A method comprising: preparing an interposer connectable to a two-dimensional, 2D, acoustic module and to an integrated circuit chip (140, 141, 142, 143, 144), the interposer including an insulator and a plurality of conductive lines each having a first end exposed to a first surface of the interposer and a second end exposed to a second surface of the interposer that is opposite to the first surface, wherein preparing the interposer includes stacking a plurality of circuit boards next to one another, upper surfaces of the circuit boards being coplanarly stacked to form the first surface of the interposer, lower surfaces of the circuit boards being coplanarly stacked to form the second surface of the interposer and placing at an outer side of the stack structure of the circuit boards an outer substrate, wherein an upper surface of the outer substrate is coplanarly stacked to join the first surface of the interposer and a lower surface of the outer substrate is coplanarly stacked to join the second surface of the interposer and providing second conductive lines in the outer substrate, first ends of the second conductive lines being exposed through the outer surface of the outer substrate and second ends of the second conductive lines being exposed through the second surface of the interposer; placing a bonding mask on the second surface of the interposer, the bonding mask comprising a transparent film; forming through-holes (132, 133, 134) on the bonding mask at positions corresponding to the conductive lines; filling the through-holes (132, 133, 134) with a conductive material for electrically connecting the integrated circuit chip (140, 141, 142, 143, 144) to the conductive lines; placing bump balls smaller than the through-holes (132, 133, 134) on electrode terminals of the integrated circuit chip (140, 141, 142, 143, 144); inserting the bump balls into the through-holes (132, 133, 134) while the integrated circuit chip (140, 141, 142, 143, 144) is aligned with the bonding mask; and bonding the integrated circuit chip (140, 141, 142, 143, 144) to the bonding mask by curing the conductive material, wherein the conductive material comprises conductive epoxy. preparing an interposer connectable to a two-dimensional, 2D, acoustic module and to an integrated circuit chip (140, 141, 142, 143, 144), the interposer including an insulator and a plurality of conductive lines each having a first end exposed to a first surface of the interposer and a second end exposed to a second surface of the interposer that is opposite to the first surface, wherein preparing the interposer includes stacking a plurality of circuit boards next to one another, upper surfaces of the circuit boards being coplanarly stacked to form the first surface of the interposer, lower surfaces of the circuit boards being coplanarly stacked to form the second surface of the interposer and placing at an outer side of the stack structure of the circuit boards an outer substrate, wherein an upper surface of the outer substrate is coplanarly stacked to join the first surface of the interposer and a lower surface of the outer substrate is coplanarly stacked to join the second surface of the interposer and providing second conductive lines in the outer substrate, first ends of the second conductive lines being exposed through the outer surface of the outer substrate and second ends of the second conductive lines being exposed through the second surface of the interposer; placing a bonding mask on the second surface of the interposer, the bonding mask comprising a transparent film; forming through-holes (132, 133, 134) on the bonding mask at positions corresponding to the conductive lines; filling the through-holes (132, 133, 134) with a conductive material for electrically connecting the integrated circuit chip (140, 141, 142, 143, 144) to the conductive lines; placing bump balls smaller than the through-holes (132, 133, 134) on electrode terminals of the integrated circuit chip (140, 141, 142, 143, 144); inserting the bump balls into the through-holes (132, 133, 134) while the integrated circuit chip (140, 141, 142, 143, 144) is aligned with the bonding mask; and bonding the integrated circuit chip (140, 141, 142, 143, 144) to the bonding mask by curing the conductive material, wherein the conductive material comprises conductive epoxy.