Mechanical characterization of SiLK by nanoindentation and substrate curvature techniques

\u3cp\u3eAdvanced micro mechanical characterization methods provide material properties of thin films for modelling thermo mechanical behavior of thin films for microelectronic applications. Here we focus on the local measurement method of nanoindentation for finding visco-elastic properties, and a global method of substrate curvature testing that provides linear elastic properties. Our specimen SiLK, Dow Chemicals, is a thin polymer film with a thickness in 400nm and 8micron, deposited on Si substrate. Our results show temperature dependent linear elastic and linear visco-elastic material properties for thin film materials.\u3c/p\u3

Investigation on thermal properties of crosslinked epoxy resin by MD simulation

Behavior of epoxy resin is critical for performanceand reliability of electronic packages. The ability topredict properties of cross linked epoxy resin prior tolaboratory synthesis will facilitate the materials design. Theoretical studies in this field face a big challenge because there is no conventional way to build atomistic models of specific polymers, which form a network. Molecular dynamics (MD) is a potentially powerful method that can simulate the materials at atomic scale and it can be used to describe the performance and properties of a wide range of systems. In the present work, the properties of the cross-linked epoxy resin compound were predicted by MD simulations. Periodic amorphous structures of the cross-linked epoxy resincompound were simulated at various temperatures. Thecorrelation of the glass transition temperature (Tg) and properties of the cross-linked epoxy resin compoundwere investigated. The results show that Tg can beestimated by the plot of densities and non-bond energyat different temperatures. The Tg predicted was inagreement with the experimental data, which showsthat MD simulation is an effective tool to estimate theproperties of crosslinked epoxy resin

Effect of chain flexibility in the network structure on the viscoelasticity of epoxy thermosets

In this paper a detailed study in investigating the effect of the chain flexibility in epoxy-amine crosslinked network is done. In order to introduce flexibility into the crosslinked network a homologous series of four aliphatic diamine curing agents varying only in the chain length and having a constant functionality (f?=?4) is taken and cured stoichiometrically with aromatic epoxy (f?=?2) resin. For each of the cured mixture the viscoelastic master curve and corresponding shift factors were determined. It is found the introduction of flexibility shifts the viscoelastic curves by 5 decades with respect to frequency scale. This shift in the viscoelastic curve is modeled with a parameterized Havriliak-Negami model for the master curve. The free volume contribution for the changes in the coefficient of thermal expansion at T g is also determined.Precision and Microsystems EngineeringMechanical, Maritime and Materials Engineerin