共查询到20条相似文献,搜索用时 15 毫秒
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采用铺展面积法研究了Sn-3.0Ag-0.5Cu无铅钎料在不同温度下的润湿性能,同时探讨了150℃等温时效对Sn-3.0Ag-0.5Cu/Cu焊点界面组织及力学性能的影响。结果表明,随着钎焊温度的升高,Sn-3.0Ag-0.5Cu钎料的润湿性能明显增加。焊后钎料/Cu界面处对应的金属间化合物为Cu6Sn5相,经150℃时效,界面层的形貌由原来的齿状逐渐转化为层状,且厚度随着时效时间的增加而增加。发现界面层金属间化合物厚度与时效时间的二次方根成线性关系。对焊点在时效过程中的力学性能进行分析,发现Sn3.0Ag0.5Cu/Cu焊点的力学性能随着时效时间的增加逐渐降低,时效初期,焊点的力学性能下降较快,后期趋于平缓。 相似文献
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Sang-Su Ha Jong-Woong Kim Jeong-Won Yoon Sang-Ok Ha Seung-Boo Jung 《Journal of Electronic Materials》2009,38(1):70-77
The electromigration of conventional Sn-37Pb and Pb-free Sn-3.0Ag-0.5Cu (in wt.%) solder bumps was investigated with a high
current density of 2.5 × 104 A/cm2 at 423 K using flip-chip specimens comprised of an upper Si chip and a lower bismaleimide triazine (BT) substrate. Electromigration
failure of the Sn-37Pb and Sn-3.0Ag-0.5Cu solder bumps occurred with complete consumption of electroless Ni immersion Au (ENIG)
underbump metallization (UBM) and void formation at the cathode side of the solder bump. Finite element analysis and computational
simulations indicated high current crowding of electrons in the patterned Cu on the Si chip side, whereas the solder bumps
and Cu line of the BT substrate had a relatively low density of flowing electrons. These findings were confirmed by the experimental
results. The electromigration reliability of the Sn-3.0Ag-0.5Cu solder joint was superior to that of Sn-37Pb. 相似文献
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Cu under bump metallurgy (UBM) has been widely used in flip-chip technology. The major disadvantages of Cu UBM are fast consumption
of copper, rapid growth of intermetallic compounds (IMCs), and easy formation of Kirkendall voids. In this study we added
two different contents of Mn (2 at.% and 10 at.%) to Cu UBM by sputtering to modify the conventional Cu metallization. For
the higher Mn concentration in the Cu-Mn UBM, a new Sn-rich phase formed between Cu6Sn5 and the Cu-Mn UBM, and cracks formed after aging. For the lower Mn concentration, growth of Cu3Sn and Kirkendall voids was significantly suppressed after thermal aging. Kinetic analysis and x-ray elemental mapping provided
evidence that Mn diffusion into Cu3Sn slowed diffusion of Cu in the Cu3Sn layer. The Mn-enriched Cu3Sn layer may serve as a diffusion barrier to reduce the interfacial reaction rate and Kirkendall void formation. These results
suggest that Cu-Mn UBM with low Mn concentration is beneficial in terms of retarding Cu pad consumption in solder joints. 相似文献
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Gayatri Cuddalorepatta Maureen Williams Abhijit Dasgupta 《Journal of Electronic Materials》2010,39(10):2292-2309
The viscoplastic behavior of as-fabricated, undamaged, microscale Sn-3.0 Ag-0.5Cu (SAC305) Pb-free solder is investigated
and compared with that of eutectic Sn-37Pb solder and near-eutectic Sn-3.8Ag-0.7Cu (SAC387) solder from prior studies. Creep
measurements of microscale SAC305 solder shear specimens show significant piece-to-piece variability under identical loading.
Orientation imaging microscopy reveals that these specimens contain only a few, highly anisotropic Sn grains across the entire
joint. For the studied loads, the coarse-grained Sn microstructure has a more significant impact on the scatter in primary
creep compared to that in the secondary creep. The observed lack of statistical homogeneity (microstructure) and joint-dependent
mechanical behavior of microscale SAC305 joints are consistent with those observed for functional microelectronics interconnects.
