Technological Breakthroughs in Flexible Transparent Film Display Products are Urgent

Posted by

On 02/19/2025

Abstract: This article provides a comprehensive analysis of the rigid market demand, current technological progress, and key challenges related to flexible transparent film display products in the emerging display technology sector. It also proposes potential directions for technological innovation and strategies. By comparing existing technologies, this paper highlights key areas for future research and development trends, and explores the market positioning and paths for technological breakthroughs. Finally, it provides recommendations and strategies to promote growth in this field.

Keywords: Flexible Displays; Transparent Films; Technological Breakthroughs; Material Innovation; Manufacturing Processes

Table of Contents

Introduction

1.1 Research Background and Significance

In the past year, the display industry has faced significant challenges, yet new development opportunities are emerging. In 2024, companies engaged in the research and production of flexible LED transparent display products entered a critical phase of market validation. Faced with fierce domestic and international market competition and economic pressures from the tightening of construction projects within the country, industry growth is under considerable strain. Three major trends have emerged in the sector:

The growth momentum of the industry is shifting. The profit margins of mature products are being squeezed, requiring companies to adopt more refined operational management practices. Meanwhile, the market penetration of differentiated innovative products is increasing, with companies actively seeking entry into high-growth areas. Businesses offering multi-tiered, comprehensive solutions are better positioned to adapt to market changes.

The trend of industry consolidation is intensifying. In 2024, small businesses within the LED display supply chain are facing mounting survival pressures. Many are exploring transformation paths, while mergers and acquisitions in the sector are accelerating.

From the consumer perspective, cost control in urban outdoor nighttime display projects has become a prevailing trend. Ensuring the protection of livelihoods, salaries, and ongoing operations has become a crucial factor determining the survival of companies.

Based on annual research, it was observed that the sales of LED flexible transparent film display products in 2024 experienced a drastic decline, dropping by 50%. This dramatic fall is not solely due to the broader economic environment but can be attributed to the inherent product defects, technical flaws, and poor quality control that have resulted in a market disaster for what was once a promising display technology.

1.2 Domestic and International R&D Progress

In today’s rapidly evolving technological landscape, a revolution in visual experiences is quietly unfolding. With breakthrough advances in flexible transparent film display technology, we are on the brink of entering a new era where “everything can bend.” Behind this visual feast, key technologies, materials, and manufacturing processes are driving the industry toward an exciting golden opportunity.

As technology advances and consumer demands become more diversified, flexible transparent film display products have emerged as a new favorite in the display technology field. Their technological breakthroughs play a vital role in advancing related industries. Imagine being able to fold your phone like a piece of paper and place it in your pocket or bag. On the subway, you can open a flexible, curlable electronic magazine for reading and downloading. Even your car’s windshield could instantly transform into a high-definition display screen. These possibilities are becoming a reality as flexible display technology matures, transitioning from science fiction to everyday life.

Flexible transparent film display technology refers to screens that not only have the crystal-clear transparency of glass but can also bend, fold, or twist without affecting the display quality. This revolutionary technology overcomes the limitations of traditional rigid displays, offering unprecedented freedom for electronic product designs. Whether OLED (Organic Light Emitting Diode), MicroLED, or Quantum Dot technologies, there is continuous exploration to integrate these with flexible substrates, aiming for lighter, thinner, more transparent, durable, and energy-efficient display solutions.

Globally, flexible transparent film display technology is rapidly developing, though core technologies remain under the control of a few companies. The research on LED flexible transparent film display products began in South Korea, and was introduced to China in 2018, with companies in Shenzhen and Shanghai actively involved in R&D. By 2022, pilot production ramped up, but due to immature materials, processes, and technologies, the market became chaotic, and the product’s application scope remained unclear.

Currently, China leads in the R&D of LED flexible transparent display technology and products. While these products are still in the trial production stage, they have a significant market share globally. Flexible transparent film display technology: the future is here, and it’s within reach.

