NVMe Storage PCB Applications and Manufacturing Requirements for AI Servers

AI training, inference, and large-scale data processing involve frequent read and write operations for models, datasets, and intermediate data, placing high demands on the data throughput and access efficiency of server storage systems. NVMe (Non-Volatile Memory Express) SSDs based on the PCIe interface are widely used in server and data center storage systems. In some AI servers, local NVMe SSDs are used for system storage, data caching, and temporary data read/write operations, providing high-speed local storage support for computing workloads.

AI servers can be configured with NVMe SSDs of different specifications and form factors according to system architecture and storage requirements. As PCIe data rates increase, meeting signal integrity requirements calls for tighter control of PCB material properties, circuit fabrication precision, impedance, and via structures. Different servers and NVMe storage devices vary in interfaces, board structures, and storage configurations, so PCB materials, stack-up structures, and circuit designs need to be determined according to specific product specifications and design requirements. Relevant PCB applications may include PCBs within NVMe SSDs, as well as server backplanes and adapter boards used for NVMe storage connectivity. Their manufacturing requirements depend on the function of each board and the structure of its high-speed links.

HoYoGo is a professional AI server NVMe storage PCB manufacturer, with capabilities in high-reliability, high-precision, multilayer, and high-speed PCB manufacturing. AI server NVMe storage places demanding requirements on high-speed signal transmission, circuit fabrication precision, and long-term reliability. This article outlines key PCB manufacturing considerations, including manufacturing precision, low-loss materials, multilayer interconnection, via processing, and reliability.

PCB Manufacturing Precision for High-Speed PCIe Transmission

NVMe SSDs communicate with server systems through PCIe interfaces. As PCIe data rates increase, circuit fabrication precision and impedance consistency have a greater impact on signal transmission performance. For controlled-impedance traces, factors such as trace width, differential pair spacing, copper thickness, dielectric thickness, and material properties can affect actual impedance.

PCB manufacturing requires careful control of trace dimensions, copper thickness, dielectric thickness, etching uniformity, and other key parameters according to customer-specified PCB stack-ups, impedance targets, and technical requirements. Controlled-impedance traces should also be verified according to specified impedance targets and test conditions to confirm that actual impedance meets the product's technical requirements.

Low-Loss Materials and High-Speed Traces

High-speed signals traveling through a PCB are subject to both dielectric and conductor losses. As PCIe data rates increase, factors such as dielectric constant (Dk), dissipation factor (Df), copper foil surface roughness, and trace geometry can affect the transmission characteristics and losses of high-speed traces.

Some high-speed NVMe storage PCBs may use low-loss materials depending on PCIe data rates, trace length, loss budget, and product performance requirements. Different materials vary in resin systems, dimensional stability, and processing characteristics. Manufacturing conditions for lamination, drilling, and circuit fabrication therefore need to be determined according to the materials used, while consistency in dielectric thickness and material properties also requires careful control.

Multilayer PCBs and Storage Interconnection

NVMe storage devices in AI servers typically connect to the server platform through PCIe links and may communicate through system components such as CPUs or PCIe switches. For PCBs carrying multiple high-speed signals and power connections, multilayer structures provide the routing and interlayer interconnection space required for high-speed signals, power distribution, and ground networks.

For PCBs with high routing density and complex interlayer interconnections, processes such as layer-to-layer registration, lamination, drilling, and hole metallization require consistent control. Some high-density NVMe storage PCBs may also use HDI structures with microvias and other interlayer interconnection structures, depending on design requirements. For these PCBs, particular attention should be paid to layer-to-layer registration, hole position accuracy, laser drilling quality, and hole metallization.

High-Speed Vias and Signal Transmission

High-speed signals typically use vias for interlayer connections. For some high-speed PCIe traces, via stubs that are not part of the intended signal-layer connection may cause reflections and affect signal transmission performance.

Whether back drilling is required depends on the specific PCB stack-up, high-speed trace design, and product requirements. For PCBs using back drilling, key parameters such as back-drill depth, positional accuracy, and remaining stub length need to be controlled according to customer drawings, PCB stack-up structures, and target layer positions to ensure that via structures meet the specified design requirements.

PCB Reliability During Long-Term Operation

AI servers typically operate for extended periods, and controllers, NAND flash devices, and related power components in NVMe storage devices generate heat during continuous read and write operations. Heat dissipation of the storage device depends primarily on system and product thermal design, but the thermomechanical properties of PCB materials, interlayer bonding, and via interconnection quality can also affect long-term reliability.

For PCBs exposed to elevated temperatures for extended periods or subjected to temperature cycling, materials should be selected according to product operating conditions and reliability requirements. Lamination quality, interlayer bonding, and hole-wall copper plating quality should also be carefully controlled to reduce the risk of defects such as delamination and barrel cracking.

Consistency in Volume Manufacturing

Once PCBs for AI server NVMe storage enter volume production, maintaining consistency across production batches becomes essential. Variations in material properties, dielectric thickness, trace dimensions, copper thickness, and via structures can affect the impedance, dimensions, and electrical performance of finished PCBs.

Throughout volume production, from raw material management and inner- and outer-layer circuit fabrication to lamination, drilling, electroless copper deposition, electroplating, and final electrical testing, each manufacturing stage needs to be controlled according to product specifications and customer technical requirements to maintain consistent manufacturing quality and electrical performance across production batches.

Evolving PCB Manufacturing Requirements for AI Server NVMe Storage

As AI servers require higher local data access performance and storage throughput, the PCIe interfaces used by NVMe SSDs continue to support higher data rates, while storage density and capacity also continue to increase. As PCIe interfaces and storage devices advance, high-speed PCB manufacturing faces increasingly stringent requirements for material-related signal loss, circuit fabrication precision, impedance control, multilayer interconnection, and via processing.

AI servers vary in processors, PCIe architectures, NVMe SSD form factors, and storage configurations. PCB materials, stack-up structures, and manufacturing processes therefore need to be determined according to specific product specifications and customer technical requirements.

HoYoGo is a professional AI server NVMe storage PCB manufacturer, with capabilities in high-reliability, high-precision, multilayer, and high-speed PCB manufacturing. To meet the requirements of AI server NVMe storage for high-speed signal transmission, manufacturing precision, and long-term reliability, we provide customized PCB manufacturing services based on customer product specifications and technical requirements. Production and quality control are carried out according to applicable IPC standards and customer technical specifications, providing stable PCB manufacturing support for AI servers and high-speed storage products.