Light-emitting diode and application therefor

A light emitting diode apparatus includes a substrate, a first conductive type semiconductor layer, a second conductive type semiconductor layer, a mesa, a lower insulating layer, a first pad and a second pad. The substrate has a first surface and a second surface opposite to the first surface. The first conductivity type semiconductor layer is disposed on the first surface of the substrate. The mesa is disposed on the first conductive semiconductor layer and has an active layer and the second conductive semiconductor layer. A peripheral edge of the first conductive semiconductor layer is exposed. The lower insulating layer covers the mesa and the first conductive semiconductor layer and has a plurality of first openings exposing the first conductive semiconductor layer along a peripheral edge of the substrate.