An embodiment provides a semiconductor package including: a first redistribution layer structure including a plurality of redistribution vias and a plurality of UBM structures; and a first semiconductor die on the first redistribution layer structure, wherein each of the plurality of UBM structures includes a UBM via; and a UBM wire line extending in a horizontal direction on the UBM via and electrically connecting one of the plurality of redistribution vias and the UBM via in the horizontal direction.