Isu Petasys said on Friday that its subsidiary Isu Exaboard was ending its printed circuit board (PCB) business.
Isu Petasys makes boards for telecom application while Exaboard had focused on flexible PCB and high density interconnectors for smartphones.
TheElec was the first to report on the exit in April.
Isu Petasys said the PCB business environment was worsening, which was causing it continuous loss.
The company was commencing the restructuring to focus on its core network PCB business, it said.
Isu Exaboard will close its operations by July 31.
Isu Exaboard had recorded five years of consecutive loss up to 2020. It recorded 120.9 billion won in sales, 10.8 billion won in operating loss, and 13.2 billion won in net loss for the entire year of 2020.
Sales was only 60% of what it made in the year 2017, while rate of losses tripled compared to then.