This document discusses a study on the effects of wire type (copper vs gold) and mold compound on the wearout reliability of semiconductor flash packages after high temperature aging and temperature cycling stress tests. Copper ball bonds were found to have better reliability than gold bonds after high temperature aging, exhibiting longer time to failure. Copper bonds also showed slightly better reliability than gold after temperature cycling. Failure analysis identified intermetallic cracking as the failure mechanism. The mold compound was also found to influence reliability, with one compound showing longer time to failure for both wire types in both stress tests compared to the other compound. In conclusion, copper wire and one of the mold compounds evaluated provided enhanced wearout reliability performance over gold wire and the other mold
Evolutions of bonding wires used in semiconductor electronics perspective ove...Chong Leong Gan
This document reviews the evolution of bonding wires used in semiconductor electronics over 25 years. It discusses gold wire bonding, which was the first wire alloy introduced and remains widely used. Challenges with gold include rising costs. Copper wire bonding was introduced as a lower-cost alternative, but faces challenges with corrosion resistance. Solutions to copper wire bonding challenges include using palladium-coated copper wires, which have demonstrated improved reliability and bondability. The document also examines the materials properties and reliability of different wire types over time.
Structural, compositional and electrochemical properties of Aluminium-Silicon...IOSR Journals
This document summarizes the structural, compositional and electrochemical properties of an Aluminium-Silicon-Chromium alloy thin film for use as an anode in lithium thin film batteries. Key points:
1) An Al-Si-Cr alloy thin film was deposited using DC magnetron sputtering. XRD and EDAX analysis confirmed the film had a nanocrystalline structure and composition matching the sputtering target.
2) Electrochemical testing showed lithium could be reversibly inserted into and removed from the Al-Si-Cr film. The film displayed higher initial capacity and better capacity retention over 50 cycles compared to pure silicon film.
3) SEM analysis indicated cycling caused
Investigation of the distribution of lead in three different combinations of ...Rautomead Limited
The main objective of this paper was to assess three leaded
brass samples (pending application with Copper Development
Association) using optical microscopy and mass
spectrometry to compare the distribution of lead. Based on
the mass spectrometry data, a great deal of variation was
not found within each of the samples based on five different
sample locations. Optical microscopy, scanning electron
microscopy and energy-dispersive X-ray spectroscopy
confirmed that the lead was homogenously distributed in
brass.
Effect of Temperature and Nickel Concentration on the Electrical and Dielectr...IJERD Editor
In this paper the effect of temperature range of 298 K to 348 K and volume filler content ф on
electrical properties of polyethylene PE filled with nickel Ni powders has been investigated .The volume
electrical resistivity
V
of such composites decreases suddenly by several orders of magnitude at a critical
volume concentration (i.e. фc=14.27 Vol.%) ,whereas the dielectric constant and the A.C electrical
conductivity AC of such composites increase suddenly at a critical volume concentration (i.e. фc=14.27
Vol.%).For volume filler content lower than percolation threshold ф<фc> фc there is increase in the value of their
resistivity, and decrease in the value of their dielectric constant and the A.C electrical conductivity AC with
increasing temperature indicating metallic-conduction.
Experimental Analysis of Mechanical Properties of Aluminum Alloy LM-4 by Vari...IRJET Journal
The document analyzes the effects of varying copper content on the mechanical properties of aluminum alloy LM-4. Five aluminum alloy samples were produced with copper content ranging from 5% to 11% using die casting. Tensile testing showed that ultimate tensile strength increased with increasing copper content, with the highest strength achieved in the 11% copper alloy. Microstructural analysis found that copper improves strength through precipitation strengthening during heat treatment.
Characteristics of Hypoeutectic Cu-Zr Alloy Rods Manufactured by Vertical Upw...Rautomead Limited
The focus in this study is therefore on applying a vertical upwards continuous casting (VUCC) mass-production
method to the pilot-scale manufacturing of Cu-Zr alloy rods. The microstructure and physical characteristics of these
VUCC rods were subsequently investigated and compared with rods produced by CMC. In addition, the wire-drawing
capability of the VUCC rods was examined, and the adaptability of the VUCC method to the mass production of
hypoeutectic Cu-Zr alloys was fully investigated.
2.
1. Introduction
2. Theoretical basics of MSHC materials creating (basics rules, materials hardening methods, alloying rules)
3. Analysis of medium strength high conductivity copper alloys (phase diagrams, requirements, properties, fabrication and exploitation properties, main applications)
Cu-Ag
Cu-Mg
Cu-Sn
Cu-Fe
Cu-Zr
Cu-Ni-Si
other elements
4. Complex comparison analysis of medium strength high conductivity copper alloys vs. copper grade ETP.
5. Trends of medium strength high conductivity copper alloys development, new applications and cost-effectiveness.
6. Conclusions
The document discusses the effects of adding strontium and silicon carbide on the mechanical properties of an aluminum alloy (LM6). Key findings include:
1) Adding 0.5 wt% strontium and 10 wt% silicon carbide improved the ultimate tensile strength and hardness of the aluminum alloy the most compared to other concentrations tested.
2) The microstructure was modified by adding strontium, changing the silicon morphology from needle-like to fibrous and increasing the amount of alpha-aluminum dendrites, leading to enhanced properties.
3) While strengths increased with the additions, the tensile strength of the composites did not increase dramatically due to weak particle-matrix interfaces. Heat
Evolutions of bonding wires used in semiconductor electronics perspective ove...Chong Leong Gan
This document reviews the evolution of bonding wires used in semiconductor electronics over 25 years. It discusses gold wire bonding, which was the first wire alloy introduced and remains widely used. Challenges with gold include rising costs. Copper wire bonding was introduced as a lower-cost alternative, but faces challenges with corrosion resistance. Solutions to copper wire bonding challenges include using palladium-coated copper wires, which have demonstrated improved reliability and bondability. The document also examines the materials properties and reliability of different wire types over time.
Structural, compositional and electrochemical properties of Aluminium-Silicon...IOSR Journals
This document summarizes the structural, compositional and electrochemical properties of an Aluminium-Silicon-Chromium alloy thin film for use as an anode in lithium thin film batteries. Key points:
1) An Al-Si-Cr alloy thin film was deposited using DC magnetron sputtering. XRD and EDAX analysis confirmed the film had a nanocrystalline structure and composition matching the sputtering target.
2) Electrochemical testing showed lithium could be reversibly inserted into and removed from the Al-Si-Cr film. The film displayed higher initial capacity and better capacity retention over 50 cycles compared to pure silicon film.
3) SEM analysis indicated cycling caused
Investigation of the distribution of lead in three different combinations of ...Rautomead Limited
The main objective of this paper was to assess three leaded
brass samples (pending application with Copper Development
Association) using optical microscopy and mass
spectrometry to compare the distribution of lead. Based on
the mass spectrometry data, a great deal of variation was
not found within each of the samples based on five different
sample locations. Optical microscopy, scanning electron
microscopy and energy-dispersive X-ray spectroscopy
confirmed that the lead was homogenously distributed in
brass.
Effect of Temperature and Nickel Concentration on the Electrical and Dielectr...IJERD Editor
In this paper the effect of temperature range of 298 K to 348 K and volume filler content ф on
electrical properties of polyethylene PE filled with nickel Ni powders has been investigated .The volume
electrical resistivity
V
of such composites decreases suddenly by several orders of magnitude at a critical
volume concentration (i.e. фc=14.27 Vol.%) ,whereas the dielectric constant and the A.C electrical
conductivity AC of such composites increase suddenly at a critical volume concentration (i.e. фc=14.27
Vol.%).For volume filler content lower than percolation threshold ф<фc> фc there is increase in the value of their
resistivity, and decrease in the value of their dielectric constant and the A.C electrical conductivity AC with
increasing temperature indicating metallic-conduction.
Experimental Analysis of Mechanical Properties of Aluminum Alloy LM-4 by Vari...IRJET Journal
The document analyzes the effects of varying copper content on the mechanical properties of aluminum alloy LM-4. Five aluminum alloy samples were produced with copper content ranging from 5% to 11% using die casting. Tensile testing showed that ultimate tensile strength increased with increasing copper content, with the highest strength achieved in the 11% copper alloy. Microstructural analysis found that copper improves strength through precipitation strengthening during heat treatment.
Characteristics of Hypoeutectic Cu-Zr Alloy Rods Manufactured by Vertical Upw...Rautomead Limited
The focus in this study is therefore on applying a vertical upwards continuous casting (VUCC) mass-production
method to the pilot-scale manufacturing of Cu-Zr alloy rods. The microstructure and physical characteristics of these
VUCC rods were subsequently investigated and compared with rods produced by CMC. In addition, the wire-drawing
capability of the VUCC rods was examined, and the adaptability of the VUCC method to the mass production of
hypoeutectic Cu-Zr alloys was fully investigated.
2.
1. Introduction
2. Theoretical basics of MSHC materials creating (basics rules, materials hardening methods, alloying rules)
3. Analysis of medium strength high conductivity copper alloys (phase diagrams, requirements, properties, fabrication and exploitation properties, main applications)
Cu-Ag
Cu-Mg
Cu-Sn
Cu-Fe
Cu-Zr
Cu-Ni-Si
other elements
4. Complex comparison analysis of medium strength high conductivity copper alloys vs. copper grade ETP.
5. Trends of medium strength high conductivity copper alloys development, new applications and cost-effectiveness.
6. Conclusions
The document discusses the effects of adding strontium and silicon carbide on the mechanical properties of an aluminum alloy (LM6). Key findings include:
1) Adding 0.5 wt% strontium and 10 wt% silicon carbide improved the ultimate tensile strength and hardness of the aluminum alloy the most compared to other concentrations tested.
