Phase Equilibria in the Sn-Rich Corner of the Sn–Cu–Ni Ternary Alloy System at 240 °C

2005 ◽  
Vol 20 (11) ◽  
pp. 3118-3124 ◽  
Author(s):  
Chia-Ying Li ◽  
Jenq-Gong Duh
Keyword(s):  
Flip Chip ◽  
Alloy System ◽  
Phase Region ◽  
Interfacial Reactions ◽  
X Ray Diffraction ◽  
Ternary Region ◽  
Chip Technology ◽  
Backscattered Electron ◽  
Equilibrium Phases ◽  
Electron Imaging

The interfacial reactions between solders and under bump metallization (UBM) have been of great interest recently in flip chip technology. Intermetallic compounds (IMCs), i.e., (Cu,Ni)6Sn5 and (Ni,Cu)3Sn4, usually formed between solders and UBM. To fully understand the interfacial reactions and phase transformation phenomenon, a suitable phase diagram concerning solders, IMCs, and UBM materials is required. In particular, a Sn-rich phase region in the Sn–Cu–Ni ternary diagram is very critical in determining the concentration tendency of x and y values in (Ni1−x,Cux)3Sn4 and (Cu1−y,Niy)6Sn5 compounds. In this study, ternary Sn–Cu–Ni alloys were prepared and annealed at 240 °C. Three equilibrium phases, Sn, Ni3Sn4, and Cu6Sn5, were identified by x-ray diffraction analysis and also showed in backscattered electron imaging. Using electron probe microanalysis quantitative analysis, three acme compositions of the ternary region in the Sn–Cu–Ni isotherm near the Sn-rich corner were determined as 98.5 at.% Sn, (Ni0.80, Cu0.20)3Sn4 and (Cu0.59,Ni0.41)6Sn5. In addition, the solubility of Cu and Ni in (Ni,Cu)3Sn4 and (Cu,Ni)6Sn5 compounds was evaluated. Finally, the isothermal section of the ternary Sn–Cu–Ni system at 240 °C was proposed on the basis of experimental results in this study.

scholarly journals EFFECTS OF METAKAOLIN ON COMPRESSIVE STRENGTH AND PERMEABILITY PROPERTIES OF PERVIOUS CEMENT CONCRETE

2019 ◽  
Vol 81 (5) ◽  
Author(s):  
Steve W. M. Supit ◽  
Romario W. Pandei
Keyword(s):  
Compressive Strength ◽  
Cement Composite ◽  
Infiltration Rate ◽  
Pervious Concrete ◽  
Concrete Sample ◽  
X Ray Diffraction ◽  
Interfacial Bond ◽  
Cement Concrete ◽  
Backscattered Electron ◽  
Electron Imaging

This paper presents the experimental results on the effect of metakaolin (MK) as a replacement of cement in pervious cement concrete based on compressive strength, void ratio and permeability test. Metakaolin was used to replace Portland Cement Composite (PCC) in pervious concrete by 10% (by wt.). The results show that pervious concrete sample containing 10% metakaolin with 1% superplasticizer exhibited 4 times higher compressive strength at 7 days when compared to normal cement concrete. In addition, the continuous voids of 10%MK concrete sample was found higher than PCC only, indicating the effectiveness of metakaolin in improving the interfacial bond of the binders due to micro-filler effect of metakaolin and the additional CSH gel formation. The continuous voids of pervious concrete with 10% MK is 17%, which is higher than the percentage of continuous voids in normal pervious concrete. This finding is also supported by the infiltration rate of concrete samples. Furthermore, the microstructure analysis through Backscattered Electron Imaging and X-Ray Diffraction reported denser matrix and CH reduction in polished paste samples due to 10%MK addition.

Characterization of the ternary phase at the Sn/Ni–V joint

2008 ◽  
Vol 23 (10) ◽  
pp. 2743-2748 ◽  
Author(s):  
Chih-chi Chen ◽  
Sinn-wen Chen ◽  
Chih-horng Chang
Keyword(s):  
Activation Energy ◽  
Amorphous Phase ◽  
Ternary Phase ◽  
Flip Chip ◽  
Interfacial Reactions ◽  
Fast Diffusion ◽  
Chip Technology ◽  
Primary Element ◽  
T Phase

Ni–7 wt% V diffusion barrier is commonly used in flip chip technology, and Sn is the primary element of all commercial electronic solders. Different from the interfacial reactions in the Sn/Ni couples, a ternary T phase is formed in the Sn/Ni–7 wt% V couples reacted at temperatures lower than 350 °C. The T phase is a mixture of an amorphous phase and the Ni3Sn4 phase with grains about 50 nm in size. The amorphous phase is composed mainly of Sn and V atoms, and it is formed due to the fast diffusion of Sn and relative immobility of V. Activation energy of the T phase formation is 16.5 kJ/mol, which is approximately 50% of that of the Ni3Sn4 phase determined from the Sn/Ni interfacial reactions. The T phase is no longer formed and the reaction product is the Ni3Sn4 phase in the Sn/Ni–7 wt% V couples reacted at temperatures higher than 350 °C.

