Does COG technology permanently change the LED display industry chain?
For the LED display industry, the hottest concept in recent years is mini-led or micro-LED.
However, since 2021, more and more people in the industry have realized that the "synonym" that will truly completely change the pattern of the LED display industry may not be mini-led or micro-LED, but COG technology and the TFT glass substrate behind COG technology. .
What is COG technology
The application of COG technology in LED display can be simply summarized as: LED display unit packaging technology in which LED light-emitting crystals are directly packaged on a TFT glass substrate (or a TFT resin substrate). There are three main features of this technology: 1. LED crystal particles are directly packaged, which is a massive operation at the sub-wafer level, 2. The backplane circuit uses new products such as TFT glass substrates to replace traditional PCB circuit boards, 3. LED The working mode of the crystal particles is AM actively driven, rather than the traditional PM passive driving.
Judging from the development history of LED display products, it has experienced in-line technology, SMD surface mount technology and COB technology. Among them, the difference between COB and traditional SMD surface-mount packaging is that COB technology directly integrates the light-emitting chip LED crystal particles into the PCB board. That is, it also directly manipulates LED crystal particles and is a batch operation. Compared with COG technology, the further difference is that 1. COG uses a glass substrate and AM driver instead of a traditional PCB substrate; 2. LED crystal particles operated by COG technology at the same time tend to be higher in scale and smaller in size.
The core reason for the development of COG technology is that the smoothness of the glass substrate is more suitable for the simultaneous operation of a large number of LED crystal particles of the mass transfer technology. It greatly improves the upper limit of the mass transfer technology and reduces the difficulty and process error factors of the mass transfer.
In fact, from the in-line technology, SMD surface-mount technology, COB technology, to COG technology, the core difference on the product side is that the pixel pitch of LED display is getting smaller and smaller, and the LED crystal particles per unit display area The scale of integration is getting higher and higher." ——This is also the main way forward for small-pitch LED display, fine-pitch LED display, and mini-led to micro-LED technology.
Therefore, many companies in the industry believe that if mini-led or micro-LED display technology is further upgraded to higher pixel density products, COG technology, or massive transfer technology on glass substrates, will be a necessary "basic technology" . However, COG's internal changes and revolutions in the LED display industry are far less significant than their "revolutions" in the external supply chain of the LED display industry.
Changes from PCB to TFT glass substrate
An LED display company wants to develop LED display products based on COG technology. The core technology and component support mainly include: 1. mini-led or micro-LED level LED crystal particles, 2. suitable for COG driver IC, 3. It owns massive transfer process technology, 4. Suitable TFT glass substrate batch supply chain.
Among them, the core technology of LED display terminal companies is mainly concentrated in mass transfer and terminal module packaging; the other three aspects require "external procurement". However, the upstream market for LED crystal particles and driver ICs is completely different from TFT glass substrates, and TFT glass substrates are also completely different from traditional LED displays using PCB substrates.
That is, the PCB substrate of traditional LED display, the LED crystal particles and driver IC used in COG are not a "monopoly" market. The supply of TFT glass substrates is in a "relative monopoly" state. In particular, the production capacity of large-size TFT glass substrates above the 8th generation line has the three characteristics of capital-intensive, technology-intensive, and production-intensive. The number of global core suppliers is not only scarce, but each is a giant company.
In other words, the current large-scale enterprises involved in the processing of TFT large-size glass substrates are each giant with an investment scale of 100 billion yuan: such as Samsung, LG, Innolux, AUO, BOE, Huaxing Optoelectronics, Huike, Shenzhen Tianma... …
Therefore, in the COG era, TFT glass substrates, as the upstream industry chain, have the industry control and pricing power of related LED display products, which have an unprecedented "decisive" status in the history of LED display. For example, at the TCL Huaxing Ecological Conference in November, the COG technology mini-led and micro-LED display products it showed at least involved the LED display industry, including Sanan Optoelectronics, Leyard, Jufei Optoelectronics, etc. "Upstream and downstream partners", covering a huge product line from 1.X-inch miniature displays to 125-inch giant displays.
