Disclosed herein are various chip packaging structures and methods of fabrication. In one embodiment, a flip chip package structure can include: (i) a pad on a chip; (ii) an isolation layer on the chip and the pad, where the isolation layer includes a through hole that exposes a portion of an upper surface of the pad; (iii) a metal layer on the pad, where the metal layer fully covers the exposed upper surface portion of the pad; and (iv) a bump on the metal layer, where side edges of the bump do not make contact with the isolation layer.