Samsung Starts $900 Million HBM Packaging Plant in Onyang

By Priya Raman

Samsung Electronics (005930) will invest 1.3 trillion won ($900 million) in a new high-bandwidth memory (HBM) advanced-packaging plant at its Onyang campus in Asan, South Chungcheong Province, with mass production targeted for May 2029.

At a groundbreaking on the 12th, Executive Chairman Jay Y. Lee said: “This place, where the work centered on simply assembling and testing general-purpose chips, will from now on be transformed into a cutting-edge HBM base that is the heart of AI semiconductors.”

Onyang No. 5 will contain a 31,000-square-meter cleanroom, a controlled production area for contamination-sensitive semiconductor work. The facility will specialize in HBM packaging as the campus moves away from its general-purpose chip assembly and testing work. Once complete, total campus floor area will reach 420,000 square meters from 270,000.

Why is Onyang changing?

The campus started as a chip assembly and testing line in 1991. It is now one of Samsung Electronics’ main back-end production bases, meaning the assembly and testing stages of semiconductor production. Lee said the 40-year transformation had taken the site from bare hills and unpaved roads to a plant that assembles, tests and completes semiconductors. He described semiconductors as industry’s staple crop and promised another advance at the groundbreaking.

HBM work gives Onyang a more specialized role. Samsung said the new plant will extend advanced-packaging capacity that had been concentrated in Cheonan. The stated purpose is to add capacity and meet rising demand for AI chips. The shift would broaden Samsung’s advanced-packaging footprint beyond Cheonan once Onyang No. 5 operates, although the company did not quantify the change in output.

How large is the investment?

The immediate project requires about 1.3 trillion won. The planned cleanroom accounts for 31,000 of the 150,000 square meters added across the campus. Over the medium to long term, Samsung plans to invest a total of 46 trillion won at Onyang to expand advanced-packaging facilities for high-bandwidth memory production.

The broader program extends beyond the dated Onyang No. 5 project. Samsung did not provide a breakdown of the 46 trillion-won plan, annual production capacity, equipment spending or customer allocations. The May 2029 date therefore sets the first clear mass-production target, not the completion date for the full Onyang investment program.

What does the government designation mean?

The groundbreaking makes Onyang No. 5 the first of the government’s three economic leap-forward mega projects to enter construction. Lee tied the investment to national industrial competitiveness. He said the president has told project review meetings that the global economy is entering a decisive period of disruption.

Lee characterized the government’s mega projects as a historic effort to redraw the future of the Republic of Korea. He also framed Samsung’s wider regional investment as an irreplaceable Korean success story. That language links the factory schedule to national industrial policy, but the announcement gave no terms for direct government finance or other public support for the project.

What role does public-private cooperation play?

“Under the president's leadership, if the central government, local governments and companies join forces, we will be able to create a turning point for the nation's great leap ahead,” Lee said.

The announcement did not provide a funding formula, permitting timetable or local-government commitment. Samsung’s 46 trillion-won capital commitment remains the only quantified program disclosed, with no public contribution quantified.

Where else will Samsung invest?

Lee said Samsung will pursue large-scale investment projects in Chungcheong, as well as Honam and Yeongnam. The current groundbreaking covers Onyang in Asan, within South Chungcheong Province. The company gave no regional allocations or separate project dates for Honam and Yeongnam.

The announcement does not provide packaging-unit volumes, yield targets, customer names or intermediate construction milestones. The near-term test is execution against the May 2029 mass-production target, while the missing data leave both the plant’s revenue contribution and the return on the 46 trillion-won program unquantified.