2026-08-04 17:28
Today, for every ten LCD panels produced in the world, about eight come from Chinese Mainland.
China's display industry went from "chip shortage and screen shortage" to becoming the world's number one in less than 20 years. During this process, a foreign-funded enterprise was never absent.
Corning Incorporated (NYSE: GLW) entered China in 1980 and was the first multinational company to invest in display glass substrate business in China.
For over 20 years, Corning's display glass factory has expanded along with Chinese panel companies, bringing its core manufacturing processes to China from the 5th generation line to the 8.5th generation line and then to the 10.5th generation line factory. This process is called 'fusion draw', which is a display glass substrate process developed by Corning in 1964 and is also one of the fundamental technologies that the global display industry still relies on today.
In the first half of this year, the International Trade Commission (ITC), an independent administrative body that has long resolved intellectual property disputes related to the US industry for global companies, including Chinese companies, made preliminary rulings on two intellectual property disputes between Corning and Rainbow Inc., both of which found infringement to be established, involving trade secrets and glass formula patents related to the melt down process.Previously, Corning had filed a civil lawsuit for trade secrets against Rainbow in China at the end of 2024.
Brendan Mosher, International Vice President and General Manager of Corning Display Technology Division, recently gave a media interview on this matter.
A technology developed in 1964
Glass substrate is the fundamental material at the bottom layer of display panels.
The screen of a LCD TV, a smartphone, or a tablet, when disassembled, the bottom layer of transparent film is the glass substrate. Panel manufacturers deposit thin film transistors, coat liquid crystals, package color filters on this layer of glass, and finally form a screen that can display images.
The process requirements for producing glass substrates are extremely demanding. A qualified high generation glass substrate is produced from a kiln at thousands of degrees Celsius, with a length and width of several meters and a thickness of up to 0.3 millimeters, about the thickness of a piece of paper. The surface roughness must be controlled at the micrometer level. Throughout the entire molding process, the glass surface does not come into contact with any substances other than air, and is naturally cooled for molding. Any small surface defects can lead to defects in subsequent film processes, directly affecting the yield of the panel.
For a long time, there are three multinational companies in the world that have the ability to produce high generation display glass substrates on a large scale and stably, namely Corning, Japan's Asahi Glass (AGC), and Electric Glass (NEG). The so-called 'generation' refers to the size grade of the glass substrate. The area of the 10.5 generation glass substrate has significantly increased compared to previous generations, enabling optimal cutting solutions for large-sized panels such as 65 inches and 75 inches. The glass utilization rate can reach up to 96%, significantly reducing unit production costs and providing important support for the large-scale popularization of large-sized televisions.
At present, the mainstream 10.5-generation glass substrate has a single area of over 9 square meters and can cut 8 pieces of 65 inch or 6 pieces of 75 inch TV panels at once.
Corning's leading position in the field of glass substrates is mainly due to a core technology called "melt pull down". Before the emergence of the melt down process, glass substrates were mainly manufactured by float glass process, which is similar to floating a layer of oil film on the water surface, and the glass liquid floats on the surface of the tin liquid to form.
The problem with float glass is that a small amount of tin ions will seep into the side of the glass in contact with the tin surface, affecting the surface quality, and requiring additional grinding and polishing treatment in the future.
In 1964, Corning scientists Stuart Dockerty and Clint Shay developed this technology after years of research. The principle is to let molten glass flow into a V-shaped groove, and the glass overflows on both sides of the groove and converges at the bottom, using gravity to naturally stretch and form in the air. Throughout the process, the glass never comes into contact with any solid surface, and the original surface quality of the finished product is extremely high, eliminating the expensive grinding and polishing steps in traditional processes.
The technology of melting and pulling down enables Corning's glass substrates to maintain a leading position in surface quality, thickness uniformity, and dimensional accuracy for a long time.
For over 60 years, Corning has continuously iterated on this technology.
Mu Boyuan said that from the earliest 3-inch LCD to today's ultra-thin 10.5-generation glass, Corning has been seeking breakthroughs in precision, flatness, thickness, and size.
