Eid Elsayed | Higher Technological Institute (original) (raw)

Papers by Eid Elsayed

Materials Science and Engineering: A, 2016

Abstract This study investigates the effect of adding 0.5 wt% ZnO nanoparticles into Sn–5 wt% Sb–... more Abstract This study investigates the effect of adding 0.5 wt% ZnO nanoparticles into Sn–5 wt% Sb–0.5 wt% Cu (SSC505) solder alloy on the growth of intermetallic compounds (IMCs) as well as the associated changes of microstructure. It was found that, the morphologies of the IMCs transformed to refinement forms due to the adsorption effect of ZnO nanoparticles. Systematic study of tensile properties was performed for bulk solders over a wide range of strain rates at various temperatures to determine the plastic deformation mechanism. Obviously, the ultimate tensile strength (UTS) and the yield stress ( σ y ) were improved. This can be attributed to reinforcement of ZnO nanoparticles, refined β-Sn grains and IMCs that could obstruct the dislocation slipping. The obtained results are consistent with the prediction of the classic theory of dispersion strengthening. Furthermore, the average activation energy ( Q ) for plain and composite solders were 57 and 59 kJ/mol, respectively, which close to that of pipe-diffusion mechanism in Sn based solder matrix.

Materials Science and Engineering: A, 2015

ABSTRACT Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) compo... more ABSTRACT Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) composite solder alloys have been studied. The variation in thermal behavior, microstructure and tensile characteristics associated with mixing of 0.5 wt% ZnO nano-metric particles to plain SSC505 solder were investigated. A slight increment in the melting temperature [ΔTm=0.89 °C] was recorded using differential scanning calorimetry (DSC) after addition of ZnO. X-Ray diffraction (XRD) analysis confirmed the existence of β-Sn, SbSn and Cu6Sn5 intermetallic compounds (IMCs) beside some of ZnO planes in SSC-ZnO composite solder. Field emission scanning electronic microscope (FE-SEM) investigation of SSC-ZnO composite solder revealed a homogenous uniform distribution, size refinement of IMCs and β-Sn grains. Addition of ZnO nano-metric particles into the plain SSC505 enhanced the yield stress σYS by ~12% and improved the ultimate tensile strength σUTS by ~13%. In addition, adding ZnO nano-metric particles was found to be effective for reducing ductility by ~43% of the plain solder due to the refinement of β-Sn grains within SSC-ZnO composite solder.

Superlattices and Microstructures, 2014

ABSTRACT The crystal structure and quality of ZnO thin films were enhanced by high temperature va... more ABSTRACT The crystal structure and quality of ZnO thin films were enhanced by high temperature vacuum annealing. High quality ZnO thin films have been grown on a-plane sapphire substrate by radio frequency (rf) magnetron sputtering method at a substrate temperature of 600 °C. A remarkable improvement in the epilayer quality were established by in situ high temperature annealing. The film quality, smoothness, the in plane stress, and the degree of epitaxy of the films have been evaluated. The crystalline quality was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy analyses. An extremely smooth ZnO films were achieved at higher annealing temperatures with root mean square roughness of 0.3 nm. The transverse optical mode A1(TO) observed in all the samples and the longitudinal optical mode A1(LO) appeared only at higher annealing temperatures over 800 °C in the micro-Raman scattering measurements. The strain of c-axis were relaxed and the lattice parameter was comparable to that of bulk ZnO at high annealing temperature of 900 °C.

Journal of Applied Sciences, 2012

Materials Science and Engineering: A, 2017

Abstract Eutectic Sn-Zn alloy is considered as one of the best lead free solder alloys in microel... more Abstract Eutectic Sn-Zn alloy is considered as one of the best lead free solder alloys in microelectronic industry. That motivates our group to select different weight percentage of Antimony (Sb) (0.5, 1.0, and 1.5 wt%) as an alloying to Sn-9.0Zn-0.5 Al solder alloy. The thermal behavior, microstructure modification as well as tensile properties of the new developed solder alloys were investigated. A slight increment of the melting temperature (∼ 1 °C) was recorded using differential scanning calorimetry (DSC) after additions of Sb. For 1.5 wt% of Sb, two endothermic peaks at 200.8 °C and 201.5 °C were observed, which are assigned as hypoeutectic Sn-Zn composition. X-ray diffraction (XRD) measurements confirm the existence of β-Sn phase, α-Zn phase, and Sb-Sn intermetallic compounds (IMCs). Scanning electron microscope (SEM) images indicate that the Sb additives refine the microstructure and form a uniform distribution of IMCs in the matrix of solder. The road-like α-Zn phase, Al 6 Zn 3 Sn and SbSn IMCs were clearly appeared in β-Sn matrix, which are responsible of the enhancement in tensile strength. Moreover, α-Zn phases in the Sn-9Zn-0.5Al-1.5Sb alloy were modified as needle-like, broken enormously, depleted, and circle shapes. Generally, The Sb-containing alloys have higher ultimate tensile strength (UTS) and lower elongation than Sb-free solder alloy due to the solid solution and second phase dispersion strengthening effect. The relationship between UTS and temperature follow the Arrhenius law. The average activation energies (Q) were found to be 44.4 ± 1.0 kJ/mol, and the average stress exponents (n) were usually around 5.3 ± 0.45, which are close to pipe diffusion controlled creep in β-Sn matrix.

