This paper describes the effect of polyhedral oligomeric silsesquioxane (POSS) in anisotropic conductive films (ACFs) composition on the material properties and reliability of ACF interconnections for chip-on-glass (COG) applications. Series of POSS modified ACFs containing 0wt%, 2wt%, 4wt%, 6wt% and 8wt% contents of octa-methacrylated POSS were formulated and characterized. The POSS added in the formulations favorably affected on the materials properties of ACFs by lowering coefficient of thermal expansion (CTE) and increasing modulus (E'). In addition, an increase in the POSS contents led to higher curing density and, as a result, thermo-mechanical properties of ACFs were improved. But, the adhesion strength of ACF materials was decreased with the POSS content, due to higher modulus originated from octa-functional POSS. The reliability performances of COG assemblies using POSS modified ACFs were also investigated. In conclusion, the materials properties and module reliability of COG assemblies were improved with increasing POSS content in ACFs.