A package structure and a formation method of a package structure are provided. The method includes forming a conductive structure over a carrier substrate and disposing a semiconductor die over the carrier substrate. The method also includes forming a protective layer to surround the conductive structure and the semiconductor die. The method further includes forming an insulating layer over the protective layer. The insulating layer has an opening exposing a portion of the conductive structure. In addition, the method includes forming a conductive layer over the insulating layer. The conductive layer fills the opening, and the conductive layer has a substantially planar top surface.