Compared with SAC305 joints, microscale Sn-37Pb shear specimens exhibit more homogenous behavior and microstructure with a
large number of small Sn (and Pb) grains. Creep damage in the Pb-free joint is predominantly concentrated at highly misoriented
Sn grain boundaries. The coarse-grained Sn microstructure recrystallizes into new grains with high misorientation angles under
creep loading. In spite of the observed joint-dependent behavior, as-fabricated SAC305 is significantly more creep resistant
than Sn-37Pb solder and slightly less creep resistant than near-eutectic SAC387 solder. Average model constants for primary
and secondary creep of SAC305 are presented. Since the viscoplastic measurements are averaged over a wide range of grain configurations,
the creep model constants represent the effective continuum behavior in an average sense. The average secondary creep behavior
suggests that the dominant creep mechanism is dislocation climb assisted by dislocation pipe diffusion. 相似文献
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Mysore K. Subbarayan G. Gupta V. Ron Zhang 《Electronics Packaging Manufacturing, IEEE Transactions on》2009,32(4):221-232
We describe double-lap shear experiments on Sn3.0Ag0.5Cu solder alloy, from which fits to Anand's viscoplastic constitutive model, power-law creep model, and to time-hardening primary-secondary creep model are derived. Results of monotonic tests for strain rates ranging from 4.02E-6 to 2.40E-3 s-1, and creep response at stress levels ranging from 19.5 to 45.6 MPa are reported. Both types of tests were conducted at temperatures of 25degC, 75degC , and 125degC. Following an earlier study where Anand model and time hardening creep parameters for Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu solder alloys were reported, here we report power law model parameters so as to enable a comparison between all three alloys. Primary creep in Sn3.0Ag0.5Cu solder alloy is shown to be significant and are considered in addition to secondary creep and monotonic behavior. Aging influence on behavior is also shown to be significant. On the basis of experimental data, the following four aspects are discussed: 1) difference between testing on bulk versus joint specimen; 2) consistency between the creep and monotonic behaviors; 3) comparison against behaviors of Sn1.0Ag0.5Cu and Sn3.8Ag0.7Cu alloys as well as aganist Sn40Pb, 62Sn36Pb2Ag and 96.5Sn3.5Ag alloys; and 4) comparison of Sn3.0Ag0.5Cu and Sn3.8Ag0.7Cu relative to their aging response. 相似文献
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Nanoparticles of the Lead-free Solder Alloy Sn-3.0Ag-0.5Cu with Large Melting Temperature Depression
Chang Dong Zou Yu Lai Gao Bin Yang Xin Zhi Xia Qi Jie Zhai Cristina Andersson Johan Liu 《Journal of Electronic Materials》2009,38(2):351-355
Due to the toxicity of lead (Pb), Pb-containing solder alloys are being phased out from the electronics industry. This has
lead to the development and implementation of lead-free solders. Being an environmentally compatible material, the lead-free
Sn-3.0Ag-0.5Cu (wt.%) solder alloy is considered to be one of the most promising alternatives to replace the traditionally
used Sn-Pb solders. This alloy composition possesses, however, some weaknesses, mainly as a result of its higher melting temperature
compared with the Sn-Pb solders. A possible way to decrease the melting temperature of a solder alloy is to decrease the alloy
particle size down to the nanometer range. The melting temperature of Sn-3.0Ag-0.5Cu lead-free solder alloy, both as bulk
and nanoparticles, was investigated. The nanoparticles were manufactured using the self-developed consumable-electrode direct
current arc (CDCA) technique. The melting temperature of the nanoparticles, with an average size of 30 nm, was found to be
213.9°C, which is approximately 10°C lower than that of the bulk alloy. The developed CDCA technique is therefore a promising
method to manufacture nanometer-sized solder alloy particles with lower melting temperature compared with the bulk alloy. 相似文献
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X. P. Li J. M. Xia M. B. Zhou X. Ma X. P. Zhang 《Journal of Electronic Materials》2011,40(12):2425-2435
The standoff height of ball grid array (BGA) structure solder joints has a significant influence on the formation and growth
of interfacial intermetallic compounds (IMC). The results show that the thickness of the IMC layer at the solder/Cu interface
of BGA structure Cu/Sn-3.0Ag-0.5Cu/Cu joints increases with decreasing standoff height after reflowing. The growth behavior
of the total IMC layer is controlled by a diffusion process with the growth rate increasing with standoff height. Both the
