Samsung's new memory packaging line is due to start in June 2028, after the 2027 supply crunch

Samsung broke ground on Onyang Line 5 on 12 November, and its operating start is due in June 2028. SK hynix's own filing shows why a line's start date and its full spending can be years apart.

Samsung's new Onyang Line 5 high-bandwidth memory (HBM) packaging plant is due to start operating in June 2028. On that schedule it adds no output in 2027. CTOL's view: treat Line 5 as a 2028-and-later supply event, and 2027 tightness as unrelieved by it. The 46 trillion won figure attached to it comes from a 113 trillion won plan Samsung disclosed in July. The 12 November event was a groundbreaking.

Two Samsung dates, neither in 2027

Reuters reported that the line starts in June 2028, a year earlier than planned. A Seoul Economic Daily account targets mass production in May 2029. These are different milestones.

Supply is tight in the meantime. TrendForce, relaying Samsung's materials, reported that Samsung's 2027 HBM supply is effectively sold out. Samsung CFO Sooncheol Park said memory demand next year will "far exceed supply due to robust AI investment."

The 46 trillion won is a program, and the first 6 trillion is the plant

Seoul Economic Daily reported on 5 November that 46 trillion won of the July plan goes to HBM back-end plants over the medium to long term. Reuters quoted President Lee Jae Myung describing a 6 trillion won plant followed by about 40 trillion won of advanced equipment. CTOL reads 6 plus about 40 as the same program, with most of it equipment.

Seoul Economic Daily's 12 November report says the first 6 trillion won of Samsung Electronics' 60 trillion won plan for Onyang and Cheonan goes to Line 5. The same outlet's groundbreaking report carries a separate 1.3 trillion won (about $900 million) headline figure without saying what it covers; CTOL has not reconciled it.

SK hynix shows how late the equipment money can land

In a 10 July investment filing, SK hynix budgeted about 19 trillion won for its P&T7 advanced-packaging plant, including equipment and incidental costs. The filing's estimates, which may change, are 2.7 trillion won for 2028, 5.8 trillion for 2029 and 7.8 trillion for 2030. On CTOL's arithmetic, those three years are 16.3 trillion won, or 85.8% of the budget.

The same filing targets a first cleanroom at the end of 2027 and finishes equipment installation by 2030. SK hynix's project page targets a wafer-test line in October 2027 and wafer-level packaging in February 2028. The P&T7 figures are not Samsung's spending plan. They show that a packaging project's first milestones can come well before most of its money is spent.

SK Group targets a cleanroom at its Indiana plant by October 2028, with HBM production in the second half of 2029. That is roughly nine to 14 months later.

Counterpoint puts Samsung at 33% of HBM revenue in the second quarter of 2026, up from 15% a year earlier. SK hynix had 50% that quarter. Bernstein's Mark Li still prefers Samsung among incumbent suppliers. Bernstein cut its 2027 HBM price assumptions and expects memory prices in general to normalise in 2028. CTOL reads that as Samsung gaining share on existing capacity while Line 5 waits.

June 2028 is the test

An operating start is a project milestone. When Line 5's June 2028 start arrives, the evidence that it has become supply is installed monthly capacity, customer qualification and a ramp schedule. The May 2029 mass-production target is the next date after that. Until that evidence appears, the evidence favours treating Line 5 as a 2028-and-later supply event.