Nanoscale Research Letters

Convective assembly technique which is a simple and scalable method was used for coating uniform ... more Convective assembly technique which is a simple and scalable method was used for coating uniform graphene oxide (GO) nanosheets on zinc oxide (ZnO) thin films. Upon UV irradiation, an enhancement in the on-off ratio was observed after functionalizing ZnO films by GO nanosheets. The calculations of on-off ratio, the device responsivity, and the external quantum efficiency were investigated and implied that the GO layer provides a stable pathway for electron transport. Structural investigations of the assembled GO and the heterostructure of GO on ZnO were performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The covered GO layer has a wide continuous area, with wrinkles and folds at the edges. In addition, the phonon lattice vibrations were investigated by Raman analysis. For GO and the heterostructure, a little change in the ratio between the D-band and G-band was found which means that no additional defects were formed within the heterostructure.

The creep phenomenon is considered as one of the most important deformation mechanisms under work... more The creep phenomenon is considered as one of the most important deformation mechanisms under working conditions. The present study has examined the microstructure and creep properties of Sn-9.0Zn-0.5Al solder alloy after adding a small amount of Antimony (Sb). Nominal compositions of Sb additions were chosen to be 0, 0.5, 1.0, and 1.5 wt.%. The minimum strain rate was reduced for the Sb containing solder alloy. The stress exponents, n, were found to be around 3.7 for all soldiers at 130˚C. The stress exponent increases as the temperature drops from 100˚C to 50˚C, except for the 1.0% Sb alloy, where n 5.3-6.1 at all the temperature range (T = 50˚C, 100˚C and 130˚C). The results reveal that the Sb-containing solder alloys have better creep resistance with greater ductility than the Sb-free alloy due to solid solution strengthening , and intermetallic compound SnSb particle hardening.

A B S T R A C T Eutectic Sn-Zn alloy is considered as one of the best lead free solder alloys in ... more A B S T R A C T Eutectic Sn-Zn alloy is considered as one of the best lead free solder alloys in microelectronic industry. That motivates our group to select different weight percentage of Antimony (Sb) (0.5, 1.0, and 1.5 wt%) as an alloying to Sn-9.0Zn-0.5 Al solder alloy. The thermal behavior, microstructure modification as well as tensile properties of the new developed solder alloys were investigated. A slight increment of the melting temperature (∼ 1 °C) was recorded using differential scanning calorimetry (DSC) after additions of Sb. For 1.5 wt% of Sb, two en-dothermic peaks at 200.8 °C and 201.5 °C were observed, which are assigned as hypoeutectic Sn-Zn composition. X-ray diffraction (XRD) measurements confirm the existence of β-Sn phase, α-Zn phase, and Sb-Sn intermetallic compounds (IMCs). Scanning electron microscope (SEM) images indicate that the Sb additives refine the mi-crostructure and form a uniform distribution of IMCs in the matrix of solder. The road-like α-Zn phase, Al 6 Zn 3 Sn and SbSn IMCs were clearly appeared in β-Sn matrix, which are responsible of the enhancement in tensile strength. Moreover, α-Zn phases in the Sn-9Zn-0.5Al-1.5Sb alloy were modified as needle-like, broken enormously , depleted, and circle shapes. Generally, The Sb-containing alloys have higher ultimate tensile strength (UTS) and lower elongation than Sb-free solder alloy due to the solid solution and second phase dispersion strengthening effect. The relationship between UTS and temperature follow the Arrhenius law. The average activation energies (Q) were found to be 44.4 ± 1.0 kJ/mol, and the average stress exponents (n) were usually around 5.3 ± 0.45, which are close to pipe diffusion controlled creep in β-Sn matrix.

