Display device and manufacturing method thereof

A display device comprising:

• a substrate having opposite first and second surfaces, and comprising a display area, and a peripheral area around the display area in plan view;
• transistors above the first surface of the substrate;
• data lines above the first surface of the substrate, and electrically connected to the transistors;
• light-emitting diodes above the first surface of the substrate;
• a front data pad above the first surface of the substrate, electrically connected to the data lines, and arranged in a first direction along a first side of the substrate;
• a first insulating layer on the front data pad;
• a rear data pad under the second surface of the substrate, and arranged in the first direction;
• a second insulating layer under the rear data pads, and defining a first opening and a second opening overlapping the rear data pads;
• and
• a side wire electrically connecting the front data pad and the rear data pad, electrically connected to and overlapping the rear data pad through the first opening, and comprising a residue at a same layer as, and comprising a same material as, the side wire.

A tiled display device, comprising:

• display devices;
• an adhesive layer between adjacent ones of the display devices;
• and
• a driving circuit unit on a rear surface of at least one of the display devices,
• wherein the display devices comprise:
• a substrate having opposite first and second surfaces, and comprising a display area, and a peripheral area around the display area in plan view;
• and
• transistors above the first surface of the substrate;
• data lines above the first surface of the substrate, and electrically connected to the transistors;
• light-emitting diodes above the first surface of the substrate;
• front data pads above the first surface of the substrate, electrically connected to the data lines, and arranged in a first direction along a first side of the substrate;
• a first insulating layer above the front data pads;
• rear data pads under the second surface of the substrate, and arranged in the first direction;
• a second insulating layer under the rear data pads, and defining a first opening and a second opening overlapping one of the rear data pads, a virtual line extending in the first direction from the first opening not overlapping the second opening;
• and
• a first side wire electrically connecting a first front data pad of the front data pads to a first rear data pad of the rear data pads, and electrically connected to and overlapping the first rear data pad through the first opening.