A surface mounting structure applied to a BGA includes a substrate, a first soldering pad, a first lead, a second lead and a passivation layer. The substrate has a top surface for the first soldering pad to be disposed thereon. The first lead has a first end connected to the first soldering pad and a second end. The second lead has a third end connected to the first soldering pad and a fourth end connected to the second end of the first lead. A well is defined among the first lead, the second lead, and the first soldering pad. The passivation layer covers the top surface of the substrate, and has a first opening corresponding to the top of the first soldering pad to expose the first soldering pad and the well. Chip failure resulting from the warp occurring at four corners in the surface mounting procedure is prevented.