1. A thin-film fingerprint sensor package comprising: a fingerprint sensor chip having an active surface including a sensing area; a plurality of bumps disposed on the active surface; a wiring film having an opening exposing the sensing area and a plurality of leads, wherein the leads have a plurality of inner ends bonded to the bumps; an encapsulant encapsulating the bumps; and a metal base mechanically holding the fingerprint sensor chip; wherein the wiring film further has at least a ground lead electrically connecting the fingerprint sensor chip to the metal base.