloy

Electronic and Photonic Packaging, Electrical Systems Design and Photonics, and Nanotechnology ◽

10.1115/imece2005-81171 ◽

2005 ◽

Cited By ~ 6

Author(s):

Gayatri Cuddalorepatta ◽

Abhijit Dasgupta

Keyword(s):

Room Temperature ◽

Strain Range ◽

Cyclic Strain ◽

Inelastic Strain ◽

Mechanical Tests ◽

Test System ◽

Snagcu Solder ◽

Mechanical Durability ◽

Free Solder

The isothermal mechanical durability properties of a hypoeutectic, Sn3.0Ag0.5Cu solder are presented and compared to that of near-eutectic Sn3.9Ag0.6Cu and of baseline eutectic Sn37Pb solder. Cyclic mechanical tests are performed at room temperature at various load levels, using a custom-built thermo-mechanical-microscale (TMM) test system. Both the SnAgCu solders are found to outperform the baseline Sn37Pb, with near-eutectic Sn3.9Ag0.6Cu having the best durability. These trends are found to be in agreement with similar results available in the literature for thermal cycling durability. Fatigue results are presented in terms of both cyclic strain range and cyclic work dissipation. The effect of microstructural coarsening resulting from long-term aging at room temperature is investigated by conducting similar tests at room temperature, on the aged samples. The durability of the hypoeutectic SnAgCu solder reduced on aging, with the drop being more significant for damage curves based on cyclic work dissipation, than on cyclic inelastic strain range.

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Creep and High-Temperature Isothermal Fatigue of Pb-Free Solders

2003 International Electronic Packaging Technical Conference and Exhibition, Volume 2 ◽

10.1115/ipack2003-35361 ◽

2003 ◽

Cited By ~ 6

Author(s):

Qian Zhang ◽

Abhijit Dasgupta ◽

Peter Haswell

Keyword(s):

High Temperature ◽

Strain Range ◽

Inelastic Strain ◽

Propagation Rate ◽

Mechanical Tests ◽

Test System ◽

Load Drop ◽

Homologous Temperature ◽

Free Solder ◽

Sn37pb Solder

The creep resistance of Sn3.9Ag0.6Cu Pb-free solder alloy is compared to that of the baseline eutectic Sn37Pb solder at comparable homologous temperatures. Sn3.9Ag0.6Cu is significantly more creep-resistant than Sn37Pb solder. The isothermal cyclic mechanical durability of Sn3.5Ag and Sn3.9Ag0.6Cu Pb-free solder alloys are presented and compared to that of the baseline eutectic Sn37Pb solder at comparable homologous temperature. Cyclic mechanical tests are performed at high temperature at various strain-rates and load levels, using a thermo-mechanical-microstructural (TMM) test system developed by the authors. The data is analyzed using standard power-law durability models based on 50% load drop, using cyclic work and cyclic inelastic strain range. The durability curve of Sn3.9Ag0.6Cu Pb-free solder is found to have the largest slope, followed by the Sn3.5Ag solder and finally the baseline Sn37Pb eutectic solder, under the test conditions investigated. At a homologous temperature of 0.75, Sn3.9Ag0.6Cu shows the best durability, while Sn3.5Ag and Sn37Pb have very similar durability performance according to damage relations based on either work or inelastic strain range. The damage propagation rate is also estimated for all three solders, based on the load drop rate, and plotted vs. cyclic work and cyclic inelastic strain range.

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Cyclic Mechanical Durability of Sn-3.9Ag-0.6Cu and Sn-3.5Ag Lead-Free Solder Alloys

Electronic and Photonic Packaging, Electrical Systems Design and Photonics, and Nanotechnology ◽

10.1115/imece2002-39250 ◽

2002 ◽

Cited By ~ 4

Author(s):

Qian Zhang ◽

Abhijit Dasgupta ◽

Peter Haswell

Keyword(s):

Thermal Cycling ◽

Strain Range ◽

Mechanical Tests ◽

Test System ◽

Lead Free ◽

Lead Free Solder ◽

Solder Alloys ◽

Mechanical Cycling ◽

Mechanical Durability ◽

Free Solder

The isothermal mechanical durability properties of two lead-free solder alloys, Sn3.5Ag and Sn3.9Ag0.6Cu, are presented and compared to that of the baseline eutectic Sn37Pb solder. Cyclic mechanical tests are performed at room temperature at various strain-rates and load levels, using a thermo-mechanical-microstructural (TMM) test system developed by the authors. The data is analyzed using standard power-law durability models based on work and inelastic strain range. The Sn3.9Ag0.6Cu lead-free alloy is found to be most durable, followed by the Sn3.5Ag solder and finally the baseline Sn37Pb eutectic alloy, under the test conditions investigated. However, tests at high load levels show a greater difference in durability than tests at low load levels. This trend is the opposite of that reported in the literature for thermal cycling durability. A hypothesis is put forward to explain the observed differences between mechanical cycling and thermal cycling, based on the energy-partitioning damage model.

