Study on the Multi-Scale Properties of the Internal Structure in ACA Interconnection

Anisotropic conductive adhesives (ACAs) are widely used in microsystem packaging as interconnection materials, and many studies have been done about their electrical features, but limited works have been done on the mechanical properties with respect to the overall reliability of the packaging, and even less attention is paid to the micro-scale constituents of the internal structures in the ACA interconnection. This paper establishes a second order homogenization approach for predicting the mechanical performance of the typical internal structure in the ACA interconnection layer. This interface model is developed in the micropolar theory frame, and the macro- and micro-responses of each constituent are included. The considered structure under shear loading is simulated as application example of this model. The computational results show that the microscopic fluctuation field has a counteraction effect on the overall deformation, and the constituents with various material parameters have different responses to the prescribed loading. And the joint locations are of high possibility for crack/delamination initiation