In August 2024, a seemingly ordinary personnel change caused a stir in the semiconductor industry. Dr. Gang Duan, a longtime Intel chip packaging expert, quietly departed after 17 and a half years to join Samsung Electro-Mechanics as Executive Vice President of America.

This technologist, named the 2024 Inventor of the Year, was a key driver of Intel's glass substrate technology. In an Intel promotional video, Duan proudly stated, "We believe that future AI systems will be built on ultra-large glass substrates." Today, those words have become the end of an era.

The departure of this renowned figure symbolizes a reshuffling of the glass substrate technology landscape. Amidst the exploding demand for AI chips, this field is undergoing a dramatic transformation.

The long journey from ceramics to glass

As a chip giant, Intel has always been ahead of the curve in substrate exploration.

As early as the 1990s, Intel led the industry's transition from ceramic to organic packaging, pioneering halogen and lead-free packaging and inventing advanced embedded chip packaging technology. During this process, the ABF (Ajinomoto Build-up Film) substrate technology, developed in collaboration with Japan's Ajinomoto Co., Ltd., marked a significant milestone in semiconductor packaging.

Due to its excellent electrical performance and mature manufacturing process, ABF substrates have quickly become the mainstream choice for high-end chip packaging. This organic substrate has not only supported the development of multiple generations of Intel processors but also laid the foundation for packaging technology for the entire industry.

However, as the performance requirements of AI chips continue to rise, the limitations of ABF substrates are becoming increasingly apparent. Traditional organic substrates are beginning to struggle with the increasing size and complexity of AI chips.

The advantages of glass substrates are clear. Compared to traditional plastic substrates, glass substrates offer a smoother surface, better thermal stability, and lower dielectric loss. It's reported that the spacing between glass core vias can be less than 100 microns, directly increasing the interconnect density between chips by a factor of 10. For AI chips that need to process massive amounts of data, this performance boost is undoubtedly revolutionary.

In September 2023, Intel announced the industry's first glass substrates for next-generation advanced packaging, with a planned launch between 2026 and 2030. This news shocked the industry and instilled a sense of urgency among competitors.

In an October 2023 conversation with SemiWiki, Dr. Raoul Mannepoli, Intel Fellow and Senior Director of Module Engineering in the Substrate Packaging Technology Development Organization, noted that Intel has been researching glass substrates for over a decade. Initially, the research began in collaboration with universities, while Intel's internal component and research teams also worked diligently to overcome challenges in their pursuit of making glass-based packaging a reality. After achieving key breakthroughs over the three and a half years from 2021 to 2023, the team entered an exploratory phase, integrating resources to develop a production line capable of scalable R&D.

The greatest challenge during this process was the fragility of glass. Initially, delivering a single panel intact from the start of the production line to the end required considerable effort. Even contact between the panel's edge and any metal surface could cause cracks or damage. Furthermore, architectural innovation presented numerous challenges, such as managing the stress of glass-based packaging and achieving optimal value in terms of interconnect density.

To address these issues, the Intel team innovated in tool design, researching how to handle this fragile material on the production line and how to add interconnect layers without stress. To date, Intel has over 600 inventions related to making glass suitable for packaging. These innovations enable the team to handle the fragile glass, build the interconnect layers, and ensure reliability.

Mannepoli emphasized that the design flexibility offered by glass substrates will undoubtedly trigger a significant amount of innovation, particularly in areas such as high-speed input and output signal transmission, improved power transmission, and optical integration, providing designers with broad scope for innovation. Currently, AI and data center workloads are already utilizing glass substrates, and once the infrastructure is established, high-density interconnect computing platforms, both client and data center, will continue to adopt glass substrates.

He stated that Intel is working to combine existing industry redistribution layer technology with glass-specific substrate processing techniques to initially narrow the cost gap. As production volumes increase and infrastructure matures, the cost of glass substrates is expected to eventually reach parity with organic substrates.

For Intel, the debut of the glass substrate in 2023 means that its technological layout over more than ten years has begun to bear fruit. In a press release, it optimistically stated that it will officially launch this revolutionary substrate technology later this decade.