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Isothermal Mechanical Durability of Three Selected PB-Free Solders: Sn3.9Ag0.6Cu, Sn3.5Ag, and Sn0.7Cu

Journal of Electronic Packaging ◽

10.1115/1.2056569 ◽

2005 ◽

Vol 127 (4) ◽

pp. 512-522 ◽

Cited By ~ 17

Author(s):

Qian Zhang ◽

Abhijit Dasgupta ◽

Peter Haswell

Keyword(s):

Strain Rate ◽

Room Temperature ◽

Strain Range ◽

Inelastic Strain ◽

Total Strain Range ◽

Homologous Temperature ◽

Test Conditions ◽

Mechanical Durability ◽

Virtual Qualification ◽

The Eu

This study is motivated by the urgent need in the electronics industry for mechanical properties and durability of Pb-free solders because the use of Pb will be banned in the EU by July 1, 2006. The isothermal mechanical durability of three NEMI recommended Pb-free solders, 95.5Sn-3.9Ag-0.6Cu, 96.5Sn-3.5Ag, and 99.3Sn-0.7Cu, is tested on the thermo-mechanical-microscale (TMM) setup under two test conditions: room temperature and relatively high strain rate, and high temperature and low strain rate. The test data are presented in a power law relationship between three selected damage metrics (total strain range, inelastic strain range, and cyclic work density) to 50% load drop. The obtained mechanical durability models of three Pb-free solders are compared with those of the eutectic 63Sn-37Pb solder at the two selected test conditions and at the same homologous temperature of 0.75. The results of this study can be used for virtual qualification of Pb-free electronics during design and development of electronics under mechanical loading.

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G0300101 Proposal of Acquisition Way of Inelastic Strain Range Using Lead-Free Solder Lap Joint Type Shear Specimen

The Proceedings of Mechanical Engineering Congress Japan ◽

10.1299/jsmemecj.2015._g0300101- ◽

2015 ◽

Vol 2015 (0) ◽

pp. _G0300101--_G0300101-

Author(s):

Takeharu HAYASHI ◽

Hirohiko WATANABE ◽

Yoshinori EBIHARA ◽

Jyo SHIMURA

Keyword(s):

Strain Range ◽

Inelastic Strain ◽

Lead Free ◽

Lead Free Solder ◽

Lap Joint ◽

Shear Specimen ◽

Free Solder

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Влияние микролегирования иттрием и гафнием на прочностные характеристики и морфологию карбидной фазы сплава ЖС3ДК-ВИ при замедленной кристаллизации

Aerospace technic and technology ◽

10.32620/aktt.2021.4sup1.17 ◽

2021 ◽

pp. 125-131

Author(s):

Татьяна Владимировна Тихомирова ◽

Елена Ивановна Гордиенко ◽

Руслан Васильевич Бехтер ◽

Александр Витальевич Подобный

Keyword(s):

Carbide Phase ◽

Room Temperature ◽

Crystallization Rate ◽

Tensile Tests ◽

Mechanical Tests ◽

Treatment Temperature ◽

Strength Characteristics ◽

Technological Parameters ◽

Heat Resistant

There are analyzed the melts of the ZhS3DK-VI alloy with different levels of strength characteristics and the factors influencing their reduction, differences in the macro and microstructure of the alloy, the effect of the crystallization rate when pouring the melt into hot and cold ceramic molds are determined. Since when casting parts, the level of properties is determined on separately cast samples, in the technology of manufacturing samples, the casting parameters of the corresponding part must be observed, and when increasing the strength characteristics due to changing technological parameters, it is imperative to consider the possibility of changing the technology of casting parts. However, for parts of complex configuration, cast from heat-resistant nickel alloys, it is often impossible to change the technology, therefore the only way to influence the properties of the material is to use microalloying with rare earth elements, for example, yttrium and hafnium. The introduction of these alloying elements in small amounts has a positive effect on factors that reduce the properties of the ZhS3DK-VI alloy, such as the unfavorable shape and topography of the carbide phase, or even slightly change the chemical composition of carbides. The article analyzes the effect of microalloying with hafnium and yttrium on the morphology and topography of the carbide phase; positive changes in the microstructure and strength characteristics at room temperature of the heat-resistant nickel alloy ZhS3DK-VI are noted. The technology of microalloying the melt has been developed to obtain satisfactory valuesof strength characteristics in tensile tests and impact toughness at room temperature. Microalloying the ZhS3DK-VI alloy with hafnium in a concentration of 0.15...0.25 % made it possible to increase the strength characteristics on samples for mechanical tests by 10…15 %, provided that the melt was drained into hot ceramic molds and slowed down. Higher concentrations of hafnium during slow crystallization lead to the formation of eutectic phases uncharacteristic for the ZhS3DK-VI alloy, requiring a decrease in the heat treatment temperature, which, accordingly, leads to a decrease in the level of long-term strength at 850 °C.

