A method for manufacturing a display device can include growing a plurality of light emitting (LEDs) on a growing substrate; forming a member having a thermal flow characteristic on at least one side surface of each of the plurality of LEDs; separating each of the plurality of LEDs from the growing substrate; forming a plurality of assembly grooves in a wiring substrate for defining pixel regions; assembling the plurality of LEDs at locations respectively corresponding to the plurality of assembly grooves; and applying heat to the wiring substrate to perform a reflow process for adjusting a position of at least one of the plurality of LEDs.