Effect of adding 0.5 wt% ZnO nanoparticles, temperature and strain rate on tensile properties of ... more Effect of adding 0.5 wt% ZnO nanoparticles, temperature and strain rate on tensile properties of Sn–5.0 wt% Sb–0.5 wt% Cu (SSC505) lead free solder alloy a b s t r a c t This study investigates the effect of adding 0.5 wt% ZnO nanoparticles into Sn–5 wt% Sb–0.5 wt% Cu (SSC505) solder alloy on the growth of intermetallic compounds (IMCs) as well as the associated changes of microstructure. It was found that, the morphologies of the IMCs transformed to refinement forms due to the adsorption effect of ZnO nanoparticles. Systematic study of tensile properties was performed for bulk solders over a wide range of strain rates at various temperatures to determine the plastic deformation mechanism. Obviously, the ultimate tensile strength (UTS) and the yield stress (s y) were improved. This can be attributed to reinforcement of ZnO nanoparticles, refined β-Sn grains and IMCs that could obstruct the dislocation slipping. The obtained results are consistent with the prediction of the classic theory of dispersion strengthening. Furthermore, the average activation energy (Q) for plain and composite solders were 57 and 59 kJ/mol, respectively, which close to that of pipe-diffusion mechanism in Sn based solder matrix.

A series of Cu-doped Mn ferrites with the formula Mn 1-x Cu x Fe 2 O 4 (0.0 x 0.7) were synthesiz... more A series of Cu-doped Mn ferrites with the formula Mn 1-x Cu x Fe 2 O 4 (0.0 x 0.7) were synthesized by citrate auto combustion method. The structural characterization and morphology of the samples were examined by X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), and scanning electron microscopy (SEM). XRD and EDX confirmed the formation of single-phase cubic spinel structure. The electrical conductivity (s), dielectric constant (e 0), and dielectric loss factor (e 00) were studied as a function of temperature at different frequencies ranged from 100 kHz to 5 MHz. Increasing is observed in the values of s, e 0 , and e 00 with substitution of copper up to x D 0.3. Above this value, a decrease in s, e 0 , and e 00 was detected.

PbS thin films were deposited on glass substrates by a chemical bath deposition method. The effec... more PbS thin films were deposited on glass substrates by a chemical bath deposition method. The effect of varying the film thickness on the structural and optical properties has been investigated. XRD analysis reveals the crystallinity of the deposited PbS films with (200) preferred crystal orientation. Increasing the film thickness enhances the crystallinity of the films as well as decreases the strain and dislocation density. The surface morphology features were dramatically changed from small spherical grains to bead-like shape. The absence of impurities in the deposited films was confirmed by energy dispersive x-ray spectrometry (EDX) measurements. The optical constants of the deposited films were calculated and a small decrease in the band gap energy was observed with increasing the film thickness.

Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) composite sold... more Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) composite solder alloys have been studied. The variation in thermal behavior, microstructure and tensile characteristics associated with mixing of 0.5 wt% ZnO nano-metric particles to plain SSC505 solder were investigated. A slight increment in the melting temperature [ΔT m ¼0.89 1C] was recorded using differential scanning calorimetry (DSC) after addition of ZnO. X-Ray diffraction (XRD) analysis confirmed the existence of β-Sn, SbSn and Cu 6 Sn 5 intermetallic compounds (IMCs) beside some of ZnO planes in SSC-ZnO composite solder. Field emission scanning electronic microscope (FE-SEM) investigation of SSC-ZnO composite solder revealed a homogenous uniform distribution, size refinement of IMCs and β-Sn grains. Addition of ZnO nano-metric particles into the plain SSC505 enhanced the yield stress σ YS by $ 12% and improved the ultimate tensile strength σ UTS by $ 13%. In addition, adding ZnO nano-metric particles was found to be effective for reducing ductility by $ 43% of the plain solder due to the refinement of β-Sn grains within SSC-ZnO composite solder.

