Electronic device including flexible printed circuit board

A flexible printed circuit board (FPCB), the FPCB comprising:

• a central portion;
• a first flexible portion connected to the central portion and configured to be partially bent;
• a second flexible portion connected to the central portion to be opposite to the first flexible portion and configured to be partially bent;
• a first sealing portion connected to the first flexible portion to be opposite to the central portion;
• a second sealing portion connected to the second flexible portion to be opposite to the central portion;
• a first extension portion connected to the first sealing portion to be opposite to the first flexible portion and configured to be partially bent;
• and
• a second extension portion connected to the second sealing portion to be opposite to the second flexible portion and configured to be partially bent,
• wherein the FPCB is formed in a multi-layer structure in which a plurality of substrates having uneven surfaces according to metal patterns are stacked in a stacking direction,
• wherein a stepped space by the uneven surfaces is formed between the plurality of substrates, and
• wherein a ratio of an area of the stepped space to a length of the first sealing portion and the second sealing portion is less than or equal to a ratio of an area of the stepped space to a length of the first flexible portion and the second flexible portion.

An electronic device, the electronic device comprising:

• a display comprising a first area and a second area;
• a first housing comprising a first surface on which the first area is disposed, and a second surface opposite to the first surface;
• a second housing comprising a third surface on which the second area is disposed, and a fourth surface opposite to the third surface;
• a hinge structure connecting the first housing and the second housing to be foldable about a folding axis and configured to change the first area and the second area between a first state of forming substantially the same plane and a second state of facing each other;
• a first bracket connecting the first housing and the hinge structure and comprising a first opening penetrating through a surface thereof;
• a second bracket connecting the second housing and the hinge structure and comprising a second opening penetrating through a surface thereof;
• a first printed circuit board (PCB) disposed between the first bracket and the second surface;
• a second PCB disposed between the second bracket and the fourth surface;
• a flexible printed circuit board (FPCB) with at least a portion disposed between the hinge structure and the display, and both ends respectively connected to the first PCB and the second PCB by passing through the first opening and the second opening;
• a first sealing member surrounding a perimeter of a first sealing portion of the FPCB positioned inside the first opening, and sealing between the first opening and the first sealing portion;
• and
• a second sealing member surrounding a perimeter of a second sealing portion of the FPCB positioned inside the second opening, and sealing between the second opening and the second sealing portion,
• wherein the FPCB is formed in a multi-layer structure in which a plurality of substrates having uneven surfaces according to metal patterns are stacked in a stacking direction, and
• wherein a waterproof member for filling a stepped space formed by the uneven surfaces between the plurality of substrates is disposed in the first sealing portion and the second sealing portion.