It consists of a photoelectric converter, driver circuit, receiver circuit, and control circuit. This guide serves as an in-depth resource for engineers, designers, and project managers involved in the development of optical module PCBs. It will explore the complete product lifecycle, from design principles and advanced material selection to the intricacies of precision fabrication. Definition: An Optical Module PCB is the internal circuit board of a transceiver (like SFP, QSFP, or OSFP) responsible for converting electrical signals to optical signals and vice versa. Critical Metrics: Signal integrity (insertion loss, return loss) and thermal management are the two. The optical module serves as a crucial component in optical fiber communication systems, operating at the physical layer, which is the lowest layer in the OSI model. Optical modules are used in applications including fiber-optic communication systems, data centers, and high-speed network systems to transmit and receive optical signals for data. Optical module circuit boards, also called optical module PCB s, are circuit boards used in optical fiber communication devices. With the increasing demand for massive parallel data computation in AI large-scale model training and inference, the world is facing greater demands for network bandwidth. When I first held an optical PCB prototype in 2022, its glowing green waveguide core shattered my 15-year-old concept of circuit boards. Glass fibers ran between copper traces like data superhighways.