Lead-free soldering, originally started as an environmental issue, is evolving rapidly into a business survival tool for the worldwide electronic industry. Promising lead-free solder alternatives for surface mount assembly applications include eutectic Sn/Ag, eutectic Sn/Cu, Sn95/Sb5, eutectic Sn/Bi, Sn/Ag/Cu, Sn/Ag/Cu/X, Sn/Bi/Ag/X, Sn/Zn/X, and Sn/In/Ag/(X). However, for wafer level area arra...

Kesterite based materials are being researched and developed as affordable, efficient, mechanically flexible absorber for thin film photovoltaics. Both (Ag,Cu) 2 ZnSnSe 4 Cu Zn(Sn,Ge)Se devices have shown great potential in overcoming some of the remaining challenges further increasing conversion efficiency kesterite solar cells. This study therefore investigates long range crystallographic str...

Effect of holding time and temperature on the fatigue life of micro Sn-Ag-Cu solder joint has been studied with waveform of triangle and trapezoid wave at 298K and 398K. Both the microstructural coarsening and the crack propagation occurred simultaneously and therefore the cyclic load decreased rapidly in the trapezoidal wave at 398K compared with the other conditions. Therefore, under the cond...

The problem of a steady boundary layer shear flow over a stretching/shrinking sheet in a nanofluid is studied numerically. The governing partial differential equations are transformed into ordinary differential equations using a similarity transformation, before being solved numerically by a Runge-Kutta-Fehlberg method with shooting technique. Two types of nanofluids, namely, Cu-water and Ag-wa...

We report the influence of growth rate and external magnetic field on the eutectic lamellar spacing and properties of directionally-solidified Ag-Cu eutectic alloys. The results indicated that the relationship between the lamellar spacing of directionally-solidified Ag-Cu alloys and the growth rate matched the prediction of the Jackson-Hunt model, and the constant was 5.8 µm³/s. The increasing ...

A very simple method for synthesizing nanosize-controllable (4–40 nm) metals (Cu, Ag, Pd, Rh and Ni) or alloys within carbon shells has been developed. The thickness of the carbon shell that prevents the core metals from being aggregated or oxidized ranges from 3–5 nm. In addition, the synthesized metal nanoparticles exhibit a correlation between dpZ/R (Z = valence of metal and R = atomic radiu...

Activities of the components binary lead-free solder alloys Cu-Sn, and Ag-Cu were computed using molecular interaction volume model (MIVM). The theoretical data have been compared with corresponding experimental values. For validity parameters, excess Gibbs free energy mixing liquid determined available in literature. Similarly, activities Sn ternary Sn-Ag-Cu examined at 1000 K. It has observed...

Using ligands based on either an acetylacetonate or a dipyrrin moiety appended with pyridyl groups, a series of novel heteroleptic copper(II) and cobalt(III) complexes combining both chelate units such as (acacpy(2))Cu(dpm-py) and (acacpy(2))Co(dpm-py)(2) (acacpy(2) = 1,3-bis(4-pyridyl)-1,3-propanedionate; dpm-py = 5-(4-pyridyl)dipyrrin) have been prepared and fully characterized. These two com...

Abstract: Chalcopyrite and bornite are two important copper minerals, and they often coexist. In this study, the co-bioleaching of chalcopyrite and silver-bearing bornite by mixed moderately thermophilic culture at 50 ◦C was investigated. The bioleaching results show that the extraction percentage of Cu for co-bioleaching of chalcopyrite (Ccp) and silver-bearing bornite (Bn) (Ccp/Bn = 3:1) was ...

Binding of Cu(2+), Ni(2+) and Ag(+) ions to polyallylamine (PAA), polyethylenimine (PEI), poly(N-2-(2-pyridyl)ethylallylamine) (PEPAA), poly(N-2-(2-pyridyl)ethylethylenimine) (PEPEI), and N-2-(2-pyridyl)ethylchitosan (PEC) has been investigated using batch sorption experiments, spectrophotometric titration, ESR, and XPS to elucidate how the structure of polymer precursors affects the ion bindin...