448G Copper Meets Optical: Luxshare-Tech’s Path to Hybrid Interconnects for AI Architectures

As AI computing systems continue to evolve toward higher density and larger scale, the connections between chips, boards, and computing nodes face increasingly complex requirements. Transmitting more data within a limited space requires a comprehensive consideration of signal loss, routing density, power consumption, and deployment costs.

At a recent seminar, Cheng Yun, Senior Product Manager for Copper Interconnects at Luxshare-Tech, delivered a presentation titled “Strengthening the Foundation of High-Speed Copper Interconnects to Support the Coordinated Development of Optical and Electrical Technologies.” He shared progress on 448G end-to-end interconnect solutions as well as interface innovations aimed at optical-copper synergy. This issue focuses on high-speed copper interconnects, exploring everything from signal paths to key components to further illustrate Luxshare-Tech’s understanding and practical approach to interconnect requirements for AI computing power.

Cheng Yun, Senior Product Manager for Copper Interconnects at Luxshare-Tech

The evolution of high-speed interconnects toward 224G and 448G places higher demands on link loss and crosstalk control. Where the signal is routed from, how far it travels on the PCB, and how many connection points it passes through all affect the final transmission performance.

Luxshare-Tech has developed a strategy centered on Near-Package Copper Interconnect (NPC), Co-Package Copper Interconnect (CPC), and Near-Package Optical Interconnect (NPO). By replacing some high-speed PCB traces with copper cables, signals are routed closer to the chip, reducing the on-board transmission path before connecting to the front-panel I/O or backplane interfaces. Along this path, different trade-offs must be made at various points. Space within nodes is compact, so thinner cables are typically prioritized to facilitate high-density routing; between nodes, the focus shifts to transmission distance, where thicker cables can reduce loss per unit length, and signal processing solutions are integrated to meet link requirements.

From cable cartridges and backplane connectors to CPC/NPC, high-speed I/O, and DAC, ACC, and AEC cables, Luxshare-Tech’s product portfolio covers applications within cabinets, within nodes, and between nodes. Customers can conduct selection and validation based on the complete link, reducing the need for repeated matching between different components.

Regarding Near-Package Optical Interconnect (NPO), Luxshare-Tech’s Copper Interconnect Business Unit focuses on providing NPO sockets to customers. Current solutions cover 112G and 224G, and preliminary research on 448G is underway; a variety of product forms flexibly support different customer needs.

Collaboratively Advancing 448G Innovation from Materials to Interfaces

This presentation highlighted progress on solutions such as Optamax™, KOOLIO™, Airchannel™, and Intrepid™ NEXUS. Behind these high-speed upgrades lies the step-by-step optimization of cable and interface designs, as well as manufacturing processes.

The Optamax™ twinax cable [CC1] [WW2] solution emphasizes low loss and low differential delay skew, offering various wire gauges, materials, and structural configurations. Samples and test data for 27, 30, and 31 AWG specifications were displayed on-site to serve as references for different space and transmission requirements.

The KOOLIO™ CPC solution uses an Optaflex™ interlayer to shorten the signal path, combining a “zero stubs” design with 360° full shielding to reduce signal reflections and crosstalk. For 448G applications, the solution builds upon the existing 224G design by optimizing the internal structure of the interface, as well as the cable and termination processes.

Airchannel™ and Intrepid™ NEXUS are advancing development to address chip-to-I/O and backplane connectivity requirements, respectively. The simulations and sample tests demonstrated at the event provided a basis for subsequent product optimization.

Termination positions of contacts and cables, as well as the injection molding process, all affect link performance. Therefore, verification must cover the entire link—comprising the connector, cable, and test board—and feed test results back into the design and manufacturing processes.

Balancing Density, Distance, and Maintenance Requirements for Real-World Deployment

In inter-node connections, extending transmission distances requires coordinated efforts across the chip, cable, termination process, and board design. During the seminar, Luxshare-Tech introduced new 1.6T OSFP AEC as well as 1.6T/2.4T OSFP DAC and ACC solutions.

Luxshare-Tech is driving the 1.6T AEC toward transmission targets of 6.5 meters or even 7 meters through the joint optimization of chip selection, twinax cable specifications, termination processes, and board design. Specific capabilities still require evaluation based on configuration and validation conditions.

Connecting the Evolution Path from Optical to Copper Through Open and Compatible Design

The development of optical interconnects also requires support from electrical connection interfaces. Taking NPO as an example, electrical signals still need to be transmitted between the chip and the optical engine; therefore, the signal performance, structure, and assembly methods of the socket are all critical components of the design solution.

Luxshare-Tech is simultaneously developing NPC solutions compatible with NPO sockets and packaging, enabling customers to evaluate different configurations of near-package optical and copper interconnects under corresponding interface conditions. NPO sockets are also available for standalone supply, allowing optical engine manufacturers and system customers to select components based on project requirements while maintaining flexibility in their supply chain mix.

The development of these solutions draws on Luxshare-Tech’s expertise in interface R&D, cable materials, precision molds, stamping and injection molding, and automated manufacturing. Particularly for high-density, high-speed products, automated assembly and process control are critical to maintaining product consistency and bridging the gap between prototype development and mass production.

At the system level, teams specializing in electrical interconnect, optical interconnect, thermal management, and power supply collaborate on solution design to provide customers with architectural references. Space, power consumption, and thermal management issues arising from changes in connection methods can be evaluated collectively during the early stages of development, enabling us to offer customers more professional and systematic solution recommendations.

Upgrading high-speed copper interconnects requires the joint optimization of cables, connectors, and manufacturing processes, followed by validation across the entire link. Luxshare-Tech combines 448G R&D, precision manufacturing, and compatibility design to help customers balance signal performance, deployment conditions, and maintenance requirements, ensuring that technological advancements are effectively implemented in system applications.

Key Takeaways

• Luxshare-Tech’s NPC, CPC, and NPO strategy shortens high-speed signal paths by routing copper cables closer to the chip, reducing PCB trace loss and enabling denser, more efficient 224G/448G interconnects for AI architectures.

• A full product portfolio, from Optamax™ twinax and KOOLIO™ CPC solutions to Airchannel™, Intrepid™ NEXUS, and OSFP AEC/DAC/ACC cables, covers intra-cabinet, inter-node, and hybrid optical-copper needs, supported by end-to-end link validation.

• Compatible designs that pair NPO sockets with NPC solutions, combined with cross-functional collaboration across electrical, optical, thermal, and power teams, give customers flexible architectures that balance signal performance, power, thermal constraints, and real-world deployment requirements.