Effect of chip spacing on light extraction for light-emitting diode array

Opt Express. 2015 Jun 1;23(11):A640-9. doi: 10.1364/OE.23.00A640.

Abstract

GaN LED array in packaging is important for the demand of high optical flux. In order to tighten the whole packaging size, the spacing among LED chips becomes an important factor in the packaging design. This study is to investigate the change of the light extraction when a GaN LED chip array packaging is applied. The shielding effect with various spacing for the GaN LED array with or without silicon encapsulation is obtained. We apply the Monte Carlo ray-tracing method in the simulations to analyze the optical behavior of the two major types of the GaN LED array. The shielding effect is more dominant for bare chip packaging. When a silicone thin dispensing layer is applied, the shielding effect is not obvious because of more light extraction, the neighbor dies play an important role in photon recycling.