A substrate layered structure including a first circuit board; a second circuit board overlapping the first circuit board; and interposer blocks interposed between the first circuit board and the second circuit board and spaced apart from each other. Further, each corresponding interposer block includes a dielectric block body; a plurality of signal via holes passing through the dielectric block body and transferring signals between the first circuit board and the second circuit board; and a plurality of signal pads arranged at first ends of the signal via holes and connected to the first circuit board and arranged at second ends of the signal via holes and connected to the second circuit board.