Interface Modelling of ACA Interconnects Using Micropolar Theory

The contribution focuses on applying micropolar theory which, as compared to the classical continuum theory, can offer the possibility to include e.g. a microstructural size-effect for the simulation and prediction of the interfacial stresses of microsystem interconnections, such as anisotropically conductive adhesives. As the dimension of the adhesive is much smaller than the chip or the substrate, it is treated as an interface zone with a finite thickness. The micro-polar theory is used in the vicinity of the interface to model the transfer of the couple stress across the interface, and a degenerated micropolar continuum to model the interface, across which a displacement and a rotational jump is regularized. The paper is concluded by a numerical example involving the FE-representation of the interface formulation