2) The microstructure was modified by adding strontium, changing the silicon morphology from needle-like to fibrous and increasing the amount of alpha-aluminum dendrites, leading to enhanced properties.
3) While strengths increased with the additions, the tensile strength of the composites did not increase dramatically due to weak particle-matrix interfaces. Heat
Analysis of Al 6061-TiO2 -CNT Metal Matrix Composites Produced by Stir Castin...Dr. Amarjeet Singh
Aluminium Hybrid Composites are the new groupof
metal matrix composites (MMCs) due to their attractive
properties like high ductility, high conductivity, light weight
and high strength to weight ratio and is a response to the
dynamic ever-increasing demand of these super material in
the field of aircrafts and marines. Carbon Nanotube (CNTs)
are also known for their high strength and stiffness and their
low density which when combined together makes CNTs an
ideal reinforcement. This work briefly reviews the research
revelation of an Aluminium (Al-6061) based hybrid metal
matrix composite reinforced with CNTs and TiO2. The
Hybrid Aluminium Metal Matrix Composites (AMMCs) is
prepared with various CNTs weight percentages (0, 0.5, 1 and
1.5 wt. %) and keeping TiO2 weight percentage fixed to
1%.Stir Casting (SC) is focused in general to successfully
fabricate the MMCs. The discussion of this work revolves
around tensile test, hardness test, and Scanning Electron
Microscope (SEM) of the MMC. The mechanical properties
of the fabricated MMCs materials like tensile strength,
hardness and impact strength is found by using these
experimental methods. It has been observed that the tensile
strength of the MMCs increases in the presence of TiO2 and
CNTs and increases even more with the increase in the weight
fraction of CNTs. Same results have been obtained for
hardness and impact strength where there is an increase in
them in the presence of TiO2 and CNT and their value
increases even further with increase in weight fraction of
CNTs.
This document summarizes research on the degradation of high-temperature materials used in traditional and modern energy systems. It discusses oxidation and microstructural degradation issues affecting materials in steam generators and fossil fuel plants. It presents experimental data on oxidation kinetics of steels from laboratory tests and power plants. The document also examines challenges for higher-temperature materials in advanced fossil plants. Further, it explores using nanocrystalline alloys and graphene coatings to improve oxidation resistance of materials for solid oxide fuel cells and other applications. The research involves collaboration with multiple universities and industry partners.
The main objective of this project is to be produce copper reinforced metal matrix composite (MMC) layers using micron sized AlN particles via friction stir processing (FSP) in order to enhance surface mechanical properties. Micro structural evaluation using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) indicated that an increase in traverse speed and a decrease in rotational speed cause a reduction in the grain size of different groove width (0,0.4,0.8,1.2 mm) of stir zone (SZ) for the specimens friction stir processed (FSPed) without AlN particles. It was found that upon addition of AlN particles, wear properties were improved. This behavior was further supported by SEM images of wear surfaces. Results demonstrated that the micro composite produced by FSP exhibited enhanced wear resistance and higher average friction coefficient in comparison with pure copper. Tensile properties and fracture characteristics of the specimens FSPed with and without AlN particles and pure copper were also evaluated. According to the results, the MMC layer produced by FSP showed higher strength and lower elongation than pure copper while a remarkable elongation was observed for FSPed specimen without AlN particles and been greatly developed by the use of AlN.
This document summarizes a research study on producing an aluminum metal matrix composite with dual reinforcement of multi-walled carbon nanotubes and silicon carbide particles. Aluminum powder was mechanically milled with varying volumes of MWCNTs and SiC to improve dispersion of the nanotubes. The composite powders were then hot pressed into pellets and characterized. SEM images showed the SiC helped disperse the MWCNTs in the aluminum matrix. Hardness testing found the dual reinforced composites had significantly higher hardness than pure aluminum. The study demonstrated that powder metallurgy can be used to fabricate aluminum composites with improved properties through MWCNT and SiC reinforcement.
Investigation of Mechanical Properties of Pure Aluminum by Variation of Coppe...IRJET Journal
The document investigates the effect of copper content on the mechanical properties of aluminum alloys produced using die casting. Four aluminum alloys were made with copper content ranging from 1.62% to 17.31%. Tensile testing showed that ultimate tensile strength increased linearly with copper content, with the highest strength of 121.98 MPa achieved at 17.31% copper. The document also reviews literature on how copper additions influence the hardness, strength and other properties of aluminum and other alloys. In general, copper increases strength and hardness but can reduce ductility and corrosion resistance.
The document experimentally investigates the tensile strength of the aluminum alloy Al 6351 for potential use in aerospace structural applications. Standard tensile test specimens of 12mm and 16mm diameters were prepared and tested on a universal testing machine. The results found the tensile strength of Al 6351 to be between 231-247MPa and elongation between 18-20%, meeting the required strength for aerospace structures. The document concludes that Al 6351, currently used in pressure vessels, may also be suitable for aerospace applications given its strength properties and low production costs.
This document summarizes a study on the design and analysis of a butterfly valve disc using aluminum (1100) and an Al-CNT4% composite material. A butterfly valve was designed using Pro-E software and its deflection was analyzed using Ansys software for the two materials. The analysis found that the deflection of the Al-CNT4% composite disc was around 7 times less than the aluminum (1100) disc when subjected to various pressures. Therefore, the Al-CNT4% composite is more stable than aluminum (1100) for the application of a butterfly valve disc.
Carburization is a thermo-chemical treatment generally employed to enhance the
surface (wear) properties of low carbon steels. The recent carburization studies also
focus considerable positive impact on bulk properties like tensile strength and
toughness. In view of these observations, the present study focuses on mechanical
properties and microstructure of carburized steels. Accordingly, the commercially
available three types of case hardenable steels like plain carbon (EN 3), alloy steels
with only ferrite stabilizer (20MnCr5) and with both ferrite (Cr) and austenite (Ni)
stabilizers (EN 353) were initially normalized to standardize the room temperature
structure before carburizing and machined to ASTM standards to prepare the
specimens. The machined specimens were gas carburized using carburizing furnace
for 2.5 mm case depth and furnace cooled. Tensile and hardness tests were conducted
before and after carburization. The plain carbon steel displayed slight reduction in
tensile strength and the steels with alloying elements increased the tensile strength
considerably. It was also found that Ni and Cr restrict the grain growth and increase
the strength of steel even in furnace cooled condition. Microstructure analysis of
carburized steels revealed markable impact on the type and distribution of room
temperature phases. The carbon content in the case was nearly 0.8 wt. % after
carburization and hardness increase in the surface ranges from 130 to 170% as that
of its original hardness. The combined effect of Ni and Cr also improves
hardenability.
For the first time, amorphous aluminium-copper (Al-Cu) alloy nanowires decorated with carbon spheres
(CS) were synthesised from waste engine oil (WEO) as a starting material. The synthesis process was
carried out in two-stage thermal chemical vapour deposition system under typical synthesis condition of
5.33 wt% ferrocene as catalyst, precursor and synthesis temperature of 450 and 700 °C, respectively.
Metal contaminants of Al and Cu in WEO promote the growth of amorphous Al-Cu alloy nanowires and
high carbon content in WEO undeniable promotes the growth of CS. Field emission scanning electron
microscopy analysis showed that the amorphous Al-Cu alloy nanowires dimension was about 120 nm in
diameter and a few micrometres in length, while the diameter of CS were a few hundred nanometre to
micrometre-sized. X-ray diffraction pattern of amorphous Al-Cu alloy nanowires revealed the formation of
a,c
, I. M. Isa
a,c
,
different Al-Cu phases. This study offers a new and simple technique to synthesise amorphous Al-Cu
alloy nanowires decorated with CS from waste material namely WEO. The newly produced nanomaterials
open up potential application in energy storage devices.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
THE JOINING OF THREE DISSIMILAR METALLIC ALLOYS BY A SINGLE-PASS FRICTION STI...sorayaomidi
This document summarizes research on joining three dissimilar metallic alloys (5083 aluminum alloy, 6061 aluminum alloy, and steel) using single-pass friction stir welding. The maximum joint efficiency achieved was 73% using a rotational speed of 900 rpm, welding speed of 20 mm/min, and a diffusion technique without direct contact between the welding tool and the steel surface. Microstructural analysis found an intermetallic reaction layer formed at the welded interfaces that enhanced joint strength. Tensile tests on the welded specimens found failures typically occurred on the 6061 aluminum alloy side. Diffusion welding without direct tool contact was found to be preferable to minimize wear and generated forces during the welding process when joining these dissimilar materials
Effects of Cu on Microstructure and Mechanical Properties of Mg Added Al-Si-C...IRJET Journal
1) The document discusses the effects of adding copper and magnesium on the microstructure and mechanical properties of an Al-Si-Cu (A319) alloy.
2) Testing found that adding both copper and magnesium improved properties like hardness, tensile strength, and wear resistance compared to the base alloy, due to precipitates like Mg2Si and Al2Cu forming.
