Insulating films for hand-held phone printed circuit boards (HHP PCBs) were manufactured from a variety of epoxy resin formulations. The epoxy resin formulations were prepared by varying the curing accelerator content. The curing behavior was investigated by viscosity measurements under isothermal conditions using a rheometer. The films were used in a general PCB manufacturing process and their adhesiveness to the electroplating layer was confirmed by peel strength tests. Their surface morphology after desmearing was examined by SEM. The peel strength of the epoxy films with a copper layer was directly dependent on their surface roughness.