OKI Develops 124-Layer PCB Technology

OKI Circuit Technology has developed a 124-layer printed circuit board (PCB) for wafer inspection equipment used with next-generation high-bandwidth memory (HBM) on AI semiconductors, a roughly 15% layer increase over prior 108-layer designs while keeping board thickness at 7.6 mm. The higher layer count was enabled by ultra-thin materials, new tooling and handling techniques for those materials, and a proprietary automatic transport system for ultra-thin sheets. OKI aims to qualify mass-production processes by October 2025 at its Joetsu Plant, and will showcase the technology at PCB East 2025 in Massachusetts.

The technical push responds to rising demands for extremely high-speed, high-frequency, dense data transfer between GPUs and stacked DRAM memory as AI workloads and chip miniaturization increase signal counts and wafer-mounted chip density. Conventional multilayer limits were driven by thickness constraints; the new approach maintains the same thickness while increasing layer density to meet inspection-equipment performance and quality needs. The development fits within OKI’s electronics manufacturing services strategy - spanning design, production and reliability testing - and targets growth sectors such as AI semiconductors, aerospace, defense, robotics, and next-generation communications.