Phase Stability of the Al-Cu-Co Decagonal Phase Under Conventional Solidification

2009 ◽  
Vol 1242 ◽  
Author(s):  
J.O. Téllez-Vázquez ◽  
C. Patiño-Carachure ◽  
A. Bedolla-Jacuinde ◽  
E. García-De León ◽  
R. Pérez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Structural Model ◽  
Alloy System ◽  
Phase Region ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Decagonal Phase ◽  
Transmission Electron ◽  
Thermal Stability Of

ABSTRACTAl65Cu15Co20 and Al67Cu13Co20 (% at.) alloys with composition near to the quasicrystalline decagonal phase was produced by melting in an induction furnace and solidified at room temperature. The structural characterization was carried out by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). For the structural model of decagonal quasicrsytals, it is important to know which crystalline phases have a structural relationship on the formation and decomposition of this type of phases. In the present investigation, the decagonal phase usually coexist with small amounts of the Al(Cu,Co) cubic phase of B2 type. Then, the quasicrystalline (QC) phase is outside of a single-phase region under equilibrium conditions at room temperature. DSC and TGA techniques showed the thermal stability of the alloy system up to 1000 °C.

scholarly journals Permeable Nanomontmorillonite and Fibre Reinforced Cementitious Binders

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3245 ◽  
Author(s):  
Styliani Papatzani ◽  
Sotirios Grammatikos ◽  
Kevin Paine
Keyword(s):  
Mercury Intrusion Porosimetry ◽  
Pozzolanic Reaction ◽  
Particle Packing ◽  
X Ray Diffraction ◽  
Viable Option ◽  
Backscattered Electron Imaging ◽  
X Ray ◽  
Different Types ◽  
Backscattered Electron ◽  
Electron Imaging

Clinker reduction in cementitious binders is of paramount importance today, and nanotechnology has extended permissible limits. In the present study, a reference binder consisting of 60% Portland cement, 20% limestone, 20% fly ash, 3% polyvinyl alcohol (PVA) fibres and 2% superplasticizer is optimized with three different types of nano-montmorillonite (nMt) dispersions; two organomodified ones and an inorganic one at different proportions (0.5% to 4%). Flexural strength, measured on day 7, 28, 56 and 90, was improved after day 28 with the addition of inorganic nMt. Thermal gravimetric analyses carried out on day 7, 28, 56 and 90 coupled with x-ray diffraction (at day 28) showed a distinctively enhanced pozzolanic reaction. Backscattered electron imaging confirmed changes in the microstructure. Late age relative density measurements of the nMt cementitious nanocomposites showed higher values than these of the reference paste, which can be attributed to better particle packing. Mercury intrusion porosimetry measurements give support to the optimal nMt dosage, being 1% by total mass of binder and water impermeability tests (modified with BS EN 492:2012) suggest that inorganic nMt can be a viable option material where permeability constitutes a prerequisite. Suggestions for further activation of the nMt-fibre reinforced cementitious nanocomposites were also made.

Capturing Defects in Flip-Chip CMOS Devices Using Backside EBAC Technique and SEM Microscopy

2016 ◽  
Author(s):  
Yuanjing (Jane) Li ◽  
John Aguada ◽  
Jiafang Lu ◽  
Jessica Yang ◽  
Roy Ng ◽  
...  
Keyword(s):  
Graphics Processing Units ◽  
Flip Chip ◽  
Bulk Silicon ◽  
Backscattered Electron Imaging ◽  
Visual Defects ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
Graphics Processing ◽  
20 Nm ◽  
Silicon Cmos

Abstract This paper presents backside physical failure analysis methods for capturing anomalies and defects in advanced flip-chip packaged, bulk silicon CMOS devices. Sample preparation involves chemically removing all the silicon, including the diffusions, to expose the source/drain contact silicide and the gate of the transistors from the backside. Scanning Electron Microscopy (SEM) is used to form high resolution secondary and/or backscattered electron images of the transistor structures on and beneath the exposed surface. If no visual defects/anomalies are found at the transistor level, the Electron Beam Absorbed Current (EBAC) technique is used to isolate short/open defects in the interconnect metallization layers by landing nano-probe(s) on a transistor’s source/drain silicide or on the gate. Using the combination of secondary and backscattered electron imaging and backside EBAC thus allows defects residing in either the transistors or the metal nets to be found. Case studies from 20 nm technology node graphics processing units (GPU) are presented to demonstrate the effectiveness of this approach.

scholarly journals Preparation of Novel Al-Er Master Alloys in Chloride-Fluoride Melt

2018 ◽  
Vol 918 ◽  
pp. 21-27 ◽  
Author(s):  
Yaroslav Igorevich Kosov ◽  
Vladimir Yuryevich Bazhin
Keyword(s):  
Master Alloy ◽  
Eutectic Reaction ◽  
The Novel ◽  
X Ray Diffraction ◽  
Metallothermic Reduction ◽  
Master Alloys ◽  
Backscattered Electron ◽  
The Cost ◽  
Electron Imaging

