Polyimide

Researchers from the Korea 's SNU, KAIST and KIMM developed a new lift-off process for flexible OLED displays, based on graphene. The researchers term the new method GLLO, or Graphene Laser Lift Off.

The researchers placed a single-layer CVD graphene film between the polyimide film and the glass carrier. The graphene, with its ability to absorb ultra-violet light and distribute heat laterally, enables a clean lift-off without any wrinkles or residues. Using the GLLO method, the researchers successfully separated 2.9 μm thick ultrathin PI substrates without any mechanical damage or carbon residue left behind. In contrast, traditional methods left the substrates wrinkled and the glass carriers unusable due to stubborn residues. This breakthrough has far-reaching implications for stretchable electronics and wearable devices.

In late 2024 we reported several times that demand for Apple's iPad Pro devices is lower than expected, and the company reduced its OLED panel orders from both Samsung and LG.

According to a new report from Korea, LG may decide to start using its IT AMOLED production line to produce smartphone displays. The company looks to supply 70 million iPhone AMOLED displays to Apple in 2025, up from around 65 million in 2024 (and 52 million in 2023). Converting the IT AMOLED line to smartphone panel production will enable LGD to increase capacity without a large investment in new equipment.

UBI Research estimates that the foldable OLED market will reach 22 million units in 2023, and will grow to 61 million units by 2027, a CAGR of 29%.

UBI also published a forecast on cover material market for foldable OLEDs - this market will also expand, and will grow to $840 million n 2027. UBI says that the market share of ultra-thin glass will grow, as Samsung will only produce foldable OLEDs with UTG in the future, and other makers including BOE, CSoT and Visionox are developing UTG panels. 

LG Chem announced that it has developed a new PET-based foldable OLED cover film. LGC says its new film is thinner and more durable than both polyimide films and Ultra-Thin Glass, currently used in foldable OLEDs.

LG Chem designed new materials, which are coated on both sides of the PET film to strengthen its heat resistance and mechanical properties. The company says the new film withstands over 200,000 folding cycles.

Kolon Industries says that the company is supplying colorless polyimide (CPI) films to Xiaomi - used as cover windows for Xiaomi's latest Mi Mix Fold smartphone. Xiaomi sold over 40,000 such smartphones within one minute, and the company hopes to ship around 500,000 units in total.

Kolon says it is the only company that produces such CPI films, and the company says it also supplied films for Huawei's Mate X, Motorola's Razr and Lenovo's Thinkpad X1 foldable laptop - and will also supply to Oppo and Vivo for their own foldable devices.

UBI Research estimates that Ultra-Thin Glass (UTG) will hold a 80% market share in the foldable OLED panel cover material market. The rest of the market will adopt Polyimide films.

According to UBI, Samsung Display will only use UTG in its future foldable OLED displays. Transparent Polyimide films will be used in budget models, or for displays larger than 10" in size. BOE and CSoT currently use Polyimide films in foldable OLEDs, but both companies are looking to adopt UTG in future displays.

UBI Research estimates that foldable smartphone display makers will continue to rely on both Ultra-Thin-Glass (UTG) and Colorless Polyimide (CPI) films for at least the next five years.

UBI sees demand for CPI films will reach 4.3 million units in 2020 while demand for UTG will reach 3.5 million units. Demand for both products will grow and by 2024 it will reach 37.1 million units for CPI and 30.5 million for UTG.

Samsung Electronics's 2nd foldable smartphone, the Galaxy Z Flip, sports an ultra-thin glass cover, which replaced the polyimide one used in its previous foldable, the Galaxy Fold. The UTG glass cover is produced by Korea-based Dowoo Insys, who processes Schott's ultra thin glass.

According to a new report from Korea, Samsung Electronics wants to develop its own UTG cover, as it feels the Dowoo Insys UTG is still not robust enough and the company also wants to increase production yields and reduce costs. SE is already in talks with several glass suppliers for this project.

Samsung is working on its next foldable phone, which according to leaks will be called the Samsung Galaxy Z Flip. According to XDA's Max Weinbach, the new phone will be use ultra-thin flexible glass, instead of polyimide.

In November 2019 Samsung indeed signed an exclusive deal with Korea's Dowoo Insys to supply ultra-thin glass (UTG) for future foldable OLED devices. Samsung is aiming to switch to glass as its current foldable OLEDs which are protected by a plastic cover are highly prone for scratching and are very fragile.

Ireland-based OLED IP company Solas OLED has filed a lawsuit in the US (Texas) against Apple for patent infringements. The lawsuit mentions three patents (USPTO# 6072450, 7446338 and 7573068) that relate to the OLED stack, structure and circuitry (for example one of the patents relates to the formation of a backplane on a polyimide substrate).

Apple is of course not the producer of the OLED displays - but Solas says that Apple is accused of "making, using, selling, offering for sale, or importing products that infringe the claims" of its patents. Apple's OLED suppliers are Samsung (for the iPhone and MacBook Pro Touch bar devices) and LG Display (for the Apple Watch display).