How innovative LED package technology enables new solid-state lighting designs

The popular high-power LEDs in use today are all formed of three basic elements: a ceramic substrate, generally made of aluminium oxide (also known as alumina) or of aluminium nitride; the LED chip consisting of a die and a phosphor coating affixed on top of the substrate; and an over-moulded silicone lens which encapsulates the LED chip. An example, the 219C high-power LED from Nichia, is shown in figure 1. Small variations in the design of high-power LEDs can be found between one manufacturer and another, and even between different product families made by a single manufacturer.