Samsung Display plans to apply a new method to foldable organic light-emitting diode (OLED) by using liquid transparent adhesive (OCR) instead of transparent tape (OCA) to reduce processing time and material procurement costs, and plans to build a module production line in Vietnam, South Korean media reported.
STI, a display equipment company, has received an order (PO) for Samsung's display OCR inkjet printer, which will be used in the module production line at its Vietnam plant in preparation for full-scale production, industry sources said Wednesday.
STI reportedly received an order from Samsung Display for ink-jet OCR equipment for foldable OLED module process in 2020, when the equipment was installed at A1 plant in Cheonan, South Chungcheong Province.
It is well known that Samsung Display and STI have solved the problem of material flowing down a curved surface, which is the biggest difficulty of OCR application. However, it has not been confirmed which company has provided the OCR material for foldable OLED. Samsung Display purchased OCA from Samsung SDI.
"OCR has to do the inkjet and hardening [curing] process where it is needed, but the speed itself is faster compared to OCA, which is why Samsung invested in OCR," an industry official said.
OCA and OCR are both used in the display fitting process to connect the OLED panel to the cover glass. OCA has been the main material used in flexible OLED bonding, which is a method of pasting pre-cut scotch tape.
However, because thin film OCA must be fitted one by one, the processing time is long and the material cost is high. Ink-jet OCR materials are about 1 times cheaper than OCA, and only need to print the ink where it is needed, which can reduce processing time and material procurement costs.
In addition, the OCR device can print patterns while avoiding holes in smartphone cameras or speakers by spraying tiny ink droplets, reducing panel thickness and achieving a true zero-border foldable OLED with no top and bottom edges.
The industry estimates that Samsung Display buys more than 200 billion won of OCA materials every year. OCA market is mainly dominated by 3M of the United States. If ink-jet OCR successfully achieves mass production, import substitution effect can be expected.
