Server Motherboard PCB

A 26-layer server motherboard PCB built on R-5775G low-loss laminate at 3.0±0.3mm thickness with ENIG surface finish. Back drilling is applied to remove via stubs on high-speed routes, preserving signal integrity for PCIe Gen5/Gen6 lanes, DDR5 memory channels, and 112G SerDes interfaces between CPU sockets, switch fabric, and accelerator cards. The high layer count enables dedicated reference planes for impedance-controlled differential pairs and clean power delivery to large-pin-count CPU and GPU sockets. ENIG provides flat, oxidation-resistant pads suitable for fine-pitch BGA assembly. Typical use cases include AI training servers, hyperscale compute nodes, switch backplanes, and 5G core network platforms. Production requires sequential lamination, controlled-depth back drilling, and tight registration across all 26 layers to maintain electrical performance at multi-gigahertz frequencies.