The Electromagnetic Interference Shielding And Thermal Design For High-Speed Broadband Optical Module

With the rapid development of data communication and telecommunication technology, the capacity of the optical network has surged and the high-speed optical module has become a hot research topic in the field of optical communication.The 100Gbit/s optical transceiver modules including CFP/CFP2/CFP4 and QSFP+package forms are mainly deployed in Ethernet core routers, switches, large-scale data center. Key issues on the heat dissipation and electromagnetic interference (EMI) for the high-speed broadband optical modules are widely studied, and the comprehensive design on module packaging has been deeply investigated. In this thesis, the research on heat dissipation and electromagnetic compatibility (EMC) of these high-speed optical modules is carried out.Firstly, the function and internal layout of module components is depicted and then we analyze the heat flow path inside the module, establish heat resistance model, conceive the heat dissipation structure preliminarily. The complex cooling structure with internal heat channeling is proposed to improve heat dissipation effect. Then, the thermal field distribution in the module is simulated by specialty software FLOTHERM based on thermofluidic dynamics, and the cooling structure is optimized to make the working temperature meet the performance requirements.As for the design of EMI shielding, TOSA/ROSA are enclosed into a shielding shell with a middle clapboard between components. The shielding enclosure adopts three-layer absorbing screen and such structure is optimized based on the photonic crystal (PC) isolated layer and nanocomposites absorbing layer. The reflection coefficient can be calculated and verified by finite element method (FEM) software HFSS. Also, due to the compactness of the module, the functional holes for fiber pigtail and heat flux channeling are requisite so that the shielding effectiveness (SE) is evaluated and analyzed by transmission line method based on S-parameters for such open-cell structures. Finally, the HFSS simulations validate the EMC design for high-speed broadband optical modules.Facing heat dissipation and EMI challenges for CFP/CFP2/CFP4 optical modules, the thesis proposes and demonstrates a feasible heat channeling and EMI shielding scheme to improve heat dissipation efficiency and suppress electromagnetic crosstalk. The work lays the theoretical foundation and engineering prototype for EMC and thermal management of high-speed broadband optical modules.