IDM Captive Packaging

SK hynix · Samsung · Micron · Intel · Kioxia · SanDisk

Every HBM stack in an AI accelerator is assembled by the company that made its DRAM: SK hynix, with 50% of HBM in the second quarter of 2026, Samsung with 33% and Micron with 18%. All of it is assembled in Korea, Taiwan and Singapore. The first US HBM line, SK hynix in West Lafayette, Indiana, produces from the second half of 2029.

Where HBM stacks are assembled: SK hynix, 50% of HBM in the second quarter of 2026, at Icheon, a planned Cheongju plant and West Lafayette, Indiana from the second half of 2029; Samsung, 33%, at Cheonan and a new Onyang HBM fab; Micron, 18%, at Taichung, a new Singapore plant and an undated US plant. No HBM stack is assembled in the US today. WHERE HBM STACKS ARE ASSEMBLED SHARE OF HBM, 2Q 2026 50% SK hynix Icheon Operating Cheongju P&T7 Planned West Lafayette, IN 2H 2029 33% Samsung Cheonan Operating Onyang New HBM fab 18% Micron Taichung Operating Singapore Ramping 2026-27 US No date Made abroad US planned NO HBM STACK IS ASSEMBLED IN THE US TODAY. SHARES: COUNTERPOINT, SEPTEMBER 2026.
HBM leader
SK hynix, 50%
Samsung HBM share
33%
Micron HBM share
18%
US HBM assembly
2H 2029
US captive packaging
Intel Fab 9
Hub
Fabs

IDM operators

Integrated Device Makers That Package Their Own Chips

An integrated device maker (IDM) designs, fabricates and packages its own chips. Its back end serves its own products first.

IDM captive packaging operators
IDM (HQ)Back-end plantsPosition
SK hynix (Icheon, South Korea)Icheon and Cheongju, South Korea; Chongqing, China; West Lafayette, Indiana from 2029HBM leader; packaging budget of KRW 20 trillion in Cheongju, including the P&T7 plant
Samsung (Suwon, South Korea)Cheonan and Onyang, South Korea; Suzhou, ChinaShifting Cheonan to HBM and sending conventional memory modules to outside suppliers; new KRW 6 trillion Onyang HBM fab
Micron (Boise, Idaho)Taichung, Taiwan; Xi'an, China; Penang, Malaysia; Singapore HBM plantThird HBM supplier; US HBM packaging planned only after its second Boise fab, with no date
Intel (Santa Clara, California)Ho Chi Minh City, Vietnam; Penang and Kulim, Malaysia; Chengdu, China; Costa Rica; Fab 9 in Rio Rancho, New MexicoOldest captive back end in the industry; Fab 9 and Penang also serve Intel Foundry customers
Kioxia (Tokyo, Japan)JapanNAND packaging next to its Yokkaichi and Kitakami fabs
SanDisk (Milpitas, California)Shanghai, China; Penang, MalaysiaSpun off from Western Digital in February 2025; Kioxia NAND joint venture partner

HBM stacks

No OSAT Assembles HBM Stacks

SK hynix, Samsung and Micron each stack, bond and test their own HBM before shipping it to TSMC for CoWoS. In the second quarter of 2026, SK hynix held 50% of HBM, down from 58% a quarter earlier, as Samsung rose to 33% on HBM4 shipments for NVIDIA Rubin. All three are building more packaging space: SK hynix in Cheongju and Indiana, Samsung in Cheonan and Onyang, and Micron in Singapore.

HBM capacity limits accelerator output the same way CoWoS does. Chip-level detail is on HBM; the DRAM fabs behind it are on DRAM Fabs.

Inside a stack

An HBM Stack Is 12 or 16 Dies on a Logic Base

ONE HBM STACK (NOT TO SCALE) INTERPOSER BASE LOGIC DIE 12 or 16 DRAM dies core dies, thinned to tens of microns Through-silicon vias (TSVs) carry signals and power up the stack Microbumps between dies MR-MUF at SK hynix; TC-NCF at Samsung, Micron Base die TSMC 12nm-class (SK hynix); own 4nm (Samsung)

Each stack must pass known-good-stack test before shipping, because a bad stack found after CoWoS assembly scraps the accelerator and every other stack on it. Samsung and Micron bond dies with thermo-compression and non-conductive film (TC-NCF); SK hynix uses mass reflow with molded underfill (MR-MUF). Hybrid bonding, with no bumps between dies, is expected for taller stacks in later generations.

Intel's model

Intel Packages for Itself and for Foundry Customers

Intel has packaged its own processors since the 1970s, from Penang, Malaysia, its first overseas site in 1972, to its largest assembly and test plant in Ho Chi Minh City, Vietnam. Fab 9 in Rio Rancho, New Mexico, opened in January 2024 for Foveros, and Penang's new advanced packaging plant starts its first phase later in 2026. Both now take outside customers through Intel Foundry, which makes Intel both an IDM and a packaging supplier.

Where it sits

Korea Holds the HBM Back End

Memory packaging sits beside the memory fabs: HBM in Korea for SK hynix and Samsung, and in Taiwan and Singapore for Micron. Disruption in Korea would hit HBM supply the way disruption in Taiwan would hit CoWoS. Intel's back end is the most spread out, across Vietnam, Malaysia, China, Costa Rica and New Mexico. The concentration picture is on Bottleneck Atlas.

Flagship plants

Flagship IDM Packaging Plants

  • Made in US
  • US planned
  • Made abroad
IDM captive packaging plants
FacilityOperatorLocationOutputStatusUS status
Intel Fab 9 (Rio Rancho)IntelRio Rancho, New Mexico3D and 2.5D packaging for Intel and foundry customersOperationalMade in US
SK hynix West Lafayette (HBM packaging)SK HynixWest Lafayette, IndianaHBM advanced packagingConstructionUS planned
Intel Penang (Back - end/Packaging)IntelPenang, MalaysiaXeon, GPU die packagingOperational/ExpandingMade abroad
Micron Singapore HBM PackagingMicronSingapore, SingaporeHBM advanced packagingRampMade abroad
Samsung Cheonan PackagingSamsung MemoryCheonan, South KoreaHBM and advanced packagingOperationalMade abroad
Samsung Onyang HBM FabSamsung MemoryAsan, South KoreaHBM packagingConstructionMade abroad
SK Hynix Cheongju P&T7SK HynixCheongju, South KoreaHBM packagingPlannedMade abroad

Record

Dataset Record

Dataset
IDM packaging rows of the SemiconductorX fab dataset (fabs2026)
Sources
Counterpoint HBM share (September 2026); TrendForce Samsung and SK hynix packaging reports (August and September 2026); Evertiq; Singapore EDB; Intel newsroom (July 2026)
Last verified
October 2026