Solderability of Sn-0.7Cu/Si3N4 lead-free composite solder on Cu-substrate

AbstractReinforcing high performance ceramic particulates is an effective approach to improve solderability of lead-free Sn-0.7Cu solder. Various weight percentage compositions (0.5, 1.0, and 1.5) of Silicon Nitride (Si3N4) reinforced in Sn-0.7Cu solder were developed using powder metallurgy (PM) routes to investigate their solderability properties on copper (Cu) substrate. The solderability performances of the new composite solder will be determined and analyzed based on their contact angles on Cu substrate, including interface intermetallic compound (IMC) layer thickness and IMC phases formed for different Si3N4 ratios. Results also show an improvement in solderability of the Sn-0.7Cu/Si3N4 composite lead-free solder with optimum wettability achieved by 1.0wt.% Si3N4. The minimal average decrease in IMC layer thickness and the formation of the different shaped of scallops figuring the IMC layer were observed. X-ray diffraction (XRD) also revealed the decreasing peak intensity of Cu6Sn5 phases with Si3N4. Overall, the entire range of composition of Si3N4 into Sn-0.7Cu monolithic solder use in this study indicated an enhancement of solderability performances on Cu-substrates

An optimization approach for predictive-reactive job shop scheduling of reconfigurable manufacturing systems

The manufacturing industry is now moving forward rapidly towards reconfigurability and reliability to meet the hard-topredict global business market, especially job-shop production. However, even if there is a properly planned schedule for production, and there is also a technique for scheduling in Reconfigurable Manufacturing System (RMS) but job-shop production will always come out with errors and disruption due to complex and uncertainty happening during the production process, hence fail to fulfil the due-date requirements. This study proposes a generic control strategy for piloting the implementation of a complex scheduling challenge in an RMS. This study is aimed to formulate an optimization-based algorithm with a simulation tool to reduce the throughput time of complex RMS, which can comply with complex product allocations and flexible routings of the system. The predictive-reactive strategy was investigated, in which Genetic Algorithm (GA) and dispatching rules were used for predictive scheduling and reactivity controls. The results showed that the proposed optimization-based algorithm had successfully reduced the throughput time of the system. In this case, the effectiveness and reliability of RMS are increased by combining the simulation with the optimization algorithm

Effect of kaolin geopolymer ceramic addition on the properties of Sn-3.0Ag-0.5Cu solder joint

This paper investigates the effects of different weight percentages (0, 0.5, 1.0, 1.5 and 2.0 wt.%) of kaolin geopolymer ceramic (KGC) on the microstructure formation, thermal properties, spreadability and joint strength in Sn-3.0Ag-0.5Cu (SAC305) lead-free solder alloys in order to develop a new composite solder system. Advanced characterization techniques such as Electron backscatter diffraction (EBSD) and synchrotron micro-XRF were used to study the behaviors of the pure SAC305 and KGC reinforced SAC305 composite solders. Experimental results shows that the addition of KGC refines the β-Sn area and increases the eutectic area with fine intermetallics formation. In addition, the thickness of the IMC layer is reduced with a reduction in undercooling value for the KGC reinforced SAC305 composite solder. The spreadability of the KGC reinforced SAC305 composite solder is significantly increased in the spreadable area with a higher strength of solder joint. Significantly, the results obtained prove that 1.0 wt.% KGC addition gives better performance in terms of microstructure formation, thermal properties, spreadability and joint strength. Synchrotron micro-XRF interestingly indicated that some Al and Si, which are the major elements in geopolymer systems, migrate into the solder area

Influence of Activated Carbon Particles on Intermetallic Compound Growth Mechanism in Sn-Cu-Ni Composite Solder

The influence of Activated Carbon (AC) particles on mechanical properties of Sn-Cu-Ni-xAC solder joint was investigated. Five different Activated Carbon (AC) percentage addition (0 wt. %, 0.25 wt. %, 0.5 wt. %, 0.75 wt. %, and 1.0 wt. %) were prepared via powder metallurgy (PM) technique. Interfacial IMC thickness measurement and shear strength results showed that with thinner IMC layer (by increasing amount of wt.% of AC), the higher the shear strength of the joint. It is believed that the AC particles suppresses the interfacial IMC growth and thus improves the shear strength

Influence of Activated Carbon Particles on Intermetallic Compound Growth Mechanism in Sn-Cu-Ni Composite Solder

The influence of Activated Carbon (AC) particles on mechanical properties of Sn-Cu-Ni-xAC solder joint was investigated. Five different Activated Carbon (AC) percentage addition (0 wt. %, 0.25 wt. %, 0.5 wt. %, 0.75 wt. %, and 1.0 wt. %) were prepared via powder metallurgy (PM) technique. Interfacial IMC thickness measurement and shear strength results showed that with thinner IMC layer (by increasing amount of wt.% of AC), the higher the shear strength of the joint. It is believed that the AC particles suppresses the interfacial IMC growth and thus improves the shear strength

Relationship between free solder thickness to the solderability of Sn–0.7Cu–0.05Ni solder coating during soldering

The relationships between solderability, free solder thickness and intermetallic thickness of Sn–0.7Cu–0.05Ni solder coatings on Cu substrate has been investigated. The annealing method was proposed to control free solder thickness by controlling the ratio of free solder and interfacial intermetallics (IMCs). The solderability of solder coating has investigated using a purpose-designed microwetting balance. The interfacial intermetallic microstructure was analysed and the thickness measured in the as-coated condition with aging process. Results indicate that the solderability is related to free solder thickness, where the increase of aging time and temperature thickness of the free solder is reduced by the interfacial intermetallic compound growth. Onwards, the different composition of germanium (Ge) was added into Sn–0.7Cu–0.05Ni as an antioxidant to control drossing of the molten solder. The effect on solderability of a Ge addition to the coating alloy was measured. These results may be used as a basis to obtain an optimum wettability of solder coating during soldering