OKI Advances Ultra‑High‑Layer PCB Technologies for Next‑Generation Semiconductor and Aerospace Test Platforms

OKI Circuit Technology has developed new design and production capabilities for 180‑layer, 15 mm‑thick printed circuit boards intended for advanced semiconductor testing systems. While the primary application targets wafer‑level testing for high bandwidth memory used in AI processors, the underlying technologies carry direct relevance for aerospace programs that depend on high density, high reliability electronic architectures. The achievement marks a significant increase in both layer count and board thickness compared to the company’s previous 124‑layer, 7.6 mm configuration.

Meeting the Demands of High‑Speed, High‑Density Signal Environments

Next‑generation AI semiconductors generate extremely large volumes of high‑speed signals, a trend mirrored in aerospace systems that increasingly rely on dense sensor arrays, onboard data fusion, and advanced computing payloads. As signal counts rise and pitch dimensions shrink, test hardware must support higher layer densities without compromising impedance control, power integrity, or drilling accuracy. Historically, these constraints limited practical PCB thickness and layer counts, restricting the ability to scale toward future high‑frequency and high‑bandwidth requirements.

New Technologies Enable 180‑Layer, 15 mm‑Thick PCB Structures

To overcome these limitations, OKI developed two complementary technologies. The first is a conductive Sintering Paste for Via Bonding that allows multiple multilayer boards to be stacked and electrically connected through bonded vias. The second is an ultra‑high‑thickness PCB manufacturing process capable of producing structures up to 15 mm thick. By combining these approaches, OKI created a 180‑layer architecture formed by stacking and interconnecting three 60‑layer boards.

This modular approach allows each multilayer section to maintain stable impedance characteristics, signal quality, and power delivery performance using established fabrication methods. When stacked, the resulting structure achieves both extreme layer counts and the electrical performance required for high‑speed, high‑frequency, and high‑density data transfer. These attributes align closely with the needs of aerospace test systems, avionics qualification platforms, and emerging spaceborne computing architectures.

Positioning for Growth Across AI, Aerospace, and Next‑Generation Communications

OKI developed these technologies with an eye toward markets experiencing rapid expansion, including AI semiconductors, AI servers, aerospace and defense electronics, and advanced communications systems. As aerospace programs adopt more computationally intensive payloads and require increasingly complex test and validation hardware, ultra‑high‑layer PCBs are expected to play a growing role in ensuring performance and reliability.

The company is preparing its Joetsu Plant for mass production, targeting initial shipments in October 2026. The facility has long supported high multilayer, high precision, large format PCB manufacturing for semiconductor test equipment, positioning it well for the transition to thicker and more complex board structures.

Showcasing the Technology at PCB East 2026

OKI will present these developments at PCB East 2026 in Worcester, Massachusetts, where attendees will be able to review the new stacking and bonding technologies and discuss potential applications across semiconductor, aerospace, and communications sectors.