Thermal curing of adhesive films was investigated to facilitate the fabrication of a reliable bonding for semiconductors. The formulated adhesive films contained acrylic polymer, epoxy resins, phenol resin, and an imidazole derivative that was the catalyst for curing the epoxy resins with phenol resin. The solubility, thermally latent characteristics, mechanical and adhesive properties of 2-methylimidazole/boron trifluoride (2MZ/BF3), and 2MZ/aluminum trisacetylacetonate (AlAC) were investigated. It was found that 2MZ/BF3 and 2MZ/AlAC had excellent solubility in adhesive materials and they had excellent latent characteristics as thermal curing catalysts for epoxy resins, whereas conventional catalysts (2MZ and 2-phenyl-4, 5-dihydroxymethylimidazole (2PHZ)) could not achieve both excellent solubility and thermally latent characteristics. The mechanical and adhesive properties of the post-thermal-cured adhesive film that contained 2MZ/BF3 or 2MZ/AlAC were comparable to those of the postthermal-cured adhesive films that contained conventional catalysts. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 298-303, 2009