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The surfaces of optoelectronic materials such as silicon, GaAs, nitrides and oxides are known to be very difficult to bond with low melting point solders (<;300°C). Small portion of active elements (3.1~4.1wt% Ti and 0.2% Ce) added into conventional SnAg solder could improve its solderability with inorganic material surfaces. In this work, some bonding experiments using active solder containing...
The composite antibacterial agents were prepared with nano-hydroxyapatite containing polyvinyl alcohol, copper ions and zinc ions via the parcels and ion exchange respectively. The as-prepared antibacterial agents were characterized by X-ray diffraction, infrared spectrogram and scanning electron microscopy. The results show that PVA has been wrapped in the surface of hydroxyapatite, and copper and...
The Vacuum interrupter is the arc extinction chamber of the vacuum circuit breaker which is widely used in the medium voltage networks for interruption of short -circuit current. In the field of vacuum switching devices, the contact material is the most important parameter determining the switching behavior. During arcing, the contacts are eroded and hence there is a change in the surface microstructure...
In order to study the growth of electrochemical migration along the thickness direction, paper/phenol-resin composite on printed wiring boards was aged at 85 °C and 85 %RH by applying of a dc voltage. Then, the sample was observed by a scanning electron microscope with a function of energy dispersive spectroscopy (SEM-EDS) analysis. Space charge distributions in the sample were also measured by the...
CuxBiySez thin films with copper concentration x up to 29 mol. % are synthesized on glass substrates by chemical-bath deposition. Films with thickness in the range of 550-597 nm are fabricated by a multiple-dip process. Deposition parameters for a single-coating run are optimized to avoid re-dissolution of the particles, and to obtain large-area composition homogeneity in the films. Routine film composition...
Ingots containing monocrystals of CuInSe2 have been fabricated, using a Bridgman-growth procedure, in quartz ampoules, to which varying concentrations of sodium and excess selenium have been added. The CuInSe2 ingots were nominally p-type, but could be made n-type by adding sufficient sodium to the melts before growth. Small additions of excess Se required that greater additions of Na be introduced...
3D ICs is a promising new technology that has many advantages over traditional planar packages. To take advantage of this technology, new bonding techniques have to be developed to satisfy the need for high density micro interconnects. Solid liquid inter-diffusion bonding in which the bond is established by placing a low melting temperature material between high temperature melting substrate and applying...
The Catalytic Wet Oxidation (CWO) method was investigated to treat wastewater from chemical container cleaning process, which contains various and high-strength pollutants. A heterogeneous catalyst was studied with Cu2+ as the active component and activated carbon as the supporter. The effects of Cu2+ concentration, calcination temperature and calcination time on the Cu-based catalyst performance...
Catalytic ozonation of p-chlorobenzoic acid (p-CBA) in aqueous solution has been carried out where transitional metal (Ni, Cu, Mn, Co, Fe) supported activated carbon was used as catalysts. Ni supported activated carbon ( Ni/AC) catalyst, which is prepared by the dipping method with an aqueous solution of Ni(NO3)2, shows higher catalytic activity. Activated carbon and Ni/AC catalyst were characterized...
Ag-Cu nanoalloy has been synthesized directly in solution. The composition, morphology and structure of the Ag-Cu nanoalloys were characterized by XRD, TEM, EDS and SEM. The morphology of Ag-Cu nanoalloys appears small, uniform, and spherical. The size distribution mainly focuses on 80nm~90nm. An average composition is Ag48.9Cu51.1, which is within experimental error of the nominal 1:1 stoichiometry...
Cuprous oxide(Cu2O)/rectorite nanocomposites were prepared through polyol method by using cupric acetate complex as precursor of Cu, aiming to utilize the iron species in the clay material and hydrogen peroxide derived from Cu2O to form a novel immobilized Fenton system. The obtained nanocomposites were characterized by X-ray diffraction, Scanning electron microscopy and X-ray Photoelectron Spectroscopy...
A new adsorbent was developed from municipal sewage sludge (SS) combined with 5-20% pyrolusite of the weight of SS carbon, and using ZnCl2 as chemical activation reagent. Characterized by N2-BET methods and SEM, the result showed that the surface area of the new adsorbent was increased to 354.198 m2/g compared with that of the unmi- xed sludge activated carbon 232.526 m2/g and total pore and micropore...
As one of the most promising lead-free solder candidates for electronics interconnection, eutectic Sn-Ag-Cu alloys are receiving increasing interest due to their merits of low melting temperature, solderability, and reliability. Meanwhile, solder bumping on wafers is of great significance for flip chip interconnection technology which requires fine-pitch, high density bonding for the demands of future...
This study describes the development of a Cu wire bond assembly solution for ICs using low dielectric constant (low K) dielectrics and Cu interconnect, with bond pads designed with aggressive BOA (Bond Over Active) design rules. The various wire bonding challenges imposed by the bond pad material stack and the aggressive high density BOA design will be discussed. It is desired to use the aggressive...
The Joule heating effect at various stages under electromigration of flip-chip Sn3.5Ag solder joints was investigated under a current of 0.5 A at 100°C. During various stages of electromigration, voids may form and propagate and Joule heating effect may vary at different void sizes. To verify the void nucleation and propagation on Joule heating effect during electromigration process, the solder bump...
In this paper, methods for high resolution analysis of the intermetallics formed in the interfaces of microelectronic packaging interconnects are discussed. The application of Transmission Electron Microscopy (TEM) in combination with energy dispersive x-ray analysis and electron diffraction for a definite identification of intermetallic compounds is compared to new approaches based on Electron Backscatter...
This investigation has achieved semi-uniform coatings of single-walled carbon nanotubes (SWNT) onto copper substrates by electrodeposition from a metallic plating bath as well as electrophoretic deposition. Furthermore, SWNT mat was used as an electrode in which metallic ions were electrodeposited. CVD-produced SWNT were functionalized via agitation concentrated sulfuric acid/nitric acid. FTIR studies...
The present paper relates to a lead-oxide-free copper thick-film paste for printing on ceramic substrates, especially on alumina. Commercialized copper thick-film pastes usually consist of copper powder with lead-oxide glass, which should be avoided in regard to the RoHS Certificate of Conformity. The screen printing technology could be an alternative method instead of the standard DCB process, particularly...
In addition to statistically relevant standard reliability tests and lifetime analysis, the study of solid-state physical degradation mechanisms for a limited number of representative samples is needed to understand weaknesses in the interconnect technology and to exclude reliability-related failure in Cu interconnects. We present dynamic studies of damage mechanisms in on-chip Cu interconnects caused...
Due to European regulations (RoHS) lead-free solder pastes have been commonly used in electronics assembly for printed wiring board (PWB) assembly in surface mount technology applications. The most popular are pastes with SnAgCu (SAC) alloy family. It is well known that some of material properties can be changed by addition of nanoparticles. Our research objective is trying to modify the lead-free...
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