SK Innovation's subsidiary ready for mass production of flexible cover windows

20, Jul. 2020

(Photo courtesy of SK IE Technology)
(Photo courtesy of SK IE Technology)

SEOUL, AJU - The subsidiary of SK Innovation affiliated with South Korea's third-largest conglomerate SK Group is ready for mass production of flexible cover windows that can replace glass displays for foldable and flexible smartphones.

SK IE Technology (SKIET), which makes separators for electric vehicle batteries, is a wholly-owned subsidiary of SK Innovation (SKI). The company has built a plant for flexible cover windows (FCWs) in Jeungpyeong, 90 kilometers (56 miles) south of Seoul. SKIET said its FCW increased durability by hard-coating colorless polyimide (CPI) to protect displays from external shocks.

"The successful supply of materials by global smartphone companies is the result of 'deep change' that SK Innovation has been pursuing and proves SK IE Technology's manufacturing technology and mass-production capability," said SK IE Technology CEO Roh Jae-sok.

CPI films are now widely used as an alternative to glass displays, which are more fragile and less flexible. They were used for Samsung Electronics' first foldable phone, Galaxy Fold. CPI films are prone to scratches and creases that are created when folded and unfolded repeatedly over a long time. In February, Samsung Display commercialized ultra-thin glass (UTG) as a window material for foldable displays. The first user was Samsung Electronics' second foldable phone, Galaxy Z Flip.

UTG offers many advantages over plastic or silicon. Hardened UTG is scratch-resistant and bendable and shows no signs of fatigue, making it an ideal substrate or encapsulant for OLEDs that ultimately make bendable or foldable displays possible.