3) The alloy with 4% copper and magnesium added showed the highest strength, with an ultimate tensile strength over 40% higher than the base alloy after heat treatment, due to the combined strengthening effects.
The document discusses research on developing Aluminum 6061 metal matrix composites reinforced with multi-walled carbon nanotubes. It aims to study the microstructure, hardness, and wear properties of as-cast, heat treated, and extruded composites. The composites were fabricated using stir casting and tested to evaluate how the carbon nanotube content affects the mechanical properties. Results showed uniform distribution of carbon nanotubes in the aluminum matrix and increased hardness with higher carbon nanotube content. Wear properties of the different composite conditions were also analyzed and discussed.
Experimental evaluations and performance of the aluminum silicon carbide par...IAEME Publication
This document summarizes an experimental study on aluminum-silicon carbide particle metal matrix composites. Ring-shaped composites were fabricated using solid-state processing with varying sintering temperatures and times. The composites were subjected to thermal shock at +800C and -800C, and their radial crushing strength was tested. Micrographs of the fractured surfaces were analyzed. Thermal shock from sub-ambient temperatures was found to be more damaging than from elevated temperatures. Failure from elevated temperatures was dominated by cavity formation at interfaces, while sub-ambient temperatures caused more interfacial and matrix damage. The study evaluated the effect of reinforcement particles on the mechanical properties of the composites.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Yutong Liu - Final Report - Anodized Aluminium Oxide (AAO)Yutong Liu
This document summarizes research on forming iron oxide nanoparticles within the nano-pore structures of anodized aluminum oxide (AAO). It first discusses the process of creating the AAO film through a two-step anodization process and its hexagonal pore structure. It then reviews previous work demonstrating the intrinsic peroxidase activity of iron oxide nanoparticles. The research aims to investigate iron oxide nanoparticle formation kinetics within the AAO pores using electrochemical impedance spectroscopy (EIS) and equivalent circuit modeling. The document outlines the experimental design which involves fabricating AAO samples with varying iron hydroxide and iron oxide nanoparticle formation times, and then analyzing them using EIS to model the equivalent circuit and calculate parameter values.
Comparison of corrosion behaviour of commercial aluminium engine block and pi...msejjournal
The corrosion behavior of commercial aluminium alloy engine block and piston was investigated in 3.5% NaCl solution. The study was done by conventional gravimetric measurements and complemented by scanning electron microscopy (SEM) and X-ray analyzer (EDX) investigations. The results obtained indicate that the alloys suffers a process of corrosion localized to the area surrounding the precipitates of the Al (Si, Mg) and Al-Mg, which resulted in hemispherical pits. No evidence was found of the formation of crystallographic pitting for exposure times up to 54 days. Gravimetric analysis confirmed that with varying exposure periods the weight loss of the alloys increases and the normal corrosion rate profile of an initial steep rise followed by subsequent fall were observed for both alloys. The rate of corrosion of piston was found to be lower than that of engine block due to presence of Ni and lower percentages of Fe in aluminium piston alloy.
The document discusses the materials science of ball bonding used in microelectronics. Ball bonding and wedge bonding are solid state welds that provide electrical connections from chips to substrates. The physics and chemistry involved are not fully understood, though it is known that elevated temperatures enhance the process. There are several theories to explain the mechanism, including considerations of plastic deformation, defect generation, temperature rise, and diffusion. Experimental studies show significant temperature increases at the interface during bonding. Ultrasonics are found to enhance plastic deformation and defect generation. The formation of intermetallic phases is key to creating strong welds, and coverage by these phases can be seen particularly with gold bonding but less so with copper.
The document provides an overview of compression molding processes for thermosetting plastics. It discusses how compression molding uses a heated press to mold thermosetting compounds into shape. It also describes transfer molding as a similar process using either a pot or plunger to force the compound into a mold. The document outlines several types of transfer molding and their advantages.
Compression molding involves placing plastic material into a heated mold cavity, closing the mold, and applying pressure and heat to compress the material into shape. It is commonly used to make electrical components. Transfer molding similarly uses pressure to mold thermoset plastics, but involves transferring the material from a heated pot into the mold cavity. This document discusses these processes, providing details on their working principles, pros and cons, and an example of using compression molding to fabricate a microlens array from polycarbonate and glass for optical applications.
Analysis of Al 6061-TiO2 -CNT Metal Matrix Composites Produced by Stir Castin...Dr. Amarjeet Singh
Aluminium Hybrid Composites are the new groupof
metal matrix composites (MMCs) due to their attractive
properties like high ductility, high conductivity, light weight
and high strength to weight ratio and is a response to the
dynamic ever-increasing demand of these super material in
the field of aircrafts and marines. Carbon Nanotube (CNTs)
are also known for their high strength and stiffness and their
low density which when combined together makes CNTs an
ideal reinforcement. This work briefly reviews the research
revelation of an Aluminium (Al-6061) based hybrid metal
matrix composite reinforced with CNTs and TiO2. The
Hybrid Aluminium Metal Matrix Composites (AMMCs) is
prepared with various CNTs weight percentages (0, 0.5, 1 and
1.5 wt. %) and keeping TiO2 weight percentage fixed to
1%.Stir Casting (SC) is focused in general to successfully
fabricate the MMCs. The discussion of this work revolves
around tensile test, hardness test, and Scanning Electron
Microscope (SEM) of the MMC. The mechanical properties
of the fabricated MMCs materials like tensile strength,
hardness and impact strength is found by using these
experimental methods. It has been observed that the tensile
strength of the MMCs increases in the presence of TiO2 and
CNTs and increases even more with the increase in the weight
fraction of CNTs. Same results have been obtained for
hardness and impact strength where there is an increase in
them in the presence of TiO2 and CNT and their value
increases even further with increase in weight fraction of
CNTs.
This document summarizes research on the degradation of high-temperature materials used in traditional and modern energy systems. It discusses oxidation and microstructural degradation issues affecting materials in steam generators and fossil fuel plants. It presents experimental data on oxidation kinetics of steels from laboratory tests and power plants. The document also examines challenges for higher-temperature materials in advanced fossil plants. Further, it explores using nanocrystalline alloys and graphene coatings to improve oxidation resistance of materials for solid oxide fuel cells and other applications. The research involves collaboration with multiple universities and industry partners.
The main objective of this project is to be produce copper reinforced metal matrix composite (MMC) layers using micron sized AlN particles via friction stir processing (FSP) in order to enhance surface mechanical properties. Micro structural evaluation using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) indicated that an increase in traverse speed and a decrease in rotational speed cause a reduction in the grain size of different groove width (0,0.4,0.8,1.2 mm) of stir zone (SZ) for the specimens friction stir processed (FSPed) without AlN particles. It was found that upon addition of AlN particles, wear properties were improved. This behavior was further supported by SEM images of wear surfaces. Results demonstrated that the micro composite produced by FSP exhibited enhanced wear resistance and higher average friction coefficient in comparison with pure copper. Tensile properties and fracture characteristics of the specimens FSPed with and without AlN particles and pure copper were also evaluated. According to the results, the MMC layer produced by FSP showed higher strength and lower elongation than pure copper while a remarkable elongation was observed for FSPed specimen without AlN particles and been greatly developed by the use of AlN.
This document summarizes a research study on producing an aluminum metal matrix composite with dual reinforcement of multi-walled carbon nanotubes and silicon carbide particles. Aluminum powder was mechanically milled with varying volumes of MWCNTs and SiC to improve dispersion of the nanotubes. The composite powders were then hot pressed into pellets and characterized. SEM images showed the SiC helped disperse the MWCNTs in the aluminum matrix. Hardness testing found the dual reinforced composites had significantly higher hardness than pure aluminum. The study demonstrated that powder metallurgy can be used to fabricate aluminum composites with improved properties through MWCNT and SiC reinforcement.
Investigation of Mechanical Properties of Pure Aluminum by Variation of Coppe...IRJET Journal
The document investigates the effect of copper content on the mechanical properties of aluminum alloys produced using die casting. Four aluminum alloys were made with copper content ranging from 1.62% to 17.31%. Tensile testing showed that ultimate tensile strength increased linearly with copper content, with the highest strength of 121.98 MPa achieved at 17.31% copper. The document also reviews literature on how copper additions influence the hardness, strength and other properties of aluminum and other alloys. In general, copper increases strength and hardness but can reduce ductility and corrosion resistance.
The document experimentally investigates the tensile strength of the aluminum alloy Al 6351 for potential use in aerospace structural applications. Standard tensile test specimens of 12mm and 16mm diameters were prepared and tested on a universal testing machine. The results found the tensile strength of Al 6351 to be between 231-247MPa and elongation between 18-20%, meeting the required strength for aerospace structures. The document concludes that Al 6351, currently used in pressure vessels, may also be suitable for aerospace applications given its strength properties and low production costs.
This document summarizes a study on the design and analysis of a butterfly valve disc using aluminum (1100) and an Al-CNT4% composite material. A butterfly valve was designed using Pro-E software and its deflection was analyzed using Ansys software for the two materials. The analysis found that the deflection of the Al-CNT4% composite disc was around 7 times less than the aluminum (1100) disc when subjected to various pressures. Therefore, the Al-CNT4% composite is more stable than aluminum (1100) for the application of a butterfly valve disc.