Taking the 10.5 generation as an example, a glass substrate is about 3 meters by 3.3 meters, with an area larger than two extra large double mattresses, and the thickness is still only a few millimeters. The uniformity of the entire glass thickness and surface flatness must meet extremely high precision requirements. At the same time, high-tech inspection equipment based on Corning's proprietary algorithm will be used in the manufacturing process, which can scan subtle defects on a 10.5-generation substrate that are difficult to detect with the naked eye within seconds.
The technology that can achieve such precision on this size is still rare worldwide.
Investing so much money in the development and continuous improvement of a technology makes it crucial to protect intellectual property rights, "he said.
The core of the intellectual property dispute between Corning and Rainbow lies in this molten pull-down technology.
At the end of 2024, Corning first filed a civil lawsuit in China, accusing Rainbow of infringing on the trade secrets of Meltdown. Corning is currently continuing to advance its trade secret lawsuit against Rainbow in China.
Corning's decision to sue in China first and then initiate the 337 procedure in the United States means that its rights protection is not only targeted at the US market, but also covers the main regions where rainbow glass substrates are sold.
At the same time, Corning has initiated two 337 investigations with the ITC under US law, the first focusing on trade secrets related to the melt down process and the second on glass formula patents.
Once the 337 investigation confirms infringement, the ITC can issue an exclusion order to prohibit the infringing party's related infringing products from entering the US market.
In April of this year, the ITC administrative judge made a preliminary ruling on the patent case, determining the validity of Corning's patent and the infringement of Corning's patent by the "615" material used by Rainbow. On July 23rd, another administrative judge made a preliminary ruling on the trade secret case, determining that Rainbow illegally obtained and used trade secrets related to Corning's melting and pulling equipment and processes used in display glass manufacturing.
Mu Boyuan believes that the two preliminary rulings once again confirm the value of Corning's intellectual property rights in the field of display glass, whether it is patents on glass components or technical secrets involved in the melt down production process. The results of the two preliminary rulings are consistent with what we have been communicating with our clients all along. The next step will be to enter the final ruling stage according to the ITC process, and we are always confident. ”
He said that Corning's legal action is to protect intellectual property rights from the source, "to ensure that Corning can continue to thrive in the Chinese market and even the world, and to have a good development with our close cooperating customers
Patents have a time limit, while the protection of trade secrets does not have a predetermined time limit
After the preliminary ruling was announced in April, Rainbow expressed its position through multiple media outlets, stating that its current 616 formula has been deemed non infringing by the ITC. Its previous 615 formula was discontinued as early as 2024, and the patent involved will expire in October and November 2026, with limited actual impact.
Mu Boyuan responded to this and the preliminary ruling of the patent case determined that Rainbow's 615 formula infringed on Corning's valid patent rights, confirming the existing infringement facts. The intellectual property requested for protection in another case is different from the formula patent, which is a trade secret related to the melting and pulling equipment and process used for glass manufacturing. The illegal use of Corning's technology secret to manufacture glass will still constitute an infringement of this intellectual property.
Based on this, it is still necessary to evaluate whether using the 616 formula for Rainbow can solve the relevant problems in conjunction with the relief measures ultimately determined in the trade secret case.
Patents have a time limit, while the protection of trade secrets does not have a predetermined time limit.
Rainbow mentioned that the involved patents in the patent case will expire in the fourth quarter of 2026, but the protection of trade secrets is not limited by the validity period of the patents. Formula patents and process trade secrets are two independent intellectual property rights, each with its own protection logic. Simply put, the formula is "what materials are used to make glass", and the process is "how to make glass". Even if the formula patent expires, the trade secrets involved in the manufacturing method are still protected by the Trade Secrets Law.
Mu Boyuan said that Corning welcomes fair competition, especially competition based on respect for intellectual property rights.
Fair competition drives Corning to be more creative, efficient, and provide more value to customers. In his view, protecting intellectual property rights is not only about the interests of a company, but also about whether the entire industry can maintain sustained innovation momentum. Corning's footsteps in protecting its intellectual property and the actions we take will not stop, and we will continue to do so firmly
The next 20 years
In 2005, Corning cooperated with BOE to establish the first display glass substrate factory in Chinese Mainland. At that time, China's panel industry was just starting, and BOE put into operation the first domestic 5th generation TFT-LCD production line.