1.3 Current Market Situation

Entering the 2020s, LED flexible display materials and products began to make their debut in the domestic consumer market, quickly gaining popularity through new media. Within less than a year, they garnered significant attention from developed countries abroad and rapidly entered international markets. The rise of flexible transparent film LED products, with their flexible, transparent, thin, energy-efficient, and customizable form factor, has revitalized the traditional display industry. Since 2021, many manufacturers have recognized the vast potential of the flexible transparent film display market and have quickly started production and planning.

However, due to the lack of systematic technological verification, and the rush to market without adequate testing or certification, many issues have surfaced as the product has entered various application scenarios. Problems such as dead pixels, black lines, yellowing, delamination, cracking, hardening, liquefaction, and decomposition have been frequently reported, severely restricting the growth of the flexible transparent display market. These problems have hindered high-quality development and independent innovation, leading to a sharp decline in the sales of flexible LED transparent film products in 2024.

Many leading research and production companies have attributed the shrinkage of market scale to the broader economic environment. However, the root cause lies in the inherent flaws and technical defects of the product. A deep reflection on the underlying issues and a heightened focus on technological paths are essential. We urge leading companies in the flexible transparent display sector to quickly adopt modern technological materials and manufacturing processes to improve product production, adjust material combinations, increase R&D investment, and enhance technological breakthroughs. Only through these efforts can flexible transparent display products return to a path of rapid growth and move towards healthy development.

Overview of Flexible Transparent Film Display Technology

2.1 Development History of Flexible Display Technology

From the early LED silicone flexible display modules to multi-layer PCB hollow matrix display products, and now to organic film flexible transparent display materials, flexible display technology has undergone significant development. Innovations in new materials and packaging systems are calling for the introduction of new processes and technologies. The concept of transparent displays cannot be replaced by conventional display thinking or traditional module experiences. Organic film transparent displays are high-tech products that integrate microelectronics, optoelectronics, computer technology, and information processing technology. They are supported by interdisciplinary foundations in physics, materials science, chip packaging, and organic chemistry.

Ignoring scientific principles and blindly cutting corners in production are the primary reasons behind frequent failures and pixel malfunctions in flexible transparent film LED displays.

2.2 Basic Principles of Transparent Film Display Technology

LED flexible transparent film materials are a subset of transparent screen products. These materials use display LED chips or RGB bare chips with flip-chip MIP (Metal In Package) COB (Chip on Board) packaging technology. The light board is made from organic polyester film and transparent high-molecular engineering plastics, with a surface-etched transparent mesh circuit. After surface-mount component bonding and packaging, the module is processed through adhesive application or other proprietary solid structure processes to create standardized modules.

The key advantages of this product include its lightweight, transparency, flexibility, ability to be cut to shape, high-definition brightness, and energy efficiency. It can be directly adhered to glass facades, following the shape without altering the original structure of the building or requiring any adjustments to the original curvature. When not displaying content, the screen becomes invisible, not affecting indoor lighting and leaving no visible installation traces.

The light transmittance of LED flexible transparent film materials can reach up to 75% (Note: The light transmittance of automotive-grade float glass is 93%. Some irresponsible companies and media falsely claim that LED flexible transparent film materials have a transmittance of over 90%, which is completely unfounded). LED flexible transparent film materials can deliver vivid, stunning image effects, enhancing the visual experience with powerful color stimulation and providing users with an exceptional sensory experience.

2.3 Application Areas of Flexible Transparent Film Display Products

Currently, LED flexible transparent film display products are primarily used in retail, stage decoration, media advertising, creative tourism, and landscape signage. These products are also expanding into sectors such as smartphones, tablets, wearable devices, in-car displays, and low-altitude economy applications, with growing market demand. The main market for these products is in China, followed by regions such as Europe, the Middle East, and Southeast Asia.