standoff height and isothermal aging time greatly influence the shear behavior of joints, the shear strength of which shows
a parabolic trend with increasing standoff height, while the nominal shear strain decreases monotonically with increasing
standoff height. The fracture location of BGA structure joints changed from the middle of the solder matrix to near the interface
when the standoff height was increased. After undergoing isothermal aging at 125°C, the fracture mechanism of solder joints
changed from ductile fracture to the mixed mode of brittle and ductile fracture with increasing standoff height. 相似文献
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Yun-Hwan Jo Joo Won Lee Sun-Kyoung Seo Hyuck Mo Lee Hun Han Dong Chun Lee 《Journal of Electronic Materials》2008,37(1):110-117
A combination solder of Sn-3.0Ag-0.5Cu (numbers are all in weight percent unless specified otherwise) wrapped by Sn-57Bi-1Ag
was tested for application to three-dimensional (3-D) multistack packaging. The experimental variables controlled were the
reflow peak temperatures (170, 185, 200, and 230°C), the reflow cycles (up to four times), and the mask which controls the
amount of Sn-57Bi-1Ag solder paste (two sizes). We demonstrate and evaluate the combination solder structure, focusing on
microstructural changes and the shear strength. The degree of mixing in the combination solder, which is enhanced by an increase
in the reflow peak temperature, is independent of the number of reflow cycles. The ball shear strength and the lab shear strength
both increased with increases in the reflow peak temperatures. This behavior is explained by the amount of the brittle Bi
phase that constitutes the eutectic Sn-Bi phase. 相似文献
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The aim of this study is to evaluate the corrosion behavior of Sn-3.0Ag-0.5Cu (SAC305) lead-free solder joint using salt spray test. The presence of Cu pad accelerates the dissolution of Sn from solder joints into corrosive medium because of galvanic corrosion mechanism. So, the solder joint was easily corroded in corrosive environment than SAC305 solder bar. During salt spray test, pitting corrosion begin from the solidification cracks in the solder joints, which will lead to a decrease of the reliability of solder joints and shorten the life of electronic devices. 相似文献
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Potentiodynamic polarization techniques were employed in the present study to investigate the corrosion behavior of Pb-free Sn-1Ag-0.5Cu-XNi solder alloys in 3.5% NaCl solution. Polarization studies indicated that an increase in Ni content from 0.05 wt.% to 1 wt.% in the solder alloy shifted the corrosion potential (E corr) towards more negative values and increased the linear polarization resistance. Increased addition of Ni to 1 wt.% resulted in significant increase in the concentration of both Sn and Ni oxides on the outer surface. Secondary-ion mass spectrometry and Auger depth profile analysis revealed that oxides of tin contributed primarily towards the formation of the passive film on the surface of the solder alloys containing 0.05 wt.% and 1 wt.% Ni. Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX) established the formation of a Sn whisker near the passive region of the solder alloy obtained from the polarization curves. The formation of Sn whiskers was due to the buildup of compressive stress generated by the increase in the volume of the oxides of Sn and Ni formed on the outer surface. The presence of Cl? was responsible for the breakdown of the passive film, and significant pitting corrosion in the form of distinct pits was noticed in Sn-1Ag-0.5Cu-0.5Ni solder alloy after the polarization experiment. 相似文献
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Ti/Ni(V)/Cu underbump metallization (UBM) is widely used in flip-chip technology today. The advantages of Ti/Ni(V)/Cu UBM
are a low reaction rate with solder and the lack of a magnetic effect during sputtering. Sn atoms diffuse into the Ni(V) layer
to form a Sn-rich phase, the so-called Sn-patch, during reflow and aging. In this study, the relationship between interfacial
reaction and mechanical properties of the solder joints with Ti/Ni(V)/Cu UBM was evaluated. Sn-3.0Ag-0.5Cu solder was reflowed
on sputtered Ti/Ni(V)/Cu UBM, and then the reflowed samples were aged at 125°C and 200°C, respectively. (Cu,Ni)6Sn5 was formed and grew gradually at the interface of the solder joints during aging at 125°C. The Sn-patch replaced the Ni(V)
layer, and (Ni,Cu)3Sn4 was thus formed between (Cu,Ni)6Sn5 and the Sn-patch at 200°C. The Sn-patch, composed of Ni and V2Sn3 after reflow, was transformed to V2Sn3 and amorphous Sn during aging. Shear and pull tests were applied to evaluate the solder joints under various heat treatments.
