Since the Micro LED has not been used by Apple on the new generation of iWatch, all aspects of its technology and applications have become more rational, and related manufacturers are also actively cooperating with the application.
At the same time, the Mini LED has gradually entered the reality. From top to bottom, manufacturers have followed suit. After last year’s trial, the major terminal application plants have basically completed the prototype design. From the exhibitions in recent years: Samsung, Lumens and other manufacturers have introduced Mini LED applications.
The market expects 18 years to be the beginning of the large-scale application of Mini LED.
Compared to current conventional applications, Mini LED does have its unique advantages:
For backlight applications, the Mini LED is generally a direct-down design that uses a large number of dense patches to achieve a smaller area of ??dimming. Compared to a traditional backlight design, the Mini LED can be implemented in a smaller light mixing distance. Good brightness uniformity, higher color contrast, and thus achieve ultra-thin, high color rendering, power saving of the end product.
At the same time, because of its design can be used with flexible substrates, with the curved surface of the LCD can also achieve a similar OLED surface display under the condition of ensuring quality, on the other hand, because the current OLED is self-luminous organic materials, in terms of reliability Mini LED It is also very advantageous; based on the mature LED industry chain, the cost of using Mini LED backlight is only about 60% of the same size OLED, which is very competitive in all aspects.
For display applications, the RGB Mini LED overcomes the defect of wire bonding and reliability of the positive-fit chip, and at the same time, it combines the advantages of the COB package to make it possible to further reduce the dot pitch of the display screen. The visual effect of the corresponding terminal product is greatly enhanced, and the viewing distance is also improved. Can be greatly reduced, so that indoor display can further replace the existing LCD market.
On the other hand, the use of RGB Mini LED with a flexible substrate can also achieve a high-quality display of the curved surface. With its self-luminous characteristics, it has a very broad market for some special modeling needs (such as automotive display).
As can be seen from the above, the Mini LED has a great advantage over other competitors in the current situation faced by the LED. Based on this, the various manufacturers are also researching, from the current situation, although the size of the chip and the chip is installed. The small pitch chips are similar but there are many differences.
Its technology has the following characteristics and difficulties:
Judging from the process route, the current Mini LED adopts the flip chip structure, mainly because the flip chip does not need to be wired, which is suitable for the needs of the ultra-small space, and it is also suitable for a variety of materials of the package substrate, and it is precisely because of this, The reliability is also obviously improved, and the maintenance cost of the use of the terminal products is reduced. Therefore, during the actual production process, the control of the flip-chip process is extremely important. At the same time, in the case of a small size, the flatness of the welding surface, the design of the electrode structure, and the ease of welding. The adaptability of the welding parameters and the latitude of the package are the difficulties and focuses of its design.
For the backlight application of Mini LED, due to the ultra-thin terminal requirements, combined with the cost and control difficulties, the chip can be achieved in a wider range of LED chip spacing to achieve a smaller light mixing distance, and then reduce the thickness of the whole machine, so how Implementing the light emission control of the chip and the consistency in the later use process are the key points.
For display applications using RGB Mini LEDs, the brightness concentration required for conventional small-pitch chips, the brightness consistency at low currents, and the low and consistent capacitance characteristics are eliminated. The use environment and post-maintenance require higher requirements for reliability. It is the red light chip that needs to carry out the substrate transfer during the process of manufacturing flip-chips. The overall process is more complicated, and the transfer technology, production yield control, and reliability during use are the key considerations.
Due to the small size of the Mini LED chip and the requirement for consistency of light color, the Mini LED is currently used in an all-in-ones mode. The operating efficiency is low. If the number of products is expected to increase with the market, the application needs to be in a single product. When working on a chip with more than one hundred kilowatts, the efficiency limit is more obvious. Therefore, how to cooperate with the application side and effectively improve the operating efficiency is also the current focus.