Iljin Materials said on Tuesday that it has begun supplying 2 micrometers ultra thin copper foils to Samsung Electronics.
They are used for semiconductor packaging.
Japanese companies such as Mitsui previously dominated copper foils that are 2 micrometers-thin but Iljin began development of them in 2006.
Samsung requested that the company manufacture them after earthquakes in Japan back in 2011 threatened the steady supply of them. Iljin succeeded in commercializing them this year.
Iljin won a funding from the South Korean government in January. It will receive 5 billion won for research and development annually for the next five years.
Iljin began manufacturing copper foils in 1978.
Company CEO Yang Jeom-sik said the company will accelerate the development and filing of patents of materials for next-generation battery and 5G communication.