The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Wei Sha - One of the best experts on this subject based on the ideXlab platform.
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crystallisation and phase transformation behaviour of electroless nickel phosphorus Platings during continuous heating
Journal of Alloys and Compounds, 2003Co-Authors: Z Guo, K G Keong, Wei ShaAbstract:Abstract Crystallisation process in electroless nickel phosphorus (Ni–P) Platings during continuous heating was investigated using X-ray diffraction (XRD) analysis and differential scanning calorimetry (DSC). X-ray line broadening technique was used to estimate the grain size and microstrain, with the aid of PROFIT software to separate the reflections of crystalline nickel from the amorphous phase. Results showed that in the as-deposited condition, Platings with 3–5 wt.% (NiP4), 5–8 wt.% (NiP65), and 6–9 wt.% (NiP75) phosphorus are a mixture of amorphous and microcrystalline materials, whereas the Plating with 10–14 wt.% (NiP12) phosphorus is fully amorphous. In all the Platings after continuous heating the grain size increases sharply when the temperature increases above 400 °C. The microstrain in the Platings decreases with increasing temperature. The crystalline nickel formed is largely randomly orientated. It was also shown that the NiP4 specimen heated up to the termination point of the major exothermal DSC peak at 40 °C/min has larger grain size and microstrain than that heated at 5 °C/min. The amount of Ni 3 P phase formed at this point is about the same, which indicates that the major DSC peak in the NiP4 Plating corresponds to similar transition processes regardless of the heating rate. The processes that contribute to the major exothermal peak in the DSC curve are discussed.
Yinxiang Lu - One of the best experts on this subject based on the ideXlab platform.
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improvement of copper Plating adhesion on silane modified pet film by ultrasonic assisted electroless deposition
Applied Surface Science, 2010Co-Authors: Yinxiang LuAbstract:Abstract Copper thin film on silane modified poly(ethylene terephthalate) (PET) substrate was fabricated by ultrasonic-assisted electroless deposition. The composition and topography of copper Plating PET films were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. Peel adhesion strength, as high as 16.7 N/cm, was achieved for the planting copper layer to the modified PET substrate with ultrasonic-assisted deposition; however, a relative low value as 11.9 N/cm was obtained for the sample without ultrasonic vibration by the same measurement. The electrical conductivity of Cu film was changed from 7.9 × 104 to 2.1 × 105 S/cm by using ultrasonic technique. Ultrasonic operation has the significant merits of fast deposition and formation of good membranes for electroless deposition of Cu on PET film.
Z Guo - One of the best experts on this subject based on the ideXlab platform.
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crystallisation and phase transformation behaviour of electroless nickel phosphorus Platings during continuous heating
Journal of Alloys and Compounds, 2003Co-Authors: Z Guo, K G Keong, Wei ShaAbstract:Abstract Crystallisation process in electroless nickel phosphorus (Ni–P) Platings during continuous heating was investigated using X-ray diffraction (XRD) analysis and differential scanning calorimetry (DSC). X-ray line broadening technique was used to estimate the grain size and microstrain, with the aid of PROFIT software to separate the reflections of crystalline nickel from the amorphous phase. Results showed that in the as-deposited condition, Platings with 3–5 wt.% (NiP4), 5–8 wt.% (NiP65), and 6–9 wt.% (NiP75) phosphorus are a mixture of amorphous and microcrystalline materials, whereas the Plating with 10–14 wt.% (NiP12) phosphorus is fully amorphous. In all the Platings after continuous heating the grain size increases sharply when the temperature increases above 400 °C. The microstrain in the Platings decreases with increasing temperature. The crystalline nickel formed is largely randomly orientated. It was also shown that the NiP4 specimen heated up to the termination point of the major exothermal DSC peak at 40 °C/min has larger grain size and microstrain than that heated at 5 °C/min. The amount of Ni 3 P phase formed at this point is about the same, which indicates that the major DSC peak in the NiP4 Plating corresponds to similar transition processes regardless of the heating rate. The processes that contribute to the major exothermal peak in the DSC curve are discussed.
Jian Ku Shang - One of the best experts on this subject based on the ideXlab platform.
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solderability of electrodeposited fe ni alloys with eutectic snagcu solder
Journal of Materials Science & Technology, 2007Co-Authors: Lei Zhang, Aiping Xian, Jian Ku ShangAbstract:Solderabilities of electrodeposited Fe-Ni alloys with SnAgCu solder were examined by wetting balance measurements and compared to those of pure Ni and pure Fe Platings. Excellent solderability was found on the Ni-52Fe Plating as both the wetting force and kinetics approached or exceeded those on the pure Ni. However, upon further increase in Fe content to 75 at. pct, the solderability of the alloy was severely degraded even though it was still better than that of the pure Fe Plating. X-ray photoelectron spectroscopy showed that such a strong dependence of solderability on Fe content is related to the much thinner, incomplete oxide coverage of Ni-rich Plating surface.
Chengen Ho - One of the best experts on this subject based on the ideXlab platform.
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high speed cu electrodeposition and its solderability
Surface & Coatings Technology, 2017Co-Authors: Yingsyuan Wu, Chih Chen, W Z Hsieh, Chengen HoAbstract:Abstract The effects of the Plating current density ( j ) on the electroplated Cu microstructure, impurity distribution, and the solderability of the electroplated Cu were investigated. Analyses of electron backscatter diffraction and transmission electron microscopy showed that the Cu grain size ( D ) decreased from microscale to submicron-scale, and the predominant crystallographic orientation translated from [111]||ND + [101]||ND into [101]||ND (ND: Cu deposition direction) with increasing j . Time-of-flight secondary ion mass spectrometry analysis showed that the impurity content in the Cu Platings (especially the Cl content) increased as a function of j . These investigations showed that j posed a significant influence on the characteristics of the electroplated Cu. Two intermetallic compound (IMC) species (η-Cu 6 Sn 5 and Cu 3 Sn) accompanied with some material defects (e.g., nanovoids and microcracks) formed at the solder/Cu pillar interface after reflow. The IMC (Cu 6 Sn 5 ) growth morphology and orientation, and the defect distribution were also strongly j -dependent. These j -dependent interfacial microstructures were closely related to different D and impurity contents of the Cu Platings. The results of this study advanced our understanding of the effects of j on electrochemical metal deposition, and they were helpful in the development of the high-speed Cu electrodeposition technology.
