SILICON PENINSULA

Silicon Peninsula #008 — China is building glass substrate lines fourteen times the size of Korea's

Monday, September 28, 2026 · 5-minute read · Free edition

The tape

Seoul has been shut since Wednesday. Chuseok closed the exchange Thursday through Saturday, and the market reopens at 09:00 KST this morning to price four days of news in one session. The last Seoul print was KOSPI 7,164.80, +2.24%, with Samsung Electronics +2.92% and SK hynix +3.16%. (Hankyung)

New York kept trading. On Friday SOXX closed +1.17% at $572.68 against SPY +0.54% at $771.35 — chips ahead of the index again, but narrowly, and the leadership was concentrated in one name. SK hynix's Nasdaq line rose 2.78% to $191.56, a $993.6B market value — 0.6% from a trillion dollars, against 1.2% away when we last looked on September 22. The rest idled: Micron +0.16% ($1,082.28, $1.22T), Nvidia +0.22% ($225.07), AMD +0.22% ($630.63), Broadcom +0.70% ($352.81). (SOXX, SPY, SKHY, MU, NVDA, AMD, AVGO)

Three signals

1. China is building glass substrate capacity roughly fourteen times Korea's stated plan. WG Tech's Hubei subsidiary Tongeway put about 500m yuan (≈₩100B) into a first phase of 100,000 ㎡ a year, and has just begun a second phase lifting total investment to 1.216bn yuan (≈₩250B) for a target of 1m ㎡ a year. It cleared customer qualification in the first half of 2026 and already supplies in limited volume. SKC's Absolics runs 12,000 ㎡ a year in Georgia with 72,000 ㎡ planned for phase two — and phase one's yield stabilisation is late. BOE has a ~993m yuan pilot line, TCL's CSOT plans one this half, and 18-plus listed Chinese firms have entered the chain. Samsung Electro-Mechanics and Doosan's GlacSem venture is still in process validation; LG Innotek has not begun building a line. An industry source frames it as procedure: Korean firms validate each process before committing capital, Chinese firms install equipment, make product, and let the customer evaluate afterwards. Why it matters: #006 had JNTC committing 140% of its equity to a glass-via plant, #007 had Samsung quintupling glass carrier procurement toward 50,000 sheets a month by 2027. Both read as Korea reaching the glass era first. On volume it is not close — Korea's whole planned phase two is about 7% of one Chinese firm's target. The counter-argument is real, since glass substrates qualify per customer and an Nvidia or Samsung qualification outweighs square metres; but that argument has a shelf life, and China has already cleared one customer. (THE ELEC; also in its English edition)

2. The contract-length story now has a capacity number. Ahead of third-quarter results, Samsung is targeting 60–70% of memory output under long-term agreements and SK hynix has closed LTA talks with roughly a dozen major customers. Consensus: Samsung ₩199.1T revenue, ₩105.6T operating profit; SK hynix ₩94.1T and ₩74.1T; ₩189.87T combined. Estimates have come down over three months — Samsung −2.6% on revenue and −4.4% on profit, SK hynix −5.3% and −5.0% — which the report attributes to the won translation of dollar sales, not to memory demand. Mirae Asset models Samsung's DRAM ASP +16.5% quarter-on-quarter in Q3, slowing to +5.4% in Q4. Why it matters: #007 carried a sell-side account of customers requesting ten-year deals and we flagged it as unverifiable. This is the same trend measured from the supply side, where it is checkable. Note the trade: if two thirds of output is contracted while ASP gains slow to 5% by the fourth quarter, the spot upside that drove this re-rating is being deliberately sold for visibility. That is what an infrastructure asset looks like. It is also what a lower-beta one looks like. (Seoul Economic Daily)

3. A wafer-box maker is doubling capacity, which reads fab loading better than most guidance. 3S Korea is taking its Anseong FOSB line from 15,000 to 30,000 units a month. Wafer-carrier revenue was ₩5.18B in fiscal Q1 2026, up 165% quarter-on-quarter, after deliveries to a major Korean customer resumed following a two-year suspension over quality and service. Group revenue was ₩5.575B on ₩5.6m of operating profit — breakeven. Its Chinese arm, where it raised its Suzhou stake from 31.5% to 51% in July, targets mass production in late 2027 or early 2028 for a combined ~130,000 units a month. Why it matters: an FOSB is the box finished wafers leave a fab in, so demand tracks wafer starts that actually complete. A doubling is order-driven rather than announcement-driven — a useful cross-check on memory capex claims. The caveat is scale: a company whose record year was ₩17.1B of revenue is a signal, not an investment case, and 165% off a resumed customer is partly a base effect. (THE ELEC, 19:29 KST September 27)

Korea-only radar

What normally goes here is a filing, or a line nobody has translated. This week the pipeline was shut, and we would rather say so than pad it.

Number of the day

1,000,000 ㎡ a year — WG Tech's phase-two target for glass core substrate, against the 72,000 ㎡ Absolics has planned for its own phase two. Fourteen times. Korea's bet is that qualification, not capacity, is the moat. (THE ELEC)

Calendar

Silicon Peninsula is written from primary Korean sources every weekday morning (KST). Numbers are quoted from the cited source; where Korean outlets use won, we keep won. Founding-member Pro seats ($99/yr, first 50): reserve one here. Reply to this email with a company you want tracked. Forward it to someone who models memory prices for a living.

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