The narrative around glass substrates is shifting from "who announces first" to "who can deliver on time." In the second half of 2026, several closely timed yet divergent developments have brought this shift into the spotlight: in late July, Intel and Lens Technology advanced their collaboration on glass substrate packaging for the AI era; on August 11, South Korean equipment manufacturer Avaco and its affiliate AVATEC launched a pilot line for TGV (Through Glass Via) process validation; and on August 12, supply chain sources reported that reliability evaluation of Samsung Electro-Mechanics' customer samples has hit a bottleneck, potentially delaying the production line construction plan for its joint venture GlaSSEM and pushing mass production to post-2028.
Within the same month, some companies signed agreements, some built production lines, and others were asked to re-validate. This is not contradictory. The glass substrate has moved beyond the stage of "material performance comparison" and entered the engineering validation phase centered on customer reliability certification. What determines the pace is no longer the theoretical advantages of glass over organic substrates, but whether the glass can withstand reliability evaluations such as thermal cycling and temperature-humidity testing after undergoing drilling, copper filling, routing, and component mounting, while continuously maintaining flatness, low warpage, and stable conductivity. Specific test items and thresholds vary by customer specifications, but this process cannot be compressed by capital expenditure or market hype, which is the fundamental reason for the recent adjustments in industry timelines.
01Samsung Electro-Mechanics' Delay Exposes More Than a Single Misstep
Samsung Electro-Mechanics' delay spans a nine-month timeline. Supply chain information leaked to the market shows that the company communicated its intention to procure equipment for the GlaSSEM production line to suppliers in November 2025, but the order placement was pushed from December 2025 to March 2026, and then to June, with no new milestones provided since. Although major suppliers for coating, etching, laser drilling, and inspection have been basically confirmed, the orders have not been finalized.
This does not mean the company is unwilling to invest. In early July, GlaSSEM signed a final agreement with Dongwoo Fine-Chem, a subsidiary of Japan's Sumitomo Chemical, with a registered capital of 482.1 billion KRW, in which Samsung Electro-Mechanics holds a 66% stake. The public goal of the joint venture is to be established in 2026 and set up a supply system in the second half of fiscal 2027; this is not the same concept as full-scale mass production. As for equipment delivery schedules, the specific line construction pace at the Pyeongtaek plant, and subsequent mass production timelines, these currently still depend on customer validation and equipment integration progress.
The real bottleneck lies in the samples. Existing supply chain information points to the reliability validation of customer samples; however, the company has not publicly disclosed specific test items, failure mechanisms, or customer identities. Readjusting the glass formulation and TGV drilling parameters, resubmitting samples, and completing the customer's full-process retest are widely understood in the industry as the subsequent path. The key to glass substrates is no longer just "whether micro-holes can be drilled," but whether the substrate can avoid cracking and maintain performance after the chip is mounted and subjected to heat.
Samsung is not an isolated case. The commercialization pace of SKC and its U.S. subsidiary Absolics is also being adjusted, with market expectations that it will complete final reliability testing within 2026 and advance to full-scale production in 2027. SKC has confirmed that its glass substrate business is preparing for customer reliability evaluation and plans to produce relevant samples and review projects under discussion with multiple customers; however, there has been no official disclosure from the company regarding the customer list, final certifications, or mass production orders. The industry's constraints have shifted from laboratory feasibility to stable yield rates and customer certifications, and the two must not be confused.
02The Repeatedly Revised Mass Production Calendar
The timelines currently provided by various parties are quite conservative. Absolics' latest schedule is to complete reliability testing in 2026 and advance to full-scale production in 2027, which is delayed compared to previous market expectations. Samsung Electro-Mechanics' GlaSSEM aims to establish a supply system in the second half of fiscal 2027, with the specific mass production time still uncertain. Dai Nippon Printing's TGV pilot line has been built, with the goal of establishing the system required for full-scale mass production in fiscal 2028. LG Innotek once set its mass production target for 2027-2028, but the subsequent commercialization pace still depends on technological and demand progress. TSMC (Taiwan Semiconductor Manufacturing Company) views 2026 as a critical window for CoPoS equipment and material validation, with varying judgments on subsequent trial and mass production timelines. Lens Technology has disclosed the construction of relevant pilot lines, sample trial production, and customer technical testing, but batch production still requires subsequent agreements and validation support.
