Thermal and optical performance characterization of bare and phosphor converted LEDs through package level immersion cooling

Abstract

Increased demand for high flux electronics requires creative and affordable thermal management approaches to meet the performance and lifetime expectations. In the present study, optical and thermal improvements of a new package level liquid coolant encapsulation that directly targets heat generation zones are studied for bare and phosphor converted LEDs. As heat both at chip and phosphor composite regions are being generated, a series of detailed experimental and theoretical characterization is performed in order to examine the capability of the new cooling method. The findings can be used to extend the application of precisely controlled liquid packing on the heat source region of optoelectronic components. This method has shown a 15% reduction in thermal resistance and a 7% increase in power conversion efficiency of LED packages. The capacity of this method is mainly limited to the thermal conductivity of the coolant while a significant ability for improvement can be expected by utilizing thermally conductive particles such as hexagonal boron nitride inside the coolant.