News briefing 

    Ever Since Micro LED manufactures have been able to gradually overcome the bottleneck of mass production, more products are now being commercialized for use in public billboards and TV sets which have, in turn, been launched and have reached the point of mass production. Macroblock of Taiwan has worked with PCB manufacturer, Unimicron, to launch Micro LED products based on PCB as its substrate. 

 

 

Impact analysis 

    The principle of Micro LED display technology is to move micron-scale RGB tri-color Micro LED chips to the substrate. In addition to its superior image quality (contrast, brightness, reaction speed, etc.), it also possesses the characteristics of self-illumination without a backlight source as well as having the advantages of low energy conservation, simplicity in structure and a small and thin size. It is fast becoming one of the key technologies in display manufacturing and is being deployed aggressively in various countries around the world. In the past, the main reason for the delayed commercialization of Micro LEDs lay at the technical bottleneck of mass transfer. If the size of the crystal charge of the LED is smaller than 5 μm, the transfer cost will be more than four times that of the die cost.

 

    As more manufacturers such as Luxvue (Apple), X-Celeprint, ITRI, eLux, and others invest in the development of massive transfer, certain progress has been made if they use low melting-point bonding materials or embossing heads for pressuring to achieve the objective of capturing LED. Hence, the advancement for commercial use will be lot faster. Public information displays, amongst other applications, is a currently popular market for the use of Micro LED, and amounts to approximately 20% to 30% of the public information display market.

 

    Micro LED’s terminal products can be quite varied depending on the field of application, whereas back-panel materials used in micro-assembly will also be different. For example, large-format displays such as large billboards and supra-sized displays used in theaters are expected to use PCBs as back-panel materials in the future. As for regular TVs and NB/PC monitors, they would resort to a glass substrate as their back panel. For AR/MR and other products, they would utilize Si substrate as a back-panel material. Among these, large displays or outdoor billboards based on a PCB substrate are regarded as the future application with the greatest output value for Micro LED. For instance, both Sony's Cledis large display and Samsung’s 146-inch Wall large billboard have made use of PCB as the back panel for Micro LED.

 

    At present, LED spacing of public displays is mostly around 1.5~2mm, and many mainland-owned manufacturers have already listed this portion of the market as their key priorities. Among them, CEEPCB has already developed corresponding PCBs for mass production. In the future, these manufacturers will be working on PCB products with a 0.75mm LED spacing, and will continue to develop corresponding PCBs with a smaller distance between the die and the frame, and focus on the flatness of the board edge as well as on the higher hole-to-depth ratio. Only a few Taiwanese manufacturers put some effort into the research and development of this subject.