Intel's strategic shift

As the glass substrate market becomes increasingly vibrant and the industry chain accelerates its formation, Intel is quietly re-evaluating its technology layout and resource allocation.

At the Intel Foundry Direct Connect 2025 conference held in late April, Naga Chandrasekaran, Intel's Executive Vice President and General Manager of the Foundry Technology and Manufacturing Group, explicitly stated that glass substrates will remain a key component of future advanced packaging systems.

He emphasized that, compared to advanced wafer manufacturing itself, advanced packaging capabilities are the core competitive differentiation tool for Intel's foundry business. He also revealed that Intel is currently developing ultra-large 120x120mm packaging technology and plans to launch glass substrate solutions with higher thermal stability in the next few years to support the packaging needs of the next generation of high-performance AI and HPC chips.

However, as Intel CEO Lip-Mo Tan has implemented a series of strategic contraction and refocusing decisions since taking office, internal investment in glass substrates has shown a clear weakening trend. Prioritizing resources for Intel's core product lines—including the 14A and 18A process nodes, Xeon CPUs, AI accelerator chips, and capacity development for its foundry business—is intended to put Intel back on a path of sustainable growth through improved financial discipline and execution efficiency.

This trend suggests that while Intel continues to emphasize glass substrates in technical rhetoric, its actual actions have shifted more towards "strategic outsourcing."

Analysts point out that even if glass substrates become an essential packaging material for high-density AI systems in the future, Intel can still choose to purchase off-the-shelf products from specialized suppliers, rather than continuing to bear the high investment and long-term risks of in-house development. In contrast, outsourcing can help Intel shorten development cycles, optimize its cost structure, and maintain procurement flexibility.

This shift from in-house development to outsourcing reflects Intel's pragmatic trade-offs in the face of intense market competition and financial pressure. Just as the company's current focus on advanced process nodes like 14A and 18A demonstrates its strategic convergence, the abandonment of in-house investment in glass substrates is seen as part of its overall tightening of capital expenditures and improving the profitability of its core businesses. By focusing its efforts on key areas where commercial breakthroughs are possible, Intel hopes to gain a more advantageous position in the trinity of chip manufacturing, foundry manufacturing, and system packaging.

Interestingly, while Intel increasingly favors outsourcing rather than building its own production lines, other manufacturers are quietly accelerating their glass substrate production.

Samsung's fast follow-up

First up is Samsung, which poached Intel chip packaging expert Duan Gang and has been planning glass substrates for a long time.

At CES 2024 in January 2024, Samsung Electro-Mechanics announced plans to establish a glass substrate pilot production line that year, with the goal of producing pilot products in 2025 and achieving mass production in 2026. Samsung Electro-Mechanics subsequently moved up equipment procurement and installation to September and will launch the pilot production line in the fourth quarter, a quarter ahead of schedule. It expects to begin producing glass substrates for high-end system-in-package (SiP) applications in 2026.

South Korean media reports indicate that Samsung Electro-Mechanics' glass substrate production line is designed to streamline production processes and adhere to Samsung's strict safety and automation standards. Equipment suppliers have been confirmed, with Philoptics, Chemtronics, Joongwoo M-Tech, and Germany's LPKF providing components.

In June of this year, Samsung Electro-Mechanics announced that preparations for a glass substrate prototype production line were nearing completion, with plans to begin supplying samples to two to three major US technology companies in 2025. Furthermore, the subsidiary is deepening its strategic collaboration with Samsung Electronics, particularly in areas related to the development of a glass interposer supply chain.

In its Q1 2025 earnings call, Samsung Electro-Mechanics stated that its AI accelerator glass substrate business will generate significant revenue starting in the second quarter, with sales expected to gradually increase as the application scope expands. Samsung Electro-Mechanics stated that despite uncertainty surrounding US tariffs, it believes the impact will be limited due to its relatively low direct exports of multilayer ceramic capacitors (MLCCs) and camera modules to the US market.

Samsung Electro-Mechanics' glass substrate production line, located in Sejong, South Korea, is expected to begin operations in the second quarter of 2025. Samsung Electro-Mechanics aims to leverage this capacity to support the growing demand for advanced packaging solutions for AI accelerators and other high-performance computing applications.

