Foldable

An electronic device that adopts a structure in which the screen folds, a form factor that combines flexible OLED with a precision hinge to pursue both portability and a large screen.

Foldable

Overview

Foldable is a term collectively referring to electronic devices that adopt a structure in which the screen folds or unfolds, and mainly refers to smartphones, tablets, and laptops that combine a flexible OLED panel with a precision hinge mechanism. Its core value lies in securing portability at the size of an ordinary smartphone when folded and providing a large screen close to that of a tablet when unfolded. It was commercialized starting with Samsung Electronics' Galaxy Fold and Huawei's Mate X in 2019, and since then form factors have rapidly diversified into clamshell, book-type, and tri-fold types.

Main Content

Definition and Concept

Foldable is a name derived from "fold," meaning "to fold," and encompasses both a physically deformable display and the device body. It is distinguished from curved displays in which the screen merely bends, and a key requirement is that the screen and hinge must maintain durability even when the user repeatedly opens and closes the device in daily use. Typically, folding durability of more than 200,000 cycles is presented as a verification standard.

Core Technological Elements

  • Flexible display: Flexible OLED, in which an organic light-emitting layer is formed on a polyimide (PI) substrate, is the mainstay. Reducing the radius of curvature at the folding part while suppressing creases and burn-in is a technical challenge.
  • Cover window: Ultra Thin Glass (UTG) is mainly used, and some models use transparent polyimide (CPI) film. By processing glass to a thickness as thin as tens of micrometers, both flexibility and scratch resistance are secured.
  • Hinge: This is the mechanical heart of a foldable. Waterdrop hinges, multi-joint hinges, and others have been developed to distribute the stress applied to the screen when folded and to implement a free-stop function that holds the screen at a certain angle. Recently, reducing the number of hinge parts to lower weight and thickness has become a point of competition.
  • Battery and substrate: Technologies such as splitting and arranging the battery to avoid the folding area, or step batteries and flexible printed circuit boards (FPCB) that follow curved surfaces, are applied.
  • Camera: UDC (Under Display Camera) technology, which hides the camera beneath the display, is being applied first to foldables and is evolving.

Form Factor Classification

  • In-folding: A book type in which the screen folds inward. It is advantageous for protecting the large screen.
  • Out-folding: A method in which the screen folds outward, allowing part of the screen to be used even when folded.
  • Clamshell: A flip type that folds vertically. It is a form that reinterprets the sensibility of past folder phones, emphasizing portability and fashionability.
  • Tri-fold: A form that folds twice to expand the screen two- to threefold, which appeared in earnest after 2024.
  • Extendable: Methods such as slidable and rollable, which roll up or stretch out, are also in the research and commercialization stage.

Market and Major Manufacturers

Samsung Electronics has led the market with the Galaxy Z Fold and Galaxy Z Flip lineups, and Huawei, Motorola, Honor, Oppo, Vivo, Xiaomi, Google, and others have joined the fray. In particular, in the Chinese market, the rapid rise of Huawei and Honor is notable. Display supply is handled by Samsung Display, BOE, Visionox, and others, while Amphenol, KH Vatec, Fine M-Tec, and others participate in the supply chain for hinges.

Advantages and Disadvantages

Advantages include securing both portability and a large screen, usability for multitasking and split-screen use, and stand-style photography using the folding angle. Disadvantages pointed out include the high price, concerns about creases at the folding part and hinge durability, a body heavier and thicker than ordinary smartphones, relatively short battery life, and the hassle of managing the screen protector film.

Application Areas

Beyond smartphones, the technology is expanding to foldable laptops (e.g., Lenovo ThinkPad X1 Fold), foldable tablets, curved and variable displays for automobiles, wearable devices, and industrial equipment. Because the folding structure itself increases space utilization, it has become a differentiating factor for premium mobile devices.

Latest Trends

In 2024–2025, the foldable market shows two currents: "stagnating growth and restructuring." The growth rate of global foldable smartphone shipments slowed from high double-digit growth in the early days to single digits, while the market share of Chinese manufacturers rose rapidly instead. Samsung Electronics launched the Galaxy Z Fold6 and Flip6 in 2024, emphasizing integration with Galaxy AI features, a thinner and lighter design, and improved hinge and water resistance, and in October of the same year introduced the "Galaxy Z Fold Special Edition (SE)" with a thinner body and larger screen, responding to the ultra-slim competition.

Huawei unveiled the world's first mass-market tri-fold smartphone, the "Mate XT," in September 2024, leading form factor innovation, and Honor, Xiaomi, and others also joined the thickness competition with ultra-thin book-type models. Observations that Apple will release a foldable iPhone around 2026–2027 have been raised repeatedly, heightening both expectations and tension in the market at the same time.

Technologically, the key trends are ① ultra-slim designs under 10 mm thick, ② reducing the number of hinge parts and cutting weight, ③ improving UDC and foldable camera performance, ④ improving IPX8-grade water resistance and dust durability, ⑤ new-material cover windows to mitigate the fold crease, and ⑥ strengthening productivity features that combine on-device AI with a large screen. In addition, attempts to lower the price barrier through expanding budget lineups and revitalizing the used and refurbished market continue, and the adoption of foldable panels in IT devices (laptops and tablets) is also gradually increasing. In the future, "variable displays" combined with rollable and stretchable technology are expected to become the axis of competition for next-generation form factors.

Related Topics

  • [[Smartphone]]
  • [[Flexible Display]]
  • [[OLED]]
  • [[Samsung Electronics]]
  • [[Galaxy Z Fold]]