SK hynix runs two Korean campuses with different jobs. Icheon holds the headquarters and the DRAM front end, in fabs numbered M10, M14 and M16. Cheongju holds NAND, the M15X DRAM line and both new buildings the board has approved for the legacy campuses since September 2025. Packaging and test run at both. The choice is between the site holding the corporate centre and the installed DRAM base and the site holding the NAND base and every new building.
Both campuses sit on the corridor mapped in the reference guide to Korea’s semiconductor industry. This piece covers what each campus holds, what the company’s own filings commit at each, and where a foreign supplier’s office, field engineers and demonstration capability belong.
Data current as of September 2026. Investment figures are taken from SK hynix’s filings on Korea’s DART disclosure system, with the receipt number and filing date beside each.
What Sits at SK hynix’s Icheon and Cheongju Campuses?
Front-end DRAM and the corporate centre at Icheon, NAND and the back end at Cheongju, with one large exception in each direction.
Icheon is the registered headquarters. SK hynix gives its address as 2091 Gyeongchung-daero, Bubal-eup, Icheon, Gyeonggi Province, on its own corporate site, read on 15 September 2026. The company held the M16 groundbreaking at its Icheon headquarters on 19 December 2018 and announced completion of M16 construction on 1 February 2021, so the newest Icheon fab is five years old. Korean trade press consistently describes the Icheon line-up as M10, M14 and M16, with M16 as the EUV-capable DRAM base.
Cheongju is in North Chungcheong Province, outside the Seoul metropolitan area entirely. The Elec reported on 13 January 2026 that SK hynix operates the M11, M12 and M15 NAND fabs there plus P&T3, which handles back-end work, and that the new P&T7 advanced packaging fab would sit in the Cheongju Technopolis industrial complex. The exception that matters most to a DRAM supplier is M15X. SK hynix announced on 24 April 2024 that it would produce new DRAM from M15X in Cheongju, and explained the siting in its own words: “Being located near the M15, which has been expanding TSV capabilities, the M15X is the best conditioned for optimization of HBM production.” Where that fits the stack is covered in the guide to the HBM supply chain in Korea, and the back-end capacity map sits in the guide to advanced packaging in Korea.
The back end is the part most often misplaced on a supplier’s map, because it runs on both campuses. When SK hynix announced P&T7 in June 2025 it already operated six packaging and test facilities across Icheon and Cheongju, per the Electronic Times and Today Shinmun on 24 June 2025. The Financial Post reported the same day that P&T1 and P&T4 sit at Icheon and P&T2 and P&T3 sit at Cheongju, with two further sites renamed P&T5 and P&T6, and that Cheongju is expanding P&T3 while it builds P&T7. Read that as a two-campus installed base with the new capacity landing on one of them.
M15X also carries a history worth knowing before you quote its dates. The project was announced in September 2022 for a site in Cheongju Technopolis, work was deferred through the memory downturn, and Money Today reported on 1 February 2024 that a resumption planned for that February had been postponed for a three-month review. The April 2024 board decision restarted it as a DRAM base. Chungcheong Times reported on 16 April 2026 that M15X had entered full operation, with industry estimates putting wafer input near 10,000 a month and rising, and The Elec reported on 24 December 2025, again citing industry sources rather than the company, that HBM4-bound 1b DRAM wafer input had been pulled forward to February 2026 from June.
Per-fab capacity is where a supplier’s plan usually goes wrong. SK hynix does not publish wafer capacity by fab, so the figures in circulation come from securities analysts and market research firms. Seoul Economic Daily reported on 30 July 2024, citing TrendForce, that M16’s monthly wafer input stood at roughly 100,000 and would rise by up to 80 percent by the end of 2025, and recorded that these were industry estimates the company declined to confirm. Treat any fab-level headcount or capacity number you are handed the same way, and ask whose model produced it.
What Do SK hynix’s Own Filings Commit at Each Site?
Construction money, on dated schedules, in amounts well below the headline totals that reach the trade press. The gap between the two is the single most common error in supplier planning documents.
