1,721,010 research outputs found
Prediction of primary intermetallic compound formation during interfacial reaction between Sn-based solder and Ni substrate
No full textBy comparing the activation energy for nucleation of individual intermetallic compound (IMC), the IMC phase that forms first is predicted as the one with the smallest activation energy. This methodology has been successfully applied to observations of IMC phases that form during liquid soldering on Cu and Ni plates. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved
Effect of soldering and aging time on interfacial microstructure and growth of intermetallic compounds between Sn-3.5Ag solder alloy and Cu substrate
No full textThe formation and the growth of the intermetallic compound (IMC, hereafter) at the interface between the Sn-3.5Ag (numbers are all in wt.% unless otherwise specified) solder alloy and the Cu substrate were investigated. Solder joints were prepared by changing the soldering time at 250 degrees C from 30 sec to 10 h and the morphological change of IMCs with soldering time was observed. It resulted from the competition between the growth of IMC and the dissolution of Cu from the substrate and IMCs. They were further aged at 130 degrees C up to 800 h. During aging, the columnar morphology of IMCs changed to a more planar type while the scallop morphology remained unchanged. It was observed that the growth behavior of IMCs was closely related with the initial soldering condition
Solder Alloy Design and Interfacial Reaction at the Interconnection in the Electronic Packaging
No full textElectron transport in high quality undoped ZnO film grown by plasma-assisted molecular beam epitaxy
No full textHigh quality ZnO films were grown on c-plane sapphire substrate using low temperature ZnO buffer layer by plasma-assisted molecular beam epitaxy. The film deposited at 720 degrees C showed the lowest value of full-width at half maximum for the symmetric (0002) diffraction peak of about 86 arcsec. The highest electron mobility in the films was about 103-105 cm(2)/V s. From temperature-dependent Hall effect measurements, the mobility strongly depends on the dislocation density at low temperature region and the polar optical phonon scattering at high temperature, respectively. Moreover, by obtaining the activation energy of the shallow donors, it was supposed that hydrogen was source of n-type conductivity in as-grown ZnO films. (c) 2006 Elsevier Ltd. All rights reserved
Calculation of surface tension and wetting properties of Sn-based solder alloys
No full textThis study has been supported by the Minstry of Science and Technology (MOST) through the Center for Interface Science and Engineering of Materials (CISEM
Relationship between domain structure and film thickness in epitaxial PbTiO3 films deposited on Mg(001) by reactive sputtering
No full textThe epitaxial PbTiO3 thin films of different thickness were prepared on MgO(001) substrates by the reactive direct-current magnetron sputtering. The volume fraction of c domains, alpha, which was measured by x-ray diffractometry, increased rapidly from zero with the film thickness, being saturated at about 90% above 100 nm. The films were annealed in a PbO atmosphere at 700 degrees C for 8 h, and they were used to study the composition change in the Pb/(Pb + Ti) ratio and the relaxation of the residual intrinsic stress. The relationship between change of alpha and composition was weak. The stress state was calculated through the finite-element method. As for the small thickness, the tensile epitaxial stress overwhelmed compressive intrinsic and thermal stresses, and the domain structure was a-domain oriented. As for the large thickness, the compressive intrinsic stress together with the thermal stress overcame the tensile epitaxial stress, and the population turned into c domain
Prediction of Bond Strength and Thermal Fatigue Characteristic of Plasma Sprayed Thermal Barrier Coatings by Finite Element Method
No full textInterfacial microstructure and joint strength of Sn-3.5Ag-X (X = Cu, In, Ni) solder joint
No full textInterfacial phase and microstructure, solder hardness. and joint strength of Sn-3.5Ag-X (X = Cu. In, Ni; compositions are all in wt% unless specified otherwise) solder alloys were investigated. Considering the melting behavior and the mechanical properties, five compositions of Sn-3.5Ag-X solder alloys were selected. To examine the joint characteristics, they were soldered on under bump metallurgy isothermally at 250 degreesC for 60 s. Aging and thermal cycling (T/C) were also performed on the solder joint. The interfacial microstructure of the joint was observed by scanning electron microscopy. X-ray diffraction and energy dispersive x-ray analyses were made to identify the type of solder phase and to measure compositions. Excessive growth of an inter-facial intermetallic layer in the Sn-3.5Ag-6.5 In solder joint led to a brittle fracture. In the other four solder joints, ductile fractures occurred through the solder region and the solder hardness was closely related with the joint strength.This study has been supported by the Center for Electronic Packaging Materials (CEPM) of the Korea Science and Engineering Foundation (KOSEF)
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