Carburization is a thermo-chemical treatment generally employed to enhance the
surface (wear) properties of low carbon steels. The recent carburization studies also
focus considerable positive impact on bulk properties like tensile strength and
toughness. In view of these observations, the present study focuses on mechanical
properties and microstructure of carburized steels. Accordingly, the commercially
available three types of case hardenable steels like plain carbon (EN 3), alloy steels
with only ferrite stabilizer (20MnCr5) and with both ferrite (Cr) and austenite (Ni)
stabilizers (EN 353) were initially normalized to standardize the room temperature
structure before carburizing and machined to ASTM standards to prepare the
specimens. The machined specimens were gas carburized using carburizing furnace
for 2.5 mm case depth and furnace cooled. Tensile and hardness tests were conducted
before and after carburization. The plain carbon steel displayed slight reduction in
tensile strength and the steels with alloying elements increased the tensile strength
considerably. It was also found that Ni and Cr restrict the grain growth and increase
the strength of steel even in furnace cooled condition. Microstructure analysis of
carburized steels revealed markable impact on the type and distribution of room
temperature phases. The carbon content in the case was nearly 0.8 wt. % after
carburization and hardness increase in the surface ranges from 130 to 170% as that
of its original hardness. The combined effect of Ni and Cr also improves
hardenability.
For the first time, amorphous aluminium-copper (Al-Cu) alloy nanowires decorated with carbon spheres
(CS) were synthesised from waste engine oil (WEO) as a starting material. The synthesis process was
carried out in two-stage thermal chemical vapour deposition system under typical synthesis condition of
5.33 wt% ferrocene as catalyst, precursor and synthesis temperature of 450 and 700 °C, respectively.
Metal contaminants of Al and Cu in WEO promote the growth of amorphous Al-Cu alloy nanowires and
high carbon content in WEO undeniable promotes the growth of CS. Field emission scanning electron
microscopy analysis showed that the amorphous Al-Cu alloy nanowires dimension was about 120 nm in
diameter and a few micrometres in length, while the diameter of CS were a few hundred nanometre to
micrometre-sized. X-ray diffraction pattern of amorphous Al-Cu alloy nanowires revealed the formation of
a,c
, I. M. Isa
a,c
,
different Al-Cu phases. This study offers a new and simple technique to synthesise amorphous Al-Cu
alloy nanowires decorated with CS from waste material namely WEO. The newly produced nanomaterials
open up potential application in energy storage devices.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
THE JOINING OF THREE DISSIMILAR METALLIC ALLOYS BY A SINGLE-PASS FRICTION STI...sorayaomidi
This document summarizes research on joining three dissimilar metallic alloys (5083 aluminum alloy, 6061 aluminum alloy, and steel) using single-pass friction stir welding. The maximum joint efficiency achieved was 73% using a rotational speed of 900 rpm, welding speed of 20 mm/min, and a diffusion technique without direct contact between the welding tool and the steel surface. Microstructural analysis found an intermetallic reaction layer formed at the welded interfaces that enhanced joint strength. Tensile tests on the welded specimens found failures typically occurred on the 6061 aluminum alloy side. Diffusion welding without direct tool contact was found to be preferable to minimize wear and generated forces during the welding process when joining these dissimilar materials
Effects of Cu on Microstructure and Mechanical Properties of Mg Added Al-Si-C...IRJET Journal
1) The document discusses the effects of adding copper and magnesium on the microstructure and mechanical properties of an Al-Si-Cu (A319) alloy.
2) Testing found that adding both copper and magnesium improved properties like hardness, tensile strength, and wear resistance compared to the base alloy, due to precipitates like Mg2Si and Al2Cu forming.
3) The alloy with 4% copper and magnesium added showed the highest strength, with an ultimate tensile strength over 40% higher than the base alloy after heat treatment, due to the combined strengthening effects.
The document discusses research on developing Aluminum 6061 metal matrix composites reinforced with multi-walled carbon nanotubes. It aims to study the microstructure, hardness, and wear properties of as-cast, heat treated, and extruded composites. The composites were fabricated using stir casting and tested to evaluate how the carbon nanotube content affects the mechanical properties. Results showed uniform distribution of carbon nanotubes in the aluminum matrix and increased hardness with higher carbon nanotube content. Wear properties of the different composite conditions were also analyzed and discussed.
Experimental evaluations and performance of the aluminum silicon carbide par...IAEME Publication
This document summarizes an experimental study on aluminum-silicon carbide particle metal matrix composites. Ring-shaped composites were fabricated using solid-state processing with varying sintering temperatures and times. The composites were subjected to thermal shock at +800C and -800C, and their radial crushing strength was tested. Micrographs of the fractured surfaces were analyzed. Thermal shock from sub-ambient temperatures was found to be more damaging than from elevated temperatures. Failure from elevated temperatures was dominated by cavity formation at interfaces, while sub-ambient temperatures caused more interfacial and matrix damage. The study evaluated the effect of reinforcement particles on the mechanical properties of the composites.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Yutong Liu - Final Report - Anodized Aluminium Oxide (AAO)Yutong Liu
This document summarizes research on forming iron oxide nanoparticles within the nano-pore structures of anodized aluminum oxide (AAO). It first discusses the process of creating the AAO film through a two-step anodization process and its hexagonal pore structure. It then reviews previous work demonstrating the intrinsic peroxidase activity of iron oxide nanoparticles. The research aims to investigate iron oxide nanoparticle formation kinetics within the AAO pores using electrochemical impedance spectroscopy (EIS) and equivalent circuit modeling. The document outlines the experimental design which involves fabricating AAO samples with varying iron hydroxide and iron oxide nanoparticle formation times, and then analyzing them using EIS to model the equivalent circuit and calculate parameter values.
Comparison of corrosion behaviour of commercial aluminium engine block and pi...msejjournal
The corrosion behavior of commercial aluminium alloy engine block and piston was investigated in 3.5% NaCl solution. The study was done by conventional gravimetric measurements and complemented by scanning electron microscopy (SEM) and X-ray analyzer (EDX) investigations. The results obtained indicate that the alloys suffers a process of corrosion localized to the area surrounding the precipitates of the Al (Si, Mg) and Al-Mg, which resulted in hemispherical pits. No evidence was found of the formation of crystallographic pitting for exposure times up to 54 days. Gravimetric analysis confirmed that with varying exposure periods the weight loss of the alloys increases and the normal corrosion rate profile of an initial steep rise followed by subsequent fall were observed for both alloys. The rate of corrosion of piston was found to be lower than that of engine block due to presence of Ni and lower percentages of Fe in aluminium piston alloy.
The document discusses the materials science of ball bonding used in microelectronics. Ball bonding and wedge bonding are solid state welds that provide electrical connections from chips to substrates. The physics and chemistry involved are not fully understood, though it is known that elevated temperatures enhance the process. There are several theories to explain the mechanism, including considerations of plastic deformation, defect generation, temperature rise, and diffusion. Experimental studies show significant temperature increases at the interface during bonding. Ultrasonics are found to enhance plastic deformation and defect generation. The formation of intermetallic phases is key to creating strong welds, and coverage by these phases can be seen particularly with gold bonding but less so with copper.
The document provides an overview of compression molding processes for thermosetting plastics. It discusses how compression molding uses a heated press to mold thermosetting compounds into shape. It also describes transfer molding as a similar process using either a pot or plunger to force the compound into a mold. The document outlines several types of transfer molding and their advantages.
Compression molding involves placing plastic material into a heated mold cavity, closing the mold, and applying pressure and heat to compress the material into shape. It is commonly used to make electrical components. Transfer molding similarly uses pressure to mold thermoset plastics, but involves transferring the material from a heated pot into the mold cavity. This document discusses these processes, providing details on their working principles, pros and cons, and an example of using compression molding to fabricate a microlens array from polycarbonate and glass for optical applications.
(1) Compression molding is a manufacturing process used to mold thermosetting materials under heat and pressure in a mold cavity.
(2) The process involves preheating the molding material, placing it into the mold, applying pressure using a hydraulic press, and allowing the material to cure.
(3) Compression molding is commonly used to make electrical parts, dinnerware, gears, buttons, and automotive and medical components. It allows for high volume, low-cost production with minimal material waste.
This document discusses MEMS packaging at different levels. It describes microelectronic packaging as providing mechanical support, electrical connections and protection from environmental threats for integrated circuits. There are 5 levels of microelectronic packaging from the silicon chip to larger systems. MEMS and microsystem packaging aims to protect delicate core elements from mechanical or environmental damage during operation. Proper packaging design considers costs, environmental effects, reliability and achieving minimum electrical connections to prevent failures.
Today, plastic packaged integrated circuits are ubiquitous even for high-reliability applications. Reliability testing and standards play a key role in reliability engineering to achieve the necessary reliability performance. Traditional stress-based standards are easy to use but often over- or under-stress units and don’t focus on key vulnerabilities, particularly moisture-related ones. Knowledge-based standards have evolved to fix this, but rely on knowledge of mechanisms, control of board manufacturing conditions, and understanding and specifying end use conditions. This motivates a survey of plastic package mechanisms and testing with particular focus on moisture-related mechanisms and testing. The moisture-related examples will cover HAST testing, and the “popcorn” mechanism.
