Enhancement of light extraction efficiency of multi-chips light-emitting diode array packaging with various microstructure arrays

Low light extraction efficiency (LEE) is one of the most challenging points for light-emitting diode (LED) array packaging. Simulation and Experimental analysis of LEE enhancement of LED array packaging with microstructures on packaging silicone gel is presented. To obtain high LEE, microstructures including inversed spherical cap, cylinder-grooves, and V-grooves, are introduced on top surface of packaging silicone gel. Conventional chip (CC) and vertical thin film chip (VTFC) are adopted. Simulation results demonstrate that microstructures are able to effectively improve the LEE of LED array packaging. Experimental results show that inversed spherical cap, cylinder-grooves, and V-grooves structures which are manufactured by molding process can increase the LEE to 12.13%, 10.23%, and 7.44% respectively. This method would be a potential way in improving the LEE of LED array packaging with low profile and high luminous efficiency.