Sn-5 wt%Sb-0.5 wt%Cu (plain SSC505) and Sn-5 wt%Sb-0.5 wt%Cu-0.5 wt% ZnO (SSC-ZnO) composite sold... more Sn-5 wt%Sb-0.5 wt%Cu (plain SSC505) and Sn-5 wt%Sb-0.5 wt%Cu-0.5 wt% ZnO (SSC-ZnO) composite solder alloys have been studied. The variation in thermal behavior, microstructure and tensile characteristics associated with mixing of 0.5 wt% ZnO nano-metric particles to plain SSC505 solder were investigated. A slight increment in the melting temperature [ΔT m ¼0.89 1C] was recorded using differential scanning calorimetry (DSC) after addition of ZnO. X-Ray diffraction (XRD) analysis confirmed the existence of β-Sn, SbSn and Cu 6 Sn 5 intermetallic compounds (IMCs) beside some of ZnO planes in SSC-ZnO composite solder. Field emission scanning electronic microscope (FE-SEM) investigation of SSC-ZnO composite solder revealed a homogenous uniform distribution, size refinement of IMCs and β-Sn grains. Addition of ZnO nano-metric particles into the plain SSC505 enhanced the yield stress σ YS by $ 12% and improved the ultimate tensile strength σ UTS by $ 13%. In addition, adding ZnO nano-metric particles was found to be effective for reducing ductility by $ 43% of the plain solder due to the refinement of β-Sn grains within SSC-ZnO composite solder.

Convective assembly technique which is a simple and scalable method was used for coating uniform ... more Convective assembly technique which is a simple and scalable method was used for coating uniform graphene oxide (GO) nanosheets on zinc oxide (ZnO) thin films. Upon UV irradiation, an enhancement in the on-off ratio was observed after functionalizing ZnO films by GO nanosheets. The calculations of on-off ratio, the device responsivity, and the external quantum efficiency were investigated and implied that the GO layer provides a stable pathway for electron transport. Structural investigations of the assembled GO and the heterostructure of GO on ZnO were performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The covered GO layer has a wide continuous area, with wrinkles and folds at the edges. In addition, the phonon lattice vibrations were investigated by Raman analysis. For GO and the heterostructure, a little change in the ratio between the D-band and G-band was found which means that no additional defects were formed within the heterostructure.

Convective assembly technique which is a simple and scalable method was used for coating uniform ... more Convective assembly technique which is a simple and scalable method was used for coating uniform graphene oxide (GO) nanosheets on zinc oxide (ZnO) thin films. Upon UV irradiation, an enhancement in the on-off ratio was observed after functionalizing ZnO films by GO nanosheets. The calculations of on-off ratio, the device responsivity, and the external quantum efficiency were investigated and implied that the GO layer provides a stable pathway for electron transport. Structural investigations of the assembled GO and the heterostructure of GO on ZnO were performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The covered GO layer has a wide continuous area, with wrinkles and folds at the edges. In addition, the phonon lattice vibrations were investigated by Raman analysis. For GO and the heterostructure, a little change in the ratio between the D-band and G-band was found which means that no additional defects were formed within the heterostructure.

The crystal structure and quality of ZnO thin films were enhanced by high temperature vacuum anne... more The crystal structure and quality of ZnO thin films were enhanced by high temperature vacuum annealing. High quality ZnO thin films have been grown ona-plane sapphire substrate by radio frequency (rf) magnetron sputtering method at a substrate temperature of 600C. A remarkable improvement in the epilayer quality were established by in situ high temperature annealing. The film quality, smoothness, the in plane stress, and the degree
of epitaxy of the films have been evaluated. The crystalline quality was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy analyses. An extremely smooth ZnO films were achieved at higher annealing temperatures with root mean square roughness of 0.3 nm. The transverse optical mode A1(TO) observed in all the samples and the longitudinal optical mode A1(LO) appeared only at higher annealing temperatures over 800Cin the micro-Raman scattering measurements. The strain of c-axis were relaxed and the lattice parameter was comparable to that of bulk ZnO at high annealing temperature of 900C

Recently, nano-composite solders have been developed in the electronic packaging materials indust... more Recently, nano-composite solders have been developed in the electronic packaging materials industry to improve the creep and thermo-mechanical fatigue resistance of solder joints to be used in service at high temperatures and under thermo-mechanical fatigue conditions. This paper reviews the driving force for the development of nano-composite solders in the electronic packaging industry and the research advances of the composite solders developed. The rationale for the preparation of nano-composite solders are presented at first. Examples of two nano-composite solder fabrication methods, a mechanical mixing method and an in-situ method, are explained in detail. The achievements and enhancements in the nano-composite prepared solders are summarized. The difficulties and problems existing in the fabrication of nano-composite solders are discussed. Finally, a novel nano-structure composite solder, which attempts to solve the problems encountered in the fabrication of nano-composite solders, is introduced in detail. Guidelines for the development of nano-composite solders are then provided.