The shear force of the solder joints remained at 421 mN, yet the pull force decreased after aging at 125°C. Both the shear
and pull forces of the solder joints decreased during aging at 200°C. The effects of aging temperature on the mechanical properties
of solder joint were investigated and discussed. 相似文献
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Jae-Myeong Kim Myeong-Hyeok Jeong Sehoon Yoo Young-Bae Park 《Journal of Electronic Materials》2012,41(4):791-799
The effects of surface finishes on the in situ interfacial reaction characteristics of ball grid array (BGA) Sn-3.0Ag-0.5Cu lead-free solder bumps were investigated under
annealing and electromigration (EM) test conditions of 130°C to 175°C with 5.0 × 103 A/cm2. During reflow and annealing, (Cu,Ni)6Sn5 intermetallic compound (IMC) formed at the interface of electroless nickel immersion gold (ENIG) finish. In the case of both
immersion Sn and organic solderability preservative (OSP) finishes, Cu6Sn5 and Cu3Sn IMCs formed. Overall, the IMC growth velocity of ENIG was much lower than that of the other finishes. The activation energies
of total IMCs were found to be 0.52 eV for ENIG, 0.78 eV for immersion Sn, and 0.72 eV for OSP. The ENIG finish appeared to
present an effective diffusion barrier between the Cu substrate and the solder, which leads to better EM reliability in comparison
with Cu-based pad systems. The failure mechanisms were explored in detail via in situ EM tests. 相似文献
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F. X. Che W. H. Zhu Edith S. W. Poh X. R. Zhang Xiaowu Zhang T. C. Chai S. Gao 《Journal of Electronic Materials》2011,40(3):344-354
In this work, tensile creep tests for Sn-1.0Ag-0.5Cu-0.02Ni solder have been conducted at various temperatures and stress
levels to determine its creep properties. The effects of stress level and temperature on creep strain rate were investigated.
Creep constitutive models (such as the simple power-law model, hyperbolic sine model, double power-law model, and exponential
model) have been reviewed, and the material constants of each model have been determined based on experimental results. The
stress exponent and creep activation energy have been studied and compared with other researchers’ results. These four creep
constitutive models established in this paper were then implemented into a user-defined subroutine in the ANSYS™ finite-element
analysis software to investigate the creep behavior of Sn-1.0Ag-0.5Cu-0.02Ni solder joints of thin fine-pitch ball grid array
(TFBGA) packages for the purpose of model comparison and application. Similar simulation results of creep strain and creep
strain energy density were achieved when using the different creep constitutive models, indicating that the creep models are
consistent and accurate. 相似文献
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Young Min Kim Hee-Ra Roh Sungtae Kim Young-Ho Kim 《Journal of Electronic Materials》2010,39(12):2504-2512
The growth kinetics of an intermetallic compound (IMC) layer formed between Sn-3.5Ag-0.5Cu (SAC) solders and Cu-Zn alloy substrates
was investigated for samples aged at different temperatures. Scallop-shaped Cu6Sn5 formed after soldering by dipping Cu or Cu-10 wt.%Zn wires into the molten solder at 260°C. Isothermal aging was performed
at 120°C, 150°C, and 180°C for up to 2000 h. During the aging process, the morphology of Cu6Sn5 changed to a planar type in both specimens. Typical bilayer of Cu6Sn5 and Cu3Sn and numerous microvoids were formed at the SAC/Cu interfaces after aging, while Cu3Sn and microvoids were not observed at the SAC/Cu-Zn interfaces. IMC growth on the Cu substrate was controlled by volume diffusion
in all conditions. In contrast, IMC growth on Cu-Zn specimens was controlled by interfacial reaction for a short aging time
and volume diffusion kinetics for a long aging time. The growth rate of IMCs on Cu-Zn substrates was much slower due to the
larger activation energy and the lower layer growth coefficient for the growth of Cu-Sn IMCs. This effect was more prominent
at higher aging temperatures. 相似文献