Interfacial compatibility of polymer-based structures in electronics

摘要

Interfacial compatibility of dissimilar materials was investigated to achieve a better understanding of interfacial adhesion in metal/polymer/metal systems. Surface modifications of polymers were applied to improve the adhesion. The modified surfaces were characterised by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contact angle measurements accompanied by surface free energy evaluations. The pull-off test was employed to assess the interfacial adhesion strength. Further, to determine the controlling adhesion mechanism, the fracture surfaces exposed in the pull-off test were examined by microscopy. To achieve modification of certain bulk properties of one of the evaluated polymers (SU8 epoxy resin), new star-shaped oligomers were synthesised and reactively blended with it. Oligomers were characterised by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, size exclusion chromatography (SEC) and differential scanning calorimetry (DSC). Films of the blends were spin coated on a silicon wafer for characterisation of the refractive index and a novel non-destructive method was developed to measure selected thermal properties of the films. The information concerning interfacial compatibility obtained in this work is of great practical as well as theoretical importance.