Compared with the traditional LED wafers and crystal particles, high-precision PCB boards, IC, LED particle packaging and terminal enterprises in the LED display industry, the "quantity" and the wide supply of the TFT glass substrates may have fewer "suppliers" for COG technology. Many, stronger monopoly, larger volume: often a TFT glass substrate giant will correspond to multiple LED wafer and crystal particle manufacturers, as well as multiple LED downstream terminal enterprises. This pattern is likely to make COG products, TFT glass substrate companies become the intermediate connection point of the "dumbbell" structure of the entire industry chain.
Whether COG allows LED displays to change from the traditional grid-based supply chain competition to the dumbbell-shaped supply chain competition in the future, this is the most concerned issue in the industry! "Industry sources said that the emergence of the latter, or will become a fundamental change in the law of competition in the LED display industry.
TFT glass substrate companies show new leading position in LED display
At the TCL Huaxing DTC 2021 Global Display Ecological Conference held on November 16, Huaxing Optoelectronics displayed glass substrate-based LED display products including: 125-inch transparent MiniLED direct display, 75-inch P0.6 oxide AM direct display Mini LED TV, A 1.37" AM Micro LED watch screen integrated with In-cell touch technology; a 7.1-inch flexible Micro LED screen; and a 6.24-inch high-brightness Micro LED screen and many other differentiated products.
Coincidentally, Shenzhen Tianma, BOE and other companies have also repeatedly displayed various mini-led and micro-LED display products and LED splicing display products based on glass substrates since 2020. Samsung and Innolux have also demonstrated mini-led and micro-LED glass substrate direct display products based on new colorization technologies such as color conversion film.
Glass substrate + mass transfer + mini LED and micro LED Yanran constitute a new innovative display direction that is equivalent to OLED technology in the eyes of display panel giants, and even surpasses the potential of OLED. Among these innovations, LED display products for color TVs and splicing large screens have completely overlapped with the "main technology and market attack" direction of traditional small-pitch LED companies, and have become the leader in LED display cutting-edge technology innovation in recent years.
From the industry's perspective, in the small and medium-sized display market, no other company has the ability to compete with traditional panel giants on the COG technology's micro LED direct display innovation. However, in the large-size, color TV and engineering large-screen markets, the COG LED display era, the battle for the "market position" between panel companies and traditional small-pitch LED display companies and LED packaging companies has begun. Deepening the upstream cooperation with TFT glass substrate suppliers and panel companies is the key for small-pitch LED companies to continue to be the market C-level in the future COG era:
From the perspective of traditional LCD and OLED display industries, panel companies have mastered both TFT glass substrate products and the structured process flow of functional materials (such as liquid crystal or OLED) on the substrate-downstream terminal companies have very little core workload on the display side , More is the integration of the whole machine. However, in the traditional small-pitch LED display industry, especially COB technology products, small-pitch LED terminal companies have mastered the initiative in most industrial links, including the massive transfer process of LED crystal operations, in addition to LED wafers. . ——The latter is equivalent to the "structured process flow on the substrate of functional materials (such as liquid crystal or OLED)" in the traditional panel industry.
That is, panel companies and small-pitch LED companies, who master the core process of massive transfer, will have an absolute "fixed touch" effect for the future COG era, LED display industry, and the value status of different companies. In other words, if panel companies insist on getting involved in massive transfers and packaging, it may lead to the reduction of the "technical content" and "industry voice" of LED display terminal companies to a very low level in COG products.
This possibility represents the "proactiveness of panel companies" in the COG era and the "passiveness" of small-pitch LED companies. This is also the biggest "worry" of the LED display industry for COG technology in addition to "cost power" and "market demand".
To sum up, the impact of COG technology on the LED display industry is far greater than any previous "process technology progress", not only surface mount and COB cannot be compared with them, but also massive transfer technology, mini led and micro LED, All are just part of the COG framework. COG technology in the LED display industry, the introduction of TFT glass substrate giants, leading to the development of the LED display industry pattern to "display panel" may actually exist. These changes require companies in the LED display industry not only to attach great importance to technology and product innovation, but also to establish their own collaborative system early in the industry chain ecology.
