Temperature dependence of mechanical properties of isotropic conductive adhesive filled with metal coated polymer spheres

An isotropic conductive adhesive (ICA) filled with metal-coated polymer spheres (MPS) has been studied as a novel approach to increase the flexibility, and hence the reliability, compared to the conventional metal-filled ICA. In this study, the effect of the metal coating on the die shear strength was investigated by comparing ICA materials with coated and uncoated polymer spheres. The other important part of the study was to assess the temperature dependence of the die shear strength of an MPS-based ICA, and also compare this with the behavior of a conventional ICA filled with Ag particles. The results showed that the metal coating does not have a critical effect on the die shear strength of ICA filled with MPS. The die shear strengths obtained for the MPS-based ICA and the conventional Ag-filled ICA have the same temperature dependence in the range of 20°C to 120°C. Furthermore, none of the ICA systems has experienced a critical drop in die shear strength at and above the glass transition temperature.