Learning Objectives
1.Understand the philosophy and methods behind reliability testing of ICs as applied to plastic-packaged ICs.
2.Learn the historical development of the JEDEC temperature-humidity-bias (HAST) moisture reliability testing standard.
3.Get a practical overview of key thermal, thermo-mechanical, moisture (chemical), and moisture (“popcorn”) mechanisms.
4.Appreciate how transformation of environmental conditions to conditions at the site of failure in the package is used to “scale” reliability models.
Compression molding is a process that molds material into a confined shape by applying pressure and usually heat. The process involves placing a charge in a mold cavity, closing the mold, applying pressure to squeeze the material and fill the cavity, and heating under pressure to cure the material. There are two main stages - plastication where the material is compressed and heated, and flow once the yield stress is exceeded allowing the mold to fill. Parameters like material quantity, pressure, temperature and cure time must be controlled. Common applications include dinnerware, buttons, and automotive parts.
1. The document discusses several power semiconductor devices used in power electronics, including power diodes, MOSFETs, IGBTs, and thyristors.
2. It provides information on the construction, operation, characteristics and switching behavior of each device.
3. The devices can be classified as either majority carrier devices like MOSFETs and diodes, which have very fast switching but higher voltage drops, or minority carrier devices like IGBTs and thyristors, which can block higher voltages but switch more slowly.
The document discusses power electronic systems and electrical drive systems. It provides an overview of power electronic converters, which are the heart of power electronics systems and are used to efficiently control and convert electric power. Modern electrical drive systems use power electronic converters with electric motors for variable speed applications, providing benefits like improved efficiency over classic fixed speed drives. The document describes different types of power electronic converters that can be used for DC drives and AC drives, including AC-DC, DC-DC, and voltage source converters.
This document provides an overview of power electronics and drives, focusing on modeling and simulation. It discusses power electronic systems and converters used in electrical drives, including DC and AC drives. It also covers modeling and control of electrical drives, specifically current controlled converters, modeling of power converters, and scalar control of induction motors. The document is intended to support a problem-based and project-oriented learning approach to the topics of power electronics, modeling, and drives.
The document discusses electrical drive systems and power electronic converters used in drives. It begins by explaining what power electronics are and their applications. Modern electrical drive systems often use power electronic converters to efficiently control electric motors and improve performance over traditional fixed speed drives. Power electronic converters can be configured in different ways depending on the drive application and whether an AC or DC motor is used. Common converter configurations for DC drives include AC-DC, AC-DC-DC, and various DC-DC converter topologies.
This document discusses surface preparation methods for stainless steel 316L, bronze CW451K, and titanium Ti6Al4V for bonding to polyurethane in marine cable connector assemblies. It examines the effects of grit-blasting these metals with different abrasive materials (aluminum oxide and silicon carbide grits) on surface roughness and cleanliness. Grit-blasting increased surface roughness but some grits left embedded particles that decreased bond strength to primer and polyurethane. Harder metals like titanium had less grit embedding than softer metals like bronze. The goal is to determine the optimal surface treatment to achieve strong polymer-to-metal bonding and reduce failures from cathodic delamination in marine environments.
Critical Investigation of Influence of Al/Cr Ratio on the Properties of High ...IRJET Journal
The document investigates the effect of Al/Cr ratio on the properties of high entropy alloys (HEAs) based on AlCoCrFeMnNi. It was found that:
1) Increasing the Al/Cr ratio refined the grain size and led to a phase transition from face centered cubic (FCC) to body centered cubic (BCC) structure.
2) Samples with low Al/Cr ratios showed a single FCC phase, while those with intermediate ratios showed mixed FCC+BCC phases and those with high ratios showed a single BCC phase.
3) The hardness of the HEAs increased with increasing Al/Cr ratio due to the higher aluminum content providing strengthening.
This document summarizes a study that investigated using different tooling materials to reduce distortions in flexible printed circuit boards during a co-curing manufacturing process with carbon fiber structures. Aluminum tooling initially caused curvature along the board's width and stretching along its length due to differences in the materials' thermal expansion coefficients. Switching to steel tooling, which has a lower coefficient, reduced the longitudinal stretching between solder ports as predicted. Aluminum pipe tooling solved the curvature issue but not the stretching. The study shows promise for manufacturing flexible printed circuit boards with carbon fiber composites while maintaining tight tolerances.
Buckling of slender composite concrete filled steel columnsRadhwan Faraj
This document summarizes research analyzing test data on 1817 composite concrete-filled steel columns. The test results are compared to calculations according to Eurocode 4 design methods. Several key findings are presented:
1) Test results for circular composite columns generally corresponded well with Eurocode 4 calculations. Test capacities of rectangular columns agreed with calculations when concrete strength was below 75 MPa.
2) Preloading composite members did not influence load-bearing capacity.
3) Analysis of stress distributions, preloading effects, and stress-strain curves was also examined.
4) Test/calculation ratios from the data indicate Eurocode 4 methods are generally conservative, with average ratios above 1.0 for different column types.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document summarizes a study on the partially melted zone (PMZ) in A356 Al-Si alloy welds produced using different welding techniques and with the alloy in different prior conditions. Key findings include:
1) Liquation was more severe in the PMZ of welds made with the alloy in the T6 condition compared to the as-cast condition, due to higher concentrations of silicon and magnesium at grain boundaries in the T6 condition.
2) Pulsed current gas tungsten arc welding resulted in less liquation in the PMZ compared to continuous current gas tungsten arc welding.
3) Microstructural examination and hardness testing showed coarser grains and more liquation products
The Effects of Copper Addition on the compression behavior of Al-Ca AlloyIOSR Journals
The Al-Ca-Cu alloys containing varying amount of Cu are used to study the effect of Cu addition on
their deformation behavior at varying strain rate (0.001/s, 0.01/s, 0.1/s, 1/s).The material is prepared using stir
casting technique The yield stress, flow stress and elastic limit are measured from the true stress-strain graph
.The Strain Rate sensitivity and strain hardening exponent are also determined for each material at different
strain rate. The Strain Rate Sensitivity of this alloy is very low. These values strongly demonstrate that
compressive deformation of Al-Ca-Cu alloys almost independent to the strain rate at room temperature
deformation.
EFFECT OF ANTIMONY ADDITION RELATIVE TO MICROSTRUCTURE AND MECHANICAL PROPERT...Rautomead Limited
It is well documented that the addition of antimony in pure lead increases tensile strength and reduced elongation. The goal of the present work is to identify the cause of these phenomena by investigation of the effects of the addition of Sb (1.25%) on the structure of pure continuously cast lead and lead alloy rods. The microstructure and morphology of both pure lead and lead 1.25% antimony were examined by digital optical microscope and scanning electron microscope respectively. Energy Dispersive X-ray Spectroscopy (EDX) was used to identify alloying elements. The results showed that the effect of additions of antimony on mechanical properties of lead-antimony alloys is mainly due to the solid solubility of the antimony element. Homogenized distribution of the antimony results in a decrease in the grain size of the pure lead. These smaller grains mean higher strength so long as there is a homogeneous grain structure
The document summarizes a study that investigated brazing 304L stainless steel corner joints using a nickel-based filler metal. Specifically:
- Brazing was performed under vacuum using a nickel-based shim and wire on 304L stainless steel sheets of different thicknesses.
- Microstructural examination found differences in the diffusion depth of nickel in the sheets based on their thicknesses. Microhardness was also affected by nickel diffusion.
- The nickel-based filler metal provided reasonable strength for the brazed joints between the 304L sheets of different thicknesses, as well as sufficient diffusion and filling for vacuum applications.
The document discusses cavitation erosion testing of stellite alloy weld overlays. It conducted tests using a vibratory method and cavitating liquid jet method to evaluate the erosion resistance of weld overlays made of ST6 and ST21 alloys. The results found that the grain size of the cobalt matrix in ST6 overlays affected their cavitation erosion resistance. ST6 overlays showed erosion rates about 1/13 to 1/7 times lower than SUS304 steel. Examination with SEM clarified the erosion mechanisms of SUS304 and ST6. Erosion rates from the cavitating liquid jet method correlated well with those from the vibratory method.
This document describes an electrochemical study of the anodic oxidation of titanium and a TA6V alloy in chromic acid electrolytes. Voltammetry and chronoamperometry experiments were conducted to investigate the formation of oxide films. In a chromic acid electrolyte without fluoride, a thin compact oxide film forms, while in a fluoride-containing electrolyte, a duplex film of a compact layer topped by a porous columnar layer grows. The voltammetry results show a breakdown of the compact film around 3 V/SCE and that alloying elements influence porous film formation. Chronoamperometry reveals the complex growth process involves residual current contributing to thickening of both layers, with overall electrochemical efficiency decreasing over
A Comparative Evaluation of Copper and Aluminium Wires and Cables in Building...Leonardo ENERGY
This document provides a comparative evaluation of copper and aluminium wires and cables used in building installations. It examines the physical properties of each material and compares their conductivity, current carrying capacity, weight, strength, installation characteristics, reliability of connections, susceptibility to corrosion, and relative costs. Copper is found to outperform aluminium in each category due to its higher conductivity, strength, resistance to creep and cold flow, smaller size for equivalent ampacity, and more reliable connections. While aluminium cables impose similar loads on buildings as copper, they require larger containment sizes due to their larger diameter and bending radii for an equivalent current capacity. The document concludes that copper remains the superior conductor material for wires and cables used in building power systems.
