Design, Fabrication and Characterization of Lead-Free Nano-Composite Solder Sn-Ag-Cu/ CeO2

, Ph.D. Dissertation Sharif University of Technology Roshanghias, Ali (Author) ; Kokabi, Amir Hossein (Supervisor) ; Madaah Hosseini, Hamid Reza (Supervisor)

Abstract

As one of the key technologies for high performance electronic devices, composite solders have been recently developed to improve thermal and mechanical properties of solder joints. In this study, accumulative roll bonding (ARB) process was used as an effective alternative method for manufacturing high-strength, ﬁnely dispersed, void-free and highly uniform Sn-Ag-Cu/CeO2 nanocomposite solders. Microstructural investigation of nanocomposite solders revealed that homogenous distribution of CeO2 nanoparticle has been achieved and the eutectic as-cast morphology of the solder changed to recrystallized fine grained structure. As a result of severe plastic deformation during rolling, brittle and...

An Investigation into the Production and Properties of Lead-Free Solder Alloy Sn-3.5Ag

, M.Sc. Thesis Sharif University of Technology Ghadi, Saman (Author) ; Karimi Taheri, Ali (Supervisor)

Abstract

This study was conducted in order to investigate on production and propeties of lead free solder alloy. For this purpose, Sn-Ag alloy with 3.5 weight percent of silver and sn-3.5Ag-0.7Cu at eutectic composition were produced with casting procedure.Single-lap Specimens were used to simulate real solder joints with the solder reflowed between two pure Cu substrate.Microstructural characterization, electrical resistance measurements and shear-tension test were performed.A deacrease of electrical resistance was observed in produced alloys in comparison with Sn-Pb . Experimental results showed that mechanical properties of produced alloys was better than common pb content alloy.The effect of...

Effect of Constraint on Fracture Energy and Fracture Load Prediction of Solder Joints

, M.Sc. Thesis Sharif University of Technology Mirmehdi, Sadegh (Author) ; Farrahi, Gholamhossein (Supervisor)

Abstract

Mode І critical strain energy release rate at crack initiation, Jci, of SAC305 solder joints between two copper substrates was measured using double cantilever beam (DCB) specimens at a strain rate of 0.03 s-1 as a function of bond-line width (i.e. joint size in the out-of-plane dimension), solder thickness, copper adherends thickness and suface roughness. Fracture force per unit width and Jci were relatively insensitive to width of the joint ranging from 8 to 21 mm. Variations in solder thickness (i.e. 150 µm, 250 µm and 450 µm) also had an insignificant influence on the fracture energy of solder joints. This behavior was explained in terms of stress distribution, plastic zone area and...