In the future, the mainstream market for flexible transparent film display products will not be in indoor flat display spaces. This is because the scale of indoor flexible curved transparent displays is limited, and most indoor transparent display needs are met by window displays or flat glass surfaces, which may not require flexible film installations. Alternative solutions, such as cost-effective OLEDs, matrix hollow displays, and grid screens, are more suitable for these applications. However, the main display areas for flexible transparent film products will be in outdoor curved shapes, landscape signage, in-car displays, low-altitude economy, and wearable displays.

Technical Challenges Faced by Flexible Transparent Film Display Products

Currently, leading domestic manufacturers of flexible transparent film display products face significant challenges in achieving the high standards required for transparency, flexibility, and durability. The root causes of these challenges stem from the pursuit of maximum profit, including: first, the use of SMD (Surface Mount Device) multi-wire “lamp-driver integration” modules; second, the selection of low-cost, low-performance PET (Polyethylene Terephthalate) as the substrate, which has poor thermal stability and leads to chemical damage during the reflow soldering process; and third, the use of non-structural adhesive bonding processes to circumvent the complex installation challenges in all-weather environments. These three fundamental flaws in material performance have severely constrained the healthy development of flexible transparent film display products, causing what should have been a promising new product to rapidly deteriorate within less than two years of market exposure.

The author’s investigation reveals that this issue is not a result of the economic climate. The situation should have been addressed when “Shenzhen Metro” removed the so-called “Crystal Film Screen” from a company named Ge Guang Optoelectronics. Unfortunately, this issue has been largely ignored by the industry.

3.1 Arbitrary Material Selection

The demand for high precision and mass production has made manufacturing processes increasingly complex, with cost control becoming a significant challenge. At present, many product manufacturers use pick-and-place machines to mount RGB (Red, Green, Blue) LED chips onto PET circuit boards. The LEDs are then soldered to the film material using low-temperature solder paste through reflow soldering to create various specifications of flexible transparent film display modules.

However, after extensive research, the author has found no academic institutions, professional organizations, or manufacturers’ alliances that have officially published or recommended PET as a suitable material for printed circuit boards (PCBs). Even authoritative search engines do not mention that PET can withstand the high-temperature reflow soldering process after modification. Based on practice and research, the author believes that regardless of the PET properties, solder paste, or control of reflow soldering temperatures and time, PET’s chemical damage and stress reset cannot be avoided. Even if no issues are exposed during factory aging tests, the material will eventually fail due to temperature fluctuations in the operating environment. Moreover, the future of flexible transparent Mini/Micro LED film display technology will certainly exclude PET from the Bill of Materials (BOM).

Today, PET will never, and in the future, should never be considered an ideal material for COB (Chip on Board) technology. This has become a consensus among polymer organic chemistry experts. For more details, please refer to the author’s article “Key to Flexible Transparent LED Film Display Products—Film Materials” published in the April 2024 issue (Issue No. 203) of Display World. Further discussion on this topic will not be included here.

3.2 Concealed Key Components

While PET’s suitability as a PCB material has been refuted, let’s now look at the so-called “lamp-driver integration” or “lamp-driver encapsulation” LED chips. This packaging method, originating from South Korea, involves integrating the RGB light-emitting chip and the driver IC within the same housing. After 12-14 points of wire bonding inside the housing, the chip is connected to the LED frame via four or six pins, creating an LED display module with “interruption-resumption” capabilities. Almost all flexible transparent film display manufacturers use the “interruption-resumption” feature as a selling point to demonstrate their products’ “high-end” qualities.

What they fail to realize is that the use of “lamp-driver integration” chips essentially ensures that “interruption” will be a common occurrence. If “interruption” were not a regular issue, why would there be a need for “resumption”? In contrast, traditional displays, both domestically and internationally, rarely experience such interruptions. More concerning and frustrating is that the “lamp-driver integration” design can never achieve small-pitch (Mini LED) or micro-pitch (Micro LED) displays. Even if small-pitch modules are created, they will not be transparent and will operate as “electric ovens.” Thus, the “lamp-driver integration” chip, from its inception, is a defective product.