Materials Science and Engineering: A, 2016

Abstract This study investigates the effect of adding 0.5 wt% ZnO nanoparticles into Sn–5 wt% Sb–... more Abstract This study investigates the effect of adding 0.5 wt% ZnO nanoparticles into Sn–5 wt% Sb–0.5 wt% Cu (SSC505) solder alloy on the growth of intermetallic compounds (IMCs) as well as the associated changes of microstructure. It was found that, the morphologies of the IMCs transformed to refinement forms due to the adsorption effect of ZnO nanoparticles. Systematic study of tensile properties was performed for bulk solders over a wide range of strain rates at various temperatures to determine the plastic deformation mechanism. Obviously, the ultimate tensile strength (UTS) and the yield stress ( σ y ) were improved. This can be attributed to reinforcement of ZnO nanoparticles, refined β-Sn grains and IMCs that could obstruct the dislocation slipping. The obtained results are consistent with the prediction of the classic theory of dispersion strengthening. Furthermore, the average activation energy ( Q ) for plain and composite solders were 57 and 59 kJ/mol, respectively, which close to that of pipe-diffusion mechanism in Sn based solder matrix.

Materials Science and Engineering: A, 2015

ABSTRACT Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) compo... more ABSTRACT Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) composite solder alloys have been studied. The variation in thermal behavior, microstructure and tensile characteristics associated with mixing of 0.5 wt% ZnO nano-metric particles to plain SSC505 solder were investigated. A slight increment in the melting temperature [ΔTm=0.89 °C] was recorded using differential scanning calorimetry (DSC) after addition of ZnO. X-Ray diffraction (XRD) analysis confirmed the existence of β-Sn, SbSn and Cu6Sn5 intermetallic compounds (IMCs) beside some of ZnO planes in SSC-ZnO composite solder. Field emission scanning electronic microscope (FE-SEM) investigation of SSC-ZnO composite solder revealed a homogenous uniform distribution, size refinement of IMCs and β-Sn grains. Addition of ZnO nano-metric particles into the plain SSC505 enhanced the yield stress σYS by ~12% and improved the ultimate tensile strength σUTS by ~13%. In addition, adding ZnO nano-metric particles was found to be effective for reducing ductility by ~43% of the plain solder due to the refinement of β-Sn grains within SSC-ZnO composite solder.

Superlattices and Microstructures, 2014

ABSTRACT The crystal structure and quality of ZnO thin films were enhanced by high temperature va... more ABSTRACT The crystal structure and quality of ZnO thin films were enhanced by high temperature vacuum annealing. High quality ZnO thin films have been grown on a-plane sapphire substrate by radio frequency (rf) magnetron sputtering method at a substrate temperature of 600 °C. A remarkable improvement in the epilayer quality were established by in situ high temperature annealing. The film quality, smoothness, the in plane stress, and the degree of epitaxy of the films have been evaluated. The crystalline quality was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy analyses. An extremely smooth ZnO films were achieved at higher annealing temperatures with root mean square roughness of 0.3 nm. The transverse optical mode A1(TO) observed in all the samples and the longitudinal optical mode A1(LO) appeared only at higher annealing temperatures over 800 °C in the micro-Raman scattering measurements. The strain of c-axis were relaxed and the lattice parameter was comparable to that of bulk ZnO at high annealing temperature of 900 °C.

Journal of Applied Sciences, 2012

Materials Science and Engineering: A, 2017

Abstract Eutectic Sn-Zn alloy is considered as one of the best lead free solder alloys in microel... more Abstract Eutectic Sn-Zn alloy is considered as one of the best lead free solder alloys in microelectronic industry. That motivates our group to select different weight percentage of Antimony (Sb) (0.5, 1.0, and 1.5 wt%) as an alloying to Sn-9.0Zn-0.5 Al solder alloy. The thermal behavior, microstructure modification as well as tensile properties of the new developed solder alloys were investigated. A slight increment of the melting temperature (∼ 1 °C) was recorded using differential scanning calorimetry (DSC) after additions of Sb. For 1.5 wt% of Sb, two endothermic peaks at 200.8 °C and 201.5 °C were observed, which are assigned as hypoeutectic Sn-Zn composition. X-ray diffraction (XRD) measurements confirm the existence of β-Sn phase, α-Zn phase, and Sb-Sn intermetallic compounds (IMCs). Scanning electron microscope (SEM) images indicate that the Sb additives refine the microstructure and form a uniform distribution of IMCs in the matrix of solder. The road-like α-Zn phase, Al 6 Zn 3 Sn and SbSn IMCs were clearly appeared in β-Sn matrix, which are responsible of the enhancement in tensile strength. Moreover, α-Zn phases in the Sn-9Zn-0.5Al-1.5Sb alloy were modified as needle-like, broken enormously, depleted, and circle shapes. Generally, The Sb-containing alloys have higher ultimate tensile strength (UTS) and lower elongation than Sb-free solder alloy due to the solid solution and second phase dispersion strengthening effect. The relationship between UTS and temperature follow the Arrhenius law. The average activation energies (Q) were found to be 44.4 ± 1.0 kJ/mol, and the average stress exponents (n) were usually around 5.3 ± 0.45, which are close to pipe diffusion controlled creep in β-Sn matrix.

