With the progressive development of display technology, the micro-LED (Light Emitting Diode) display technology has gained more and more attention due to the advantages thereof. Micro-LED is derived from LED, but it is the same with OLED (Organic Light Emitting Diode), it also has a self-luminous advantage, while the performances thereof are more improved than those of the OLED. Micro-LED has many advantages, such as power saving, high brightness, long life, low power consumption, high luminous efficiency, fast response, small size and so on. At present, many enterprises have been studying the micro-LED technology.