Semiconductor package s and methods of forming the same are disclosed. The semiconductor package includes a chip, a redistribution circuit structure and a UBM pattern. The redistribution circuit structure is disposed over and electrically connected to the chip and includes a topmost conductive pattern. The UBM pattern is disposed over and electrically connected to the topmost conductive pattern, wherein the UBM pattern includes a set of vias and a pad on the set of vias, wherein the vias are arranged in an array and electrically connected to the pad and the topmost conductive pattern.