Product
With the participation of many first-line brands and wider application market coverage, a consensus is forming: Mini LED is an inevitable trend in the development of LCD technology.
Although the penetration of Mini LED backlight technology has accelerated, its development still faces multiple challenges such as cost and packaging technology routes. In particular, the competition between POB and COB solutions has always been the focus of Mini LED backlight technology.
So, as the competition in the commercialization process becomes increasingly fierce, which of the POB and COB solutions can better meet market demand and release its potential?
Industry experts discuss: the competition between POB and COB solutions
At the "2022 Experts Say Mini LED Backlight Mass Production and Application Trends Conference", companies such as Nationstar Optoelectronics, Dongshan Precision, Jingtai Co., Ltd., Jinko Electronics, Ruifeng Optoelectronics, and Yimei Xinchuang shared their latest insights on the selection and changes of packaging solutions such as POB and COB.
Nationstar Optoelectronics pointed out that the Mini POB process is less difficult and has strong mass production, but is restricted by the package size. It is currently mainly used in large-size modules, mainly targeting the mid- and low-end TV, display and automotive markets.
Mini COB can achieve ultra-thin design, and the outer diameter can reach 0mm and above; but the current process difficulty, equipment investment and material requirements are relatively high, and the module yield is low. However, with the continuous maturity of technologies in various links of the industrial chain, the yield problem will be improved, and its development prospects will far exceed Mini POB, realizing full-field applications.
From the current technical situation, it is expected that by 2025, Mini POB will still occupy a mainstream position, and it is more suitable for 43-85-inch TVs, 17-39-inch monitors and car displays, etc., with the highest overall cost performance; while Mini COB is more suitable for 13-16-inch laptops and 8-12.9-inch tablets. Single-board products help to improve yield and reduce costs. With the further maturity of technologies in various links of the industrial chain, it is expected that the mainstream market will be subverted after 2025.
Taking the choices of Apple and Samsung as examples, Jingtai shares believe that the reason why these first-line brands favor COB solutions is because of product demand. The COB solution can achieve 0 outer diameter and extreme thinness, meeting the needs of products such as tablets and laptops.
However, in small and medium-sized applications such as tablets and laptops, Mini LED not only faces its own cost pressure, but also faces the competitive threat of OLED, such as the competitive pressure brought by the mature industrial chain of small and medium-sized OLED and the consumer perception shaped by OLED's marketing for many years.
In contrast, large-size applications such as TVs and monitors are the main battlefield of Mini LED backlight technology. The development of the large-size market pays more attention to cost optimization, and the POB solution is undoubtedly the mainstream solution of Mini LED with its advantages of simple process, low material cost, good optical effect, low application requirements, high maturity of mass production solutions, and many possibilities for future partitioning.
Jinko Electronics is also optimistic about the application of Mini LED in the field of TV. They believe that "Mini LED+8K" will become the main product of TVs above 75 inches; and in TVs above 65 inches, "Mini LED+8K" will become the best combination to achieve high sales prices in high-end TVs, but its competitiveness is still dominated by cost.
In particular, the COB solution belongs to the chip level. In the development and process of key materials such as chips, substrates, solder paste, and silicone, the yield rate of COB light board production and the impact of one-time pass rate, rework efficiency, and yield rate on cost are particularly critical. However, the maturity of these processes requires the joint efforts of the entire supply chain.
Consistent with Jinko Electronics' views, Dongshan Precision also believes that the challenges and technological innovation opportunities facing Mini LED products lie in the pursuit of higher process yields to meet the cost of large market demand. Taking TVs and monitors as examples, the costs are mainly concentrated in packaging, PCB, driving and other links. The driving cost of Mini LED is determined by the number of partitions.
From a technical point of view, the Mini COB packaging route has added auxiliary means such as SPI (detecting solder paste), AOI (detecting appearance), lighting test (testing performance), and aging, which can effectively guarantee the pass rate.
Regarding the views on the packaging route, Ruifeng Optoelectronics and Yimei Xinchuang said that there is no absolute difference between POB and COB for a period of time.