Stability of channels at a scalloplike Cu6Sn5 layer in solder interconnections

2001 ◽  
Vol 16 (5) ◽  
pp. 1227-1230 ◽  
Author(s):  
Jong-Hyun Lee ◽  
Jong-Hwan Park ◽  
Yong-Ho Lee ◽  
Yong-Seog Kim ◽  
Dong Hyuk Shin
Keyword(s):  
Growth Rate ◽  
Grain Boundaries ◽  
Thermodynamic Stability ◽  
Direct Evidence ◽  
Electron Backscattered Diffraction ◽  
Reflow Soldering ◽  
Cu Substrate ◽  
Cu6sn5 Layer ◽  
Penetration Behavior ◽  
Orientational Relationship

The thermodynamic stability of the solder channels at a scalloplike Cu6Sn5 layer formed between Sn-containing solders and Cu substrate was evaluated by studying the penetration behavior of the liquid solders into the grain boundaries of a Cu6Sn5 substrate. The orientational relationship between the grains of the Cu6Sn5 layer formed during reflow soldering was also analyzed using the electron backscattered diffraction technique. The results showed that liquid solders penetrate into the grain boundaries at an order of faster speed than the growth rate of the layer, which provided a direct evidence of thermodynamic stability of the channel.

Enhanced Growth Kinetics of Intermetallic Compounds between Bi-Containing Sn-3.5Ag Solders and Cu Substrate during Aging

2005 ◽  
Vol 475-479 ◽  
pp. 2627-2630
Author(s):  
Soon Tae Kim ◽  
Joo Youl Huh
Keyword(s):  
Growth Rate ◽  
Intermetallic Compounds ◽  
Solder Alloy ◽  
Interfacial Reaction ◽  
Growth Kinetics ◽  
Cu Substrate ◽  
Reaction Barrier ◽  
Cu3sn Layer ◽  
Cu6sn5 Layer ◽  
Kinetics Of

The effect of adding Bi to a eutectic Sn-3.5Ag solder alloy on the growth kinetics of the intermetallic compounds (IMCs) in solder/Cu joints was examined at the aging temperatures of 130°C, 150°C and 180°C. At 150°C and 180°C, the growth rate of the Cu6Sn5 layer was significantly enhanced, but that of the Cu3Sn layer was rather reduced with increasing Bi content up to 12 wt.%. At 130°C, however, both the η and ε layers appeared to grow faster as the Bi content in the solder was increased to 12 wt.%. These results suggest that the accumulation of Bi ahead of the Cu6Sn5 layers can affect not only the interfacial reaction barrier but also the local thermodynamics at the interface between the Cu6Sn5 layer and the solder.

Unravelling transient phases during thermal oxidation of copper for dense CuO nanowire growth

CrystEngComm ◽  
2014 ◽  
Vol 16 (16) ◽  
pp. 3264-3267 ◽  
Author(s):  
Fei Wu ◽  
Yoon Myung ◽  
Parag Banerjee
Keyword(s):  
Raman Spectroscopy ◽  
Grain Boundaries ◽  
Thermal Oxidation ◽  
High Purity ◽  
Direct Evidence ◽  
Nanowire Growth ◽  
Cupric Ion ◽  
Cuo Nanowire ◽  
Transient Phases

Direct evidence of cupric ion outdiffusion through grain boundaries during thermal oxidation of high purity Cu is obtained using Raman spectroscopy.

An Sem/Ebsd Study of Shear Bands Formation in Al-0.23%wt.Zr Alloy Deformed in Plane Strain Compression / Krystalograficzne Aspekty Formowania Sie Pasm Scinania W Stopie Al-0.23%Wag.Zr Odkształcanym W Próbie Nieswobodnego Sciskania

2013 ◽  
Vol 58 (1) ◽  
pp. 145-150 ◽  
Author(s):  
H. Paul ◽  
P. Uliasz ◽  
M. Miszczyk ◽  
W. Skuza ◽  
T. Knych
Keyword(s):  
Crystal Lattice ◽  
Grain Boundaries ◽  
Texture Evolution ◽  
Shear Bands ◽  
Shear Direction ◽  
Face Centered Cubic ◽  
Electron Backscattered Diffraction ◽  
Cubic Metals ◽  
Slip Planes ◽  
Face Centered

The crystal lattice rotations induced by shear bands formation have been examined in order to investigate the influence of grain boundaries on slip propagation and the resulting texture evolution. The issue was analysed on Al-0.23wt.%Zr alloy as a representative of face centered cubic metals with medium-to-high stacking fault energy. After solidification, the microstructure of the alloy was composed of flat, twin-oriented, large grains. The samples were cut-off from the as-cast ingot in such a way that the twinning planes were situated almost parallel to the compression plane. The samples were then deformed at 77K in channel-die up to strains of 0.69. To correlate the substructure with the slip patterns, the deformed specimens were examined by SEM equipped with a field emission gun and electron backscattered diffraction facilities. Microtexture measurements showed that strictly defined crystal lattice re-orientations occurred in the sample volumes situated within the area of the broad macroscopic shear bands (MSB), although the grains initially had quite different crystallographic orientations. Independently of the grain orientation, their crystal lattice rotated in such a way that one of the f111g slip planes became nearly parallel to the plane of maximum shear. This facilitates the slip propagation across the grain boundaries along the shear direction without any visible variation in the slip plane. A natural consequence of this rotation is the formation of specific MSB microtextures which facilitates slip propagation across grain boundaries.