Ultrasonic welding of titanium alloy TiAl6V4 to aluminium alloy AA6111acezcq
This document summarizes research on ultrasonic spot welding of dissimilar aluminum alloy AA6111 and titanium alloy TiAl6V4 sheets. Key findings include:
1) No visible intermetallic reaction layer was detected at the weld interface, even with transmission electron microscopy.
2) Lap shear strength of the welds increased with welding time up to a plateau, with strengths reaching similar levels to aluminum-aluminum welds.
3) After natural aging of the aluminum alloy, the fracture mode transferred from ductile fracture in the aluminum to interfacial failure due to strength recovery of the aluminum.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Teyfik DEMİR, Mustafa ÜBEYLİ and R. Orhan YILDIRIM
TOBB ETU Mechanical Engineering, Söğütözü Cad. No:43, Ankara-TURKEY
Middle East Technical University, Mechanical Eng., Ankara-TURKEY
Effect of aging treatment on the ballistic behavor of aluminium alloy 7075 against 7.62 mm armor piercing projectiles
A Study of Anodic Voltage Drop in Aluminum Reduction Cell by Finite Element A...IJERA Editor
Aluminum extraction has a very high energy consumption process, so reducing energy consumption is one of
the most important roles in aluminum reduction cell design. The good path to achieve this goal can be made by
voltage savings at the anode assembly.
The aim of this work is todevelop3D thermo-electrical finite element model and validate based on actual
temperature measurements and electrical calculations for the anode assembly. The model is used to estimate the
temperature distribution and the anodic voltage drop over the anode assembly and to suggest alternative design
modifications to reduce the anodic voltage drop.
The effect of changing in stub diameter and chemical composition of cast iron on anodic voltage drop were
studied. The findings indicated that the effect of stub diameter is more effective as compare with the changing in
cast iron composition.
A Study of Anodic Voltage Drop in Aluminum Reduction Cell by Finite Element A...IJERA Editor
Aluminum extraction has a very high energy consumption process, so reducing energy consumption is one of
the most important roles in aluminum reduction cell design. The good path to achieve this goal can be made by
voltage savings at the anode assembly.
The aim of this work is todevelop3D thermo-electrical finite element model and validate based on actual
temperature measurements and electrical calculations for the anode assembly. The model is used to estimate the
temperature distribution and the anodic voltage drop over the anode assembly and to suggest alternative design
modifications to reduce the anodic voltage drop.
The effect of changing in stub diameter and chemical composition of cast iron on anodic voltage drop were
studied. The findings indicated that the effect of stub diameter is more effective as compare with the changing in
cast iron composition.
Effects of thermo mechanical simulation on the corrosion of steelJaideep Adusumelli
Performed numerous stress-strain elasticity tests along with impact test under controlled temperature and stress factors.
then the corrosion properties were studied based on the microstructures and corrosion current graphs.
IRJET- Study on Process Parameters of Diffusion Bonding of Titanium with ...IRJET Journal
This document studies the process parameters for diffusion bonding of titanium to stainless steel 304 and aluminum 6061. Diffusion bonding is a solid-state joining process that occurs through atomic transfer at the interface when materials are bonded under heat and pressure. The key parameters that influence bonding are temperature, time, and pressure. Experiments explored bonding titanium to stainless steel at 900°C for 90 minutes at 5MPa and bonding titanium to aluminum at 450°C for 90 minutes at 10MPa. Microhardness tests found these parameter combinations produced the highest bonding strengths at the interfaces. Optimization of diffusion bonding parameters is important for joining dissimilar metals like titanium.
The Recycling of Steel and Brass Chips to Produce Composite Materials via Col...theijes
In this study a novel method of direct conversion of brass (CuZn30) and steel (S355JR) chips into finished product without melting is introduced as an alternative to melting process. CuZn30 Brass and S355JR steel chips were used as constituents of composite materials. The chips were cold pressed at room temperature and were subjected to liquid phase sinterization. Hardness, compression and three point bending tests were used to investigate the mechanical properties of the obtained composite materials and compared with cast CuZn30 brass. The produced composite materials are shown to have comparable mechanical properties with bulk brass. It is also shown that the proposed method can be considered as an alternative to conventional production methods such as melting, extrusion ect. with relatively low costs.
Similar to Effects of Wire Type and Mold Compound on Wearout Reliability of Fineline BGA Package in Microelectronics Packaging (20)
Removing Uninteresting Bytes in Software FuzzingAftab Hussain
Imagine a world where software fuzzing, the process of mutating bytes in test seeds to uncover hidden and erroneous program behaviors, becomes faster and more effective. A lot depends on the initial seeds, which can significantly dictate the trajectory of a fuzzing campaign, particularly in terms of how long it takes to uncover interesting behaviour in your code. We introduce DIAR, a technique designed to speedup fuzzing campaigns by pinpointing and eliminating those uninteresting bytes in the seeds. Picture this: instead of wasting valuable resources on meaningless mutations in large, bloated seeds, DIAR removes the unnecessary bytes, streamlining the entire process.
In this work, we equipped AFL, a popular fuzzer, with DIAR and examined two critical Linux libraries -- Libxml's xmllint, a tool for parsing xml documents, and Binutil's readelf, an essential debugging and security analysis command-line tool used to display detailed information about ELF (Executable and Linkable Format). Our preliminary results show that AFL+DIAR does not only discover new paths more quickly but also achieves higher coverage overall. This work thus showcases how starting with lean and optimized seeds can lead to faster, more comprehensive fuzzing campaigns -- and DIAR helps you find such seeds.
- These are slides of the talk given at IEEE International Conference on Software Testing Verification and Validation Workshop, ICSTW 2022.
Communications Mining Series - Zero to Hero - Session 1DianaGray10
This session provides introduction to UiPath Communication Mining, importance and platform overview. You will acquire a good understand of the phases in Communication Mining as we go over the platform with you. Topics covered:
• Communication Mining Overview
• Why is it important?
• How can it help today’s business and the benefits
• Phases in Communication Mining
• Demo on Platform overview
• Q/A
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
- How to streamline operations with automated policy checks on container images
GraphSummit Singapore | The Art of the Possible with Graph - Q2 2024Neo4j
Neha Bajwa, Vice President of Product Marketing, Neo4j
Join us as we explore breakthrough innovations enabled by interconnected data and AI. Discover firsthand how organizations use relationships in data to uncover contextual insights and solve our most pressing challenges – from optimizing supply chains, detecting fraud, and improving customer experiences to accelerating drug discoveries.
Enchancing adoption of Open Source Libraries. A case study on Albumentations.AIVladimir Iglovikov, Ph.D.
Presented by Vladimir Iglovikov:
- https://www.linkedin.com/in/iglovikov/
- https://x.com/viglovikov
- https://www.instagram.com/ternaus/
This presentation delves into the journey of Albumentations.ai, a highly successful open-source library for data augmentation.
Created out of a necessity for superior performance in Kaggle competitions, Albumentations has grown to become a widely used tool among data scientists and machine learning practitioners.
This case study covers various aspects, including:
People: The contributors and community that have supported Albumentations.
Metrics: The success indicators such as downloads, daily active users, GitHub stars, and financial contributions.
Challenges: The hurdles in monetizing open-source projects and measuring user engagement.
Development Practices: Best practices for creating, maintaining, and scaling open-source libraries, including code hygiene, CI/CD, and fast iteration.
Community Building: Strategies for making adoption easy, iterating quickly, and fostering a vibrant, engaged community.
Marketing: Both online and offline marketing tactics, focusing on real, impactful interactions and collaborations.
Mental Health: Maintaining balance and not feeling pressured by user demands.
Key insights include the importance of automation, making the adoption process seamless, and leveraging offline interactions for marketing. The presentation also emphasizes the need for continuous small improvements and building a friendly, inclusive community that contributes to the project's growth.
Vladimir Iglovikov brings his extensive experience as a Kaggle Grandmaster, ex-Staff ML Engineer at Lyft, sharing valuable lessons and practical advice for anyone looking to enhance the adoption of their open-source projects.
Explore more about Albumentations and join the community at:
GitHub: https://github.com/albumentations-team/albumentations
Website: https://albumentations.ai/
LinkedIn: https://www.linkedin.com/company/100504475
Twitter: https://x.com/albumentations
Alt. GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using ...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Building RAG with self-deployed Milvus vector database and Snowpark Container...Zilliz
This talk will give hands-on advice on building RAG applications with an open-source Milvus database deployed as a docker container. We will also introduce the integration of Milvus with Snowpark Container Services.
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
Goodbye Windows 11: Make Way for Nitrux Linux 3.5.0!SOFTTECHHUB
As the digital landscape continually evolves, operating systems play a critical role in shaping user experiences and productivity. The launch of Nitrux Linux 3.5.0 marks a significant milestone, offering a robust alternative to traditional systems such as Windows 11. This article delves into the essence of Nitrux Linux 3.5.0, exploring its unique features, advantages, and how it stands as a compelling choice for both casual users and tech enthusiasts.
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
How to Get CNIC Information System with Paksim Ga.pptxdanishmna97
Pakdata Cf is a groundbreaking system designed to streamline and facilitate access to CNIC information. This innovative platform leverages advanced technology to provide users with efficient and secure access to their CNIC details.