Samsung Electronics, on the other hand, is taking a more cautious approach. It has been revealed that Samsung Electronics has confirmed plans to introduce glass substrates into advanced semiconductor packaging by 2028. The key is to replace silicon interposers with glass interposers. This marks the first time Samsung Electronics' glass substrate roadmap has been confirmed.

A source familiar with the matter stated, "Samsung Electronics has developed a plan to transition from silicon interposers to glass interposers by 2028 to meet customer demand."

Interposers, also known as intermediate substrates, are a crucial component of AI chips. AI semiconductors utilize a 2.5D packaging structure, placing the graphics processing unit (GPU) at the center and high-bandwidth memory (HBM) around it. The interposer serves as a connection between the GPU and HBM.

Currently, interposers are made of silicon. Their advantages include high data transmission speeds and high thermal conductivity. However, due to the high cost of the material and processing, manufacturing costs are high. Glass interposers are emerging as an alternative. They facilitate the implementation of ultra-fine circuits, further improving semiconductor performance and reducing production costs.

While the industry is currently experimenting with replacing interposers and motherboards with glass, the transition to glass for interposers is expected to be faster than for motherboards. For example, AMD is pursuing a plan to incorporate glass interposers in its semiconductors by 2028.

Samsung Electronics' introduction of a glass interposer is being interpreted as a response to the growing demand for advanced semiconductors driven by AI. Since the company engages in the foundry business, manufacturing semiconductors to customer orders, its strategy is to prepare for and deliver next-generation technologies. It may also be used in Samsung's own system semiconductors and high-bandwidth memory (HBM) production.

Samsung Electronics is confirmed to be in discussions with supply chain companies about using glass interposers, rather than glass substrates, in "units" customized to chip size. Typically, glass substrates are produced in raw sizes of 510 x 515 mm and then cut to fit the chip. Intel, Absolix, and other companies are producing prototypes in this manner.

Samsung Electronics is reportedly choosing to perform this process on glass sheets smaller than 100 x 100 mm. Industry insiders analyze this as a "strategy to accelerate technology implementation and prototype production" and "to achieve rapid market entry." However, due to its small size, productivity may be lower in actual mass production.

Samsung Electronics has also developed a plan to package semiconductors at its Cheonan Complex using glass interposers provided by outsourced companies. This plan will utilize its established panel-level packaging (PLP) production line. PLP is a packaging method that uses square panels instead of wafer-level packaging (WLP), which involves packaging on round wafers. It is considered a process with high productivity and suitable for glass substrates.

Samsung Electronics is expected to strengthen its "AI Integrated Solutions" strategy by leading the glass interposer market. At last year's Samsung Foundry Forum, the company announced a one-stop AI solution encompassing foundry, HBM, and advanced packaging as its future strategy. The addition of glass substrates is expected to further enhance the competitiveness of its foundry and packaging operations.

Notably, Samsung's strategy differs significantly from Intel's. Leveraging the strengths of its group operations, Samsung Electronics began joint research and development of glass substrates with major electronics affiliates such as Samsung Electro-Mechanics and Samsung Display in March of this year. Samsung Electro-Mechanics will contribute its expertise in semiconductor-substrate bonding, while Samsung Display will contribute its glass technology. This marks the first time Samsung Electronics has collaborated with an electronics component company within the group on glass substrate research.

With Duan Gang joining the company, Samsung's strength in the glass substrate field has undoubtedly been further strengthened.

An industry landscape where many players are emerging

Besides these two giants, there are many more players in the glass substrate market.

First is TSMC. Although TSMC has not publicly stated specific plans regarding glass substrate technology, given its extensive experience in packaging, it likely already has relevant technical expertise. According to media reports, industry rumors are circulating that TSMC has restarted glass substrate research and development to meet Nvidia's future demand for FOPLP.

Furthermore, Taiwanese semiconductor equipment manufacturers are also making early preparations. Titanium Technology, a long-standing partner with Intel, has established the E-core System Alliance, a glass substrate supplier alliance that brings together laser and plasma equipment suppliers, testing companies, and material and key component manufacturers. 

