Major Breakthrough in AI Chip Packaging: Japanese Firm Shinko Electric Develops '22-Layer Glass Substrate'

Japanese semiconductor packaging substrate manufacturer Shinko Electric Industries has achieved a significant breakthrough in glass substrate technology, successfully constructing a 22-layer copper wiring structure—11 layers stacked on each side of the glass substrate—demonstrating a key advancement toward high-layer-count, high-density packaging.

Glass substrates have long been considered a crucial direction for advanced semiconductor packaging, but practical applications have been limited by the 'SeWaRe' issue—cracks or delamination within the glass.

While glass offers excellent flatness and a low coefficient of thermal expansion, the material is inherently brittle and prone to micro-cracks during processing and thermal cycling, negatively impacting yield and reliability.

Shinko Electric has overcome this bottleneck through material innovation, applying a polymer-based protective material to the edges of the glass substrate to disperse stress concentrated in specific areas during thermal loading. This effectively suppresses SeWaRe even after thermal stress.

In addition to resolving cracking and delamination issues, Shinko Electric has also advanced through-glass via (TGV) processes—creating fine holes that penetrate the glass substrate—and multi-layer stacking technology for insulation and copper wiring layers.

The successful creation of a 22-layer structure indicates that glass substrates now possess wiring capabilities comparable to current high-end organic substrates, with advantages in dimensional stability and warpage resistance.

Founded in 1946, Shinko Electric entered the semiconductor packaging field in 1959 based on glass-to-metal sealing technology and is currently a key supplier to major chipmakers such as Intel and AMD.

In 2023, Fujitsu sold Shinko Electric to a consortium led by Japan Investment Corporation (JIC), supported by the Japanese government, including Dainippon Printing (DNP) and Mitsui Chemicals.

As AI chips increasingly adopt multi-die integration, packaging sizes continue to grow, making thermal warpage issues in traditional organic substrates more pronounced. This has made glass substrates—due to their high rigidity and low thermal deformation—emerging as a key technological option for large AI chip packaging.

Multiple companies are now accelerating investments in glass substrates. Samsung has established a joint venture, 'GlaSSEM,' with Dongwoo Fine-Chem to advance related business; Intel announced in early 2026 that it had overcome the 'No SeWaRe' challenge, while TSMC has unveiled its CoWoS glass substrate development plan, indicating intensifying technological competition.

The industry widely views 2026 as the commercialization year for glass substrates. Market estimates project the global packaging glass substrate market to reach $18.6 billion by 2026.

Shinko Electric's successful development of a 22-layer glass substrate not only validates the technical feasibility of high-layer stacking but also further drives the transition of glass substrates from R&D to mass production.