Abstract: An LED light source including a plurality of LED dies, a corresponding number of heat sinks each having an integral light reflector on which a die is mounted, and a dielectric substrate on one side of which the heat sinks are contiguously mounted in spaced apart relationship with the light reflector remote the dielectric substrate. The heat sinks each include an island of material having high thermal conductivity and of sufficient thickness to ensure that heat generated in the die is distributed substantially uniformly over a contact region between the substrate and the heat sink.