Influence of cooling media in achieving grain refinement of AA2014 alloy using friction stir processing

2020 ◽  
Vol 234 (22) ◽  
pp. 4520-4534
Author(s):  
MVNV Satyanarayana ◽  
Adepu Kumar
Keyword(s):  
Grain Boundaries ◽  
Friction Stir Processing ◽  
Heat Dissipation ◽  
Electron Backscattered Diffraction ◽  
Friction Stir ◽  
Fine Grained ◽  
Fine Grained Structure ◽  
Cooling Media ◽  
Processing Zone ◽  
Friction Stir Processing Sample

The present paper studies the influence of different cooling media (water and cryogenic media) on microstructure, mechanical, and corrosion behavior of friction stir processing of AA2014. From the electron backscattered diffraction results, it was observed that the grain size in stir zone of air-cooled friction stir processing, dry ice-cooled friction stir processing, and underwater friction stir processing are 4.9 µm, 3.5 µm, and 0.9 µm respectively, and the fraction of high angle grain boundaries are more in underwater friction stir processing sample compared to other conditions. The ultra-fine grained structure (0.9 µm) was achieved in underwater friction stir processing due to uniform heat dissipation from the processing zone to the water. Mechanical properties such as hardness and strength were improved in underwater friction stir processing compared to other conditions. The fine precipitates formed in the underwater friction stir processing sample were distributed randomly at grain boundaries, and hence corrosion resistance was improved in underwater friction stir processing sample compared to other conditions.

scholarly journals Dynamic Observation of Interfacial IMC Evolution and Fracture Mechanism of Sn2.5Ag0.7Cu0.1RE/Cu Lead-Free Solder Joints during Isothermal Aging

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 831 ◽  
Author(s):  
Di Zhao ◽  
Keke Zhang ◽  
Ning Ma ◽  
Shijie Li ◽  
Chenxiang Yin ◽  
...  
Keyword(s):  
Growth Rate ◽  
Fracture Mechanism ◽  
Isothermal Aging ◽  
Solder Joints ◽  
Diffusion Mechanism ◽  
Bulk Diffusion ◽  
Cu Substrate ◽  
Dynamic Observation ◽  
Free Solder ◽  
The Relationship

Dynamic observation of the microstructure evolution of Sn2.5Ag0.7Cu0.1RE/Cu solder joints and the relationship between the interfacial intermetallic compound (IMC) and the mechanical properties of the solder joints were investigated during isothermal aging. The results showed that the original single scallop-type Cu6Sn5 IMC gradually evolved into a planar double-layer IMC consisting of Cu6Sn5 and Cu3Sn IMCs with isothermal aging. In particular, the Cu3Sn IMC grew towards the Cu substrate and the solder seam sides; growth toward the Cu substrate side was dominant during the isothermal aging process. The growth of Cu3Sn IMC depended on the accumulated time at a certain temperature, where the growth rate of Cu3Sn was higher than that of Cu6Sn5. Additionally, the growth of the interfacial IMC was mainly controlled by bulk diffusion mechanism, where the activation energies of Cu6Sn5 and Cu3Sn were 74.7 and 86.6 kJ/mol, respectively. The growth rate of Cu3Sn was slightly faster than that of Cu6Sn5 during isothermal aging. With increasing isothermal aging time, the shear strength of the solder joints decreased and showed a linear relationship with the thickness of Cu3Sn. The fracture mechanism of the solder joints changed from ductile fracture to brittle fracture, and the fracture pathway transferred from the solder seam to the interfacial IMC layer.

X-Ray Reflectivity Study of Single- and Bicrystals of Gold

1990 ◽  
Vol 208 ◽  
Author(s):  
M. R. Fitzsimmons ◽  
E. Burkel ◽  
J. Peisl
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Diffuse Scattering ◽  
Direct Evidence ◽  
X Ray ◽  
Specular Reflectivity ◽  
Boundary Measurements

ABSTRACTX-ray reflectivity techniques have been used to characterize the surfaces of 0.4µm thick Au films epitaxially grown on single-crystals of NaCl. Measurements of both the specular and non-specular reflectivity suggest that the Au surface is very rough. The nonspecular reflectivity provides valuable information about the correlation of the heights at different points on the surface. The first in situ reflectivity study of the formation and destruction of a grain boundary shows direct evidence for the existence of diffuse scattering from the grain boundary. Measurements of several [0011 twist grain boundaries suggest that the roughness and texture of an interface depends upon the geometrical orientation of the surrounding substrates.

Grain Boundary-Dependent Selection Criteria for Nucleation of Gamma-Massive Grains in TiAl-Based Alloys

2010 ◽  
Vol 654-656 ◽  
pp. 2338-2341 ◽  
Author(s):  
A. Sankaran ◽  
Emmanuel Bouzy ◽  
Matthew R. Barnett ◽  
Alain Hazotte
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Selection Criteria ◽  
Three Dimensional ◽  
Massive Transformation ◽  
Three Dimensions ◽  
Variant Selection ◽  
Electron Backscattered Diffraction ◽  
Resolution Electron ◽  
Nucleation Mechanisms

Rapid cooling of TiAl-based alloy from α phase (disordered hexagonal, A3) generates  phase (ordered tetragonal, L1o) grains through massive transformation nucleating mostly over the α/α grain boundaries. This current work deals with the identification and the validation of different nucleation mechanisms during  massive transformation in TiAl-based alloys. Special attention has been given to the variant selection criteria for the nucleation of the massive structures along different types of α/α grain boundaries. The  massive domains formed along the grain boundaries were analysed using high resolution electron backscattered diffraction (EBSD). Statistical studies were made on different nucleation sites and different mechanisms are proposed. Two–dimensional studies of the nucleation mechanism suggest that the minimization of the interfacial energy could be the predominant criteria during the grain boundary nucleation. In order to verify this nucleation criterion in three-dimensions, serial sections were made and EBSD maps were taken and analysed in each section. The variant selection observed during the nucleation and the growth of the  massive grains is further discussed after getting a broader view under three-dimensional investigations.

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