Abstract: A system for separating an LED element using a hydrophobically modified LED element, includes: a first accommodating part for accommodating a substrate on which a plurality of LED elements are formed and an organic solvent; a second accommodating part disposed outside the first accommodating part and accommodating the first accommodating part and a fluid; a plurality of ultrasonic wave generating parts disposed under the second accommodating part and applying ultrasonic waves to the substrate; and a passage part which is connected to the second accommodating part and through which the fluid circulates, wherein the plurality of LED elements include a modifying compound on the surface thereof. The modifying compound includes a hydrophilic functional group located on the surface of the LED element and a hydrophobic functional group located on the opposite side of the hydrophilic functional group.

Abstract: A method for manufacturing a rod-type light emitting device, includes: sequentially forming a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer on a substrate; forming a mask pattern on the second conductive semiconductor layer; forming a plurality of rods by etching down to the first conductive semiconductor layer using the mask pattern by a dry etching method; forming an insulating layer on side surfaces of the plurality of rods so as to cover at least the entire longitudinal direction of the active layer; and separating each of the plurality of rods from the substrate.

Abstract: A light emitting diode (LED) display device includes: a first electrode layer and a second electrode layer disposed to be spaced apart from each other on a substrate; a plurality of micro-LED elements stacked in a longitudinal direction to be parallel to a plane of the substrate on the first electrode layer and the second electrode layer and stacked to be spaced apart from each other; and a first connection electrode coupled to both ends of the plurality of micro-LED elements and extending from one ends of the plurality of micro-LED elements to the first electrode layer and a second connection electrode extending from the other ends of the plurality of micro-LED elements to the second electrode layer and connected to the second electrode layer.