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

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 degrees mini-CSPLED, 150 degrees mini-CSPLED, and 180 degrees mini-CSPLED with different emission angle structures were fabricated using a CSP process. In terms of component characteristics, although the 180 degrees mini-CSPLED light output power is about loss 4% (at 10mA) compared with 150 degrees 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 150m. This result can achieve a brightness uniformity of 86% in a 180 degrees mini-CSPLED BLU + 150-m-thick QD films as compared to the 120 degrees mini-CSPLED BLU and 150 degrees mini-CSPLED BLU.