3.3 Disordered Production Processes

Next, let’s discuss the so-called “no structure, no adhesive, no programming, just plug and play” encapsulation process used in film screens. Whether they are “lamp-film screens” or “crystal-film screens,” most manufacturers market them under the misleading label “crystal-film screens.” However, in real-world applications, nearly all of these products are installed with the “plug and play” concept, disregarding environmental factors such as geographic location, temperature, and climate. This leads to significant issues in various environments, such as daytime temperatures reaching 40°C (with temperatures on glass windows exceeding 76°C), nighttime temperatures dropping to 9°C in the Gansu desert, or car-mounted screens exposed to temperatures above 65°C and sudden temperature drops of 40°C.

Frequent temperature fluctuations cause chemical reactions between the PET modules and the adhesive layer (PET is chemically known as polyethylene terephthalate, a polymer compound). The adhesives used, especially those containing unsaturated organic compounds like acetylene, react easily with substances such as the silicone encapsulant used in “lamp-driver integrated” designs. In an oxygen-rich environment, this leads to the deterioration of the material’s appearance. The image below shows a display product installed in a vehicle a year ago by a certain technology company, where the adhesive has completely yellowed, and the adhesive has severely liquefied, flowing into the door, causing the power window mechanism to jam.

It is important to note that since flexible transparent film display technology was introduced to China from South Korea, it has never undergone scientific evaluations or product technical reviews by any formal institutions, nor have certification or testing reports been issued. Nevertheless, it was hastily introduced into the consumer market and was later promoted as “black technology” or “high-tech,” despite the lack of technical understanding and responsibility from certain individuals. The hype around these products led to irrational consumer behavior, causing what was once a promising innovation to quickly fade. By 2024, sales dropped by 50% compared to the previous year. The investigation revealed the primary cause: poor quality, requiring repairs weekly.

Analysis of Key Technological Breakthroughs in Flexible Transparent Film Display Products

The stability and lifespan of flexible transparent film display products in long-term use are critical factors in assessing their quality. Future Mini/Micro LED transparent screens will feature smaller sizes, higher brightness, lower power consumption, longer lifespans, shorter response times, and high-efficiency Mini/Micro LED chips. These will be paired with engineering-grade organic plastic CPI (Colorless Polyimide) or glass substrates. With the combination of high transparency in CPI and glass substrates and the superior display performance of Mini/Micro LEDs, transparent LED screens will achieve both high transparency and high-definition display effects, making their future development even more promising.

4.1 Development of New High-Performance Materials

Exploring new polymer materials, nanomaterials, and other advanced substances is essential for improving the optical performance and mechanical stability of these products. The challenge with substrate materials is that they must provide rigidity while also ensuring flexibility and resilience. Specifically, these materials must be able to return to their original shape after repeated bending—an essential feature for flexible transparent film displays. The materials used for foldable screen production must meet the requirements of flexibility, light transmission, and excellent surface scratch resistance.

Currently, glass is the primary base material for flexible transparent film display products. However, glass cannot bend or fold, which is why the properties of polymer engineering plastics have become ideal for flexible display substrates. Replacing the base material with a flexible film not only makes it foldable but also enhances the screen’s durability, while also making it lighter and thinner.

Transparent polyimide (PI) films offer excellent characteristics inherited from traditional PI, including high heat resistance, high reliability, bend resistance, low density, low dielectric constant, low CTE (coefficient of thermal expansion), and ease of micro-pattern circuit processing. Furthermore, they overcome the yellowing issue of traditional PI films, making them suitable for future flexible display technologies, as well as for applications in thin-film solar cells and flexible circuit boards.

