Provided are a semiconductor package and a method for forming the same, and a PCB (printed circuit board). The semiconductor package comprises: a PCB including a slit at a substantially central portion thereof, the PCB including an upper surface and a lower surface; a semiconductor chip mounted on the upper surface of the PCB; an upper molding layer disposed on the upper surface and covering the semiconductor chip; and a lower molding layer filling the slit and covering a portion of the lower surface of the PCB, wherein the PCB comprises a connecting recess at a side surface thereof, and the upper molding layer and the lower molding layer are in contact with each other at the connecting recess.