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Overview of Fatigue Failure of Pb-Free Solder Joints in CSP/BGA/Flip-Chip Applications

Journal of Microelectronics and Electronic Packaging ◽

10.4071/1551-4897-6.3.149 ◽

2009 ◽

Vol 6 (3) ◽

pp. 149-153 ◽

Cited By ~ 3

Author(s):

Sean M. Chinen ◽

Matthew T. Siniawski

Keyword(s):

Finite Element ◽

Solder Joint ◽

Finite Element Methods ◽

Flip Chip ◽

Snagcu Solder ◽

Design Considerations ◽

Mode Of Failure ◽

Solder Joint Fatigue ◽

Free Solder

The purpose of this paper is to provide an overview of SnAgCu solder joint fatigue in BGA/CSP/flip-chip applications and the concern of long-term reliability. The most common mode of failure is ductile fracture due to creep strain. Several methods of predicting the overall life of the solder joint are the Coffin-Manson approach, a constitutive fatigue law, and a damage based model using FEM (finite element methods). The effects of underfill and its processes as well as design considerations that will increase reliability will also be discussed.

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Effect of Long-Term Room Temperature Aging on the Fatigue Properties of SnAgCu Solder Joint

Journal of Electronic Packaging ◽

10.1115/1.4040105 ◽

2018 ◽

Vol 140 (3) ◽

Cited By ~ 12

Author(s):

Sinan Su ◽

Nianjun Fu ◽

Francy John Akkara ◽

Sa'd Hamasha

Keyword(s):

Fatigue Life ◽

Room Temperature ◽

Solder Joints ◽

Fatigue Behavior ◽

Lead Free ◽

Lead Free Solder ◽

Room Temperature Aging ◽

Free Solder ◽

Temperature Aging

Solder joints in electronic assemblies are subjected to mechanical and thermal cycling. These cyclic loadings lead to the fatigue failure of solder joints involving damage accumulation, crack initiation, crack propagation, and failure. Aging leads to significant changes on the microstructure and mechanical behavior of solder joints. While the effect of thermal aging on solder behavior has been examined, no prior studies have focused on the effect of long-term room temperature aging (25 °C) on the solder failure and fatigue behavior. In this paper, the effects of long-term room temperature aging on the fatigue behavior of five common lead-free solder alloys, i.e., SAC305, SAC105, SAC-Ni, SAC-X-Plus, and Innolot, have been investigated. Several individual lead-free solder joints on printed circuited boards with two aging conditions (no aging and 4 years of aging) have been prepared and subjected to shear cyclic stress–strain loadings until the complete failure. Fatigue life was recorded for each solder alloy. From the stress–strain hysteresis loop, inelastic work and plastic strain ranges were measured and empirically modeled with the fatigue life. The results indicated that 4 years of room temperature aging significantly decreases the fatigue life of the solder joints. Also, inelastic work per cycle and plastic strain range are increased after 4 years of room temperature aging. The fatigue life degradation for the solder alloys with doped elements (Ni, Bi, Sb) was relatively less compared to the traditional SAC105 and SAC305.

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Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

Nuklearmedizin ◽

10.1055/s-0037-1620603 ◽

1977 ◽

Vol 16 (01) ◽

pp. 30-35 ◽

Cited By ~ 1

Author(s):

N. Agha ◽

R. B. R. Persson

Keyword(s):

Complex Formation ◽

Significant Influence ◽

Room Temperature ◽

Ph Value ◽

Maximum Activity ◽

Reduction Step ◽

Labelling Yield ◽

Different Temperatures ◽

Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

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Foldable and washable textile-based OLEDs with a multi-functional near-room-temperature encapsulation layer for smart e-textiles

npj Flexible Electronics ◽

10.1038/s41528-021-00112-0 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

So Yeong Jeong ◽

Hye Rin Shim ◽

Yunha Na ◽

Ki Suk Kang ◽

Yongmin Jeon ◽

...

Keyword(s):

Room Temperature ◽

Wearable Electronics ◽

Ambient Conditions ◽

Light Emitting ◽

Stable Operating ◽

Mechanical Durability ◽

Potential Applications ◽

Wearable Electronic ◽

Data Signal ◽

Wearable Electronic Devices

AbstractWearable electronic devices are being developed because of their wide potential applications and user convenience. Among them, wearable organic light emitting diodes (OLEDs) play an important role in visualizing the data signal processed in wearable electronics to humans. In this study, textile-based OLEDs were fabricated and their practical utility was demonstrated. The textile-based OLEDs exhibited a stable operating lifetime under ambient conditions, enough mechanical durability to endure the deformation by the movement of humans, and washability for maintaining its optoelectronic properties even in water condition such as rain, sweat, or washing. In this study, the main technology used to realize this textile-based OLED was multi-functional near-room-temperature encapsulation. The outstanding impermeability of TiO2 film deposited at near-room-temperature was demonstrated. The internal residual stress in the encapsulation layer was controlled, and the device was capped by highly cross-linked hydrophobic polymer film, providing a highly impermeable, mechanically flexible, and waterproof encapsulation.

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