Interfacial Reaction of Sn-Ag-Cu Lead-Free Solder Alloy on Cu: A Review

This paper reviews the function and importance of Sn-Ag-Cu solder alloys in electronics industry and the interfacial reaction of Sn-Ag-Cu/Cu solder joint at various solder forms and solder reflow conditions. The Sn-Ag-Cu solder alloys are examined in bulk and in thin film. It then examines the effect of soldering conditions to the formation of intermetallic compounds such as Cu substrate selection, structural phases, morphology evolution, the growth kinetics, temperature and time is also discussed. Sn-Ag-Cu lead-free solder alloys are the most promising candidate for the replacement of Sn-Pb solders in modern microelectronic technology. Sn-Ag-Cu solders could possibly be considered and adapted in miniaturization technologies. Therefore, this paper should be of great interest to a large selection of electronics interconnect materials, reliability, processes, and assembly community

Chitosan–ammonium acetate–ethylene carbonate membrane for proton batteries

AbstractProton-conducting membranes were prepared using a solution-casting technique. The highest membrane conductivity of (3.83±0.73)×10−3Scm−1 was achieved in chitosan acetate–50wt.% ammonium acetate–70wt.% ethylene carbonate. The batteries were fabricated with a configuration of Zn+ZnSO4·7H2O‖chitosan membrane‖MnO2 and Zn+ZnSO4·7H2O‖chitosan membrane‖V2O5. The cathode materials produced open circuit voltages of 1.60 and 1.27V using manganese (IV) oxide (MnO2) and vanadium (IV) oxide (V2O5), respectively. The discharge capacities of the batteries were 45.0 and 34.7mAh using MnO2 and V2O5 cathode at 1.0mA, respectively. The maximum power densities were 1.83mWcm−2 for the battery with MnO2 and 1.36mWcm−2 for the battery with V2O5 cathode

A review on the self energize structural health monitoring (SHM) in vertical axis wind turbine (VAWT) system

Wind energy is one of the renewable energy sources which the trend is positive and increasing year by year. This technology applied widely in several regions in the world and already has maturity in technology, good infrastructure and relative cost competitiveness. The application of structural health monitoring (SHM) is crucial especially to evaluate the performance of wind turbine in real time assessment. Furthermore, the smart material in SHM can be utilized as micro energy harvester as well. However, the application of SHM and micro energy harvester for wind turbine is still premature especially in SHM embedded or bonded strategy. Several issues are highlighted such as SHM material selection, wind turbine selection and the issue in micro energy harvester. The issues are discussed and compared with the recent finding in this review. Several recommendations are suggested for future study especially on the application of micro energy harverster

Particle tracking analysis of river-aquifer interaction via bank infiltration techniques

Induced bank infiltration (BI) is commonly implemented in other countries, but remains new and unexplored in Malaysia. Increasing river pollution could affect drinking water resources. Given the threat of pollution to raw water sources, applying induced BI to sustain water management is essential. This paper presents a case study of the BI method, which evaluates the effects of groundwater pumping and BI operation on the installation of wells as well as determines the effect of pumping rate on flow paths, travel time, the size of the pumping and capture zone delineation, and groundwater mixing in a pumping well in Jenderam Hilir, Malaysia. The proposed method performs infiltration safely and achieves the ideal pumping rate. Numerical modeling packages, MODFLOW and MODPATH (particle tracking) were used. Results indicate that the migration of river water into the aquifer is generally slow and depends on the pumping rate and distance from well to the river. Most water arrives at the well by the end of a pumping period of 1–5 days at 3,072 m3/day for test wells DW1 and DW2, and during simultaneous pumping for DW2 and PW1 for a well located 36 and 18 m, respectively, from the river. During the 9.7-day pumping period, 33 % of the water pumped from the DW1 well was river water, and 38 % from DW2 throughout 4.6 days was river water. The models provide necessary information for water operators in the design and construction of pumping and sampling schedules of BI practices

Recent Characterisation of Sol-Gel Synthesised TiO2 Nanoparticles

High demand and current applications have led to continuous study and subsequent improvement of TiO2 nanoparticles. The versatility of the sol-gel method allows employing different process parameters to influence the resultant properties of TiO2 nanoparticles. The evaluation and characterisation process of the synthesised TiO2 nanoparticles commonly involves a series of methods and techniques. Such characterisation methods include phase, structural, morphology and size analysis. A combination of data from these evaluations provides the relationship between the synthesis parameters and the end properties of TiO2 nanoparticles. Apart from the research findings on TiO2 nanoparticles, the characterisation used to obtain these findings is equally important. Thus, this chapter highlights the recent characterisation techniques and practices employed for TiO2 nanoparticles synthesised by the sol-gel method

Effect of TiO2 Nanoparticles on the Horizontal Hardness Properties of Sn-3.0Ag-0.5Cu-1.0TiO2 Composite Solder

The improvement in the hardness of Sn-3.0Ag-0.5Cu solder alloy reinforced with 1.0 wt. % TiO2 nanoparticles was evaluated by nanoindentation. A specific indentation array was performed on four different horizontal cross sections of the composite solder with different heights and diameters, in order to verify the mixing homogeneity of TiO2 nanoparticles within the Sn-3.0Ag-0.5Cu solder paste during the ball milling process. The phase analysis indicated successful blending of the Sn-3.0Ag-0.5Cu with the TiO2 nanoparticles. According the scanning electron microscopy micrographs, presence of the TiO2 nanoparticles reduced the size of the Cu6Sn5 and Ag3Sn intermetallic compound phases. Incorporation of the 1.0 wt. % TiO2 nanoparticles improved the hardness values up to 26.2 % than that of pure SAC305. The hardness values increased gradually from the top cross sections towards adjacent to the solder/substrate interface. The mechanism of the hardness improvement attained by the TiO2 nanoparticles addition were also investigated on the horizontal cross sections of the samples

Using particle tracking as a tool sustainable bank infiltration techniques: a case study in an alluvial area

This study was inspired by the Klang Valley water crisis, for which bank infiltration (BI) is considered a potential solution. This paper presents a case study of the BI techniques, which evaluates the effects of groundwater pumping and BI operation on the installation of wells. This study also determines the effect of pumping rate on flow paths, travel time, the size of the pumping and capture zone delineation, and groundwater mixing in a pumping well in Jenderam Hilir, Malaysia. The proposed method performs infiltration safely and achieves the ideal pumping rate. Numerical modeling packages, MODFLOW and MODPATH (particle tracking) were used. Results indicate that the migration of river water into the aquifer is generally slow and depends on the pumping rate and distance from well to the river. Most water arrives at the well by the end of a pumping period of 1 to 5 days at 3,072 m3/day for test wells DW1 and DW2, and during simultaneous pumping for DW2 and PW1 for a well located 36 and 18 m, respectively, from the river. During the 9.7-day pumping period, 33 % of the water pumped from the DW1 well was river water, and 38 % of the water pumped from DW2 throughout 4.6 days was river water