RGB-Stack Light Emitting Diode Modules with Transparent Glass Circuit Board and Oil Encapsulation

Abstract

The light emitting diode (LED) is widely used in modern solid-state lighting applications, and its output efficiency is closely related to the submounts’ material properties. Most submounts used today, such as low-power printed circuit boards (PCBs) or high-power metal core printed circuit boards (MCPCBs), are not transparent and seriously decrease the output light extraction. To meet the requirements of high light output and better color mixing, a three-dimensional (3-D) stacked flip-chip (FC) LED module is proposed and demonstrated. To realize light penetration and mixing, the mentioned 3-D vertically stacking RGB LEDs use transparent glass as FC package submounts called glass circuit boards (GCB). Light emitted from each GCB stacked LEDs passes through each other and thus exhibits good output efficiency and homogeneous light-mixing characteristics. In this work, the parasitic problem of heat accumulation, which caused by the poor thermal conductivity of GCB and leads to a serious decrease in output efficiency, is solved by a proposed transparent cooling oil encapsulation (OCP) method.

Electroluminescent Guest@MOF Nanoparticles for Thin Film Optoelectronics and Solid‐State Lighting

“…For the aforementioned reasons, white LEDs (WLEDs) have become one of the most commonly employed sources of light for illumination purposes. There exist two different approaches to fabricate WLEDs: i) RGB systems: [ 2 ] where the primary red, green and blue color emitters are combined in a controlled proportion to emit white light, and ii) Down‐converter WLEDs: where typically a GaN or InGaN blue LED chip is coated with a yellow phosphor like Ce 3+ :YAG or its derivatives, in which the combination of blue and yellow emitters produces white light. [ 3,4 ] Although these WLEDs have already presented important benefits over the traditional lighting sources, there are still challenges because of their limited efficiency (RGB devices), and/or unsatisfactory color rendering index (down‐converter WLEDs), or most notably these devices require the use of expensive and toxic rare‐earth elements.…”

Development of an Efficient Optical Model for Leds-Based White Light Spectrum Design Applications

“…In this study, three RGB LEDs, each provided with two reflective mirrors, are used to design an all-reflective color temperature-adjustable LED flashlight. The LED flashlight features an adjustable color temperature ranging from 2000 K to 6500 K, a uniformity of illuminance of 0.68, an average difference of uniformity of approximately 25%, and a color uniformity of 0.0042 (Hung et al 2013). Li et.…”