A conductive adhesive is a promising interconnection material for microsystem packaging. The interconnect features are of great importance to system responses under various loading conditions. The flip-chip packaging system with anisotropic conductive film (ACF) joint under thermal loadings has been investigated both experimentally and theoretically. The displacement distributions have been measured by an interferometer, which could provide the in-plane whole-field deformation observation. The interconnection is of much smaller scales compared with the neighbouring components such as the chip and substrate, and there are even finer internal structures involved in the joint. The wide scale range makes both experimental observation and conventional simulation difficult. A micropolar model is thus developed. Utilizing the homogenization, this model requires low computation resource. Combination of this model with a second-order model was able to produce a highly efficient and valid prediction of the packaging system response under thermal and mechanical loadings. Comparison of the micropolar model simulation and experimental data shows good agreement. (c) Koninklijke Brill NV, Leiden, 2008