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OKI Develops High-Accuracy Simulation Technology for High-Frequency Vias for 1.6 Tbps-class High-Speed Transmission PCBs to Support Next-Generation AI Data Centers

via Business Wire

- Achieving high accuracy control of via characteristics, critical for multilayer PCBs with increasingly higher frequencies, and shortening development times, using simulation-based design that accounts for in-house manufacturing processes -

The OKI Group’s PCB business company OKI Circuit Technology (OTC; President: Masaya Suzuki, Head office: Tsuruoka City, Yamagata) has successfully developed High-Accuracy Simulation Technology for High-Frequency Vias that enables precise control of via (Note 1) characteristics in 1.6 Tbps-class high-speed transmission PCBs that support next-generation AI data centers. By leveraging this new technology, OKI will contribute to shortening development and mass production startup times for customers’ high-transmission PCBs through precision control of via characteristics, critical for multilayer PCBs with increasingly higher frequencies and higher densities.

Against the backdrop of the rapid advances and proliferation of generative AI systems, AI servers, data centers, and AI semiconductors are becoming increasingly larger in capacity and faster. The PCBs mounted in related equipment have become increasingly multilayered and structurally complex (Note 2), and measures to reduce transmission losses and signal reflections that impede high-speed transmission have become increasingly important. This is especially true for the vias—the structural transition points that affect the high-frequency signals used for high-speed transmission—used to electrically connect the layers within a multilayer PCB, making control of via characteristic impedance (Note 3), which minimizes signal reflection, a key element technology.

For these reasons, highly accurate via models have become indispensable for SI simulation (Note 4) for verifying final signal quality at the design stage in PCB development for high-frequency applications. However, in high-frequency bands in which the fundamental frequency (Note 5) exceeds 50 GHz, conventional modeling methods (Note 6) struggle to accurately represent the effects of the manufacturing process and variations and material properties (Note 7) in high-frequency regions. This makes it difficult to obtain simulation results that correlate with actual characteristics (measured results), posing a major issue.

To address this issue, OTC has successfully developed High-Accuracy Simulation Technology for High-Frequency Vias, which accounts for the increasingly complex characteristics of high-frequency vias. Specifically, prior to PCB fabrication, the simulation results of the new technology are used to comprehensively evaluate and optimize the via structure, dimensions, and manufacturing margins, in accordance with our factories’ manufacturing lines, to extract the optimal conditions meeting the signal quality requirements. OTC drew on its years of accumulated evaluation data to build its own database of parameters such as finished dimensions, manufacturing variations, and material properties. The technology enables highly accurate via modeling using 3D electromagnetic field analysis tools and ensures reliable signal characteristics in actual products.

OTC is to exhibit at the OTC booth (No. 512) at SWTest Asia 2025, Asia’s only conference dedicated to semiconductor wafers, to be held at Hilton Fukuoka Sea Hawk from November 20 to 22, 2025.

[Terminology]

Note 1: Via (via hole)

Hole that electrically connects the layers within a multilayer PCB

Note 2: Increasingly complex via structures

In addition to conventional through vias that connect the front and back sides of PCBs manufactured by a single stacking process, a variety of structures have emerged, such as non-through vias, which connect only part of the inner layers from the surface, and build-up vias, formed by stacking individual layers one by one.

Note 3: Impedance

Ratio of voltage to current in an AC circuit, representing the degree to which current flow in an AC circuit is impeded: the greater the impedance, the smaller the current; the smaller the impedance, the larger the current

Note 4: SI simulation

Signal Integrity: Simulation to ensure signal quality.

Note 5: Fundamental frequency

A digital signal is composed of a number of harmonics, which are frequency components at odd integer multiples of a fundamental frequency, superimposed on each other.

Note 6: Conventional modeling methods

Parameters such as relative permittivity and dielectric loss tangent that express physical dimensions and electrical characteristics are expressed using nominal values published by material manufacturers.

Note 7: Material properties

Parameters representing the electrical properties of PCB substrate, copper foil, etc., in the simulation. Relative permittivity and dielectric loss tangent of substrate, surface roughness of conductor, etc.

[Related link]

High-speed Transmission introduction site: https://www.oki-otc.jp/en/solution/kousoku.html#via-sim

About Oki Electric Industry (OKI)

Founded in 1881, OKI is Japan's leading information and telecommunication manufacturer. Headquartered in Tokyo, Japan, OKI provides top-quality products, technologies, and solutions to customers through its Public Solutions, Enterprise Solutions, Component Products, and Electronics Manufacturing Services businesses. Its various business divisions function synergistically to bring to market exciting new products and technologies that meet a wide range of customer needs in various sectors. Visit OKI's global website at https://www.oki.com/global/.

Notes:

  • Oki Electric Industry Co., Ltd. is referred to as "OKI" in this document.
  • Oki Circuit Technology Co., Ltd. is commonly referred to as OKI Circuit Technology.
  • The names of the companies and products mentioned in this document are the trademarks or registered trademarks of the respective companies and organizations.

 

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