As an essential substrate material in foldable smartphones and HUD (Head-Up Displays) in vehicles, competition between UTG (Ultra-Thin Glass) and CPI is intense. However, due to CPI’s mature mass production technology, it still maintains a price advantage. Currently, CPI remains a likely candidate for future mid-sized foldable displays.

Based on the current trends in the development of flexible transparent film display materials, the future of CPI as a substrate material looks very promising.

4.2 Innovation in Device Packaging and Integration Technologies

New packaging technologies and integration methods are essential for improving the overall performance and reliability of these products. Currently, a few leading flexible transparent film display material companies are trial-producing Mini LED bare chip flip-chip MIP (Matrix Integrated Packaging) COB (Chip-on-Board) display products. These companies use the latest high-speed die-bonding equipment to place high-efficiency RGB bare chips onto CPI substrates. To avoid interference from the refractive index of the transparent substrate, they apply damming technology during the COB dispensing process to encapsulate the RGB chip units and flip-mounted driver ICs in MIP packaging.

After soldering and AOI (Automated Optical Inspection) testing, a secondary coating and lamination process are applied to integrate the film substrate and protective film into a single unit, creating a high-strength, fully protected, ultra-light flexible transparent film display material. This process prevents issues such as lattice mismatch, bubbles, salt fog corrosion, short circuits, and other failures due to environmental factors. This product appears and feels like a standard plastic film but can display full-color, high-brightness images once connected to power and communication signals.

The future of flexible transparent film display materials will certainly involve true bare-chip packaging, marking the end of the era where “lamp-film screens” were falsely marketed as crystal film screens.

4.3 Research on Advanced Manufacturing Processes

Researching and optimizing key manufacturing processes, such as the installation structure of flexible transparent display films, has always been a major challenge for companies aiming to reduce costs and increase production efficiency. Currently, vacuum lamination of gel materials on light panels is not the best method for structural installation. Regardless of how manufacturers praise the ease and durability of this mounting technique, it cannot withstand the forces of nature or cope with the repeated temperature shocks over time. This remains a major issue for manufacturers of gel materials.

As of now, no adhesive material has been found that can offer complete UV resistance, high-temperature resistance, no liquefaction, no hardening, resistance to cracking, and oxidation prevention, while maintaining high transparency. Generally, the stronger the transparency, the faster the adhesive liquefies at high temperatures, and the higher its UV resistance and oxidation resistance, the lower the transparency.

Therefore, manufacturers are encouraged to invest more in research and development, focusing on overcoming the structural installation challenges of flexible transparent film display products. This involves moving away from large-scale encapsulation with adhesives and exploring new lightweight, robust, and fast-installation structural solutions. Not only would this reduce the hidden risks associated with encapsulants, but it would also save significant costs.

Designers can successfully suspend cast aluminum or iron boxes on building walls, but attaching lightweight flexible film display materials to glass is much more challenging. Is adhesive installation the only solution? Structural design innovation is not about repetitive operations—it is about creativity. A broad knowledge base is the foundation for structural design work, and clever combinations are the core of innovative structural design.

By using variant design methods, designers can start with an existing feasible structural plan and generate many alternative solutions. Through optimizing the parameters of these solutions, designers can find multiple local optimal solutions, and then compare them to find the best or globally optimal solution.

Many traditional design approaches, such as difficulties in creating long flexible transparent films, joining modules at only two ends, or using adhesive trays for car-mounted films, all reflect outdated thinking and a lack of structural innovation. We firmly believe that the new year will mark the beginning of a revolution in flexible transparent film display installations, breaking free from the constraints of adhesive structures and welcoming new, groundbreaking structural installation methods to usher in a new era for flexible transparent displays.

Innovation Trends and Development Directions for Flexible Transparent Film Display Products

5.1 Interdisciplinary Innovation Pathways

Integrating knowledge from materials science, physics, chemistry, and other fields is crucial for developing new pathways in flexible transparent film display technology. The maturation and stability of new transparent display technologies are closely linked to chip manufacturing processes, substrate properties, light source packaging, protective processes, application environments, and installation structures. Neglecting any of these factors can lead to irreparable losses in engineering projects.