Nanoscale Research Letters

Convective assembly technique which is a simple and scalable method was used for coating uniform ... more Convective assembly technique which is a simple and scalable method was used for coating uniform graphene oxide (GO) nanosheets on zinc oxide (ZnO) thin films. Upon UV irradiation, an enhancement in the on-off ratio was observed after functionalizing ZnO films by GO nanosheets. The calculations of on-off ratio, the device responsivity, and the external quantum efficiency were investigated and implied that the GO layer provides a stable pathway for electron transport. Structural investigations of the assembled GO and the heterostructure of GO on ZnO were performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The covered GO layer has a wide continuous area, with wrinkles and folds at the edges. In addition, the phonon lattice vibrations were investigated by Raman analysis. For GO and the heterostructure, a little change in the ratio between the D-band and G-band was found which means that no additional defects were formed within the heterostructure.

The creep phenomenon is considered as one of the most important deformation mechanisms under work... more The creep phenomenon is considered as one of the most important deformation mechanisms under working conditions. The present study has examined the microstructure and creep properties of Sn-9.0Zn-0.5Al solder alloy after adding a small amount of Antimony (Sb). Nominal compositions of Sb additions were chosen to be 0, 0.5, 1.0, and 1.5 wt.%. The minimum strain rate was reduced for the Sb containing solder alloy. The stress exponents, n, were found to be around 3.7 for all soldiers at 130˚C. The stress exponent increases as the temperature drops from 100˚C to 50˚C, except for the 1.0% Sb alloy, where n 5.3-6.1 at all the temperature range (T = 50˚C, 100˚C and 130˚C). The results reveal that the Sb-containing solder alloys have better creep resistance with greater ductility than the Sb-free alloy due to solid solution strengthening , and intermetallic compound SnSb particle hardening.

A B S T R A C T Eutectic Sn-Zn alloy is considered as one of the best lead free solder alloys in ... more A B S T R A C T Eutectic Sn-Zn alloy is considered as one of the best lead free solder alloys in microelectronic industry. That motivates our group to select different weight percentage of Antimony (Sb) (0.5, 1.0, and 1.5 wt%) as an alloying to Sn-9.0Zn-0.5 Al solder alloy. The thermal behavior, microstructure modification as well as tensile properties of the new developed solder alloys were investigated. A slight increment of the melting temperature (∼ 1 °C) was recorded using differential scanning calorimetry (DSC) after additions of Sb. For 1.5 wt% of Sb, two en-dothermic peaks at 200.8 °C and 201.5 °C were observed, which are assigned as hypoeutectic Sn-Zn composition. X-ray diffraction (XRD) measurements confirm the existence of β-Sn phase, α-Zn phase, and Sb-Sn intermetallic compounds (IMCs). Scanning electron microscope (SEM) images indicate that the Sb additives refine the mi-crostructure and form a uniform distribution of IMCs in the matrix of solder. The road-like α-Zn phase, Al 6 Zn 3 Sn and SbSn IMCs were clearly appeared in β-Sn matrix, which are responsible of the enhancement in tensile strength. Moreover, α-Zn phases in the Sn-9Zn-0.5Al-1.5Sb alloy were modified as needle-like, broken enormously , depleted, and circle shapes. Generally, The Sb-containing alloys have higher ultimate tensile strength (UTS) and lower elongation than Sb-free solder alloy due to the solid solution and second phase dispersion strengthening effect. The relationship between UTS and temperature follow the Arrhenius law. The average activation energies (Q) were found to be 44.4 ± 1.0 kJ/mol, and the average stress exponents (n) were usually around 5.3 ± 0.45, which are close to pipe diffusion controlled creep in β-Sn matrix.

