Optical Module Printed Circuit Board

An 8-layer hybrid PCB combining R-5775G high-speed laminate with IT-180A FR-4, blind-hole construction, 1.0±0.10mm thick, finished with Ni-Pd-Au for fine-pitch wire-bond and solder reliability. The board is built for QSFP, QSFP-DD, and OSFP optical transceivers, where electrical signals at 56G–112G PAM4 must drive a TIA, modulator driver, or DSP within millimeters of the optical engine. The R-5775G layers handle the high-speed differential pairs; IT-180A handles control and power. Blind vias keep the differential return path clean and shorten stubs. Sihui Fuji manages layer-to-layer registration, blind-hole accuracy, and copper plating uniformity to hold impedance and crosstalk targets. Used in 400G/800G datacenter modules, AI cluster interconnect, 5G fronthaul, and metro optical transport.