In a light-emitting diode package made in accordance with the present invention, a light-emitting diode assembly is positioned above a spacer assembly. In the light-emitting diode assembly, a die containing a light-emitting diode is positioned above a substrate. During operation, both the combination of at least one conductive plate adjacent to the die and a plurality of castellated side holes positioned on sides of the substrate, and a substrate thermal via positioned beneath the die, conduct thermal energy from the die to a light-emitting diode assembly pad on which the substrate is mounted. The light-emitting diode assembly pad conducts thermal energy to a top pad of the spacer assembly. A plurality of castellated side holes formed in sides of a spacer of the spacer assembly and a plurality of thermal vias positioned within the spacer conduct thermal energy from the top pad of the spacer assembly to a base pad of the spacer assembly.