The sustainable development of flexible transparent film display materials requires decision-makers and technical teams to adopt open-minded approaches. Collaboration across industries and disciplines is essential—avoiding isolated efforts. It is vital to creatively incorporate the latest technologies and new materials into the production and manufacturing processes, paving the way for flexible transparent film displays to advance toward miniaturization and ultra-micro applications.

5.2 Green and Sustainable Development Strategy

Emphasizing environmental impact assessments and promoting green manufacturing processes and recyclable materials are critical steps in the future of flexible transparent film displays. These materials are primarily polymer-based engineering plastics, and companies in the production and sales of these products must always be aware of environmental regulations, especially when exporting abroad. For example, the EN 15343 certification, which focuses on the traceability and recycled plastic content, is crucial for regulating recycled materials.

According to the UNE EN 15343:2008 standard, national standard organizations across European Union member countries are responsible for enforcing this certification. It covers the entire recycling process—from raw material waste management to final products—ensuring best practices to maximize environmental protection, waste management, and quality control.

Furthermore, on December 19, 2024, the European Commission will implement decision (EU) 2024/3176, amending decision (EU) 2022/602. The amendments primarily involve the recognition of the “International Sustainability & Carbon Certification (ISCC EU)” voluntary program for forest biomass, non-biological renewable fuels, and recycled carbon fuels. Other notable certifications include GRS (Global Recycled Standard), RCS (Recycled Content Standard), and OCS (Organic Content Standard), which help enterprises integrate recycled materials, reduce environmental harm, and meet buyer requirements, thus expanding international market opportunities.

These certifications are essential for companies manufacturing flexible transparent film displays to implement a green and sustainable development strategy and should be given adequate attention.

5.3 Smart and Multifunctional Product Design

Currently, integrating sensors, touch functionality, interactive features, and AI/AR (Artificial Intelligence / Augmented Reality) into display products is driving the trend toward smarter and more multifunctional products that meet future market demands. Augmented Reality (AR) technology, which relies on real-time computing and multi-sensor integration, overlays virtual information onto the real world, providing users with an exceptional interactive experience.

AR has a wide range of applications, including but not limited to electronics, services, manufacturing, e-commerce, and gaming. As the core technologies behind AR approach a breakthrough, the development of AI-enabled AR devices is entering a period of rapid growth. AI will enhance AR devices, making them lighter and more intelligent. For example, AR glasses use cameras and microphones to provide AI models with first-person perspective data, with results fed back to users via lenses or speakers, significantly enhancing the user experience.

Conclusions and Future Outlook

6.1 Summary of Research Findings

This article systematically analyzes the current technical status and development trends of flexible transparent film display products, offering guidance for future research.

The inherent limitations of the “lamp-driven hybrid encapsulation” method have reached their limits. This technology can no longer serve as a viable light source for small-pitch displays.

The use of PET as a transparent PCB substrate replacement has no scientific basis. Not only does it present significant risks, but it will also never be a suitable material for COB (Chip-on-Board) displays, neither today nor in the future.

The large-scale encapsulation of flexible transparent film light boards with gel is the root cause of frequent product quality issues and the need for repairs every week.

6.2 Significance and Value of Technological Breakthroughs

Technological breakthroughs will significantly drive the development of related industries, bringing both economic benefits and social impacts. It is hoped that flexible transparent film display technology will experience exponential development in 2025, leading to a disruptive leap forward.

6.3 Suggestions for Future Research Directions

It is recommended to strengthen basic research, promote industry-academia-research collaboration, and foster cross-industry, cross-disciplinary cooperation. Identifying new materials to address existing challenges and accelerating the application of technological breakthroughs will be crucial for the continued advancement of flexible transparent film displays.