Micro LED is also widely used in consumer electronics and wearable products.

Micro LED is a new generation of display technology, which is brighter, more efficient and lower in power consumption than existing OLED technology. Its outstanding features will give it an advantage not only in giant screen display, but also in consumer electronics and wearable products.In May 2017, apple began to develop Micro LED display technology.In February 2018, samsung has launched Micro LED TV products in CES2018.

Micro LED is to transfer a large amount of Micro LED at the micron level to the substrate, which is similar to a miniature outdoor LED display. Each Micro LED is addressed and can be individually driven and lit, which is more power-saving and faster than OLED.Micro LED technology has broken through the limitations of OLED, with higher brightness and saturation.In addition, as OLED materials are organic light-emitting diodes, they cannot be naturally compared with inorganic materials such as Micro LED in terms of service life.Micro LED, such as automobile headlight and large screen projection, will be more competitive in application fields that require a higher life span of display products.

Compared with OLED, LCD and other technologies, Micro LED has certain advantages in various functional indicators (PPI, power consumption, brightness, thinness, color rendering index and flexibility panel adaptability).However, LCD panel has a long application time, a high supply chain maturity, and a price advantage. In the field of 30-80 inch TV product application, it still has a strong competitiveness.In addition, quantum dots, BD Cell and Mini backlight, as technical supplements, can also improve the display performance of LCD products to a certain extent.

Micro LED is superior to OLED in performance, but at present OLED is relatively mature in consumer electronics market under 30 inches, especially in mobile phone market.In addition to the advantages of folding display products, OLED is more mature in the integration of functions such as touch control, under screen fingerprint and under screen camera.However, Micro LED is short of supporting supply chain in relevant aspects, and the current product cost is also relatively high. Secondly, Micro LED still needs to be improved in terms of chip mass transfer, and its production efficiency is not yet superior to OLED. 

The Display principle of MicroLED Display is to film, miniaturize and array LED structure design, and its chip size is only about 1-10um.After that, Micro LED is transferred to the substrate in batch. The substrate can be rigid and soft transparent and opaque substrate.After finishing the protective layer and the upper electrode in the physical deposition process, the packaging of the upper substrate can be carried out, and the simple structure of Micro LED display can be completed.

To make a display, the chip surface must be an array structure like an LED display, and each pixel must be addressable and individually driven.If the CMOS is driven by complementary MOS, the active addressing drive architecture is adopted. Micro LED array chips and CMOS can be pasted by packaging technology. 

Once pasted, Micro LED can improve brightness and contrast by integrating microlens array.Micro LED array connects the positive and negative electrodes of each Micro LED through vertically interlaced positive and negative gate electrodes. Through the sequence of electrode wires, Micro LED is lit up by scanning to display images.

Since 2008, LED photoelectric conversion efficiency has been greatly improved, and more than 100lm/W has become a mass production standard.Therefore, the application of MicroLED display, because of its self-luminous display characteristics, coupled with the simple structure of almost matte consumables, can easily realize the display design of low energy consumption or high brightness.This can solve the two major problems of current display applications. First, more than 80% of the energy consumption of wearable devices, mobile phones, tablets and other devices is on the display. Low-energy display technology can provide longer battery life.The second is the problem that the strong ambient light causes the fading of the image on the display and the poor identification. The high brightness display technology can make its application more broad.And Micro LED display products can almost adapt to various display sizes.

Micro LED products have certain cost competitiveness in the field of Micro display.At present, microprojection technology mainly includes digital light processing, reflective silicon substrate liquid crystal display, and mems scanning, but these three technologies must use external light source, which makes the module volume not easy to be further reduced and the cost is also high.By contrast, Micro LED microdisplays with spontaneous lighting do not require external light source, and the optical system is relatively simple, so it has advantages in miniaturization of module volume and cost reduction.

MicroLED also has a wide range of commercial prospects.At present, if only considering the existing technical capabilities, Micro LED has two major application directions. One is the wearable market, represented by apple, which is reported to have studied the feasibility of using Micro LED display technology in watches, mobile phones and other products.Wearable devices with MicroLED display are expected to be launched in the future.Second, the super size TV market, represented by samsung and SONY, has shown Micro LED cledis at CES this year with excellent performance in resolution, brightness and contrast.

In the short term, Micro LED market focuses on ultra-small displays. In the medium and long term, Micro LED is widely used in various fields, including wearable devices, large indoor display screens, head-mounted displays (HUD), head-up displays (HUD), car taillights, wireless optical communications li-fi, AR/VR, projectors and so on.

Considering the technical difficulties such as batch transfer, it is difficult to replace OLED or LCD in mobile phone applications in a short time.After the end of Micro LED lei, the lit LED crystal film needs to be directly transferred to the drive back plate without packaging. This technology is called batch transfer, or massive transfer.

There are two technical difficulties: 1. The transfer is only the LED crystal epitaxial layer that has been lit, not the original substrate. The transfer thickness is only 3%.2. Tens of thousands or even hundreds of thousands of leds need to be moved in one transfer, which is huge. Moreover, the uniformity of grain placement after the transfer needs to be considered, and new technologies are required to meet this requirement.