A portable communication device comprising: a first printed circuit board, PCB, having a first connection terminal formed thereon; a first electronic component connected to the first connection terminal and disposed on the first PCB; a second PCB disposed over or under the first PCB having a second connection terminal formed thereon; a second electronic component connected to the second connection terminal and disposed on the second PCB; and an interposer disposed between the first PCB and the second PCB such that the first PCB, the second PCB and the interposer form an inner space together, the interposer including: a first surface facing the first PCB; a second surface facing the second PCB; and a plurality of vias disposed in the interposer and electrically connecting the first PCB and the second PCB to each other, the plurality of vias including a first via and a second via spaced apart from each other; a first end portion of the first via being electrically connected to the first connection terminal and a second end portion of the first via being electrically connected to the second connection terminal; and a ground region disposed on the second surface, the ground region including a first portion and a second portion, wherein the second end portion of the first via is surrounded by the first portion, and an end portion of the second via exposed at the second surface is surrounded by the second portion, and wherein a plating pad of the second via is disposed on the second surface and electrically connected with the second portion of the ground region via an interconnect. a first printed circuit board, PCB, having a first connection terminal formed thereon; a first electronic component connected to the first connection terminal and disposed on the first PCB; a second PCB disposed over or under the first PCB having a second connection terminal formed thereon; a second electronic component connected to the second connection terminal and disposed on the second PCB; and an interposer disposed between the first PCB and the second PCB such that the first PCB, the second PCB and the interposer form an inner space together, the interposer including: a first surface facing the first PCB; a second surface facing the second PCB; and a plurality of vias disposed in the interposer and electrically connecting the first PCB and the second PCB to each other, the plurality of vias including a first via and a second via spaced apart from each other; a first end portion of the first via being electrically connected to the first connection terminal and a second end portion of the first via being electrically connected to the second connection terminal; and a first surface facing the first PCB; a second surface facing the second PCB; and a plurality of vias disposed in the interposer and electrically connecting the first PCB and the second PCB to each other, the plurality of vias including a first via and a second via spaced apart from each other; a first end portion of the first via being electrically connected to the first connection terminal and a second end portion of the first via being electrically connected to the second connection terminal; and a ground region disposed on the second surface, the ground region including a first portion and a second portion, wherein the second end portion of the first via is surrounded by the first portion, and an end portion of the second via exposed at the second surface is surrounded by the second portion, and wherein a plating pad of the second via is disposed on the second surface and electrically connected with the second portion of the ground region via an interconnect.