Chinese phone brands to use UTG in new foldable phones

Major Chinese phone brands are expected to supply ultra-thin glasses (UTG) as voer windows for their upcoming foldable smartphones, TheElec has learned.

Samsung was the first to shift away from polyimide films to glasses for the cover windows on its foldable smartphones.

The company’s original Galaxy Fold in 2019 used polyimide, but its subsequent smartphones Galaxy Z Flip and Galaxy Z Fold 2 launched in 2020 used UTG.

Chinese phone makers have only used polymide films for their foldable smartphones so far. 

Huawei Mate X2 and Xiaomi Mi Mix Fold that launched earlier this year used polymide films.

But foldable smartphones launching in the second half of this year by Chinese brands will use UTG.

Xiaomi will use UTG for its upcoming Mi Mix Fold 2 that will launch within the year. Samsung Display has supplied the 8.01-inch screen inside covered with UTG. The outer 6.52-inch screen is provided by CSOT. For the Mi Mix Fold, CSOT had supplied both the inner and outer screens.

Vivo is also planning to launch a foldable phone in the fourth quarter this year that will sport an 8-inch screen inside and a 6.5-inch screen outside. This product will also have UTG as the cover window. Samsung Display is providing the inside scree and BOE the outer screen.

Honor, which split off from Huawei, is also preparing a foldable phone called Honor Magic Fold with UTG applied. The 8.03-inch inner screen and 6.45-inch outer screen will be supplied by BOE. If the phone launches as planned, it will be the first time BOE is applying UTG to its foldable panel. BOE was testing mother glasses for UTG, a person familiar with the matter said.

Google is preparing a 7.6-inch in-folding foldable smartphone. It will also use UTG.

Meanwhile, Oppo is also preparing a foldable phone with a 7.1-inch inner screen and a 5.45-inch outer screen. The phone is likely to launch in 2022.

Samsung Display will supply the inner screen with UTG applied; the outer screen is provided by BOE. The main screen will also have low-temperature polycrystalline oxide (LTPO) thin-film transistor (TFT) technology applied.

The expanded use of UTG in foldable phones will also provide a chance for Corning to expand its share against Schott. Samsung currently exclusive procures mother glasses for UTG from Schott.

Last month, market research firm Display Supply Chain Consultants had said Samsung’s upcoming Galaxy Z Flip 3 will use UTG mother glasses from both Corning and Schott.

However, people familiar with the matter told TheElec that Corning’s yield rate for the UTG mother glasses were still low. The US company calls them bendable glass. Corning’s mother glass is around 50 micrometer thick. This is thicker than Schott’s mother glass supplied to Samsung that is 30 micrometer thick. Samsung is looking for a glass processing firm that can etch and process the 50 micrometer mother glass it procures from Corning.

Currently a foldable panel costs two to three times more (between US$150 to US$250) than a conventional flexible OLED panels (around US$80), the people added.