A circuit board.
Sergio Flores/Bloomberg
Surging demand for computer chips and related components amid the AI boom has boosted shares of ISU Petasys, a little-known manufacturer of printed circuit boards in South Korea, by 215% so far this year. The stock rise has made the company’s chairman, Kim Sang-beom, South Korea’s newest billionaire.
Kim, 64, directly and indirectly owns 17% of ISU Petasys shares. He also has stakes in other ISU Group companies: ISU Specialty Chemical, ISU Chemical and biotech firm ISU Abxis. Forbes estimates Kim’s net worth at $1.1 billion.
Based in Daegu, a city in southeastern South Korea, ISU Petasys makes multi-layer printed circuit boards that hold chips and other components for AI servers. “The reliability and quality of PCBs significantly impact the stability and performance of AI accelerator systems,” the company said in its financial report. Its competitors include Japan’s Ibiden, Taiwan’s Unimicron Technology and South Korea’s Samsung Electro-Mechanics.
“From GPU-centered AI infrastructure, we sense rising value in switches that enable faster data transmission across AI clusters. 800G switches are increasingly favored by end-customers,” JPMorgan analysts Jay Kwon and Sangsik Lee said in a September research note. “These switches utilise 40+ layer MLBs, which are ISU’s most advanced and lucrative product. Within the network segment, we expect 40+ layer MLB mix to be 22% in FY25E growing to 43% in 2026E.” Its customers include Alphabet, Nvidia, Microsoft, Cisco, Arista Networks and Celestica.
ISU Petasys owns four factories in Daegu and one in Hunan in central China. The company’s revenue rose 22% year-over-year to 494 billion won (about $350 million) in the first half of this year, while net income increased 76% from the previous year to 70 billion won in the same period.
ISU Petasys was established in 1972 and listed on the South Korean stock exchange in 2000. ISU Group acquired a controlling stake in ISU Petasys in 1995. ISU Group was started by Kim’s late father, Joon-sung, who founded South Korea’s first regional bank, Daegu Bank, in 1967. Joon-sung went on to serve as governor of the Bank of Korea, head of the Korea Development Bank and then as South Korea’s Minister of Finance and Economy. He also served as chairman of Samsung Electronics and Daewoo, which was once the country’s second-largest conglomerate before collapsing in 1999. Joon-sung died in 2007 at the age of 87.
Sang-beom joined ISU Group in 2000 as chairman, taking over the reins from his father. Before joining the family business, Sang-beom worked at Daewoo and was a lawyer at Debevoise & Plimpton in New York. He has a J.D. and an M.B.A., both from the University of Michigan, and a bachelor’s degree in business administration from Seoul National University.
Sang-beom is the latest Korean billionaire to make a fortune from the semiconductor sector. Other billionaires in the country include Kwak Dong Shin of Hanmi Semiconductor, manufacturer of equipment used to make high-bandwidth memory chips; and Lee Chae-yoon of Leeno Industrial, which makes parts for semiconductor-testing equipment that checks chips for defects.
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Source: https://www.forbes.com/sites/johnkang/2025/10/16/ai-chip-boom-propels-chairman-of-korean-circuit-board-maker-into-the-billionaire-ranks/
