Invisible danger or unavoidable key component?
In brief
- Per- and polyfluorinated alkyl substances: PFAS are key process chemicals in the manufacture of TFT displays - especially in lithography, cleaning and protective coatings.
- REACH: Regulatory interventions such as the EU's planned PFAS ban could lead to obsolescence, supply bottlenecks and increased conversion costs.
- Supply chains: Early analysis and strategic planning are crucial to minimize technological and economic risks.
⏱ Estimated reading time: 4 minutes
The discussion about PFAS - perfluorinated and polyfluorinated alkyl substances - has gained enormous momentum in recent years. What was long considered specialized knowledge for chemists has now become an explosive topic for the entire industry. The substances are increasingly the focus of political and public attention due to their environmental and health effects. PFAS also play a role in the manufacture of TFT displays.
Where and why are PFAS used in TFT displays?
PFAS are a large group of more than 10,000 different compounds. What they have in common: exceptional chemical and thermal stability as well as water, grease and dirt-repellent properties. They are therefore used in numerous process steps in TFT production.
For example, in photolithography, a core process in thin-film transistor production. Here, fluorinated surfactants in photoresists and developers ensure uniform wetting of the surfaces - essential for the high precision that modern displays require. PFAS are also used in cleaning and etching processes, in barrier layers against moisture and even in liquid crystal formulations themselves.
Many of these areas of application are so technologically specialized that short-term substitutions are not easily possible. The particular challenge: PFAS often do not act as the main component, but in very small quantities - but with a decisive effect.
Regulatory pressure: the impending PFAS ban
The display industry is particularly alarmed by the increasing regulatory restrictions. The EU, in particular, is planning a far-reaching ban on almost all PFAS via the REACH chemicals regulation - with a few temporary exceptions. The reason: PFAS are extremely persistent, i.e. long-lasting, and can accumulate in the environment and in the human body.
For display manufacturers, module suppliers and OEMs, this means that a large number of established materials and process chemicals may no longer be permitted in the near future. Anyone developing a product today that is based on components with PFAS runs the risk of being confronted with obsolescence problems or delivery failures tomorrow.
What does this mean in concrete terms for TFT users and developers?
The consequences reach deep into the supply chain. Manufacturers must check which chemicals they use, whether their suppliers use PFAS and how quickly alternatives are available. For developers who install TFT displays in devices - whether in medical technology, industry or other durable goods - the question arises: how future-proof is the chosen display solution?
IPS TFTs (in-plane switching) are particularly affected. These generally require more complex manufacturing processes with an increased use of fluorinated chemicals for their higher image quality and stable viewing angles - for example in the structuring of the transistor levels or in the alignment layers. This makes these displays particularly susceptible to restrictions under PFAS regulations.
Long-term projects with high certification requirements, such as in the automotive or industrial environment, pose a particular risk. Here, a change in technology due to regulatory requirements can have serious consequences for product liability, approvals and maintainability.
Are there alternatives?
The good news is that PFAS-free materials are already available in some areas or are being developed. Some suppliers are working on newly formulated photoresists without fluorinated additives. Barrier layers and cleaning chemicals are also making progress. Nevertheless, the path to complete substitution in display production is technically challenging and not yet complete.
Some OEMs are therefore examining alternative display technologies such as e-paper, AMOLED or passive LCDs, which require less critical process chemistry. However, these technologies in turn present other challenges - for example in terms of service life, energy efficiency or temperature stability.
Technological foresight is now required
The PFAS discussion shows: The choice of a display is now more than ever a strategic decision. If you only look at price or short-term availability, you risk facing technical and regulatory problems in a few years' time. Manufacturers and developers should actively scrutinize their supply chain, remain in dialogue with display suppliers and find out about roadmaps for PFAS substitution.
In the long term, the industry will have to move towards more sustainable, environmentally friendly technologies that do not require high-risk chemicals. Those who help shape this change at an early stage will not only secure regulatory certainty, but also a competitive advantage in the market.
Read more: https://www.elektronikpraxis.de/eu-will-pfas-bei-ips-und-ffs-displays-verbieten-a-1097361/
