Inside AI servers, GPUs and ASICs function like high-speed brains, but the nervous system connecting them—the printed circuit board (PCB)—is becoming the decisive factor in performance. As data transfer rates surge from PCIe 5.0 to higher specifications, the physical limitations of traditional FR-4 materials are exposed; signal attenuation and distortion at high frequencies will lead to slowdowns or even interruptions in computation. This invisible war surrounding "signal integrity" centers on the upgrade of PCB materials. Introducing advanced materials with ultra-low loss characteristics, such as hydrocarbon resins or Teflon, while costly, is the only way to ensure the full release of AI computing power and overcome transmission bottlenecks, directly defining the architecture and performance ceiling of next-generation servers…