Multi-layer Electro-Optical Circuit Board Fabrication on Large Panel

Introduction of proposed electro-optical circuit board (EOCB) technologies based on embedded glass waveguides in the system enclosure of data storage, compute or switch platforms will be instrumental in accommodating the prohibitive bandwidth densities projected in exascale data centers, access networks and high performance computing environments in future. The main focus of this paper is, therefore, on the fabrication of large panel EOCB backplanes 350 mm × 465 mm with passive dual star interconnect topologies and stacking of multiple glass layers with double sided integrated optical waveguides. The waveguides are embedded inside glass panels using a two-step thermal ion exchange process. The fabricated embedded waveguides are characterized for propagation and coupling losses across different wavelength ranges and for different coupling arrangements. The modified EOCB fabrication process for these large panels is elucidated.