In 2025, Corning celebrated the 20th anniversary of its display business entering China. In the past 20 years, China's panel industry has grown from almost blank to the largest market in the world. Chinese Mainland currently accounts for about 78% of the global LCD panel capacity.
Corning has invested over 6 billion US dollars in the field of display technology in China, establishing 6 wholly-owned production factories, 2 joint venture factories, and 1 logistics distribution center, with a display technology team of nearly 3000 people in China.
Including all business segments such as optical communication, mobile consumer electronics, environmental technology, and life sciences, Corning's cumulative investment in China has exceeded 9.5 billion US dollars, with a total of over 10000 employees.
All Corning 10.5 generation factories are built adjacent to customers, achieving seamless transfer of glass substrates through corridors. As glass substrates are fragile and ultra large precision products, any vibration during transportation may cause irreversible damage. Building factories adjacent to customers is the most effective way to reduce risks.
In 2017, BOE laid out its production capacity for 10.5-generation large-size panels, and Corning's world's first 10.5-generation glass substrate production line was launched in collaboration with BOE, enabling single glass substrates to cut mainstream large-size panels such as 65 inches and 75 inches in the most economical way, significantly improving material utilization and production efficiency, and promoting the development of large-size displays into a new stage of scale and popularization.
In 2022, Corning will relocate the global headquarters of its Display Technology division to Shanghai. China is also the only market outside the United States where Corning has synchronized its layout of all core business segments and emerging businesses.
The scale of China's display industry today relies on panel companies achieving global first in the midstream, while upstream materials have partners such as Corning building factories locally, collaborating on research and development, and continuously investing. The efficiency of the supply chain comes from specialized division of labor, and it is impossible for every link to be independently completed by one enterprise or one country. The experience of the past twenty years has proven that open cooperation is more efficient than closed substitution.
Mu Boyuan said that Corning is not fighting alone, but has a very close cooperation with local customers, and Corning supports the sustained growth of the local display market.
Since 2005, the cooperation between Corning and BOE has lasted for 20 years, experiencing multiple rounds of capacity expansion. Corning's factory location has always been centered around BOE's production line layout.
In May 2026, both parties signed a new memorandum of cooperation to explore new opportunities in advanced consumer electronics and digital infrastructure. In June, Corning CEO Wei Wende personally visited TCL Huaxing in Shenzhen. Corning has also maintained long-term cooperation with panel companies such as Tianma, Huike, and Weixinnuo, and the cooperation areas are expanding from display to more industrial directions.
Mu Boyuan said that he has been working in Shanghai for a year and a half and is deeply impressed by the efficiency and continuous upgrading ability of China's supply chain. Glass is becoming a key material in more and more industries due to its advantages in size stability and mechanical properties. "Made in China is changing. Made in China today stands for advancing quality and innovation.”（ Chinese manufacturing is changing. Today's Made in China represents leading quality and innovation. ）
Mu Boyuan said, "China continues to strengthen intellectual property protection, especially in emerging industries and technology intensive fields, which will significantly enhance the attractiveness of its innovation environment to foreign-funded enterprises. For technology driven multinational companies like Corning, continuously improving intellectual property protection will also provide confidence guarantee for us to continue introducing advanced technology and working closely with local customers, suppliers, and research partners
For over forty years, Corning has continuously introduced the latest generation of display glass manufacturing technology into China, growing together with Chinese customers. Mu Boyuan said that precisely because of this, Corning values intellectual property protection even more and hopes to continue bringing more advanced technologies to China in a fair competition environment.
The display industry is a microcosm of China's manufacturing industry going global.
In this field, Chinese enterprises have transformed from pursuers to the world's largest producers in 20 years, and long-term investment from upstream and downstream partners is an indispensable part of it.
For the entire Chinese display industry chain, how to maintain a competitive environment that international partners are willing to continue investing in while promoting localization may be a more long-term issue than any lawsuit.
