Abstract: Method and device for molding integrated circuit packages using dambarless lead frames are disclosed. The mold dies and the lead frame have means for preventing resin leakage out of the mold dies during the package molding step. The leakage preventing means may comprise a tape put on the leads, an enlarged area sections provided on each lead and notches formed on each lead. The leakage preventing means may comprise projections formed on a lead pressing frame of one of the mold dies. In another embodiment, an auxiliary lead frame, which has a plurality of rectangular openings and will be fixed to a bottom mold die, is used as the resin leakage preventing means. When using the auxiliary lead frame, the dambarless lead frame is laid on the auxiliary lead frame and clamped by a top mold die. The enlarged area sections may be formed on the inner leads exclusively or on both the inner and outer leads.