Cosa hanno in comune un mattoncino Lego e la backdoor XZ?Speck&Tech
ABSTRACT: A prima vista, un mattoncino Lego e la backdoor XZ potrebbero avere in comune il fatto di essere entrambi blocchi di costruzione, o dipendenze di progetti creativi e software. La realtà è che un mattoncino Lego e il caso della backdoor XZ hanno molto di più di tutto ciò in comune.
Partecipate alla presentazione per immergervi in una storia di interoperabilità, standard e formati aperti, per poi discutere del ruolo importante che i contributori hanno in una comunità open source sostenibile.
BIO: Sostenitrice del software libero e dei formati standard e aperti. È stata un membro attivo dei progetti Fedora e openSUSE e ha co-fondato l'Associazione LibreItalia dove è stata coinvolta in diversi eventi, migrazioni e formazione relativi a LibreOffice. In precedenza ha lavorato a migrazioni e corsi di formazione su LibreOffice per diverse amministrazioni pubbliche e privati. Da gennaio 2020 lavora in SUSE come Software Release Engineer per Uyuni e SUSE Manager e quando non segue la sua passione per i computer e per Geeko coltiva la sua curiosità per l'astronomia (da cui deriva il suo nickname deneb_alpha).
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/building-and-scaling-ai-applications-with-the-nx-ai-manager-a-presentation-from-network-optix/
Robin van Emden, Senior Director of Data Science at Network Optix, presents the “Building and Scaling AI Applications with the Nx AI Manager,” tutorial at the May 2024 Embedded Vision Summit.
In this presentation, van Emden covers the basics of scaling edge AI solutions using the Nx tool kit. He emphasizes the process of developing AI models and deploying them globally. He also showcases the conversion of AI models and the creation of effective edge AI pipelines, with a focus on pre-processing, model conversion, selecting the appropriate inference engine for the target hardware and post-processing.
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Effects of Wire Type and Mold Compound on Wearout Reliability of Fineline BGA Package in Microelectronics Packaging
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Effects of Wire Type and Mold Compound on Wearout Reliability of
Semiconductor Flash Fineline BGA Package
C.L. Gan,1&2, Senior Member, IEEE, C. Francis1, B.L. Chan1, E.K. Ng1, U. Hashim2
1
Spansion (Penang) Sdn Bhd
Phase II Free Industrial Zone, 11900 Bayan Lepas, Penang, Malaysia
2
Institute of Nano Electronic Engineering (INEE)
Universiti Malaysia Perlis (UniMAP), 01000 Kangar Perlis, Malaysia
Email: clgan_pgg@yahoo.com
ABSTRACT
This paper discusses the influence of wire type (Cu and Au) and
the effect of mold compound on package reliability after exposure to
component reliability stress tests. Failure analysis is conducted to
identify associated failure mechanisms, and wearout reliability of
both wire types investigated after biased HAST (HAST) and
Temperature Cycling (TC). Weibull plots are plotted for each
reliability stress. Cu (Copper) ball bonds are found to have better
reliability margin in biased HAST stress compared to Au (Gold) ball
bonds for both mold compounds. Cu wire also exhibits a better
reliability margin compared to Au ball bonds in the TC stress test.
Failure mechanisms of HAST and TC are proposed for both wire
alloys in this paper.
Hence, extended reliability is crucial to determine the lifetime of
gold and copper ball bonds in microelectronics packaging. Cu-Al and
comparable Au-Al IMC growth kinetics have been studied and have
shown Cu-Al growth to be at least 5X slower than Au-Al IMC [16].
However, copper wirebonding still has some reliability challenges
and complex failure mechanisms to understand which are primary
barriers to the complete replacement of gold with copper in
wirebonded packages [17]. To help address this, in this study, we
have prepared 64 ball BGA (Ball Grid Array) packages assembled
with Gold and Pd-coated copper wire and submitted for biased
HAST (HAST) and Temperature Cycling (TC) tests. The test vehicle
construction is indicated in Figure 1.
Key words
Wearout reliability, weibull plot, HAST, TC, wire type
The primary considerations of finding an alternative to replace
gold wirebonding in microelectronic packaging are driven by new
technologies coming to market, in line with ever decreasing cost
expectations [1]. The currently common Au-Al intermetallic
compound (IMC) growth has been widely characterized and
analyzed [4-6]. Work is still ongoing with Au wire, as Zulkifli MN et
al. [7] suggested a new approach of examining the effect of the
individual phases and surroundings on the strengthening produced by
the Au–Al intermetallic compound; combining FEA based on
friction and wire bonding parameters and correlating TEM results
with results obtained from other techniques should enable a more
detailed understanding of the bondability and strength of
thermosonic gold wire bonds. Copper wirebonding, however,
appears to be the best candidate to meet cost and market
considerations, and various engineering studies on copper wire
deployment have been previously reported [2, 3]. Key technical
barriers such as Intermetal dielectric (IMD) cracking due to
excessive bonding, copper ball bond corrosion under moist
environments and extended reliability of copper ball bonds have been
identified accordingly [8-10]. In previous works, Copper ball bonds
have been shown to be more susceptible to moisture corrosion
compared to gold ball bonds, and undergo different corrosion
mechanisms in microelectronic packaging [11-12]. Our previous
studies indicate that Pd-coated copper ball bonds actually outperform
gold ball bonds in biased HAST wearout reliability [13]. Extended
reliability of High temperature storage life (HTSL) of copper ball
bonds in TSOP package is found with apparent activation energy
(E aa ) of ~ 0.70 eV compared to gold ball bonds [14]. Blish et al. [15]
investigated E aa of typical Au-Al IMC of 1.0 eV ~ 1.5eV which is
dependent on Al thickness as well as dopants. A similar range may
be appropriate for Cu as more reliability papers are published.
Figure 1: FBGA Package Interconnect Construction
EXPERIMENTAL RESULTS AND DISCUSSION
Materials used include 0.8 mil Pd-coated Cu wire (Cu) and 4N
(99.99% purity) gold (Au) wire, and 110 nm flash devices packaged
into fortified Fine-Pitch BGA packages with green (< 20 ppm
Chloride in content and pH values of 5.30 to 5.80) molding
compound and substrate. In this study, there are two variables,
namely mold compound type (A or B) and Wire type (Pd-coated Cu
wire and 4N Au wire) yielding four legs, all bonded on Fine pitch
64-ball BGA packages on a 2L substrate. The sample size used was
77 units for HAST and TC stresses, and the corresponding stress
tests conditions are tabulated in Table 1. After electrical test, good
samples were then subjected for Level 3 Preconditioning and 3 times
reflow at 260ºC as described in JEDEC IPC-STD 020 standard.
Each leg then went through HAST stress testing per JESD22-A110 at
130ºC/85%RH, 3.6V as well as TC per JESD22-A104 at -40ºC to
150 ºC. Electrical testing was conducted after several readpoints of
stress as well as to check Au and Cu ball bond integrity in terms of
its moisture and thermo-mechanical reliability.
Table 1: Summary of experimental matrix (for Au and Cu wires)
Compound
Stress Test
Test Conditions
SS
A
HAST
85%RH, 130 ºC, 3.60V
77
A
TC
-40ºC to 150 ºC
77
B
HAST
85%RH, 130 ºC, 3.60V
77
B
TC
-40ºC to 150 ºC
77
297
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INTRODUCTION
2. Back
All reliability data belong to the wearout portion of the reliability
curve (i.e. the bathtub curve) since the Weibull ß (shape parameter)
is greater than 1.0 for all legs. Mold compound B reveals a greater
time to failure in HAST and higher cycle to-failure (t first , t 50 and
t 63.2 ) in the TC test compared to mold compound A, even though
they have similar specifications (See Table 2). Possibly, the slightly
lower pH of EMC A might have played a role in the reduced
reliability as observed in other works [19]. Additionally, Cu ball
bonds show superior extended HAST reliability compared with Au
ball bonds for both mold compounds A and B (See Figure 2).
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FAILURE ANALYSIS AND MECHANISMS
Typical failure mechanisms of both biased HAST (HAST) of gold
(Au) and copper (Cu) ball bonds indicate IMC microcracking along
the AuAl and CuAl interfaces with the ball bonds. Figure 4 shows a
representative image of Cu ball bond microcracking and open after
3000 hours in HAST. We observed crack initiates from the edge of
Cu ball bonds and it appears to propagate towards the center of ball
bond, typically due to the ball bond force by the capillary, and
consistent with literature [9, 10, 13].
Weibull Plot (HAST Wearout Reliability)
0.00
Au_EMC A
Cu_EMC A
Au_EMC B
Cu_EMC B
Weibits
-1.00
y = 4.9585ln(x) - 39.652
R² = 0.8804
-2.00
y = 5.0585ln(x) - 41.954
R² = 0.9477
-3.00
y = 9.9595ln(x) - 80.853
R² = 0.996
-4.00
y = 8.676ln(x) - 72.19
R² = 0.9419
-5.00
500
5000
Hours
50000
Figure 2: Biased HAST Weibull reliability plots of Au and Cu ball
bonds with different EMC (Epoxy Molding Compounds)
Figure 4: Representative SEM image shows Cu ball bond
microcracking along CuAl interface after HAST 3000 hours
The wire type does not appear to be a key factor affecting the TC
reliability performance, although we did observe Cu ball bonds to
have slightly better TC extended reliability performance (higher t first ,
t 50 and t 63.2 ) compared to Au ball bonds (Figure 3). The coefficient
of thermal expansion (CTE) of mold compounds A and B are similar,
but perhaps the CTE difference between the two with respect to
silicon or the pH values (as mentioned earlier) might play a role.