A novel Al-Er master alloy has been prepared through in situ metallothermic reactions of NaErF4 and aluminium melts. The compound NaErF4 is formed as a result of the interaction of NaF and ErF3 in the melt medium KCl. The metallothermic reactions produce erbium, which through low solubility in molten aluminium and forms intermetallic compound Al3Er. The microstructures of the Al-Er master alloy with different contents of the alloying metal has been investigated. The results showed that the Al-Er master alloy mainly consisted of phases of α-Al and Al3Er, that confirmed by the results of X-ray diffraction. Backscattered electron imaging of the Al-Er master alloy under a scanning electron microscope (SEM) revealed the presence of phase Al3Er, which crystallized in the eutectic composition [Al+Al3Er]. The observed microstructure is explained according to the eutectic reaction in an Al-Er phase diagram. The preparation of Al-Er master alloy by the metallothermic reduction method will allow to reduce energy consumption for master alloy production and to reduce the cost of aluminium alloys alloyed with Er through the novel master alloy.

Differential REE uptake by sector growth of monazite

1999 ◽  
Vol 63 (6) ◽  
pp. 813-828 ◽  
Author(s):  
G. Cressey ◽  
F. Wall ◽  
B. A. Cressey
Keyword(s):  
Single Crystal ◽  
Microprobe Analysis ◽  
X Ray Diffraction ◽  
Backscattered Electron Imaging ◽  
X Ray ◽  
Backscattered Electron ◽  
Kink Site ◽  
Electron Imaging ◽  
The Relationship

AbstractMonazite-(Ce) from a dolomite carbonatite at Kangankunde, Malawi, is sector-zoned with variation in La2O3 of up to 6.0 wt.% and in Nd2O3 of up to 3.9 wt.% between sectors. Single crystal X-ray diffraction, backscattered electron imaging and microprobe analysis have been used to establish the relationship between the morphology and sector chemistry of this low-Th monazite, (Ce,La,Nd)PO4. Uptake of La by {011} sector surfaces is enhanced relative to that of and {100} sectors; Ce shows no partitioning differences; and uptake of Nd is more easily facilitated on and {100} surfaces relative to {011}. There appears to be a distinct relationship between the size of the REE ion and the probability of uptake via the different growth surfaces. Interpretation of this uptake behaviour, based on theories involving ‘protosites’, involves an investigation of the possible kink site geometries at edge-steps during growth. Part-formed kink sites with small entrance sizes are calculated to occur with higher frequency on relative to {011}, and this correlates with an increase in the smaller-sized REE (Nd) uptake by growth surfaces. The overall morphology and sector growth is suggested to be a function of uptake chemistry.

Microstructure of Magnesium-Aluminum Metal Matrix Composites Reinforced with 2wt.% SiC Particles

2011 ◽  
Vol 413 ◽  
pp. 207-212
Author(s):  
Run Lan Zhang ◽  
Xiang Rong Liu ◽  
Tan Wei Zhou ◽  
Jian Li Yang
Keyword(s):  
Optical Microscope ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aluminum Metal ◽  
Sic Particles ◽  
The Matrix ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
Aluminum Metal Matrix Composites

SiCp/Mg-Al composites with 5μm 2wt.% SiC particles as reinforcement were prepared under the protection of inorganic flux. The microstructures, textures and components of the composites were investigated using optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD) and backscattered electron imaging (BSE). The results indicate that SiC particles are mainly distributed along grain boundaries, retarding grain growth and conducing to the refinement of the matrix. Interfacial reaction can occur between SiCp and Mg but not between SiCp and Al. There are α-Mg and β-Mg17Al12 phases, γ-MgAl phase, α-Al and β-Al3Mg2 phases in SiCp/Mg-Al composites with the Mg/Al ratio of 4/1, 1/1, 1/4 respectively.

Remarks on the application of backscattered electron imaging (BEI) to the scanning electron microscopy (SEM) of biological structures

1983 ◽  
Vol 41 ◽  
pp. 484-487
Author(s):  
Etienne de Harven
Keyword(s):  
High Resolution ◽  
Incident Beam ◽  
Spot Size ◽  
Primary Electron ◽  
Critical Point Drying ◽  
Cell Shapes ◽  
High Resolution Images ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
Scanning Electron

Biological ultrastructures have been extensively studied with the scanning electron microscope (SEM) for the past 12 years mainly because this instrument offers accurate and reproducible high resolution images of cell shapes, provided the cells are dried in ways which will spare them the damage which would be caused by air drying. This can be achieved by several techniques among which the critical point drying technique of T. Anderson has been, by far, the most reproducibly successful. Many biologists, however, have been interpreting SEM micrographs in terms of an exclusive secondary electron imaging (SEI) process in which the resolution is primarily limited by the spot size of the primary incident beam. in fact, this is not the case since it appears that high resolution, even on uncoated samples, is probably compromised by the emission of secondary electrons of much more complex origin.When an incident primary electron beam interacts with the surface of most biological samples, a large percentage of the electrons penetrate below the surface of the exposed cells.

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