Transformer and power supply unit including the same

A transformer according to an embodiment of the present disclosure is mounted on the coil assembly, and a main board including the first, the second coil portion are stacked in the magnetic core and said magnetic core is disposed, is disposed between the coil assembly and the main plate It includes a base which, included in the laminate substrate is a layer are laminated is formed on which the first coil portion conductive pattern formed on the base may be provided with a plurality of terminal pins for connecting the laminated board and the main board to electrically is.