Three filings define the current commitment. On 22 July 2026, SK hynix filed a new facility investment disclosure for Cheongju P&T7 (rcpNo 20260722800829) recording 7,093,100,000,000 won, 5.88 percent of equity, with an investment period running from 26 November 2025 to 31 December 2032. The filing states that the eighth board meeting of 2026 resolved to increase the construction investment amount in response to production growth and a shortened cleanroom opening schedule. On 7 August 2026, two filings followed: Cheongju M17 construction (rcpNo 20260807800602) at 19,100,000,000,000 won running to 30 April 2031, and Yongin semiconductor cluster second-phase fab construction, Phases 1 to 6 (rcpNo 20260807800613), at 35,224,600,000,000 won running to 31 October 2031. An earlier filing of 25 February 2026 (rcpNo 20260225801974) put 21,608,100,000,000 won into Yongin first-phase Phases 2 to 6.
Now compare those with the announced programme. SK hynix’s chief executive Kwak Noh-jung stated on 2 July 2026 that it would invest 100 trillion won in Cheongju, 80 trillion in the M17 NAND fab and 20 trillion in P&T7 and related advanced packaging. KED Global reported the 19 trillion won P&T7 figure on 13 January 2026 without separating construction from equipment. The filings cover buildings. The larger numbers cover buildings plus the tools that go inside them over several more years. Quote them separately, name which one you are using, and never add them together.
Every one of those filings carries the same two cautions in its own text: the investment amount may change with the progress of the investment and with changes in the business environment, and the start and end dates are planned dates that may change as the project proceeds. That is the issuer telling you, in a regulated document, that its own numbers are provisional.
The same discipline applies to reports the company has not confirmed. Answering a Korea Exchange inquiry on 9 September 2026 (rcpNo 20260909800559) about reported plans to sell a stake in its Chinese packaging plant, SK hynix said it was reviewing various measures to strengthen the competitiveness of its package business with nothing decided, and set a re-disclosure deadline of 8 December 2026. A 21 August 2026 answer on reports of a fab in Japan (rcpNo 20260821800524) took the same form, with re-disclosure due by 18 September 2026. A report is not a commitment until one of these filings says so.
Why Do the New Buildings Keep Landing in Cheongju?
Land and regulation, on top of the process logic. Across SK hynix’s DART facility-investment filings from September 2025 to September 2026, the only new buildings approved at the two legacy campuses were both at Cheongju.
Icheon sits inside the nature conservation zone (자연보전권역) of Korea’s capital region planning regime. The Seoul Metropolitan Area Readjustment Planning Act restricts specified development in that zone, and Article 9 of its Enforcement Decree (Presidential Decree No. 35811, promulgated 1 October 2025) sends the zone boundaries to Annex 1, which lists Icheon City first among the nature conservation zone municipalities. Article 13(1)2 of the same Decree makes an industrial land development project of 30,000 square meters or more a restricted development project there, and Article 14(1)3 permits one of 60,000 square meters or less where it clears review by the Seoul Metropolitan Area Readjustment Committee. The Ministry of Land, Infrastructure and Transport’s notice on applying adjacent development rules in the nature conservation zone, 고시 제2024-1075호, partially amended and in force from 6 January 2025, adds paragraph 5-3-5: where a local authority adopts a redevelopment plan for an existing cluster of factories, an industrial complex project may proceed in stages provided the total project area stays under 300,000 square meters, again subject to committee review.
Read who that binds before you act on it. These provisions govern the administrative agencies that approve development projects, so they shape how much industrial land Icheon can create and how fast. They place no restriction on a foreign company opening an office, hiring engineers or storing spares in Icheon.
The practical effect shows up in the size of what Icheon can offer suppliers. Seoul Economic TV reported on 19 June 2026 that Icheon City and Gyeonggi Housing and Urban Development Corporation had started the Daewol 2 general industrial complex at Gusi-ri in Daewol-myeon, 48,656 square meters, targeting completion in December 2027, and that the city intends to develop it as a semiconductor parts and materials zone linked with SK hynix, aiming at electronic components, electrical equipment and metal processing firms. That site sits below the 60,000 square meter line in the Decree. Icheon’s mayor told the Hankook Ilbo on 21 July 2026 that overlapping regulation makes it difficult to expand manufacturing facilities in the city, and described pursuing research-based industrial designation as the alternative route.
