High-Uniformity Planar Mini-Chip-Scale Packaged LEDs with Quantum Dot Converter for White Light Source

• Published in: Nanoscale research letters Vol. 14; no. 1; pp. 182 - 10
• Main Authors: Chen, Lung-Chien, Tien, Ching-Ho, Chen, De-Fu, Ye, Zhi-Ting, Kuo, Hao-Chung
• Format: Journal Article
• Language: English
• Published: New York Springer US 29.05.2019; Springer Nature B.V; SpringerOpen
• Subjects: Backlight; Brightness; Chemistry and Materials Science; Chromaticity; Converters; Diffusion plating; Diodes; Emission analysis; Film thickness; GaN; Light emitting diodes; Light sources; Luminous intensity; Materials Science; Mini-CSPLED; Molecular Medicine; Nano Express; Nanochemistry; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering; Plates (structural members); Quantum dot; Quantum dots; Thick films; White light; Mini-CSPLED; Quantum dot; GaN; Backlight
• ISSN: 1931-7573; 1556-276X
• DOI: 10.1186/s11671-019-2993-z

This study proposes a novel direct-lit mini-chip-scale packaged light-emitting diode (mini-CSPLED) backlight unit (BLU) that used quantum dot (QD) film, diffusion plate, and two prism films to improve brightness uniformity. Three different luminous intensity units, 120° mini-CSPLED, 150° mini-CSPLED, and 180° mini-CSPLED with different emission angle structures were fabricated using a CSP process. In terms of component characteristics, although the 180° mini-CSPLED light output power is about loss 4% (at 10 mA) compared with 150° mini-CSPLED, it has a large emission angle that forms a planar light source that contributes to improving the BLU brightness uniformity and reduced quantity of LEDs at the same area. In terms of BLU analysis, the blue mini-CSPLEDs with different emission angles excite the different QD film thicknesses; the chromaticity coordinates conversion to the white light region. The BLU brightness increases as the QD film thickness increases from 60, 90, and 150 μm. This result can achieve a brightness uniformity of 86% in a 180° mini-CSPLED BLU + 150-μm-thick QD films as compared to the 120° mini-CSPLED BLU and 150° mini-CSPLED BLU.