The Supreme Court ruled that LG Chem's patent related to deuteration of organic light-emitting diodes (OLEDs) is valid. LG Chem is also in a civil suit with SFC, a domestic OLED materials company that filed the case, and the decision is expected to influence the court's judgment.
The Supreme Court's Second Division (presiding Justice Eom Sang-pil) said on Jun. 7 that it dismissed SFC's appeal in a suit seeking to invalidate the patent registered to LG Chem, in a ruling handed down on May 14.
The patent at issue is LG Chem's "Deuterated compounds for electronic applications" (Registration No. 1427457). The patent covers technology that improves light-emitting efficiency and lifespan in organic electronic devices such as OLEDs. It uses deuterated (Deuteration) aryl-anthracene compounds that replace ordinary hydrogen (H) atoms in a compound with deuterium (D), which has one more neutron. LG Chem purchased this patent from DuPont, a U.S. chemical company, in 2019.
In 2019, SFC petitioned the Intellectual Property Trial and Appeal Board, claiming the patent held by LG Chem was invalid. SFC argued the patent did not advance beyond prior inventions. In 2022, the board dismissed SFC's petition, saying, "Its inventiveness is not denied by the comparative prior arts."
SFC appealed to the Intellectual Property High Court to cancel the patent registration but lost again. The panel said, "This patent differs in technical composition from prior inventions," adding, "A person of ordinary skill could not easily make the invention by combining prior arts, so inventiveness is not denied."
After losing in the appellate court as well, SFC appealed to the Supreme Court. The Supreme Court dismissed the appeal, saying the lower court did not misunderstand the legal principles for assessing inventiveness.
SFC manufactures key materials needed to make OLED panels. Its main business is light-emitting materials such as blue hosts and dopants.
LG Chem and SFC are engaged in other legal disputes as well. Citing infringement of a patent related to OLED blue host materials, LG Chem sought damages in the tens of billions of won and demanded a complete ban on production and sales and the disposal of inventory.
SFC was established in Korea in Jul. 1998 under the name Sun Fine Chem, and in 2010 management control was sold to Japan's Hodogaya Chemical. In 2011, it formed a strategic partnership with Samsung Display.
As of the end of Mar. this year, SFC's equity is held 52.3% by Hodogaya Chemical and 29.7% by the SVIC No. 37 New Technology Business Investment Association formed by Samsung Venture Investment. Samsung Display invested in SFC through "SVIC No. 37." Current CEO Kim Yong-gwan, founder of Sun Fine Chem, holds a 7.4% stake.