Industry research institutions judge that TGV glass substrates may not enter the mainstream of Advanced Packaging until after 2030; it is currently still in early validation, expected to supplement rather than completely replace existing packaging solutions. Domestic institutions are relatively optimistic about the industrialization pace, viewing 2027-2028 as the first window for industrialization validation, and predicting that glass core substrates may see small-batch shipments starting in 2027, with accelerated volume growth in 2028. These are all institutional forecasts or estimates, not realized industry facts.
A delayed timeline does not mean disappearing demand. Public data shows that AI infrastructure and high-performance computing are driving up the demand intensity for high-end IC (Integrated Circuit) packaging substrates, and manufacturers are simultaneously expanding capacity. The demand growth for traditional substrates occurring concurrently with the delayed mass production of glass substrates indicates that the current greater challenge for glass substrates lies in the technological maturity on the supply side, rather than the existence of downstream demand. What the market needs is not just another "theoretically better" material, but a material system capable of stable delivery under conditions of large sizes, high layer counts, and high-frequency interconnections.
03Intel and Lens Technology
The collaboration between Intel and Lens Technology is worth dissecting. According to Lens Technology's announcement, the two parties signed a memorandum of understanding focusing on TGV Advanced Packaging: Lens Technology is responsible for through-hole formation in glass substrates, high-precision laser processing, metallized via deposition, and multi-layer interconnect routing; Intel intends to provide illustrative architecture information, Design for Manufacturability (DFM) guidelines, benchmarking, and validation methods. The focus of this division of labor is not on a single order, but on the spillover of the certification system. The willingness of the designer to provide DFM rules and validation methods means that the glass processor will enter the design closed-loop of the actual packaging architecture earlier.
This binding has its practical foundation. Lens Technology has disclosed the construction of relevant pilot lines, sample trial production, and sample submission to some potential customers, with some customers entering the technical testing phase after passing initial proof of concept. The market is also circulating reports of progress such as a pilot line with a monthly capacity of 3,000 panels, zero ppm non-through rate for millions of vias, minimum via diameters below 10 micrometers, a 30,000-square-meter TGV-dedicated factory building, and joint validation of 22-layer glass core substrates; until the company makes further disclosures on these data, they should not be equated with confirmed mass production facts.
However, a memorandum cannot be equated with an order. Lens Technology's announcement has clearly warned that there is uncertainty regarding whether a formal agreement will be signed subsequently, and as of the announcement date, the TGV business has not had a substantive impact on operating performance. For the industry, this is more like a strategic positioning of capabilities; financially, it is still a distance away from forming verifiable business increments.
04Japan Leads in Validation, Chinese Panel Makers Accelerate Entry
The advancement paths of Japanese and Chinese companies can supplement the understanding of the divergence in this round of mass production calendars. Shinko Electric showcased a 22-layer glass core substrate in July—stacking 11 layers of copper routing on each side of the glass. Its technical focus is not just on the number of layers, but on dispersing thermal stress by using protective materials at the edges of the substrate to suppress SeWaRe defects under thermal loads, which refer to internal cracks and delamination that may occur in glass during processing or thermal cycling. Dai Nippon Printing, on the other hand, launched a TGV glass core substrate pilot line in Saitama in December 2025, aiming to establish the system required for full-scale mass production in fiscal 2028. The commonality between the two companies is that their public actions fall on engineering links such as multi-layer routing, thermal stress control, and pilot validation, rather than simply announcing mass production.
