Quest for Perfect Foldable 

2026 marks a defining year for foldables, not merely because Apple will debut its first foldable device, but more crucially because smartphone OEMs are zeroing in on the decisive battleground of the sector – crease elimination.  

Crease is a core pain point for foldables, serving as both a significant psychological barrier for potential buyers and a critical retention risk for existing users. According to a Counterpoint survey in China, it shows the crease issue across the entire user journey from purchase decision to long-term usage, widely regarded as a decisive factor impacting product experience, and demands technological improvement to enhance market acceptance. 

What Factors Need to be Improved When Using Your (Foldable) Phone? 

Below, we present a comparative analysis of three prominent foldable flagships, examining how each smartphone OEM tackles the persistent challenge of crease visibility. 

1. Samsung Galaxy Z Fold 7 

The Samsung Galaxy Z Fold7 set a new slimness and lightness record for Samsung's large-format foldables with its 215 gm weight, 8.9 mm thickness when folded, and mere 4.2 mm thickness when unfolded. The inner foldable display has made a significant jump to 8 inches with a crease that is less noticeable, and most of it comes down to Samsung Display and a variety of innovations that enabled this design. 

To achieve a seamless crease effect, Samsung Display has unveiled a series of advancements in foldable innovation. First, the device employs a thicker UTG (Ultra-Thin Glass) layer that enhances impact resistance and hinge-zone protection, while advanced stack-up engineering renders the overall display panel 30% slimmer than its predecessor, a counterintuitive achievement that decouples cover glass thickness from total module thickness. 

Second, a titanium alloy support plate supplants carbon-fiber-reinforced polymers (CFRP), delivering superior specific stiffness at significantly reduced mass. This structural weight savings enables the thinner panel architecture without sacrificing mechanical protection or longevity, as evidenced by the passage of a 500,000-cycle folding torture test. 

As is evident, the Galaxy Z Fold 7 still relies on "mechanical confrontation" via hinge and support structures to optimize crease control, whereas the following two foldables shift toward "stress management engineering", focusing on material stack optimization. 

2. OPPO Find N6 

As the first foldable phone to earn TÜV Rheinland's “Imperceptible Crease Certification”, the OPPO Find N6 controls crease depth to a level virtually invisible in daily use. Unlike the Galaxy Z Fold 7, which iterates upon proven legacy solutions, the OPPO Find N6 represents a fundamental reimagining of established folding technologies. 

Like conventional approaches, OPPO has also upgraded the mechanical architecture of its hinge. The Find N6 debuts a symmetric four-axis titanium alloy hinge, a significant upgrade from the three-axis design in the previous generation, reducing surface undulation from 0.18 mm to 0.1 mm and delivering a substantial improvement in flatness. 

It also integrates precision machining and 3D printing technologies to significantly enhance the hinge flatness of its support structure. It then fills structural gaps with polymer materials to prevent localized suspension and stress concentration, ensuring that the flexible display material maintains stable deformation despite repeated bending. 

In terms of material science innovation, OPPO upgraded the composition of the OCA (Optical Clear Adhesive) between each layer of the screen. OCA serves not merely as an optical adhesive for foldable devices; through elastic modulus engineering and compositional optimization, it exhibits pronounced viscoelasticity that stabilizes the central plane position and significantly mitigates stress concentration during folding. Furthermore, its micro-flow characteristics enable self-healing of microscopic surface irregularities accumulated through prolonged use, visually attenuating the perception of creases. 

Despite adopting CoE (Color on Encapsulation) technology to reduce inner panel thickness, this has concurrently elevated the internal screen's reflectance, falling short of the industry-leading 1.5% benchmark. 

3.Apple iPhone Fold 

Apple’s foldable iPhone is projected to launch in H2 2026, featuring a liquid metal hinge and crease-free display technology. Building upon the established solutions from Samsung and OPPO, Apple has introduced further design innovations. 

To achieve a crease-free effect, Apple intends to use a dual-UTG structure – in addition to the upper cover window UTG, the back plate (PET) beneath the PI substrate would also be replaced with UTG. This symmetric dual-layer glass architecture delivers superior overall rigidity and structural support. During screen folding, the upper and lower UTG layers jointly distribute stress, preventing the intermediate flexible layer from excessive compression or tension, resulting in a gentler, more rounded bend curvature that significantly mitigates crease formation. 

Another solution being considered is replacing the OCA/PET/HC&AF coating, which is laminated on top of the UTG cover window, with a high-viscosity coating layer. By eliminating the upper film, the crease can be reduced, while the high-viscosity layer also helps absorb shocks to the UTG. 

Although advancements in materials are the main driver for reducing creases, the mechanical structure remains crucial. Recently, several reports surfaced regarding potential manufacturing issues for Apple’s upcoming foldable OLED smartphone. Information from our sources suggests that several core bottlenecks remain during the qualification stage: 

• Liquid metal hinge yield rate at ~65%, below Apple’s ~85% target 
• Crease visibility and durability yet to meet Apple standards 

Despite these issues, current indications point to panel module shipments beginning in August, supporting a mid-September product introduction.