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Worldwide, urban air pollution is a serious health and environment concern in our major cities. Road transport, particularly that using diesel vehicles, is generally the major contributor to the declining air quality in urban areas. This has provoked increasingly stringent vehicle emission standards worldwide and stimulated research into alternative fuels and technologies that promise cleaner and lower emissions. The use of alternative fuels for engine is regarded as one of the major research areas for the age [1-3]. In the

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Citation: Yasmin T, Sadiq M, Khan MI (2014) Effect of Lanthanum Doping on the Microstructure Evolution and Intermetallic Compound (IMC) Growth during Thermal Aging of SAC305 Solder Alloy. J Material Sci Eng 3: 141. SAC305Among the various lead-free solders SAC-305 alloy has emerged as the most widely accepted to replace Sn-Pb solders. It is widely used as lead-free solder for surface mount technology (SMT) card assembly and for ball-grid-array (BGA) interconnection in the microelectronic packaging industry as solder balls and pastes. More than 70% market for reflowing lead-free solders are in the SAC series. Due to having good mechanical properties, acceptable wetting properties, and suitable melting points, the International Printed Circuit Association has suggested that SAC-305 and SAC-396 will be the most widely used alloys in the future [10][11][12][13][14][15][16].Although SAC-305 alloy is widely used in electronics industry, it has several problems to be solved. One of the core issues pertaining to Abstract Sn96.5Ag3Cu0.5 (SAC305) is widely used as lead-free solder for surface mount technology (SMT) card assembly and for ball-grid-array (BGA) interconnection in the microelectronic packaging industry as solder balls and pastes. In this study the effects of Lanthanum (La) doping on SAC305 under thermal aging was investigated as function of intermetallic compounds (IMCs) growth and grain size evolution. The morphology of the microstructure was analyzed under Scanning Electron Microscope (SEM) and optical microscope, the elemental distribution was confirmed by Energy Dispersive Spectroscopy (EDS) and phase identification of the crystalline structure formed during thermal aging was confirmed by x-ray diffraction (XRD). It was found that the microstructure of SAC305 solder alloy changes significantly with addition of La. Quantitative analysis of grain size and intermetallic particle size was performed both for undoped and La-doped SAC305 alloys.The XRD and EDS tests found that the doping elements La exist in SAC305 solder alloy in two forms: as La element or as La5Sn3 IMC.The La-Sn IMC has complex branch structure [89], which is usually look like clusters of snowflakes [57] in SEM images. With the help of EDX analysis very high amount of La concentration of observed in these snowflakes. Moreover It was also observed that quantity La5Sn3 IMC depend upon the concentration La doping i.e. with high 0.5wt% of lanthanum bigger snowflakes has be observed as shown in Figure 8 while small isolated snow can be seen with less La doping which is consistent with the results of Min et al [25].La doping greatly reduces the Ag 3 Sn and Cu 6 Sn 5 particle size particle during thermal aging. Surface area averaged particle size of Cu 6 Sn 5 particles was obtained as per ASM handbook [95]. The particle sizes for the full data set are plotted in Figure 9 as function of La doping level. It can be seen that La doping effectively suppresses the growth of Ag 3 Sn and Cu 6 Sn 5 intermetallic particle.