Effect of adding 0.5 wt% ZnO nanoparticles, temperature and strain rate on tensile properties of ... more Effect of adding 0.5 wt% ZnO nanoparticles, temperature and strain rate on tensile properties of Sn–5.0 wt% Sb–0.5 wt% Cu (SSC505) lead free solder alloy a b s t r a c t This study investigates the effect of adding 0.5 wt% ZnO nanoparticles into Sn–5 wt% Sb–0.5 wt% Cu (SSC505) solder alloy on the growth of intermetallic compounds (IMCs) as well as the associated changes of microstructure. It was found that, the morphologies of the IMCs transformed to refinement forms due to the adsorption effect of ZnO nanoparticles. Systematic study of tensile properties was performed for bulk solders over a wide range of strain rates at various temperatures to determine the plastic deformation mechanism. Obviously, the ultimate tensile strength (UTS) and the yield stress (s y) were improved. This can be attributed to reinforcement of ZnO nanoparticles, refined β-Sn grains and IMCs that could obstruct the dislocation slipping. The obtained results are consistent with the prediction of the classic theory of dispersion strengthening. Furthermore, the average activation energy (Q) for plain and composite solders were 57 and 59 kJ/mol, respectively, which close to that of pipe-diffusion mechanism in Sn based solder matrix.

A series of Cu-doped Mn ferrites with the formula Mn 1-x Cu x Fe 2 O 4 (0.0 x 0.7) were synthesiz... more A series of Cu-doped Mn ferrites with the formula Mn 1-x Cu x Fe 2 O 4 (0.0 x 0.7) were synthesized by citrate auto combustion method. The structural characterization and morphology of the samples were examined by X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), and scanning electron microscopy (SEM). XRD and EDX confirmed the formation of single-phase cubic spinel structure. The electrical conductivity (s), dielectric constant (e 0), and dielectric loss factor (e 00) were studied as a function of temperature at different frequencies ranged from 100 kHz to 5 MHz. Increasing is observed in the values of s, e 0 , and e 00 with substitution of copper up to x D 0.3. Above this value, a decrease in s, e 0 , and e 00 was detected.

PbS thin films were deposited on glass substrates by a chemical bath deposition method. The effec... more PbS thin films were deposited on glass substrates by a chemical bath deposition method. The effect of varying the film thickness on the structural and optical properties has been investigated. XRD analysis reveals the crystallinity of the deposited PbS films with (200) preferred crystal orientation. Increasing the film thickness enhances the crystallinity of the films as well as decreases the strain and dislocation density. The surface morphology features were dramatically changed from small spherical grains to bead-like shape. The absence of impurities in the deposited films was confirmed by energy dispersive x-ray spectrometry (EDX) measurements. The optical constants of the deposited films were calculated and a small decrease in the band gap energy was observed with increasing the film thickness.

Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) composite sold... more Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) composite solder alloys have been studied. The variation in thermal behavior, microstructure and tensile characteristics associated with mixing of 0.5 wt% ZnO nano-metric particles to plain SSC505 solder were investigated. A slight increment in the melting temperature [ΔT m ¼0.89 1C] was recorded using differential scanning calorimetry (DSC) after addition of ZnO. X-Ray diffraction (XRD) analysis confirmed the existence of β-Sn, SbSn and Cu 6 Sn 5 intermetallic compounds (IMCs) beside some of ZnO planes in SSC-ZnO composite solder. Field emission scanning electronic microscope (FE-SEM) investigation of SSC-ZnO composite solder revealed a homogenous uniform distribution, size refinement of IMCs and β-Sn grains. Addition of ZnO nano-metric particles into the plain SSC505 enhanced the yield stress σ YS by $ 12% and improved the ultimate tensile strength σ UTS by $ 13%. In addition, adding ZnO nano-metric particles was found to be effective for reducing ductility by $ 43% of the plain solder due to the refinement of β-Sn grains within SSC-ZnO composite solder.

