Fig. 1. Development history of Micro-LED

Fig. 2. （a）Process flow for Micro-LED array fabrication^［40］；（b）Single pixel integration structure diagram on silicon^［41］.

Fig. 3. Pixel bonding.（a）Wire bonding；（b）Inverted chip bonding^［40］.

Fig. 4. Schematic diagram of thermal pressure soldering/reflow soldering flip-chip.（a）Section drawing of gold flip bonding^［52］；（b）Cu-Sn gold-free inverted bonding microscope^［54］；（c）Section drawing of indium flip bonding^［55］.

Fig. 5. Schematic diagram of metal microtube preparation and bonding process.（a），（b），（c）Preparation of metal microtubules；（d）Metal microtubule bonding process^［58］.

Fig. 6. Equivalent circuit diagram of passive drive

Fig. 7. Fabrication process of passive matrix.（a）Formation of isolation trenches；（b）Pixel patterning and evaporation of p-type electrodes form ohmic contact；（c）N-electrode stripes definition；（d）Patterning of transparent polyimide；（e）P-electrode stripes definition^［60］.

Fig. 8. CMOS driver.（a）Flip chip bonding of Micro-LED arrays and active matrix CMOS backplane；（b）Schematic diagram of pixel drive circuit^［61］.

Fig. 9. CMOS drive RGB Micro-LED display^［37］

Fig. 10. Schematic diagram of active TFT driving Micro-LED array.（a）Micro-LED and TFT drive backplane integration^［63］；（b）Micro-LED array and LTPS TFT driver cross-sectional structure diagram^［63］；（c）Cross-sectional view of dual-gate a-IGZOTFT driver Micro-LED display^［67］；（d）LTPO TFT drive structure cross-sectional view and circuit schematic^［62］.

Fig. 11. （a）2T1C active matrix pixel circuit diagram^［72］；（b）2T1C drive circuit panel configuration diagram^［73］.

Fig. 12. 3T1C pixel driver unit^［74］

Fig. 13. （a）Schematic diagram of 4T2C active matrix drive circuit；（b）Timing diagram of two frames^［40］.