360 PPI Flip-Chip Mounted Active Matrix Addressable Light Emitting Diode on Silicon (LEDoS) Micro-Displays

Journal of Display Technology (Impact Factor: 2.24). 04/2013; 9(99). DOI: 10.1109/JDT.2013.2256107


In this paper, we describe the design and fabrication of 360 PPI flip-chip mounted active matrix (AM) addressable light emitting diode on silicon (LEDoS) micro-displays. The LEDoS micro-displays are self-emitting devices which have higher light efficiency than liquid crystal based displays (LCDs) and longer lifetime than organic light emitting diodes (OLEDs) based displays . The LEDoS micro-displays were realized by integrating monolithic LED micro-arrays and silicon-based integrated circuit using a flip-chip bonding technique. The active matrix driving scheme was designed on the silicon to provide sufficient driving current and individual controllability of each LED pixel. Red, green, blue and Ultraviolet (UV) LEDoS micro-displays with a pixel size of 50 μm and pixel pitch of 70 μm were demonstrated. With a peripheral driving board, the LEDoS micro-display panels were programmed to show representative images and animations.

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    • "The red, green and blue LEDoS micro-displays have a resolution of 30 × 30 and a pixel pitch of 140μm, equivalent to 180 pixels per inch (PPI). The electrical characteristics and spectral luminosity profile of the three LEDoS chips were measured and discussed in reference [17]. In our red LEDoS chip, the driving transistors and LED pixels were in current sink connection because the p-and n-electrodes of red LED were reversed. "
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