Sn-5 wt%Sb-0.5 wt%Cu (plain SSC505) and Sn-5 wt%Sb-0.5 wt%Cu-0.5 wt% ZnO (SSC-ZnO) composite sold... more Sn-5 wt%Sb-0.5 wt%Cu (plain SSC505) and Sn-5 wt%Sb-0.5 wt%Cu-0.5 wt% ZnO (SSC-ZnO) composite solder alloys have been studied. The variation in thermal behavior, microstructure and tensile characteristics associated with mixing of 0.5 wt% ZnO nano-metric particles to plain SSC505 solder were investigated. A slight increment in the melting temperature [ΔT m ¼0.89 1C] was recorded using differential scanning calorimetry (DSC) after addition of ZnO. X-Ray diffraction (XRD) analysis confirmed the existence of β-Sn, SbSn and Cu 6 Sn 5 intermetallic compounds (IMCs) beside some of ZnO planes in SSC-ZnO composite solder. Field emission scanning electronic microscope (FE-SEM) investigation of SSC-ZnO composite solder revealed a homogenous uniform distribution, size refinement of IMCs and β-Sn grains. Addition of ZnO nano-metric particles into the plain SSC505 enhanced the yield stress σ YS by $ 12% and improved the ultimate tensile strength σ UTS by $ 13%. In addition, adding ZnO nano-metric particles was found to be effective for reducing ductility by $ 43% of the plain solder due to the refinement of β-Sn grains within SSC-ZnO composite solder.

Convective assembly technique which is a simple and scalable method was used for coating uniform ... more Convective assembly technique which is a simple and scalable method was used for coating uniform graphene oxide (GO) nanosheets on zinc oxide (ZnO) thin films. Upon UV irradiation, an enhancement in the on-off ratio was observed after functionalizing ZnO films by GO nanosheets. The calculations of on-off ratio, the device responsivity, and the external quantum efficiency were investigated and implied that the GO layer provides a stable pathway for electron transport. Structural investigations of the assembled GO and the heterostructure of GO on ZnO were performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The covered GO layer has a wide continuous area, with wrinkles and folds at the edges. In addition, the phonon lattice vibrations were investigated by Raman analysis. For GO and the heterostructure, a little change in the ratio between the D-band and G-band was found which means that no additional defects were formed within the heterostructure.

Convective assembly technique which is a simple and scalable method was used for coating uniform ... more Convective assembly technique which is a simple and scalable method was used for coating uniform graphene oxide (GO) nanosheets on zinc oxide (ZnO) thin films. Upon UV irradiation, an enhancement in the on-off ratio was observed after functionalizing ZnO films by GO nanosheets. The calculations of on-off ratio, the device responsivity, and the external quantum efficiency were investigated and implied that the GO layer provides a stable pathway for electron transport. Structural investigations of the assembled GO and the heterostructure of GO on ZnO were performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The covered GO layer has a wide continuous area, with wrinkles and folds at the edges. In addition, the phonon lattice vibrations were investigated by Raman analysis. For GO and the heterostructure, a little change in the ratio between the D-band and G-band was found which means that no additional defects were formed within the heterostructure.

The crystal structure and quality of ZnO thin films were enhanced by high temperature vacuum anne... more The crystal structure and quality of ZnO thin films were enhanced by high temperature vacuum annealing. High quality ZnO thin films have been grown ona-plane sapphire substrate by radio frequency (rf) magnetron sputtering method at a substrate temperature of 600C. A remarkable improvement in the epilayer quality were established by in situ high temperature annealing. The film quality, smoothness, the in plane stress, and the degree
of epitaxy of the films have been evaluated. The crystalline quality was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy analyses. An extremely smooth ZnO films were achieved at higher annealing temperatures with root mean square roughness of 0.3 nm. The transverse optical mode A1(TO) observed in all the samples and the longitudinal optical mode A1(LO) appeared only at higher annealing temperatures over 800Cin the micro-Raman scattering measurements. The strain of c-axis were relaxed and the lattice parameter was comparable to that of bulk ZnO at high annealing temperature of 900C

Recently, nano-composite solders have been developed in the electronic packaging materials indust... more Recently, nano-composite solders have been developed in the electronic packaging materials industry to improve the creep and thermo-mechanical fatigue resistance of solder joints to be used in service at high temperatures and under thermo-mechanical fatigue conditions. This paper reviews the driving force for the development of nano-composite solders in the electronic packaging industry and the research advances of the composite solders developed. The rationale for the preparation of nano-composite solders are presented at first. Examples of two nano-composite solder fabrication methods, a mechanical mixing method and an in-situ method, are explained in detail. The achievements and enhancements in the nano-composite prepared solders are summarized. The difficulties and problems existing in the fabrication of nano-composite solders are discussed. Finally, a novel nano-structure composite solder, which attempts to solve the problems encountered in the fabrication of nano-composite solders, is introduced in detail. Guidelines for the development of nano-composite solders are then provided.