A package board includes a stack structure that includes a circuit layer and a fiber layer. The fiber layer includes at least one first fiber that extends in a first direction and is a non-woven fiber. Also, a prepreg includes a first fiber that is a non-woven fiber; a plurality of second fibers that are spaced apart from the first fiber and are woven fibers; and an insulating layer that fills gaps between the first fiber and the plurality of second fibers.