Anisotropic conductive adhesives with enhanced thermal conductivity for flip chip applications

In this paper, we present the development work of anisotropic conductive adhesives (ACA) with particular emphasis on the enhanced thermal conductivity of ACAs for flip chip applications. To ensure good thermal conductivity, we incorporated silicon carbide (SiC) fillers in the ACA formulation. For the characterization of modified ACAs with enhanced thermal conductivity by loading different content of SiC fillers, measurements of thermal conductivity and thermomechanical analyses such as dynamic scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermomechanical analysis (TMA) were performed. The current carrying capability and reliability of flip chip joints using conventional ACA and novel ACA with enhanced thermal conductivity were compared to investigate the role of ACA as a new thermal transfer medium in the flip chip assembly. We developed a new ACA with high thermal conductivity which can improve reliability under high current stressing. This paper is part of a broad study of thermally conductive ACAs for flip chip packaging and other electronic packaging technologies.