Industry roadmaps show glass-core substrates are entering final qualification, though commercial adoption remains delayed.

Glass-core substrates, positioned as the replacement for organic chip packaging that Intel announced in September 2023 with more than $1 billion in backing, are now in final qualification. Despite this progress, the technology has yet to appear in any commercial product. On its July 27 earnings call, SKC—a material manufacturer and chemical affiliate of the SK Group—stated that embedded glass substrate samples from its Absolics plant in Covington, Georgia, are undergoing package-level reliability evaluation in Taiwan, with results expected before year-end. Every timeline in the segment has slipped predictably. Absolics originally targeted mass production for the first half of 2024, and previously reported claims that AMD would adopt glass substrates for CPUs between 2025 and 2026 have passed unfulfilled.

The technical case for glass-core substrates relies heavily on figures Intel published previously, including 10 times the interconnect density of organic substrates and a 50% reduction in pattern distortion. Glass cores can be tuned to a thermal expansion coefficient of roughly 3 to 10 ppm per degree Celsius against silicon’s 2.6 ppm, cutting warpage by approximately half compared with organic cores. Additionally, rectangular panels in the emerging 510mm x 515mm format utilize more than 75% of their area for large dies, versus roughly 50% for round 300mm wafers. Through-glass vias have been demonstrated at six microns in diameter with aspect ratios beyond 15:1 at ECTC 2025, and Georgia Tech has shown stacked glass operating at 220 GHz with 0.3 dB of loss. However, glass chips and cracks at the edges during drilling and dicing. MIT Technology Review reported in March that early Absolics production runs broke hundreds of panels every couple of days during initial testing. While edge-coating work has reduced measured edge stress from 95 MPa to 49 MPa, and low-temperature dielectrics curing below 180°C have been developed to mitigate thermal stress during build-up, metallizing vias below 10 microns and maintaining nanometer-scale flatness across half-meter panels remain unresolved manufacturing challenges.

Intel demonstrated a working system booting Windows on a glass-core substrate in early 2025. Rahul Manepalli, Intel’s VP of module engineering, told MIT Technology Review that the benefits of glass cores are “undeniable” and that the company wants “to be one of the first ones who do it.” Intel’s commercial strategy has evolved accordingly. Rather than direct deployment, Intel has shifted toward licensing its patents and showcasing demo vehicles, with its own commercial rollout now projected for around 2030. At NEPCON Japan in January, Intel Foundry unveiled its first thick-core glass substrate featuring two EMIB bridge dies embedded directly in the glass: a 78mm x 77mm package with two 800-micron-class glass layers, 10 redistribution layers on each side, and approximately 1,716 mm² of silicon on top—roughly two full reticles—with no micro-cracking reported in testing. Intel is also developing co-packaged optics prototypes built on glass at its Rio Rancho, New Mexico facility. Packaging partner Amkor placed commercialization within three years during an industry event in Seoul in April, though TrendForce currently situates Intel’s broader commercialization around 2030. Separately, DigiTimes reported in late July that Intel is in early-stage discussions with Chinese cover-glass manufacturer Lens Technology regarding a packaging partnership, though no formal agreement has been reached.

Samsung Electro-Mechanics formalized a 482.1 billion won ($310 million) joint venture with Sumitomo Chemical’s Dongwoo Fine-Chem on July 2. Named GLASEM, the venture allocates 66% ownership to Samsung Electro-Mechanics and 34% to Dongwoo Fine-Chem, with production based in Pyeongtaek. It targets an operating plant in the second half of 2027, producing drilled and metallized glass cores for Samsung’s substrate lines. Samsung moved its glass program from advanced R&D into a business-execution unit in February and has been sampling from a pilot line at its Sejong plant since late 2024. Korean industry reports indicate samples have been sent to AMD and Broadcom, while rating Samsung’s overall glass maturity at 40 out of 100—a notable gap between marketing timelines and process readiness. Meanwhile, LG Innotek operates a third Korean initiative from its Gumi plant, having delivered prototypes in 2024 and targeting production between 2027 and 2028.

TSMC’s CoPoS line in Chiayi, constructed around 310mm x 310mm rectangular panels, received equipment in February, completed its pilot line around June, and aims for pilot production in 2027 with mass production slated for the second half of 2028. Equipment supplier SCHMID has characterized glass integration within this platform as “under review, not committed,” and TrendForce projects TSMC’s commercial-scale glass-core production post-2030. This suggests the industry’s largest packaging operation will prioritize panel-level solutions first, adopting glass later if at all. TSMC revived glass substrate research a couple of years ago after previously deprioritizing it, reportedly under pressure from Nvidia, whose accelerator packages are rapidly outgrowing current packaging capabilities. In Japan, Dai Nippon Printing began phased operations of a TGV glass-core pilot line at its Kuki plant in Saitama in December 2025 on 510mm x 515mm panels, with sample shipments expected from early 2026 and full mass production targeted for fiscal 2028. Toppan’s pilot line for glass cores and interposers at its Ishikawa plant was scheduled for commissioning in July. Nippon Electric Glass has scaled its ceramic-reinforced GC Core panel to 515mm x 510mm at 1mm thickness. Rapidus is evaluating panel-level packaging on 600mm x 600mm glass as part of its 2nm program, with viability assessed for the late 2020s. China’s entry is led by display manufacturer BOE, which is currently sampling from its pilot line.

The push for glass substrates is driven by escalating package sizes and interposer costs. TrendForce estimates Nvidia’s Rubin Ultra package at roughly 7,470 mm²—approximately nine reticles’ worth of silicon and memory—compared to around 2,739 mm² for Blackwell. CoWoS interposer wafers cost on the order of $10,000 each, comparable to a processed 7nm wafer. At these scales, organic substrates warp and lose dimensional stability, while round interposer wafers waste an increasing share of their area—precisely the inefficiencies glass panels aim to resolve. SEMI’s inaugural dedicated market report on glass cores, published in May alongside Global Net, projects initial production around 2028 for select high-performance applications and forecasts a 67.2% compound annual growth rate from 2028 to 2040. Yole places the advanced IC substrate market at $31 billion by 2030, with glass cores identified as key growth drivers.

Currently, no production design exists, and all customers attached to the technology—including AMD, Broadcom, AWS, and Nvidia—are cited solely from broader industry reporting. Nothing has been officially confirmed. Assessing near-term progress will require Absolics to publish solid package-level reliability results by year-end, or for any Korean manufacturer to announce its first officially named customer. Additionally, industry observers await clarification from TSMC regarding whether glass cores will be integrated into CoPoS architectures or remain under review well into the 2030s.