Flexible Cover Glass Enters the Era of Precision Engineering
May 06, 2026
Producing a uniform, ultra-thin, flexible, and flawless Uniform Thickness Flexible Glass (UTG) is already challenging-creating UFG with continuously gradient thickness is exponentially harder.
Zhang Chong, chief expert at China National Building Material Group Glass New Materials Research Institute, noted UTG has a uniform thickness, while UFG's strength lies in precise thickness control, achieving "thinner bending areas and thicker non-bending areas" via customized molds and gradient temperature control.
Rainbow Group's general manager Yang Guohong added UTG can use one-step or secondary molding, but UFG currently relies on secondary processing (chemical etching, mechanical polishing, laser ablation) due to uneven thickness, making production more difficult.
Yang admitted secondary processing for UFG suffers from low efficiency, low yield, high costs, and environmental issues-key barriers to mass production.
Industry data shows UFG's yield is below 50%, far lower than UTG's over 80%. Cost control will be critical in the next 1-2 years, with UFG focusing on the high-end market short-term.
A Corning representative confirmed its UFG-equivalent glass requires complex post-processing, highlighting manufacturing challenges.
Industry insiders agree "one-step molding" is key to scaling UFG, as it would boost efficiency, cut costs, and reduce yield loss.
Yang detailed three exploratory one-step molding solutions: thermoforming (suitable for mass production but high-precision requirements), overflow down-draw (lab-proven but not yet scalable), and 3D printing (immature, far from commercial use).
Direct UFG Manufacturing Faces Multiple Process Challenges
Even with one-step molding, UFG's thickness gradient poses challenges for chemical strengthening, a key step determining durability.
Bending areas (30~50μm) and non-bending areas (100~120μm) need different strengthening parameters; a uniform process causes flaws like warping.
Yang said regional strengthening-masking areas during processing is key to balancing flexibility and rigidity.
For gradient area stress control, industry solutions include multiple mixed-salt strengthening and "overall strengthening-local etching-overall etching."
Zhang added optimizing gradient curves, annealing processes, and material formulas also helps balance stress and performance.
Regional strengthening increases costs, but solutions are technically verified. Corning, Kaisheng Technology, and Rainbow Group are improving efficiency and yield.
Yang predicts directly formed UFG may enter the market in 5-10 years, aligning with UTG's shift to one-step molding.
Improving the Ecosystem Is Essential for Industrialization
UFG's industrialization requires close collaboration between UFG, flexible OLEDs, and ultra-thin hinges.
Zhang emphasized precise coupling of these components is vital, with core parameters like bending trajectory needing pre-design matching.
Yang noted UFG's non-uniform area accuracy must be ±5μm to fit precision hinges, reducing thickness differences to 20μm simplifies adaptation.
A supply chain insider stressed upstream-downstream collaboration and joint development are crucial, as high equipment costs also hinder capacity.
Industry insiders attribute Apple's willingness to adopt UFG to its supply chain integration, domestic suppliers need early joint development.
UFG's industrialization is a tough battle, but it drives Chinese high-end manufacturing forward, marking the era of "precision engineering" for flexible covers.
