The present invention is applicable to a display device-related technical field and relates to, for example, a substrate assembly of a display device using a micro light-emitting diode (LED) and to a method for manufacturing same. The present invention relates to a method for assembling individual light-emitting diodes on a plurality of individual device regions of a first substrate assembly in which the plurality of individual device regions are partitioned on a first substrate and first electrodes are positioned in the individual device regions, wherein the method may comprise the steps of: positioning a second substrate assembly including an insulation layer positioned on the first substrate assembly, second electrodes positioned on the insulation layer, and a second substrate positioned on the second electrodes; injecting a fluid in which a plurality of light-emitting diodes are dispersed between the first substrate assembly and the second substrate assembly; and flowing the plurality of light-emitting diodes; and assembling at least one of the plurality of light-emitting diodes on the first electrodes positioned in the individual device regions.