Chinese companies have a different entry path. In August, industry research institutions listed 18 Chinese listed companies participating in the glass core substrate supply chain, covering special glass, TGV processing, metallization, and Advanced Packaging. BOE's public progress is more representative: its glass substrate packaging trial line achieved fully automated equipment line-through in the first half of 2026, with a designed capacity of 1,000 panels per month; the company has completed the development and submission of large-size, high-layer-count glass core substrate samples, and some domestic customers have entered the technical testing phase. It must be emphasized that this business has not yet reached mass production, nor has it generated mass production revenue.
Validation on the equipment side is also advancing simultaneously. The TGV pilot line launched by Avaco and AVATEC supports 515×510 mm large-size glass and connects processes such as laser drilling, etching, seed layer deposition, and optical inspection. Its significance does not lie in immediately forming scaled capacity, but in validating the repeatability and connection efficiency of large-size glass across multiple critical processes. The actions of Japanese material and substrate companies, Chinese panel makers, and South Korean equipment manufacturers ultimately point to the same thing: whoever can first organize glass processing capabilities into replicable semiconductor manufacturing capabilities will have the opportunity to navigate through the customer certification cycle.
05SCHOTT and Corning Push Glass Toward Optical Interconnects
The layout of material manufacturers shows that glass substrates do not have just the single value curve of "substituting ABF." SCHOTT has publicly introduced glass substrate and Advanced Packaging-related products, with application directions covering high-density TGV, advanced heterogeneous packaging, and high-performance interconnects. Its products emphasize different coefficients of thermal expansion, thicknesses, and electrical characteristics to meet the material needs of high-performance packaging.
Corning's direction is more representative. The "Glass Bridge" concept, which the market is paying attention to, applies TGV to the next-generation design of CPO (Co-Packaged Optics), extending glass from packaging substrates to optical interconnect substrates. Corning and NVIDIA have signed a multi-year commercial and technical collaboration, with the official disclosure focusing on expanding U.S. optical connectivity and fiber optic manufacturing capabilities; this collaboration itself should not be directly written as a glass substrate or Glass Bridge project. Previously, BOE and Corning signed a three-year memorandum of understanding covering glass substrate packaging substrates, optical interconnects, and other directions.
This layout changes the judgment on the first batch of applications. NVIDIA has publicly introduced the CPO technology direction, and Broadcom has called its second-generation Tomahawk 5-Bailly the industry's first mass-produced CPO solution. This indicates that the CPO ecosystem is entering a more specific engineering stage. Compared to the longer industrialization cycle of glass core substrates, glass optical interconnect substrates for CPO may form an earlier entry point for commercialization. Intel also positions glass as a foundational technology capable of providing both electrical and optical integration on the same platform.
However, material barriers should not be underestimated. Glass materials, TGV via formation, metal filling, low-loss routing, thermal expansion control, and large-size manufacturing all involve patents and process accumulation. After the industry matures, patent licensing and process route selection could become new competitive variables.
06Yield Rate Is the Only Hard Currency
Underlying all timeline debates is the same engineering problem: TGV yield rate. TGV is a process that uses lasers to drill tiny vertical vias in glass and fills them with copper to conduct electrical signals, requiring thousands of such vias to be precisely aligned in brittle materials per substrate. The current yield rate for glass core packaging is about 60% to 70%, far below the 80% to 90% for organic ABF substrates.
The brittleness of glass means that microscopic cracks during laser drilling can lead to the scrapping of the entire substrate, making costs 30% to 50% higher than ABF. MarketsandMarkets predicts the global glass substrate market will reach $8.4 billion in 2028, while Sigmaintell provides a close figure of $8.5 billion, potentially reaching $27.6 billion by 2030—but the premise of these numbers is that yield rate and certification issues achieve substantive breakthroughs within the next two years.
This round of intensive dynamics in the summer of 2026 is essentially the first major test for glass substrates moving from the laboratory to the factory. The exam is not over yet, but the passing line has already been drawn.