The alliance is committed to collaborating and creating a complete glass substrate supply chain. The alliance has publicly displayed a 515×510mm glass core sample, incorporating key technologies such as laser processing, wet etching, and seed layer sputtering, with the goal of attracting orders from Intel and TSMC.

It is understood that the technical solutions provided by E&R not only cover equipment but also include mature mass production capabilities for FOPLP (Fan-Out Panel Level Packaging) on large-size substrates (300-700mm). These include processes such as laser marking, post-drilling plasma cleaning, ABF drilling, and post-debonding, as well as the ability to handle high warpage (up to 16mm). This form of industry chain alliance may play a significant role in the industrialization of glass substrates.

Other Korean manufacturers are also quietly making their moves.

SKC, a subsidiary of SK Group, showcased its glass substrates for AI data centers at CES 2025 through its subsidiary Absolics, highlighting their advantages, including support for ultra-fine circuits, multi-component integration (such as MLCCs), 50% thinner packaging thickness, 40% faster data processing speeds, and significantly reduced power consumption.

Absolics' first mass production facility in Covington, Georgia, has entered the prototype production phase, with an annual production capacity of approximately 12,000 square meters. The company aims to complete mass production preparations by the end of the year and is in supply negotiations with AMD, AWS, and others, nearing the pre-certification stage. Furthermore, the US Department of Commerce plans to provide $75 million in funding under the CHIPS Act to support Absolics' construction of a new facility. The facility is expected to create hundreds of jobs and boost the domestic supply of glass substrate materials.

LG Innotek, a subsidiary of LG Group, is actively expanding its semiconductor substrate capabilities and has stated that it is investigating glass substrates as a future mainstream packaging material and evaluating their potential for use in advanced packaging.

LG Innotek reportedly plans to produce glass substrate samples and enter the verification phase by the end of 2025, signaling an accelerated investment in the practical development of this new material. As a downstream packaging company, LG Innotek is also rapidly advancing its FC‑BGA (Flip Chip Ball Grid Array) technology, aiming to expand this business to $700 million by 2030.

In addition, another Korean company, JNTC, completed and announced the opening of South Korea's first dedicated semiconductor glass substrate plant in May 2025, with a monthly production capacity of 10,000 wafers and plans to begin mass production in the second half of the year. JNTC has reportedly signed NDAs with 16 global customers, entering the custom sample supply phase. JNTC also plans to build a large-scale production line in Vietnam to meet growing global demand. This is expected to triple production capacity and become a global growth engine for its glass substrate business.

Japan's Ibiden, one of the world's largest semiconductor substrate manufacturers, is also actively pursuing R&D in the glass substrate field, seeking to introduce it into the packaging substrate market. Its 2023–2027 capital expenditure plan explicitly includes "glass core substrate" R&D, indicating that it views glass substrates as a key growth area.

Reports indicate that Ibiden is increasing its IC substrate production capacity to support Nvidia's supply chain needs for the AI server market, and that future opportunities for mass production of glass substrates are brewing. If Ibiden successfully commercializes glass substrates, its position in the global packaging materials supply chain will be further consolidated, potentially leading Japan to focus on developing high-value-added packaging markets.

For manufacturers accelerating the development of glass substrate technology, achieving large-scale mass production before 2030 is not a luxury.

Redefining the industrial landscape

The departure of Intel's key glass substrate driver is more than just a talent turnover; it signals a reshuffle in the entire glass substrate industry.

Intel has shifted from a technology pioneer to a strategic sourcing role, Samsung is rapidly advancing with its group advantages, TSMC is quietly preparing its strategy, and numerous suppliers are fiercely competing across the supply chain. This diverse competitive landscape may be the catalyst needed for the rapid development of glass substrate technology.

For the AI chip industry, the maturity of glass substrate technology means greater computing power, lower power consumption, and smaller size. For the entire semiconductor packaging industry, the widespread adoption of glass substrates could usher in a new round of technological revolution and industry reshuffle.

In this glass substrate competition, there are no permanent leaders or laggards. Just as Duan Gang's move from Intel to Samsung demonstrates, the trajectory of technological development is often full of uncertainty. The only certainty is that, driven by the AI era, the industrialization of glass substrate technology is accelerating, and this transformation has only just begun.

Source: Semiconductor Industry Observer

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