A display panel manufacturing method includes: putting a first substrate into a liquid; putting a plurality of light emitting diodes into the liquid in which the first substrate is put; performing fluidic self-assembly to attach the plurality of light emitting diodes to the first substrate; transferring the plurality of light emitting diodes attached to the first substrate to a second substrate; and thermally compressing the plurality of light emitting diodes transferred to the second substrate onto the second substrate.