Cheongju has a different problem set. Cheongju City’s own industrial complex page, read on 15 September 2026, gives Cheongju Technopolis as roughly 3.8 million square meters in Gangseo 2-dong, Heungdeok-gu, with about 1.35 million square meters of industrial land, developed between 2007 and 2024. M15X and P&T7 both sit inside it. The city is buying its way into the next phase as well: the Asia Business Daily reported on 6 July 2026 that Cheongju had set up an investment support task force for SK hynix’s announced 100 trillion won programme, committing a fourth-stage, 27.8 billion won water project to deliver an additional 110,000 cubic meters a day of industrial water from June 2027 through 2.4 kilometers of new pipeline, and to work with KEPCO on substation and transmission capacity.
What Is the Travel and Response Geometry Between These Sites?
Two provinces, two transport spines, and a Yongin site that pulls toward one of them and not the other.
Icheon is in Gyeonggi Province and Cheongju is in North Chungcheong, so the two campuses sit under different provincial administrations and different regional infrastructure plans. Cheongju’s high-speed rail access runs through Osong, which Sejong City’s official transport page, read on 15 September 2026, puts at about 50 minutes from Seoul by KTX against about an hour and a half on the Mugunghwa service. Icheon has no KTX station and is served by the Gyeonggang Line, including Bubal station in the same township as the SK hynix headquarters, which the Hankook Ilbo’s 21 July 2026 report named among the station districts the city plans to develop.
The Yongin build changes the weighting. SK hynix’s cluster there is in Wonsam-myeon, inside Gyeonggi Province like Icheon, on the schedule set out in the guide to the Yongin semiconductor cluster. A team based for Icheon is positioned for Yongin in a way a team based for Cheongju is not, which matters because Yongin is where the front-end capacity of the 2030s is being built.
Campus adjacency cuts the other way too. On 1 June 2026, a fire started in a sixth-floor gas room connecting the M15 and M15X lines at the Cheongju campus, releasing fluorine gas measured at around 5 parts per million, with roughly 3,600 workers evacuated from the two fabs and eleven people taken to hospital, per Electronic Times and MBC reporting that day. SK hynix said the fire was extinguished immediately, that equipment operation was unaffected and that there was no production disruption. One incident in one utility room touched two lines at once. A supplier whose product feeds several buildings on one campus should plan its coverage against buildings, not against site names.
None of this settles response times, which are negotiated per tool and per customer. What Korean fabs actually expect from a service organisation, and what it costs to staff, is set out in the guide to after-sales service in Korean semiconductor procurement.
Where Should a Foreign Supplier Put Its Office, Engineers and Demo Capability?
Work from your product to a building, then to a province. Two rulings sit above the cases that follow.
Where the buying sits. SK hynix runs procurement as a corporate function, and the organisation sits above the individual campuses. Energy Economy Daily reported on 4 December 2025 that the 2026 reorganisation seated a procurement head under the Corporate Center, and The Elec reported on 27 March 2023 that the company had already split the procurement organisation into front-end and back-end units. The front door is a portal. SK hynix’s supplier portal carries registration, dealing items, buyer assignment and payment terms, and gives the Icheon headquarters address as its own, read on 15 September 2026. Supplier-facing business also travels, and the 2026 win-win growth council general meeting ran at a Seoul hotel on 20 April 2026, per Paxetv. Anchor the commercial relationship at Icheon and treat Cheongju as a second working location of the same buying organisation, which is why both campus names appear in descriptions of SK hynix procurement.
Where your people sit. This one is operator judgment, and it carries no statistic. The commercial office and the field-engineer base are separate decisions. Put the office where you can recruit bilingual commercial staff, host a visiting executive and reach an airport, which in practice means Seoul or the Pangyo and Bundang corridor. Put engineers within daily driving reach of the campus holding your tools, which is a different address and often a different province. Suppliers that collapse the two into one location usually end up with a well-staffed office and a badly covered fab.
Four cases cover the rest.
Front-end DRAM process tools and materials. Front-end DRAM now runs at two operating sites in two provinces, the Icheon fabs and M15X at Cheongju, which has been in full operation since April 2026. The question this group answers first is which of the two carries its installed tools, because that is what sets the service load. Where the answer is Icheon, one rotation also covers Yongin in the same province, which is where the front-end capacity of the 2030s is being built.