EMC B (with α 2 of 3.0 x 10-5/°C) is closer to silicon die CTE of 3.0
ppm/°C compared with EMC A(α 2 of 0.7 x 10-5/°C) shows higher
TC reliability margin and longer cycles-to-failure for Au and Cu
wires. Increased internal stresses due to CTE mismatch might result
in faster dislocation movement and IMC formation. The key material
properties of EMC A and B are tabulated in Table 2.
Figure 5 shows the proposed Cu ball bond corrosion mechanism in
HAST test. The proposed corrosion mechanism as described in Eq. 1
to 3 below.
Weibull Plot (TC Wearout Reliability)
-1.00
Weibits
-2.00
Au_EMC A
Cu_EMC A
Au_EMC B
Cu_EMC B
y = 8.4311ln(x) - 81.641
R² = 0.9304
-3.00
-4.00
-5.00
2000
y = 11.956ln(x) - 115.45
R² = 0.9754
y = 7.2471ln(x) - 71.315
R² = 0.8618
(1)
(2)
(3)
Cu ball bond corrosion is most probably attributed to Cl- attacking
the edge of Cu ball bond region. Hydrolysis of IMC and AlCl 3 (an
intermediate product) in a moist environment forms Aluminum (III)
oxide which is a resistive layer and ionic Cl- is usually found at the
corroded ball bond [1, 10]. Equation 1 indicates the hydrolysis of
Cu 9 Al 4 into Al 2 O 3 and out gassing. Cracking of the Al 2 O 3 interface
of Cu to the Cu IMC might be due to out gassing of H 2 during
hydrolysis (as shown in Eq. 2 and 3) in between Cu IMC to Cu ball
bonds. Cracking usually starts at the Cu ball bond periphery and will
propagate towards center of Cu ball bond [9, 10, 13]. There is a
possibility that under moist conditions, internal oxidation of
intermetallic phases can result in oxidation of aluminium,
precipitation of the noble metal (Au or Cu), and generation of
hydrogen. Possible reactions resulting in formation of aluminium
oxide that might occur with gold and copper ball bonds are given in
Eq. 4 and Eq. 5 [11, 12].
2Au 4 Al + 3H 2 O Al 2 O 3 + 8Au + 6H
Cu 9 Al 4 + 6H 2 O 2(Al 2 O 3 ) + 9Cu + 12H
y = 8.347ln(x) - 82.541
R² = 0.9129
Cycles
Cu 9 Al 4 + 6H 2 O 2 (Al 2 O 3 ) + 6H 2 + 9Cu
CuAl 2 + 3H 2 O Al 2 O 3 + Cu + 3H 2
2AlCl 3 + 3H 2 O Al 2 O 3 + 6 HCl (acidic)
(4)
(5)
20000
Figure 3: Extended TC Weibull reliability plots of Au and Cu ball
bonds with different mold compounds.
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298
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Temperature cycling was conducted on the 4 legs of Au and Cu
ball bonds to examine its thermo-mechanical reliability performance
assembled with different epoxy mold compounds (EMC). It should
be noted that there is a mismatch in CTE (Coefficient of Thermal
expansion) between both Cu (17 ppm/°C) and Au ball bond (14
ppm/°C) compared to the silicon die (3.0 ppm/°C). This, combined
with the CTE mismatch between Au and Cu ball bonds with Al
bondpad of silicon die, will likely result in differential thermal
stresses during hot cycles (150°C) and cold cycles (-40°C). IMC
formation initiated at the edge of the ball bond (again, due to the ball
bond force of the capillary) and micro cracking was observed after
long cycles of thermal cycling effects. The micro cracking occurred
in between the ball bond and the IMC (as shown in Figure 8).
Figure 5: Proposed HAST failure mechanism of Cu ball bond
Au ball bonds also can exhibit Au oxidation and corrosion during
HAST stress. Figure 6 reveals the representative SEM image of Au
ball bonds and microcracking after HAST 2000 hours stress. Au is
commonly thought to have high corrosion resistance compared to Cu
ball bonds and has been deployed in microelectronics packaging for
more than 25 years. However we observe higher HAST reliability
margin of Cu ball bond compared to Au ball bond (Figure 2). The
AuAl HAST corrosion failure mechanism is illustrated in Figure 7.
Figure 8: Representative SEM image of Cu ball bond CuAl
interfacial microcracking after TC 9500 cycles
Figure 9 indicates the representative AuAl IMC microcracking after
9000 cycles of TC (Temperature Cycling) test in our wearout
reliability study.
Figure 6: Representative SEM image shows Au ball bond
(microcracking along AuAl interface after HAST 2000 hours)
3 Formation of AuAl
IMC micro- cracking
ball bond
Al Bondpad
Al Bondpad
1
Moisture
penetrate from
Edge of Au
ball bond
4 Lifted ball bond
Figure 9: Representative SEM image of Au ball bond AuAl
interfacial microcracking after TC 9000 cycles
ball bond
Al Bondpad
Figure 7: Proposed Failure mechanism of AuAl HAST oxidation
failure.
EFFECT OF MOLDING COMPOUND ON RELIABILITY
The epoxy mold compound (EMC) used in this evaluation are from
suppliers A and B. The key material characteristics of EMC A and B
are shown in Table 2. In general, the material specifications are very
similar between the two compounds. EMC B exhibits a longer timeto-first-failure in HAST extended reliability (Figure 2) and a higher
cycles-to-first-failure TC extended reliability tests (Figure 3)
compared to EMC A. EMC B also shows higher t 50 and t 63.2
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2
AuAl IMC will be
react with oxygen
From moisture>
oxidised AuAlO
layer
4. Back
compared to EMC A in HAST and TC stresses. These results are
summarized in Figure 10. It should be noted that both EMCs show
promising extended reliability results which far exceed the typical
requirements of 96 hours of HAST and 1000 cycles of TC according
to the JEDEC JESD47 standard.
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EMC types. This is an interesting finding since the mismatch in CTE
(Coefficient of Thermal expansion) between Cu (17 ppm/°C) is
greater than that of Au (14 ppm/°C). Normally speaking, reducing
CTE mismatch would tend to result in an improvement in reliability,
but there are clearly other factors at work here. Perhaps the fast IMC
growth of the AuAl interface plays a role in this case.
Table 3: Material properties of Au and Cu
Material Properties
Units
Au
Cu
Thermal Conductivity
W/mK
320
400
Electrical Resistivity
10-8 Ωm
2.2
1.72
Young’s Modulus
GPa
78
130
Vickers hardness
MPa
216
369
CONCLUSION AND SUMMARY
Figure 10: Plot of TC (cycles-to-failure) and HAST (hours-to-failure)
against EMC and wire types
Table 2: Key material characteristics of Epoxy Mold Compound
(EMC) A and B
Units
EMC A
EMC B
-5
10 /°C
1.1 +/- 0.3
0.7+/-0.3
10-5/°C
4.5 +/- 1.0
3.0+/-1.0
ACKNOWLEDGMENT
The authors would like to render appreciation to Gene Daszko and
Tony Reyes for their encouragement on the publication of this
technical paper.
REFERENCES
°C
125 +/- 15
125 +/- 15
ppm
< 10 ppm
< 10 ppm
Na content
ppm
< 10 ppm
< 10 ppm
pH
n/a
5.30
5.80
EFFECT OF WIRE TYPE ON RELIABILITY
Many previous studies reported Au wirebonds to have higher
reliability margins compared to Cu wirebonds. However, there is
very little published data on extended reliability of Au and Cu ball
bonds. Table 3 tabulates the major material properties comparing Au
and Cu metals. In our study, Cu ball bonds show significant higher
t 50 (mean-time-to failure) and t 63.2 (characteristic life) in HAST and
TC reliability compared to Au ball bond in FBGA package (as
indicated in Figure 10). Although Cu is commonly oxidized under
moist environments like the HAST test, an optimized package billof-material (such as that being used in our flash memory packages)
show excellent results and exceed Au performance with either EMC.
Similarly, Cu ball bonds exhibit a higher number of cycles-tofailure in TC test compared to Au ball bonds (Figure 3) regardless of
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300
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Material
characteristics
Linear coefficient of
thermal expansion 1
(CTE, α1)
Linear coefficient of
thermal expansion 2
(CTE, α 2 )
Glass transition
temperature (T g )
Cl- content
From the study, we analyzed the effects of wire alloy on
extended reliability of HAST and TC stresses. Cu ball bonds show
significant higher HAST reliability compared to Au ball bonds in the
FBGA package. In addition, Cu ball bonds are also superior to Au
ball bonds in an extended TC stress test. Overall, EMC B exhibits
higher TC and HAST reliability margins compared to EMC A with
either wire type.. However, both EMCs far exceed the minimum
requirement of 96 hours of HAST and 1000 cycles of TC according
to the JEDEC JESD47 standard.
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[8] C. L. Gan, T.T. Toong, C.P. Lim, C.Y. Ng, “Environmental
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