NAND, back-end and advanced packaging. This ruling turns on installed base at Icheon against new capacity at Cheongju. The installed packaging and test base is split between the campuses, so the near-term service load follows your own tool list before it follows a province. The new capacity is one-directional: Cheongju carries the NAND fabs, the P&T3 expansion and the P&T7 build. Weight a North Chungcheong base to that buildout, and keep Icheon inside reach for the lines already running there.
Facility and clean-process systems. Your buying windows are construction windows, and they are at Cheongju for M17 and P&T7 and at Yongin for Y1 and Y2. Specification happens years before tool-in, through the contractors described in the guide to Korean EPC firms on semiconductor fab projects, so the office that matters is the one that can reach a design team, not a production floor.
Demonstration capability. Running a process under production conditions without consuming a customer’s line is the constraint that stalls most evaluations. The shared testbed SK hynix is co-funding, Trinity Fab, carries a future target date and is still to open. Money Today reported on 11 August 2026 that it is due for completion in May 2027 in the Wonsam-myeon industrial complex of the Yongin cluster, carrying about 50 tools on 12-inch wafers. Its funding and tool count are set out in the Yongin guide above. A Gyeonggi base is worth weighting for demonstration capability on that schedule, and until the testbed opens the only demonstration route is a customer’s own line or your own equipment. Qualification then runs on its own clock, commonly 12 to 18 months, as the guide to the fab qualification process in Korea sets out.
Two disqualifications are worth reaching quickly. If your product only fits scopes already specified on the current phase at both campuses, the honest answer is to target M17 and Y2 and spend the interval on qualification and on a Korean partner. And if your Korea plan depends on a single office covering both campuses with same-day response on a production-stopping fault, price the second team or name a partner that already has one, because most foreign suppliers reach both campuses through a Korean entity holding the vendor code, on the criteria in the guide to choosing a semiconductor distributor in Korea. How SK hynix differs from Samsung as a buyer, including its supplier funding and payment programmes, is compared in the guide to Samsung vs SK hynix suppliers, and the equivalent Samsung site map is in the guide to Samsung’s Pyeongtaek campus.
Frequently Asked Questions
What is the difference between SK hynix’s Icheon and Cheongju campuses? Icheon is the headquarters and the DRAM front end, running the M10, M14 and M16 fabs, with M16 completed in February 2021 per SK hynix’s own completion announcement. Cheongju runs the M11, M12 and M15 NAND fabs, per The Elec in January 2026, and adds the M15X DRAM line beside M15. Packaging and test runs on both campuses, six facilities in June 2025 per the Electronic Times.
How much is SK hynix actually investing in Cheongju? Two figures exist and they measure different things. SK hynix announced 100 trillion won for Cheongju on 2 July 2026, 80 trillion for M17 and 20 trillion for P&T7 and related advanced packaging, covering buildings and equipment. Its DART filings commit construction money: 19.1 trillion won for M17 on 7 August 2026 and 7.0931 trillion won for P&T7 on 22 July 2026, both stated as subject to change.
Should a foreign supplier open an office in Icheon or Cheongju? Separate the two questions. The commercial office belongs where you can staff it, commonly Seoul or the Pangyo and Bundang corridor, and engineers belong near the campus holding your tools. Front-end DRAM now runs at Icheon and at Cheongju’s M15X. New NAND and packaging capacity is at Cheongju. Facility and clean-process suppliers sit near the design teams contracting M17, P&T7 and the Yongin fabs.
Do Korea’s capital region rules limit where suppliers can operate in Icheon? They limit industrial land creation, not your presence. Icheon sits in the nature conservation zone under the Seoul Metropolitan Area Readjustment Planning Act, whose Enforcement Decree restricts industrial land development projects of 30,000 square meters or more and permits smaller ones by committee review. Those provisions bind the agencies granting approvals. Opening an office, hiring engineers or holding spares in Icheon falls outside them.
Where to Take This
SK hynix’s two campuses reward suppliers who can name the building their product belongs to and the filing that funds it. The announced totals and the disclosed construction amounts answer different questions, and only one of them carries a board date.
Inquivix Technologies works with global semiconductor equipment, materials and clean-process companies entering Korea’s semiconductor market, covering representation, distribution, technical localization and qualification support at both SK hynix campuses. Route representation, distribution and technical localization questions to Inquivix Technologies. To work through where your product fits the Icheon and Cheongju buildout before that, contact Joon K Lee at joon@joonklee.com.
